Commit | Line | Data |
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a8463d4b CB |
1 | /* |
2 | * lib/dma-noop.c | |
3 | * | |
4 | * Simple DMA noop-ops that map 1:1 with memory | |
5 | */ | |
6 | #include <linux/export.h> | |
7 | #include <linux/mm.h> | |
8 | #include <linux/dma-mapping.h> | |
9 | #include <linux/scatterlist.h> | |
10 | ||
11 | static void *dma_noop_alloc(struct device *dev, size_t size, | |
12 | dma_addr_t *dma_handle, gfp_t gfp, | |
00085f1e | 13 | unsigned long attrs) |
a8463d4b CB |
14 | { |
15 | void *ret; | |
16 | ||
17 | ret = (void *)__get_free_pages(gfp, get_order(size)); | |
18 | if (ret) | |
19 | *dma_handle = virt_to_phys(ret); | |
20 | return ret; | |
21 | } | |
22 | ||
23 | static void dma_noop_free(struct device *dev, size_t size, | |
24 | void *cpu_addr, dma_addr_t dma_addr, | |
00085f1e | 25 | unsigned long attrs) |
a8463d4b CB |
26 | { |
27 | free_pages((unsigned long)cpu_addr, get_order(size)); | |
28 | } | |
29 | ||
30 | static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page, | |
31 | unsigned long offset, size_t size, | |
32 | enum dma_data_direction dir, | |
00085f1e | 33 | unsigned long attrs) |
a8463d4b CB |
34 | { |
35 | return page_to_phys(page) + offset; | |
36 | } | |
37 | ||
38 | static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nents, | |
00085f1e KK |
39 | enum dma_data_direction dir, |
40 | unsigned long attrs) | |
a8463d4b CB |
41 | { |
42 | int i; | |
43 | struct scatterlist *sg; | |
44 | ||
45 | for_each_sg(sgl, sg, nents, i) { | |
46 | void *va; | |
47 | ||
48 | BUG_ON(!sg_page(sg)); | |
49 | va = sg_virt(sg); | |
50 | sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va); | |
51 | sg_dma_len(sg) = sg->length; | |
52 | } | |
53 | ||
54 | return nents; | |
55 | } | |
56 | ||
57 | static int dma_noop_mapping_error(struct device *dev, dma_addr_t dma_addr) | |
58 | { | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static int dma_noop_supported(struct device *dev, u64 mask) | |
63 | { | |
64 | return 1; | |
65 | } | |
66 | ||
67 | struct dma_map_ops dma_noop_ops = { | |
68 | .alloc = dma_noop_alloc, | |
69 | .free = dma_noop_free, | |
70 | .map_page = dma_noop_map_page, | |
71 | .map_sg = dma_noop_map_sg, | |
72 | .mapping_error = dma_noop_mapping_error, | |
73 | .dma_supported = dma_noop_supported, | |
74 | }; | |
75 | ||
76 | EXPORT_SYMBOL(dma_noop_ops); |