arch/cris/arch-v32/drivers/pci/dma.c

   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
  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
  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