Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* Fallback functions when the main IOMMU code is not compiled in. This |
3 | code is roughly equivalent to i386. */ | |
ea8c64ac | 4 | #include <linux/dma-direct.h> |
b922f53b | 5 | #include <linux/scatterlist.h> |
1894e367 | 6 | #include <linux/string.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 | |
14a9aad7 CH |
15 | #define NOMMU_MAPPING_ERROR 0 |
16 | ||
17a941d8 MBY |
17 | static int |
18 | check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size) | |
1da177e4 | 19 | { |
a4c2baa6 | 20 | if (hwdev && !dma_capable(hwdev, bus, size)) { |
284901a9 | 21 | if (*hwdev->dma_mask >= DMA_BIT_MASK(32)) |
f0fdabf8 | 22 | printk(KERN_ERR |
8fa3d6fc AM |
23 | "nommu_%s: overflow %Lx+%zu of device mask %Lx\n", |
24 | name, (long long)bus, size, | |
25 | (long long)*hwdev->dma_mask); | |
17a941d8 | 26 | return 0; |
1da177e4 | 27 | } |
17a941d8 MBY |
28 | return 1; |
29 | } | |
1da177e4 | 30 | |
33feffd4 FT |
31 | static dma_addr_t nommu_map_page(struct device *dev, struct page *page, |
32 | unsigned long offset, size_t size, | |
33 | enum dma_data_direction dir, | |
00085f1e | 34 | unsigned long attrs) |
17a941d8 | 35 | { |
c7753208 | 36 | dma_addr_t bus = phys_to_dma(dev, page_to_phys(page)) + offset; |
5b3e5b72 | 37 | WARN_ON(size == 0); |
33feffd4 | 38 | if (!check_addr("map_single", dev, bus, size)) |
14a9aad7 | 39 | return NOMMU_MAPPING_ERROR; |
e4dcdd6b | 40 | flush_write_buffers(); |
17a941d8 | 41 | return bus; |
1da177e4 | 42 | } |
1da177e4 | 43 | |
17a941d8 MBY |
44 | /* Map a set of buffers described by scatterlist in streaming |
45 | * mode for DMA. This is the scatter-gather version of the | |
46 | * above pci_map_single interface. Here the scatter gather list | |
47 | * elements are each tagged with the appropriate dma address | |
48 | * and length. They are obtained via sg_dma_{address,length}(SG). | |
49 | * | |
50 | * NOTE: An implementation may be able to use a smaller number of | |
51 | * DMA address/length pairs than there are SG table elements. | |
52 | * (for example via virtual mapping capabilities) | |
53 | * The routine returns the number of addr/length pairs actually | |
54 | * used, at most nents. | |
55 | * | |
56 | * Device ownership issues as mentioned above for pci_map_single are | |
57 | * the same here. | |
58 | */ | |
1048fa52 | 59 | static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg, |
160c1d8e | 60 | int nents, enum dma_data_direction dir, |
00085f1e | 61 | unsigned long attrs) |
1da177e4 | 62 | { |
b922f53b | 63 | struct scatterlist *s; |
17a941d8 | 64 | int i; |
1da177e4 | 65 | |
5b3e5b72 GC |
66 | WARN_ON(nents == 0 || sg[0].length == 0); |
67 | ||
b922f53b | 68 | for_each_sg(sg, s, nents, i) { |
58b053e4 | 69 | BUG_ON(!sg_page(s)); |
30db2cbf | 70 | s->dma_address = sg_phys(s); |
17a941d8 MBY |
71 | if (!check_addr("map_sg", hwdev, s->dma_address, s->length)) |
72 | return 0; | |
73 | s->dma_length = s->length; | |
74 | } | |
e4dcdd6b | 75 | flush_write_buffers(); |
17a941d8 MBY |
76 | return nents; |
77 | } | |
1da177e4 | 78 | |
a8ad568d AB |
79 | static void nommu_sync_single_for_device(struct device *dev, |
80 | dma_addr_t addr, size_t size, | |
81 | enum dma_data_direction dir) | |
82 | { | |
83 | flush_write_buffers(); | |
84 | } | |
85 | ||
86 | ||
87 | static void nommu_sync_sg_for_device(struct device *dev, | |
88 | struct scatterlist *sg, int nelems, | |
89 | enum dma_data_direction dir) | |
90 | { | |
91 | flush_write_buffers(); | |
92 | } | |
93 | ||
14a9aad7 CH |
94 | static int nommu_mapping_error(struct device *dev, dma_addr_t dma_addr) |
95 | { | |
96 | return dma_addr == NOMMU_MAPPING_ERROR; | |
97 | } | |
98 | ||
5299709d | 99 | const struct dma_map_ops nommu_dma_ops = { |
baa676fc | 100 | .alloc = dma_generic_alloc_coherent, |
0a2b9a6e | 101 | .free = dma_generic_free_coherent, |
a8ad568d AB |
102 | .map_sg = nommu_map_sg, |
103 | .map_page = nommu_map_page, | |
104 | .sync_single_for_device = nommu_sync_single_for_device, | |
105 | .sync_sg_for_device = nommu_sync_sg_for_device, | |
106 | .is_phys = 1, | |
14a9aad7 | 107 | .mapping_error = nommu_mapping_error, |
5860acc1 | 108 | .dma_supported = x86_dma_supported, |
17a941d8 | 109 | }; |