#ifndef __ASM_GENERIC_SCATTERLIST_H
  #define __ASM_GENERIC_SCATTERLIST_H
  
  #include <linux/types.h>
  
  struct scatterlist {
  #ifdef CONFIG_DEBUG_SG
  	unsigned long	sg_magic;
  #endif
  	unsigned long	page_link;
  	unsigned int	offset;
  	unsigned int	length;
  	dma_addr_t	dma_address;

  #ifdef CONFIG_NEED_SG_DMA_LENGTH

  	unsigned int	dma_length;

  #endif

  };
  
  /*
   * These macros should be used after a dma_map_sg call has been done
   * to get bus addresses of each of the SG entries and their lengths.
   * You should only work with the number of sg entries pci_map_sg
   * returns, or alternatively stop on the first sg_dma_len(sg) which
   * is 0.
   */
  #define sg_dma_address(sg)	((sg)->dma_address)

  
  #ifdef CONFIG_NEED_SG_DMA_LENGTH

  #define sg_dma_len(sg)		((sg)->dma_length)
  #else
  #define sg_dma_len(sg)		((sg)->length)

  #endif

  #endif /* __ASM_GENERIC_SCATTERLIST_H */