1 /*
2 * Dynamic DMA mapping support.
3 *
4 * We never have any address translations to worry about, so this
5 * is just alloc/free.
6 */
7
8 #include <linux/types.h>
9 #include <linux/mm.h>
10 #include <linux/string.h>
11 #include <linux/device.h>
12 #include <asm/io.h>
13
dma_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,int gfp)14 void *dma_alloc_coherent(struct device *dev, size_t size,
15 dma_addr_t *dma_handle, int gfp)
16 {
17 void *ret;
18 /* ignore region specifiers */
19 gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
20
21 if (dev == NULL || (*dev->dma_mask < 0xffffffff))
22 gfp |= GFP_DMA;
23 ret = (void *)__get_free_pages(gfp, get_order(size));
24
25 if (ret != NULL) {
26 memset(ret, 0, size);
27 *dma_handle = virt_to_phys(ret);
28 }
29 return ret;
30 }
31
dma_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle)32 void dma_free_coherent(struct device *dev, size_t size,
33 void *vaddr, dma_addr_t dma_handle)
34 {
35 free_pages((unsigned long)vaddr, get_order(size));
36 }
37