Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* Fallback functions when the main IOMMU code is not compiled in. This |
2 | code is roughly equivalent to i386. */ | |
8fa3d6fc | 3 | #include <linux/dma-mapping.h> |
b922f53b | 4 | #include <linux/scatterlist.h> |
1894e367 JSR |
5 | #include <linux/string.h> |
6 | #include <linux/init.h> | |
5a0e3ad6 | 7 | #include <linux/gfp.h> |
1894e367 JSR |
8 | #include <linux/pci.h> |
9 | #include <linux/mm.h> | |
8fa3d6fc | 10 | |
1da177e4 | 11 | #include <asm/processor.h> |
1894e367 | 12 | #include <asm/iommu.h> |
17a941d8 | 13 | #include <asm/dma.h> |
1da177e4 | 14 | |
17a941d8 MBY |
15 | static int |
16 | check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size) | |
1da177e4 | 17 | { |
a4c2baa6 | 18 | if (hwdev && !dma_capable(hwdev, bus, size)) { |
284901a9 | 19 | if (*hwdev->dma_mask >= DMA_BIT_MASK(32)) |
f0fdabf8 | 20 | printk(KERN_ERR |
8fa3d6fc AM |
21 | "nommu_%s: overflow %Lx+%zu of device mask %Lx\n", |
22 | name, (long long)bus, size, | |
23 | (long long)*hwdev->dma_mask); | |
17a941d8 | 24 | return 0; |
1da177e4 | 25 | } |
17a941d8 MBY |
26 | return 1; |
27 | } | |
1da177e4 | 28 | |
33feffd4 FT |
29 | static dma_addr_t nommu_map_page(struct device *dev, struct page *page, |
30 | unsigned long offset, size_t size, | |
31 | enum dma_data_direction dir, | |
32 | struct dma_attrs *attrs) | |
17a941d8 | 33 | { |
33feffd4 | 34 | dma_addr_t bus = page_to_phys(page) + offset; |
5b3e5b72 | 35 | WARN_ON(size == 0); |
33feffd4 | 36 | if (!check_addr("map_single", dev, bus, size)) |
8fd524b3 | 37 | return DMA_ERROR_CODE; |
e4dcdd6b | 38 | flush_write_buffers(); |
17a941d8 | 39 | return bus; |
1da177e4 | 40 | } |
1da177e4 | 41 | |
17a941d8 MBY |
42 | /* Map a set of buffers described by scatterlist in streaming |
43 | * mode for DMA. This is the scatter-gather version of the | |
44 | * above pci_map_single interface. Here the scatter gather list | |
45 | * elements are each tagged with the appropriate dma address | |
46 | * and length. They are obtained via sg_dma_{address,length}(SG). | |
47 | * | |
48 | * NOTE: An implementation may be able to use a smaller number of | |
49 | * DMA address/length pairs than there are SG table elements. | |
50 | * (for example via virtual mapping capabilities) | |
51 | * The routine returns the number of addr/length pairs actually | |
52 | * used, at most nents. | |
53 | * | |
54 | * Device ownership issues as mentioned above for pci_map_single are | |
55 | * the same here. | |
56 | */ | |
1048fa52 | 57 | static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg, |
160c1d8e FT |
58 | int nents, enum dma_data_direction dir, |
59 | struct dma_attrs *attrs) | |
1da177e4 | 60 | { |
b922f53b | 61 | struct scatterlist *s; |
17a941d8 | 62 | int i; |
1da177e4 | 63 | |
5b3e5b72 GC |
64 | WARN_ON(nents == 0 || sg[0].length == 0); |
65 | ||
b922f53b | 66 | for_each_sg(sg, s, nents, i) { |
58b053e4 | 67 | BUG_ON(!sg_page(s)); |
30db2cbf | 68 | s->dma_address = sg_phys(s); |
17a941d8 MBY |
69 | if (!check_addr("map_sg", hwdev, s->dma_address, s->length)) |
70 | return 0; | |
71 | s->dma_length = s->length; | |
72 | } | |
e4dcdd6b | 73 | flush_write_buffers(); |
17a941d8 MBY |
74 | return nents; |
75 | } | |
1da177e4 | 76 | |
a8ad568d AB |
77 | static void nommu_sync_single_for_device(struct device *dev, |
78 | dma_addr_t addr, size_t size, | |
79 | enum dma_data_direction dir) | |
80 | { | |
81 | flush_write_buffers(); | |
82 | } | |
83 | ||
84 | ||
85 | static void nommu_sync_sg_for_device(struct device *dev, | |
86 | struct scatterlist *sg, int nelems, | |
87 | enum dma_data_direction dir) | |
88 | { | |
89 | flush_write_buffers(); | |
90 | } | |
91 | ||
160c1d8e | 92 | struct dma_map_ops nommu_dma_ops = { |
baa676fc | 93 | .alloc = dma_generic_alloc_coherent, |
0a2b9a6e | 94 | .free = dma_generic_free_coherent, |
a8ad568d AB |
95 | .map_sg = nommu_map_sg, |
96 | .map_page = nommu_map_page, | |
97 | .sync_single_for_device = nommu_sync_single_for_device, | |
98 | .sync_sg_for_device = nommu_sync_sg_for_device, | |
99 | .is_phys = 1, | |
17a941d8 | 100 | }; |