#ifndef _ASM_X86_DMA_MAPPING_H
  #define _ASM_X86_DMA_MAPPING_H

  
  /*

   * IOMMU interface. See Documentation/DMA-API-HOWTO.txt and

   * Documentation/DMA-API.txt for documentation.

   */

  #include <linux/kmemcheck.h>

  #include <linux/scatterlist.h>

  #include <linux/dma-debug.h>

  #include <linux/dma-attrs.h>

  #include <asm/io.h>
  #include <asm/swiotlb.h>

  #include <asm-generic/dma-coherent.h>

  #ifdef CONFIG_ISA
  # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
  #else
  # define ISA_DMA_BIT_MASK DMA_BIT_MASK(32)
  #endif

  #define DMA_ERROR_CODE	0

  extern int iommu_merge;

  extern struct device x86_dma_fallback_dev;

  extern int panic_on_overflow;

  extern struct dma_map_ops *dma_ops;
  
  static inline struct dma_map_ops *get_dma_ops(struct device *dev)

  {

  #ifdef CONFIG_X86_32
  	return dma_ops;
  #else
  	if (unlikely(!dev) || !dev->archdata.dma_ops)
  		return dma_ops;
  	else
  		return dev->archdata.dma_ops;

  #endif

  }

  #include <asm-generic/dma-mapping-common.h>

  /* Make sure we keep the same behaviour */
  static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
  {

  	struct dma_map_ops *ops = get_dma_ops(dev);

  	if (ops->mapping_error)
  		return ops->mapping_error(dev, dma_addr);

  	return (dma_addr == DMA_ERROR_CODE);

  }

  #define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
  #define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)

  extern int dma_supported(struct device *hwdev, u64 mask);
  extern int dma_set_mask(struct device *dev, u64 mask);

  extern void *dma_generic_alloc_coherent(struct device *dev, size_t size,
  					dma_addr_t *dma_addr, gfp_t flag);

  static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
  {
  	if (!dev->dma_mask)
  		return 0;

  	return addr + size - 1 <= *dev->dma_mask;

  }

  static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
  {
  	return paddr;
  }
  
  static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
  {
  	return daddr;
  }

  static inline void
  dma_cache_sync(struct device *dev, void *vaddr, size_t size,
  	enum dma_data_direction dir)
  {
  	flush_write_buffers();
  }

  static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
  						    gfp_t gfp)
  {
  	unsigned long dma_mask = 0;

  	dma_mask = dev->coherent_dma_mask;
  	if (!dma_mask)

  		dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);

  
  	return dma_mask;
  }
  
  static inline gfp_t dma_alloc_coherent_gfp_flags(struct device *dev, gfp_t gfp)
  {
  	unsigned long dma_mask = dma_alloc_coherent_mask(dev, gfp);

  	if (dma_mask <= DMA_BIT_MASK(24))

  		gfp |= GFP_DMA;
  #ifdef CONFIG_X86_64

  	if (dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))

  		gfp |= GFP_DMA32;
  #endif
         return gfp;
  }

  static inline void *
  dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
  		gfp_t gfp)
  {

  	struct dma_map_ops *ops = get_dma_ops(dev);

  	void *memory;

  	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);

  	if (dma_alloc_from_coherent(dev, size, dma_handle, &memory))
  		return memory;

  	if (!dev)

  		dev = &x86_dma_fallback_dev;

  	if (!is_device_dma_capable(dev))

  		return NULL;

  	if (!ops->alloc_coherent)
  		return NULL;

  	memory = ops->alloc_coherent(dev, size, dma_handle,
  				     dma_alloc_coherent_gfp_flags(dev, gfp));
  	debug_dma_alloc_coherent(dev, size, *dma_handle, memory);
  
  	return memory;

  }
  
  static inline void dma_free_coherent(struct device *dev, size_t size,
  				     void *vaddr, dma_addr_t bus)
  {

  	struct dma_map_ops *ops = get_dma_ops(dev);

  
  	WARN_ON(irqs_disabled());       /* for portability */
  
  	if (dma_release_from_coherent(dev, get_order(size), vaddr))
  		return;

  	debug_dma_free_coherent(dev, size, vaddr, bus);

  	if (ops->free_coherent)
  		ops->free_coherent(dev, size, vaddr, bus);
  }

  #endif