Merge remote-tracking branch 'asoc/fix/intel' into asoc-linus
[linux-2.6-microblaze.git] / lib / dma-virt.c
1 /*
2  *      lib/dma-virt.c
3  *
4  * DMA operations that map to virtual addresses without flushing 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_virt_alloc(struct device *dev, size_t size,
12                             dma_addr_t *dma_handle, gfp_t gfp,
13                             unsigned long attrs)
14 {
15         void *ret;
16
17         ret = (void *)__get_free_pages(gfp, get_order(size));
18         if (ret)
19                 *dma_handle = (uintptr_t)ret;
20         return ret;
21 }
22
23 static void dma_virt_free(struct device *dev, size_t size,
24                           void *cpu_addr, dma_addr_t dma_addr,
25                           unsigned long attrs)
26 {
27         free_pages((unsigned long)cpu_addr, get_order(size));
28 }
29
30 static dma_addr_t dma_virt_map_page(struct device *dev, struct page *page,
31                                     unsigned long offset, size_t size,
32                                     enum dma_data_direction dir,
33                                     unsigned long attrs)
34 {
35         return (uintptr_t)(page_address(page) + offset);
36 }
37
38 static int dma_virt_map_sg(struct device *dev, struct scatterlist *sgl,
39                            int nents, enum dma_data_direction dir,
40                            unsigned long attrs)
41 {
42         int i;
43         struct scatterlist *sg;
44
45         for_each_sg(sgl, sg, nents, i) {
46                 BUG_ON(!sg_page(sg));
47                 sg_dma_address(sg) = (uintptr_t)sg_virt(sg);
48                 sg_dma_len(sg) = sg->length;
49         }
50
51         return nents;
52 }
53
54 const struct dma_map_ops dma_virt_ops = {
55         .alloc                  = dma_virt_alloc,
56         .free                   = dma_virt_free,
57         .map_page               = dma_virt_map_page,
58         .map_sg                 = dma_virt_map_sg,
59 };
60 EXPORT_SYMBOL(dma_virt_ops);