diff options
Diffstat (limited to 'include/linux/scatterlist.h')
| -rw-r--r-- | include/linux/scatterlist.h | 39 |
1 files changed, 32 insertions, 7 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index a0edb992c9c3..50a8486c524b 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -2,13 +2,39 @@ #define _LINUX_SCATTERLIST_H #include <linux/string.h> +#include <linux/types.h> #include <linux/bug.h> #include <linux/mm.h> - -#include <asm/types.h> -#include <asm/scatterlist.h> #include <asm/io.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 dma_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 + struct sg_table { struct scatterlist *sgl; /* the list */ unsigned int nents; /* number of mapped entries */ @@ -18,10 +44,9 @@ struct sg_table { /* * Notes on SG table design. * - * Architectures must provide an unsigned long page_link field in the - * scatterlist struct. We use that to place the page pointer AND encode - * information about the sg table as well. The two lower bits are reserved - * for this information. + * We use the unsigned long page_link field in the scatterlist struct to place + * the page pointer AND encode information about the sg table as well. The two + * lower bits are reserved for this information. * * If bit 0 is set, then the page_link contains a pointer to the next sg * table list. Otherwise the next entry is at sg + 1. |