1 /*
2 * Dynamic DMA mapping support.
3 *
4 * On cris there is no hardware dynamic DMA address translation,
5 * so consistent alloc/free are merely page allocation/freeing.
6 * The rest of the dynamic DMA mapping interface is implemented
7 * in asm/pci.h.
8 *
9 * Borrowed from i386.
10 */
11
12 #include <linux/types.h>
13 #include <linux/mm.h>
14 #include <linux/string.h>
15 #include <linux/pci.h>
16 #include <linux/gfp.h>
17 #include <asm/io.h>
18
dma_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp)19 void *dma_alloc_coherent(struct device *dev, size_t size,
20 dma_addr_t *dma_handle, gfp_t gfp)
21 {
22 void *ret;
23 int order = get_order(size);
24 /* ignore region specifiers */
25 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
26
27 if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
28 return ret;
29
30 if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
31 gfp |= GFP_DMA;
32
33 ret = (void *)__get_free_pages(gfp, order);
34
35 if (ret != NULL) {
36 memset(ret, 0, size);
37 *dma_handle = virt_to_phys(ret);
38 }
39 return ret;
40 }
41
dma_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle)42 void dma_free_coherent(struct device *dev, size_t size,
43 void *vaddr, dma_addr_t dma_handle)
44 {
45 int order = get_order(size);
46
47 if (!dma_release_from_coherent(dev, order, vaddr))
48 free_pages((unsigned long)vaddr, order);
49 }
50
51