#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 */