ClabureDB: Classified Bug-Reports Database

   /*
    * Core routines and tables shareable across OS platforms.
    *
    * Copyright (c) 1994-2002 Justin T. Gibbs.
    * Copyright (c) 2000-2002 Adaptec Inc.
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions, and the following disclaimer,
   *    without modification.
   * 2. Redistributions in binary form must reproduce at minimum a disclaimer
   *    substantially similar to the "NO WARRANTY" disclaimer below
   *    ("Disclaimer") and any redistribution must be conditioned upon
   *    including a substantially similar Disclaimer requirement for further
   *    binary redistribution.
   * 3. Neither the names of the above-listed copyright holders nor the names
   *    of any contributors may be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   *
   * Alternatively, this software may be distributed under the terms of the
   * GNU General Public License ("GPL") version 2 as published by the Free
   * Software Foundation.
   *
   * NO WARRANTY
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
   * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGES.
   *
   * $Id: //depot/aic7xxx/aic7xxx/aic7xxx.c#155 $
   */
  
  #ifdef __linux__
  #include "aic7xxx_osm.h"
  #include "aic7xxx_inline.h"
  #include "aicasm/aicasm_insformat.h"
  #else
  #include <dev/aic7xxx/aic7xxx_osm.h>
  #include <dev/aic7xxx/aic7xxx_inline.h>
  #include <dev/aic7xxx/aicasm/aicasm_insformat.h>
  #endif
  
  /***************************** Lookup Tables **********************************/
  static const char *const ahc_chip_names[] = {
          "NONE",
          "aic7770",
          "aic7850",
          "aic7855",
          "aic7859",
          "aic7860",
          "aic7870",
          "aic7880",
          "aic7895",
          "aic7895C",
          "aic7890/91",
          "aic7896/97",
          "aic7892",
          "aic7899"
  };
  static const u_int num_chip_names = ARRAY_SIZE(ahc_chip_names);
  
  /*
   * Hardware error codes.
   */
  struct ahc_hard_error_entry {
          uint8_t errno;
          const char *errmesg;
  };
  
  static const struct ahc_hard_error_entry ahc_hard_errors[] = {
          { ILLHADDR,        "Illegal Host Access" },
          { ILLSADDR,        "Illegal Sequencer Address referrenced" },
          { ILLOPCODE,        "Illegal Opcode in sequencer program" },
          { SQPARERR,        "Sequencer Parity Error" },
          { DPARERR,        "Data-path Parity Error" },
          { MPARERR,        "Scratch or SCB Memory Parity Error" },
          { PCIERRSTAT,        "PCI Error detected" },
          { CIOPARERR,        "CIOBUS Parity Error" },
  };
  static const u_int num_errors = ARRAY_SIZE(ahc_hard_errors);
  
  static const struct ahc_phase_table_entry ahc_phase_table[] =
  {
          { P_DATAOUT,        MSG_NOOP,                "in Data-out phase"        },
          { P_DATAIN,        MSG_INITIATOR_DET_ERR,        "in Data-in phase"        },
          { P_DATAOUT_DT,        MSG_NOOP,                "in DT Data-out phase"        },
          { P_DATAIN_DT,        MSG_INITIATOR_DET_ERR,        "in DT Data-in phase"        },
          { P_COMMAND,        MSG_NOOP,                "in Command phase"        },
          { P_MESGOUT,        MSG_NOOP,                "in Message-out phase"        },
         { P_STATUS,        MSG_INITIATOR_DET_ERR,        "in Status phase"        },
         { P_MESGIN,        MSG_PARITY_ERROR,        "in Message-in phase"        },
         { P_BUSFREE,        MSG_NOOP,                "while idle"                },
         { 0,                MSG_NOOP,                "in unknown phase"        }
 };
 
 /*
  * In most cases we only wish to itterate over real phases, so
  * exclude the last element from the count.
  */
 static const u_int num_phases = ARRAY_SIZE(ahc_phase_table) - 1;
 
 /*
  * Valid SCSIRATE values.  (p. 3-17)
  * Provides a mapping of tranfer periods in ns to the proper value to
  * stick in the scsixfer reg.
  */
 static const struct ahc_syncrate ahc_syncrates[] =
 {
       /* ultra2    fast/ultra  period     rate */
         { 0x42,      0x000,      9,      "80.0" },
         { 0x03,      0x000,     10,      "40.0" },
         { 0x04,      0x000,     11,      "33.0" },
         { 0x05,      0x100,     12,      "20.0" },
         { 0x06,      0x110,     15,      "16.0" },
         { 0x07,      0x120,     18,      "13.4" },
         { 0x08,      0x000,     25,      "10.0" },
         { 0x19,      0x010,     31,      "8.0"  },
         { 0x1a,      0x020,     37,      "6.67" },
         { 0x1b,      0x030,     43,      "5.7"  },
         { 0x1c,      0x040,     50,      "5.0"  },
         { 0x00,      0x050,     56,      "4.4"  },
         { 0x00,      0x060,     62,      "4.0"  },
         { 0x00,      0x070,     68,      "3.6"  },
         { 0x00,      0x000,      0,      NULL   }
 };
 
 /* Our Sequencer Program */
 #include "aic7xxx_seq.h"
 
 /**************************** Function Declarations ***************************/
 static void                ahc_force_renegotiation(struct ahc_softc *ahc,
                                                 struct ahc_devinfo *devinfo);
 static struct ahc_tmode_tstate*
                         ahc_alloc_tstate(struct ahc_softc *ahc,
                                          u_int scsi_id, char channel);
 #ifdef AHC_TARGET_MODE
 static void                ahc_free_tstate(struct ahc_softc *ahc,
                                         u_int scsi_id, char channel, int force);
 #endif
 static const struct ahc_syncrate*
                         ahc_devlimited_syncrate(struct ahc_softc *ahc,
                                                 struct ahc_initiator_tinfo *,
                                                 u_int *period,
                                                 u_int *ppr_options,
                                                 role_t role);
 static void                ahc_update_pending_scbs(struct ahc_softc *ahc);
 static void                ahc_fetch_devinfo(struct ahc_softc *ahc,
                                           struct ahc_devinfo *devinfo);
 static void                ahc_scb_devinfo(struct ahc_softc *ahc,
                                         struct ahc_devinfo *devinfo,
                                         struct scb *scb);
 static void                ahc_assert_atn(struct ahc_softc *ahc);
 static void                ahc_setup_initiator_msgout(struct ahc_softc *ahc,
                                                    struct ahc_devinfo *devinfo,
                                                    struct scb *scb);
 static void                ahc_build_transfer_msg(struct ahc_softc *ahc,
                                                struct ahc_devinfo *devinfo);
 static void                ahc_construct_sdtr(struct ahc_softc *ahc,
                                            struct ahc_devinfo *devinfo,
                                            u_int period, u_int offset);
 static void                ahc_construct_wdtr(struct ahc_softc *ahc,
                                            struct ahc_devinfo *devinfo,
                                            u_int bus_width);
 static void                ahc_construct_ppr(struct ahc_softc *ahc,
                                           struct ahc_devinfo *devinfo,
                                           u_int period, u_int offset,
                                           u_int bus_width, u_int ppr_options);
 static void                ahc_clear_msg_state(struct ahc_softc *ahc);
 static void                ahc_handle_proto_violation(struct ahc_softc *ahc);
 static void                ahc_handle_message_phase(struct ahc_softc *ahc);
 typedef enum {
         AHCMSG_1B,
         AHCMSG_2B,
         AHCMSG_EXT
 } ahc_msgtype;
 static int                ahc_sent_msg(struct ahc_softc *ahc, ahc_msgtype type,
                                      u_int msgval, int full);
 static int                ahc_parse_msg(struct ahc_softc *ahc,
                                       struct ahc_devinfo *devinfo);
 static int                ahc_handle_msg_reject(struct ahc_softc *ahc,
                                               struct ahc_devinfo *devinfo);
 static void                ahc_handle_ign_wide_residue(struct ahc_softc *ahc,
                                                 struct ahc_devinfo *devinfo);
 static void                ahc_reinitialize_dataptrs(struct ahc_softc *ahc);
 static void                ahc_handle_devreset(struct ahc_softc *ahc,
                                             struct ahc_devinfo *devinfo,
                                             cam_status status, char *message,
                                             int verbose_level);
 #ifdef AHC_TARGET_MODE
 static void                ahc_setup_target_msgin(struct ahc_softc *ahc,
                                                struct ahc_devinfo *devinfo,
                                                struct scb *scb);
 #endif
 
 static bus_dmamap_callback_t        ahc_dmamap_cb; 
 static void                ahc_build_free_scb_list(struct ahc_softc *ahc);
 static int                ahc_init_scbdata(struct ahc_softc *ahc);
 static void                ahc_fini_scbdata(struct ahc_softc *ahc);
 static void                ahc_qinfifo_requeue(struct ahc_softc *ahc,
                                             struct scb *prev_scb,
                                             struct scb *scb);
 static int                ahc_qinfifo_count(struct ahc_softc *ahc);
 static u_int                ahc_rem_scb_from_disc_list(struct ahc_softc *ahc,
                                                    u_int prev, u_int scbptr);
 static void                ahc_add_curscb_to_free_list(struct ahc_softc *ahc);
 static u_int                ahc_rem_wscb(struct ahc_softc *ahc,
                                      u_int scbpos, u_int prev);
 static void                ahc_reset_current_bus(struct ahc_softc *ahc);
 #ifdef AHC_DUMP_SEQ
 static void                ahc_dumpseq(struct ahc_softc *ahc);
 #endif
 static int                ahc_loadseq(struct ahc_softc *ahc);
 static int                ahc_check_patch(struct ahc_softc *ahc,
                                         const struct patch **start_patch,
                                         u_int start_instr, u_int *skip_addr);
 static void                ahc_download_instr(struct ahc_softc *ahc,
                                            u_int instrptr, uint8_t *dconsts);
 #ifdef AHC_TARGET_MODE
 static void                ahc_queue_lstate_event(struct ahc_softc *ahc,
                                                struct ahc_tmode_lstate *lstate,
                                                u_int initiator_id,
                                                u_int event_type,
                                                u_int event_arg);
 static void                ahc_update_scsiid(struct ahc_softc *ahc,
                                           u_int targid_mask);
 static int                ahc_handle_target_cmd(struct ahc_softc *ahc,
                                               struct target_cmd *cmd);
 #endif
 
 static u_int                ahc_index_busy_tcl(struct ahc_softc *ahc, u_int tcl);
 static void                ahc_unbusy_tcl(struct ahc_softc *ahc, u_int tcl);
 static void                ahc_busy_tcl(struct ahc_softc *ahc,
                                      u_int tcl, u_int busyid);
 
 /************************** SCB and SCB queue management **********************/
 static void                ahc_run_untagged_queues(struct ahc_softc *ahc);
 static void                ahc_run_untagged_queue(struct ahc_softc *ahc,
                                                struct scb_tailq *queue);
 
 /****************************** Initialization ********************************/
 static void                 ahc_alloc_scbs(struct ahc_softc *ahc);
 static void                 ahc_shutdown(void *arg);
 
 /*************************** Interrupt Services *******************************/
 static void                ahc_clear_intstat(struct ahc_softc *ahc);
 static void                ahc_run_qoutfifo(struct ahc_softc *ahc);
 #ifdef AHC_TARGET_MODE
 static void                ahc_run_tqinfifo(struct ahc_softc *ahc, int paused);
 #endif
 static void                ahc_handle_brkadrint(struct ahc_softc *ahc);
 static void                ahc_handle_seqint(struct ahc_softc *ahc, u_int intstat);
 static void                ahc_handle_scsiint(struct ahc_softc *ahc,
                                            u_int intstat);
 static void                ahc_clear_critical_section(struct ahc_softc *ahc);
 
 /***************************** Error Recovery *********************************/
 static void                ahc_freeze_devq(struct ahc_softc *ahc, struct scb *scb);
 static int                ahc_abort_scbs(struct ahc_softc *ahc, int target,
                                        char channel, int lun, u_int tag,
                                        role_t role, uint32_t status);
 static void                ahc_calc_residual(struct ahc_softc *ahc,
                                           struct scb *scb);
 
 /*********************** Untagged Transaction Routines ************************/
 static inline void        ahc_freeze_untagged_queues(struct ahc_softc *ahc);
 static inline void        ahc_release_untagged_queues(struct ahc_softc *ahc);
 
 /*
  * Block our completion routine from starting the next untagged
  * transaction for this target or target lun.
  */
 static inline void
 ahc_freeze_untagged_queues(struct ahc_softc *ahc)
 {
         if ((ahc->flags & AHC_SCB_BTT) == 0)
                 ahc->untagged_queue_lock++;
 }
 
 /*
  * Allow the next untagged transaction for this target or target lun
  * to be executed.  We use a counting semaphore to allow the lock
  * to be acquired recursively.  Once the count drops to zero, the
  * transaction queues will be run.
  */
 static inline void
 ahc_release_untagged_queues(struct ahc_softc *ahc)
 {
         if ((ahc->flags & AHC_SCB_BTT) == 0) {
                 ahc->untagged_queue_lock--;
                 if (ahc->untagged_queue_lock == 0)
                         ahc_run_untagged_queues(ahc);
         }
 }
 
 /************************* Sequencer Execution Control ************************/
 /*
  * Work around any chip bugs related to halting sequencer execution.
  * On Ultra2 controllers, we must clear the CIOBUS stretch signal by
  * reading a register that will set this signal and deassert it.
  * Without this workaround, if the chip is paused, by an interrupt or
  * manual pause while accessing scb ram, accesses to certain registers
  * will hang the system (infinite pci retries).
  */
 static void
 ahc_pause_bug_fix(struct ahc_softc *ahc)
 {
         if ((ahc->features & AHC_ULTRA2) != 0)
                 (void)ahc_inb(ahc, CCSCBCTL);
 }
 
 /*
  * Determine whether the sequencer has halted code execution.
  * Returns non-zero status if the sequencer is stopped.
  */
 int
 ahc_is_paused(struct ahc_softc *ahc)
 {
         return ((ahc_inb(ahc, HCNTRL) & PAUSE) != 0);
 }
 
 /*
  * Request that the sequencer stop and wait, indefinitely, for it
  * to stop.  The sequencer will only acknowledge that it is paused
  * once it has reached an instruction boundary and PAUSEDIS is
  * cleared in the SEQCTL register.  The sequencer may use PAUSEDIS
  * for critical sections.
  */
 void
 ahc_pause(struct ahc_softc *ahc)
 {
         ahc_outb(ahc, HCNTRL, ahc->pause);
 
         /*
          * Since the sequencer can disable pausing in a critical section, we
          * must loop until it actually stops.
          */
         while (ahc_is_paused(ahc) == 0)
                 ;
 
         ahc_pause_bug_fix(ahc);
 }
 
 /*
  * Allow the sequencer to continue program execution.
  * We check here to ensure that no additional interrupt
  * sources that would cause the sequencer to halt have been
  * asserted.  If, for example, a SCSI bus reset is detected
  * while we are fielding a different, pausing, interrupt type,
  * we don't want to release the sequencer before going back
  * into our interrupt handler and dealing with this new
  * condition.
  */
 void
 ahc_unpause(struct ahc_softc *ahc)
 {
         if ((ahc_inb(ahc, INTSTAT) & (SCSIINT | SEQINT | BRKADRINT)) == 0)
                 ahc_outb(ahc, HCNTRL, ahc->unpause);
 }
 
 /************************** Memory mapping routines ***************************/
 static struct ahc_dma_seg *
 ahc_sg_bus_to_virt(struct scb *scb, uint32_t sg_busaddr)
 {
         int sg_index;
 
         sg_index = (sg_busaddr - scb->sg_list_phys)/sizeof(struct ahc_dma_seg);
         /* sg_list_phys points to entry 1, not 0 */
         sg_index++;
 
         return (&scb->sg_list[sg_index]);
 }
 
 static uint32_t
 ahc_sg_virt_to_bus(struct scb *scb, struct ahc_dma_seg *sg)
 {
         int sg_index;
 
         /* sg_list_phys points to entry 1, not 0 */
         sg_index = sg - &scb->sg_list[1];
 
         return (scb->sg_list_phys + (sg_index * sizeof(*scb->sg_list)));
 }
 
 static uint32_t
 ahc_hscb_busaddr(struct ahc_softc *ahc, u_int index)
 {
         return (ahc->scb_data->hscb_busaddr
                 + (sizeof(struct hardware_scb) * index));
 }
 
 static void
 ahc_sync_scb(struct ahc_softc *ahc, struct scb *scb, int op)
 {
         ahc_dmamap_sync(ahc, ahc->scb_data->hscb_dmat,
                         ahc->scb_data->hscb_dmamap,
                         /*offset*/(scb->hscb - ahc->hscbs) * sizeof(*scb->hscb),
                         /*len*/sizeof(*scb->hscb), op);
 }
 
 void
 ahc_sync_sglist(struct ahc_softc *ahc, struct scb *scb, int op)
 {
         if (scb->sg_count == 0)
                 return;
 
         ahc_dmamap_sync(ahc, ahc->scb_data->sg_dmat, scb->sg_map->sg_dmamap,
                         /*offset*/(scb->sg_list - scb->sg_map->sg_vaddr)
                                 * sizeof(struct ahc_dma_seg),
                         /*len*/sizeof(struct ahc_dma_seg) * scb->sg_count, op);
 }
 
 #ifdef AHC_TARGET_MODE
 static uint32_t
 ahc_targetcmd_offset(struct ahc_softc *ahc, u_int index)
 {
         return (((uint8_t *)&ahc->targetcmds[index]) - ahc->qoutfifo);
 }
 #endif
 
 /*********************** Miscelaneous Support Functions ***********************/
 /*
  * Determine whether the sequencer reported a residual
  * for this SCB/transaction.
  */
 static void
 ahc_update_residual(struct ahc_softc *ahc, struct scb *scb)
 {
         uint32_t sgptr;
 
         sgptr = ahc_le32toh(scb->hscb->sgptr);
         if ((sgptr & SG_RESID_VALID) != 0)
                 ahc_calc_residual(ahc, scb);
 }
 
 /*
  * Return pointers to the transfer negotiation information
  * for the specified our_id/remote_id pair.
  */
 struct ahc_initiator_tinfo *
 ahc_fetch_transinfo(struct ahc_softc *ahc, char channel, u_int our_id,
                     u_int remote_id, struct ahc_tmode_tstate **tstate)
 {
         /*
          * Transfer data structures are stored from the perspective
          * of the target role.  Since the parameters for a connection
          * in the initiator role to a given target are the same as
          * when the roles are reversed, we pretend we are the target.
          */
         if (channel == 'B')
                 our_id += 8;
         *tstate = ahc->enabled_targets[our_id];
         return (&(*tstate)->transinfo[remote_id]);
 }
 
 uint16_t
 ahc_inw(struct ahc_softc *ahc, u_int port)
 {
         uint16_t r = ahc_inb(ahc, port+1) << 8;
         return r | ahc_inb(ahc, port);
 }
 
 void
 ahc_outw(struct ahc_softc *ahc, u_int port, u_int value)
 {
         ahc_outb(ahc, port, value & 0xFF);
         ahc_outb(ahc, port+1, (value >> 8) & 0xFF);
 }
 
 uint32_t
 ahc_inl(struct ahc_softc *ahc, u_int port)
 {
         return ((ahc_inb(ahc, port))
               | (ahc_inb(ahc, port+1) << 8)
               | (ahc_inb(ahc, port+2) << 16)
               | (ahc_inb(ahc, port+3) << 24));
 }
 
 void
 ahc_outl(struct ahc_softc *ahc, u_int port, uint32_t value)
 {
         ahc_outb(ahc, port, (value) & 0xFF);
         ahc_outb(ahc, port+1, ((value) >> 8) & 0xFF);
         ahc_outb(ahc, port+2, ((value) >> 16) & 0xFF);
         ahc_outb(ahc, port+3, ((value) >> 24) & 0xFF);
 }
 
 uint64_t
 ahc_inq(struct ahc_softc *ahc, u_int port)
 {
         return ((ahc_inb(ahc, port))
               | (ahc_inb(ahc, port+1) << 8)
               | (ahc_inb(ahc, port+2) << 16)
               | (ahc_inb(ahc, port+3) << 24)
               | (((uint64_t)ahc_inb(ahc, port+4)) << 32)
               | (((uint64_t)ahc_inb(ahc, port+5)) << 40)
               | (((uint64_t)ahc_inb(ahc, port+6)) << 48)
               | (((uint64_t)ahc_inb(ahc, port+7)) << 56));
 }
 
 void
 ahc_outq(struct ahc_softc *ahc, u_int port, uint64_t value)
 {
         ahc_outb(ahc, port, value & 0xFF);
         ahc_outb(ahc, port+1, (value >> 8) & 0xFF);
         ahc_outb(ahc, port+2, (value >> 16) & 0xFF);
         ahc_outb(ahc, port+3, (value >> 24) & 0xFF);
         ahc_outb(ahc, port+4, (value >> 32) & 0xFF);
         ahc_outb(ahc, port+5, (value >> 40) & 0xFF);
         ahc_outb(ahc, port+6, (value >> 48) & 0xFF);
         ahc_outb(ahc, port+7, (value >> 56) & 0xFF);
 }
 
 /*
  * Get a free scb. If there are none, see if we can allocate a new SCB.
  */
 struct scb *
 ahc_get_scb(struct ahc_softc *ahc)
 {
         struct scb *scb;
 
         if ((scb = SLIST_FIRST(&ahc->scb_data->free_scbs)) == NULL) {
                 ahc_alloc_scbs(ahc);
                 scb = SLIST_FIRST(&ahc->scb_data->free_scbs);
                 if (scb == NULL)
                         return (NULL);
         }
         SLIST_REMOVE_HEAD(&ahc->scb_data->free_scbs, links.sle);
         return (scb);
 }
 
 /*
  * Return an SCB resource to the free list.
  */
 void
 ahc_free_scb(struct ahc_softc *ahc, struct scb *scb)
 {
         struct hardware_scb *hscb;
 
         hscb = scb->hscb;
         /* Clean up for the next user */
         ahc->scb_data->scbindex[hscb->tag] = NULL;
         scb->flags = SCB_FREE;
         hscb->control = 0;
 
         SLIST_INSERT_HEAD(&ahc->scb_data->free_scbs, scb, links.sle);
 
         /* Notify the OSM that a resource is now available. */
         ahc_platform_scb_free(ahc, scb);
 }
 
 struct scb *
 ahc_lookup_scb(struct ahc_softc *ahc, u_int tag)
 {
         struct scb* scb;
 
         scb = ahc->scb_data->scbindex[tag];
         if (scb != NULL)
                 ahc_sync_scb(ahc, scb,
                              BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
         return (scb);
 }
 
 static void
 ahc_swap_with_next_hscb(struct ahc_softc *ahc, struct scb *scb)
 {
         struct hardware_scb *q_hscb;
         u_int  saved_tag;
 
         /*
          * Our queuing method is a bit tricky.  The card
          * knows in advance which HSCB to download, and we
          * can't disappoint it.  To achieve this, the next
          * SCB to download is saved off in ahc->next_queued_scb.
          * When we are called to queue "an arbitrary scb",
          * we copy the contents of the incoming HSCB to the one
          * the sequencer knows about, swap HSCB pointers and
          * finally assign the SCB to the tag indexed location
          * in the scb_array.  This makes sure that we can still
          * locate the correct SCB by SCB_TAG.
          */
         q_hscb = ahc->next_queued_scb->hscb;
         saved_tag = q_hscb->tag;
         memcpy(q_hscb, scb->hscb, sizeof(*scb->hscb));
         if ((scb->flags & SCB_CDB32_PTR) != 0) {
                 q_hscb->shared_data.cdb_ptr =
                     ahc_htole32(ahc_hscb_busaddr(ahc, q_hscb->tag)
                               + offsetof(struct hardware_scb, cdb32));
         }
         q_hscb->tag = saved_tag;
         q_hscb->next = scb->hscb->tag;
 
         /* Now swap HSCB pointers. */
         ahc->next_queued_scb->hscb = scb->hscb;
         scb->hscb = q_hscb;
 
         /* Now define the mapping from tag to SCB in the scbindex */
         ahc->scb_data->scbindex[scb->hscb->tag] = scb;
 }
 
 /*
  * Tell the sequencer about a new transaction to execute.
  */
 void
 ahc_queue_scb(struct ahc_softc *ahc, struct scb *scb)
 {
         ahc_swap_with_next_hscb(ahc, scb);
 
         if (scb->hscb->tag == SCB_LIST_NULL
          || scb->hscb->next == SCB_LIST_NULL)
                 panic("Attempt to queue invalid SCB tag %x:%x\n",
                       scb->hscb->tag, scb->hscb->next);
 
         /*
          * Setup data "oddness".
          */
         scb->hscb->lun &= LID;
         if (ahc_get_transfer_length(scb) & 0x1)
                 scb->hscb->lun |= SCB_XFERLEN_ODD;
 
         /*
          * Keep a history of SCBs we've downloaded in the qinfifo.
          */
         ahc->qinfifo[ahc->qinfifonext++] = scb->hscb->tag;
 
         /*
          * Make sure our data is consistent from the
          * perspective of the adapter.
          */
         ahc_sync_scb(ahc, scb, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
 
         /* Tell the adapter about the newly queued SCB */
         if ((ahc->features & AHC_QUEUE_REGS) != 0) {
                 ahc_outb(ahc, HNSCB_QOFF, ahc->qinfifonext);
         } else {
                 if ((ahc->features & AHC_AUTOPAUSE) == 0)
                         ahc_pause(ahc);
                 ahc_outb(ahc, KERNEL_QINPOS, ahc->qinfifonext);
                 if ((ahc->features & AHC_AUTOPAUSE) == 0)
                         ahc_unpause(ahc);
         }
 }
 
 struct scsi_sense_data *
 ahc_get_sense_buf(struct ahc_softc *ahc, struct scb *scb)
 {
         int offset;
 
         offset = scb - ahc->scb_data->scbarray;
         return (&ahc->scb_data->sense[offset]);
 }
 
 static uint32_t
 ahc_get_sense_bufaddr(struct ahc_softc *ahc, struct scb *scb)
 {
         int offset;
 
         offset = scb - ahc->scb_data->scbarray;
         return (ahc->scb_data->sense_busaddr
               + (offset * sizeof(struct scsi_sense_data)));
 }
 
 /************************** Interrupt Processing ******************************/
 static void
 ahc_sync_qoutfifo(struct ahc_softc *ahc, int op)
 {
         ahc_dmamap_sync(ahc, ahc->shared_data_dmat, ahc->shared_data_dmamap,
                         /*offset*/0, /*len*/256, op);
 }
 
 static void
 ahc_sync_tqinfifo(struct ahc_softc *ahc, int op)
 {
 #ifdef AHC_TARGET_MODE
         if ((ahc->flags & AHC_TARGETROLE) != 0) {
                 ahc_dmamap_sync(ahc, ahc->shared_data_dmat,
                                 ahc->shared_data_dmamap,
                                 ahc_targetcmd_offset(ahc, 0),
                                 sizeof(struct target_cmd) * AHC_TMODE_CMDS,
                                 op);
         }
 #endif
 }
 
 /*
  * See if the firmware has posted any completed commands
  * into our in-core command complete fifos.
  */
 #define AHC_RUN_QOUTFIFO 0x1
 #define AHC_RUN_TQINFIFO 0x2
 static u_int
 ahc_check_cmdcmpltqueues(struct ahc_softc *ahc)
 {
         u_int retval;
 
         retval = 0;
         ahc_dmamap_sync(ahc, ahc->shared_data_dmat, ahc->shared_data_dmamap,
                         /*offset*/ahc->qoutfifonext, /*len*/1,
                         BUS_DMASYNC_POSTREAD);
         if (ahc->qoutfifo[ahc->qoutfifonext] != SCB_LIST_NULL)
                 retval |= AHC_RUN_QOUTFIFO;
 #ifdef AHC_TARGET_MODE
         if ((ahc->flags & AHC_TARGETROLE) != 0
          && (ahc->flags & AHC_TQINFIFO_BLOCKED) == 0) {
                 ahc_dmamap_sync(ahc, ahc->shared_data_dmat,
                                 ahc->shared_data_dmamap,
                                 ahc_targetcmd_offset(ahc, ahc->tqinfifofnext),
                                 /*len*/sizeof(struct target_cmd),
                                 BUS_DMASYNC_POSTREAD);
                 if (ahc->targetcmds[ahc->tqinfifonext].cmd_valid != 0)
                         retval |= AHC_RUN_TQINFIFO;
         }
 #endif
         return (retval);
 }
 
 /*
  * Catch an interrupt from the adapter
  */
 int
 ahc_intr(struct ahc_softc *ahc)
 {
         u_int        intstat;
 
         if ((ahc->pause & INTEN) == 0) {
                 /*
                  * Our interrupt is not enabled on the chip
                  * and may be disabled for re-entrancy reasons,
                  * so just return.  This is likely just a shared
                  * interrupt.
                  */
                 return (0);
         }
         /*
          * Instead of directly reading the interrupt status register,
          * infer the cause of the interrupt by checking our in-core
          * completion queues.  This avoids a costly PCI bus read in
          * most cases.
          */
         if ((ahc->flags & (AHC_ALL_INTERRUPTS|AHC_EDGE_INTERRUPT)) == 0
          && (ahc_check_cmdcmpltqueues(ahc) != 0))
                 intstat = CMDCMPLT;
         else {
                 intstat = ahc_inb(ahc, INTSTAT);
         }
 
         if ((intstat & INT_PEND) == 0) {
 #if AHC_PCI_CONFIG > 0
                 if (ahc->unsolicited_ints > 500) {
                         ahc->unsolicited_ints = 0;
                         if ((ahc->chip & AHC_PCI) != 0
                          && (ahc_inb(ahc, ERROR) & PCIERRSTAT) != 0)
                                 ahc->bus_intr(ahc);
                 }
 #endif
                 ahc->unsolicited_ints++;
                 return (0);
         }
         ahc->unsolicited_ints = 0;
 
         if (intstat & CMDCMPLT) {
                 ahc_outb(ahc, CLRINT, CLRCMDINT);
 
                 /*
                  * Ensure that the chip sees that we've cleared
                  * this interrupt before we walk the output fifo.
                  * Otherwise, we may, due to posted bus writes,
                  * clear the interrupt after we finish the scan,
                  * and after the sequencer has added new entries
                  * and asserted the interrupt again.
                  */
                 ahc_flush_device_writes(ahc);
                 ahc_run_qoutfifo(ahc);
 #ifdef AHC_TARGET_MODE
                 if ((ahc->flags & AHC_TARGETROLE) != 0)
                         ahc_run_tqinfifo(ahc, /*paused*/FALSE);
 #endif
         }
 
         /*
          * Handle statuses that may invalidate our cached
          * copy of INTSTAT separately.
          */
         if (intstat == 0xFF && (ahc->features & AHC_REMOVABLE) != 0) {
                 /* Hot eject.  Do nothing */
         } else if (intstat & BRKADRINT) {
                 ahc_handle_brkadrint(ahc);
         } else if ((intstat & (SEQINT|SCSIINT)) != 0) {
 
                 ahc_pause_bug_fix(ahc);
 
                 if ((intstat & SEQINT) != 0)
                         ahc_handle_seqint(ahc, intstat);
 
                 if ((intstat & SCSIINT) != 0)
                         ahc_handle_scsiint(ahc, intstat);
         }
         return (1);
 }
 
 /************************* Sequencer Execution Control ************************/
 /*
  * Restart the sequencer program from address zero
  */
 static void
 ahc_restart(struct ahc_softc *ahc)
 {
         uint8_t        sblkctl;
 
         ahc_pause(ahc);
 
         /* No more pending messages. */
         ahc_clear_msg_state(ahc);
 
         ahc_outb(ahc, SCSISIGO, 0);                /* De-assert BSY */
         ahc_outb(ahc, MSG_OUT, MSG_NOOP);        /* No message to send */
         ahc_outb(ahc, SXFRCTL1, ahc_inb(ahc, SXFRCTL1) & ~BITBUCKET);
         ahc_outb(ahc, LASTPHASE, P_BUSFREE);
         ahc_outb(ahc, SAVED_SCSIID, 0xFF);
         ahc_outb(ahc, SAVED_LUN, 0xFF);
 
         /*
          * Ensure that the sequencer's idea of TQINPOS
          * matches our own.  The sequencer increments TQINPOS
          * only after it sees a DMA complete and a reset could
          * occur before the increment leaving the kernel to believe
          * the command arrived but the sequencer to not.
          */
         ahc_outb(ahc, TQINPOS, ahc->tqinfifonext);
 
         /* Always allow reselection */
         ahc_outb(ahc, SCSISEQ,
                  ahc_inb(ahc, SCSISEQ_TEMPLATE) & (ENSELI|ENRSELI|ENAUTOATNP));
         if ((ahc->features & AHC_CMD_CHAN) != 0) {
                 /* Ensure that no DMA operations are in progress */
                 ahc_outb(ahc, CCSCBCNT, 0);
                 ahc_outb(ahc, CCSGCTL, 0);
                 ahc_outb(ahc, CCSCBCTL, 0);
         }
         /*
          * If we were in the process of DMA'ing SCB data into
          * an SCB, replace that SCB on the free list.  This prevents
          * an SCB leak.
          */
         if ((ahc_inb(ahc, SEQ_FLAGS2) & SCB_DMA) != 0) {
                 ahc_add_curscb_to_free_list(ahc);
                 ahc_outb(ahc, SEQ_FLAGS2,
                          ahc_inb(ahc, SEQ_FLAGS2) & ~SCB_DMA);
         }
 
         /*
          * Clear any pending sequencer interrupt.  It is no
          * longer relevant since we're resetting the Program
          * Counter.
          */
         ahc_outb(ahc, CLRINT, CLRSEQINT);
 
         ahc_outb(ahc, MWI_RESIDUAL, 0);
         ahc_outb(ahc, SEQCTL, ahc->seqctl);
         ahc_outb(ahc, SEQADDR0, 0);
         ahc_outb(ahc, SEQADDR1, 0);
 
         /*
          * Take the LED out of diagnostic mode on PM resume, too
          */
         sblkctl = ahc_inb(ahc, SBLKCTL);
         ahc_outb(ahc, SBLKCTL, (sblkctl & ~(DIAGLEDEN|DIAGLEDON)));
 
         ahc_unpause(ahc);
 }
 
 /************************* Input/Output Queues ********************************/
 static void
 ahc_run_qoutfifo(struct ahc_softc *ahc)
 {
         struct scb *scb;
         u_int  scb_index;
 
         ahc_sync_qoutfifo(ahc, BUS_DMASYNC_POSTREAD);
         while (ahc->qoutfifo[ahc->qoutfifonext] != SCB_LIST_NULL) {
 
                 scb_index = ahc->qoutfifo[ahc->qoutfifonext];
                 if ((ahc->qoutfifonext & 0x03) == 0x03) {
                         u_int modnext;
 
                         /*
                          * Clear 32bits of QOUTFIFO at a time
                          * so that we don't clobber an incoming
                          * byte DMA to the array on architectures
                          * that only support 32bit load and store
                          * operations.
                          */
                         modnext = ahc->qoutfifonext & ~0x3;
                         *((uint32_t *)(&ahc->qoutfifo[modnext])) = 0xFFFFFFFFUL;
                         ahc_dmamap_sync(ahc, ahc->shared_data_dmat,
                                         ahc->shared_data_dmamap,
                                         /*offset*/modnext, /*len*/4,
                                         BUS_DMASYNC_PREREAD);
                 }
                 ahc->qoutfifonext++;
 
                 scb = ahc_lookup_scb(ahc, scb_index);
                 if (scb == NULL) {
                         printf("%s: WARNING no command for scb %d "
                                "(cmdcmplt)\nQOUTPOS = %d\n",
                                ahc_name(ahc), scb_index,
                                (ahc->qoutfifonext - 1) & 0xFF);
                         continue;
                 }
 
                 /*
                  * Save off the residual
                  * if there is one.
                  */
                 ahc_update_residual(ahc, scb);
                 ahc_done(ahc, scb);
         }
 }
 
 static void
 ahc_run_untagged_queues(struct ahc_softc *ahc)
 {
         int i;
 
         for (i = 0; i < 16; i++)
                 ahc_run_untagged_queue(ahc, &ahc->untagged_queues[i]);
 }
 
 static void
 ahc_run_untagged_queue(struct ahc_softc *ahc, struct scb_tailq *queue)
 {
         struct scb *scb;
 
         if (ahc->untagged_queue_lock != 0)
                 return;
 
         if ((scb = TAILQ_FIRST(queue)) != NULL
          && (scb->flags & SCB_ACTIVE) == 0) {
                 scb->flags |= SCB_ACTIVE;
                 ahc_queue_scb(ahc, scb);
         }
 }
 
 /************************* Interrupt Handling *********************************/
 static void
 ahc_handle_brkadrint(struct ahc_softc *ahc)
 {
         /*
          * We upset the sequencer :-(
          * Lookup the error message
          */
         int i;
         int error;
 
         error = ahc_inb(ahc, ERROR);
         for (i = 0; error != 1 && i < num_errors; i++)
                 error >>= 1;
         printf("%s: brkadrint, %s at seqaddr = 0x%x\n",
                ahc_name(ahc), ahc_hard_errors[i].errmesg,
                ahc_inb(ahc, SEQADDR0) |
                (ahc_inb(ahc, SEQADDR1) << 8));
 
         ahc_dump_card_state(ahc);
 
         /* Tell everyone that this HBA is no longer available */
         ahc_abort_scbs(ahc, CAM_TARGET_WILDCARD, ALL_CHANNELS,
                        CAM_LUN_WILDCARD, SCB_LIST_NULL, ROLE_UNKNOWN,
                        CAM_NO_HBA);
 
         /* Disable all interrupt sources by resetting the controller */
         ahc_shutdown(ahc);
 }
 
 static void
 ahc_handle_seqint(struct ahc_softc *ahc, u_int intstat)
 {
         struct scb *scb;
         struct ahc_devinfo devinfo;
         
         ahc_fetch_devinfo(ahc, &devinfo);
 
         /*
          * Clear the upper byte that holds SEQINT status
          * codes and clear the SEQINT bit. We will unpause
          * the sequencer, if appropriate, after servicing
          * the request.
          */
         ahc_outb(ahc, CLRINT, CLRSEQINT);
         switch (intstat & SEQINT_MASK) {
         case BAD_STATUS:
        {
                u_int  scb_index;
                struct hardware_scb *hscb;

                /*
                 * Set the default return value to 0 (don't
                 * send sense).  The sense code will change
                 * this if needed.
                 */
                ahc_outb(ahc, RETURN_1, 0);

                /*
                 * The sequencer will notify us when a command
                 * has an error that would be of interest to
                 * the kernel.  This allows us to leave the sequencer
                 * running in the common case of command completes
                 * without error.  The sequencer will already have
                 * dma'd the SCB back up to us, so we can reference
                 * the in kernel copy directly.
                 */
                scb_index = ahc_inb(ahc, SCB_TAG);
                scb = ahc_lookup_scb(ahc, scb_index);
                if (scb == NULL) {
                        ahc_print_devinfo(ahc, &devinfo);
                        printf("ahc_intr - referenced scb "
                               "not valid during seqint 0x%x scb(%d)\n",
                               intstat, scb_index);
                        ahc_dump_card_state(ahc);
                        panic("for safety");
                        goto unpause;
                }

                hscb = scb->hscb; 

                /* Don't want to clobber the original sense code */
                if ((scb->flags & SCB_SENSE) != 0) {
                        /*
                         * Clear the SCB_SENSE Flag and have
                         * the sequencer do a normal command
                         * complete.
                         */
                        scb->flags &= ~SCB_SENSE;
                        ahc_set_transaction_status(scb, CAM_AUTOSENSE_FAIL);
                        break;
                }
                ahc_set_transaction_status(scb, CAM_SCSI_STATUS_ERROR);
                /* Freeze the queue until the client sees the error. */
                ahc_freeze_devq(ahc, scb);
                ahc_freeze_scb(scb);
                ahc_set_scsi_status(scb, hscb->shared_data.status.scsi_status);
                switch (hscb->shared_data.status.scsi_status) {
                case SCSI_STATUS_OK:
                        printf("%s: Interrupted for staus of 0???\n",
                               ahc_name(ahc));
                        break;
                case SCSI_STATUS_CMD_TERMINATED:
                case SCSI_STATUS_CHECK_COND:
                {
                        struct ahc_dma_seg *sg;
                        struct scsi_sense *sc;
                        struct ahc_initiator_tinfo *targ_info;
                        struct ahc_tmode_tstate *tstate;
                        struct ahc_transinfo *tinfo;
#ifdef AHC_DEBUG
                        if (ahc_debug & AHC_SHOW_SENSE) {
                                ahc_print_path(ahc, scb);
                                printf("SCB %d: requests Check Status\n",
                                       scb->hscb->tag);
                        }
#endif

                        if (ahc_perform_autosense(scb) == 0)
                                break;

                        targ_info = ahc_fetch_transinfo(ahc,
                                                        devinfo.channel,
                                                        devinfo.our_scsiid,
                                                        devinfo.target,
                                                        &tstate);
                        tinfo = &targ_info->curr;
                        sg = scb->sg_list;
                        sc = (struct scsi_sense *)(&hscb->shared_data.cdb); 
                        /*
                         * Save off the residual if there is one.
                         */
                        ahc_update_residual(ahc, scb);
#ifdef AHC_DEBUG
                        if (ahc_debug & AHC_SHOW_SENSE) {
                                ahc_print_path(ahc, scb);
                                printf("Sending Sense\n");
                        }
#endif
                        sg->addr = ahc_get_sense_bufaddr(ahc, scb);
                        sg->len = ahc_get_sense_bufsize(ahc, scb);
                        sg->len |= AHC_DMA_LAST_SEG;

                        /* Fixup byte order */
                        sg->addr = ahc_htole32(sg->addr);
                        sg->len = ahc_htole32(sg->len);

                        sc->opcode = REQUEST_SENSE;
                        sc->byte2 = 0;
                        if (tinfo->protocol_version <= SCSI_REV_2
                         && SCB_GET_LUN(scb) < 8)
                                sc->byte2 = SCB_GET_LUN(scb) << 5;
                        sc->unused[0] = 0;
                        sc->unused[1] = 0;
                        sc->length = sg->len;
                        sc->control = 0;

                        /*
                         * We can't allow the target to disconnect.
                         * This will be an untagged transaction and
                         * having the target disconnect will make this
                         * transaction indestinguishable from outstanding
                         * tagged transactions.
                         */
                        hscb->control = 0;

                        /*
                         * This request sense could be because the
                         * the device lost power or in some other
                         * way has lost our transfer negotiations.
                         * Renegotiate if appropriate.  Unit attention
                         * errors will be reported before any data
                         * phases occur.
                         */
                        if (ahc_get_residual(scb) 
                         == ahc_get_transfer_length(scb)) {
                                ahc_update_neg_request(ahc, &devinfo,
                                                       tstate, targ_info,
                                                       AHC_NEG_IF_NON_ASYNC);
                        }
                        if (tstate->auto_negotiate & devinfo.target_mask) {
                                hscb->control |= MK_MESSAGE;
                                scb->flags &= ~SCB_NEGOTIATE;
                                scb->flags |= SCB_AUTO_NEGOTIATE;
                        }
                        hscb->cdb_len = sizeof(*sc);
                        hscb->dataptr = sg->addr; 
                        hscb->datacnt = sg->len;
                        hscb->sgptr = scb->sg_list_phys | SG_FULL_RESID;
                        hscb->sgptr = ahc_htole32(hscb->sgptr);
                        scb->sg_count = 1;
                        scb->flags |= SCB_SENSE;
                        ahc_qinfifo_requeue_tail(ahc, scb);
                        ahc_outb(ahc, RETURN_1, SEND_SENSE);
                        /*
                         * Ensure we have enough time to actually
                         * retrieve the sense.
                         */
                        ahc_scb_timer_reset(scb, 5 * 1000000);
                        break;
                }
                default:
                        break;
                }
                break;
        }
        case NO_MATCH:
        {
                /* Ensure we don't leave the selection hardware on */
                ahc_outb(ahc, SCSISEQ,
                         ahc_inb(ahc, SCSISEQ) & (ENSELI|ENRSELI|ENAUTOATNP));

                printf("%s:%c:%d: no active SCB for reconnecting "
                       "target - issuing BUS DEVICE RESET\n",
                       ahc_name(ahc), devinfo.channel, devinfo.target);
                printf("SAVED_SCSIID == 0x%x, SAVED_LUN == 0x%x, "
                       "ARG_1 == 0x%x ACCUM = 0x%x\n",
                       ahc_inb(ahc, SAVED_SCSIID), ahc_inb(ahc, SAVED_LUN),
                       ahc_inb(ahc, ARG_1), ahc_inb(ahc, ACCUM));
                printf("SEQ_FLAGS == 0x%x, SCBPTR == 0x%x, BTT == 0x%x, "
                       "SINDEX == 0x%x\n",
                       ahc_inb(ahc, SEQ_FLAGS), ahc_inb(ahc, SCBPTR),
                       ahc_index_busy_tcl(ahc,
                            BUILD_TCL(ahc_inb(ahc, SAVED_SCSIID),
                                      ahc_inb(ahc, SAVED_LUN))),
                       ahc_inb(ahc, SINDEX));
                printf("SCSIID == 0x%x, SCB_SCSIID == 0x%x, SCB_LUN == 0x%x, "
                       "SCB_TAG == 0x%x, SCB_CONTROL == 0x%x\n",
                       ahc_inb(ahc, SCSIID), ahc_inb(ahc, SCB_SCSIID),
                       ahc_inb(ahc, SCB_LUN), ahc_inb(ahc, SCB_TAG),
                       ahc_inb(ahc, SCB_CONTROL));
                printf("SCSIBUSL == 0x%x, SCSISIGI == 0x%x\n",
                       ahc_inb(ahc, SCSIBUSL), ahc_inb(ahc, SCSISIGI));
                printf("SXFRCTL0 == 0x%x\n", ahc_inb(ahc, SXFRCTL0));
                printf("SEQCTL == 0x%x\n", ahc_inb(ahc, SEQCTL));
                ahc_dump_card_state(ahc);
                ahc->msgout_buf[0] = MSG_BUS_DEV_RESET;
                ahc->msgout_len = 1;
                ahc->msgout_index = 0;
                ahc->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                ahc_outb(ahc, MSG_OUT, HOST_MSG);
                ahc_assert_atn(ahc);
                break;
        }
        case SEND_REJECT: 
        {
                u_int rejbyte = ahc_inb(ahc, ACCUM);
                printf("%s:%c:%d: Warning - unknown message received from "
                       "target (0x%x).  Rejecting\n", 
                       ahc_name(ahc), devinfo.channel, devinfo.target, rejbyte);
                break; 
        }
        case PROTO_VIOLATION:
        {
                ahc_handle_proto_violation(ahc);
                break;
        }
        case IGN_WIDE_RES:
                ahc_handle_ign_wide_residue(ahc, &devinfo);
                break;
        case PDATA_REINIT:
                ahc_reinitialize_dataptrs(ahc);
                break;
        case BAD_PHASE:
        {
                u_int lastphase;

                lastphase = ahc_inb(ahc, LASTPHASE);
                printf("%s:%c:%d: unknown scsi bus phase %x, "
                       "lastphase = 0x%x.  Attempting to continue\n",
                       ahc_name(ahc), devinfo.channel, devinfo.target,
                       lastphase, ahc_inb(ahc, SCSISIGI));
                break;
        }
        case MISSED_BUSFREE:
        {
                u_int lastphase;

                lastphase = ahc_inb(ahc, LASTPHASE);
                printf("%s:%c:%d: Missed busfree. "
                       "Lastphase = 0x%x, Curphase = 0x%x\n",
                       ahc_name(ahc), devinfo.channel, devinfo.target,
                       lastphase, ahc_inb(ahc, SCSISIGI));
                ahc_restart(ahc);
                return;
        }
        case HOST_MSG_LOOP:
        {
                /*
                 * The sequencer has encountered a message phase
                 * that requires host assistance for completion.
                 * While handling the message phase(s), we will be
                 * notified by the sequencer after each byte is
                 * transfered so we can track bus phase changes.
                 *
                 * If this is the first time we've seen a HOST_MSG_LOOP
                 * interrupt, initialize the state of the host message
                 * loop.
                 */
                if (ahc->msg_type == MSG_TYPE_NONE) {
                        struct scb *scb;
                        u_int scb_index;
                        u_int bus_phase;

                        bus_phase = ahc_inb(ahc, SCSISIGI) & PHASE_MASK;
                        if (bus_phase != P_MESGIN
                         && bus_phase != P_MESGOUT) {
                                printf("ahc_intr: HOST_MSG_LOOP bad "
                                       "phase 0x%x\n",
                                      bus_phase);
                                /*
                                 * Probably transitioned to bus free before
                                 * we got here.  Just punt the message.
                                 */
                                ahc_clear_intstat(ahc);
                                ahc_restart(ahc);
                                return;
                        }

                        scb_index = ahc_inb(ahc, SCB_TAG);
                        scb = ahc_lookup_scb(ahc, scb_index);
                        if (devinfo.role == ROLE_INITIATOR) {
                                if (bus_phase == P_MESGOUT) {
                                        if (scb == NULL)
                                                panic("HOST_MSG_LOOP with "
                                                      "invalid SCB %x\n",
                                                      scb_index);

                                        ahc_setup_initiator_msgout(ahc,
                                                                   &devinfo,
                                                                   scb);
                                } else {
                                        ahc->msg_type =
                                            MSG_TYPE_INITIATOR_MSGIN;
                                        ahc->msgin_index = 0;
                                }
                        }
#ifdef AHC_TARGET_MODE
                        else {
                                if (bus_phase == P_MESGOUT) {
                                        ahc->msg_type =
                                            MSG_TYPE_TARGET_MSGOUT;
                                        ahc->msgin_index = 0;
                                }
                                else 
                                        ahc_setup_target_msgin(ahc,
                                                               &devinfo,
                                                               scb);
                        }
#endif
                }

                ahc_handle_message_phase(ahc);
                break;
        }
        case PERR_DETECTED:
        {
                /*
                 * If we've cleared the parity error interrupt
                 * but the sequencer still believes that SCSIPERR
                 * is true, it must be that the parity error is
                 * for the currently presented byte on the bus,
                 * and we are not in a phase (data-in) where we will
                 * eventually ack this byte.  Ack the byte and
                 * throw it away in the hope that the target will
                 * take us to message out to deliver the appropriate
                 * error message.
                 */
                if ((intstat & SCSIINT) == 0
                 && (ahc_inb(ahc, SSTAT1) & SCSIPERR) != 0) {

                        if ((ahc->features & AHC_DT) == 0) {
                                u_int curphase;

                                /*
                                 * The hardware will only let you ack bytes
                                 * if the expected phase in SCSISIGO matches
                                 * the current phase.  Make sure this is
                                 * currently the case.
                                 */
                                curphase = ahc_inb(ahc, SCSISIGI) & PHASE_MASK;
                                ahc_outb(ahc, LASTPHASE, curphase);
                                ahc_outb(ahc, SCSISIGO, curphase);
                        }
                        if ((ahc_inb(ahc, SCSISIGI) & (CDI|MSGI)) == 0) {
                                int wait;

                                /*
                                 * In a data phase.  Faster to bitbucket
                                 * the data than to individually ack each
                                 * byte.  This is also the only strategy
                                 * that will work with AUTOACK enabled.
                                 */
                                ahc_outb(ahc, SXFRCTL1,
                                         ahc_inb(ahc, SXFRCTL1) | BITBUCKET);
                                wait = 5000;
                                while (--wait != 0) {
                                        if ((ahc_inb(ahc, SCSISIGI)
                                          & (CDI|MSGI)) != 0)
                                                break;
                                        ahc_delay(100);
                                }
                                ahc_outb(ahc, SXFRCTL1,
                                         ahc_inb(ahc, SXFRCTL1) & ~BITBUCKET);
                                if (wait == 0) {
                                        struct        scb *scb;
                                        u_int        scb_index;

                                        ahc_print_devinfo(ahc, &devinfo);
                                        printf("Unable to clear parity error.  "
                                               "Resetting bus.\n");
                                        scb_index = ahc_inb(ahc, SCB_TAG);
                                        scb = ahc_lookup_scb(ahc, scb_index);
                                        if (scb != NULL)
                                                ahc_set_transaction_status(scb,
                                                    CAM_UNCOR_PARITY);
                                        ahc_reset_channel(ahc, devinfo.channel, 
                                                          /*init reset*/TRUE);
                                }
                        } else {
                                ahc_inb(ahc, SCSIDATL);
                        }
                }
                break;
        }
        case DATA_OVERRUN:
        {
                /*
                 * When the sequencer detects an overrun, it
                 * places the controller in "BITBUCKET" mode
                 * and allows the target to complete its transfer.
                 * Unfortunately, none of the counters get updated
                 * when the controller is in this mode, so we have
                 * no way of knowing how large the overrun was.
                 */
                u_int scbindex = ahc_inb(ahc, SCB_TAG);
                u_int lastphase = ahc_inb(ahc, LASTPHASE);
                u_int i;

                scb = ahc_lookup_scb(ahc, scbindex);
                for (i = 0; i < num_phases; i++) {
                        if (lastphase == ahc_phase_table[i].phase)
                                break;
                }
                ahc_print_path(ahc, scb);
                printf("data overrun detected %s."
                       "  Tag == 0x%x.\n",
                       ahc_phase_table[i].phasemsg,
                         scb->hscb->tag);
                ahc_print_path(ahc, scb);
                printf("%s seen Data Phase.  Length = %ld.  NumSGs = %d.\n",
                       ahc_inb(ahc, SEQ_FLAGS) & DPHASE ? "Have" : "Haven't",
                       ahc_get_transfer_length(scb), scb->sg_count);
                if (scb->sg_count > 0) {
                        for (i = 0; i < scb->sg_count; i++) {

                                printf("sg[%d] - Addr 0x%x%x : Length %d\n",
                                       i,
                                       (ahc_le32toh(scb->sg_list[i].len) >> 24
                                        & SG_HIGH_ADDR_BITS),
                                       ahc_le32toh(scb->sg_list[i].addr),
                                       ahc_le32toh(scb->sg_list[i].len)
                                       & AHC_SG_LEN_MASK);
                        }
                }
                /*
                 * Set this and it will take effect when the
                 * target does a command complete.
                 */
                ahc_freeze_devq(ahc, scb);
                if ((scb->flags & SCB_SENSE) == 0) {
                        ahc_set_transaction_status(scb, CAM_DATA_RUN_ERR);
                } else {
                        scb->flags &= ~SCB_SENSE;
                        ahc_set_transaction_status(scb, CAM_AUTOSENSE_FAIL);
                }
                ahc_freeze_scb(scb);

                if ((ahc->features & AHC_ULTRA2) != 0) {
                        /*
                         * Clear the channel in case we return
                         * to data phase later.
                         */
                        ahc_outb(ahc, SXFRCTL0,
                                 ahc_inb(ahc, SXFRCTL0) | CLRSTCNT|CLRCHN);
                        ahc_outb(ahc, SXFRCTL0,
                                 ahc_inb(ahc, SXFRCTL0) | CLRSTCNT|CLRCHN);
                }
                if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
                        u_int dscommand1;

                        /* Ensure HHADDR is 0 for future DMA operations. */
                        dscommand1 = ahc_inb(ahc, DSCOMMAND1);
                        ahc_outb(ahc, DSCOMMAND1, dscommand1 | HADDLDSEL0);
                        ahc_outb(ahc, HADDR, 0);
                        ahc_outb(ahc, DSCOMMAND1, dscommand1);
                }
                break;
        }
        case MKMSG_FAILED:
        {
                u_int scbindex;

                printf("%s:%c:%d:%d: Attempt to issue message failed\n",
                       ahc_name(ahc), devinfo.channel, devinfo.target,
                       devinfo.lun);
                scbindex = ahc_inb(ahc, SCB_TAG);
                scb = ahc_lookup_scb(ahc, scbindex);
                if (scb != NULL
                 && (scb->flags & SCB_RECOVERY_SCB) != 0)
                        /*
                         * Ensure that we didn't put a second instance of this
                         * SCB into the QINFIFO.
                         */
                        ahc_search_qinfifo(ahc, SCB_GET_TARGET(ahc, scb),
                                           SCB_GET_CHANNEL(ahc, scb),
                                           SCB_GET_LUN(scb), scb->hscb->tag,
                                           ROLE_INITIATOR, /*status*/0,
                                           SEARCH_REMOVE);
                break;
        }
        case NO_FREE_SCB:
        {
                printf("%s: No free or disconnected SCBs\n", ahc_name(ahc));
                ahc_dump_card_state(ahc);
                panic("for safety");
                break;
        }
        case SCB_MISMATCH:
        {
                u_int scbptr;

                scbptr = ahc_inb(ahc, SCBPTR);
                printf("Bogus TAG after DMA.  SCBPTR %d, tag %d, our tag %d\n",
                       scbptr, ahc_inb(ahc, ARG_1),
                       ahc->scb_data->hscbs[scbptr].tag);
                ahc_dump_card_state(ahc);
                panic("for saftey");
                break;
        }
        case OUT_OF_RANGE:
        {
                printf("%s: BTT calculation out of range\n", ahc_name(ahc));
                printf("SAVED_SCSIID == 0x%x, SAVED_LUN == 0x%x, "
                       "ARG_1 == 0x%x ACCUM = 0x%x\n",
                       ahc_inb(ahc, SAVED_SCSIID), ahc_inb(ahc, SAVED_LUN),
                       ahc_inb(ahc, ARG_1), ahc_inb(ahc, ACCUM));
                printf("SEQ_FLAGS == 0x%x, SCBPTR == 0x%x, BTT == 0x%x, "
                       "SINDEX == 0x%x\n, A == 0x%x\n",
                       ahc_inb(ahc, SEQ_FLAGS), ahc_inb(ahc, SCBPTR),
                       ahc_index_busy_tcl(ahc,
                            BUILD_TCL(ahc_inb(ahc, SAVED_SCSIID),
                                      ahc_inb(ahc, SAVED_LUN))),
                       ahc_inb(ahc, SINDEX),
                       ahc_inb(ahc, ACCUM));
                printf("SCSIID == 0x%x, SCB_SCSIID == 0x%x, SCB_LUN == 0x%x, "
                       "SCB_TAG == 0x%x, SCB_CONTROL == 0x%x\n",
                       ahc_inb(ahc, SCSIID), ahc_inb(ahc, SCB_SCSIID),
                       ahc_inb(ahc, SCB_LUN), ahc_inb(ahc, SCB_TAG),
                       ahc_inb(ahc, SCB_CONTROL));
                printf("SCSIBUSL == 0x%x, SCSISIGI == 0x%x\n",
                       ahc_inb(ahc, SCSIBUSL), ahc_inb(ahc, SCSISIGI));
                ahc_dump_card_state(ahc);
                panic("for safety");
                break;
        }
        default:
                printf("ahc_intr: seqint, "
                       "intstat == 0x%x, scsisigi = 0x%x\n",
                       intstat, ahc_inb(ahc, SCSISIGI));
                break;
        }
unpause:
        /*
         *  The sequencer is paused immediately on
         *  a SEQINT, so we should restart it when
         *  we're done.
         */
        ahc_unpause(ahc);
}

static void
ahc_handle_scsiint(struct ahc_softc *ahc, u_int intstat)
{
        u_int        scb_index;
        u_int        status0;
        u_int        status;
        struct        scb *scb;
        char        cur_channel;
        char        intr_channel;

        if ((ahc->features & AHC_TWIN) != 0
         && ((ahc_inb(ahc, SBLKCTL) & SELBUSB) != 0))
                cur_channel = 'B';
        else
                cur_channel = 'A';
        intr_channel = cur_channel;

        if ((ahc->features & AHC_ULTRA2) != 0)
                status0 = ahc_inb(ahc, SSTAT0) & IOERR;
        else
                status0 = 0;
        status = ahc_inb(ahc, SSTAT1) & (SELTO|SCSIRSTI|BUSFREE|SCSIPERR);
        if (status == 0 && status0 == 0) {
                if ((ahc->features & AHC_TWIN) != 0) {
                        /* Try the other channel */
                         ahc_outb(ahc, SBLKCTL, ahc_inb(ahc, SBLKCTL) ^ SELBUSB);
                        status = ahc_inb(ahc, SSTAT1)
                               & (SELTO|SCSIRSTI|BUSFREE|SCSIPERR);
                        intr_channel = (cur_channel == 'A') ? 'B' : 'A';
                }
                if (status == 0) {
                        printf("%s: Spurious SCSI interrupt\n", ahc_name(ahc));
                        ahc_outb(ahc, CLRINT, CLRSCSIINT);
                        ahc_unpause(ahc);
                        return;
                }
        }

        /* Make sure the sequencer is in a safe location. */
        ahc_clear_critical_section(ahc);

        scb_index = ahc_inb(ahc, SCB_TAG);
        scb = ahc_lookup_scb(ahc, scb_index);
        if (scb != NULL
         && (ahc_inb(ahc, SEQ_FLAGS) & NOT_IDENTIFIED) != 0)
                scb = NULL;

        if ((ahc->features & AHC_ULTRA2) != 0
         && (status0 & IOERR) != 0) {
                int now_lvd;

                now_lvd = ahc_inb(ahc, SBLKCTL) & ENAB40;
                printf("%s: Transceiver State Has Changed to %s mode\n",
                       ahc_name(ahc), now_lvd ? "LVD" : "SE");
                ahc_outb(ahc, CLRSINT0, CLRIOERR);
                /*
                 * When transitioning to SE mode, the reset line
                 * glitches, triggering an arbitration bug in some
                 * Ultra2 controllers.  This bug is cleared when we
                 * assert the reset line.  Since a reset glitch has
                 * already occurred with this transition and a
                 * transceiver state change is handled just like
                 * a bus reset anyway, asserting the reset line
                 * ourselves is safe.
                 */
                ahc_reset_channel(ahc, intr_channel,
                                 /*Initiate Reset*/now_lvd == 0);
        } else if ((status & SCSIRSTI) != 0) {
                printf("%s: Someone reset channel %c\n",
                        ahc_name(ahc), intr_channel);
                if (intr_channel != cur_channel)
                         ahc_outb(ahc, SBLKCTL, ahc_inb(ahc, SBLKCTL) ^ SELBUSB);
                ahc_reset_channel(ahc, intr_channel, /*Initiate Reset*/FALSE);
        } else if ((status & SCSIPERR) != 0) {
                /*
                 * Determine the bus phase and queue an appropriate message.
                 * SCSIPERR is latched true as soon as a parity error
                 * occurs.  If the sequencer acked the transfer that
                 * caused the parity error and the currently presented
                 * transfer on the bus has correct parity, SCSIPERR will
                 * be cleared by CLRSCSIPERR.  Use this to determine if
                 * we should look at the last phase the sequencer recorded,
                 * or the current phase presented on the bus.
                 */
                struct        ahc_devinfo devinfo;
                u_int        mesg_out;
                u_int        curphase;
                u_int        errorphase;
                u_int        lastphase;
                u_int        scsirate;
                u_int        i;
                u_int        sstat2;
                int        silent;

                lastphase = ahc_inb(ahc, LASTPHASE);
                curphase = ahc_inb(ahc, SCSISIGI) & PHASE_MASK;
                sstat2 = ahc_inb(ahc, SSTAT2);
                ahc_outb(ahc, CLRSINT1, CLRSCSIPERR);
                /*
                 * For all phases save DATA, the sequencer won't
                 * automatically ack a byte that has a parity error
                 * in it.  So the only way that the current phase
                 * could be 'data-in' is if the parity error is for
                 * an already acked byte in the data phase.  During
                 * synchronous data-in transfers, we may actually
                 * ack bytes before latching the current phase in
                 * LASTPHASE, leading to the discrepancy between
                 * curphase and lastphase.
                 */
                if ((ahc_inb(ahc, SSTAT1) & SCSIPERR) != 0
                 || curphase == P_DATAIN || curphase == P_DATAIN_DT)
                        errorphase = curphase;
                else
                        errorphase = lastphase;

                for (i = 0; i < num_phases; i++) {
                        if (errorphase == ahc_phase_table[i].phase)
                                break;
                }
                mesg_out = ahc_phase_table[i].mesg_out;
                silent = FALSE;
                if (scb != NULL) {
                        if (SCB_IS_SILENT(scb))
                                silent = TRUE;
                        else
                                ahc_print_path(ahc, scb);
                        scb->flags |= SCB_TRANSMISSION_ERROR;
                } else
                        printf("%s:%c:%d: ", ahc_name(ahc), intr_channel,
                               SCSIID_TARGET(ahc, ahc_inb(ahc, SAVED_SCSIID)));
                scsirate = ahc_inb(ahc, SCSIRATE);
                if (silent == FALSE) {
                        printf("parity error detected %s. "
                               "SEQADDR(0x%x) SCSIRATE(0x%x)\n",
                               ahc_phase_table[i].phasemsg,
                               ahc_inw(ahc, SEQADDR0),
                               scsirate);
                        if ((ahc->features & AHC_DT) != 0) {
                                if ((sstat2 & CRCVALERR) != 0)
                                        printf("\tCRC Value Mismatch\n");
                                if ((sstat2 & CRCENDERR) != 0)
                                        printf("\tNo terminal CRC packet "
                                               "recevied\n");
                                if ((sstat2 & CRCREQERR) != 0)
                                        printf("\tIllegal CRC packet "
                                               "request\n");
                                if ((sstat2 & DUAL_EDGE_ERR) != 0)
                                        printf("\tUnexpected %sDT Data Phase\n",
                                               (scsirate & SINGLE_EDGE)
                                             ? "" : "non-");
                        }
                }

                if ((ahc->features & AHC_DT) != 0
                 && (sstat2 & DUAL_EDGE_ERR) != 0) {
                        /*
                         * This error applies regardless of
                         * data direction, so ignore the value
                         * in the phase table.
                         */
                        mesg_out = MSG_INITIATOR_DET_ERR;
                }

                /*
                 * We've set the hardware to assert ATN if we   
                 * get a parity error on "in" phases, so all we  
                 * need to do is stuff the message buffer with
                 * the appropriate message.  "In" phases have set
                 * mesg_out to something other than MSG_NOP.
                 */
                if (mesg_out != MSG_NOOP) {
                        if (ahc->msg_type != MSG_TYPE_NONE)
                                ahc->send_msg_perror = TRUE;
                        else
                                ahc_outb(ahc, MSG_OUT, mesg_out);
                }
                /*
                 * Force a renegotiation with this target just in
                 * case we are out of sync for some external reason
                 * unknown (or unreported) by the target.
                 */
                ahc_fetch_devinfo(ahc, &devinfo);
                ahc_force_renegotiation(ahc, &devinfo);

                ahc_outb(ahc, CLRINT, CLRSCSIINT);
                ahc_unpause(ahc);
        } else if ((status & SELTO) != 0) {
                u_int        scbptr;

                /* Stop the selection */
                ahc_outb(ahc, SCSISEQ, 0);

                /* No more pending messages */
                ahc_clear_msg_state(ahc);

                /* Clear interrupt state */
                ahc_outb(ahc, SIMODE1, ahc_inb(ahc, SIMODE1) & ~ENBUSFREE);
                ahc_outb(ahc, CLRSINT1, CLRSELTIMEO|CLRBUSFREE|CLRSCSIPERR);

                /*
                 * Although the driver does not care about the
                 * 'Selection in Progress' status bit, the busy
                 * LED does.  SELINGO is only cleared by a sucessfull
                 * selection, so we must manually clear it to insure
                 * the LED turns off just incase no future successful
                 * selections occur (e.g. no devices on the bus).
                 */
                ahc_outb(ahc, CLRSINT0, CLRSELINGO);

                scbptr = ahc_inb(ahc, WAITING_SCBH);
                ahc_outb(ahc, SCBPTR, scbptr);
                scb_index = ahc_inb(ahc, SCB_TAG);

                scb = ahc_lookup_scb(ahc, scb_index);
                if (scb == NULL) {
                        printf("%s: ahc_intr - referenced scb not "
                               "valid during SELTO scb(%d, %d)\n",
                               ahc_name(ahc), scbptr, scb_index);
                        ahc_dump_card_state(ahc);
                } else {
                        struct ahc_devinfo devinfo;
#ifdef AHC_DEBUG
                        if ((ahc_debug & AHC_SHOW_SELTO) != 0) {
                                ahc_print_path(ahc, scb);
                                printf("Saw Selection Timeout for SCB 0x%x\n",
                                       scb_index);
                        }
#endif
                        ahc_scb_devinfo(ahc, &devinfo, scb);
                        ahc_set_transaction_status(scb, CAM_SEL_TIMEOUT);
                        ahc_freeze_devq(ahc, scb);

                        /*
                         * Cancel any pending transactions on the device
                         * now that it seems to be missing.  This will
                         * also revert us to async/narrow transfers until
                         * we can renegotiate with the device.
                         */
                        ahc_handle_devreset(ahc, &devinfo,
                                            CAM_SEL_TIMEOUT,
                                            "Selection Timeout",
                                            /*verbose_level*/1);
                }
                ahc_outb(ahc, CLRINT, CLRSCSIINT);
                ahc_restart(ahc);
        } else if ((status & BUSFREE) != 0
                && (ahc_inb(ahc, SIMODE1) & ENBUSFREE) != 0) {
                struct        ahc_devinfo devinfo;
                u_int        lastphase;
                u_int        saved_scsiid;
                u_int        saved_lun;
                u_int        target;
                u_int        initiator_role_id;
                char        channel;
                int        printerror;

                /*
                 * Clear our selection hardware as soon as possible.
                 * We may have an entry in the waiting Q for this target,
                 * that is affected by this busfree and we don't want to
                 * go about selecting the target while we handle the event.
                 */
                ahc_outb(ahc, SCSISEQ,
                         ahc_inb(ahc, SCSISEQ) & (ENSELI|ENRSELI|ENAUTOATNP));

                /*
                 * Disable busfree interrupts and clear the busfree
                 * interrupt status.  We do this here so that several
                 * bus transactions occur prior to clearing the SCSIINT
                 * latch.  It can take a bit for the clearing to take effect.
                 */
                ahc_outb(ahc, SIMODE1, ahc_inb(ahc, SIMODE1) & ~ENBUSFREE);
                ahc_outb(ahc, CLRSINT1, CLRBUSFREE|CLRSCSIPERR);

                /*
                 * Look at what phase we were last in.
                 * If its message out, chances are pretty good
                 * that the busfree was in response to one of
                 * our abort requests.
                 */
                lastphase = ahc_inb(ahc, LASTPHASE);
                saved_scsiid = ahc_inb(ahc, SAVED_SCSIID);
                saved_lun = ahc_inb(ahc, SAVED_LUN);
                target = SCSIID_TARGET(ahc, saved_scsiid);
                initiator_role_id = SCSIID_OUR_ID(saved_scsiid);
                channel = SCSIID_CHANNEL(ahc, saved_scsiid);
                ahc_compile_devinfo(&devinfo, initiator_role_id,
                                    target, saved_lun, channel, ROLE_INITIATOR);
                printerror = 1;

                if (lastphase == P_MESGOUT) {
                        u_int tag;

                        tag = SCB_LIST_NULL;
                        if (ahc_sent_msg(ahc, AHCMSG_1B, MSG_ABORT_TAG, TRUE)
                         || ahc_sent_msg(ahc, AHCMSG_1B, MSG_ABORT, TRUE)) {
                                if (ahc->msgout_buf[ahc->msgout_index - 1]
                                 == MSG_ABORT_TAG)
                                        tag = scb->hscb->tag;
                                ahc_print_path(ahc, scb);
                                printf("SCB %d - Abort%s Completed.\n",
                                       scb->hscb->tag, tag == SCB_LIST_NULL ?
                                       "" : " Tag");
                                ahc_abort_scbs(ahc, target, channel,
                                               saved_lun, tag,
                                               ROLE_INITIATOR,
                                               CAM_REQ_ABORTED);
                                printerror = 0;
                        } else if (ahc_sent_msg(ahc, AHCMSG_1B,
                                                MSG_BUS_DEV_RESET, TRUE)) {
#ifdef __FreeBSD__
                                /*
                                 * Don't mark the user's request for this BDR
                                 * as completing with CAM_BDR_SENT.  CAM3
                                 * specifies CAM_REQ_CMP.
                                 */
                                if (scb != NULL
                                 && scb->io_ctx->ccb_h.func_code== XPT_RESET_DEV
                                 && ahc_match_scb(ahc, scb, target, channel,
                                                  CAM_LUN_WILDCARD,
                                                  SCB_LIST_NULL,
                                                  ROLE_INITIATOR)) {
                                        ahc_set_transaction_status(scb, CAM_REQ_CMP);
                                }
#endif
                                ahc_compile_devinfo(&devinfo,
                                                    initiator_role_id,
                                                    target,
                                                    CAM_LUN_WILDCARD,
                                                    channel,
                                                    ROLE_INITIATOR);
                                ahc_handle_devreset(ahc, &devinfo,
                                                    CAM_BDR_SENT,
                                                    "Bus Device Reset",
                                                    /*verbose_level*/0);
                                printerror = 0;
                        } else if (ahc_sent_msg(ahc, AHCMSG_EXT,
                                                MSG_EXT_PPR, FALSE)) {
                                struct ahc_initiator_tinfo *tinfo;
                                struct ahc_tmode_tstate *tstate;

                                /*
                                 * PPR Rejected.  Try non-ppr negotiation
                                 * and retry command.
                                 */
                                tinfo = ahc_fetch_transinfo(ahc,
                                                            devinfo.channel,
                                                            devinfo.our_scsiid,
                                                            devinfo.target,
                                                            &tstate);
                                tinfo->curr.transport_version = 2;
                                tinfo->goal.transport_version = 2;
                                tinfo->goal.ppr_options = 0;
                                ahc_qinfifo_requeue_tail(ahc, scb);
                                printerror = 0;
                        } else if (ahc_sent_msg(ahc, AHCMSG_EXT,
                                                MSG_EXT_WDTR, FALSE)) {
                                /*
                                 * Negotiation Rejected.  Go-narrow and
                                 * retry command.
                                 */
                                ahc_set_width(ahc, &devinfo,
                                              MSG_EXT_WDTR_BUS_8_BIT,
                                              AHC_TRANS_CUR|AHC_TRANS_GOAL,
                                              /*paused*/TRUE);
                                ahc_qinfifo_requeue_tail(ahc, scb);
                                printerror = 0;
                        } else if (ahc_sent_msg(ahc, AHCMSG_EXT,
                                                MSG_EXT_SDTR, FALSE)) {
                                /*
                                 * Negotiation Rejected.  Go-async and
                                 * retry command.
                                 */
                                ahc_set_syncrate(ahc, &devinfo,
                                                /*syncrate*/NULL,
                                                /*period*/0, /*offset*/0,
                                                /*ppr_options*/0,
                                                AHC_TRANS_CUR|AHC_TRANS_GOAL,
                                                /*paused*/TRUE);
                                ahc_qinfifo_requeue_tail(ahc, scb);
                                printerror = 0;
                        }
                }
                if (printerror != 0) {
                        u_int i;

                        if (scb != NULL) {
                                u_int tag;

                                if ((scb->hscb->control & TAG_ENB) != 0)
                                        tag = scb->hscb->tag;
                                else
                                        tag = SCB_LIST_NULL;
                                ahc_print_path(ahc, scb);
                                ahc_abort_scbs(ahc, target, channel,
                                               SCB_GET_LUN(scb), tag,
                                               ROLE_INITIATOR,
                                               CAM_UNEXP_BUSFREE);
                        } else {
                                /*
                                 * We had not fully identified this connection,
                                 * so we cannot abort anything.
                                 */
                                printf("%s: ", ahc_name(ahc));
                        }
                        for (i = 0; i < num_phases; i++) {
                                if (lastphase == ahc_phase_table[i].phase)
                                        break;
                        }
                        if (lastphase != P_BUSFREE) {
                                /*
                                 * Renegotiate with this device at the
                                 * next oportunity just in case this busfree
                                 * is due to a negotiation mismatch with the
                                 * device.
                                 */
                                ahc_force_renegotiation(ahc, &devinfo);
                        }
                        printf("Unexpected busfree %s\n"
                               "SEQADDR == 0x%x\n",
                               ahc_phase_table[i].phasemsg,
                               ahc_inb(ahc, SEQADDR0)
                                | (ahc_inb(ahc, SEQADDR1) << 8));
                }
                ahc_outb(ahc, CLRINT, CLRSCSIINT);
                ahc_restart(ahc);
        } else {
                printf("%s: Missing case in ahc_handle_scsiint. status = %x\n",
                       ahc_name(ahc), status);
                ahc_outb(ahc, CLRINT, CLRSCSIINT);
        }
}

/*
 * Force renegotiation to occur the next time we initiate
 * a command to the current device.
 */
static void
ahc_force_renegotiation(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        struct        ahc_initiator_tinfo *targ_info;
        struct        ahc_tmode_tstate *tstate;

        targ_info = ahc_fetch_transinfo(ahc,
                                        devinfo->channel,
                                        devinfo->our_scsiid,
                                        devinfo->target,
                                        &tstate);
        ahc_update_neg_request(ahc, devinfo, tstate,
                               targ_info, AHC_NEG_IF_NON_ASYNC);
}

#define AHC_MAX_STEPS 2000
static void
ahc_clear_critical_section(struct ahc_softc *ahc)
{
        int        stepping;
        int        steps;
        u_int        simode0;
        u_int        simode1;

        if (ahc->num_critical_sections == 0)
                return;

        stepping = FALSE;
        steps = 0;
        simode0 = 0;
        simode1 = 0;
        for (;;) {
                struct        cs *cs;
                u_int        seqaddr;
                u_int        i;

                seqaddr = ahc_inb(ahc, SEQADDR0)
                        | (ahc_inb(ahc, SEQADDR1) << 8);

                /*
                 * Seqaddr represents the next instruction to execute, 
                 * so we are really executing the instruction just
                 * before it.
                 */
                if (seqaddr != 0)
                        seqaddr -= 1;
                cs = ahc->critical_sections;
                for (i = 0; i < ahc->num_critical_sections; i++, cs++) {
                        
                        if (cs->begin < seqaddr && cs->end >= seqaddr)
                                break;
                }

                if (i == ahc->num_critical_sections)
                        break;

                if (steps > AHC_MAX_STEPS) {
                        printf("%s: Infinite loop in critical section\n",
                               ahc_name(ahc));
                        ahc_dump_card_state(ahc);
                        panic("critical section loop");
                }

                steps++;
                if (stepping == FALSE) {

                        /*
                         * Disable all interrupt sources so that the
                         * sequencer will not be stuck by a pausing
                         * interrupt condition while we attempt to
                         * leave a critical section.
                         */
                        simode0 = ahc_inb(ahc, SIMODE0);
                        ahc_outb(ahc, SIMODE0, 0);
                        simode1 = ahc_inb(ahc, SIMODE1);
                        if ((ahc->features & AHC_DT) != 0)
                                /*
                                 * On DT class controllers, we
                                 * use the enhanced busfree logic.
                                 * Unfortunately we cannot re-enable
                                 * busfree detection within the
                                 * current connection, so we must
                                 * leave it on while single stepping.
                                 */
                                ahc_outb(ahc, SIMODE1, simode1 & ENBUSFREE);
                        else
                                ahc_outb(ahc, SIMODE1, 0);
                        ahc_outb(ahc, CLRINT, CLRSCSIINT);
                        ahc_outb(ahc, SEQCTL, ahc->seqctl | STEP);
                        stepping = TRUE;
                }
                if ((ahc->features & AHC_DT) != 0) {
                        ahc_outb(ahc, CLRSINT1, CLRBUSFREE);
                        ahc_outb(ahc, CLRINT, CLRSCSIINT);
                }
                ahc_outb(ahc, HCNTRL, ahc->unpause);
                while (!ahc_is_paused(ahc))
                        ahc_delay(200);
        }
        if (stepping) {
                ahc_outb(ahc, SIMODE0, simode0);
                ahc_outb(ahc, SIMODE1, simode1);
                ahc_outb(ahc, SEQCTL, ahc->seqctl);
        }
}

/*
 * Clear any pending interrupt status.
 */
static void
ahc_clear_intstat(struct ahc_softc *ahc)
{
        /* Clear any interrupt conditions this may have caused */
        ahc_outb(ahc, CLRSINT1, CLRSELTIMEO|CLRATNO|CLRSCSIRSTI
                                |CLRBUSFREE|CLRSCSIPERR|CLRPHASECHG|
                                CLRREQINIT);
        ahc_flush_device_writes(ahc);
        ahc_outb(ahc, CLRSINT0, CLRSELDO|CLRSELDI|CLRSELINGO);
         ahc_flush_device_writes(ahc);
        ahc_outb(ahc, CLRINT, CLRSCSIINT);
        ahc_flush_device_writes(ahc);
}

/**************************** Debugging Routines ******************************/
#ifdef AHC_DEBUG
uint32_t ahc_debug = AHC_DEBUG_OPTS;
#endif

#if 0 /* unused */
static void
ahc_print_scb(struct scb *scb)
{
        int i;

        struct hardware_scb *hscb = scb->hscb;

        printf("scb:%p control:0x%x scsiid:0x%x lun:%d cdb_len:%d\n",
               (void *)scb,
               hscb->control,
               hscb->scsiid,
               hscb->lun,
               hscb->cdb_len);
        printf("Shared Data: ");
        for (i = 0; i < sizeof(hscb->shared_data.cdb); i++)
                printf("%#02x", hscb->shared_data.cdb[i]);
        printf("        dataptr:%#x datacnt:%#x sgptr:%#x tag:%#x\n",
                ahc_le32toh(hscb->dataptr),
                ahc_le32toh(hscb->datacnt),
                ahc_le32toh(hscb->sgptr),
                hscb->tag);
        if (scb->sg_count > 0) {
                for (i = 0; i < scb->sg_count; i++) {
                        printf("sg[%d] - Addr 0x%x%x : Length %d\n",
                               i,
                               (ahc_le32toh(scb->sg_list[i].len) >> 24
                                & SG_HIGH_ADDR_BITS),
                               ahc_le32toh(scb->sg_list[i].addr),
                               ahc_le32toh(scb->sg_list[i].len));
                }
        }
}
#endif

/************************* Transfer Negotiation *******************************/
/*
 * Allocate per target mode instance (ID we respond to as a target)
 * transfer negotiation data structures.
 */
static struct ahc_tmode_tstate *
ahc_alloc_tstate(struct ahc_softc *ahc, u_int scsi_id, char channel)
{
        struct ahc_tmode_tstate *master_tstate;
        struct ahc_tmode_tstate *tstate;
        int i;

        master_tstate = ahc->enabled_targets[ahc->our_id];
        if (channel == 'B') {
                scsi_id += 8;
                master_tstate = ahc->enabled_targets[ahc->our_id_b + 8];
        }
        if (ahc->enabled_targets[scsi_id] != NULL
         && ahc->enabled_targets[scsi_id] != master_tstate)
                panic("%s: ahc_alloc_tstate - Target already allocated",
                      ahc_name(ahc));
        tstate = (struct ahc_tmode_tstate*)malloc(sizeof(*tstate),
                                                   M_DEVBUF, M_NOWAIT);
        if (tstate == NULL)
                return (NULL);

        /*
         * If we have allocated a master tstate, copy user settings from
         * the master tstate (taken from SRAM or the EEPROM) for this
         * channel, but reset our current and goal settings to async/narrow
         * until an initiator talks to us.
         */
        if (master_tstate != NULL) {
                memcpy(tstate, master_tstate, sizeof(*tstate));
                memset(tstate->enabled_luns, 0, sizeof(tstate->enabled_luns));
                tstate->ultraenb = 0;
                for (i = 0; i < AHC_NUM_TARGETS; i++) {
                        memset(&tstate->transinfo[i].curr, 0,
                              sizeof(tstate->transinfo[i].curr));
                        memset(&tstate->transinfo[i].goal, 0,
                              sizeof(tstate->transinfo[i].goal));
                }
        } else
                memset(tstate, 0, sizeof(*tstate));
        ahc->enabled_targets[scsi_id] = tstate;
        return (tstate);
}

#ifdef AHC_TARGET_MODE
/*
 * Free per target mode instance (ID we respond to as a target)
 * transfer negotiation data structures.
 */
static void
ahc_free_tstate(struct ahc_softc *ahc, u_int scsi_id, char channel, int force)
{
        struct ahc_tmode_tstate *tstate;

        /*
         * Don't clean up our "master" tstate.
         * It has our default user settings.
         */
        if (((channel == 'B' && scsi_id == ahc->our_id_b)
          || (channel == 'A' && scsi_id == ahc->our_id))
         && force == FALSE)
                return;

        if (channel == 'B')
                scsi_id += 8;
        tstate = ahc->enabled_targets[scsi_id];
        if (tstate != NULL)
                free(tstate, M_DEVBUF);
        ahc->enabled_targets[scsi_id] = NULL;
}
#endif

/*
 * Called when we have an active connection to a target on the bus,
 * this function finds the nearest syncrate to the input period limited
 * by the capabilities of the bus connectivity of and sync settings for
 * the target.
 */
const struct ahc_syncrate *
ahc_devlimited_syncrate(struct ahc_softc *ahc,
                        struct ahc_initiator_tinfo *tinfo,
                        u_int *period, u_int *ppr_options, role_t role)
{
        struct        ahc_transinfo *transinfo;
        u_int        maxsync;

        if ((ahc->features & AHC_ULTRA2) != 0) {
                if ((ahc_inb(ahc, SBLKCTL) & ENAB40) != 0
                 && (ahc_inb(ahc, SSTAT2) & EXP_ACTIVE) == 0) {
                        maxsync = AHC_SYNCRATE_DT;
                } else {
                        maxsync = AHC_SYNCRATE_ULTRA;
                        /* Can't do DT on an SE bus */
                        *ppr_options &= ~MSG_EXT_PPR_DT_REQ;
                }
        } else if ((ahc->features & AHC_ULTRA) != 0) {
                maxsync = AHC_SYNCRATE_ULTRA;
        } else {
                maxsync = AHC_SYNCRATE_FAST;
        }
        /*
         * Never allow a value higher than our current goal
         * period otherwise we may allow a target initiated
         * negotiation to go above the limit as set by the
         * user.  In the case of an initiator initiated
         * sync negotiation, we limit based on the user
         * setting.  This allows the system to still accept
         * incoming negotiations even if target initiated
         * negotiation is not performed.
         */
        if (role == ROLE_TARGET)
                transinfo = &tinfo->user;
        else 
                transinfo = &tinfo->goal;
        *ppr_options &= transinfo->ppr_options;
        if (transinfo->width == MSG_EXT_WDTR_BUS_8_BIT) {
                maxsync = max(maxsync, (u_int)AHC_SYNCRATE_ULTRA2);
                *ppr_options &= ~MSG_EXT_PPR_DT_REQ;
        }
        if (transinfo->period == 0) {
                *period = 0;
                *ppr_options = 0;
                return (NULL);
        }
        *period = max(*period, (u_int)transinfo->period);
        return (ahc_find_syncrate(ahc, period, ppr_options, maxsync));
}

/*
 * Look up the valid period to SCSIRATE conversion in our table.
 * Return the period and offset that should be sent to the target
 * if this was the beginning of an SDTR.
 */
const struct ahc_syncrate *
ahc_find_syncrate(struct ahc_softc *ahc, u_int *period,
                  u_int *ppr_options, u_int maxsync)
{
        const struct ahc_syncrate *syncrate;

        if ((ahc->features & AHC_DT) == 0)
                *ppr_options &= ~MSG_EXT_PPR_DT_REQ;

        /* Skip all DT only entries if DT is not available */
        if ((*ppr_options & MSG_EXT_PPR_DT_REQ) == 0
         && maxsync < AHC_SYNCRATE_ULTRA2)
                maxsync = AHC_SYNCRATE_ULTRA2;

        /* Now set the maxsync based on the card capabilities
         * DT is already done above */
        if ((ahc->features & (AHC_DT | AHC_ULTRA2)) == 0
            && maxsync < AHC_SYNCRATE_ULTRA)
                maxsync = AHC_SYNCRATE_ULTRA;
        if ((ahc->features & (AHC_DT | AHC_ULTRA2 | AHC_ULTRA)) == 0
            && maxsync < AHC_SYNCRATE_FAST)
                maxsync = AHC_SYNCRATE_FAST;

        for (syncrate = &ahc_syncrates[maxsync];
             syncrate->rate != NULL;
             syncrate++) {

                /*
                 * The Ultra2 table doesn't go as low
                 * as for the Fast/Ultra cards.
                 */
                if ((ahc->features & AHC_ULTRA2) != 0
                 && (syncrate->sxfr_u2 == 0))
                        break;

                if (*period <= syncrate->period) {
                        /*
                         * When responding to a target that requests
                         * sync, the requested rate may fall between
                         * two rates that we can output, but still be
                         * a rate that we can receive.  Because of this,
                         * we want to respond to the target with
                         * the same rate that it sent to us even
                         * if the period we use to send data to it
                         * is lower.  Only lower the response period
                         * if we must.
                         */
                        if (syncrate == &ahc_syncrates[maxsync])
                                *period = syncrate->period;

                        /*
                         * At some speeds, we only support
                         * ST transfers.
                         */
                         if ((syncrate->sxfr_u2 & ST_SXFR) != 0)
                                *ppr_options &= ~MSG_EXT_PPR_DT_REQ;
                        break;
                }
        }

        if ((*period == 0)
         || (syncrate->rate == NULL)
         || ((ahc->features & AHC_ULTRA2) != 0
          && (syncrate->sxfr_u2 == 0))) {
                /* Use asynchronous transfers. */
                *period = 0;
                syncrate = NULL;
                *ppr_options &= ~MSG_EXT_PPR_DT_REQ;
        }
        return (syncrate);
}

/*
 * Convert from an entry in our syncrate table to the SCSI equivalent
 * sync "period" factor.
 */
u_int
ahc_find_period(struct ahc_softc *ahc, u_int scsirate, u_int maxsync)
{
        const struct ahc_syncrate *syncrate;

        if ((ahc->features & AHC_ULTRA2) != 0)
                scsirate &= SXFR_ULTRA2;
        else
                scsirate &= SXFR;

        /* now set maxsync based on card capabilities */
        if ((ahc->features & AHC_DT) == 0 && maxsync < AHC_SYNCRATE_ULTRA2)
                maxsync = AHC_SYNCRATE_ULTRA2;
        if ((ahc->features & (AHC_DT | AHC_ULTRA2)) == 0
            && maxsync < AHC_SYNCRATE_ULTRA)
                maxsync = AHC_SYNCRATE_ULTRA;
        if ((ahc->features & (AHC_DT | AHC_ULTRA2 | AHC_ULTRA)) == 0
            && maxsync < AHC_SYNCRATE_FAST)
                maxsync = AHC_SYNCRATE_FAST;


        syncrate = &ahc_syncrates[maxsync];
        while (syncrate->rate != NULL) {

                if ((ahc->features & AHC_ULTRA2) != 0) {
                        if (syncrate->sxfr_u2 == 0)
                                break;
                        else if (scsirate == (syncrate->sxfr_u2 & SXFR_ULTRA2))
                                return (syncrate->period);
                } else if (scsirate == (syncrate->sxfr & SXFR)) {
                                return (syncrate->period);
                }
                syncrate++;
        }
        return (0); /* async */
}

/*
 * Truncate the given synchronous offset to a value the
 * current adapter type and syncrate are capable of.
 */
static void
ahc_validate_offset(struct ahc_softc *ahc,
                    struct ahc_initiator_tinfo *tinfo,
                    const struct ahc_syncrate *syncrate,
                    u_int *offset, int wide, role_t role)
{
        u_int maxoffset;

        /* Limit offset to what we can do */
        if (syncrate == NULL) {
                maxoffset = 0;
        } else if ((ahc->features & AHC_ULTRA2) != 0) {
                maxoffset = MAX_OFFSET_ULTRA2;
        } else {
                if (wide)
                        maxoffset = MAX_OFFSET_16BIT;
                else
                        maxoffset = MAX_OFFSET_8BIT;
        }
        *offset = min(*offset, maxoffset);
        if (tinfo != NULL) {
                if (role == ROLE_TARGET)
                        *offset = min(*offset, (u_int)tinfo->user.offset);
                else
                        *offset = min(*offset, (u_int)tinfo->goal.offset);
        }
}

/*
 * Truncate the given transfer width parameter to a value the
 * current adapter type is capable of.
 */
static void
ahc_validate_width(struct ahc_softc *ahc, struct ahc_initiator_tinfo *tinfo,
                   u_int *bus_width, role_t role)
{
        switch (*bus_width) {
        default:
                if (ahc->features & AHC_WIDE) {
                        /* Respond Wide */
                        *bus_width = MSG_EXT_WDTR_BUS_16_BIT;
                        break;
                }
                /* FALLTHROUGH */
        case MSG_EXT_WDTR_BUS_8_BIT:
                *bus_width = MSG_EXT_WDTR_BUS_8_BIT;
                break;
        }
        if (tinfo != NULL) {
                if (role == ROLE_TARGET)
                        *bus_width = min((u_int)tinfo->user.width, *bus_width);
                else
                        *bus_width = min((u_int)tinfo->goal.width, *bus_width);
        }
}

/*
 * Update the bitmask of targets for which the controller should
 * negotiate with at the next convenient oportunity.  This currently
 * means the next time we send the initial identify messages for
 * a new transaction.
 */
int
ahc_update_neg_request(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                       struct ahc_tmode_tstate *tstate,
                       struct ahc_initiator_tinfo *tinfo, ahc_neg_type neg_type)
{
        u_int auto_negotiate_orig;

        auto_negotiate_orig = tstate->auto_negotiate;
        if (neg_type == AHC_NEG_ALWAYS) {
                /*
                 * Force our "current" settings to be
                 * unknown so that unless a bus reset
                 * occurs the need to renegotiate is
                 * recorded persistently.
                 */
                if ((ahc->features & AHC_WIDE) != 0)
                        tinfo->curr.width = AHC_WIDTH_UNKNOWN;
                tinfo->curr.period = AHC_PERIOD_UNKNOWN;
                tinfo->curr.offset = AHC_OFFSET_UNKNOWN;
        }
        if (tinfo->curr.period != tinfo->goal.period
         || tinfo->curr.width != tinfo->goal.width
         || tinfo->curr.offset != tinfo->goal.offset
         || tinfo->curr.ppr_options != tinfo->goal.ppr_options
         || (neg_type == AHC_NEG_IF_NON_ASYNC
          && (tinfo->goal.offset != 0
           || tinfo->goal.width != MSG_EXT_WDTR_BUS_8_BIT
           || tinfo->goal.ppr_options != 0)))
                tstate->auto_negotiate |= devinfo->target_mask;
        else
                tstate->auto_negotiate &= ~devinfo->target_mask;

        return (auto_negotiate_orig != tstate->auto_negotiate);
}

/*
 * Update the user/goal/curr tables of synchronous negotiation
 * parameters as well as, in the case of a current or active update,
 * any data structures on the host controller.  In the case of an
 * active update, the specified target is currently talking to us on
 * the bus, so the transfer parameter update must take effect
 * immediately.
 */
void
ahc_set_syncrate(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                 const struct ahc_syncrate *syncrate, u_int period,
                 u_int offset, u_int ppr_options, u_int type, int paused)
{
        struct        ahc_initiator_tinfo *tinfo;
        struct        ahc_tmode_tstate *tstate;
        u_int        old_period;
        u_int        old_offset;
        u_int        old_ppr;
        int        active;
        int        update_needed;

        active = (type & AHC_TRANS_ACTIVE) == AHC_TRANS_ACTIVE;
        update_needed = 0;

        if (syncrate == NULL) {
                period = 0;
                offset = 0;
        }

        tinfo = ahc_fetch_transinfo(ahc, devinfo->channel, devinfo->our_scsiid,
                                    devinfo->target, &tstate);

        if ((type & AHC_TRANS_USER) != 0) {
                tinfo->user.period = period;
                tinfo->user.offset = offset;
                tinfo->user.ppr_options = ppr_options;
        }

        if ((type & AHC_TRANS_GOAL) != 0) {
                tinfo->goal.period = period;
                tinfo->goal.offset = offset;
                tinfo->goal.ppr_options = ppr_options;
        }

        old_period = tinfo->curr.period;
        old_offset = tinfo->curr.offset;
        old_ppr           = tinfo->curr.ppr_options;

        if ((type & AHC_TRANS_CUR) != 0
         && (old_period != period
          || old_offset != offset
          || old_ppr != ppr_options)) {
                u_int        scsirate;

                update_needed++;
                scsirate = tinfo->scsirate;
                if ((ahc->features & AHC_ULTRA2) != 0) {

                        scsirate &= ~(SXFR_ULTRA2|SINGLE_EDGE|ENABLE_CRC);
                        if (syncrate != NULL) {
                                scsirate |= syncrate->sxfr_u2;
                                if ((ppr_options & MSG_EXT_PPR_DT_REQ) != 0)
                                        scsirate |= ENABLE_CRC;
                                else
                                        scsirate |= SINGLE_EDGE;
                        }
                } else {

                        scsirate &= ~(SXFR|SOFS);
                        /*
                         * Ensure Ultra mode is set properly for
                         * this target.
                         */
                        tstate->ultraenb &= ~devinfo->target_mask;
                        if (syncrate != NULL) {
                                if (syncrate->sxfr & ULTRA_SXFR) {
                                        tstate->ultraenb |=
                                                devinfo->target_mask;
                                }
                                scsirate |= syncrate->sxfr & SXFR;
                                scsirate |= offset & SOFS;
                        }
                        if (active) {
                                u_int sxfrctl0;

                                sxfrctl0 = ahc_inb(ahc, SXFRCTL0);
                                sxfrctl0 &= ~FAST20;
                                if (tstate->ultraenb & devinfo->target_mask)
                                        sxfrctl0 |= FAST20;
                                ahc_outb(ahc, SXFRCTL0, sxfrctl0);
                        }
                }
                if (active) {
                        ahc_outb(ahc, SCSIRATE, scsirate);
                        if ((ahc->features & AHC_ULTRA2) != 0)
                                ahc_outb(ahc, SCSIOFFSET, offset);
                }

                tinfo->scsirate = scsirate;
                tinfo->curr.period = period;
                tinfo->curr.offset = offset;
                tinfo->curr.ppr_options = ppr_options;

                ahc_send_async(ahc, devinfo->channel, devinfo->target,
                               CAM_LUN_WILDCARD, AC_TRANSFER_NEG);
                if (bootverbose) {
                        if (offset != 0) {
                                printf("%s: target %d synchronous at %sMHz%s, "
                                       "offset = 0x%x\n", ahc_name(ahc),
                                       devinfo->target, syncrate->rate,
                                       (ppr_options & MSG_EXT_PPR_DT_REQ)
                                       ? " DT" : "", offset);
                        } else {
                                printf("%s: target %d using "
                                       "asynchronous transfers\n",
                                       ahc_name(ahc), devinfo->target);
                        }
                }
        }

        update_needed += ahc_update_neg_request(ahc, devinfo, tstate,
                                                tinfo, AHC_NEG_TO_GOAL);

        if (update_needed)
                ahc_update_pending_scbs(ahc);
}

/*
 * Update the user/goal/curr tables of wide negotiation
 * parameters as well as, in the case of a current or active update,
 * any data structures on the host controller.  In the case of an
 * active update, the specified target is currently talking to us on
 * the bus, so the transfer parameter update must take effect
 * immediately.
 */
void
ahc_set_width(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
              u_int width, u_int type, int paused)
{
        struct        ahc_initiator_tinfo *tinfo;
        struct        ahc_tmode_tstate *tstate;
        u_int        oldwidth;
        int        active;
        int        update_needed;

        active = (type & AHC_TRANS_ACTIVE) == AHC_TRANS_ACTIVE;
        update_needed = 0;
        tinfo = ahc_fetch_transinfo(ahc, devinfo->channel, devinfo->our_scsiid,
                                    devinfo->target, &tstate);

        if ((type & AHC_TRANS_USER) != 0)
                tinfo->user.width = width;

        if ((type & AHC_TRANS_GOAL) != 0)
                tinfo->goal.width = width;

        oldwidth = tinfo->curr.width;
        if ((type & AHC_TRANS_CUR) != 0 && oldwidth != width) {
                u_int        scsirate;

                update_needed++;
                scsirate =  tinfo->scsirate;
                scsirate &= ~WIDEXFER;
                if (width == MSG_EXT_WDTR_BUS_16_BIT)
                        scsirate |= WIDEXFER;

                tinfo->scsirate = scsirate;

                if (active)
                        ahc_outb(ahc, SCSIRATE, scsirate);

                tinfo->curr.width = width;

                ahc_send_async(ahc, devinfo->channel, devinfo->target,
                               CAM_LUN_WILDCARD, AC_TRANSFER_NEG);
                if (bootverbose) {
                        printf("%s: target %d using %dbit transfers\n",
                               ahc_name(ahc), devinfo->target,
                               8 * (0x01 << width));
                }
        }

        update_needed += ahc_update_neg_request(ahc, devinfo, tstate,
                                                tinfo, AHC_NEG_TO_GOAL);
        if (update_needed)
                ahc_update_pending_scbs(ahc);
}

/*
 * Update the current state of tagged queuing for a given target.
 */
static void
ahc_set_tags(struct ahc_softc *ahc, struct scsi_cmnd *cmd,
             struct ahc_devinfo *devinfo, ahc_queue_alg alg)
{
        struct scsi_device *sdev = cmd->device;

         ahc_platform_set_tags(ahc, sdev, devinfo, alg);
         ahc_send_async(ahc, devinfo->channel, devinfo->target,
                        devinfo->lun, AC_TRANSFER_NEG);
}

/*
 * When the transfer settings for a connection change, update any
 * in-transit SCBs to contain the new data so the hardware will
 * be set correctly during future (re)selections.
 */
static void
ahc_update_pending_scbs(struct ahc_softc *ahc)
{
        struct        scb *pending_scb;
        int        pending_scb_count;
        int        i;
        int        paused;
        u_int        saved_scbptr;

        /*
         * Traverse the pending SCB list and ensure that all of the
         * SCBs there have the proper settings.
         */
        pending_scb_count = 0;
        LIST_FOREACH(pending_scb, &ahc->pending_scbs, pending_links) {
                struct ahc_devinfo devinfo;
                struct hardware_scb *pending_hscb;
                struct ahc_initiator_tinfo *tinfo;
                struct ahc_tmode_tstate *tstate;

                ahc_scb_devinfo(ahc, &devinfo, pending_scb);
                tinfo = ahc_fetch_transinfo(ahc, devinfo.channel,
                                            devinfo.our_scsiid,
                                            devinfo.target, &tstate);
                pending_hscb = pending_scb->hscb;
                pending_hscb->control &= ~ULTRAENB;
                if ((tstate->ultraenb & devinfo.target_mask) != 0)
                        pending_hscb->control |= ULTRAENB;
                pending_hscb->scsirate = tinfo->scsirate;
                pending_hscb->scsioffset = tinfo->curr.offset;
                if ((tstate->auto_negotiate & devinfo.target_mask) == 0
                 && (pending_scb->flags & SCB_AUTO_NEGOTIATE) != 0) {
                        pending_scb->flags &= ~SCB_AUTO_NEGOTIATE;
                        pending_hscb->control &= ~MK_MESSAGE;
                }
                ahc_sync_scb(ahc, pending_scb,
                             BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
                pending_scb_count++;
        }

        if (pending_scb_count == 0)
                return;

        if (ahc_is_paused(ahc)) {
                paused = 1;
        } else {
                paused = 0;
                ahc_pause(ahc);
        }

        saved_scbptr = ahc_inb(ahc, SCBPTR);
        /* Ensure that the hscbs down on the card match the new information */
        for (i = 0; i < ahc->scb_data->maxhscbs; i++) {
                struct        hardware_scb *pending_hscb;
                u_int        control;
                u_int        scb_tag;

                ahc_outb(ahc, SCBPTR, i);
                scb_tag = ahc_inb(ahc, SCB_TAG);
                pending_scb = ahc_lookup_scb(ahc, scb_tag);
                if (pending_scb == NULL)
                        continue;

                pending_hscb = pending_scb->hscb;
                control = ahc_inb(ahc, SCB_CONTROL);
                control &= ~(ULTRAENB|MK_MESSAGE);
                control |= pending_hscb->control & (ULTRAENB|MK_MESSAGE);
                ahc_outb(ahc, SCB_CONTROL, control);
                ahc_outb(ahc, SCB_SCSIRATE, pending_hscb->scsirate);
                ahc_outb(ahc, SCB_SCSIOFFSET, pending_hscb->scsioffset);
        }
        ahc_outb(ahc, SCBPTR, saved_scbptr);

        if (paused == 0)
                ahc_unpause(ahc);
}

/**************************** Pathing Information *****************************/
static void
ahc_fetch_devinfo(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        u_int        saved_scsiid;
        role_t        role;
        int        our_id;

        if (ahc_inb(ahc, SSTAT0) & TARGET)
                role = ROLE_TARGET;
        else
                role = ROLE_INITIATOR;

        if (role == ROLE_TARGET
         && (ahc->features & AHC_MULTI_TID) != 0
         && (ahc_inb(ahc, SEQ_FLAGS)
            & (CMDPHASE_PENDING|TARG_CMD_PENDING|NO_DISCONNECT)) != 0) {
                /* We were selected, so pull our id from TARGIDIN */
                our_id = ahc_inb(ahc, TARGIDIN) & OID;
        } else if ((ahc->features & AHC_ULTRA2) != 0)
                our_id = ahc_inb(ahc, SCSIID_ULTRA2) & OID;
        else
                our_id = ahc_inb(ahc, SCSIID) & OID;

        saved_scsiid = ahc_inb(ahc, SAVED_SCSIID);
        ahc_compile_devinfo(devinfo,
                            our_id,
                            SCSIID_TARGET(ahc, saved_scsiid),
                            ahc_inb(ahc, SAVED_LUN),
                            SCSIID_CHANNEL(ahc, saved_scsiid),
                            role);
}

static const struct ahc_phase_table_entry*
ahc_lookup_phase_entry(int phase)
{
        const struct ahc_phase_table_entry *entry;
        const struct ahc_phase_table_entry *last_entry;

        /*
         * num_phases doesn't include the default entry which
         * will be returned if the phase doesn't match.
         */
        last_entry = &ahc_phase_table[num_phases];
        for (entry = ahc_phase_table; entry < last_entry; entry++) {
                if (phase == entry->phase)
                        break;
        }
        return (entry);
}

void
ahc_compile_devinfo(struct ahc_devinfo *devinfo, u_int our_id, u_int target,
                    u_int lun, char channel, role_t role)
{
        devinfo->our_scsiid = our_id;
        devinfo->target = target;
        devinfo->lun = lun;
        devinfo->target_offset = target;
        devinfo->channel = channel;
        devinfo->role = role;
        if (channel == 'B')
                devinfo->target_offset += 8;
        devinfo->target_mask = (0x01 << devinfo->target_offset);
}

void
ahc_print_devinfo(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        printf("%s:%c:%d:%d: ", ahc_name(ahc), devinfo->channel,
               devinfo->target, devinfo->lun);
}

static void
ahc_scb_devinfo(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                struct scb *scb)
{
        role_t        role;
        int        our_id;

        our_id = SCSIID_OUR_ID(scb->hscb->scsiid);
        role = ROLE_INITIATOR;
        if ((scb->flags & SCB_TARGET_SCB) != 0)
                role = ROLE_TARGET;
        ahc_compile_devinfo(devinfo, our_id, SCB_GET_TARGET(ahc, scb),
                            SCB_GET_LUN(scb), SCB_GET_CHANNEL(ahc, scb), role);
}


/************************ Message Phase Processing ****************************/
static void
ahc_assert_atn(struct ahc_softc *ahc)
{
        u_int scsisigo;

        scsisigo = ATNO;
        if ((ahc->features & AHC_DT) == 0)
                scsisigo |= ahc_inb(ahc, SCSISIGI);
        ahc_outb(ahc, SCSISIGO, scsisigo);
}

/*
 * When an initiator transaction with the MK_MESSAGE flag either reconnects
 * or enters the initial message out phase, we are interrupted.  Fill our
 * outgoing message buffer with the appropriate message and beging handing
 * the message phase(s) manually.
 */
static void
ahc_setup_initiator_msgout(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                           struct scb *scb)
{
        /*
         * To facilitate adding multiple messages together,
         * each routine should increment the index and len
         * variables instead of setting them explicitly.
         */
        ahc->msgout_index = 0;
        ahc->msgout_len = 0;

        if ((scb->flags & SCB_DEVICE_RESET) == 0
         && ahc_inb(ahc, MSG_OUT) == MSG_IDENTIFYFLAG) {
                u_int identify_msg;

                identify_msg = MSG_IDENTIFYFLAG | SCB_GET_LUN(scb);
                if ((scb->hscb->control & DISCENB) != 0)
                        identify_msg |= MSG_IDENTIFY_DISCFLAG;
                ahc->msgout_buf[ahc->msgout_index++] = identify_msg;
                ahc->msgout_len++;

                if ((scb->hscb->control & TAG_ENB) != 0) {
                        ahc->msgout_buf[ahc->msgout_index++] =
                            scb->hscb->control & (TAG_ENB|SCB_TAG_TYPE);
                        ahc->msgout_buf[ahc->msgout_index++] = scb->hscb->tag;
                        ahc->msgout_len += 2;
                }
        }

        if (scb->flags & SCB_DEVICE_RESET) {
                ahc->msgout_buf[ahc->msgout_index++] = MSG_BUS_DEV_RESET;
                ahc->msgout_len++;
                ahc_print_path(ahc, scb);
                printf("Bus Device Reset Message Sent\n");
                /*
                 * Clear our selection hardware in advance of
                 * the busfree.  We may have an entry in the waiting
                 * Q for this target, and we don't want to go about
                 * selecting while we handle the busfree and blow it
                 * away.
                 */
                ahc_outb(ahc, SCSISEQ, (ahc_inb(ahc, SCSISEQ) & ~ENSELO));
        } else if ((scb->flags & SCB_ABORT) != 0) {
                if ((scb->hscb->control & TAG_ENB) != 0)
                        ahc->msgout_buf[ahc->msgout_index++] = MSG_ABORT_TAG;
                else
                        ahc->msgout_buf[ahc->msgout_index++] = MSG_ABORT;
                ahc->msgout_len++;
                ahc_print_path(ahc, scb);
                printf("Abort%s Message Sent\n",
                       (scb->hscb->control & TAG_ENB) != 0 ? " Tag" : "");
                /*
                 * Clear our selection hardware in advance of
                 * the busfree.  We may have an entry in the waiting
                 * Q for this target, and we don't want to go about
                 * selecting while we handle the busfree and blow it
                 * away.
                 */
                ahc_outb(ahc, SCSISEQ, (ahc_inb(ahc, SCSISEQ) & ~ENSELO));
        } else if ((scb->flags & (SCB_AUTO_NEGOTIATE|SCB_NEGOTIATE)) != 0) {
                ahc_build_transfer_msg(ahc, devinfo);
        } else {
                printf("ahc_intr: AWAITING_MSG for an SCB that "
                       "does not have a waiting message\n");
                printf("SCSIID = %x, target_mask = %x\n", scb->hscb->scsiid,
                       devinfo->target_mask);
                panic("SCB = %d, SCB Control = %x, MSG_OUT = %x "
                      "SCB flags = %x", scb->hscb->tag, scb->hscb->control,
                      ahc_inb(ahc, MSG_OUT), scb->flags);
        }

        /*
         * Clear the MK_MESSAGE flag from the SCB so we aren't
         * asked to send this message again.
         */
        ahc_outb(ahc, SCB_CONTROL, ahc_inb(ahc, SCB_CONTROL) & ~MK_MESSAGE);
        scb->hscb->control &= ~MK_MESSAGE;
        ahc->msgout_index = 0;
        ahc->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
}

/*
 * Build an appropriate transfer negotiation message for the
 * currently active target.
 */
static void
ahc_build_transfer_msg(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        /*
         * We need to initiate transfer negotiations.
         * If our current and goal settings are identical,
         * we want to renegotiate due to a check condition.
         */
        struct        ahc_initiator_tinfo *tinfo;
        struct        ahc_tmode_tstate *tstate;
        const struct ahc_syncrate *rate;
        int        dowide;
        int        dosync;
        int        doppr;
        u_int        period;
        u_int        ppr_options;
        u_int        offset;

        tinfo = ahc_fetch_transinfo(ahc, devinfo->channel, devinfo->our_scsiid,
                                    devinfo->target, &tstate);
        /*
         * Filter our period based on the current connection.
         * If we can't perform DT transfers on this segment (not in LVD
         * mode for instance), then our decision to issue a PPR message
         * may change.
         */
        period = tinfo->goal.period;
        offset = tinfo->goal.offset;
        ppr_options = tinfo->goal.ppr_options;
        /* Target initiated PPR is not allowed in the SCSI spec */
        if (devinfo->role == ROLE_TARGET)
                ppr_options = 0;
        rate = ahc_devlimited_syncrate(ahc, tinfo, &period,
                                       &ppr_options, devinfo->role);
        dowide = tinfo->curr.width != tinfo->goal.width;
        dosync = tinfo->curr.offset != offset || tinfo->curr.period != period;
        /*
         * Only use PPR if we have options that need it, even if the device
         * claims to support it.  There might be an expander in the way
         * that doesn't.
         */
        doppr = ppr_options != 0;

        if (!dowide && !dosync && !doppr) {
                dowide = tinfo->goal.width != MSG_EXT_WDTR_BUS_8_BIT;
                dosync = tinfo->goal.offset != 0;
        }

        if (!dowide && !dosync && !doppr) {
                /*
                 * Force async with a WDTR message if we have a wide bus,
                 * or just issue an SDTR with a 0 offset.
                 */
                if ((ahc->features & AHC_WIDE) != 0)
                        dowide = 1;
                else
                        dosync = 1;

                if (bootverbose) {
                        ahc_print_devinfo(ahc, devinfo);
                        printf("Ensuring async\n");
                }
        }

        /* Target initiated PPR is not allowed in the SCSI spec */
        if (devinfo->role == ROLE_TARGET)
                doppr = 0;

        /*
         * Both the PPR message and SDTR message require the
         * goal syncrate to be limited to what the target device
         * is capable of handling (based on whether an LVD->SE
         * expander is on the bus), so combine these two cases.
         * Regardless, guarantee that if we are using WDTR and SDTR
         * messages that WDTR comes first.
         */
        if (doppr || (dosync && !dowide)) {

                offset = tinfo->goal.offset;
                ahc_validate_offset(ahc, tinfo, rate, &offset,
                                    doppr ? tinfo->goal.width
                                          : tinfo->curr.width,
                                    devinfo->role);
                if (doppr) {
                        ahc_construct_ppr(ahc, devinfo, period, offset,
                                          tinfo->goal.width, ppr_options);
                } else {
                        ahc_construct_sdtr(ahc, devinfo, period, offset);
                }
        } else {
                ahc_construct_wdtr(ahc, devinfo, tinfo->goal.width);
        }
}

/*
 * Build a synchronous negotiation message in our message
 * buffer based on the input parameters.
 */
static void
ahc_construct_sdtr(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                   u_int period, u_int offset)
{
        if (offset == 0)
                period = AHC_ASYNC_XFER_PERIOD;
        ahc->msgout_index += spi_populate_sync_msg(
                        ahc->msgout_buf + ahc->msgout_index, period, offset);
        ahc->msgout_len += 5;
        if (bootverbose) {
                printf("(%s:%c:%d:%d): Sending SDTR period %x, offset %x\n",
                       ahc_name(ahc), devinfo->channel, devinfo->target,
                       devinfo->lun, period, offset);
        }
}

/*
 * Build a wide negotiation message in our message
 * buffer based on the input parameters.
 */
static void
ahc_construct_wdtr(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                   u_int bus_width)
{
        ahc->msgout_index += spi_populate_width_msg(
                        ahc->msgout_buf + ahc->msgout_index, bus_width);
        ahc->msgout_len += 4;
        if (bootverbose) {
                printf("(%s:%c:%d:%d): Sending WDTR %x\n",
                       ahc_name(ahc), devinfo->channel, devinfo->target,
                       devinfo->lun, bus_width);
        }
}

/*
 * Build a parallel protocol request message in our message
 * buffer based on the input parameters.
 */
static void
ahc_construct_ppr(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                  u_int period, u_int offset, u_int bus_width,
                  u_int ppr_options)
{
        if (offset == 0)
                period = AHC_ASYNC_XFER_PERIOD;
        ahc->msgout_index += spi_populate_ppr_msg(
                        ahc->msgout_buf + ahc->msgout_index, period, offset,
                        bus_width, ppr_options);
        ahc->msgout_len += 8;
        if (bootverbose) {
                printf("(%s:%c:%d:%d): Sending PPR bus_width %x, period %x, "
                       "offset %x, ppr_options %x\n", ahc_name(ahc),
                       devinfo->channel, devinfo->target, devinfo->lun,
                       bus_width, period, offset, ppr_options);
        }
}

/*
 * Clear any active message state.
 */
static void
ahc_clear_msg_state(struct ahc_softc *ahc)
{
        ahc->msgout_len = 0;
        ahc->msgin_index = 0;
        ahc->msg_type = MSG_TYPE_NONE;
        if ((ahc_inb(ahc, SCSISIGI) & ATNI) != 0) {
                /*
                 * The target didn't care to respond to our
                 * message request, so clear ATN.
                 */
                ahc_outb(ahc, CLRSINT1, CLRATNO);
        }
        ahc_outb(ahc, MSG_OUT, MSG_NOOP);
        ahc_outb(ahc, SEQ_FLAGS2,
                 ahc_inb(ahc, SEQ_FLAGS2) & ~TARGET_MSG_PENDING);
}

static void
ahc_handle_proto_violation(struct ahc_softc *ahc)
{
        struct        ahc_devinfo devinfo;
        struct        scb *scb;
        u_int        scbid;
        u_int        seq_flags;
        u_int        curphase;
        u_int        lastphase;
        int        found;

        ahc_fetch_devinfo(ahc, &devinfo);
        scbid = ahc_inb(ahc, SCB_TAG);
        scb = ahc_lookup_scb(ahc, scbid);
        seq_flags = ahc_inb(ahc, SEQ_FLAGS);
        curphase = ahc_inb(ahc, SCSISIGI) & PHASE_MASK;
        lastphase = ahc_inb(ahc, LASTPHASE);
        if ((seq_flags & NOT_IDENTIFIED) != 0) {

                /*
                 * The reconnecting target either did not send an
                 * identify message, or did, but we didn't find an SCB
                 * to match.
                 */
                ahc_print_devinfo(ahc, &devinfo);
                printf("Target did not send an IDENTIFY message. "
                       "LASTPHASE = 0x%x.\n", lastphase);
                scb = NULL;
        } else if (scb == NULL) {
                /*
                 * We don't seem to have an SCB active for this
                 * transaction.  Print an error and reset the bus.
                 */
                ahc_print_devinfo(ahc, &devinfo);
                printf("No SCB found during protocol violation\n");
                goto proto_violation_reset;
        } else {
                ahc_set_transaction_status(scb, CAM_SEQUENCE_FAIL);
                if ((seq_flags & NO_CDB_SENT) != 0) {
                        ahc_print_path(ahc, scb);
                        printf("No or incomplete CDB sent to device.\n");
                } else if ((ahc_inb(ahc, SCB_CONTROL) & STATUS_RCVD) == 0) {
                        /*
                         * The target never bothered to provide status to
                         * us prior to completing the command.  Since we don't
                         * know the disposition of this command, we must attempt
                         * to abort it.  Assert ATN and prepare to send an abort
                         * message.
                         */
                        ahc_print_path(ahc, scb);
                        printf("Completed command without status.\n");
                } else {
                        ahc_print_path(ahc, scb);
                        printf("Unknown protocol violation.\n");
                        ahc_dump_card_state(ahc);
                }
        }
        if ((lastphase & ~P_DATAIN_DT) == 0
         || lastphase == P_COMMAND) {
proto_violation_reset:
                /*
                 * Target either went directly to data/command
                 * phase or didn't respond to our ATN.
                 * The only safe thing to do is to blow
                 * it away with a bus reset.
                 */
                found = ahc_reset_channel(ahc, 'A', TRUE);
                printf("%s: Issued Channel %c Bus Reset. "
                       "%d SCBs aborted\n", ahc_name(ahc), 'A', found);
        } else {
                /*
                 * Leave the selection hardware off in case
                 * this abort attempt will affect yet to
                 * be sent commands.
                 */
                ahc_outb(ahc, SCSISEQ,
                         ahc_inb(ahc, SCSISEQ) & ~ENSELO);
                ahc_assert_atn(ahc);
                ahc_outb(ahc, MSG_OUT, HOST_MSG);
                if (scb == NULL) {
                        ahc_print_devinfo(ahc, &devinfo);
                        ahc->msgout_buf[0] = MSG_ABORT_TASK;
                        ahc->msgout_len = 1;
                        ahc->msgout_index = 0;
                        ahc->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                } else {
                        ahc_print_path(ahc, scb);
                        scb->flags |= SCB_ABORT;
                }
                printf("Protocol violation %s.  Attempting to abort.\n",
                       ahc_lookup_phase_entry(curphase)->phasemsg);
        }
}

/*
 * Manual message loop handler.
 */
static void
ahc_handle_message_phase(struct ahc_softc *ahc)
{
        struct        ahc_devinfo devinfo;
        u_int        bus_phase;
        int        end_session;

        ahc_fetch_devinfo(ahc, &devinfo);
        end_session = FALSE;
        bus_phase = ahc_inb(ahc, SCSISIGI) & PHASE_MASK;

reswitch:
        switch (ahc->msg_type) {
        case MSG_TYPE_INITIATOR_MSGOUT:
        {
                int lastbyte;
                int phasemis;
                int msgdone;

                if (ahc->msgout_len == 0)
                        panic("HOST_MSG_LOOP interrupt with no active message");

#ifdef AHC_DEBUG
                if ((ahc_debug & AHC_SHOW_MESSAGES) != 0) {
                        ahc_print_devinfo(ahc, &devinfo);
                        printf("INITIATOR_MSG_OUT");
                }
#endif
                phasemis = bus_phase != P_MESGOUT;
                if (phasemis) {
#ifdef AHC_DEBUG
                        if ((ahc_debug & AHC_SHOW_MESSAGES) != 0) {
                                printf(" PHASEMIS %s\n",
                                       ahc_lookup_phase_entry(bus_phase)
                                                             ->phasemsg);
                        }
#endif
                        if (bus_phase == P_MESGIN) {
                                /*
                                 * Change gears and see if
                                 * this messages is of interest to
                                 * us or should be passed back to
                                 * the sequencer.
                                 */
                                ahc_outb(ahc, CLRSINT1, CLRATNO);
                                ahc->send_msg_perror = FALSE;
                                ahc->msg_type = MSG_TYPE_INITIATOR_MSGIN;
                                ahc->msgin_index = 0;
                                goto reswitch;
                        }
                        end_session = TRUE;
                        break;
                }

                if (ahc->send_msg_perror) {
                        ahc_outb(ahc, CLRSINT1, CLRATNO);
                        ahc_outb(ahc, CLRSINT1, CLRREQINIT);
#ifdef AHC_DEBUG
                        if ((ahc_debug & AHC_SHOW_MESSAGES) != 0)
                                printf(" byte 0x%x\n", ahc->send_msg_perror);
#endif
                        ahc_outb(ahc, SCSIDATL, MSG_PARITY_ERROR);
                        break;
                }

                msgdone        = ahc->msgout_index == ahc->msgout_len;
                if (msgdone) {
                        /*
                         * The target has requested a retry.
                         * Re-assert ATN, reset our message index to
                         * 0, and try again.
                         */
                        ahc->msgout_index = 0;
                        ahc_assert_atn(ahc);
                }

                lastbyte = ahc->msgout_index == (ahc->msgout_len - 1);
                if (lastbyte) {
                        /* Last byte is signified by dropping ATN */
                        ahc_outb(ahc, CLRSINT1, CLRATNO);
                }

                /*
                 * Clear our interrupt status and present
                 * the next byte on the bus.
                 */
                ahc_outb(ahc, CLRSINT1, CLRREQINIT);
#ifdef AHC_DEBUG
                if ((ahc_debug & AHC_SHOW_MESSAGES) != 0)
                        printf(" byte 0x%x\n",
                               ahc->msgout_buf[ahc->msgout_index]);
#endif
                ahc_outb(ahc, SCSIDATL, ahc->msgout_buf[ahc->msgout_index++]);
                break;
        }
        case MSG_TYPE_INITIATOR_MSGIN:
        {
                int phasemis;
                int message_done;

#ifdef AHC_DEBUG
                if ((ahc_debug & AHC_SHOW_MESSAGES) != 0) {
                        ahc_print_devinfo(ahc, &devinfo);
                        printf("INITIATOR_MSG_IN");
                }
#endif
                phasemis = bus_phase != P_MESGIN;
                if (phasemis) {
#ifdef AHC_DEBUG
                        if ((ahc_debug & AHC_SHOW_MESSAGES) != 0) {
                                printf(" PHASEMIS %s\n",
                                       ahc_lookup_phase_entry(bus_phase)
                                                             ->phasemsg);
                        }
#endif
                        ahc->msgin_index = 0;
                        if (bus_phase == P_MESGOUT
                         && (ahc->send_msg_perror == TRUE
                          || (ahc->msgout_len != 0
                           && ahc->msgout_index == 0))) {
                                ahc->msg_type = MSG_TYPE_INITIATOR_MSGOUT;
                                goto reswitch;
                        }
                        end_session = TRUE;
                        break;
                }

                /* Pull the byte in without acking it */
                ahc->msgin_buf[ahc->msgin_index] = ahc_inb(ahc, SCSIBUSL);
#ifdef AHC_DEBUG
                if ((ahc_debug & AHC_SHOW_MESSAGES) != 0)
                        printf(" byte 0x%x\n",
                               ahc->msgin_buf[ahc->msgin_index]);
#endif

                message_done = ahc_parse_msg(ahc, &devinfo);

                if (message_done) {
                        /*
                         * Clear our incoming message buffer in case there
                         * is another message following this one.
                         */
                        ahc->msgin_index = 0;

                        /*
                         * If this message illicited a response,
                         * assert ATN so the target takes us to the
                         * message out phase.
                         */
                        if (ahc->msgout_len != 0) {
#ifdef AHC_DEBUG
                                if ((ahc_debug & AHC_SHOW_MESSAGES) != 0) {
                                        ahc_print_devinfo(ahc, &devinfo);
                                        printf("Asserting ATN for response\n");
                                }
#endif
                                ahc_assert_atn(ahc);
                        }
                } else 
                        ahc->msgin_index++;

                if (message_done == MSGLOOP_TERMINATED) {
                        end_session = TRUE;
                } else {
                        /* Ack the byte */
                        ahc_outb(ahc, CLRSINT1, CLRREQINIT);
                        ahc_inb(ahc, SCSIDATL);
                }
                break;
        }
        case MSG_TYPE_TARGET_MSGIN:
        {
                int msgdone;
                int msgout_request;

                if (ahc->msgout_len == 0)
                        panic("Target MSGIN with no active message");

                /*
                 * If we interrupted a mesgout session, the initiator
                 * will not know this until our first REQ.  So, we
                 * only honor mesgout requests after we've sent our
                 * first byte.
                 */
                if ((ahc_inb(ahc, SCSISIGI) & ATNI) != 0
                 && ahc->msgout_index > 0)
                        msgout_request = TRUE;
                else
                        msgout_request = FALSE;

                if (msgout_request) {

                        /*
                         * Change gears and see if
                         * this messages is of interest to
                         * us or should be passed back to
                         * the sequencer.
                         */
                        ahc->msg_type = MSG_TYPE_TARGET_MSGOUT;
                        ahc_outb(ahc, SCSISIGO, P_MESGOUT | BSYO);
                        ahc->msgin_index = 0;
                        /* Dummy read to REQ for first byte */
                        ahc_inb(ahc, SCSIDATL);
                        ahc_outb(ahc, SXFRCTL0,
                                 ahc_inb(ahc, SXFRCTL0) | SPIOEN);
                        break;
                }

                msgdone = ahc->msgout_index == ahc->msgout_len;
                if (msgdone) {
                        ahc_outb(ahc, SXFRCTL0,
                                 ahc_inb(ahc, SXFRCTL0) & ~SPIOEN);
                        end_session = TRUE;
                        break;
                }

                /*
                 * Present the next byte on the bus.
                 */
                ahc_outb(ahc, SXFRCTL0, ahc_inb(ahc, SXFRCTL0) | SPIOEN);
                ahc_outb(ahc, SCSIDATL, ahc->msgout_buf[ahc->msgout_index++]);
                break;
        }
        case MSG_TYPE_TARGET_MSGOUT:
        {
                int lastbyte;
                int msgdone;

                /*
                 * The initiator signals that this is
                 * the last byte by dropping ATN.
                 */
                lastbyte = (ahc_inb(ahc, SCSISIGI) & ATNI) == 0;

                /*
                 * Read the latched byte, but turn off SPIOEN first
                 * so that we don't inadvertently cause a REQ for the
                 * next byte.
                 */
                ahc_outb(ahc, SXFRCTL0, ahc_inb(ahc, SXFRCTL0) & ~SPIOEN);
                ahc->msgin_buf[ahc->msgin_index] = ahc_inb(ahc, SCSIDATL);
                msgdone = ahc_parse_msg(ahc, &devinfo);
                if (msgdone == MSGLOOP_TERMINATED) {
                        /*
                         * The message is *really* done in that it caused
                         * us to go to bus free.  The sequencer has already
                         * been reset at this point, so pull the ejection
                         * handle.
                         */
                        return;
                }
                
                ahc->msgin_index++;

                /*
                 * XXX Read spec about initiator dropping ATN too soon
                 *     and use msgdone to detect it.
                 */
                if (msgdone == MSGLOOP_MSGCOMPLETE) {
                        ahc->msgin_index = 0;

                        /*
                         * If this message illicited a response, transition
                         * to the Message in phase and send it.
                         */
                        if (ahc->msgout_len != 0) {
                                ahc_outb(ahc, SCSISIGO, P_MESGIN | BSYO);
                                ahc_outb(ahc, SXFRCTL0,
                                         ahc_inb(ahc, SXFRCTL0) | SPIOEN);
                                ahc->msg_type = MSG_TYPE_TARGET_MSGIN;
                                ahc->msgin_index = 0;
                                break;
                        }
                }

                if (lastbyte)
                        end_session = TRUE;
                else {
                        /* Ask for the next byte. */
                        ahc_outb(ahc, SXFRCTL0,
                                 ahc_inb(ahc, SXFRCTL0) | SPIOEN);
                }

                break;
        }
        default:
                panic("Unknown REQINIT message type");
        }

        if (end_session) {
                ahc_clear_msg_state(ahc);
                ahc_outb(ahc, RETURN_1, EXIT_MSG_LOOP);
        } else
                ahc_outb(ahc, RETURN_1, CONT_MSG_LOOP);
}

/*
 * See if we sent a particular extended message to the target.
 * If "full" is true, return true only if the target saw the full
 * message.  If "full" is false, return true if the target saw at
 * least the first byte of the message.
 */
static int
ahc_sent_msg(struct ahc_softc *ahc, ahc_msgtype type, u_int msgval, int full)
{
        int found;
        u_int index;

        found = FALSE;
        index = 0;

        while (index < ahc->msgout_len) {
                if (ahc->msgout_buf[index] == MSG_EXTENDED) {
                        u_int end_index;

                        end_index = index + 1 + ahc->msgout_buf[index + 1];
                        if (ahc->msgout_buf[index+2] == msgval
                         && type == AHCMSG_EXT) {

                                if (full) {
                                        if (ahc->msgout_index > end_index)
                                                found = TRUE;
                                } else if (ahc->msgout_index > index)
                                        found = TRUE;
                        }
                        index = end_index;
                } else if (ahc->msgout_buf[index] >= MSG_SIMPLE_TASK
                        && ahc->msgout_buf[index] <= MSG_IGN_WIDE_RESIDUE) {

                        /* Skip tag type and tag id or residue param*/
                        index += 2;
                } else {
                        /* Single byte message */
                        if (type == AHCMSG_1B
                         && ahc->msgout_buf[index] == msgval
                         && ahc->msgout_index > index)
                                found = TRUE;
                        index++;
                }

                if (found)
                        break;
        }
        return (found);
}

/*
 * Wait for a complete incoming message, parse it, and respond accordingly.
 */
static int
ahc_parse_msg(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        struct        ahc_initiator_tinfo *tinfo;
        struct        ahc_tmode_tstate *tstate;
        int        reject;
        int        done;
        int        response;
        u_int        targ_scsirate;

        done = MSGLOOP_IN_PROG;
        response = FALSE;
        reject = FALSE;
        tinfo = ahc_fetch_transinfo(ahc, devinfo->channel, devinfo->our_scsiid,
                                    devinfo->target, &tstate);
        targ_scsirate = tinfo->scsirate;

        /*
         * Parse as much of the message as is available,
         * rejecting it if we don't support it.  When
         * the entire message is available and has been
         * handled, return MSGLOOP_MSGCOMPLETE, indicating
         * that we have parsed an entire message.
         *
         * In the case of extended messages, we accept the length
         * byte outright and perform more checking once we know the
         * extended message type.
         */
        switch (ahc->msgin_buf[0]) {
        case MSG_DISCONNECT:
        case MSG_SAVEDATAPOINTER:
        case MSG_CMDCOMPLETE:
        case MSG_RESTOREPOINTERS:
        case MSG_IGN_WIDE_RESIDUE:
                /*
                 * End our message loop as these are messages
                 * the sequencer handles on its own.
                 */
                done = MSGLOOP_TERMINATED;
                break;
        case MSG_MESSAGE_REJECT:
                response = ahc_handle_msg_reject(ahc, devinfo);
                /* FALLTHROUGH */
        case MSG_NOOP:
                done = MSGLOOP_MSGCOMPLETE;
                break;
        case MSG_EXTENDED:
        {
                /* Wait for enough of the message to begin validation */
                if (ahc->msgin_index < 2)
                        break;
                switch (ahc->msgin_buf[2]) {
                case MSG_EXT_SDTR:
                {
                        const struct ahc_syncrate *syncrate;
                        u_int         period;
                        u_int         ppr_options;
                        u_int         offset;
                        u_int         saved_offset;
                        
                        if (ahc->msgin_buf[1] != MSG_EXT_SDTR_LEN) {
                                reject = TRUE;
                                break;
                        }

                        /*
                         * Wait until we have both args before validating
                         * and acting on this message.
                         *
                         * Add one to MSG_EXT_SDTR_LEN to account for
                         * the extended message preamble.
                         */
                        if (ahc->msgin_index < (MSG_EXT_SDTR_LEN + 1))
                                break;

                        period = ahc->msgin_buf[3];
                        ppr_options = 0;
                        saved_offset = offset = ahc->msgin_buf[4];
                        syncrate = ahc_devlimited_syncrate(ahc, tinfo, &period,
                                                           &ppr_options,
                                                           devinfo->role);
                        ahc_validate_offset(ahc, tinfo, syncrate, &offset,
                                            targ_scsirate & WIDEXFER,
                                            devinfo->role);
                        if (bootverbose) {
                                printf("(%s:%c:%d:%d): Received "
                                       "SDTR period %x, offset %x\n\t"
                                       "Filtered to period %x, offset %x\n",
                                       ahc_name(ahc), devinfo->channel,
                                       devinfo->target, devinfo->lun,
                                       ahc->msgin_buf[3], saved_offset,
                                       period, offset);
                        }
                        ahc_set_syncrate(ahc, devinfo, 
                                         syncrate, period,
                                         offset, ppr_options,
                                         AHC_TRANS_ACTIVE|AHC_TRANS_GOAL,
                                         /*paused*/TRUE);

                        /*
                         * See if we initiated Sync Negotiation
                         * and didn't have to fall down to async
                         * transfers.
                         */
                        if (ahc_sent_msg(ahc, AHCMSG_EXT, MSG_EXT_SDTR, TRUE)) {
                                /* We started it */
                                if (saved_offset != offset) {
                                        /* Went too low - force async */
                                        reject = TRUE;
                                }
                        } else {
                                /*
                                 * Send our own SDTR in reply
                                 */
                                if (bootverbose
                                 && devinfo->role == ROLE_INITIATOR) {
                                        printf("(%s:%c:%d:%d): Target "
                                               "Initiated SDTR\n",
                                               ahc_name(ahc), devinfo->channel,
                                               devinfo->target, devinfo->lun);
                                }
                                ahc->msgout_index = 0;
                                ahc->msgout_len = 0;
                                ahc_construct_sdtr(ahc, devinfo,
                                                   period, offset);
                                ahc->msgout_index = 0;
                                response = TRUE;
                        }
                        done = MSGLOOP_MSGCOMPLETE;
                        break;
                }
                case MSG_EXT_WDTR:
                {
                        u_int bus_width;
                        u_int saved_width;
                        u_int sending_reply;

                        sending_reply = FALSE;
                        if (ahc->msgin_buf[1] != MSG_EXT_WDTR_LEN) {
                                reject = TRUE;
                                break;
                        }

                        /*
                         * Wait until we have our arg before validating
                         * and acting on this message.
                         *
                         * Add one to MSG_EXT_WDTR_LEN to account for
                         * the extended message preamble.
                         */
                        if (ahc->msgin_index < (MSG_EXT_WDTR_LEN + 1))
                                break;

                        bus_width = ahc->msgin_buf[3];
                        saved_width = bus_width;
                        ahc_validate_width(ahc, tinfo, &bus_width,
                                           devinfo->role);
                        if (bootverbose) {
                                printf("(%s:%c:%d:%d): Received WDTR "
                                       "%x filtered to %x\n",
                                       ahc_name(ahc), devinfo->channel,
                                       devinfo->target, devinfo->lun,
                                       saved_width, bus_width);
                        }

                        if (ahc_sent_msg(ahc, AHCMSG_EXT, MSG_EXT_WDTR, TRUE)) {
                                /*
                                 * Don't send a WDTR back to the
                                 * target, since we asked first.
                                 * If the width went higher than our
                                 * request, reject it.
                                 */
                                if (saved_width > bus_width) {
                                        reject = TRUE;
                                        printf("(%s:%c:%d:%d): requested %dBit "
                                               "transfers.  Rejecting...\n",
                                               ahc_name(ahc), devinfo->channel,
                                               devinfo->target, devinfo->lun,
                                               8 * (0x01 << bus_width));
                                        bus_width = 0;
                                }
                        } else {
                                /*
                                 * Send our own WDTR in reply
                                 */
                                if (bootverbose
                                 && devinfo->role == ROLE_INITIATOR) {
                                        printf("(%s:%c:%d:%d): Target "
                                               "Initiated WDTR\n",
                                               ahc_name(ahc), devinfo->channel,
                                               devinfo->target, devinfo->lun);
                                }
                                ahc->msgout_index = 0;
                                ahc->msgout_len = 0;
                                ahc_construct_wdtr(ahc, devinfo, bus_width);
                                ahc->msgout_index = 0;
                                response = TRUE;
                                sending_reply = TRUE;
                        }
                        /*
                         * After a wide message, we are async, but
                         * some devices don't seem to honor this portion
                         * of the spec.  Force a renegotiation of the
                         * sync component of our transfer agreement even
                         * if our goal is async.  By updating our width
                         * after forcing the negotiation, we avoid
                         * renegotiating for width.
                         */
                        ahc_update_neg_request(ahc, devinfo, tstate,
                                               tinfo, AHC_NEG_ALWAYS);
                        ahc_set_width(ahc, devinfo, bus_width,
                                      AHC_TRANS_ACTIVE|AHC_TRANS_GOAL,
                                      /*paused*/TRUE);
                        if (sending_reply == FALSE && reject == FALSE) {

                                /*
                                 * We will always have an SDTR to send.
                                 */
                                ahc->msgout_index = 0;
                                ahc->msgout_len = 0;
                                ahc_build_transfer_msg(ahc, devinfo);
                                ahc->msgout_index = 0;
                                response = TRUE;
                        }
                        done = MSGLOOP_MSGCOMPLETE;
                        break;
                }
                case MSG_EXT_PPR:
                {
                        const struct ahc_syncrate *syncrate;
                        u_int        period;
                        u_int        offset;
                        u_int        bus_width;
                        u_int        ppr_options;
                        u_int        saved_width;
                        u_int        saved_offset;
                        u_int        saved_ppr_options;

                        if (ahc->msgin_buf[1] != MSG_EXT_PPR_LEN) {
                                reject = TRUE;
                                break;
                        }

                        /*
                         * Wait until we have all args before validating
                         * and acting on this message.
                         *
                         * Add one to MSG_EXT_PPR_LEN to account for
                         * the extended message preamble.
                         */
                        if (ahc->msgin_index < (MSG_EXT_PPR_LEN + 1))
                                break;

                        period = ahc->msgin_buf[3];
                        offset = ahc->msgin_buf[5];
                        bus_width = ahc->msgin_buf[6];
                        saved_width = bus_width;
                        ppr_options = ahc->msgin_buf[7];
                        /*
                         * According to the spec, a DT only
                         * period factor with no DT option
                         * set implies async.
                         */
                        if ((ppr_options & MSG_EXT_PPR_DT_REQ) == 0
                         && period == 9)
                                offset = 0;
                        saved_ppr_options = ppr_options;
                        saved_offset = offset;

                        /*
                         * Mask out any options we don't support
                         * on any controller.  Transfer options are
                         * only available if we are negotiating wide.
                         */
                        ppr_options &= MSG_EXT_PPR_DT_REQ;
                        if (bus_width == 0)
                                ppr_options = 0;

                        ahc_validate_width(ahc, tinfo, &bus_width,
                                           devinfo->role);
                        syncrate = ahc_devlimited_syncrate(ahc, tinfo, &period,
                                                           &ppr_options,
                                                           devinfo->role);
                        ahc_validate_offset(ahc, tinfo, syncrate,
                                            &offset, bus_width,
                                            devinfo->role);

                        if (ahc_sent_msg(ahc, AHCMSG_EXT, MSG_EXT_PPR, TRUE)) {
                                /*
                                 * If we are unable to do any of the
                                 * requested options (we went too low),
                                 * then we'll have to reject the message.
                                 */
                                if (saved_width > bus_width
                                 || saved_offset != offset
                                 || saved_ppr_options != ppr_options) {
                                        reject = TRUE;
                                        period = 0;
                                        offset = 0;
                                        bus_width = 0;
                                        ppr_options = 0;
                                        syncrate = NULL;
                                }
                        } else {
                                if (devinfo->role != ROLE_TARGET)
                                        printf("(%s:%c:%d:%d): Target "
                                               "Initiated PPR\n",
                                               ahc_name(ahc), devinfo->channel,
                                               devinfo->target, devinfo->lun);
                                else
                                        printf("(%s:%c:%d:%d): Initiator "
                                               "Initiated PPR\n",
                                               ahc_name(ahc), devinfo->channel,
                                               devinfo->target, devinfo->lun);
                                ahc->msgout_index = 0;
                                ahc->msgout_len = 0;
                                ahc_construct_ppr(ahc, devinfo, period, offset,
                                                  bus_width, ppr_options);
                                ahc->msgout_index = 0;
                                response = TRUE;
                        }
                        if (bootverbose) {
                                printf("(%s:%c:%d:%d): Received PPR width %x, "
                                       "period %x, offset %x,options %x\n"
                                       "\tFiltered to width %x, period %x, "
                                       "offset %x, options %x\n",
                                       ahc_name(ahc), devinfo->channel,
                                       devinfo->target, devinfo->lun,
                                       saved_width, ahc->msgin_buf[3],
                                       saved_offset, saved_ppr_options,
                                       bus_width, period, offset, ppr_options);
                        }
                        ahc_set_width(ahc, devinfo, bus_width,
                                      AHC_TRANS_ACTIVE|AHC_TRANS_GOAL,
                                      /*paused*/TRUE);
                        ahc_set_syncrate(ahc, devinfo,
                                         syncrate, period,
                                         offset, ppr_options,
                                         AHC_TRANS_ACTIVE|AHC_TRANS_GOAL,
                                         /*paused*/TRUE);
                        done = MSGLOOP_MSGCOMPLETE;
                        break;
                }
                default:
                        /* Unknown extended message.  Reject it. */
                        reject = TRUE;
                        break;
                }
                break;
        }
#ifdef AHC_TARGET_MODE
        case MSG_BUS_DEV_RESET:
                ahc_handle_devreset(ahc, devinfo,
                                    CAM_BDR_SENT,
                                    "Bus Device Reset Received",
                                    /*verbose_level*/0);
                ahc_restart(ahc);
                done = MSGLOOP_TERMINATED;
                break;
        case MSG_ABORT_TAG:
        case MSG_ABORT:
        case MSG_CLEAR_QUEUE:
        {
                int tag;

                /* Target mode messages */
                if (devinfo->role != ROLE_TARGET) {
                        reject = TRUE;
                        break;
                }
                tag = SCB_LIST_NULL;
                if (ahc->msgin_buf[0] == MSG_ABORT_TAG)
                        tag = ahc_inb(ahc, INITIATOR_TAG);
                ahc_abort_scbs(ahc, devinfo->target, devinfo->channel,
                               devinfo->lun, tag, ROLE_TARGET,
                               CAM_REQ_ABORTED);

                tstate = ahc->enabled_targets[devinfo->our_scsiid];
                if (tstate != NULL) {
                        struct ahc_tmode_lstate* lstate;

                        lstate = tstate->enabled_luns[devinfo->lun];
                        if (lstate != NULL) {
                                ahc_queue_lstate_event(ahc, lstate,
                                                       devinfo->our_scsiid,
                                                       ahc->msgin_buf[0],
                                                       /*arg*/tag);
                                ahc_send_lstate_events(ahc, lstate);
                        }
                }
                ahc_restart(ahc);
                done = MSGLOOP_TERMINATED;
                break;
        }
#endif
        case MSG_TERM_IO_PROC:
        default:
                reject = TRUE;
                break;
        }

        if (reject) {
                /*
                 * Setup to reject the message.
                 */
                ahc->msgout_index = 0;
                ahc->msgout_len = 1;
                ahc->msgout_buf[0] = MSG_MESSAGE_REJECT;
                done = MSGLOOP_MSGCOMPLETE;
                response = TRUE;
        }

        if (done != MSGLOOP_IN_PROG && !response)
                /* Clear the outgoing message buffer */
                ahc->msgout_len = 0;

        return (done);
}

/*
 * Process a message reject message.
 */
static int
ahc_handle_msg_reject(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        /*
         * What we care about here is if we had an
         * outstanding SDTR or WDTR message for this
         * target.  If we did, this is a signal that
         * the target is refusing negotiation.
         */
        struct scb *scb;
        struct ahc_initiator_tinfo *tinfo;
        struct ahc_tmode_tstate *tstate;
        u_int scb_index;
        u_int last_msg;
        int   response = 0;

        scb_index = ahc_inb(ahc, SCB_TAG);
        scb = ahc_lookup_scb(ahc, scb_index);
        tinfo = ahc_fetch_transinfo(ahc, devinfo->channel,
                                    devinfo->our_scsiid,
                                    devinfo->target, &tstate);
        /* Might be necessary */
        last_msg = ahc_inb(ahc, LAST_MSG);

        if (ahc_sent_msg(ahc, AHCMSG_EXT, MSG_EXT_PPR, /*full*/FALSE)) {
                /*
                 * Target does not support the PPR message.
                 * Attempt to negotiate SPI-2 style.
                 */
                if (bootverbose) {
                        printf("(%s:%c:%d:%d): PPR Rejected. "
                               "Trying WDTR/SDTR\n",
                               ahc_name(ahc), devinfo->channel,
                               devinfo->target, devinfo->lun);
                }
                tinfo->goal.ppr_options = 0;
                tinfo->curr.transport_version = 2;
                tinfo->goal.transport_version = 2;
                ahc->msgout_index = 0;
                ahc->msgout_len = 0;
                ahc_build_transfer_msg(ahc, devinfo);
                ahc->msgout_index = 0;
                response = 1;
        } else if (ahc_sent_msg(ahc, AHCMSG_EXT, MSG_EXT_WDTR, /*full*/FALSE)) {

                /* note 8bit xfers */
                printf("(%s:%c:%d:%d): refuses WIDE negotiation.  Using "
                       "8bit transfers\n", ahc_name(ahc),
                       devinfo->channel, devinfo->target, devinfo->lun);
                ahc_set_width(ahc, devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                              AHC_TRANS_ACTIVE|AHC_TRANS_GOAL,
                              /*paused*/TRUE);
                /*
                 * No need to clear the sync rate.  If the target
                 * did not accept the command, our syncrate is
                 * unaffected.  If the target started the negotiation,
                 * but rejected our response, we already cleared the
                 * sync rate before sending our WDTR.
                 */
                if (tinfo->goal.offset != tinfo->curr.offset) {

                        /* Start the sync negotiation */
                        ahc->msgout_index = 0;
                        ahc->msgout_len = 0;
                        ahc_build_transfer_msg(ahc, devinfo);
                        ahc->msgout_index = 0;
                        response = 1;
                }
        } else if (ahc_sent_msg(ahc, AHCMSG_EXT, MSG_EXT_SDTR, /*full*/FALSE)) {
                /* note asynch xfers and clear flag */
                ahc_set_syncrate(ahc, devinfo, /*syncrate*/NULL, /*period*/0,
                                 /*offset*/0, /*ppr_options*/0,
                                 AHC_TRANS_ACTIVE|AHC_TRANS_GOAL,
                                 /*paused*/TRUE);
                printf("(%s:%c:%d:%d): refuses synchronous negotiation. "
                       "Using asynchronous transfers\n",
                       ahc_name(ahc), devinfo->channel,
                       devinfo->target, devinfo->lun);
        } else if ((scb->hscb->control & MSG_SIMPLE_TASK) != 0) {
                int tag_type;
                int mask;

                tag_type = (scb->hscb->control & MSG_SIMPLE_TASK);

                if (tag_type == MSG_SIMPLE_TASK) {
                        printf("(%s:%c:%d:%d): refuses tagged commands.  "
                               "Performing non-tagged I/O\n", ahc_name(ahc),
                               devinfo->channel, devinfo->target, devinfo->lun);
                        ahc_set_tags(ahc, scb->io_ctx, devinfo, AHC_QUEUE_NONE);
                        mask = ~0x23;
                } else {
                        printf("(%s:%c:%d:%d): refuses %s tagged commands.  "
                               "Performing simple queue tagged I/O only\n",
                               ahc_name(ahc), devinfo->channel, devinfo->target,
                               devinfo->lun, tag_type == MSG_ORDERED_TASK
                               ? "ordered" : "head of queue");
                        ahc_set_tags(ahc, scb->io_ctx, devinfo, AHC_QUEUE_BASIC);
                        mask = ~0x03;
                }

                /*
                 * Resend the identify for this CCB as the target
                 * may believe that the selection is invalid otherwise.
                 */
                ahc_outb(ahc, SCB_CONTROL,
                         ahc_inb(ahc, SCB_CONTROL) & mask);
                 scb->hscb->control &= mask;
                ahc_set_transaction_tag(scb, /*enabled*/FALSE,
                                        /*type*/MSG_SIMPLE_TASK);
                ahc_outb(ahc, MSG_OUT, MSG_IDENTIFYFLAG);
                ahc_assert_atn(ahc);

                /*
                 * This transaction is now at the head of
                 * the untagged queue for this target.
                 */
                if ((ahc->flags & AHC_SCB_BTT) == 0) {
                        struct scb_tailq *untagged_q;

                        untagged_q =
                            &(ahc->untagged_queues[devinfo->target_offset]);
                        TAILQ_INSERT_HEAD(untagged_q, scb, links.tqe);
                        scb->flags |= SCB_UNTAGGEDQ;
                }
                ahc_busy_tcl(ahc, BUILD_TCL(scb->hscb->scsiid, devinfo->lun),
                             scb->hscb->tag);

                /*
                 * Requeue all tagged commands for this target
                 * currently in our posession so they can be
                 * converted to untagged commands.
                 */
                ahc_search_qinfifo(ahc, SCB_GET_TARGET(ahc, scb),
                                   SCB_GET_CHANNEL(ahc, scb),
                                   SCB_GET_LUN(scb), /*tag*/SCB_LIST_NULL,
                                   ROLE_INITIATOR, CAM_REQUEUE_REQ,
                                   SEARCH_COMPLETE);
        } else {
                /*
                 * Otherwise, we ignore it.
                 */
                printf("%s:%c:%d: Message reject for %x -- ignored\n",
                       ahc_name(ahc), devinfo->channel, devinfo->target,
                       last_msg);
        }
        return (response);
}

/*
 * Process an ingnore wide residue message.
 */
static void
ahc_handle_ign_wide_residue(struct ahc_softc *ahc, struct ahc_devinfo *devinfo)
{
        u_int scb_index;
        struct scb *scb;

        scb_index = ahc_inb(ahc, SCB_TAG);
        scb = ahc_lookup_scb(ahc, scb_index);
        /*
         * XXX Actually check data direction in the sequencer?
         * Perhaps add datadir to some spare bits in the hscb?
         */
        if ((ahc_inb(ahc, SEQ_FLAGS) & DPHASE) == 0
         || ahc_get_transfer_dir(scb) != CAM_DIR_IN) {
                /*
                 * Ignore the message if we haven't
                 * seen an appropriate data phase yet.
                 */
        } else {
                /*
                 * If the residual occurred on the last
                 * transfer and the transfer request was
                 * expected to end on an odd count, do
                 * nothing.  Otherwise, subtract a byte
                 * and update the residual count accordingly.
                 */
                uint32_t sgptr;

                sgptr = ahc_inb(ahc, SCB_RESIDUAL_SGPTR);
                if ((sgptr & SG_LIST_NULL) != 0
                 && (ahc_inb(ahc, SCB_LUN) & SCB_XFERLEN_ODD) != 0) {
                        /*
                         * If the residual occurred on the last
                         * transfer and the transfer request was
                         * expected to end on an odd count, do
                         * nothing.
                         */
                } else {
                        struct ahc_dma_seg *sg;
                        uint32_t data_cnt;
                        uint32_t data_addr;
                        uint32_t sglen;

                        /* Pull in all of the sgptr */
                        sgptr = ahc_inl(ahc, SCB_RESIDUAL_SGPTR);
                        data_cnt = ahc_inl(ahc, SCB_RESIDUAL_DATACNT);

                        if ((sgptr & SG_LIST_NULL) != 0) {
                                /*
                                 * The residual data count is not updated
                                 * for the command run to completion case.
                                 * Explicitly zero the count.
                                 */
                                data_cnt &= ~AHC_SG_LEN_MASK;
                        }

                        data_addr = ahc_inl(ahc, SHADDR);

                        data_cnt += 1;
                        data_addr -= 1;
                        sgptr &= SG_PTR_MASK;

                        sg = ahc_sg_bus_to_virt(scb, sgptr);

                        /*
                         * The residual sg ptr points to the next S/G
                         * to load so we must go back one.
                         */
                        sg--;
                        sglen = ahc_le32toh(sg->len) & AHC_SG_LEN_MASK;
                        if (sg != scb->sg_list
                         && sglen < (data_cnt & AHC_SG_LEN_MASK)) {

                                sg--;
                                sglen = ahc_le32toh(sg->len);
                                /*
                                 * Preserve High Address and SG_LIST bits
                                 * while setting the count to 1.
                                 */
                                data_cnt = 1 | (sglen & (~AHC_SG_LEN_MASK));
                                data_addr = ahc_le32toh(sg->addr)
                                          + (sglen & AHC_SG_LEN_MASK) - 1;

                                /*
                                 * Increment sg so it points to the
                                 * "next" sg.
                                 */
                                sg++;
                                sgptr = ahc_sg_virt_to_bus(scb, sg);
                        }
                        ahc_outl(ahc, SCB_RESIDUAL_SGPTR, sgptr);
                        ahc_outl(ahc, SCB_RESIDUAL_DATACNT, data_cnt);
                        /*
                         * Toggle the "oddness" of the transfer length
                         * to handle this mid-transfer ignore wide
                         * residue.  This ensures that the oddness is
                         * correct for subsequent data transfers.
                         */
                        ahc_outb(ahc, SCB_LUN,
                                 ahc_inb(ahc, SCB_LUN) ^ SCB_XFERLEN_ODD);
                }
        }
}


/*
 * Reinitialize the data pointers for the active transfer
 * based on its current residual.
 */
static void
ahc_reinitialize_dataptrs(struct ahc_softc *ahc)
{
        struct         scb *scb;
        struct         ahc_dma_seg *sg;
        u_int         scb_index;
        uint32_t sgptr;
        uint32_t resid;
        uint32_t dataptr;

        scb_index = ahc_inb(ahc, SCB_TAG);
        scb = ahc_lookup_scb(ahc, scb_index);
        sgptr = (ahc_inb(ahc, SCB_RESIDUAL_SGPTR + 3) << 24)
              | (ahc_inb(ahc, SCB_RESIDUAL_SGPTR + 2) << 16)
              | (ahc_inb(ahc, SCB_RESIDUAL_SGPTR + 1) << 8)
              |        ahc_inb(ahc, SCB_RESIDUAL_SGPTR);

        sgptr &= SG_PTR_MASK;
        sg = ahc_sg_bus_to_virt(scb, sgptr);

        /* The residual sg_ptr always points to the next sg */
        sg--;

        resid = (ahc_inb(ahc, SCB_RESIDUAL_DATACNT + 2) << 16)
              | (ahc_inb(ahc, SCB_RESIDUAL_DATACNT + 1) << 8)
              | ahc_inb(ahc, SCB_RESIDUAL_DATACNT);

        dataptr = ahc_le32toh(sg->addr)
                + (ahc_le32toh(sg->len) & AHC_SG_LEN_MASK)
                - resid;
        if ((ahc->flags & AHC_39BIT_ADDRESSING) != 0) {
                u_int dscommand1;

                dscommand1 = ahc_inb(ahc, DSCOMMAND1);
                ahc_outb(ahc, DSCOMMAND1, dscommand1 | HADDLDSEL0);
                ahc_outb(ahc, HADDR,
                         (ahc_le32toh(sg->len) >> 24) & SG_HIGH_ADDR_BITS);
                ahc_outb(ahc, DSCOMMAND1, dscommand1);
        }
        ahc_outb(ahc, HADDR + 3, dataptr >> 24);
        ahc_outb(ahc, HADDR + 2, dataptr >> 16);
        ahc_outb(ahc, HADDR + 1, dataptr >> 8);
        ahc_outb(ahc, HADDR, dataptr);
        ahc_outb(ahc, HCNT + 2, resid >> 16);
        ahc_outb(ahc, HCNT + 1, resid >> 8);
        ahc_outb(ahc, HCNT, resid);
        if ((ahc->features & AHC_ULTRA2) == 0) {
                ahc_outb(ahc, STCNT + 2, resid >> 16);
                ahc_outb(ahc, STCNT + 1, resid >> 8);
                ahc_outb(ahc, STCNT, resid);
        }
}

/*
 * Handle the effects of issuing a bus device reset message.
 */
static void
ahc_handle_devreset(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                    cam_status status, char *message, int verbose_level)
{
#ifdef AHC_TARGET_MODE
        struct ahc_tmode_tstate* tstate;
        u_int lun;
#endif
        int found;

        found = ahc_abort_scbs(ahc, devinfo->target, devinfo->channel,
                               CAM_LUN_WILDCARD, SCB_LIST_NULL, devinfo->role,
                               status);

#ifdef AHC_TARGET_MODE
        /*
         * Send an immediate notify ccb to all target mord peripheral
         * drivers affected by this action.
         */
        tstate = ahc->enabled_targets[devinfo->our_scsiid];
        if (tstate != NULL) {
                for (lun = 0; lun < AHC_NUM_LUNS; lun++) {
                        struct ahc_tmode_lstate* lstate;

                        lstate = tstate->enabled_luns[lun];
                        if (lstate == NULL)
                                continue;

                        ahc_queue_lstate_event(ahc, lstate, devinfo->our_scsiid,
                                               MSG_BUS_DEV_RESET, /*arg*/0);
                        ahc_send_lstate_events(ahc, lstate);
                }
        }
#endif

        /*
         * Go back to async/narrow transfers and renegotiate.
         */
        ahc_set_width(ahc, devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                      AHC_TRANS_CUR, /*paused*/TRUE);
        ahc_set_syncrate(ahc, devinfo, /*syncrate*/NULL,
                         /*period*/0, /*offset*/0, /*ppr_options*/0,
                         AHC_TRANS_CUR, /*paused*/TRUE);
        
        if (status != CAM_SEL_TIMEOUT)
                ahc_send_async(ahc, devinfo->channel, devinfo->target,
                               CAM_LUN_WILDCARD, AC_SENT_BDR);

        if (message != NULL
         && (verbose_level <= bootverbose))
                printf("%s: %s on %c:%d. %d SCBs aborted\n", ahc_name(ahc),
                       message, devinfo->channel, devinfo->target, found);
}

#ifdef AHC_TARGET_MODE
static void
ahc_setup_target_msgin(struct ahc_softc *ahc, struct ahc_devinfo *devinfo,
                       struct scb *scb)
{

        /*              
         * To facilitate adding multiple messages together,
         * each routine should increment the index and len
         * variables instead of setting them explicitly.
         */             
        ahc->msgout_index = 0;
        ahc->msgout_len = 0;

        if (scb != NULL && (scb->flags & SCB_AUTO_NEGOTIATE) != 0)
                ahc_build_transfer_msg(ahc, devinfo);
        else
                panic("ahc_intr: AWAITING target message with no message");

        ahc->msgout_index = 0;
        ahc->msg_type = MSG_TYPE_TARGET_MSGIN;
}
#endif
/**************************** Initialization **********************************/
/*
 * Allocate a controller structure for a new device
 * and perform initial initializion.
 */
struct ahc_softc *
ahc_alloc(void *platform_arg, char *name)
{
        struct  ahc_softc *ahc;
        int        i;

#ifndef        __FreeBSD__
        ahc = malloc(sizeof(*ahc), M_DEVBUF, M_NOWAIT);
        if (!ahc) {
                printf("aic7xxx: cannot malloc softc!\n");
                free(name, M_DEVBUF);
                return NULL;
        }
#else
        ahc = device_get_softc((device_t)platform_arg);
#endif
        memset(ahc, 0, sizeof(*ahc));
        ahc->seep_config = malloc(sizeof(*ahc->seep_config),
                                  M_DEVBUF, M_NOWAIT);
        if (ahc->seep_config == NULL) {
#ifndef        __FreeBSD__
                free(ahc, M_DEVBUF);
#endif
                free(name, M_DEVBUF);
                return (NULL);
        }
        LIST_INIT(&ahc->pending_scbs);
        /* We don't know our unit number until the OSM sets it */
        ahc->name = name;
        ahc->unit = -1;
        ahc->description = NULL;
        ahc->channel = 'A';
        ahc->channel_b = 'B';
        ahc->chip = AHC_NONE;
        ahc->features = AHC_FENONE;
        ahc->bugs = AHC_BUGNONE;
        ahc->flags = AHC_FNONE;
        /*
         * Default to all error reporting enabled with the
         * sequencer operating at its fastest speed.
         * The bus attach code may modify this.
         */
        ahc->seqctl = FASTMODE;

        for (i = 0; i < AHC_NUM_TARGETS; i++)
                TAILQ_INIT(&ahc->untagged_queues[i]);
        if (ahc_platform_alloc(ahc, platform_arg) != 0) {
                ahc_free(ahc);
                ahc = NULL;
        }
        return (ahc);
}

int
ahc_softc_init(struct ahc_softc *ahc)
{

        /* The IRQMS bit is only valid on VL and EISA chips */
        if ((ahc->chip & AHC_PCI) == 0)
                ahc->unpause = ahc_inb(ahc, HCNTRL) & IRQMS;
        else
                ahc->unpause = 0;
        ahc->pause = ahc->unpause | PAUSE; 
        /* XXX The shared scb data stuff should be deprecated */
        if (ahc->scb_data == NULL) {
                ahc->scb_data = malloc(sizeof(*ahc->scb_data),
                                       M_DEVBUF, M_NOWAIT);
                if (ahc->scb_data == NULL)
                        return (ENOMEM);
                memset(ahc->scb_data, 0, sizeof(*ahc->scb_data));
        }

        return (0);
}

void
ahc_set_unit(struct ahc_softc *ahc, int unit)
{
        ahc->unit = unit;
}

void
ahc_set_name(struct ahc_softc *ahc, char *name)
{
        if (ahc->name != NULL)
                free(ahc->name, M_DEVBUF);
        ahc->name = name;
}

void
ahc_free(struct ahc_softc *ahc)
{
        int i;

        switch (ahc->init_level) {
        default:
        case 5:
                ahc_shutdown(ahc);
                /* FALLTHROUGH */
        case 4:
                ahc_dmamap_unload(ahc, ahc->shared_data_dmat,
                                  ahc->shared_data_dmamap);
                /* FALLTHROUGH */
        case 3:
                ahc_dmamem_free(ahc, ahc->shared_data_dmat, ahc->qoutfifo,
                                ahc->shared_data_dmamap);
                ahc_dmamap_destroy(ahc, ahc->shared_data_dmat,
                                   ahc->shared_data_dmamap);
                /* FALLTHROUGH */
        case 2:
                ahc_dma_tag_destroy(ahc, ahc->shared_data_dmat);
        case 1:
#ifndef __linux__
                ahc_dma_tag_destroy(ahc, ahc->buffer_dmat);
#endif
                break;
        case 0:
                break;
        }

#ifndef __linux__
        ahc_dma_tag_destroy(ahc, ahc->parent_dmat);
#endif
        ahc_platform_free(ahc);
        ahc_fini_scbdata(ahc);
        for (i = 0; i < AHC_NUM_TARGETS; i++) {
                struct ahc_tmode_tstate *tstate;

                tstate = ahc->enabled_targets[i];
                if (tstate != NULL) {
#ifdef AHC_TARGET_MODE
                        int j;

                        for (j = 0; j < AHC_NUM_LUNS; j++) {
                                struct ahc_tmode_lstate *lstate;

                                lstate = tstate->enabled_luns[j];
                                if (lstate != NULL) {
                                        xpt_free_path(lstate->path);
                                        free(lstate, M_DEVBUF);
                                }
                        }
#endif
                        free(tstate, M_DEVBUF);
                }
        }
#ifdef AHC_TARGET_MODE
        if (ahc->black_hole != NULL) {
                xpt_free_path(ahc->black_hole->path);
                free(ahc->black_hole, M_DEVBUF);
        }
#endif
        if (ahc->name != NULL)
                free(ahc->name, M_DEVBUF);
        if (ahc->seep_config != NULL)
                free(ahc->seep_config, M_DEVBUF);
#ifndef __FreeBSD__
        free(ahc, M_DEVBUF);
#endif
        return;
}

static void
ahc_shutdown(void *arg)
{
        struct        ahc_softc *ahc;
        int        i;

        ahc = (struct ahc_softc *)arg;

        /* This will reset most registers to 0, but not all */
        ahc_reset(ahc, /*reinit*/FALSE);
        ahc_outb(ahc, SCSISEQ, 0);
        ahc_outb(ahc, SXFRCTL0, 0);
        ahc_outb(ahc, DSPCISTATUS, 0);

        for (i = TARG_SCSIRATE; i < SCSICONF; i++)
                ahc_outb(ahc, i, 0);
}

/*
 * Reset the controller and record some information about it
 * that is only available just after a reset.  If "reinit" is
 * non-zero, this reset occured after initial configuration
 * and the caller requests that the chip be fully reinitialized
 * to a runable state.  Chip interrupts are *not* enabled after
 * a reinitialization.  The caller must enable interrupts via
 * ahc_intr_enable().
 */
int
ahc_reset(struct ahc_softc *ahc, int reinit)
{
        u_int        sblkctl;
        u_int        sxfrctl1_a, sxfrctl1_b;
        int        error;
        int        wait;
        
        /*
         * Preserve the value of the SXFRCTL1 register for all channels.
         * It contains settings that affect termination and we don't want
         * to disturb the integrity of the bus.
         */
        ahc_pause(ahc);
        sxfrctl1_b = 0;
        if ((ahc->chip & AHC_CHIPID_MASK) == AHC_AIC7770) {
                u_int sblkctl;

                /*
                 * Save channel B's settings in case this chip
                 * is setup for TWIN channel operation.
                 */
                sblkctl = ahc_inb(ahc, SBLKCTL);
                ahc_outb(ahc, SBLKCTL, sblkctl | SELBUSB);
                sxfrctl1_b = ahc_inb(ahc, SXFRCTL1);
                ahc_outb(ahc, SBLKCTL, sblkctl & ~SELBUSB);
        }
        sxfrctl1_a = ahc_inb(ahc, SXFRCTL1);

        ahc_outb(ahc, HCNTRL, CHIPRST | ahc->pause);

        /*
         * Ensure that the reset has finished.  We delay 1000us
         * prior to reading the register to make sure the chip
         * has sufficiently completed its reset to handle register
         * accesses.
         */
        wait = 1000;
        do {
                ahc_delay(1000);
        } while (--wait && !(ahc_inb(ahc, HCNTRL) & CHIPRSTACK));

        if (wait == 0) {
                printf("%s: WARNING - Failed chip reset!  "
                       "Trying to initialize anyway.\n", ahc_name(ahc));
        }
        ahc_outb(ahc, HCNTRL, ahc->pause);

        /* Determine channel configuration */
        sblkctl = ahc_inb(ahc, SBLKCTL) & (SELBUSB|SELWIDE);
        /* No Twin Channel PCI cards */
        if ((ahc->chip & AHC_PCI) != 0)
                sblkctl &= ~SELBUSB;
        switch (sblkctl) {
        case 0:
                /* Single Narrow Channel */
                break;
        case 2:
                /* Wide Channel */
                ahc->features |= AHC_WIDE;
                break;
        case 8:
                /* Twin Channel */
                ahc->features |= AHC_TWIN;
                break;
        default:
                printf(" Unsupported adapter type.  Ignoring\n");
                return(-1);
        }

        /*
         * Reload sxfrctl1.
         *
         * We must always initialize STPWEN to 1 before we
         * restore the saved values.  STPWEN is initialized
         * to a tri-state condition which can only be cleared
         * by turning it on.
         */
        if ((ahc->features & AHC_TWIN) != 0) {
                u_int sblkctl;

                sblkctl = ahc_inb(ahc, SBLKCTL);
                ahc_outb(ahc, SBLKCTL, sblkctl | SELBUSB);
                ahc_outb(ahc, SXFRCTL1, sxfrctl1_b);
                ahc_outb(ahc, SBLKCTL, sblkctl & ~SELBUSB);
        }
        ahc_outb(ahc, SXFRCTL1, sxfrctl1_a);

        error = 0;
        if (reinit != 0)
                /*
                 * If a recovery action has forced a chip reset,
                 * re-initialize the chip to our liking.
                 */
                error = ahc->bus_chip_init(ahc);
#ifdef AHC_DUMP_SEQ
        else 
                ahc_dumpseq(ahc);
#endif

        return (error);
}

/*
 * Determine the number of SCBs available on the controller
 */
int
ahc_probe_scbs(struct ahc_softc *ahc) {
        int i;

        for (i = 0; i < AHC_SCB_MAX; i++) {

                ahc_outb(ahc, SCBPTR, i);
                ahc_outb(ahc, SCB_BASE, i);
                if (ahc_inb(ahc, SCB_BASE) != i)
                        break;
                ahc_outb(ahc, SCBPTR, 0);
                if (ahc_inb(ahc, SCB_BASE) != 0)
                        break;
        }
        return (i);
}

static void
ahc_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error) 
{
        dma_addr_t *baddr;

        baddr = (dma_addr_t *)arg;
        *baddr = segs->ds_addr;
}

static void
ahc_build_free_scb_list(struct ahc_softc *ahc)
{
        int scbsize;
        int i;

        scbsize = 32;
        if ((ahc->flags & AHC_LSCBS_ENABLED) != 0)
                scbsize = 64;

        for (i = 0; i < ahc->scb_data->maxhscbs; i++) {
                int j;

                ahc_outb(ahc, SCBPTR, i);

                /*
                 * Touch all SCB bytes to avoid parity errors
                 * should one of our debugging routines read
                 * an otherwise uninitiatlized byte.
                 */
                for (j = 0; j < scbsize; j++)
                        ahc_outb(ahc, SCB_BASE+j, 0xFF);

                /* Clear the control byte. */
                ahc_outb(ahc, SCB_CONTROL, 0);

                /* Set the next pointer */
                if ((ahc->flags & AHC_PAGESCBS) != 0)
                        ahc_outb(ahc, SCB_NEXT, i+1);
                else 
                        ahc_outb(ahc, SCB_NEXT, SCB_LIST_NULL);

                /* Make the tag number, SCSIID, and lun invalid */
                ahc_outb(ahc, SCB_TAG, SCB_LIST_NULL);
                ahc_outb(ahc, SCB_SCSIID, 0xFF);
                ahc_outb(ahc, SCB_LUN, 0xFF);
        }

        if ((ahc->flags & AHC_PAGESCBS) != 0) {
                /* SCB 0 heads the free list. */
                ahc_outb(ahc, FREE_SCBH, 0);
        } else {
                /* No free list. */
                ahc_outb(ahc, FREE_SCBH, SCB_LIST_NULL);
        }

        /* Make sure that the last SCB terminates the free list */
        ahc_outb(ahc, SCBPTR, i-1);
        ahc_outb(ahc, SCB_NEXT, SCB_LIST_NULL);
}

static int
ahc_init_scbdata(struct ahc_softc *ahc)
{
        struct scb_data *scb_data;

        scb_data = ahc->scb_data;
        SLIST_INIT(&scb_data->free_scbs);
        SLIST_INIT(&scb_data->sg_maps);

        /* Allocate SCB resources */
        scb_data->scbarray =
            (struct scb *)malloc(sizeof(struct scb) * AHC_SCB_MAX_ALLOC,
                                 M_DEVBUF, M_NOWAIT);
        if (scb_data->scbarray == NULL)
                return (ENOMEM);
        memset(scb_data->scbarray, 0, sizeof(struct scb) * AHC_SCB_MAX_ALLOC);

        /* Determine the number of hardware SCBs and initialize them */

        scb_data->maxhscbs = ahc_probe_scbs(ahc);
        if (ahc->scb_data->maxhscbs == 0) {
                printf("%s: No SCB space found\n", ahc_name(ahc));
                return (ENXIO);
        }

        /*
         * Create our DMA tags.  These tags define the kinds of device
         * accessible memory allocations and memory mappings we will
         * need to perform during normal operation.
         *
         * Unless we need to further restrict the allocation, we rely
         * on the restrictions of the parent dmat, hence the common
         * use of MAXADDR and MAXSIZE.
         */

        /* DMA tag for our hardware scb structures */
        if (ahc_dma_tag_create(ahc, ahc->parent_dmat, /*alignment*/1,
                               /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                               /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                               /*highaddr*/BUS_SPACE_MAXADDR,
                               /*filter*/NULL, /*filterarg*/NULL,
                               AHC_SCB_MAX_ALLOC * sizeof(struct hardware_scb),
                               /*nsegments*/1,
                               /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                               /*flags*/0, &scb_data->hscb_dmat) != 0) {
                goto error_exit;
        }

        scb_data->init_level++;

        /* Allocation for our hscbs */
        if (ahc_dmamem_alloc(ahc, scb_data->hscb_dmat,
                             (void **)&scb_data->hscbs,
                             BUS_DMA_NOWAIT, &scb_data->hscb_dmamap) != 0) {
                goto error_exit;
        }

        scb_data->init_level++;

        /* And permanently map them */
        ahc_dmamap_load(ahc, scb_data->hscb_dmat, scb_data->hscb_dmamap,
                        scb_data->hscbs,
                        AHC_SCB_MAX_ALLOC * sizeof(struct hardware_scb),
                        ahc_dmamap_cb, &scb_data->hscb_busaddr, /*flags*/0);

        scb_data->init_level++;

        /* DMA tag for our sense buffers */
        if (ahc_dma_tag_create(ahc, ahc->parent_dmat, /*alignment*/1,
                               /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                               /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                               /*highaddr*/BUS_SPACE_MAXADDR,
                               /*filter*/NULL, /*filterarg*/NULL,
                               AHC_SCB_MAX_ALLOC * sizeof(struct scsi_sense_data),
                               /*nsegments*/1,
                               /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                               /*flags*/0, &scb_data->sense_dmat) != 0) {
                goto error_exit;
        }

        scb_data->init_level++;

        /* Allocate them */
        if (ahc_dmamem_alloc(ahc, scb_data->sense_dmat,
                             (void **)&scb_data->sense,
                             BUS_DMA_NOWAIT, &scb_data->sense_dmamap) != 0) {
                goto error_exit;
        }

        scb_data->init_level++;

        /* And permanently map them */
        ahc_dmamap_load(ahc, scb_data->sense_dmat, scb_data->sense_dmamap,
                        scb_data->sense,
                        AHC_SCB_MAX_ALLOC * sizeof(struct scsi_sense_data),
                        ahc_dmamap_cb, &scb_data->sense_busaddr, /*flags*/0);

        scb_data->init_level++;

        /* DMA tag for our S/G structures.  We allocate in page sized chunks */
        if (ahc_dma_tag_create(ahc, ahc->parent_dmat, /*alignment*/8,
                               /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                               /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                               /*highaddr*/BUS_SPACE_MAXADDR,
                               /*filter*/NULL, /*filterarg*/NULL,
                               PAGE_SIZE, /*nsegments*/1,
                               /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                               /*flags*/0, &scb_data->sg_dmat) != 0) {
                goto error_exit;
        }

        scb_data->init_level++;

        /* Perform initial CCB allocation */
        memset(scb_data->hscbs, 0,
               AHC_SCB_MAX_ALLOC * sizeof(struct hardware_scb));
        ahc_alloc_scbs(ahc);

        if (scb_data->numscbs == 0) {
                printf("%s: ahc_init_scbdata - "
                       "Unable to allocate initial scbs\n",
                       ahc_name(ahc));
                goto error_exit;
        }

        /*
         * Reserve the next queued SCB.
         */
        ahc->next_queued_scb = ahc_get_scb(ahc);

        /*
         * Note that we were successfull
         */
        return (0); 

error_exit:

        return (ENOMEM);
}

static void
ahc_fini_scbdata(struct ahc_softc *ahc)
{
        struct scb_data *scb_data;

        scb_data = ahc->scb_data;
        if (scb_data == NULL)
                return;

        switch (scb_data->init_level) {
        default:
        case 7:
        {
                struct sg_map_node *sg_map;

                while ((sg_map = SLIST_FIRST(&scb_data->sg_maps))!= NULL) {
                        SLIST_REMOVE_HEAD(&scb_data->sg_maps, links);
                        ahc_dmamap_unload(ahc, scb_data->sg_dmat,
                                          sg_map->sg_dmamap);
                        ahc_dmamem_free(ahc, scb_data->sg_dmat,
                                        sg_map->sg_vaddr,
                                        sg_map->sg_dmamap);
                        free(sg_map, M_DEVBUF);
                }
                ahc_dma_tag_destroy(ahc, scb_data->sg_dmat);
        }
        case 6:
                ahc_dmamap_unload(ahc, scb_data->sense_dmat,
                                  scb_data->sense_dmamap);
        case 5:
                ahc_dmamem_free(ahc, scb_data->sense_dmat, scb_data->sense,
                                scb_data->sense_dmamap);
                ahc_dmamap_destroy(ahc, scb_data->sense_dmat,
                                   scb_data->sense_dmamap);
        case 4:
                ahc_dma_tag_destroy(ahc, scb_data->sense_dmat);
        case 3:
                ahc_dmamap_unload(ahc, scb_data->hscb_dmat,
                                  scb_data->hscb_dmamap);
        case 2:
                ahc_dmamem_free(ahc, scb_data->hscb_dmat, scb_data->hscbs,
                                scb_data->hscb_dmamap);
                ahc_dmamap_destroy(ahc, scb_data->hscb_dmat,
                                   scb_data->hscb_dmamap);
        case 1:
                ahc_dma_tag_destroy(ahc, scb_data->hscb_dmat);
                break;
        case 0:
                break;
        }
        if (scb_data->scbarray != NULL)
                free(scb_data->scbarray, M_DEVBUF);
}

static void
ahc_alloc_scbs(struct ahc_softc *ahc)
{
        struct scb_data *scb_data;
        struct scb *next_scb;
        struct sg_map_node *sg_map;
        dma_addr_t physaddr;
        struct ahc_dma_seg *segs;
        int newcount;
        int i;

        scb_data = ahc->scb_data;
        if (scb_data->numscbs >= AHC_SCB_MAX_ALLOC)
                /* Can't allocate any more */
                return;

        next_scb = &scb_data->scbarray[scb_data->numscbs];

        sg_map = malloc(sizeof(*sg_map), M_DEVBUF, M_NOWAIT);

        if (sg_map == NULL)
                return;

        /* Allocate S/G space for the next batch of SCBS */
        if (ahc_dmamem_alloc(ahc, scb_data->sg_dmat,
                             (void **)&sg_map->sg_vaddr,
                             BUS_DMA_NOWAIT, &sg_map->sg_dmamap) != 0) {
                free(sg_map, M_DEVBUF);
                return;
        }

        SLIST_INSERT_HEAD(&scb_data->sg_maps, sg_map, links);

        ahc_dmamap_load(ahc, scb_data->sg_dmat, sg_map->sg_dmamap,
                        sg_map->sg_vaddr, PAGE_SIZE, ahc_dmamap_cb,
                        &sg_map->sg_physaddr, /*flags*/0);

        segs = sg_map->sg_vaddr;
        physaddr = sg_map->sg_physaddr;

        newcount = (PAGE_SIZE / (AHC_NSEG * sizeof(struct ahc_dma_seg)));
        newcount = min(newcount, (AHC_SCB_MAX_ALLOC - scb_data->numscbs));
        for (i = 0; i < newcount; i++) {
                struct scb_platform_data *pdata;
#ifndef __linux__
                int error;
#endif
                pdata = (struct scb_platform_data *)malloc(sizeof(*pdata),
                                                           M_DEVBUF, M_NOWAIT);
                if (pdata == NULL)
                        break;
                next_scb->platform_data = pdata;
                next_scb->sg_map = sg_map;
                next_scb->sg_list = segs;
                /*
                 * The sequencer always starts with the second entry.
                 * The first entry is embedded in the scb.
                 */
                next_scb->sg_list_phys = physaddr + sizeof(struct ahc_dma_seg);
                next_scb->ahc_softc = ahc;
                next_scb->flags = SCB_FREE;
#ifndef __linux__
                error = ahc_dmamap_create(ahc, ahc->buffer_dmat, /*flags*/0,
                                          &next_scb->dmamap);
                if (error != 0)
                        break;
#endif
                next_scb->hscb = &scb_data->hscbs[scb_data->numscbs];
                next_scb->hscb->tag = ahc->scb_data->numscbs;
                SLIST_INSERT_HEAD(&ahc->scb_data->free_scbs,
                                  next_scb, links.sle);
                segs += AHC_NSEG;
                physaddr += (AHC_NSEG * sizeof(struct ahc_dma_seg));
                next_scb++;
                ahc->scb_data->numscbs++;
        }
}

void
ahc_controller_info(struct ahc_softc *ahc, char *buf)
{
        int len;

        len = sprintf(buf, "%s: ", ahc_chip_names[ahc->chip & AHC_CHIPID_MASK]);
        buf += len;
        if ((ahc->features & AHC_TWIN) != 0)
                 len = sprintf(buf, "Twin Channel, A SCSI Id=%d, "
                              "B SCSI Id=%d, primary %c, ",
                              ahc->our_id, ahc->our_id_b,
                              (ahc->flags & AHC_PRIMARY_CHANNEL) + 'A');
        else {
                const char *speed;
                const char *type;

                speed = "";
                if ((ahc->features & AHC_ULTRA) != 0) {
                        speed = "Ultra ";
                } else if ((ahc->features & AHC_DT) != 0) {
                        speed = "Ultra160 ";
                } else if ((ahc->features & AHC_ULTRA2) != 0) {
                        speed = "Ultra2 ";
                }
                if ((ahc->features & AHC_WIDE) != 0) {
                        type = "Wide";
                } else {
                        type = "Single";
                }
                len = sprintf(buf, "%s%s Channel %c, SCSI Id=%d, ",
                              speed, type, ahc->channel, ahc->our_id);
        }
        buf += len;

        if ((ahc->flags & AHC_PAGESCBS) != 0)
                sprintf(buf, "%d/%d SCBs",
                        ahc->scb_data->maxhscbs, AHC_MAX_QUEUE);
        else
                sprintf(buf, "%d SCBs", ahc->scb_data->maxhscbs);
}

int
ahc_chip_init(struct ahc_softc *ahc)
{
        int         term;
        int         error;
        u_int         i;
        u_int         scsi_conf;
        u_int         scsiseq_template;
        uint32_t physaddr;

        ahc_outb(ahc, SEQ_FLAGS, 0);
        ahc_outb(ahc, SEQ_FLAGS2, 0);

        /* Set the SCSI Id, SXFRCTL0, SXFRCTL1, and SIMODE1, for both channels*/
        if (ahc->features & AHC_TWIN) {

                /*
                 * Setup Channel B first.
                 */
                ahc_outb(ahc, SBLKCTL, ahc_inb(ahc, SBLKCTL) | SELBUSB);
                term = (ahc->flags & AHC_TERM_ENB_B) != 0 ? STPWEN : 0;
                ahc_outb(ahc, SCSIID, ahc->our_id_b);
                scsi_conf = ahc_inb(ahc, SCSICONF + 1);
                ahc_outb(ahc, SXFRCTL1, (scsi_conf & (ENSPCHK|STIMESEL))
                                        |term|ahc->seltime_b|ENSTIMER|ACTNEGEN);
                if ((ahc->features & AHC_ULTRA2) != 0)
                        ahc_outb(ahc, SIMODE0, ahc_inb(ahc, SIMODE0)|ENIOERR);
                ahc_outb(ahc, SIMODE1, ENSELTIMO|ENSCSIRST|ENSCSIPERR);
                ahc_outb(ahc, SXFRCTL0, DFON|SPIOEN);

                /* Select Channel A */
                ahc_outb(ahc, SBLKCTL, ahc_inb(ahc, SBLKCTL) & ~SELBUSB);
        }
        term = (ahc->flags & AHC_TERM_ENB_A) != 0 ? STPWEN : 0;
        if ((ahc->features & AHC_ULTRA2) != 0)
                ahc_outb(ahc, SCSIID_ULTRA2, ahc->our_id);
        else
                ahc_outb(ahc, SCSIID, ahc->our_id);
        scsi_conf = ahc_inb(ahc, SCSICONF);
        ahc_outb(ahc, SXFRCTL1, (scsi_conf & (ENSPCHK|STIMESEL))
                                |term|ahc->seltime
                                |ENSTIMER|ACTNEGEN);
        if ((ahc->features & AHC_ULTRA2) != 0)
                ahc_outb(ahc, SIMODE0, ahc_inb(ahc, SIMODE0)|ENIOERR);
        ahc_outb(ahc, SIMODE1, ENSELTIMO|ENSCSIRST|ENSCSIPERR);
        ahc_outb(ahc, SXFRCTL0, DFON|SPIOEN);

        /* There are no untagged SCBs active yet. */
        for (i = 0; i < 16; i++) {
                ahc_unbusy_tcl(ahc, BUILD_TCL(i << 4, 0));
                if ((ahc->flags & AHC_SCB_BTT) != 0) {
                        int lun;

                        /*
                         * The SCB based BTT allows an entry per
                         * target and lun pair.
                         */
                        for (lun = 1; lun < AHC_NUM_LUNS; lun++)
                                ahc_unbusy_tcl(ahc, BUILD_TCL(i << 4, lun));
                }
        }

        /* All of our queues are empty */
        for (i = 0; i < 256; i++)
                ahc->qoutfifo[i] = SCB_LIST_NULL;
        ahc_sync_qoutfifo(ahc, BUS_DMASYNC_PREREAD);

        for (i = 0; i < 256; i++)
                ahc->qinfifo[i] = SCB_LIST_NULL;

        if ((ahc->features & AHC_MULTI_TID) != 0) {
                ahc_outb(ahc, TARGID, 0);
                ahc_outb(ahc, TARGID + 1, 0);
        }

        /*
         * Tell the sequencer where it can find our arrays in memory.
         */
        physaddr = ahc->scb_data->hscb_busaddr;
        ahc_outb(ahc, HSCB_ADDR, physaddr & 0xFF);
        ahc_outb(ahc, HSCB_ADDR + 1, (physaddr >> 8) & 0xFF);
        ahc_outb(ahc, HSCB_ADDR + 2, (physaddr >> 16) & 0xFF);
        ahc_outb(ahc, HSCB_ADDR + 3, (physaddr >> 24) & 0xFF);

        physaddr = ahc->shared_data_busaddr;
        ahc_outb(ahc, SHARED_DATA_ADDR, physaddr & 0xFF);
        ahc_outb(ahc, SHARED_DATA_ADDR + 1, (physaddr >> 8) & 0xFF);
        ahc_outb(ahc, SHARED_DATA_ADDR + 2, (physaddr >> 16) & 0xFF);
        ahc_outb(ahc, SHARED_DATA_ADDR + 3, (physaddr >> 24) & 0xFF);

        /*
         * Initialize the group code to command length table.
         * This overrides the values in TARG_SCSIRATE, so only
         * setup the table after we have processed that information.
         */
        ahc_outb(ahc, CMDSIZE_TABLE, 5);
        ahc_outb(ahc, CMDSIZE_TABLE + 1, 9);
        ahc_outb(ahc, CMDSIZE_TABLE + 2, 9);
        ahc_outb(ahc, CMDSIZE_TABLE + 3, 0);
        ahc_outb(ahc, CMDSIZE_TABLE + 4, 15);
        ahc_outb(ahc, CMDSIZE_TABLE + 5, 11);
        ahc_outb(ahc, CMDSIZE_TABLE + 6, 0);
        ahc_outb(ahc, CMDSIZE_TABLE + 7, 0);
                
        if ((ahc->features & AHC_HS_MAILBOX) != 0)
                ahc_outb(ahc, HS_MAILBOX, 0);

        /* Tell the sequencer of our initial queue positions */
        if ((ahc->features & AHC_TARGETMODE) != 0) {
                ahc->tqinfifonext = 1;
                ahc_outb(ahc, KERNEL_TQINPOS, ahc->tqinfifonext - 1);
                ahc_outb(ahc, TQINPOS, ahc->tqinfifonext);
        }
        ahc->qinfifonext = 0;
        ahc->qoutfifonext = 0;
        if ((ahc->features & AHC_QUEUE_REGS) != 0) {
                ahc_outb(ahc, QOFF_CTLSTA, SCB_QSIZE_256);
                ahc_outb(ahc, HNSCB_QOFF, ahc->qinfifonext);
                ahc_outb(ahc, SNSCB_QOFF, ahc->qinfifonext);
                ahc_outb(ahc, SDSCB_QOFF, 0);
        } else {
                ahc_outb(ahc, KERNEL_QINPOS, ahc->qinfifonext);
                ahc_outb(ahc, QINPOS, ahc->qinfifonext);
                ahc_outb(ahc, QOUTPOS, ahc->qoutfifonext);
        }

        /* We don't have any waiting selections */
        ahc_outb(ahc, WAITING_SCBH, SCB_LIST_NULL);

        /* Our disconnection list is empty too */
        ahc_outb(ahc, DISCONNECTED_SCBH, SCB_LIST_NULL);

        /* Message out buffer starts empty */
        ahc_outb(ahc, MSG_OUT, MSG_NOOP);

        /*
         * Setup the allowed SCSI Sequences based on operational mode.
         * If we are a target, we'll enalbe select in operations once
         * we've had a lun enabled.
         */
        scsiseq_template = ENSELO|ENAUTOATNO|ENAUTOATNP;
        if ((ahc->flags & AHC_INITIATORROLE) != 0)
                scsiseq_template |= ENRSELI;
        ahc_outb(ahc, SCSISEQ_TEMPLATE, scsiseq_template);

        /* Initialize our list of free SCBs. */
        ahc_build_free_scb_list(ahc);

        /*
         * Tell the sequencer which SCB will be the next one it receives.
         */
        ahc_outb(ahc, NEXT_QUEUED_SCB, ahc->next_queued_scb->hscb->tag);

        /*
         * Load the Sequencer program and Enable the adapter
         * in "fast" mode.
         */
        if (bootverbose)
                printf("%s: Downloading Sequencer Program...",
                       ahc_name(ahc));

        error = ahc_loadseq(ahc);
        if (error != 0)
                return (error);

        if ((ahc->features & AHC_ULTRA2) != 0) {
                int wait;

                /*
                 * Wait for up to 500ms for our transceivers
                 * to settle.  If the adapter does not have
                 * a cable attached, the transceivers may
                 * never settle, so don't complain if we
                 * fail here.
                 */
                for (wait = 5000;
                     (ahc_inb(ahc, SBLKCTL) & (ENAB40|ENAB20)) == 0 && wait;
                     wait--)
                        ahc_delay(100);
        }
        ahc_restart(ahc);
        return (0);
}

/*
 * Start the board, ready for normal operation
 */
int
ahc_init(struct ahc_softc *ahc)
{
        int         max_targ;
        u_int         i;
        u_int         scsi_conf;
        u_int         ultraenb;
        u_int         discenable;
        u_int         tagenable;
        size_t         driver_data_size;

#ifdef AHC_DEBUG
        if ((ahc_debug & AHC_DEBUG_SEQUENCER) != 0)
                ahc->flags |= AHC_SEQUENCER_DEBUG;
#endif

#ifdef AHC_PRINT_SRAM
        printf("Scratch Ram:");
        for (i = 0x20; i < 0x5f; i++) {
                if (((i % 8) == 0) && (i != 0)) {
                        printf ("\n              ");
                }
                printf (" 0x%x", ahc_inb(ahc, i));
        }
        if ((ahc->features & AHC_MORE_SRAM) != 0) {
                for (i = 0x70; i < 0x7f; i++) {
                        if (((i % 8) == 0) && (i != 0)) {
                                printf ("\n              ");
                        }
                        printf (" 0x%x", ahc_inb(ahc, i));
                }
        }
        printf ("\n");
        /*
         * Reading uninitialized scratch ram may
         * generate parity errors.
         */
        ahc_outb(ahc, CLRINT, CLRPARERR);
        ahc_outb(ahc, CLRINT, CLRBRKADRINT);
#endif
        max_targ = 15;

        /*
         * Assume we have a board at this stage and it has been reset.
         */
        if ((ahc->flags & AHC_USEDEFAULTS) != 0)
                ahc->our_id = ahc->our_id_b = 7;
        
        /*
         * Default to allowing initiator operations.
         */
        ahc->flags |= AHC_INITIATORROLE;

        /*
         * Only allow target mode features if this unit has them enabled.
         */
        if ((AHC_TMODE_ENABLE & (0x1 << ahc->unit)) == 0)
                ahc->features &= ~AHC_TARGETMODE;

#ifndef __linux__
        /* DMA tag for mapping buffers into device visible space. */
        if (ahc_dma_tag_create(ahc, ahc->parent_dmat, /*alignment*/1,
                               /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                               /*lowaddr*/ahc->flags & AHC_39BIT_ADDRESSING
                                        ? (dma_addr_t)0x7FFFFFFFFFULL
                                        : BUS_SPACE_MAXADDR_32BIT,
                               /*highaddr*/BUS_SPACE_MAXADDR,
                               /*filter*/NULL, /*filterarg*/NULL,
                               /*maxsize*/(AHC_NSEG - 1) * PAGE_SIZE,
                               /*nsegments*/AHC_NSEG,
                               /*maxsegsz*/AHC_MAXTRANSFER_SIZE,
                               /*flags*/BUS_DMA_ALLOCNOW,
                               &ahc->buffer_dmat) != 0) {
                return (ENOMEM);
        }
#endif

        ahc->init_level++;

        /*
         * DMA tag for our command fifos and other data in system memory
         * the card's sequencer must be able to access.  For initiator
         * roles, we need to allocate space for the qinfifo and qoutfifo.
         * The qinfifo and qoutfifo are composed of 256 1 byte elements. 
         * When providing for the target mode role, we must additionally
         * provide space for the incoming target command fifo and an extra
         * byte to deal with a dma bug in some chip versions.
         */
        driver_data_size = 2 * 256 * sizeof(uint8_t);
        if ((ahc->features & AHC_TARGETMODE) != 0)
                driver_data_size += AHC_TMODE_CMDS * sizeof(struct target_cmd)
                                 + /*DMA WideOdd Bug Buffer*/1;
        if (ahc_dma_tag_create(ahc, ahc->parent_dmat, /*alignment*/1,
                               /*boundary*/BUS_SPACE_MAXADDR_32BIT + 1,
                               /*lowaddr*/BUS_SPACE_MAXADDR_32BIT,
                               /*highaddr*/BUS_SPACE_MAXADDR,
                               /*filter*/NULL, /*filterarg*/NULL,
                               driver_data_size,
                               /*nsegments*/1,
                               /*maxsegsz*/BUS_SPACE_MAXSIZE_32BIT,
                               /*flags*/0, &ahc->shared_data_dmat) != 0) {
                return (ENOMEM);
        }

        ahc->init_level++;

        /* Allocation of driver data */
        if (ahc_dmamem_alloc(ahc, ahc->shared_data_dmat,
                             (void **)&ahc->qoutfifo,
                             BUS_DMA_NOWAIT, &ahc->shared_data_dmamap) != 0) {
                return (ENOMEM);
        }

        ahc->init_level++;

        /* And permanently map it in */
        ahc_dmamap_load(ahc, ahc->shared_data_dmat, ahc->shared_data_dmamap,
                        ahc->qoutfifo, driver_data_size, ahc_dmamap_cb,
                        &ahc->shared_data_busaddr, /*flags*/0);

        if ((ahc->features & AHC_TARGETMODE) != 0) {
                ahc->targetcmds = (struct target_cmd *)ahc->qoutfifo;
                ahc->qoutfifo = (uint8_t *)&ahc->targetcmds[AHC_TMODE_CMDS];
                ahc->dma_bug_buf = ahc->shared_data_busaddr
                                 + driver_data_size - 1;
                /* All target command blocks start out invalid. */
                for (i = 0; i < AHC_TMODE_CMDS; i++)
                        ahc->targetcmds[i].cmd_valid = 0;
                ahc_sync_tqinfifo(ahc, BUS_DMASYNC_PREREAD);
                ahc->qoutfifo = (uint8_t *)&ahc->targetcmds[256];
        }
        ahc->qinfifo = &ahc->qoutfifo[256];

        ahc->init_level++;

        /* Allocate SCB data now that buffer_dmat is initialized */
        if (ahc->scb_data->maxhscbs == 0)
                if (ahc_init_scbdata(ahc) != 0)
                        return (ENOMEM);

        /*
         * Allocate a tstate to house information for our
         * initiator presence on the bus as well as the user
         * data for any target mode initiator.
         */
        if (ahc_alloc_tstate(ahc, ahc->our_id, 'A') == NULL) {
                printf("%s: unable to allocate ahc_tmode_tstate.  "
                       "Failing attach\n", ahc_name(ahc));
                return (ENOMEM);
        }

        if ((ahc->features & AHC_TWIN) != 0) {
                if (ahc_alloc_tstate(ahc, ahc->our_id_b, 'B') == NULL) {
                        printf("%s: unable to allocate ahc_tmode_tstate.  "
                               "Failing attach\n", ahc_name(ahc));
                        return (ENOMEM);
                }
        }

        if (ahc->scb_data->maxhscbs < AHC_SCB_MAX_ALLOC) {
                ahc->flags |= AHC_PAGESCBS;
        } else {
                ahc->flags &= ~AHC_PAGESCBS;
        }

#ifdef AHC_DEBUG
        if (ahc_debug & AHC_SHOW_MISC) {
                printf("%s: hardware scb %u bytes; kernel scb %u bytes; "
                       "ahc_dma %u bytes\n",
                        ahc_name(ahc),
                        (u_int)sizeof(struct hardware_scb),
                        (u_int)sizeof(struct scb),
                        (u_int)sizeof(struct ahc_dma_seg));
        }
#endif /* AHC_DEBUG */

        /*
         * Look at the information that board initialization or
         * the board bios has left us.
         */
        if (ahc->features & AHC_TWIN) {
                scsi_conf = ahc_inb(ahc, SCSICONF + 1);
                if ((scsi_conf & RESET_SCSI) != 0
                 && (ahc->flags & AHC_INITIATORROLE) != 0)
                        ahc->flags |= AHC_RESET_BUS_B;
        }

        scsi_conf = ahc_inb(ahc, SCSICONF);
        if ((scsi_conf & RESET_SCSI) != 0
         && (ahc->flags & AHC_INITIATORROLE) != 0)
                ahc->flags |= AHC_RESET_BUS_A;

        ultraenb = 0;        
        tagenable = ALL_TARGETS_MASK;

        /* Grab the disconnection disable table and invert it for our needs */
        if ((ahc->flags & AHC_USEDEFAULTS) != 0) {
                printf("%s: Host Adapter Bios disabled.  Using default SCSI "
                        "device parameters\n", ahc_name(ahc));
                ahc->flags |= AHC_EXTENDED_TRANS_A|AHC_EXTENDED_TRANS_B|
                              AHC_TERM_ENB_A|AHC_TERM_ENB_B;
                discenable = ALL_TARGETS_MASK;
                if ((ahc->features & AHC_ULTRA) != 0)
                        ultraenb = ALL_TARGETS_MASK;
        } else {
                discenable = ~((ahc_inb(ahc, DISC_DSB + 1) << 8)
                           | ahc_inb(ahc, DISC_DSB));
                if ((ahc->features & (AHC_ULTRA|AHC_ULTRA2)) != 0)
                        ultraenb = (ahc_inb(ahc, ULTRA_ENB + 1) << 8)
                                      | ahc_inb(ahc, ULTRA_ENB);
        }

        if ((ahc->features & (AHC_WIDE|AHC_TWIN)) == 0)
                max_targ = 7;

        for (i = 0; i <= max_targ; i++) {
                struct ahc_initiator_tinfo *tinfo;
                struct ahc_tmode_tstate *tstate;
                u_int our_id;
                u_int target_id;
                char channel;

                channel = 'A';
                our_id = ahc->our_id;
                target_id = i;
                if (i > 7 && (ahc->features & AHC_TWIN) != 0) {
                        channel = 'B';
                        our_id = ahc->our_id_b;
                        target_id = i % 8;
                }
                tinfo = ahc_fetch_transinfo(ahc, channel, our_id,
                                            target_id, &tstate);
                /* Default to async narrow across the board */
                memset(tinfo, 0, sizeof(*tinfo));
                if (ahc->flags & AHC_USEDEFAULTS) {
                        if ((ahc->features & AHC_WIDE) != 0)
                                tinfo->user.width = MSG_EXT_WDTR_BUS_16_BIT;

                        /*
                         * These will be truncated when we determine the
                         * connection type we have with the target.
                         */
                        tinfo->user.period = ahc_syncrates->period;
                        tinfo->user.offset = MAX_OFFSET;
                } else {
                        u_int scsirate;
                        uint16_t mask;

                        /* Take the settings leftover in scratch RAM. */
                        scsirate = ahc_inb(ahc, TARG_SCSIRATE + i);
                        mask = (0x01 << i);
                        if ((ahc->features & AHC_ULTRA2) != 0) {
                                u_int offset;
                                u_int maxsync;

                                if ((scsirate & SOFS) == 0x0F) {
                                        /*
                                         * Haven't negotiated yet,
                                         * so the format is different.
                                         */
                                        scsirate = (scsirate & SXFR) >> 4
                                                 | (ultraenb & mask)
                                                  ? 0x08 : 0x0
                                                 | (scsirate & WIDEXFER);
                                        offset = MAX_OFFSET_ULTRA2;
                                } else
                                        offset = ahc_inb(ahc, TARG_OFFSET + i);
                                if ((scsirate & ~WIDEXFER) == 0 && offset != 0)
                                        /* Set to the lowest sync rate, 5MHz */
                                        scsirate |= 0x1c;
                                maxsync = AHC_SYNCRATE_ULTRA2;
                                if ((ahc->features & AHC_DT) != 0)
                                        maxsync = AHC_SYNCRATE_DT;
                                tinfo->user.period =
                                    ahc_find_period(ahc, scsirate, maxsync);
                                if (offset == 0)
                                        tinfo->user.period = 0;
                                else
                                        tinfo->user.offset = MAX_OFFSET;
                                if ((scsirate & SXFR_ULTRA2) <= 8/*10MHz*/
                                 && (ahc->features & AHC_DT) != 0)
                                        tinfo->user.ppr_options =
                                            MSG_EXT_PPR_DT_REQ;
                        } else if ((scsirate & SOFS) != 0) {
                                if ((scsirate & SXFR) == 0x40
                                 && (ultraenb & mask) != 0) {
                                        /* Treat 10MHz as a non-ultra speed */
                                        scsirate &= ~SXFR;
                                         ultraenb &= ~mask;
                                }
                                tinfo->user.period = 
                                    ahc_find_period(ahc, scsirate,
                                                    (ultraenb & mask)
                                                   ? AHC_SYNCRATE_ULTRA
                                                   : AHC_SYNCRATE_FAST);
                                if (tinfo->user.period != 0)
                                        tinfo->user.offset = MAX_OFFSET;
                        }
                        if (tinfo->user.period == 0)
                                tinfo->user.offset = 0;
                        if ((scsirate & WIDEXFER) != 0
                         && (ahc->features & AHC_WIDE) != 0)
                                tinfo->user.width = MSG_EXT_WDTR_BUS_16_BIT;
                        tinfo->user.protocol_version = 4;
                        if ((ahc->features & AHC_DT) != 0)
                                tinfo->user.transport_version = 3;
                        else
                                tinfo->user.transport_version = 2;
                        tinfo->goal.protocol_version = 2;
                        tinfo->goal.transport_version = 2;
                        tinfo->curr.protocol_version = 2;
                        tinfo->curr.transport_version = 2;
                }
                tstate->ultraenb = 0;
        }
        ahc->user_discenable = discenable;
        ahc->user_tagenable = tagenable;

        return (ahc->bus_chip_init(ahc));
}

void
ahc_intr_enable(struct ahc_softc *ahc, int enable)
{
        u_int hcntrl;

        hcntrl = ahc_inb(ahc, HCNTRL);
        hcntrl &= ~INTEN;
        ahc->pause &= ~INTEN;
        ahc->unpause &= ~INTEN;
        if (enable) {
                hcntrl |= INTEN;
                ahc->pause |= INTEN;
                ahc->unpause |= INTEN;
        }
        ahc_outb(ahc, HCNTRL, hcntrl);
}

/*
 * Ensure that the card is paused in a location
 * outside of all critical sections and that all
 * pending work is completed prior to returning.
 * This routine should only be called from outside
 * an interrupt context.
 */
void
ahc_pause_and_flushwork(struct ahc_softc *ahc)
{
        int intstat;
        int maxloops;
        int paused;

        maxloops = 1000;
        ahc->flags |= AHC_ALL_INTERRUPTS;
        paused = FALSE;
        do {
                if (paused) {
                        ahc_unpause(ahc);
                        /*
                         * Give the sequencer some time to service
                         * any active selections.
                         */
                        ahc_delay(500);
                }
                ahc_intr(ahc);
                ahc_pause(ahc);
                paused = TRUE;
                ahc_outb(ahc, SCSISEQ, ahc_inb(ahc, SCSISEQ) & ~ENSELO);
                intstat = ahc_inb(ahc, INTSTAT);
                if ((intstat & INT_PEND) == 0) {
                        ahc_clear_critical_section(ahc);
                        intstat = ahc_inb(ahc, INTSTAT);
                }
        } while (--maxloops
              && (intstat != 0xFF || (ahc->features & AHC_REMOVABLE) == 0)
              && ((intstat & INT_PEND) != 0
               || (ahc_inb(ahc, SSTAT0) & (SELDO|SELINGO)) != 0));
        if (maxloops == 0) {
                printf("Infinite interrupt loop, INTSTAT = %x",
                       ahc_inb(ahc, INTSTAT));
        }
        ahc_platform_flushwork(ahc);
        ahc->flags &= ~AHC_ALL_INTERRUPTS;
}

#ifdef CONFIG_PM
int
ahc_suspend(struct ahc_softc *ahc)
{

        ahc_pause_and_flushwork(ahc);

        if (LIST_FIRST(&ahc->pending_scbs) != NULL) {
                ahc_unpause(ahc);
                return (EBUSY);
        }

#ifdef AHC_TARGET_MODE
        /*
         * XXX What about ATIOs that have not yet been serviced?
         * Perhaps we should just refuse to be suspended if we
         * are acting in a target role.
         */
        if (ahc->pending_device != NULL) {
                ahc_unpause(ahc);
                return (EBUSY);
        }
#endif
        ahc_shutdown(ahc);
        return (0);
}

int
ahc_resume(struct ahc_softc *ahc)
{

        ahc_reset(ahc, /*reinit*/TRUE);
        ahc_intr_enable(ahc, TRUE); 
        ahc_restart(ahc);
        return (0);
}
#endif
/************************** Busy Target Table *********************************/
/*
 * Return the untagged transaction id for a given target/channel lun.
 * Optionally, clear the entry.
 */
static u_int
ahc_index_busy_tcl(struct ahc_softc *ahc, u_int tcl)
{
        u_int scbid;
        u_int target_offset;

        if ((ahc->flags & AHC_SCB_BTT) != 0) {
                u_int saved_scbptr;
                
                saved_scbptr = ahc_inb(ahc, SCBPTR);
                ahc_outb(ahc, SCBPTR, TCL_LUN(tcl));
                scbid = ahc_inb(ahc, SCB_64_BTT + TCL_TARGET_OFFSET(tcl));
                ahc_outb(ahc, SCBPTR, saved_scbptr);
        } else {
                target_offset = TCL_TARGET_OFFSET(tcl);
                scbid = ahc_inb(ahc, BUSY_TARGETS + target_offset);
        }

        return (scbid);
}

static void
ahc_unbusy_tcl(struct ahc_softc *ahc, u_int tcl)
{
        u_int target_offset;

        if ((ahc->flags & AHC_SCB_BTT) != 0) {
                u_int saved_scbptr;
                
                saved_scbptr = ahc_inb(ahc, SCBPTR);
                ahc_outb(ahc, SCBPTR, TCL_LUN(tcl));
                ahc_outb(ahc, SCB_64_BTT+TCL_TARGET_OFFSET(tcl), SCB_LIST_NULL);
                ahc_outb(ahc, SCBPTR, saved_scbptr);
        } else {
                target_offset = TCL_TARGET_OFFSET(tcl);
                ahc_outb(ahc, BUSY_TARGETS + target_offset, SCB_LIST_NULL);
        }
}

static void
ahc_busy_tcl(struct ahc_softc *ahc, u_int tcl, u_int scbid)
{
        u_int target_offset;

        if ((ahc->flags & AHC_SCB_BTT) != 0) {
                u_int saved_scbptr;
                
                saved_scbptr = ahc_inb(ahc, SCBPTR);
                ahc_outb(ahc, SCBPTR, TCL_LUN(tcl));
                ahc_outb(ahc, SCB_64_BTT + TCL_TARGET_OFFSET(tcl), scbid);
                ahc_outb(ahc, SCBPTR, saved_scbptr);
        } else {
                target_offset = TCL_TARGET_OFFSET(tcl);
                ahc_outb(ahc, BUSY_TARGETS + target_offset, scbid);
        }
}

/************************** SCB and SCB queue management **********************/
int
ahc_match_scb(struct ahc_softc *ahc, struct scb *scb, int target,
              char channel, int lun, u_int tag, role_t role)
{
        int targ = SCB_GET_TARGET(ahc, scb);
        char chan = SCB_GET_CHANNEL(ahc, scb);
        int slun = SCB_GET_LUN(scb);
        int match;

        match = ((chan == channel) || (channel == ALL_CHANNELS));
        if (match != 0)
                match = ((targ == target) || (target == CAM_TARGET_WILDCARD));
        if (match != 0)
                match = ((lun == slun) || (lun == CAM_LUN_WILDCARD));
        if (match != 0) {
#ifdef AHC_TARGET_MODE
                int group;

                group = XPT_FC_GROUP(scb->io_ctx->ccb_h.func_code);
                if (role == ROLE_INITIATOR) {
                        match = (group != XPT_FC_GROUP_TMODE)
                              && ((tag == scb->hscb->tag)
                               || (tag == SCB_LIST_NULL));
                } else if (role == ROLE_TARGET) {
                        match = (group == XPT_FC_GROUP_TMODE)
                              && ((tag == scb->io_ctx->csio.tag_id)
                               || (tag == SCB_LIST_NULL));
                }
#else /* !AHC_TARGET_MODE */
                match = ((tag == scb->hscb->tag) || (tag == SCB_LIST_NULL));
#endif /* AHC_TARGET_MODE */
        }

        return match;
}

static void
ahc_freeze_devq(struct ahc_softc *ahc, struct scb *scb)
{
        int        target;
        char        channel;
        int        lun;

        target = SCB_GET_TARGET(ahc, scb);
        lun = SCB_GET_LUN(scb);
        channel = SCB_GET_CHANNEL(ahc, scb);
        
        ahc_search_qinfifo(ahc, target, channel, lun,
                           /*tag*/SCB_LIST_NULL, ROLE_UNKNOWN,
                           CAM_REQUEUE_REQ, SEARCH_COMPLETE);

        ahc_platform_freeze_devq(ahc, scb);
}

void
ahc_qinfifo_requeue_tail(struct ahc_softc *ahc, struct scb *scb)
{
        struct scb *prev_scb;

        prev_scb = NULL;
        if (ahc_qinfifo_count(ahc) != 0) {
                u_int prev_tag;
                uint8_t prev_pos;

                prev_pos = ahc->qinfifonext - 1;
                prev_tag = ahc->qinfifo[prev_pos];
                prev_scb = ahc_lookup_scb(ahc, prev_tag);
        }
        ahc_qinfifo_requeue(ahc, prev_scb, scb);
        if ((ahc->features & AHC_QUEUE_REGS) != 0) {
                ahc_outb(ahc, HNSCB_QOFF, ahc->qinfifonext);
        } else {
                ahc_outb(ahc, KERNEL_QINPOS, ahc->qinfifonext);
        }
}

static void
ahc_qinfifo_requeue(struct ahc_softc *ahc, struct scb *prev_scb,
                    struct scb *scb)
{
        if (prev_scb == NULL) {
                ahc_outb(ahc, NEXT_QUEUED_SCB, scb->hscb->tag);
        } else {
                prev_scb->hscb->next = scb->hscb->tag;
                ahc_sync_scb(ahc, prev_scb, 
                             BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
        }
        ahc->qinfifo[ahc->qinfifonext++] = scb->hscb->tag;
        scb->hscb->next = ahc->next_queued_scb->hscb->tag;
        ahc_sync_scb(ahc, scb, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
}

static int
ahc_qinfifo_count(struct ahc_softc *ahc)
{
        uint8_t qinpos;
        uint8_t diff;

        if ((ahc->features & AHC_QUEUE_REGS) != 0) {
                qinpos = ahc_inb(ahc, SNSCB_QOFF);
                ahc_outb(ahc, SNSCB_QOFF, qinpos);
        } else
                qinpos = ahc_inb(ahc, QINPOS);
        diff = ahc->qinfifonext - qinpos;
        return (diff);
}

int
ahc_search_qinfifo(struct ahc_softc *ahc, int target, char channel,
                   int lun, u_int tag, role_t role, uint32_t status,
                   ahc_search_action action)
{
        struct        scb *scb;
        struct        scb *prev_scb;
        uint8_t qinstart;
        uint8_t qinpos;
        uint8_t qintail;
        uint8_t next;
        uint8_t prev;
        uint8_t curscbptr;
        int        found;
        int        have_qregs;

        qintail = ahc->qinfifonext;
        have_qregs = (ahc->features & AHC_QUEUE_REGS) != 0;
        if (have_qregs) {
                qinstart = ahc_inb(ahc, SNSCB_QOFF);
                ahc_outb(ahc, SNSCB_QOFF, qinstart);
        } else
                qinstart = ahc_inb(ahc, QINPOS);
        qinpos = qinstart;
        found = 0;
        prev_scb = NULL;

        if (action == SEARCH_COMPLETE) {
                /*
                 * Don't attempt to run any queued untagged transactions
                 * until we are done with the abort process.
                 */
                ahc_freeze_untagged_queues(ahc);
        }

        /*
         * Start with an empty queue.  Entries that are not chosen
         * for removal will be re-added to the queue as we go.
         */
        ahc->qinfifonext = qinpos;
        ahc_outb(ahc, NEXT_QUEUED_SCB, ahc->next_queued_scb->hscb->tag);

        while (qinpos != qintail) {
                scb = ahc_lookup_scb(ahc, ahc->qinfifo[qinpos]);
                if (scb == NULL) {
                        printf("qinpos = %d, SCB index = %d\n",
                                qinpos, ahc->qinfifo[qinpos]);
                        panic("Loop 1\n");
                }

                if (ahc_match_scb(ahc, scb, target, channel, lun, tag, role)) {
                        /*
                         * We found an scb that needs to be acted on.
                         */
                        found++;
                        switch (action) {
                        case SEARCH_COMPLETE:
                        {
                                cam_status ostat;
                                cam_status cstat;

                                ostat = ahc_get_transaction_status(scb);
                                if (ostat == CAM_REQ_INPROG)
                                        ahc_set_transaction_status(scb, status);
                                cstat = ahc_get_transaction_status(scb);
                                if (cstat != CAM_REQ_CMP)
                                        ahc_freeze_scb(scb);
                                if ((scb->flags & SCB_ACTIVE) == 0)
                                        printf("Inactive SCB in qinfifo\n");
                                ahc_done(ahc, scb);

                                /* FALLTHROUGH */
                        }
                        case SEARCH_REMOVE:
                                break;
                        case SEARCH_COUNT:
                                ahc_qinfifo_requeue(ahc, prev_scb, scb);
                                prev_scb = scb;
                                break;
                        }
                } else {
                        ahc_qinfifo_requeue(ahc, prev_scb, scb);
                        prev_scb = scb;
                }
                qinpos++;
        }

        if ((ahc->features & AHC_QUEUE_REGS) != 0) {
                ahc_outb(ahc, HNSCB_QOFF, ahc->qinfifonext);
        } else {
                ahc_outb(ahc, KERNEL_QINPOS, ahc->qinfifonext);
        }

        if (action != SEARCH_COUNT
         && (found != 0)
         && (qinstart != ahc->qinfifonext)) {
                /*
                 * The sequencer may be in the process of dmaing
                 * down the SCB at the beginning of the queue.
                 * This could be problematic if either the first,
                 * or the second SCB is removed from the queue
                 * (the first SCB includes a pointer to the "next"
                 * SCB to dma). If we have removed any entries, swap
                 * the first element in the queue with the next HSCB
                 * so the sequencer will notice that NEXT_QUEUED_SCB
                 * has changed during its dma attempt and will retry
                 * the DMA.
                 */
                scb = ahc_lookup_scb(ahc, ahc->qinfifo[qinstart]);

                if (scb == NULL) {
                        printf("found = %d, qinstart = %d, qinfifionext = %d\n",
                                found, qinstart, ahc->qinfifonext);
                        panic("First/Second Qinfifo fixup\n");
                }
                /*
                 * ahc_swap_with_next_hscb forces our next pointer to
                 * point to the reserved SCB for future commands.  Save
                 * and restore our original next pointer to maintain
                 * queue integrity.
                 */
                next = scb->hscb->next;
                ahc->scb_data->scbindex[scb->hscb->tag] = NULL;
                ahc_swap_with_next_hscb(ahc, scb);
                scb->hscb->next = next;
                ahc->qinfifo[qinstart] = scb->hscb->tag;

                /* Tell the card about the new head of the qinfifo. */
                ahc_outb(ahc, NEXT_QUEUED_SCB, scb->hscb->tag);

                /* Fixup the tail "next" pointer. */
                qintail = ahc->qinfifonext - 1;
                scb = ahc_lookup_scb(ahc, ahc->qinfifo[qintail]);
                scb->hscb->next = ahc->next_queued_scb->hscb->tag;
        }

        /*
         * Search waiting for selection list.
         */
        curscbptr = ahc_inb(ahc, SCBPTR);
        next = ahc_inb(ahc, WAITING_SCBH);  /* Start at head of list. */
        prev = SCB_LIST_NULL;

        while (next != SCB_LIST_NULL) {
                uint8_t scb_index;

                ahc_outb(ahc, SCBPTR, next);
                scb_index = ahc_inb(ahc, SCB_TAG);
                if (scb_index >= ahc->scb_data->numscbs) {
                        printf("Waiting List inconsistency. "
                               "SCB index == %d, yet numscbs == %d.",
                               scb_index, ahc->scb_data->numscbs);
                        ahc_dump_card_state(ahc);
                        panic("for safety");
                }
                scb = ahc_lookup_scb(ahc, scb_index);
                if (scb == NULL) {
                        printf("scb_index = %d, next = %d\n",
                                scb_index, next);
                        panic("Waiting List traversal\n");
                }
                if (ahc_match_scb(ahc, scb, target, channel,
                                  lun, SCB_LIST_NULL, role)) {
                        /*
                         * We found an scb that needs to be acted on.
                         */
                        found++;
                        switch (action) {
                        case SEARCH_COMPLETE:
                        {
                                cam_status ostat;
                                cam_status cstat;

                                ostat = ahc_get_transaction_status(scb);
                                if (ostat == CAM_REQ_INPROG)
                                        ahc_set_transaction_status(scb,
                                                                   status);
                                cstat = ahc_get_transaction_status(scb);
                                if (cstat != CAM_REQ_CMP)
                                        ahc_freeze_scb(scb);
                                if ((scb->flags & SCB_ACTIVE) == 0)
                                        printf("Inactive SCB in Waiting List\n");
                                ahc_done(ahc, scb);
                                /* FALLTHROUGH */
                        }
                        case SEARCH_REMOVE:
                                next = ahc_rem_wscb(ahc, next, prev);
                                break;
                        case SEARCH_COUNT:
                                prev = next;
                                next = ahc_inb(ahc, SCB_NEXT);
                                break;
                        }
                } else {
                        
                        prev = next;
                        next = ahc_inb(ahc, SCB_NEXT);
                }
        }
        ahc_outb(ahc, SCBPTR, curscbptr);

        found += ahc_search_untagged_queues(ahc, /*ahc_io_ctx_t*/NULL, target,
                                            channel, lun, status, action);

        if (action == SEARCH_COMPLETE)
                ahc_release_untagged_queues(ahc);
        return (found);
}

int
ahc_search_untagged_queues(struct ahc_softc *ahc, ahc_io_ctx_t ctx,
                           int target, char channel, int lun, uint32_t status,
                           ahc_search_action action)
{
        struct        scb *scb;
        int        maxtarget;
        int        found;
        int        i;

        if (action == SEARCH_COMPLETE) {
                /*
                 * Don't attempt to run any queued untagged transactions
                 * until we are done with the abort process.
                 */
                ahc_freeze_untagged_queues(ahc);
        }

        found = 0;
        i = 0;
        if ((ahc->flags & AHC_SCB_BTT) == 0) {

                maxtarget = 16;
                if (target != CAM_TARGET_WILDCARD) {

                        i = target;
                        if (channel == 'B')
                                i += 8;
                        maxtarget = i + 1;
                }
        } else {
                maxtarget = 0;
        }

        for (; i < maxtarget; i++) {
                struct scb_tailq *untagged_q;
                struct scb *next_scb;

                untagged_q = &(ahc->untagged_queues[i]);
                next_scb = TAILQ_FIRST(untagged_q);
                while (next_scb != NULL) {

                        scb = next_scb;
                        next_scb = TAILQ_NEXT(scb, links.tqe);

                        /*
                         * The head of the list may be the currently
                         * active untagged command for a device.
                         * We're only searching for commands that
                         * have not been started.  A transaction
                         * marked active but still in the qinfifo
                         * is removed by the qinfifo scanning code
                         * above.
                         */
                        if ((scb->flags & SCB_ACTIVE) != 0)
                                continue;

                        if (ahc_match_scb(ahc, scb, target, channel, lun,
                                          SCB_LIST_NULL, ROLE_INITIATOR) == 0
                         || (ctx != NULL && ctx != scb->io_ctx))
                                continue;

                        /*
                         * We found an scb that needs to be acted on.
                         */
                        found++;
                        switch (action) {
                        case SEARCH_COMPLETE:
                        {
                                cam_status ostat;
                                cam_status cstat;

                                ostat = ahc_get_transaction_status(scb);
                                if (ostat == CAM_REQ_INPROG)
                                        ahc_set_transaction_status(scb, status);
                                cstat = ahc_get_transaction_status(scb);
                                if (cstat != CAM_REQ_CMP)
                                        ahc_freeze_scb(scb);
                                if ((scb->flags & SCB_ACTIVE) == 0)
                                        printf("Inactive SCB in untaggedQ\n");
                                ahc_done(ahc, scb);
                                break;
                        }
                        case SEARCH_REMOVE:
                                scb->flags &= ~SCB_UNTAGGEDQ;
                                TAILQ_REMOVE(untagged_q, scb, links.tqe);
                                break;
                        case SEARCH_COUNT:
                                break;
                        }
                }
        }

        if (action == SEARCH_COMPLETE)
                ahc_release_untagged_queues(ahc);
        return (found);
}

int
ahc_search_disc_list(struct ahc_softc *ahc, int target, char channel,
                     int lun, u_int tag, int stop_on_first, int remove,
                     int save_state)
{
        struct        scb *scbp;
        u_int        next;
        u_int        prev;
        u_int        count;
        u_int        active_scb;

        count = 0;
        next = ahc_inb(ahc, DISCONNECTED_SCBH);
        prev = SCB_LIST_NULL;

        if (save_state) {
                /* restore this when we're done */
                active_scb = ahc_inb(ahc, SCBPTR);
        } else
                /* Silence compiler */
                active_scb = SCB_LIST_NULL;

        while (next != SCB_LIST_NULL) {
                u_int scb_index;

                ahc_outb(ahc, SCBPTR, next);
                scb_index = ahc_inb(ahc, SCB_TAG);
                if (scb_index >= ahc->scb_data->numscbs) {
                        printf("Disconnected List inconsistency. "
                               "SCB index == %d, yet numscbs == %d.",
                               scb_index, ahc->scb_data->numscbs);
                        ahc_dump_card_state(ahc);
                        panic("for safety");
                }

                if (next == prev) {
                        panic("Disconnected List Loop. "
                              "cur SCBPTR == %x, prev SCBPTR == %x.",
                              next, prev);
                }
                scbp = ahc_lookup_scb(ahc, scb_index);
                if (ahc_match_scb(ahc, scbp, target, channel, lun,
                                  tag, ROLE_INITIATOR)) {
                        count++;
                        if (remove) {
                                next =
                                    ahc_rem_scb_from_disc_list(ahc, prev, next);
                        } else {
                                prev = next;
                                next = ahc_inb(ahc, SCB_NEXT);
                        }
                        if (stop_on_first)
                                break;
                } else {
                        prev = next;
                        next = ahc_inb(ahc, SCB_NEXT);
                }
        }
        if (save_state)
                ahc_outb(ahc, SCBPTR, active_scb);
        return (count);
}

/*
 * Remove an SCB from the on chip list of disconnected transactions.
 * This is empty/unused if we are not performing SCB paging.
 */
static u_int
ahc_rem_scb_from_disc_list(struct ahc_softc *ahc, u_int prev, u_int scbptr)
{
        u_int next;

        ahc_outb(ahc, SCBPTR, scbptr);
        next = ahc_inb(ahc, SCB_NEXT);

        ahc_outb(ahc, SCB_CONTROL, 0);

        ahc_add_curscb_to_free_list(ahc);

        if (prev != SCB_LIST_NULL) {
                ahc_outb(ahc, SCBPTR, prev);
                ahc_outb(ahc, SCB_NEXT, next);
        } else
                ahc_outb(ahc, DISCONNECTED_SCBH, next);

        return (next);
}

/*
 * Add the SCB as selected by SCBPTR onto the on chip list of
 * free hardware SCBs.  This list is empty/unused if we are not
 * performing SCB paging.
 */
static void
ahc_add_curscb_to_free_list(struct ahc_softc *ahc)
{
        /*
         * Invalidate the tag so that our abort
         * routines don't think it's active.
         */
        ahc_outb(ahc, SCB_TAG, SCB_LIST_NULL);

        if ((ahc->flags & AHC_PAGESCBS) != 0) {
                ahc_outb(ahc, SCB_NEXT, ahc_inb(ahc, FREE_SCBH));
                ahc_outb(ahc, FREE_SCBH, ahc_inb(ahc, SCBPTR));
        }
}

/*
 * Manipulate the waiting for selection list and return the
 * scb that follows the one that we remove.
 */
static u_int
ahc_rem_wscb(struct ahc_softc *ahc, u_int scbpos, u_int prev)
{
        u_int curscb, next;

        /*
         * Select the SCB we want to abort and
         * pull the next pointer out of it.
         */
        curscb = ahc_inb(ahc, SCBPTR);
        ahc_outb(ahc, SCBPTR, scbpos);
        next = ahc_inb(ahc, SCB_NEXT);

        /* Clear the necessary fields */
        ahc_outb(ahc, SCB_CONTROL, 0);

        ahc_add_curscb_to_free_list(ahc);

        /* update the waiting list */
        if (prev == SCB_LIST_NULL) {
                /* First in the list */
                ahc_outb(ahc, WAITING_SCBH, next); 

                /*
                 * Ensure we aren't attempting to perform
                 * selection for this entry.
                 */
                ahc_outb(ahc, SCSISEQ, (ahc_inb(ahc, SCSISEQ) & ~ENSELO));
        } else {
                /*
                 * Select the scb that pointed to us 
                 * and update its next pointer.
                 */
                ahc_outb(ahc, SCBPTR, prev);
                ahc_outb(ahc, SCB_NEXT, next);
        }

        /*
         * Point us back at the original scb position.
         */
        ahc_outb(ahc, SCBPTR, curscb);
        return next;
}

/******************************** Error Handling ******************************/
/*
 * Abort all SCBs that match the given description (target/channel/lun/tag),
 * setting their status to the passed in status if the status has not already
 * been modified from CAM_REQ_INPROG.  This routine assumes that the sequencer
 * is paused before it is called.
 */
static int
ahc_abort_scbs(struct ahc_softc *ahc, int target, char channel,
               int lun, u_int tag, role_t role, uint32_t status)
{
        struct        scb *scbp;
        struct        scb *scbp_next;
        u_int        active_scb;
        int        i, j;
        int        maxtarget;
        int        minlun;
        int        maxlun;

        int        found;

        /*
         * Don't attempt to run any queued untagged transactions
         * until we are done with the abort process.
         */
        ahc_freeze_untagged_queues(ahc);

        /* restore this when we're done */
        active_scb = ahc_inb(ahc, SCBPTR);

        found = ahc_search_qinfifo(ahc, target, channel, lun, SCB_LIST_NULL,
                                   role, CAM_REQUEUE_REQ, SEARCH_COMPLETE);

        /*
         * Clean out the busy target table for any untagged commands.
         */
        i = 0;
        maxtarget = 16;
        if (target != CAM_TARGET_WILDCARD) {
                i = target;
                if (channel == 'B')
                        i += 8;
                maxtarget = i + 1;
        }

        if (lun == CAM_LUN_WILDCARD) {

                /*
                 * Unless we are using an SCB based
                 * busy targets table, there is only
                 * one table entry for all luns of
                 * a target.
                 */
                minlun = 0;
                maxlun = 1;
                if ((ahc->flags & AHC_SCB_BTT) != 0)
                        maxlun = AHC_NUM_LUNS;
        } else {
                minlun = lun;
                maxlun = lun + 1;
        }

        if (role != ROLE_TARGET) {
                for (;i < maxtarget; i++) {
                        for (j = minlun;j < maxlun; j++) {
                                u_int scbid;
                                u_int tcl;

                                tcl = BUILD_TCL(i << 4, j);
                                scbid = ahc_index_busy_tcl(ahc, tcl);
                                scbp = ahc_lookup_scb(ahc, scbid);
                                if (scbp == NULL
                                 || ahc_match_scb(ahc, scbp, target, channel,
                                                  lun, tag, role) == 0)
                                        continue;
                                ahc_unbusy_tcl(ahc, BUILD_TCL(i << 4, j));
                        }
                }

                /*
                 * Go through the disconnected list and remove any entries we
                 * have queued for completion, 0'ing their control byte too.
                 * We save the active SCB and restore it ourselves, so there
                 * is no reason for this search to restore it too.
                 */
                ahc_search_disc_list(ahc, target, channel, lun, tag,
                                     /*stop_on_first*/FALSE, /*remove*/TRUE,
                                     /*save_state*/FALSE);
        }

        /*
         * Go through the hardware SCB array looking for commands that
         * were active but not on any list.  In some cases, these remnants
         * might not still have mappings in the scbindex array (e.g. unexpected
         * bus free with the same scb queued for an abort).  Don't hold this
         * against them.
         */
        for (i = 0; i < ahc->scb_data->maxhscbs; i++) {
                u_int scbid;

                ahc_outb(ahc, SCBPTR, i);
                scbid = ahc_inb(ahc, SCB_TAG);
                scbp = ahc_lookup_scb(ahc, scbid);
                if ((scbp == NULL && scbid != SCB_LIST_NULL)
                 || (scbp != NULL
                  && ahc_match_scb(ahc, scbp, target, channel, lun, tag, role)))
                        ahc_add_curscb_to_free_list(ahc);
        }

        /*
         * Go through the pending CCB list and look for
         * commands for this target that are still active.
         * These are other tagged commands that were
         * disconnected when the reset occurred.
         */
        scbp_next = LIST_FIRST(&ahc->pending_scbs);
        while (scbp_next != NULL) {
                scbp = scbp_next;
                scbp_next = LIST_NEXT(scbp, pending_links);
                if (ahc_match_scb(ahc, scbp, target, channel, lun, tag, role)) {
                        cam_status ostat;

                        ostat = ahc_get_transaction_status(scbp);
                        if (ostat == CAM_REQ_INPROG)
                                ahc_set_transaction_status(scbp, status);
                        if (ahc_get_transaction_status(scbp) != CAM_REQ_CMP)
                                ahc_freeze_scb(scbp);
                        if ((scbp->flags & SCB_ACTIVE) == 0)
                                printf("Inactive SCB on pending list\n");
                        ahc_done(ahc, scbp);
                        found++;
                }
        }
        ahc_outb(ahc, SCBPTR, active_scb);
        ahc_platform_abort_scbs(ahc, target, channel, lun, tag, role, status);
        ahc_release_untagged_queues(ahc);
        return found;
}

static void
ahc_reset_current_bus(struct ahc_softc *ahc)
{
        uint8_t scsiseq;

        ahc_outb(ahc, SIMODE1, ahc_inb(ahc, SIMODE1) & ~ENSCSIRST);
        scsiseq = ahc_inb(ahc, SCSISEQ);
        ahc_outb(ahc, SCSISEQ, scsiseq | SCSIRSTO);
        ahc_flush_device_writes(ahc);
        ahc_delay(AHC_BUSRESET_DELAY);
        /* Turn off the bus reset */
        ahc_outb(ahc, SCSISEQ, scsiseq & ~SCSIRSTO);

        ahc_clear_intstat(ahc);

        /* Re-enable reset interrupts */
        ahc_outb(ahc, SIMODE1, ahc_inb(ahc, SIMODE1) | ENSCSIRST);
}

int
ahc_reset_channel(struct ahc_softc *ahc, char channel, int initiate_reset)
{
        struct        ahc_devinfo devinfo;
        u_int        initiator, target, max_scsiid;
        u_int        sblkctl;
        u_int        scsiseq;
        u_int        simode1;
        int        found;
        int        restart_needed;
        char        cur_channel;

        ahc->pending_device = NULL;

        ahc_compile_devinfo(&devinfo,
                            CAM_TARGET_WILDCARD,
                            CAM_TARGET_WILDCARD,
                            CAM_LUN_WILDCARD,
                            channel, ROLE_UNKNOWN);
        ahc_pause(ahc);

        /* Make sure the sequencer is in a safe location. */
        ahc_clear_critical_section(ahc);

        /*
         * Run our command complete fifos to ensure that we perform
         * completion processing on any commands that 'completed'
         * before the reset occurred.
         */
        ahc_run_qoutfifo(ahc);
#ifdef AHC_TARGET_MODE
        /*
         * XXX - In Twin mode, the tqinfifo may have commands
         *         for an unaffected channel in it.  However, if
         *         we have run out of ATIO resources to drain that
         *         queue, we may not get them all out here.  Further,
         *         the blocked transactions for the reset channel
         *         should just be killed off, irrespecitve of whether
         *         we are blocked on ATIO resources.  Write a routine
         *         to compact the tqinfifo appropriately.
         */
        if ((ahc->flags & AHC_TARGETROLE) != 0) {
                ahc_run_tqinfifo(ahc, /*paused*/TRUE);
        }
#endif

        /*
         * Reset the bus if we are initiating this reset
         */
        sblkctl = ahc_inb(ahc, SBLKCTL);
        cur_channel = 'A';
        if ((ahc->features & AHC_TWIN) != 0
         && ((sblkctl & SELBUSB) != 0))
            cur_channel = 'B';
        scsiseq = ahc_inb(ahc, SCSISEQ_TEMPLATE);
        if (cur_channel != channel) {
                /* Case 1: Command for another bus is active
                 * Stealthily reset the other bus without
                 * upsetting the current bus.
                 */
                ahc_outb(ahc, SBLKCTL, sblkctl ^ SELBUSB);
                simode1 = ahc_inb(ahc, SIMODE1) & ~(ENBUSFREE|ENSCSIRST);
#ifdef AHC_TARGET_MODE
                /*
                 * Bus resets clear ENSELI, so we cannot
                 * defer re-enabling bus reset interrupts
                 * if we are in target mode.
                 */
                if ((ahc->flags & AHC_TARGETROLE) != 0)
                        simode1 |= ENSCSIRST;
#endif
                ahc_outb(ahc, SIMODE1, simode1);
                if (initiate_reset)
                        ahc_reset_current_bus(ahc);
                ahc_clear_intstat(ahc);
                ahc_outb(ahc, SCSISEQ, scsiseq & (ENSELI|ENRSELI|ENAUTOATNP));
                ahc_outb(ahc, SBLKCTL, sblkctl);
                restart_needed = FALSE;
        } else {
                /* Case 2: A command from this bus is active or we're idle */
                simode1 = ahc_inb(ahc, SIMODE1) & ~(ENBUSFREE|ENSCSIRST);
#ifdef AHC_TARGET_MODE
                /*
                 * Bus resets clear ENSELI, so we cannot
                 * defer re-enabling bus reset interrupts
                 * if we are in target mode.
                 */
                if ((ahc->flags & AHC_TARGETROLE) != 0)
                        simode1 |= ENSCSIRST;
#endif
                ahc_outb(ahc, SIMODE1, simode1);
                if (initiate_reset)
                        ahc_reset_current_bus(ahc);
                ahc_clear_intstat(ahc);
                ahc_outb(ahc, SCSISEQ, scsiseq & (ENSELI|ENRSELI|ENAUTOATNP));
                restart_needed = TRUE;
        }

        /*
         * Clean up all the state information for the
         * pending transactions on this bus.
         */
        found = ahc_abort_scbs(ahc, CAM_TARGET_WILDCARD, channel,
                               CAM_LUN_WILDCARD, SCB_LIST_NULL,
                               ROLE_UNKNOWN, CAM_SCSI_BUS_RESET);

        max_scsiid = (ahc->features & AHC_WIDE) ? 15 : 7;

#ifdef AHC_TARGET_MODE
        /*
         * Send an immediate notify ccb to all target more peripheral
         * drivers affected by this action.
         */
        for (target = 0; target <= max_scsiid; target++) {
                struct ahc_tmode_tstate* tstate;
                u_int lun;

                tstate = ahc->enabled_targets[target];
                if (tstate == NULL)
                        continue;
                for (lun = 0; lun < AHC_NUM_LUNS; lun++) {
                        struct ahc_tmode_lstate* lstate;

                        lstate = tstate->enabled_luns[lun];
                        if (lstate == NULL)
                                continue;

                        ahc_queue_lstate_event(ahc, lstate, CAM_TARGET_WILDCARD,
                                               EVENT_TYPE_BUS_RESET, /*arg*/0);
                        ahc_send_lstate_events(ahc, lstate);
                }
        }
#endif
        /* Notify the XPT that a bus reset occurred */
        ahc_send_async(ahc, devinfo.channel, CAM_TARGET_WILDCARD,
                       CAM_LUN_WILDCARD, AC_BUS_RESET);

        /*
         * Revert to async/narrow transfers until we renegotiate.
         */
        for (target = 0; target <= max_scsiid; target++) {

                if (ahc->enabled_targets[target] == NULL)
                        continue;
                for (initiator = 0; initiator <= max_scsiid; initiator++) {
                        struct ahc_devinfo devinfo;

                        ahc_compile_devinfo(&devinfo, target, initiator,
                                            CAM_LUN_WILDCARD,
                                            channel, ROLE_UNKNOWN);
                        ahc_set_width(ahc, &devinfo, MSG_EXT_WDTR_BUS_8_BIT,
                                      AHC_TRANS_CUR, /*paused*/TRUE);
                        ahc_set_syncrate(ahc, &devinfo, /*syncrate*/NULL,
                                         /*period*/0, /*offset*/0,
                                         /*ppr_options*/0, AHC_TRANS_CUR,
                                         /*paused*/TRUE);
                }
        }

        if (restart_needed)
                ahc_restart(ahc);
        else
                ahc_unpause(ahc);
        return found;
}


/***************************** Residual Processing ****************************/
/*
 * Calculate the residual for a just completed SCB.
 */
static void
ahc_calc_residual(struct ahc_softc *ahc, struct scb *scb)
{
        struct hardware_scb *hscb;
        struct status_pkt *spkt;
        uint32_t sgptr;
        uint32_t resid_sgptr;
        uint32_t resid;

        /*
         * 5 cases.
         * 1) No residual.
         *    SG_RESID_VALID clear in sgptr.
         * 2) Transferless command
         * 3) Never performed any transfers.
         *    sgptr has SG_FULL_RESID set.
         * 4) No residual but target did not
         *    save data pointers after the
         *    last transfer, so sgptr was
         *    never updated.
         * 5) We have a partial residual.
         *    Use residual_sgptr to determine
         *    where we are.
         */

        hscb = scb->hscb;
        sgptr = ahc_le32toh(hscb->sgptr);
        if ((sgptr & SG_RESID_VALID) == 0)
                /* Case 1 */
                return;
        sgptr &= ~SG_RESID_VALID;

        if ((sgptr & SG_LIST_NULL) != 0)
                /* Case 2 */
                return;

        spkt = &hscb->shared_data.status;
        resid_sgptr = ahc_le32toh(spkt->residual_sg_ptr);
        if ((sgptr & SG_FULL_RESID) != 0) {
                /* Case 3 */
                resid = ahc_get_transfer_length(scb);
        } else if ((resid_sgptr & SG_LIST_NULL) != 0) {
                /* Case 4 */
                return;
        } else if ((resid_sgptr & ~SG_PTR_MASK) != 0) {
                panic("Bogus resid sgptr value 0x%x\n", resid_sgptr);
        } else {
                struct ahc_dma_seg *sg;

                /*
                 * Remainder of the SG where the transfer
                 * stopped.  
                 */
                resid = ahc_le32toh(spkt->residual_datacnt) & AHC_SG_LEN_MASK;
                sg = ahc_sg_bus_to_virt(scb, resid_sgptr & SG_PTR_MASK);

                /* The residual sg_ptr always points to the next sg */
                sg--;

                /*
                 * Add up the contents of all residual
                 * SG segments that are after the SG where
                 * the transfer stopped.
                 */
                while ((ahc_le32toh(sg->len) & AHC_DMA_LAST_SEG) == 0) {
                        sg++;
                        resid += ahc_le32toh(sg->len) & AHC_SG_LEN_MASK;
                }
        }
        if ((scb->flags & SCB_SENSE) == 0)
                ahc_set_residual(scb, resid);
        else
                ahc_set_sense_residual(scb, resid);

#ifdef AHC_DEBUG
        if ((ahc_debug & AHC_SHOW_MISC) != 0) {
                ahc_print_path(ahc, scb);
                printf("Handled %sResidual of %d bytes\n",
                       (scb->flags & SCB_SENSE) ? "Sense " : "", resid);
        }
#endif
}

/******************************* Target Mode **********************************/
#ifdef AHC_TARGET_MODE
/*
 * Add a target mode event to this lun's queue
 */
static void
ahc_queue_lstate_event(struct ahc_softc *ahc, struct ahc_tmode_lstate *lstate,
                       u_int initiator_id, u_int event_type, u_int event_arg)
{
        struct ahc_tmode_event *event;
        int pending;

        xpt_freeze_devq(lstate->path, /*count*/1);
        if (lstate->event_w_idx >= lstate->event_r_idx)
                pending = lstate->event_w_idx - lstate->event_r_idx;
        else
                pending = AHC_TMODE_EVENT_BUFFER_SIZE + 1
                        - (lstate->event_r_idx - lstate->event_w_idx);

        if (event_type == EVENT_TYPE_BUS_RESET
         || event_type == MSG_BUS_DEV_RESET) {
                /*
                 * Any earlier events are irrelevant, so reset our buffer.
                 * This has the effect of allowing us to deal with reset
                 * floods (an external device holding down the reset line)
                 * without losing the event that is really interesting.
                 */
                lstate->event_r_idx = 0;
                lstate->event_w_idx = 0;
                xpt_release_devq(lstate->path, pending, /*runqueue*/FALSE);
        }

        if (pending == AHC_TMODE_EVENT_BUFFER_SIZE) {
                xpt_print_path(lstate->path);
                printf("immediate event %x:%x lost\n",
                       lstate->event_buffer[lstate->event_r_idx].event_type,
                       lstate->event_buffer[lstate->event_r_idx].event_arg);
                lstate->event_r_idx++;
                if (lstate->event_r_idx == AHC_TMODE_EVENT_BUFFER_SIZE)
                        lstate->event_r_idx = 0;
                xpt_release_devq(lstate->path, /*count*/1, /*runqueue*/FALSE);
        }

        event = &lstate->event_buffer[lstate->event_w_idx];
        event->initiator_id = initiator_id;
        event->event_type = event_type;
        event->event_arg = event_arg;
        lstate->event_w_idx++;
        if (lstate->event_w_idx == AHC_TMODE_EVENT_BUFFER_SIZE)
                lstate->event_w_idx = 0;
}

/*
 * Send any target mode events queued up waiting
 * for immediate notify resources.
 */
void
ahc_send_lstate_events(struct ahc_softc *ahc, struct ahc_tmode_lstate *lstate)
{
        struct ccb_hdr *ccbh;
        struct ccb_immed_notify *inot;

        while (lstate->event_r_idx != lstate->event_w_idx
            && (ccbh = SLIST_FIRST(&lstate->immed_notifies)) != NULL) {
                struct ahc_tmode_event *event;

                event = &lstate->event_buffer[lstate->event_r_idx];
                SLIST_REMOVE_HEAD(&lstate->immed_notifies, sim_links.sle);
                inot = (struct ccb_immed_notify *)ccbh;
                switch (event->event_type) {
                case EVENT_TYPE_BUS_RESET:
                        ccbh->status = CAM_SCSI_BUS_RESET|CAM_DEV_QFRZN;
                        break;
                default:
                        ccbh->status = CAM_MESSAGE_RECV|CAM_DEV_QFRZN;
                        inot->message_args[0] = event->event_type;
                        inot->message_args[1] = event->event_arg;
                        break;
                }
                inot->initiator_id = event->initiator_id;
                inot->sense_len = 0;
                xpt_done((union ccb *)inot);
                lstate->event_r_idx++;
                if (lstate->event_r_idx == AHC_TMODE_EVENT_BUFFER_SIZE)
                        lstate->event_r_idx = 0;
        }
}
#endif

/******************** Sequencer Program Patching/Download *********************/

#ifdef AHC_DUMP_SEQ
void
ahc_dumpseq(struct ahc_softc* ahc)
{
        int i;

        ahc_outb(ahc, SEQCTL, PERRORDIS|FAILDIS|FASTMODE|LOADRAM);
        ahc_outb(ahc, SEQADDR0, 0);
        ahc_outb(ahc, SEQADDR1, 0);
        for (i = 0; i < ahc->instruction_ram_size; i++) {
                uint8_t ins_bytes[4];

                ahc_insb(ahc, SEQRAM, ins_bytes, 4);
                printf("0x%08x\n", ins_bytes[0] << 24
                                 | ins_bytes[1] << 16
                                 | ins_bytes[2] << 8
                                 | ins_bytes[3]);
        }
}
#endif

static int
ahc_loadseq(struct ahc_softc *ahc)
{
        struct        cs cs_table[num_critical_sections];
        u_int        begin_set[num_critical_sections];
        u_int        end_set[num_critical_sections];
        const struct patch *cur_patch;
        u_int        cs_count;
        u_int        cur_cs;
        u_int        i;
        u_int        skip_addr;
        u_int        sg_prefetch_cnt;
        int        downloaded;
        uint8_t        download_consts[7];

        /*
         * Start out with 0 critical sections
         * that apply to this firmware load.
         */
        cs_count = 0;
        cur_cs = 0;
        memset(begin_set, 0, sizeof(begin_set));
        memset(end_set, 0, sizeof(end_set));

        /* Setup downloadable constant table */
        download_consts[QOUTFIFO_OFFSET] = 0;
        if (ahc->targetcmds != NULL)
                download_consts[QOUTFIFO_OFFSET] += 32;
        download_consts[QINFIFO_OFFSET] = download_consts[QOUTFIFO_OFFSET] + 1;
        download_consts[CACHESIZE_MASK] = ahc->pci_cachesize - 1;
        download_consts[INVERTED_CACHESIZE_MASK] = ~(ahc->pci_cachesize - 1);
        sg_prefetch_cnt = ahc->pci_cachesize;
        if (sg_prefetch_cnt < (2 * sizeof(struct ahc_dma_seg)))
                sg_prefetch_cnt = 2 * sizeof(struct ahc_dma_seg);
        download_consts[SG_PREFETCH_CNT] = sg_prefetch_cnt;
        download_consts[SG_PREFETCH_ALIGN_MASK] = ~(sg_prefetch_cnt - 1);
        download_consts[SG_PREFETCH_ADDR_MASK] = (sg_prefetch_cnt - 1);

        cur_patch = patches;
        downloaded = 0;
        skip_addr = 0;
        ahc_outb(ahc, SEQCTL, PERRORDIS|FAILDIS|FASTMODE|LOADRAM);
        ahc_outb(ahc, SEQADDR0, 0);
        ahc_outb(ahc, SEQADDR1, 0);

        for (i = 0; i < sizeof(seqprog)/4; i++) {
                if (ahc_check_patch(ahc, &cur_patch, i, &skip_addr) == 0) {
                        /*
                         * Don't download this instruction as it
                         * is in a patch that was removed.
                         */
                        continue;
                }

                if (downloaded == ahc->instruction_ram_size) {
                        /*
                         * We're about to exceed the instruction
                         * storage capacity for this chip.  Fail
                         * the load.
                         */
                        printf("\n%s: Program too large for instruction memory "
                               "size of %d!\n", ahc_name(ahc),
                               ahc->instruction_ram_size);
                        return (ENOMEM);
                }

                /*
                 * Move through the CS table until we find a CS
                 * that might apply to this instruction.
                 */
                for (; cur_cs < num_critical_sections; cur_cs++) {
                        if (critical_sections[cur_cs].end <= i) {
                                if (begin_set[cs_count] == TRUE
                                 && end_set[cs_count] == FALSE) {
                                        cs_table[cs_count].end = downloaded;
                                         end_set[cs_count] = TRUE;
                                        cs_count++;
                                }
                                continue;
                        }
                        if (critical_sections[cur_cs].begin <= i
                         && begin_set[cs_count] == FALSE) {
                                cs_table[cs_count].begin = downloaded;
                                begin_set[cs_count] = TRUE;
                        }
                        break;
                }
                ahc_download_instr(ahc, i, download_consts);
                downloaded++;
        }

        ahc->num_critical_sections = cs_count;
        if (cs_count != 0) {

                cs_count *= sizeof(struct cs);
                ahc->critical_sections = malloc(cs_count, M_DEVBUF, M_NOWAIT);
                if (ahc->critical_sections == NULL)
                        panic("ahc_loadseq: Could not malloc");
                memcpy(ahc->critical_sections, cs_table, cs_count);
        }
        ahc_outb(ahc, SEQCTL, PERRORDIS|FAILDIS|FASTMODE);

        if (bootverbose) {
                printf(" %d instructions downloaded\n", downloaded);
                printf("%s: Features 0x%x, Bugs 0x%x, Flags 0x%x\n",
                       ahc_name(ahc), ahc->features, ahc->bugs, ahc->flags);
        }
        return (0);
}

static int
ahc_check_patch(struct ahc_softc *ahc, const struct patch **start_patch,
                u_int start_instr, u_int *skip_addr)
{
        const struct patch *cur_patch;
        const struct patch *last_patch;
        u_int        num_patches;

        num_patches = ARRAY_SIZE(patches);
        last_patch = &patches[num_patches];
        cur_patch = *start_patch;

        while (cur_patch < last_patch && start_instr == cur_patch->begin) {

                if (cur_patch->patch_func(ahc) == 0) {

                        /* Start rejecting code */
                        *skip_addr = start_instr + cur_patch->skip_instr;
                        cur_patch += cur_patch->skip_patch;
                } else {
                        /* Accepted this patch.  Advance to the next
                         * one and wait for our intruction pointer to
                         * hit this point.
                         */
                        cur_patch++;
                }
        }

        *start_patch = cur_patch;
        if (start_instr < *skip_addr)
                /* Still skipping */
                return (0);

        return (1);
}

static void
ahc_download_instr(struct ahc_softc *ahc, u_int instrptr, uint8_t *dconsts)
{
        union        ins_formats instr;
        struct        ins_format1 *fmt1_ins;
        struct        ins_format3 *fmt3_ins;
        u_int        opcode;

        /*
         * The firmware is always compiled into a little endian format.
         */
        instr.integer = ahc_le32toh(*(uint32_t*)&seqprog[instrptr * 4]);

        fmt1_ins = &instr.format1;
        fmt3_ins = NULL;

        /* Pull the opcode */
        opcode = instr.format1.opcode;
        switch (opcode) {
        case AIC_OP_JMP:
        case AIC_OP_JC:
        case AIC_OP_JNC:
        case AIC_OP_CALL:
        case AIC_OP_JNE:
        case AIC_OP_JNZ:
        case AIC_OP_JE:
        case AIC_OP_JZ:
        {
                const struct patch *cur_patch;
                int address_offset;
                u_int address;
                u_int skip_addr;
                u_int i;

                fmt3_ins = &instr.format3;
                address_offset = 0;
                address = fmt3_ins->address;
                cur_patch = patches;
                skip_addr = 0;

                for (i = 0; i < address;) {

                        ahc_check_patch(ahc, &cur_patch, i, &skip_addr);

                        if (skip_addr > i) {
                                int end_addr;

                                end_addr = min(address, skip_addr);
                                address_offset += end_addr - i;
                                i = skip_addr;
                        } else {
                                i++;
                        }
                }
                address -= address_offset;
                fmt3_ins->address = address;
                /* FALLTHROUGH */
        }
        case AIC_OP_OR:
        case AIC_OP_AND:
        case AIC_OP_XOR:
        case AIC_OP_ADD:
        case AIC_OP_ADC:
        case AIC_OP_BMOV:
                if (fmt1_ins->parity != 0) {
                        fmt1_ins->immediate = dconsts[fmt1_ins->immediate];
                }
                fmt1_ins->parity = 0;
                if ((ahc->features & AHC_CMD_CHAN) == 0
                 && opcode == AIC_OP_BMOV) {
                        /*
                         * Block move was added at the same time
                         * as the command channel.  Verify that
                         * this is only a move of a single element
                         * and convert the BMOV to a MOV
                         * (AND with an immediate of FF).
                         */
                        if (fmt1_ins->immediate != 1)
                                panic("%s: BMOV not supported\n",
                                      ahc_name(ahc));
                        fmt1_ins->opcode = AIC_OP_AND;
                        fmt1_ins->immediate = 0xff;
                }
                /* FALLTHROUGH */
        case AIC_OP_ROL:
                if ((ahc->features & AHC_ULTRA2) != 0) {
                        int i, count;

                        /* Calculate odd parity for the instruction */
                        for (i = 0, count = 0; i < 31; i++) {
                                uint32_t mask;

                                mask = 0x01 << i;
                                if ((instr.integer & mask) != 0)
                                        count++;
                        }
                        if ((count & 0x01) == 0)
                                instr.format1.parity = 1;
                } else {
                        /* Compress the instruction for older sequencers */
                        if (fmt3_ins != NULL) {
                                instr.integer =
                                        fmt3_ins->immediate
                                      | (fmt3_ins->source << 8)
                                      | (fmt3_ins->address << 16)
                                      |        (fmt3_ins->opcode << 25);
                        } else {
                                instr.integer =
                                        fmt1_ins->immediate
                                      | (fmt1_ins->source << 8)
                                      | (fmt1_ins->destination << 16)
                                      |        (fmt1_ins->ret << 24)
                                      |        (fmt1_ins->opcode << 25);
                        }
                }
                /* The sequencer is a little endian cpu */
                instr.integer = ahc_htole32(instr.integer);
                ahc_outsb(ahc, SEQRAM, instr.bytes, 4);
                break;
        default:
                panic("Unknown opcode encountered in seq program");
                break;
        }
}

int
ahc_print_register(const ahc_reg_parse_entry_t *table, u_int num_entries,
                   const char *name, u_int address, u_int value,
                   u_int *cur_column, u_int wrap_point)
{
        int        printed;
        u_int        printed_mask;

        if (cur_column != NULL && *cur_column >= wrap_point) {
                printf("\n");
                *cur_column = 0;
        }
        printed = printf("%s[0x%x]", name, value);
        if (table == NULL) {
                printed += printf(" ");
                *cur_column += printed;
                return (printed);
        }
        printed_mask = 0;
        while (printed_mask != 0xFF) {
                int entry;

                for (entry = 0; entry < num_entries; entry++) {
                        if (((value & table[entry].mask)
                          != table[entry].value)
                         || ((printed_mask & table[entry].mask)
                          == table[entry].mask))
                                continue;

                        printed += printf("%s%s",
                                          printed_mask == 0 ? ":(" : "|",
                                          table[entry].name);
                        printed_mask |= table[entry].mask;
                        
                        break;
                }
                if (entry >= num_entries)
                        break;
        }
        if (printed_mask != 0)
                printed += printf(") ");
        else
                printed += printf(" ");
        if (cur_column != NULL)
                *cur_column += printed;
        return (printed);
}

void
ahc_dump_card_state(struct ahc_softc *ahc)
{
        struct        scb *scb;
        struct        scb_tailq *untagged_q;
        u_int        cur_col;
        int        paused;
        int        target;
        int        maxtarget;
        int        i;
        uint8_t last_phase;
        uint8_t qinpos;
        uint8_t qintail;
        uint8_t qoutpos;
        uint8_t scb_index;
        uint8_t saved_scbptr;

        if (ahc_is_paused(ahc)) {
                paused = 1;
        } else {
                paused = 0;
                ahc_pause(ahc);
        }

        saved_scbptr = ahc_inb(ahc, SCBPTR);
        last_phase = ahc_inb(ahc, LASTPHASE);
        printf(">>>>>>>>>>>>>>>>>> Dump Card State Begins <<<<<<<<<<<<<<<<<\n"
               "%s: Dumping Card State %s, at SEQADDR 0x%x\n",
               ahc_name(ahc), ahc_lookup_phase_entry(last_phase)->phasemsg,
               ahc_inb(ahc, SEQADDR0) | (ahc_inb(ahc, SEQADDR1) << 8));
        if (paused)
                printf("Card was paused\n");
        printf("ACCUM = 0x%x, SINDEX = 0x%x, DINDEX = 0x%x, ARG_2 = 0x%x\n",
               ahc_inb(ahc, ACCUM), ahc_inb(ahc, SINDEX), ahc_inb(ahc, DINDEX),
               ahc_inb(ahc, ARG_2));
        printf("HCNT = 0x%x SCBPTR = 0x%x\n", ahc_inb(ahc, HCNT),
               ahc_inb(ahc, SCBPTR));
        cur_col = 0;
        if ((ahc->features & AHC_DT) != 0)
                ahc_scsiphase_print(ahc_inb(ahc, SCSIPHASE), &cur_col, 50);
        ahc_scsisigi_print(ahc_inb(ahc, SCSISIGI), &cur_col, 50);
        ahc_error_print(ahc_inb(ahc, ERROR), &cur_col, 50);
        ahc_scsibusl_print(ahc_inb(ahc, SCSIBUSL), &cur_col, 50);
        ahc_lastphase_print(ahc_inb(ahc, LASTPHASE), &cur_col, 50);
        ahc_scsiseq_print(ahc_inb(ahc, SCSISEQ), &cur_col, 50);
        ahc_sblkctl_print(ahc_inb(ahc, SBLKCTL), &cur_col, 50);
        ahc_scsirate_print(ahc_inb(ahc, SCSIRATE), &cur_col, 50);
        ahc_seqctl_print(ahc_inb(ahc, SEQCTL), &cur_col, 50);
        ahc_seq_flags_print(ahc_inb(ahc, SEQ_FLAGS), &cur_col, 50);
        ahc_sstat0_print(ahc_inb(ahc, SSTAT0), &cur_col, 50);
        ahc_sstat1_print(ahc_inb(ahc, SSTAT1), &cur_col, 50);
        ahc_sstat2_print(ahc_inb(ahc, SSTAT2), &cur_col, 50);
        ahc_sstat3_print(ahc_inb(ahc, SSTAT3), &cur_col, 50);
        ahc_simode0_print(ahc_inb(ahc, SIMODE0), &cur_col, 50);
        ahc_simode1_print(ahc_inb(ahc, SIMODE1), &cur_col, 50);
        ahc_sxfrctl0_print(ahc_inb(ahc, SXFRCTL0), &cur_col, 50);
        ahc_dfcntrl_print(ahc_inb(ahc, DFCNTRL), &cur_col, 50);
        ahc_dfstatus_print(ahc_inb(ahc, DFSTATUS), &cur_col, 50);
        if (cur_col != 0)
                printf("\n");
        printf("STACK:");
        for (i = 0; i < STACK_SIZE; i++)
               printf(" 0x%x", ahc_inb(ahc, STACK)|(ahc_inb(ahc, STACK) << 8));
        printf("\nSCB count = %d\n", ahc->scb_data->numscbs);
        printf("Kernel NEXTQSCB = %d\n", ahc->next_queued_scb->hscb->tag);
        printf("Card NEXTQSCB = %d\n", ahc_inb(ahc, NEXT_QUEUED_SCB));
        /* QINFIFO */
        printf("QINFIFO entries: ");
        if ((ahc->features & AHC_QUEUE_REGS) != 0) {
                qinpos = ahc_inb(ahc, SNSCB_QOFF);
                ahc_outb(ahc, SNSCB_QOFF, qinpos);
        } else
                qinpos = ahc_inb(ahc, QINPOS);
        qintail = ahc->qinfifonext;
        while (qinpos != qintail) {
                printf("%d ", ahc->qinfifo[qinpos]);
                qinpos++;
        }
        printf("\n");

        printf("Waiting Queue entries: ");
        scb_index = ahc_inb(ahc, WAITING_SCBH);
        i = 0;
        while (scb_index != SCB_LIST_NULL && i++ < 256) {
                ahc_outb(ahc, SCBPTR, scb_index);
                printf("%d:%d ", scb_index, ahc_inb(ahc, SCB_TAG));
                scb_index = ahc_inb(ahc, SCB_NEXT);
        }
        printf("\n");

        printf("Disconnected Queue entries: ");
        scb_index = ahc_inb(ahc, DISCONNECTED_SCBH);
        i = 0;
        while (scb_index != SCB_LIST_NULL && i++ < 256) {
                ahc_outb(ahc, SCBPTR, scb_index);
                printf("%d:%d ", scb_index, ahc_inb(ahc, SCB_TAG));
                scb_index = ahc_inb(ahc, SCB_NEXT);
        }
        printf("\n");
                
        ahc_sync_qoutfifo(ahc, BUS_DMASYNC_POSTREAD);
        printf("QOUTFIFO entries: ");
        qoutpos = ahc->qoutfifonext;
        i = 0;
        while (ahc->qoutfifo[qoutpos] != SCB_LIST_NULL && i++ < 256) {
                printf("%d ", ahc->qoutfifo[qoutpos]);
                qoutpos++;
        }
        printf("\n");

        printf("Sequencer Free SCB List: ");
        scb_index = ahc_inb(ahc, FREE_SCBH);
        i = 0;
        while (scb_index != SCB_LIST_NULL && i++ < 256) {
                ahc_outb(ahc, SCBPTR, scb_index);
                printf("%d ", scb_index);
                scb_index = ahc_inb(ahc, SCB_NEXT);
        }
        printf("\n");

        printf("Sequencer SCB Info: ");
        for (i = 0; i < ahc->scb_data->maxhscbs; i++) {
                ahc_outb(ahc, SCBPTR, i);
                cur_col = printf("\n%3d ", i);

                ahc_scb_control_print(ahc_inb(ahc, SCB_CONTROL), &cur_col, 60);
                ahc_scb_scsiid_print(ahc_inb(ahc, SCB_SCSIID), &cur_col, 60);
                ahc_scb_lun_print(ahc_inb(ahc, SCB_LUN), &cur_col, 60);
                ahc_scb_tag_print(ahc_inb(ahc, SCB_TAG), &cur_col, 60);
        }
        printf("\n");

        printf("Pending list: ");
        i = 0;
        LIST_FOREACH(scb, &ahc->pending_scbs, pending_links) {
                if (i++ > 256)
                        break;
                cur_col = printf("\n%3d ", scb->hscb->tag);
                ahc_scb_control_print(scb->hscb->control, &cur_col, 60);
                ahc_scb_scsiid_print(scb->hscb->scsiid, &cur_col, 60);
                ahc_scb_lun_print(scb->hscb->lun, &cur_col, 60);
                if ((ahc->flags & AHC_PAGESCBS) == 0) {
                        ahc_outb(ahc, SCBPTR, scb->hscb->tag);
                        printf("(");
                        ahc_scb_control_print(ahc_inb(ahc, SCB_CONTROL),
                                              &cur_col, 60);
                        ahc_scb_tag_print(ahc_inb(ahc, SCB_TAG), &cur_col, 60);
                        printf(")");
                }
        }
        printf("\n");

        printf("Kernel Free SCB list: ");
        i = 0;
        SLIST_FOREACH(scb, &ahc->scb_data->free_scbs, links.sle) {
                if (i++ > 256)
                        break;
                printf("%d ", scb->hscb->tag);
        }
        printf("\n");

        maxtarget = (ahc->features & (AHC_WIDE|AHC_TWIN)) ? 15 : 7;
        for (target = 0; target <= maxtarget; target++) {
                untagged_q = &ahc->untagged_queues[target];
                if (TAILQ_FIRST(untagged_q) == NULL)
                        continue;
                printf("Untagged Q(%d): ", target);
                i = 0;
                TAILQ_FOREACH(scb, untagged_q, links.tqe) {
                        if (i++ > 256)
                                break;
                        printf("%d ", scb->hscb->tag);
                }
                printf("\n");
        }

        ahc_platform_dump_card_state(ahc);
        printf("\n<<<<<<<<<<<<<<<<< Dump Card State Ends >>>>>>>>>>>>>>>>>>\n");
        ahc_outb(ahc, SCBPTR, saved_scbptr);
        if (paused == 0)
                ahc_unpause(ahc);
}

/************************* Target Mode ****************************************/
#ifdef AHC_TARGET_MODE
cam_status
ahc_find_tmode_devs(struct ahc_softc *ahc, struct cam_sim *sim, union ccb *ccb,
                    struct ahc_tmode_tstate **tstate,
                    struct ahc_tmode_lstate **lstate,
                    int notfound_failure)
{

        if ((ahc->features & AHC_TARGETMODE) == 0)
                return (CAM_REQ_INVALID);

        /*
         * Handle the 'black hole' device that sucks up
         * requests to unattached luns on enabled targets.
         */
        if (ccb->ccb_h.target_id == CAM_TARGET_WILDCARD
         && ccb->ccb_h.target_lun == CAM_LUN_WILDCARD) {
                *tstate = NULL;
                *lstate = ahc->black_hole;
        } else {
                u_int max_id;

                max_id = (ahc->features & AHC_WIDE) ? 16 : 8;
                if (ccb->ccb_h.target_id >= max_id)
                        return (CAM_TID_INVALID);

                if (ccb->ccb_h.target_lun >= AHC_NUM_LUNS)
                        return (CAM_LUN_INVALID);

                *tstate = ahc->enabled_targets[ccb->ccb_h.target_id];
                *lstate = NULL;
                if (*tstate != NULL)
                        *lstate =
                            (*tstate)->enabled_luns[ccb->ccb_h.target_lun];
        }

        if (notfound_failure != 0 && *lstate == NULL)
                return (CAM_PATH_INVALID);

        return (CAM_REQ_CMP);
}

void
ahc_handle_en_lun(struct ahc_softc *ahc, struct cam_sim *sim, union ccb *ccb)
{
        struct           ahc_tmode_tstate *tstate;
        struct           ahc_tmode_lstate *lstate;
        struct           ccb_en_lun *cel;
        cam_status status;
        u_long           s;
        u_int           target;
        u_int           lun;
        u_int           target_mask;
        u_int           our_id;
        int           error;
        char           channel;

        status = ahc_find_tmode_devs(ahc, sim, ccb, &tstate, &lstate,
                                     /*notfound_failure*/FALSE);

        if (status != CAM_REQ_CMP) {
                ccb->ccb_h.status = status;
                return;
        }

        if (cam_sim_bus(sim) == 0)
                our_id = ahc->our_id;
        else
                our_id = ahc->our_id_b;

        if (ccb->ccb_h.target_id != our_id) {
                /*
                 * our_id represents our initiator ID, or
                 * the ID of the first target to have an
                 * enabled lun in target mode.  There are
                 * two cases that may preclude enabling a
                 * target id other than our_id.
                 *
                 *   o our_id is for an active initiator role.
                 *     Since the hardware does not support
                 *     reselections to the initiator role at
                 *     anything other than our_id, and our_id
                 *     is used by the hardware to indicate the
                 *     ID to use for both select-out and
                 *     reselect-out operations, the only target
                 *     ID we can support in this mode is our_id.
                 *
                 *   o The MULTARGID feature is not available and
                 *     a previous target mode ID has been enabled.
                 */
                if ((ahc->features & AHC_MULTIROLE) != 0) {

                        if ((ahc->features & AHC_MULTI_TID) != 0
                            && (ahc->flags & AHC_INITIATORROLE) != 0) {
                                /*
                                 * Only allow additional targets if
                                 * the initiator role is disabled.
                                 * The hardware cannot handle a re-select-in
                                 * on the initiator id during a re-select-out
                                 * on a different target id.
                                 */
                                status = CAM_TID_INVALID;
                        } else if ((ahc->flags & AHC_INITIATORROLE) != 0
                                || ahc->enabled_luns > 0) {
                                /*
                                 * Only allow our target id to change
                                 * if the initiator role is not configured
                                 * and there are no enabled luns which
                                 * are attached to the currently registered
                                 * scsi id.
                                 */
                                status = CAM_TID_INVALID;
                        }
                } else if ((ahc->features & AHC_MULTI_TID) == 0
                        && ahc->enabled_luns > 0) {

                        status = CAM_TID_INVALID;
                }
        }

        if (status != CAM_REQ_CMP) {
                ccb->ccb_h.status = status;
                return;
        }

        /*
         * We now have an id that is valid.
         * If we aren't in target mode, switch modes.
         */
        if ((ahc->flags & AHC_TARGETROLE) == 0
         && ccb->ccb_h.target_id != CAM_TARGET_WILDCARD) {
                u_long         s;
                ahc_flag saved_flags;

                printf("Configuring Target Mode\n");
                ahc_lock(ahc, &s);
                if (LIST_FIRST(&ahc->pending_scbs) != NULL) {
                        ccb->ccb_h.status = CAM_BUSY;
                        ahc_unlock(ahc, &s);
                        return;
                }
                saved_flags = ahc->flags;
                ahc->flags |= AHC_TARGETROLE;
                if ((ahc->features & AHC_MULTIROLE) == 0)
                        ahc->flags &= ~AHC_INITIATORROLE;
                ahc_pause(ahc);
                error = ahc_loadseq(ahc);
                if (error != 0) {
                        /*
                         * Restore original configuration and notify
                         * the caller that we cannot support target mode.
                         * Since the adapter started out in this
                         * configuration, the firmware load will succeed,
                         * so there is no point in checking ahc_loadseq's
                         * return value.
                         */
                        ahc->flags = saved_flags;
                        (void)ahc_loadseq(ahc);
                        ahc_restart(ahc);
                        ahc_unlock(ahc, &s);
                        ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
                        return;
                }
                ahc_restart(ahc);
                ahc_unlock(ahc, &s);
        }
        cel = &ccb->cel;
        target = ccb->ccb_h.target_id;
        lun = ccb->ccb_h.target_lun;
        channel = SIM_CHANNEL(ahc, sim);
        target_mask = 0x01 << target;
        if (channel == 'B')
                target_mask <<= 8;

        if (cel->enable != 0) {
                u_int scsiseq;

                /* Are we already enabled?? */
                if (lstate != NULL) {
                        xpt_print_path(ccb->ccb_h.path);
                        printf("Lun already enabled\n");
                        ccb->ccb_h.status = CAM_LUN_ALRDY_ENA;
                        return;
                }

                if (cel->grp6_len != 0
                 || cel->grp7_len != 0) {
                        /*
                         * Don't (yet?) support vendor
                         * specific commands.
                         */
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                        printf("Non-zero Group Codes\n");
                        return;
                }

                /*
                 * Seems to be okay.
                 * Setup our data structures.
                 */
                if (target != CAM_TARGET_WILDCARD && tstate == NULL) {
                        tstate = ahc_alloc_tstate(ahc, target, channel);
                        if (tstate == NULL) {
                                xpt_print_path(ccb->ccb_h.path);
                                printf("Couldn't allocate tstate\n");
                                ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                                return;
                        }
                }
                lstate = malloc(sizeof(*lstate), M_DEVBUF, M_NOWAIT);
                if (lstate == NULL) {
                        xpt_print_path(ccb->ccb_h.path);
                        printf("Couldn't allocate lstate\n");
                        ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                        return;
                }
                memset(lstate, 0, sizeof(*lstate));
                status = xpt_create_path(&lstate->path, /*periph*/NULL,
                                         xpt_path_path_id(ccb->ccb_h.path),
                                         xpt_path_target_id(ccb->ccb_h.path),
                                         xpt_path_lun_id(ccb->ccb_h.path));
                if (status != CAM_REQ_CMP) {
                        free(lstate, M_DEVBUF);
                        xpt_print_path(ccb->ccb_h.path);
                        printf("Couldn't allocate path\n");
                        ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                        return;
                }
                SLIST_INIT(&lstate->accept_tios);
                SLIST_INIT(&lstate->immed_notifies);
                ahc_lock(ahc, &s);
                ahc_pause(ahc);
                if (target != CAM_TARGET_WILDCARD) {
                        tstate->enabled_luns[lun] = lstate;
                        ahc->enabled_luns++;

                        if ((ahc->features & AHC_MULTI_TID) != 0) {
                                u_int targid_mask;

                                targid_mask = ahc_inb(ahc, TARGID)
                                            | (ahc_inb(ahc, TARGID + 1) << 8);

                                targid_mask |= target_mask;
                                ahc_outb(ahc, TARGID, targid_mask);
                                ahc_outb(ahc, TARGID+1, (targid_mask >> 8));
                                
                                ahc_update_scsiid(ahc, targid_mask);
                        } else {
                                u_int our_id;
                                char  channel;

                                channel = SIM_CHANNEL(ahc, sim);
                                our_id = SIM_SCSI_ID(ahc, sim);

                                /*
                                 * This can only happen if selections
                                 * are not enabled
                                 */
                                if (target != our_id) {
                                        u_int sblkctl;
                                        char  cur_channel;
                                        int   swap;

                                        sblkctl = ahc_inb(ahc, SBLKCTL);
                                        cur_channel = (sblkctl & SELBUSB)
                                                    ? 'B' : 'A';
                                        if ((ahc->features & AHC_TWIN) == 0)
                                                cur_channel = 'A';
                                        swap = cur_channel != channel;
                                        if (channel == 'A')
                                                ahc->our_id = target;
                                        else
                                                ahc->our_id_b = target;

                                        if (swap)
                                                ahc_outb(ahc, SBLKCTL,
                                                         sblkctl ^ SELBUSB);

                                        ahc_outb(ahc, SCSIID, target);

                                        if (swap)
                                                ahc_outb(ahc, SBLKCTL, sblkctl);
                                }
                        }
                } else
                        ahc->black_hole = lstate;
                /* Allow select-in operations */
                if (ahc->black_hole != NULL && ahc->enabled_luns > 0) {
                        scsiseq = ahc_inb(ahc, SCSISEQ_TEMPLATE);
                        scsiseq |= ENSELI;
                        ahc_outb(ahc, SCSISEQ_TEMPLATE, scsiseq);
                        scsiseq = ahc_inb(ahc, SCSISEQ);
                        scsiseq |= ENSELI;
                        ahc_outb(ahc, SCSISEQ, scsiseq);
                }
                ahc_unpause(ahc);
                ahc_unlock(ahc, &s);
                ccb->ccb_h.status = CAM_REQ_CMP;
                xpt_print_path(ccb->ccb_h.path);
                printf("Lun now enabled for target mode\n");
        } else {
                struct scb *scb;
                int i, empty;

                if (lstate == NULL) {
                        ccb->ccb_h.status = CAM_LUN_INVALID;
                        return;
                }

                ahc_lock(ahc, &s);
                
                ccb->ccb_h.status = CAM_REQ_CMP;
                LIST_FOREACH(scb, &ahc->pending_scbs, pending_links) {
                        struct ccb_hdr *ccbh;

                        ccbh = &scb->io_ctx->ccb_h;
                        if (ccbh->func_code == XPT_CONT_TARGET_IO
                         && !xpt_path_comp(ccbh->path, ccb->ccb_h.path)){
                                printf("CTIO pending\n");
                                ccb->ccb_h.status = CAM_REQ_INVALID;
                                ahc_unlock(ahc, &s);
                                return;
                        }
                }

                if (SLIST_FIRST(&lstate->accept_tios) != NULL) {
                        printf("ATIOs pending\n");
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                }

                if (SLIST_FIRST(&lstate->immed_notifies) != NULL) {
                        printf("INOTs pending\n");
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                }

                if (ccb->ccb_h.status != CAM_REQ_CMP) {
                        ahc_unlock(ahc, &s);
                        return;
                }

                xpt_print_path(ccb->ccb_h.path);
                printf("Target mode disabled\n");
                xpt_free_path(lstate->path);
                free(lstate, M_DEVBUF);

                ahc_pause(ahc);
                /* Can we clean up the target too? */
                if (target != CAM_TARGET_WILDCARD) {
                        tstate->enabled_luns[lun] = NULL;
                        ahc->enabled_luns--;
                        for (empty = 1, i = 0; i < 8; i++)
                                if (tstate->enabled_luns[i] != NULL) {
                                        empty = 0;
                                        break;
                                }

                        if (empty) {
                                ahc_free_tstate(ahc, target, channel,
                                                /*force*/FALSE);
                                if (ahc->features & AHC_MULTI_TID) {
                                        u_int targid_mask;

                                        targid_mask = ahc_inb(ahc, TARGID)
                                                    | (ahc_inb(ahc, TARGID + 1)
                                                       << 8);

                                        targid_mask &= ~target_mask;
                                        ahc_outb(ahc, TARGID, targid_mask);
                                        ahc_outb(ahc, TARGID+1,
                                                  (targid_mask >> 8));
                                        ahc_update_scsiid(ahc, targid_mask);
                                }
                        }
                } else {

                        ahc->black_hole = NULL;

                        /*
                         * We can't allow selections without
                         * our black hole device.
                         */
                        empty = TRUE;
                }
                if (ahc->enabled_luns == 0) {
                        /* Disallow select-in */
                        u_int scsiseq;

                        scsiseq = ahc_inb(ahc, SCSISEQ_TEMPLATE);
                        scsiseq &= ~ENSELI;
                        ahc_outb(ahc, SCSISEQ_TEMPLATE, scsiseq);
                        scsiseq = ahc_inb(ahc, SCSISEQ);
                        scsiseq &= ~ENSELI;
                        ahc_outb(ahc, SCSISEQ, scsiseq);

                        if ((ahc->features & AHC_MULTIROLE) == 0) {
                                printf("Configuring Initiator Mode\n");
                                ahc->flags &= ~AHC_TARGETROLE;
                                ahc->flags |= AHC_INITIATORROLE;
                                /*
                                 * Returning to a configuration that
                                 * fit previously will always succeed.
                                 */
                                (void)ahc_loadseq(ahc);
                                ahc_restart(ahc);
                                /*
                                 * Unpaused.  The extra unpause
                                 * that follows is harmless.
                                 */
                        }
                }
                ahc_unpause(ahc);
                ahc_unlock(ahc, &s);
        }
}

static void
ahc_update_scsiid(struct ahc_softc *ahc, u_int targid_mask)
{
        u_int scsiid_mask;
        u_int scsiid;

        if ((ahc->features & AHC_MULTI_TID) == 0)
                panic("ahc_update_scsiid called on non-multitid unit\n");

        /*
         * Since we will rely on the TARGID mask
         * for selection enables, ensure that OID
         * in SCSIID is not set to some other ID
         * that we don't want to allow selections on.
         */
        if ((ahc->features & AHC_ULTRA2) != 0)
                scsiid = ahc_inb(ahc, SCSIID_ULTRA2);
        else
                scsiid = ahc_inb(ahc, SCSIID);
        scsiid_mask = 0x1 << (scsiid & OID);
        if ((targid_mask & scsiid_mask) == 0) {
                u_int our_id;

                /* ffs counts from 1 */
                our_id = ffs(targid_mask);
                if (our_id == 0)
                        our_id = ahc->our_id;
                else
                        our_id--;
                scsiid &= TID;
                scsiid |= our_id;
        }
        if ((ahc->features & AHC_ULTRA2) != 0)
                ahc_outb(ahc, SCSIID_ULTRA2, scsiid);
        else
                ahc_outb(ahc, SCSIID, scsiid);
}

static void
ahc_run_tqinfifo(struct ahc_softc *ahc, int paused)
{
        struct target_cmd *cmd;

        /*
         * If the card supports auto-access pause,
         * we can access the card directly regardless
         * of whether it is paused or not.
         */
        if ((ahc->features & AHC_AUTOPAUSE) != 0)
                paused = TRUE;

        ahc_sync_tqinfifo(ahc, BUS_DMASYNC_POSTREAD);
        while ((cmd = &ahc->targetcmds[ahc->tqinfifonext])->cmd_valid != 0) {

                /*
                 * Only advance through the queue if we
                 * have the resources to process the command.
                 */
                if (ahc_handle_target_cmd(ahc, cmd) != 0)
                        break;

                cmd->cmd_valid = 0;
                ahc_dmamap_sync(ahc, ahc->shared_data_dmat,
                                ahc->shared_data_dmamap,
                                ahc_targetcmd_offset(ahc, ahc->tqinfifonext),
                                sizeof(struct target_cmd),
                                BUS_DMASYNC_PREREAD);
                ahc->tqinfifonext++;

                /*
                 * Lazily update our position in the target mode incoming
                 * command queue as seen by the sequencer.
                 */
                if ((ahc->tqinfifonext & (HOST_TQINPOS - 1)) == 1) {
                        if ((ahc->features & AHC_HS_MAILBOX) != 0) {
                                u_int hs_mailbox;

                                hs_mailbox = ahc_inb(ahc, HS_MAILBOX);
                                hs_mailbox &= ~HOST_TQINPOS;
                                hs_mailbox |= ahc->tqinfifonext & HOST_TQINPOS;
                                ahc_outb(ahc, HS_MAILBOX, hs_mailbox);
                        } else {
                                if (!paused)
                                        ahc_pause(ahc);        
                                ahc_outb(ahc, KERNEL_TQINPOS,
                                         ahc->tqinfifonext & HOST_TQINPOS);
                                if (!paused)
                                        ahc_unpause(ahc);
                        }
                }
        }
}

static int
ahc_handle_target_cmd(struct ahc_softc *ahc, struct target_cmd *cmd)
{
        struct          ahc_tmode_tstate *tstate;
        struct          ahc_tmode_lstate *lstate;
        struct          ccb_accept_tio *atio;
        uint8_t *byte;
        int          initiator;
        int          target;
        int          lun;

        initiator = SCSIID_TARGET(ahc, cmd->scsiid);
        target = SCSIID_OUR_ID(cmd->scsiid);
        lun    = (cmd->identify & MSG_IDENTIFY_LUNMASK);

        byte = cmd->bytes;
        tstate = ahc->enabled_targets[target];
        lstate = NULL;
        if (tstate != NULL)
                lstate = tstate->enabled_luns[lun];

        /*
         * Commands for disabled luns go to the black hole driver.
         */
        if (lstate == NULL)
                lstate = ahc->black_hole;

        atio = (struct ccb_accept_tio*)SLIST_FIRST(&lstate->accept_tios);
        if (atio == NULL) {
                ahc->flags |= AHC_TQINFIFO_BLOCKED;
                /*
                 * Wait for more ATIOs from the peripheral driver for this lun.
                 */
                if (bootverbose)
                        printf("%s: ATIOs exhausted\n", ahc_name(ahc));
                return (1);
        } else
                ahc->flags &= ~AHC_TQINFIFO_BLOCKED;
#if 0
        printf("Incoming command from %d for %d:%d%s\n",
               initiator, target, lun,
               lstate == ahc->black_hole ? "(Black Holed)" : "");
#endif
        SLIST_REMOVE_HEAD(&lstate->accept_tios, sim_links.sle);

        if (lstate == ahc->black_hole) {
                /* Fill in the wildcards */
                atio->ccb_h.target_id = target;
                atio->ccb_h.target_lun = lun;
        }

        /*
         * Package it up and send it off to
         * whomever has this lun enabled.
         */
        atio->sense_len = 0;
        atio->init_id = initiator;
        if (byte[0] != 0xFF) {
                /* Tag was included */
                atio->tag_action = *byte++;
                atio->tag_id = *byte++;
                atio->ccb_h.flags = CAM_TAG_ACTION_VALID;
        } else {
                atio->ccb_h.flags = 0;
        }
        byte++;

        /* Okay.  Now determine the cdb size based on the command code */
        switch (*byte >> CMD_GROUP_CODE_SHIFT) {
        case 0:
                atio->cdb_len = 6;
                break;
        case 1:
        case 2:
                atio->cdb_len = 10;
                break;
        case 4:
                atio->cdb_len = 16;
                break;
        case 5:
                atio->cdb_len = 12;
                break;
        case 3:
        default:
                /* Only copy the opcode. */
                atio->cdb_len = 1;
                printf("Reserved or VU command code type encountered\n");
                break;
        }
        
        memcpy(atio->cdb_io.cdb_bytes, byte, atio->cdb_len);

        atio->ccb_h.status |= CAM_CDB_RECVD;

        if ((cmd->identify & MSG_IDENTIFY_DISCFLAG) == 0) {
                /*
                 * We weren't allowed to disconnect.
                 * We're hanging on the bus until a
                 * continue target I/O comes in response
                 * to this accept tio.
                 */
#if 0
                printf("Received Immediate Command %d:%d:%d - %p\n",
                       initiator, target, lun, ahc->pending_device);
#endif
                ahc->pending_device = lstate;
                ahc_freeze_ccb((union ccb *)atio);
                atio->ccb_h.flags |= CAM_DIS_DISCONNECT;
        }
        xpt_done((union ccb*)atio);
        return (0);
}

#endif