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   /* sbni.c:  Granch SBNI12 leased line adapters driver for linux
    *
    *        Written 2001 by Denis I.Timofeev (timofeev@granch.ru)
    *
    *        Previous versions were written by Yaroslav Polyakov,
    *        Alexey Zverev and Max Khon.
    *
    *        Driver supports SBNI12-02,-04,-05,-10,-11 cards, single and
    *        double-channel, PCI and ISA modifications.
   *        More info and useful utilities to work with SBNI12 cards you can find
   *        at http://www.granch.com (English) or http://www.granch.ru (Russian)
   *
   *        This software may be used and distributed according to the terms
   *        of the GNU General Public License.
   *
   *
   *  5.0.1        Jun 22 2001
   *          - Fixed bug in probe
   *  5.0.0        Jun 06 2001
   *          - Driver was completely redesigned by Denis I.Timofeev,
   *          - now PCI/Dual, ISA/Dual (with single interrupt line) models are
   *          - supported
   *  3.3.0        Thu Feb 24 21:30:28 NOVT 2000 
   *        - PCI cards support
   *  3.2.0        Mon Dec 13 22:26:53 NOVT 1999
   *           - Completely rebuilt all the packet storage system
   *           -    to work in Ethernet-like style.
   *  3.1.1        just fixed some bugs (5 aug 1999)
   *  3.1.0        added balancing feature        (26 apr 1999)
   *  3.0.1        just fixed some bugs (14 apr 1999).
   *  3.0.0        Initial Revision, Yaroslav Polyakov (24 Feb 1999)
   *        - added pre-calculation for CRC, fixed bug with "len-2" frames, 
   *        - removed outbound fragmentation (MTU=1000), written CRC-calculation 
   *        - on asm, added work with hard_headers and now we have our own cache 
   *        - for them, optionally supported word-interchange on some chipsets,
   * 
   *        Known problem: this driver wasn't tested on multiprocessor machine.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/ptrace.h>
  #include <linux/fcntl.h>
  #include <linux/ioport.h>
  #include <linux/interrupt.h>
  #include <linux/slab.h>
  #include <linux/string.h>
  #include <linux/errno.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/pci.h>
  #include <linux/skbuff.h>
  #include <linux/timer.h>
  #include <linux/init.h>
  #include <linux/delay.h>
  
  #include <net/net_namespace.h>
  #include <net/arp.h>
  
  #include <asm/io.h>
  #include <asm/types.h>
  #include <asm/byteorder.h>
  #include <asm/irq.h>
  #include <asm/uaccess.h>
  
  #include "sbni.h"
  
  /* device private data */
  
  struct net_local {
          struct net_device_stats        stats;
          struct timer_list        watchdog;
  
          spinlock_t        lock;
          struct sk_buff  *rx_buf_p;                /* receive buffer ptr */
          struct sk_buff  *tx_buf_p;                /* transmit buffer ptr */
          
          unsigned int        framelen;                /* current frame length */
          unsigned int        maxframe;                /* maximum valid frame length */
          unsigned int        state;
          unsigned int        inppos, outpos;                /* positions in rx/tx buffers */
  
          /* transmitting frame number - from frames qty to 1 */
          unsigned int        tx_frameno;
  
          /* expected number of next receiving frame */
          unsigned int        wait_frameno;
  
          /* count of failed attempts to frame send - 32 attempts do before
             error - while receiver tunes on opposite side of wire */
          unsigned int        trans_errors;
  
          /* idle time; send pong when limit exceeded */
          unsigned int        timer_ticks;
  
          /* fields used for receive level autoselection */
          int        delta_rxl;
          unsigned int        cur_rxl_index, timeout_rxl;
          unsigned long        cur_rxl_rcvd, prev_rxl_rcvd;
 
         struct sbni_csr1        csr1;                /* current value of CSR1 */
         struct sbni_in_stats        in_stats;         /* internal statistics */ 
 
         struct net_device                *second;        /* for ISA/dual cards */
 
 #ifdef CONFIG_SBNI_MULTILINE
         struct net_device                *master;
         struct net_device                *link;
 #endif
 };
 
 
 static int  sbni_card_probe( unsigned long );
 static int  sbni_pci_probe( struct net_device  * );
 static struct net_device  *sbni_probe1(struct net_device *, unsigned long, int);
 static int  sbni_open( struct net_device * );
 static int  sbni_close( struct net_device * );
 static int  sbni_start_xmit( struct sk_buff *, struct net_device * );
 static int  sbni_ioctl( struct net_device *, struct ifreq *, int );
 static struct net_device_stats  *sbni_get_stats( struct net_device * );
 static void  set_multicast_list( struct net_device * );
 
 static irqreturn_t sbni_interrupt( int, void * );
 static void  handle_channel( struct net_device * );
 static int   recv_frame( struct net_device * );
 static void  send_frame( struct net_device * );
 static int   upload_data( struct net_device *,
                           unsigned, unsigned, unsigned, u32 );
 static void  download_data( struct net_device *, u32 * );
 static void  sbni_watchdog( unsigned long );
 static void  interpret_ack( struct net_device *, unsigned );
 static int   append_frame_to_pkt( struct net_device *, unsigned, u32 );
 static void  indicate_pkt( struct net_device * );
 static void  card_start( struct net_device * );
 static void  prepare_to_send( struct sk_buff *, struct net_device * );
 static void  drop_xmit_queue( struct net_device * );
 static void  send_frame_header( struct net_device *, u32 * );
 static int   skip_tail( unsigned int, unsigned int, u32 );
 static int   check_fhdr( u32, u32 *, u32 *, u32 *, u32 *, u32 * );
 static void  change_level( struct net_device * );
 static void  timeout_change_level( struct net_device * );
 static u32   calc_crc32( u32, u8 *, u32 );
 static struct sk_buff *  get_rx_buf( struct net_device * );
 static int  sbni_init( struct net_device * );
 
 #ifdef CONFIG_SBNI_MULTILINE
 static int  enslave( struct net_device *, struct net_device * );
 static int  emancipate( struct net_device * );
 #endif
 
 #ifdef __i386__
 #define ASM_CRC 1
 #endif
 
 static const char  version[] =
         "Granch SBNI12 driver ver 5.0.1  Jun 22 2001  Denis I.Timofeev.\n";
 
 static int  skip_pci_probe        __initdata = 0;
 static int  scandone        __initdata = 0;
 static int  num                __initdata = 0;
 
 static unsigned char  rxl_tab[];
 static u32  crc32tab[];
 
 /* A list of all installed devices, for removing the driver module. */
 static struct net_device  *sbni_cards[ SBNI_MAX_NUM_CARDS ];
 
 /* Lists of device's parameters */
 static u32        io[   SBNI_MAX_NUM_CARDS ] __initdata =
         { [0 ... SBNI_MAX_NUM_CARDS-1] = -1 };
 static u32        irq[  SBNI_MAX_NUM_CARDS ] __initdata;
 static u32        baud[ SBNI_MAX_NUM_CARDS ] __initdata;
 static u32        rxl[  SBNI_MAX_NUM_CARDS ] __initdata =
         { [0 ... SBNI_MAX_NUM_CARDS-1] = -1 };
 static u32        mac[  SBNI_MAX_NUM_CARDS ] __initdata;
 
 #ifndef MODULE
 typedef u32  iarr[];
 static iarr __initdata *dest[5] = { &io, &irq, &baud, &rxl, &mac };
 #endif
 
 /* A zero-terminated list of I/O addresses to be probed on ISA bus */
 static unsigned int  netcard_portlist[ ] __initdata = { 
         0x210, 0x214, 0x220, 0x224, 0x230, 0x234, 0x240, 0x244, 0x250, 0x254,
         0x260, 0x264, 0x270, 0x274, 0x280, 0x284, 0x290, 0x294, 0x2a0, 0x2a4,
         0x2b0, 0x2b4, 0x2c0, 0x2c4, 0x2d0, 0x2d4, 0x2e0, 0x2e4, 0x2f0, 0x2f4,
         0 };
 
 
 /*
  * Look for SBNI card which addr stored in dev->base_addr, if nonzero.
  * Otherwise, look through PCI bus. If none PCI-card was found, scan ISA.
  */
 
 static inline int __init
 sbni_isa_probe( struct net_device  *dev )
 {
         if( dev->base_addr > 0x1ff
             &&  request_region( dev->base_addr, SBNI_IO_EXTENT, dev->name )
             &&  sbni_probe1( dev, dev->base_addr, dev->irq ) )
 
                 return  0;
         else {
                 printk( KERN_ERR "sbni: base address 0x%lx is busy, or adapter "
                         "is malfunctional!\n", dev->base_addr );
                 return  -ENODEV;
         }
 }
 
 static void __init sbni_devsetup(struct net_device *dev)
 {
         ether_setup( dev );
         dev->open                = &sbni_open;
         dev->stop                = &sbni_close;
         dev->hard_start_xmit        = &sbni_start_xmit;
         dev->get_stats                = &sbni_get_stats;
         dev->set_multicast_list        = &set_multicast_list;
         dev->do_ioctl                = &sbni_ioctl;
 }
 
 int __init sbni_probe(int unit)
 {
         struct net_device *dev;
         static unsigned  version_printed __initdata = 0;
         int err;
 
         dev = alloc_netdev(sizeof(struct net_local), "sbni", sbni_devsetup);
         if (!dev)
                 return -ENOMEM;
 
         sprintf(dev->name, "sbni%d", unit);
         netdev_boot_setup_check(dev);
 
         err = sbni_init(dev);
         if (err) {
                 free_netdev(dev);
                 return err;
         }
 
         err = register_netdev(dev);
         if (err) {
                 release_region( dev->base_addr, SBNI_IO_EXTENT );
                 free_netdev(dev);
                 return err;
         }
         if( version_printed++ == 0 )
                 printk( KERN_INFO "%s", version );
         return 0;
 }
 
 static int __init sbni_init(struct net_device *dev)
 {
         int  i;
         if( dev->base_addr )
                 return  sbni_isa_probe( dev );
         /* otherwise we have to perform search our adapter */
 
         if( io[ num ] != -1 )
                 dev->base_addr        = io[ num ],
                 dev->irq        = irq[ num ];
         else if( scandone  ||  io[ 0 ] != -1 )
                 return  -ENODEV;
 
         /* if io[ num ] contains non-zero address, then that is on ISA bus */
         if( dev->base_addr )
                 return  sbni_isa_probe( dev );
 
         /* ...otherwise - scan PCI first */
         if( !skip_pci_probe  &&  !sbni_pci_probe( dev ) )
                 return  0;
 
         if( io[ num ] == -1 ) {
                 /* Auto-scan will be stopped when first ISA card were found */
                 scandone = 1;
                 if( num > 0 )
                         return  -ENODEV;
         }
 
         for( i = 0;  netcard_portlist[ i ];  ++i ) {
                 int  ioaddr = netcard_portlist[ i ];
                 if( request_region( ioaddr, SBNI_IO_EXTENT, dev->name )
                     &&  sbni_probe1( dev, ioaddr, 0 ))
                         return 0;
         }
 
         return  -ENODEV;
 }
 
 
 int __init
 sbni_pci_probe( struct net_device  *dev )
 {
         struct pci_dev  *pdev = NULL;
 
         while( (pdev = pci_get_class( PCI_CLASS_NETWORK_OTHER << 8, pdev ))
                != NULL ) {
                 int  pci_irq_line;
                 unsigned long  pci_ioaddr;
                 u16  subsys;
 
                 if( pdev->vendor != SBNI_PCI_VENDOR
                     &&  pdev->device != SBNI_PCI_DEVICE )
                                 continue;
 
                 pci_ioaddr = pci_resource_start( pdev, 0 );
                 pci_irq_line = pdev->irq;
 
                 /* Avoid already found cards from previous calls */
                 if( !request_region( pci_ioaddr, SBNI_IO_EXTENT, dev->name ) ) {
                         pci_read_config_word( pdev, PCI_SUBSYSTEM_ID, &subsys );
 
                         if (subsys != 2)
                                 continue;
 
                         /* Dual adapter is present */
                         if (!request_region(pci_ioaddr += 4, SBNI_IO_EXTENT,
                                                         dev->name ) )
                                 continue;
                 }
 
                 if (pci_irq_line <= 0 || pci_irq_line >= nr_irqs)
                         printk( KERN_WARNING "  WARNING: The PCI BIOS assigned "
                                 "this PCI card to IRQ %d, which is unlikely "
                                 "to work!.\n"
                                 KERN_WARNING " You should use the PCI BIOS "
                                 "setup to assign a valid IRQ line.\n",
                                 pci_irq_line );
 
                 /* avoiding re-enable dual adapters */
                 if( (pci_ioaddr & 7) == 0  &&  pci_enable_device( pdev ) ) {
                         release_region( pci_ioaddr, SBNI_IO_EXTENT );
                         pci_dev_put( pdev );
                         return  -EIO;
                 }
                 if( sbni_probe1( dev, pci_ioaddr, pci_irq_line ) ) {
                         SET_NETDEV_DEV(dev, &pdev->dev);
                         /* not the best thing to do, but this is all messed up 
                            for hotplug systems anyway... */
                         pci_dev_put( pdev );
                         return  0;
                 }
         }
         return  -ENODEV;
 }
 
 
 static struct net_device * __init
 sbni_probe1( struct net_device  *dev,  unsigned long  ioaddr,  int  irq )
 {
         struct net_local  *nl;
 
         if( sbni_card_probe( ioaddr ) ) {
                 release_region( ioaddr, SBNI_IO_EXTENT );
                 return NULL;
         }
 
         outb( 0, ioaddr + CSR0 );
 
         if( irq < 2 ) {
                 unsigned long irq_mask;
 
                 irq_mask = probe_irq_on();
                 outb( EN_INT | TR_REQ, ioaddr + CSR0 );
                 outb( PR_RES, ioaddr + CSR1 );
                 mdelay(50);
                 irq = probe_irq_off(irq_mask);
                 outb( 0, ioaddr + CSR0 );
 
                 if( !irq ) {
                         printk( KERN_ERR "%s: can't detect device irq!\n",
                                 dev->name );
                         release_region( ioaddr, SBNI_IO_EXTENT );
                         return NULL;
                 }
         } else if( irq == 2 )
                 irq = 9;
 
         dev->irq = irq;
         dev->base_addr = ioaddr;
 
         /* Allocate dev->priv and fill in sbni-specific dev fields. */
         nl = dev->priv;
         if( !nl ) {
                 printk( KERN_ERR "%s: unable to get memory!\n", dev->name );
                 release_region( ioaddr, SBNI_IO_EXTENT );
                 return NULL;
         }
 
         dev->priv = nl;
         memset( nl, 0, sizeof(struct net_local) );
         spin_lock_init( &nl->lock );
 
         /* store MAC address (generate if that isn't known) */
         *(__be16 *)dev->dev_addr = htons( 0x00ff );
         *(__be32 *)(dev->dev_addr + 2) = htonl( 0x01000000 |
                 ( (mac[num]  ?  mac[num]  :  (u32)((long)dev->priv)) & 0x00ffffff) );
 
         /* store link settings (speed, receive level ) */
         nl->maxframe  = DEFAULT_FRAME_LEN;
         nl->csr1.rate = baud[ num ];
 
         if( (nl->cur_rxl_index = rxl[ num ]) == -1 )
                 /* autotune rxl */
                 nl->cur_rxl_index = DEF_RXL,
                 nl->delta_rxl = DEF_RXL_DELTA;
         else
                 nl->delta_rxl = 0;
         nl->csr1.rxl  = rxl_tab[ nl->cur_rxl_index ];
         if( inb( ioaddr + CSR0 ) & 0x01 )
                 nl->state |= FL_SLOW_MODE;
 
         printk( KERN_NOTICE "%s: ioaddr %#lx, irq %d, "
                 "MAC: 00:ff:01:%02x:%02x:%02x\n", 
                 dev->name, dev->base_addr, dev->irq,
                 ((u8 *) dev->dev_addr) [3],
                 ((u8 *) dev->dev_addr) [4],
                 ((u8 *) dev->dev_addr) [5] );
 
         printk( KERN_NOTICE "%s: speed %d, receive level ", dev->name,
                 ( (nl->state & FL_SLOW_MODE)  ?  500000 : 2000000)
                 / (1 << nl->csr1.rate) );
 
         if( nl->delta_rxl == 0 )
                 printk( "0x%x (fixed)\n", nl->cur_rxl_index ); 
         else
                 printk( "(auto)\n");
 
 #ifdef CONFIG_SBNI_MULTILINE
         nl->master = dev;
         nl->link   = NULL;
 #endif
    
         sbni_cards[ num++ ] = dev;
         return  dev;
 }
 
 /* -------------------------------------------------------------------------- */
 
 #ifdef CONFIG_SBNI_MULTILINE
 
 static int
 sbni_start_xmit( struct sk_buff  *skb,  struct net_device  *dev )
 {
         struct net_device  *p;
 
         netif_stop_queue( dev );
 
         /* Looking for idle device in the list */
         for( p = dev;  p; ) {
                 struct net_local  *nl = (struct net_local *) p->priv;
                 spin_lock( &nl->lock );
                 if( nl->tx_buf_p  ||  (nl->state & FL_LINE_DOWN) ) {
                         p = nl->link;
                         spin_unlock( &nl->lock );
                 } else {
                         /* Idle dev is found */
                         prepare_to_send( skb, p );
                         spin_unlock( &nl->lock );
                         netif_start_queue( dev );
                         return  0;
                 }
         }
 
         return  1;
 }
 
 #else        /* CONFIG_SBNI_MULTILINE */
 
 static int
 sbni_start_xmit( struct sk_buff  *skb,  struct net_device  *dev )
 {
         struct net_local  *nl  = (struct net_local *) dev->priv;
 
         netif_stop_queue( dev );
         spin_lock( &nl->lock );
 
         prepare_to_send( skb, dev );
 
         spin_unlock( &nl->lock );
         return  0;
 }
 
 #endif        /* CONFIG_SBNI_MULTILINE */
 
 /* -------------------------------------------------------------------------- */
 
 /* interrupt handler */
 
 /*
  *         SBNI12D-10, -11/ISA boards within "common interrupt" mode could not
  * be looked as two independent single-channel devices. Every channel seems
  * as Ethernet interface but interrupt handler must be common. Really, first
  * channel ("master") driver only registers the handler. In its struct net_local
  * it has got pointer to "slave" channel's struct net_local and handles that's
  * interrupts too.
  *        dev of successfully attached ISA SBNI boards is linked to list.
  * While next board driver is initialized, it scans this list. If one
  * has found dev with same irq and ioaddr different by 4 then it assumes
  * this board to be "master".
  */ 
 
 static irqreturn_t
 sbni_interrupt( int  irq,  void  *dev_id )
 {
         struct net_device          *dev = dev_id;
         struct net_local  *nl  = dev->priv;
         int        repeat;
 
         spin_lock( &nl->lock );
         if( nl->second )
                 spin_lock( &((struct net_local *) nl->second->priv)->lock );
 
         do {
                 repeat = 0;
                 if( inb( dev->base_addr + CSR0 ) & (RC_RDY | TR_RDY) )
                         handle_channel( dev ),
                         repeat = 1;
                 if( nl->second  &&         /* second channel present */
                     (inb( nl->second->base_addr+CSR0 ) & (RC_RDY | TR_RDY)) )
                         handle_channel( nl->second ),
                         repeat = 1;
         } while( repeat );
 
         if( nl->second )
                 spin_unlock( &((struct net_local *)nl->second->priv)->lock );
         spin_unlock( &nl->lock );
         return IRQ_HANDLED;
 }
 
 
 static void
 handle_channel( struct net_device  *dev )
 {
         struct net_local        *nl    = (struct net_local *) dev->priv;
         unsigned long                ioaddr = dev->base_addr;
 
         int  req_ans;
         unsigned char  csr0;
 
 #ifdef CONFIG_SBNI_MULTILINE
         /* Lock the master device because we going to change its local data */
         if( nl->state & FL_SLAVE )
                 spin_lock( &((struct net_local *) nl->master->priv)->lock );
 #endif
 
         outb( (inb( ioaddr + CSR0 ) & ~EN_INT) | TR_REQ, ioaddr + CSR0 );
 
         nl->timer_ticks = CHANGE_LEVEL_START_TICKS;
         for(;;) {
                 csr0 = inb( ioaddr + CSR0 );
                 if( ( csr0 & (RC_RDY | TR_RDY) ) == 0 )
                         break;
 
                 req_ans = !(nl->state & FL_PREV_OK);
 
                 if( csr0 & RC_RDY )
                         req_ans = recv_frame( dev );
 
                 /*
                  * TR_RDY always equals 1 here because we have owned the marker,
                  * and we set TR_REQ when disabled interrupts
                  */
                 csr0 = inb( ioaddr + CSR0 );
                 if( !(csr0 & TR_RDY)  ||  (csr0 & RC_RDY) )
                         printk( KERN_ERR "%s: internal error!\n", dev->name );
 
                 /* if state & FL_NEED_RESEND != 0 then tx_frameno != 0 */
                 if( req_ans  ||  nl->tx_frameno != 0 )
                         send_frame( dev );
                 else
                         /* send marker without any data */
                         outb( inb( ioaddr + CSR0 ) & ~TR_REQ, ioaddr + CSR0 );
         }
 
         outb( inb( ioaddr + CSR0 ) | EN_INT, ioaddr + CSR0 );
 
 #ifdef CONFIG_SBNI_MULTILINE
         if( nl->state & FL_SLAVE )
                 spin_unlock( &((struct net_local *) nl->master->priv)->lock );
 #endif
 }
 
 
 /*
  * Routine returns 1 if it need to acknoweledge received frame.
  * Empty frame received without errors won't be acknoweledged.
  */
 
 static int
 recv_frame( struct net_device  *dev )
 {
         struct net_local  *nl   = (struct net_local *) dev->priv;
         unsigned long  ioaddr        = dev->base_addr;
 
         u32  crc = CRC32_INITIAL;
 
         unsigned  framelen = 0, frameno, ack;
         unsigned  is_first, frame_ok = 0;
 
         if( check_fhdr( ioaddr, &framelen, &frameno, &ack, &is_first, &crc ) ) {
                 frame_ok = framelen > 4
                         ?  upload_data( dev, framelen, frameno, is_first, crc )
                         :  skip_tail( ioaddr, framelen, crc );
                 if( frame_ok )
                         interpret_ack( dev, ack );
         }
 
         outb( inb( ioaddr + CSR0 ) ^ CT_ZER, ioaddr + CSR0 );
         if( frame_ok ) {
                 nl->state |= FL_PREV_OK;
                 if( framelen > 4 )
                         nl->in_stats.all_rx_number++;
         } else
                 nl->state &= ~FL_PREV_OK,
                 change_level( dev ),
                 nl->in_stats.all_rx_number++,
                 nl->in_stats.bad_rx_number++;
 
         return  !frame_ok  ||  framelen > 4;
 }
 
 
 static void
 send_frame( struct net_device  *dev )
 {
         struct net_local  *nl    = (struct net_local *) dev->priv;
 
         u32  crc = CRC32_INITIAL;
 
         if( nl->state & FL_NEED_RESEND ) {
 
                 /* if frame was sended but not ACK'ed - resend it */
                 if( nl->trans_errors ) {
                         --nl->trans_errors;
                         if( nl->framelen != 0 )
                                 nl->in_stats.resend_tx_number++;
                 } else {
                         /* cannot xmit with many attempts */
 #ifdef CONFIG_SBNI_MULTILINE
                         if( (nl->state & FL_SLAVE)  ||  nl->link )
 #endif
                         nl->state |= FL_LINE_DOWN;
                         drop_xmit_queue( dev );
                         goto  do_send;
                 }
         } else
                 nl->trans_errors = TR_ERROR_COUNT;
 
         send_frame_header( dev, &crc );
         nl->state |= FL_NEED_RESEND;
         /*
          * FL_NEED_RESEND will be cleared after ACK, but if empty
          * frame sended then in prepare_to_send next frame
          */
 
 
         if( nl->framelen ) {
                 download_data( dev, &crc );
                 nl->in_stats.all_tx_number++;
                 nl->state |= FL_WAIT_ACK;
         }
 
         outsb( dev->base_addr + DAT, (u8 *)&crc, sizeof crc );
 
 do_send:
         outb( inb( dev->base_addr + CSR0 ) & ~TR_REQ, dev->base_addr + CSR0 );
 
         if( nl->tx_frameno )
                 /* next frame exists - we request card to send it */
                 outb( inb( dev->base_addr + CSR0 ) | TR_REQ,
                       dev->base_addr + CSR0 );
 }
 
 
 /*
  * Write the frame data into adapter's buffer memory, and calculate CRC.
  * Do padding if necessary.
  */
 
 static void
 download_data( struct net_device  *dev,  u32  *crc_p )
 {
         struct net_local  *nl    = (struct net_local *) dev->priv;
         struct sk_buff    *skb         = nl->tx_buf_p;
 
         unsigned  len = min_t(unsigned int, skb->len - nl->outpos, nl->framelen);
 
         outsb( dev->base_addr + DAT, skb->data + nl->outpos, len );
         *crc_p = calc_crc32( *crc_p, skb->data + nl->outpos, len );
 
         /* if packet too short we should write some more bytes to pad */
         for( len = nl->framelen - len;  len--; )
                 outb( 0, dev->base_addr + DAT ),
                 *crc_p = CRC32( 0, *crc_p );
 }
 
 
 static int
 upload_data( struct net_device  *dev,  unsigned  framelen,  unsigned  frameno,
              unsigned  is_first,  u32  crc )
 {
         struct net_local  *nl = (struct net_local *) dev->priv;
 
         int  frame_ok;
 
         if( is_first )
                 nl->wait_frameno = frameno,
                 nl->inppos = 0;
 
         if( nl->wait_frameno == frameno ) {
 
                 if( nl->inppos + framelen  <=  ETHER_MAX_LEN )
                         frame_ok = append_frame_to_pkt( dev, framelen, crc );
 
                 /*
                  * if CRC is right but framelen incorrect then transmitter
                  * error was occurred... drop entire packet
                  */
                 else if( (frame_ok = skip_tail( dev->base_addr, framelen, crc ))
                          != 0 )
                         nl->wait_frameno = 0,
                         nl->inppos = 0,
 #ifdef CONFIG_SBNI_MULTILINE
                         ((struct net_local *) nl->master->priv)
                                 ->stats.rx_errors++,
                         ((struct net_local *) nl->master->priv)
                                 ->stats.rx_missed_errors++;
 #else
                         nl->stats.rx_errors++,
                         nl->stats.rx_missed_errors++;
 #endif
                         /* now skip all frames until is_first != 0 */
         } else
                 frame_ok = skip_tail( dev->base_addr, framelen, crc );
 
         if( is_first  &&  !frame_ok )
                 /*
                  * Frame has been broken, but we had already stored
                  * is_first... Drop entire packet.
                  */
                 nl->wait_frameno = 0,
 #ifdef CONFIG_SBNI_MULTILINE
                 ((struct net_local *) nl->master->priv)->stats.rx_errors++,
                 ((struct net_local *) nl->master->priv)->stats.rx_crc_errors++;
 #else
                 nl->stats.rx_errors++,
                 nl->stats.rx_crc_errors++;
 #endif
 
         return  frame_ok;
 }
 
 
 static inline void
 send_complete( struct net_local  *nl )
 {
 #ifdef CONFIG_SBNI_MULTILINE
         ((struct net_local *) nl->master->priv)->stats.tx_packets++;
         ((struct net_local *) nl->master->priv)->stats.tx_bytes
                 += nl->tx_buf_p->len;
 #else
         nl->stats.tx_packets++;
         nl->stats.tx_bytes += nl->tx_buf_p->len;
 #endif
         dev_kfree_skb_irq( nl->tx_buf_p );
 
         nl->tx_buf_p = NULL;
 
         nl->outpos = 0;
         nl->state &= ~(FL_WAIT_ACK | FL_NEED_RESEND);
         nl->framelen   = 0;
 }
 
 
 static void
 interpret_ack( struct net_device  *dev,  unsigned  ack )
 {
         struct net_local  *nl = (struct net_local *) dev->priv;
 
         if( ack == FRAME_SENT_OK ) {
                 nl->state &= ~FL_NEED_RESEND;
 
                 if( nl->state & FL_WAIT_ACK ) {
                         nl->outpos += nl->framelen;
 
                         if( --nl->tx_frameno )
                                 nl->framelen = min_t(unsigned int,
                                                    nl->maxframe,
                                                    nl->tx_buf_p->len - nl->outpos);
                         else
                                 send_complete( nl ),
 #ifdef CONFIG_SBNI_MULTILINE
                                 netif_wake_queue( nl->master );
 #else
                                 netif_wake_queue( dev );
 #endif
                 }
         }
 
         nl->state &= ~FL_WAIT_ACK;
 }
 
 
 /*
  * Glue received frame with previous fragments of packet.
  * Indicate packet when last frame would be accepted.
  */
 
 static int
 append_frame_to_pkt( struct net_device  *dev,  unsigned  framelen,  u32  crc )
 {
         struct net_local  *nl = (struct net_local *) dev->priv;
 
         u8  *p;
 
         if( nl->inppos + framelen  >  ETHER_MAX_LEN )
                 return  0;
 
         if( !nl->rx_buf_p  &&  !(nl->rx_buf_p = get_rx_buf( dev )) )
                 return  0;
 
         p = nl->rx_buf_p->data + nl->inppos;
         insb( dev->base_addr + DAT, p, framelen );
         if( calc_crc32( crc, p, framelen ) != CRC32_REMAINDER )
                 return  0;
 
         nl->inppos += framelen - 4;
         if( --nl->wait_frameno == 0 )                /* last frame received */
                 indicate_pkt( dev );
 
         return  1;
 }
 
 
 /*
  * Prepare to start output on adapter.
  * Transmitter will be actually activated when marker is accepted.
  */
 
 static void
 prepare_to_send( struct sk_buff  *skb,  struct net_device  *dev )
 {
         struct net_local  *nl = (struct net_local *) dev->priv;
 
         unsigned int  len;
 
         /* nl->tx_buf_p == NULL here! */
         if( nl->tx_buf_p )
                 printk( KERN_ERR "%s: memory leak!\n", dev->name );
 
         nl->outpos = 0;
         nl->state &= ~(FL_WAIT_ACK | FL_NEED_RESEND);
 
         len = skb->len;
         if( len < SBNI_MIN_LEN )
                 len = SBNI_MIN_LEN;
 
         nl->tx_buf_p        = skb;
         nl->tx_frameno        = DIV_ROUND_UP(len, nl->maxframe);
         nl->framelen        = len < nl->maxframe  ?  len  :  nl->maxframe;
 
         outb( inb( dev->base_addr + CSR0 ) | TR_REQ,  dev->base_addr + CSR0 );
 #ifdef CONFIG_SBNI_MULTILINE
         nl->master->trans_start = jiffies;
 #else
         dev->trans_start = jiffies;
 #endif
 }
 
 
 static void
 drop_xmit_queue( struct net_device  *dev )
 {
         struct net_local  *nl = (struct net_local *) dev->priv;
 
         if( nl->tx_buf_p )
                 dev_kfree_skb_any( nl->tx_buf_p ),
                 nl->tx_buf_p = NULL,
 #ifdef CONFIG_SBNI_MULTILINE
                 ((struct net_local *) nl->master->priv)
                         ->stats.tx_errors++,
                 ((struct net_local *) nl->master->priv)
                         ->stats.tx_carrier_errors++;
 #else
                 nl->stats.tx_errors++,
                 nl->stats.tx_carrier_errors++;
 #endif
 
         nl->tx_frameno        = 0;
         nl->framelen        = 0;
         nl->outpos        = 0;
         nl->state &= ~(FL_WAIT_ACK | FL_NEED_RESEND);
 #ifdef CONFIG_SBNI_MULTILINE
         netif_start_queue( nl->master );
         nl->master->trans_start = jiffies;
 #else
         netif_start_queue( dev );
         dev->trans_start = jiffies;
 #endif
 }
 
 
 static void
 send_frame_header( struct net_device  *dev,  u32  *crc_p )
 {
         struct net_local  *nl  = (struct net_local *) dev->priv;
 
         u32  crc = *crc_p;
         u32  len_field = nl->framelen + 6;        /* CRC + frameno + reserved */
         u8   value;
 
         if( nl->state & FL_NEED_RESEND )
                 len_field |= FRAME_RETRY;        /* non-first attempt... */
 
         if( nl->outpos == 0 )
                 len_field |= FRAME_FIRST;
 
         len_field |= (nl->state & FL_PREV_OK) ? FRAME_SENT_OK : FRAME_SENT_BAD;
         outb( SBNI_SIG, dev->base_addr + DAT );
 
         value = (u8) len_field;
         outb( value, dev->base_addr + DAT );
         crc = CRC32( value, crc );
         value = (u8) (len_field >> 8);
         outb( value, dev->base_addr + DAT );
         crc = CRC32( value, crc );
 
         outb( nl->tx_frameno, dev->base_addr + DAT );
         crc = CRC32( nl->tx_frameno, crc );
         outb( 0, dev->base_addr + DAT );
         crc = CRC32( 0, crc );
         *crc_p = crc;
 }
 
 
 /*
  * if frame tail not needed (incorrect number or received twice),
  * it won't store, but CRC will be calculated
  */
 
 static int
 skip_tail( unsigned int  ioaddr,  unsigned int  tail_len,  u32 crc )
 {
         while( tail_len-- )
                 crc = CRC32( inb( ioaddr + DAT ), crc );
 
         return  crc == CRC32_REMAINDER;
 }
 
 
 /*
  * Preliminary checks if frame header is correct, calculates its CRC
  * and split it to simple fields
  */
 
 static int
 check_fhdr( u32  ioaddr,  u32  *framelen,  u32  *frameno,  u32  *ack,
             u32  *is_first,  u32  *crc_p )
 {
         u32  crc = *crc_p;
         u8   value;
 
         if( inb( ioaddr + DAT ) != SBNI_SIG )
                 return  0;
 
         value = inb( ioaddr + DAT );
         *framelen = (u32)value;
         crc = CRC32( value, crc );
         value = inb( ioaddr + DAT );
         *framelen |= ((u32)value) << 8;
         crc = CRC32( value, crc );
 
         *ack = *framelen & FRAME_ACK_MASK;
         *is_first = (*framelen & FRAME_FIRST) != 0;
 
         if( (*framelen &= FRAME_LEN_MASK) < 6
             ||  *framelen > SBNI_MAX_FRAME - 3 )
                 return  0;
 
         value = inb( ioaddr + DAT );
         *frameno = (u32)value;
         crc = CRC32( value, crc );
 
         crc = CRC32( inb( ioaddr + DAT ), crc );        /* reserved byte */
         *framelen -= 2;
 
         *crc_p = crc;
         return  1;
 }
 
 
 static struct sk_buff *
 get_rx_buf( struct net_device  *dev )
 {
         /* +2 is to compensate for the alignment fixup below */
         struct sk_buff  *skb = dev_alloc_skb( ETHER_MAX_LEN + 2 );
         if( !skb )
                 return  NULL;
 
        skb_reserve( skb, 2 );                /* Align IP on longword boundaries */
        return  skb;
}


static void
indicate_pkt( struct net_device  *dev )
{
        struct net_local  *nl  = (struct net_local *) dev->priv;
        struct sk_buff    *skb = nl->rx_buf_p;

        skb_put( skb, nl->inppos );

#ifdef CONFIG_SBNI_MULTILINE
        skb->protocol = eth_type_trans( skb, nl->master );
        netif_rx( skb );
        dev->last_rx = jiffies;
        ++((struct net_local *) nl->master->priv)->stats.rx_packets;
        ((struct net_local *) nl->master->priv)->stats.rx_bytes += nl->inppos;
#else
        skb->protocol = eth_type_trans( skb, dev );
        netif_rx( skb );
        dev->last_rx = jiffies;
        ++nl->stats.rx_packets;
        nl->stats.rx_bytes += nl->inppos;
#endif
        nl->rx_buf_p = NULL;        /* protocol driver will clear this sk_buff */
}


/* -------------------------------------------------------------------------- */

/*
 * Routine checks periodically wire activity and regenerates marker if
 * connect was inactive for a long time.
 */

static void
sbni_watchdog( unsigned long  arg )
{
        struct net_device  *dev = (struct net_device *) arg;
        struct net_local   *nl  = (struct net_local *) dev->priv;
        struct timer_list  *w   = &nl->watchdog; 
        unsigned long           flags;
        unsigned char           csr0;

        spin_lock_irqsave( &nl->lock, flags );

        csr0 = inb( dev->base_addr + CSR0 );
        if( csr0 & RC_CHK ) {

                if( nl->timer_ticks ) {
                        if( csr0 & (RC_RDY | BU_EMP) )
                                /* receiving not active */
                                nl->timer_ticks--;
                } else {
                        nl->in_stats.timeout_number++;
                        if( nl->delta_rxl )
                                timeout_change_level( dev );

                        outb( *(u_char *)&nl->csr1 | PR_RES,
                              dev->base_addr + CSR1 );
                        csr0 = inb( dev->base_addr + CSR0 );
                }
        } else
                nl->state &= ~FL_LINE_DOWN;

        outb( csr0 | RC_CHK, dev->base_addr + CSR0 ); 

        init_timer( w );
        w->expires        = jiffies + SBNI_TIMEOUT;
        w->data                = arg;
        w->function        = sbni_watchdog;
        add_timer( w );

        spin_unlock_irqrestore( &nl->lock, flags );
}


static unsigned char  rxl_tab[] = {
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x08,
        0x0a, 0x0c, 0x0f, 0x16, 0x18, 0x1a, 0x1c, 0x1f
};

#define SIZE_OF_TIMEOUT_RXL_TAB 4
static unsigned char  timeout_rxl_tab[] = {
        0x03, 0x05, 0x08, 0x0b
};

/* -------------------------------------------------------------------------- */

static void
card_start( struct net_device  *dev )
{
        struct net_local  *nl = (struct net_local *) dev->priv;

        nl->timer_ticks = CHANGE_LEVEL_START_TICKS;
        nl->state &= ~(FL_WAIT_ACK | FL_NEED_RESEND);
        nl->state |= FL_PREV_OK;

        nl->inppos = nl->outpos = 0;
        nl->wait_frameno = 0;
        nl->tx_frameno         = 0;
        nl->framelen         = 0;

        outb( *(u_char *)&nl->csr1 | PR_RES, dev->base_addr + CSR1 );
        outb( EN_INT, dev->base_addr + CSR0 );
}

/* -------------------------------------------------------------------------- */

/* Receive level auto-selection */

static void
change_level( struct net_device  *dev )
{
        struct net_local  *nl = (struct net_local *) dev->priv;

        if( nl->delta_rxl == 0 )        /* do not auto-negotiate RxL */
                return;

        if( nl->cur_rxl_index == 0 )
                nl->delta_rxl = 1;
        else if( nl->cur_rxl_index == 15 )
                nl->delta_rxl = -1;
        else if( nl->cur_rxl_rcvd < nl->prev_rxl_rcvd )
                nl->delta_rxl = -nl->delta_rxl;

        nl->csr1.rxl = rxl_tab[ nl->cur_rxl_index += nl->delta_rxl ];
        inb( dev->base_addr + CSR0 );        /* needs for PCI cards */
        outb( *(u8 *)&nl->csr1, dev->base_addr + CSR1 );

        nl->prev_rxl_rcvd = nl->cur_rxl_rcvd;
        nl->cur_rxl_rcvd  = 0;
}


static void
timeout_change_level( struct net_device  *dev )
{
        struct net_local  *nl = (struct net_local *) dev->priv;

        nl->cur_rxl_index = timeout_rxl_tab[ nl->timeout_rxl ];
        if( ++nl->timeout_rxl >= 4 )
                nl->timeout_rxl = 0;

        nl->csr1.rxl = rxl_tab[ nl->cur_rxl_index ];
        inb( dev->base_addr + CSR0 );
        outb( *(unsigned char *)&nl->csr1, dev->base_addr + CSR1 );

        nl->prev_rxl_rcvd = nl->cur_rxl_rcvd;
        nl->cur_rxl_rcvd  = 0;
}

/* -------------------------------------------------------------------------- */

/*
 *        Open/initialize the board. 
 */

static int
sbni_open( struct net_device  *dev )
{
        struct net_local        *nl = (struct net_local *) dev->priv;
        struct timer_list        *w  = &nl->watchdog;

        /*
         * For double ISA adapters within "common irq" mode, we have to
         * determine whether primary or secondary channel is initialized,
         * and set the irq handler only in first case.
         */
        if( dev->base_addr < 0x400 ) {                /* ISA only */
                struct net_device  **p = sbni_cards;
                for( ;  *p  &&  p < sbni_cards + SBNI_MAX_NUM_CARDS;  ++p )
                        if( (*p)->irq == dev->irq
                            &&  ((*p)->base_addr == dev->base_addr + 4
                                 ||  (*p)->base_addr == dev->base_addr - 4)
                            &&  (*p)->flags & IFF_UP ) {

                                ((struct net_local *) ((*p)->priv))
                                        ->second = dev;
                                printk( KERN_NOTICE "%s: using shared irq "
                                        "with %s\n", dev->name, (*p)->name );
                                nl->state |= FL_SECONDARY;
                                goto  handler_attached;
                        }
        }

        if( request_irq(dev->irq, sbni_interrupt, IRQF_SHARED, dev->name, dev) ) {
                printk( KERN_ERR "%s: unable to get IRQ %d.\n",
                        dev->name, dev->irq );
                return  -EAGAIN;
        }

handler_attached:

        spin_lock( &nl->lock );
        memset( &nl->stats, 0, sizeof(struct net_device_stats) );
        memset( &nl->in_stats, 0, sizeof(struct sbni_in_stats) );

        card_start( dev );

        netif_start_queue( dev );

        /* set timer watchdog */
        init_timer( w );
        w->expires        = jiffies + SBNI_TIMEOUT;
        w->data                = (unsigned long) dev;
        w->function        = sbni_watchdog;
        add_timer( w );
   
        spin_unlock( &nl->lock );
        return 0;
}


static int
sbni_close( struct net_device  *dev )
{
        struct net_local  *nl = (struct net_local *) dev->priv;

        if( nl->second  &&  nl->second->flags & IFF_UP ) {
                printk( KERN_NOTICE "Secondary channel (%s) is active!\n",
                        nl->second->name );
                return  -EBUSY;
        }

#ifdef CONFIG_SBNI_MULTILINE
        if( nl->state & FL_SLAVE )
                emancipate( dev );
        else
                while( nl->link )        /* it's master device! */
                        emancipate( nl->link );
#endif

        spin_lock( &nl->lock );

        nl->second = NULL;
        drop_xmit_queue( dev );        
        netif_stop_queue( dev );
   
        del_timer( &nl->watchdog );

        outb( 0, dev->base_addr + CSR0 );

        if( !(nl->state & FL_SECONDARY) )
                free_irq( dev->irq, dev );
        nl->state &= FL_SECONDARY;

        spin_unlock( &nl->lock );
        return 0;
}


/*
        Valid combinations in CSR0 (for probing):

        VALID_DECODER        0000,0011,1011,1010

                                            ; 0   ; -
                                TR_REQ        ; 1   ; +
                        TR_RDY                    ; 2   ; -
                        TR_RDY        TR_REQ        ; 3   ; +
                BU_EMP                            ; 4   ; +
                BU_EMP                     TR_REQ        ; 5   ; +
                BU_EMP        TR_RDY                    ; 6   ; -
                BU_EMP        TR_RDY        TR_REQ        ; 7   ; +
        RC_RDY                                      ; 8   ; +
        RC_RDY                        TR_REQ        ; 9   ; +
        RC_RDY                TR_RDY                ; 10  ; -
        RC_RDY                TR_RDY        TR_REQ        ; 11  ; -
        RC_RDY        BU_EMP                        ; 12  ; -
        RC_RDY        BU_EMP                TR_REQ        ; 13  ; -
        RC_RDY        BU_EMP        TR_RDY                ; 14  ; -
        RC_RDY        BU_EMP        TR_RDY        TR_REQ        ; 15  ; -
*/

#define VALID_DECODER (2 + 8 + 0x10 + 0x20 + 0x80 + 0x100 + 0x200)


static int
sbni_card_probe( unsigned long  ioaddr )
{
        unsigned char  csr0;

        csr0 = inb( ioaddr + CSR0 );
        if( csr0 != 0xff  &&  csr0 != 0x00 ) {
                csr0 &= ~EN_INT;
                if( csr0 & BU_EMP )
                        csr0 |= EN_INT;
      
                if( VALID_DECODER & (1 << (csr0 >> 4)) )
                        return  0;
        }
   
        return  -ENODEV;
}

/* -------------------------------------------------------------------------- */

static int
sbni_ioctl( struct net_device  *dev,  struct ifreq  *ifr,  int  cmd )
{
        struct net_local  *nl = (struct net_local *) dev->priv; 
        struct sbni_flags  flags;
        int  error = 0;

#ifdef CONFIG_SBNI_MULTILINE
        struct net_device  *slave_dev;
        char  slave_name[ 8 ];
#endif
  
        switch( cmd ) {
        case  SIOCDEVGETINSTATS :
                if (copy_to_user( ifr->ifr_data, &nl->in_stats,
                                        sizeof(struct sbni_in_stats) ))
                        error = -EFAULT;
                break;

        case  SIOCDEVRESINSTATS :
                if (!capable(CAP_NET_ADMIN))
                        return  -EPERM;
                memset( &nl->in_stats, 0, sizeof(struct sbni_in_stats) );
                break;

        case  SIOCDEVGHWSTATE :
                flags.mac_addr        = *(u32 *)(dev->dev_addr + 3);
                flags.rate        = nl->csr1.rate;
                flags.slow_mode        = (nl->state & FL_SLOW_MODE) != 0;
                flags.rxl        = nl->cur_rxl_index;
                flags.fixed_rxl        = nl->delta_rxl == 0;

                if (copy_to_user( ifr->ifr_data, &flags, sizeof flags ))
                        error = -EFAULT;
                break;

        case  SIOCDEVSHWSTATE :
                if (!capable(CAP_NET_ADMIN))
                        return  -EPERM;

                spin_lock( &nl->lock );
                flags = *(struct sbni_flags*) &ifr->ifr_ifru;
                if( flags.fixed_rxl )
                        nl->delta_rxl = 0,
                        nl->cur_rxl_index = flags.rxl;
                else
                        nl->delta_rxl = DEF_RXL_DELTA,
                        nl->cur_rxl_index = DEF_RXL;

                nl->csr1.rxl = rxl_tab[ nl->cur_rxl_index ];
                nl->csr1.rate = flags.rate;
                outb( *(u8 *)&nl->csr1 | PR_RES, dev->base_addr + CSR1 );
                spin_unlock( &nl->lock );
                break;

#ifdef CONFIG_SBNI_MULTILINE

        case  SIOCDEVENSLAVE :
                if (!capable(CAP_NET_ADMIN))
                        return  -EPERM;

                if (copy_from_user( slave_name, ifr->ifr_data, sizeof slave_name ))
                        return -EFAULT;
                slave_dev = dev_get_by_name(&init_net, slave_name );
                if( !slave_dev  ||  !(slave_dev->flags & IFF_UP) ) {
                        printk( KERN_ERR "%s: trying to enslave non-active "
                                "device %s\n", dev->name, slave_name );
                        return  -EPERM;
                }

                return  enslave( dev, slave_dev );

        case  SIOCDEVEMANSIPATE :
                if (!capable(CAP_NET_ADMIN))
                        return  -EPERM;

                return  emancipate( dev );

#endif        /* CONFIG_SBNI_MULTILINE */

        default :
                return  -EOPNOTSUPP;
        }

        return  error;
}


#ifdef CONFIG_SBNI_MULTILINE

static int
enslave( struct net_device  *dev,  struct net_device  *slave_dev )
{
        struct net_local  *nl  = (struct net_local *) dev->priv;
        struct net_local  *snl = (struct net_local *) slave_dev->priv;

        if( nl->state & FL_SLAVE )        /* This isn't master or free device */
                return  -EBUSY;

        if( snl->state & FL_SLAVE )        /* That was already enslaved */
                return  -EBUSY;

        spin_lock( &nl->lock );
        spin_lock( &snl->lock );

        /* append to list */
        snl->link = nl->link;
        nl->link  = slave_dev;
        snl->master = dev;
        snl->state |= FL_SLAVE;

        /* Summary statistics of MultiLine operation will be stored
           in master's counters */
        memset( &snl->stats, 0, sizeof(struct net_device_stats) );
        netif_stop_queue( slave_dev );
        netif_wake_queue( dev );        /* Now we are able to transmit */

        spin_unlock( &snl->lock );
        spin_unlock( &nl->lock );
        printk( KERN_NOTICE "%s: slave device (%s) attached.\n",
                dev->name, slave_dev->name );
        return  0;
}


static int
emancipate( struct net_device  *dev )
{
        struct net_local   *snl = (struct net_local *) dev->priv;
        struct net_device  *p   = snl->master;
        struct net_local   *nl  = (struct net_local *) p->priv;

        if( !(snl->state & FL_SLAVE) )
                return  -EINVAL;

        spin_lock( &nl->lock );
        spin_lock( &snl->lock );
        drop_xmit_queue( dev );

        /* exclude from list */
        for(;;) {        /* must be in list */
                struct net_local  *t = (struct net_local *) p->priv;
                if( t->link == dev ) {
                        t->link = snl->link;
                        break;
                }
                p = t->link;
        }

        snl->link = NULL;
        snl->master = dev;
        snl->state &= ~FL_SLAVE;

        netif_start_queue( dev );

        spin_unlock( &snl->lock );
        spin_unlock( &nl->lock );

        dev_put( dev );
        return  0;
}

#endif


static struct net_device_stats *
sbni_get_stats( struct net_device  *dev )
{
        return  &((struct net_local *) dev->priv)->stats;
}


static void
set_multicast_list( struct net_device  *dev )
{
        return;                /* sbni always operate in promiscuos mode */
}


#ifdef MODULE
module_param_array(io, int, NULL, 0);
module_param_array(irq, int, NULL, 0);
module_param_array(baud, int, NULL, 0);
module_param_array(rxl, int, NULL, 0);
module_param_array(mac, int, NULL, 0);
module_param(skip_pci_probe, bool, 0);

MODULE_LICENSE("GPL");


int __init init_module( void )
{
        struct net_device  *dev;
        int err;

        while( num < SBNI_MAX_NUM_CARDS ) {
                dev = alloc_netdev(sizeof(struct net_local), 
                                   "sbni%d", sbni_devsetup);
                if( !dev)
                        break;

                sprintf( dev->name, "sbni%d", num );

                err = sbni_init(dev);
                if (err) {
                        free_netdev(dev);
                        break;
                }

                if( register_netdev( dev ) ) {
                        release_region( dev->base_addr, SBNI_IO_EXTENT );
                        free_netdev( dev );
                        break;
                }
        }

        return  *sbni_cards  ?  0  :  -ENODEV;
}

void
cleanup_module( void )
{
        struct net_device  *dev;
        int  num;

        for( num = 0;  num < SBNI_MAX_NUM_CARDS;  ++num )
                if( (dev = sbni_cards[ num ]) != NULL ) {
                        unregister_netdev( dev );
                        release_region( dev->base_addr, SBNI_IO_EXTENT );
                        free_netdev( dev );
                }
}

#else        /* MODULE */

static int __init
sbni_setup( char  *p )
{
        int  n, parm;

        if( *p++ != '(' )
                goto  bad_param;

        for( n = 0, parm = 0;  *p  &&  n < 8; ) {
                (*dest[ parm ])[ n ] = simple_strtol( p, &p, 0 );
                if( !*p  ||  *p == ')' )
                        return 1;
                if( *p == ';' )
                        ++p, ++n, parm = 0;
                else if( *p++ != ',' )
                        break;
                else
                        if( ++parm >= 5 )
                                break;
        }
bad_param:
        printk( KERN_ERR "Error in sbni kernel parameter!\n" );
        return 0;
}

__setup( "sbni=", sbni_setup );

#endif        /* MODULE */

/* -------------------------------------------------------------------------- */

#ifdef ASM_CRC

static u32
calc_crc32( u32  crc,  u8  *p,  u32  len )
{
        register u32  _crc;
        _crc = crc;
        
        __asm__ __volatile__ (
                "xorl        %%ebx, %%ebx\n"
                "movl        %2, %%esi\n" 
                "movl        %3, %%ecx\n" 
                "movl        $crc32tab, %%edi\n"
                "shrl        $2, %%ecx\n"
                "jz        1f\n"

                ".align 4\n"
        "0:\n"
                "movb        %%al, %%bl\n"
                "movl        (%%esi), %%edx\n"
                "shrl        $8, %%eax\n"
                "xorb        %%dl, %%bl\n"
                "shrl        $8, %%edx\n"
                "xorl        (%%edi,%%ebx,4), %%eax\n"

                "movb        %%al, %%bl\n"
                "shrl        $8, %%eax\n"
                "xorb        %%dl, %%bl\n"
                "shrl        $8, %%edx\n"
                "xorl        (%%edi,%%ebx,4), %%eax\n"

                "movb        %%al, %%bl\n"
                "shrl        $8, %%eax\n"
                "xorb        %%dl, %%bl\n"
                "movb        %%dh, %%dl\n" 
                "xorl        (%%edi,%%ebx,4), %%eax\n"

                "movb        %%al, %%bl\n"
                "shrl        $8, %%eax\n"
                "xorb        %%dl, %%bl\n"
                "addl        $4, %%esi\n"
                "xorl        (%%edi,%%ebx,4), %%eax\n"

                "decl        %%ecx\n"
                "jnz        0b\n"

        "1:\n"
                "movl        %3, %%ecx\n"
                "andl        $3, %%ecx\n"
                "jz        2f\n"

                "movb        %%al, %%bl\n"
                "shrl        $8, %%eax\n"
                "xorb        (%%esi), %%bl\n"
                "xorl        (%%edi,%%ebx,4), %%eax\n"

                "decl        %%ecx\n"
                "jz        2f\n"

                "movb        %%al, %%bl\n"
                "shrl        $8, %%eax\n"
                "xorb        1(%%esi), %%bl\n"
                "xorl        (%%edi,%%ebx,4), %%eax\n"

                "decl        %%ecx\n"
                "jz        2f\n"

                "movb        %%al, %%bl\n"
                "shrl        $8, %%eax\n"
                "xorb        2(%%esi), %%bl\n"
                "xorl        (%%edi,%%ebx,4), %%eax\n"
        "2:\n"
                : "=a" (_crc)
                : "0" (_crc), "g" (p), "g" (len)
                : "bx", "cx", "dx", "si", "di"
        );

        return  _crc;
}

#else        /* ASM_CRC */

static u32
calc_crc32( u32  crc,  u8  *p,  u32  len )
{
        while( len-- )
                crc = CRC32( *p++, crc );

        return  crc;
}

#endif        /* ASM_CRC */


static u32  crc32tab[] __attribute__ ((aligned(8))) = {
        0xD202EF8D,  0xA505DF1B,  0x3C0C8EA1,  0x4B0BBE37,
        0xD56F2B94,  0xA2681B02,  0x3B614AB8,  0x4C667A2E,
        0xDCD967BF,  0xABDE5729,  0x32D70693,  0x45D03605,
        0xDBB4A3A6,  0xACB39330,  0x35BAC28A,  0x42BDF21C,
        0xCFB5FFE9,  0xB8B2CF7F,  0x21BB9EC5,  0x56BCAE53,
        0xC8D83BF0,  0xBFDF0B66,  0x26D65ADC,  0x51D16A4A,
        0xC16E77DB,  0xB669474D,  0x2F6016F7,  0x58672661,
        0xC603B3C2,  0xB1048354,  0x280DD2EE,  0x5F0AE278,
        0xE96CCF45,  0x9E6BFFD3,  0x0762AE69,  0x70659EFF,
        0xEE010B5C,  0x99063BCA,  0x000F6A70,  0x77085AE6,
        0xE7B74777,  0x90B077E1,  0x09B9265B,  0x7EBE16CD,
        0xE0DA836E,  0x97DDB3F8,  0x0ED4E242,  0x79D3D2D4,
        0xF4DBDF21,  0x83DCEFB7,  0x1AD5BE0D,  0x6DD28E9B,
        0xF3B61B38,  0x84B12BAE,  0x1DB87A14,  0x6ABF4A82,
        0xFA005713,  0x8D076785,  0x140E363F,  0x630906A9,
        0xFD6D930A,  0x8A6AA39C,  0x1363F226,  0x6464C2B0,
        0xA4DEAE1D,  0xD3D99E8B,  0x4AD0CF31,  0x3DD7FFA7,
        0xA3B36A04,  0xD4B45A92,  0x4DBD0B28,  0x3ABA3BBE,
        0xAA05262F,  0xDD0216B9,  0x440B4703,  0x330C7795,
        0xAD68E236,  0xDA6FD2A0,  0x4366831A,  0x3461B38C,
        0xB969BE79,  0xCE6E8EEF,  0x5767DF55,  0x2060EFC3,
        0xBE047A60,  0xC9034AF6,  0x500A1B4C,  0x270D2BDA,
        0xB7B2364B,  0xC0B506DD,  0x59BC5767,  0x2EBB67F1,
        0xB0DFF252,  0xC7D8C2C4,  0x5ED1937E,  0x29D6A3E8,
        0x9FB08ED5,  0xE8B7BE43,  0x71BEEFF9,  0x06B9DF6F,
        0x98DD4ACC,  0xEFDA7A5A,  0x76D32BE0,  0x01D41B76,
        0x916B06E7,  0xE66C3671,  0x7F6567CB,  0x0862575D,
        0x9606C2FE,  0xE101F268,  0x7808A3D2,  0x0F0F9344,
        0x82079EB1,  0xF500AE27,  0x6C09FF9D,  0x1B0ECF0B,
        0x856A5AA8,  0xF26D6A3E,  0x6B643B84,  0x1C630B12,
        0x8CDC1683,  0xFBDB2615,  0x62D277AF,  0x15D54739,
        0x8BB1D29A,  0xFCB6E20C,  0x65BFB3B6,  0x12B88320,
        0x3FBA6CAD,  0x48BD5C3B,  0xD1B40D81,  0xA6B33D17,
        0x38D7A8B4,  0x4FD09822,  0xD6D9C998,  0xA1DEF90E,
        0x3161E49F,  0x4666D409,  0xDF6F85B3,  0xA868B525,
        0x360C2086,  0x410B1010,  0xD80241AA,  0xAF05713C,
        0x220D7CC9,  0x550A4C5F,  0xCC031DE5,  0xBB042D73,
        0x2560B8D0,  0x52678846,  0xCB6ED9FC,  0xBC69E96A,
        0x2CD6F4FB,  0x5BD1C46D,  0xC2D895D7,  0xB5DFA541,
        0x2BBB30E2,  0x5CBC0074,  0xC5B551CE,  0xB2B26158,
        0x04D44C65,  0x73D37CF3,  0xEADA2D49,  0x9DDD1DDF,
        0x03B9887C,  0x74BEB8EA,  0xEDB7E950,  0x9AB0D9C6,
        0x0A0FC457,  0x7D08F4C1,  0xE401A57B,  0x930695ED,
        0x0D62004E,  0x7A6530D8,  0xE36C6162,  0x946B51F4,
        0x19635C01,  0x6E646C97,  0xF76D3D2D,  0x806A0DBB,
        0x1E0E9818,  0x6909A88E,  0xF000F934,  0x8707C9A2,
        0x17B8D433,  0x60BFE4A5,  0xF9B6B51F,  0x8EB18589,
        0x10D5102A,  0x67D220BC,  0xFEDB7106,  0x89DC4190,
        0x49662D3D,  0x3E611DAB,  0xA7684C11,  0xD06F7C87,
        0x4E0BE924,  0x390CD9B2,  0xA0058808,  0xD702B89E,
        0x47BDA50F,  0x30BA9599,  0xA9B3C423,  0xDEB4F4B5,
        0x40D06116,  0x37D75180,  0xAEDE003A,  0xD9D930AC,
        0x54D13D59,  0x23D60DCF,  0xBADF5C75,  0xCDD86CE3,
        0x53BCF940,  0x24BBC9D6,  0xBDB2986C,  0xCAB5A8FA,
        0x5A0AB56B,  0x2D0D85FD,  0xB404D447,  0xC303E4D1,
        0x5D677172,  0x2A6041E4,  0xB369105E,  0xC46E20C8,
        0x72080DF5,  0x050F3D63,  0x9C066CD9,  0xEB015C4F,
        0x7565C9EC,  0x0262F97A,  0x9B6BA8C0,  0xEC6C9856,
        0x7CD385C7,  0x0BD4B551,  0x92DDE4EB,  0xE5DAD47D,
        0x7BBE41DE,  0x0CB97148,  0x95B020F2,  0xE2B71064,
        0x6FBF1D91,  0x18B82D07,  0x81B17CBD,  0xF6B64C2B,
        0x68D2D988,  0x1FD5E91E,  0x86DCB8A4,  0xF1DB8832,
        0x616495A3,  0x1663A535,  0x8F6AF48F,  0xF86DC419,
        0x660951BA,  0x110E612C,  0x88073096,  0xFF000000
};