LXR linux/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
  18void *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
  41void 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