#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 */