projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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, | |
| 13 | struct dma_attrs *attrs) | |
| 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, | |
| 25 | struct dma_attrs *attrs) | |
| 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, | |
| 33 | struct dma_attrs *attrs) | |
| 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, | |
| 39 | enum dma_data_direction dir, struct dma_attrs *attrs) | |
| 40 | { | |
| 41 | int i; | |
| 42 | struct scatterlist *sg; | |
| 43 | ||
| 44 | for_each_sg(sgl, sg, nents, i) { | |
| 45 | void *va; | |
| 46 | ||
| 47 | BUG_ON(!sg_page(sg)); | |
| 48 | va = sg_virt(sg); | |
| 49 | sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va); | |
| 50 | sg_dma_len(sg) = sg->length; | |
| 51 | } | |
| 52 | ||
| 53 | return nents; | |
| 54 | } | |
| 55 | ||
| 56 | static int dma_noop_mapping_error(struct device *dev, dma_addr_t dma_addr) | |
| 57 | { | |
| 58 | return 0; | |
| 59 | } | |
| 60 | ||
| 61 | static int dma_noop_supported(struct device *dev, u64 mask) | |
| 62 | { | |
| 63 | return 1; | |
| 64 | } | |
| 65 | ||
| 66 | struct dma_map_ops dma_noop_ops = { | |
| 67 | .alloc = dma_noop_alloc, | |
| 68 | .free = dma_noop_free, | |
| 69 | .map_page = dma_noop_map_page, | |
| 70 | .map_sg = dma_noop_map_sg, | |
| 71 | .mapping_error = dma_noop_mapping_error, | |
| 72 | .dma_supported = dma_noop_supported, | |
| 73 | }; | |
| 74 | ||
| 75 | EXPORT_SYMBOL(dma_noop_ops); |