|  | #ifndef _ASM_SCATTERLIST_H | 
|  | #define _ASM_SCATTERLIST_H | 
|  |  | 
|  | #include <asm/types.h> | 
|  |  | 
|  | /* | 
|  | * Drivers must set either ->address or (preferred) page and ->offset | 
|  | * to indicate where data must be transferred to/from. | 
|  | * | 
|  | * Using page is recommended since it handles highmem data as well as | 
|  | * low mem. ->address is restricted to data which has a virtual mapping, and | 
|  | * it will go away in the future. Updating to page can be automated very | 
|  | * easily -- something like | 
|  | * | 
|  | * sg->address = some_ptr; | 
|  | * | 
|  | * can be rewritten as | 
|  | * | 
|  | * sg_set_buf(sg, some_ptr, length); | 
|  | * | 
|  | * and that's it. There's no excuse for not highmem enabling YOUR driver. /jens | 
|  | */ | 
|  | struct scatterlist { | 
|  | #ifdef CONFIG_DEBUG_SG | 
|  | unsigned long	sg_magic; | 
|  | #endif | 
|  | unsigned long	page_link; | 
|  | unsigned int	offset;		/* for highmem, page offset */ | 
|  |  | 
|  | dma_addr_t	dma_address; | 
|  | unsigned int	length; | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * These macros should be used after a pci_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) | 
|  | #define sg_dma_len(sg)		((sg)->length) | 
|  |  | 
|  | #define ISA_DMA_THRESHOLD (0xffffffffUL) | 
|  |  | 
|  | #endif /* !_ASM_SCATTERLIST_H */ |