/*
   * Dynamic DMA mapping support.
   *
   * On cris there is no hardware dynamic DMA address translation,
   * so consistent alloc/free are merely page allocation/freeing.
   * The rest of the dynamic DMA mapping interface is implemented
   * in asm/pci.h.
   *
   * Borrowed from i386.
   */
  
  #include <linux/types.h>
  #include <linux/mm.h>
  #include <linux/string.h>
  #include <linux/pci.h>
  #include <linux/gfp.h>
  #include <asm/io.h>
  
  void *dma_alloc_coherent(struct device *dev, size_t size,
  			   dma_addr_t *dma_handle, gfp_t gfp)
  {
  	void *ret;
  	int order = get_order(size);
  	/* ignore region specifiers */
  	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
  
  	if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
  		return ret;
  
  	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
  		gfp |= GFP_DMA;
  
  	ret = (void *)__get_free_pages(gfp, order);
  
  	if (ret != NULL) {
  		memset(ret, 0, size);
  		*dma_handle = virt_to_phys(ret);
  	}
  	return ret;
  }
  
  void dma_free_coherent(struct device *dev, size_t size,
  			 void *vaddr, dma_addr_t dma_handle)
  {
  	int order = get_order(size);
  
  	if (!dma_release_from_coherent(dev, order, vaddr))
  		free_pages((unsigned long)vaddr, order);
  }