linux/arch/m68knommu/kernel/dma.c
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   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
  14void *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
  32void 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