Showing error 411

User: Jiri Slaby
Error type: BUG/WARNING
Error type description: An unsatisfied assertion in the code
File location: arch/x86/kernel/pci-nommu.c
Line in file: 62
Project: Linux Kernel
Project version: 2.6.28
Tools: Web Crawler (0.1)
URL: https://bugzilla.kernel.org/show_bug.cgi?id=12320
Entered: 2011-09-08 08:49:13 UTC

Source: 

 1/* Fallback functions when the main IOMMU code is not compiled in. This
 2   code is roughly equivalent to i386. */
 3#include <linux/mm.h>
 4#include <linux/init.h>
 5#include <linux/pci.h>
 6#include <linux/string.h>
 7#include <linux/dma-mapping.h>
 8#include <linux/scatterlist.h>
 9
10#include <asm/iommu.h>
11#include <asm/processor.h>
12#include <asm/dma.h>
13
14static int
15check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
16{
17        if (hwdev && !is_buffer_dma_capable(*hwdev->dma_mask, bus, size)) {
18                if (*hwdev->dma_mask >= DMA_32BIT_MASK)
19                        printk(KERN_ERR
20                            "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
21                                name, (long long)bus, size,
22                                (long long)*hwdev->dma_mask);
23                return 0;
24        }
25        return 1;
26}
27
28static dma_addr_t
29nommu_map_single(struct device *hwdev, phys_addr_t paddr, size_t size,
30               int direction)
31{
32        dma_addr_t bus = paddr;
33        WARN_ON(size == 0);
34        if (!check_addr("map_single", hwdev, bus, size))
35                                return bad_dma_address;
36        flush_write_buffers();
37        return bus;
38}
39
40
41/* Map a set of buffers described by scatterlist in streaming
42 * mode for DMA.  This is the scatter-gather version of the
43 * above pci_map_single interface.  Here the scatter gather list
44 * elements are each tagged with the appropriate dma address
45 * and length.  They are obtained via sg_dma_{address,length}(SG).
46 *
47 * NOTE: An implementation may be able to use a smaller number of
48 *       DMA address/length pairs than there are SG table elements.
49 *       (for example via virtual mapping capabilities)
50 *       The routine returns the number of addr/length pairs actually
51 *       used, at most nents.
52 *
53 * Device ownership issues as mentioned above for pci_map_single are
54 * the same here.
55 */
56static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
57               int nents, int direction)
58{
59        struct scatterlist *s;
60        int i;
61
62        WARN_ON(nents == 0 || sg[0].length == 0);
63
64        for_each_sg(sg, s, nents, i) {
65                BUG_ON(!sg_page(s));
66                s->dma_address = sg_phys(s);
67                if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
68                        return 0;
69                s->dma_length = s->length;
70        }
71        flush_write_buffers();
72        return nents;
73}
74
75static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
76                                dma_addr_t dma_addr)
77{
78        free_pages((unsigned long)vaddr, get_order(size));
79}
80
81struct dma_mapping_ops nommu_dma_ops = {
82        .alloc_coherent = dma_generic_alloc_coherent,
83        .free_coherent = nommu_free_coherent,
84        .map_single = nommu_map_single,
85        .map_sg = nommu_map_sg,
86        .is_phys = 1,
87};
88
89void __init no_iommu_init(void)
90{
91        if (dma_ops)
92                return;
93
94        force_iommu = 0; /* no HW IOMMU */
95        dma_ops = &nommu_dma_ops;
96}
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