kernel/2.6.29.6-aldebaran-rt/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 <asm/io.h>
  17
  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
  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