| 349,9 → 349,70 |
|---|
| } |
| EXPORT_SYMBOL(sg_alloc_table); |
| |
| /** |
| * sg_alloc_table_from_pages - Allocate and initialize an sg table from |
| * an array of pages |
| * @sgt: The sg table header to use |
| * @pages: Pointer to an array of page pointers |
| * @n_pages: Number of pages in the pages array |
| * @offset: Offset from start of the first page to the start of a buffer |
| * @size: Number of valid bytes in the buffer (after offset) |
| * @gfp_mask: GFP allocation mask |
| * |
| * Description: |
| * Allocate and initialize an sg table from a list of pages. Contiguous |
| * ranges of the pages are squashed into a single scatterlist node. A user |
| * may provide an offset at a start and a size of valid data in a buffer |
| * specified by the page array. The returned sg table is released by |
| * sg_free_table. |
| * |
| * Returns: |
| * 0 on success, negative error on failure |
| */ |
| int sg_alloc_table_from_pages(struct sg_table *sgt, |
| struct page **pages, unsigned int n_pages, |
| unsigned long offset, unsigned long size, |
| gfp_t gfp_mask) |
| { |
| unsigned int chunks; |
| unsigned int i; |
| unsigned int cur_page; |
| int ret; |
| struct scatterlist *s; |
| |
| /* compute number of contiguous chunks */ |
| chunks = 1; |
| for (i = 1; i < n_pages; ++i) |
| if (page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) |
| ++chunks; |
| |
| ret = sg_alloc_table(sgt, chunks, gfp_mask); |
| if (unlikely(ret)) |
| return ret; |
| |
| /* merging chunks and putting them into the scatterlist */ |
| cur_page = 0; |
| for_each_sg(sgt->sgl, s, sgt->orig_nents, i) { |
| unsigned long chunk_size; |
| unsigned int j; |
| |
| /* look for the end of the current chunk */ |
| for (j = cur_page + 1; j < n_pages; ++j) |
| if (page_to_pfn(pages[j]) != |
| page_to_pfn(pages[j - 1]) + 1) |
| break; |
| |
| chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset; |
| sg_set_page(s, pages[cur_page], min(size, chunk_size), offset); |
| size -= chunk_size; |
| offset = 0; |
| cur_page = j; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(sg_alloc_table_from_pages); |
| |
| void __sg_page_iter_start(struct sg_page_iter *piter, |
| struct scatterlist *sglist, unsigned int nents, |
| unsigned long pgoffset) |