• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 <asm/io.h>
17 
dma_alloc_coherent(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp)18 void *dma_alloc_coherent(struct device *dev, size_t size,
19 			   dma_addr_t *dma_handle, gfp_t gfp)
20 {
21 	void *ret;
22 	int order = get_order(size);
23 	/* ignore region specifiers */
24 	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
25 
26 	if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
27 		return ret;
28 
29 	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
30 		gfp |= GFP_DMA;
31 
32 	ret = (void *)__get_free_pages(gfp, order);
33 
34 	if (ret != NULL) {
35 		memset(ret, 0, size);
36 		*dma_handle = virt_to_phys(ret);
37 	}
38 	return ret;
39 }
40 
dma_free_coherent(struct device * dev,size_t size,void * vaddr,dma_addr_t dma_handle)41 void dma_free_coherent(struct device *dev, size_t size,
42 			 void *vaddr, dma_addr_t dma_handle)
43 {
44 	int order = get_order(size);
45 
46 	if (!dma_release_from_coherent(dev, order, vaddr))
47 		free_pages((unsigned long)vaddr, order);
48 }
49 
50