| 172,6 → 172,22 |
|---|
| } |
| |
| /** |
| * sg_unmark_end - Undo setting the end of the scatterlist |
| * @sg: SG entryScatterlist |
| * |
| * Description: |
| * Removes the termination marker from the given entry of the scatterlist. |
| * |
| **/ |
| static inline void sg_unmark_end(struct scatterlist *sg) |
| { |
| #ifdef CONFIG_DEBUG_SG |
| BUG_ON(sg->sg_magic != SG_MAGIC); |
| #endif |
| sg->page_link &= ~0x02; |
| } |
| |
| /** |
| * sg_phys - Return physical address of an sg entry |
| * @sg: SG entry |
| * |
| 231,7 → 247,60 |
|---|
| */ |
| #define SG_MAX_SINGLE_ALLOC (4*PAGE_SIZE / sizeof(struct scatterlist)) |
| |
| /* |
| * sg page iterator |
| * |
| * Iterates over sg entries page-by-page. On each successful iteration, |
| * you can call sg_page_iter_page(@piter) and sg_page_iter_dma_address(@piter) |
| * to get the current page and its dma address. @piter->sg will point to the |
| * sg holding this page and @piter->sg_pgoffset to the page's page offset |
| * within the sg. The iteration will stop either when a maximum number of sg |
| * entries was reached or a terminating sg (sg_last(sg) == true) was reached. |
| */ |
| struct sg_page_iter { |
| struct scatterlist *sg; /* sg holding the page */ |
| unsigned int sg_pgoffset; /* page offset within the sg */ |
| |
| /* these are internal states, keep away */ |
| unsigned int __nents; /* remaining sg entries */ |
| int __pg_advance; /* nr pages to advance at the |
| * next step */ |
| }; |
| |
| bool __sg_page_iter_next(struct sg_page_iter *piter); |
| void __sg_page_iter_start(struct sg_page_iter *piter, |
| struct scatterlist *sglist, unsigned int nents, |
| unsigned long pgoffset); |
| /** |
| * sg_page_iter_page - get the current page held by the page iterator |
| * @piter: page iterator holding the page |
| */ |
| static inline struct page *sg_page_iter_page(struct sg_page_iter *piter) |
| { |
| return nth_page(sg_page(piter->sg), piter->sg_pgoffset); |
| } |
| |
| /** |
| * sg_page_iter_dma_address - get the dma address of the current page held by |
| * the page iterator. |
| * @piter: page iterator holding the page |
| */ |
| static inline dma_addr_t sg_page_iter_dma_address(struct sg_page_iter *piter) |
| { |
| return sg_dma_address(piter->sg) + (piter->sg_pgoffset << PAGE_SHIFT); |
| } |
| |
| /** |
| * for_each_sg_page - iterate over the pages of the given sg list |
| * @sglist: sglist to iterate over |
| * @piter: page iterator to hold current page, sg, sg_pgoffset |
| * @nents: maximum number of sg entries to iterate over |
| * @pgoffset: starting page offset |
| */ |
| #define for_each_sg_page(sglist, piter, nents, pgoffset) \ |
| for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \ |
| __sg_page_iter_next(piter);) |
| |
| /* |
| * Mapping sg iterator |
| * |
| 258,11 → 327,11 |
|---|
| void *addr; /* pointer to the mapped area */ |
| size_t length; /* length of the mapped area */ |
| size_t consumed; /* number of consumed bytes */ |
| struct sg_page_iter piter; /* page iterator */ |
| |
| /* these are internal states, keep away */ |
| struct scatterlist *__sg; /* current entry */ |
| unsigned int __nents; /* nr of remaining entries */ |
| unsigned int __offset; /* offset within sg */ |
| unsigned int __offset; /* offset within page */ |
| unsigned int __remaining; /* remaining bytes on page */ |
| unsigned int __flags; |
| }; |
| |