|  | #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; | 
|  | unsigned int	dma_length; | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * 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) | 
|  | #ifndef sg_dma_len | 
|  | /* | 
|  | * Normally, you have an iommu on 64 bit machines, but not on 32 bit | 
|  | * machines. Architectures that are differnt should override this. | 
|  | */ | 
|  | #if __BITS_PER_LONG == 64 | 
|  | #define sg_dma_len(sg)		((sg)->dma_length) | 
|  | #else | 
|  | #define sg_dma_len(sg)		((sg)->length) | 
|  | #endif /* 64 bit */ | 
|  | #endif /* sg_dma_len */ | 
|  |  | 
|  | #ifndef ISA_DMA_THRESHOLD | 
|  | #define ISA_DMA_THRESHOLD	(~0UL) | 
|  | #endif | 
|  |  | 
|  | #define ARCH_HAS_SG_CHAIN | 
|  |  | 
|  | #endif /* __ASM_GENERIC_SCATTERLIST_H */ |