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Diffstat (limited to 'arch/frv/include/asm/scatterlist.h')
-rw-r--r-- | arch/frv/include/asm/scatterlist.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/arch/frv/include/asm/scatterlist.h b/arch/frv/include/asm/scatterlist.h new file mode 100644 index 00000000000..4bca8a28546 --- /dev/null +++ b/arch/frv/include/asm/scatterlist.h @@ -0,0 +1,46 @@ +#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 */ |