diff options
| author | Tomasz Stanislawski <t.stanislaws@samsung.com> | 2012-06-18 09:25:01 +0200 |
|---|---|---|
| committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2012-07-30 12:25:44 +0200 |
| commit | efc42bc98058a36d761b16a114823db1a902ed05 (patch) | |
| tree | 3ba9403ec5b4a8619bde6a7fd1eaa3c14843ad3d /include/linux/scatterlist.h | |
| parent | 28a33cbc24e4256c143dce96c7d93bf423229f92 (diff) | |
scatterlist: add sg_alloc_table_from_pages function
This patch adds a new constructor for an sg table. The table is constructed
from an array of struct pages. All contiguous chunks of the pages are merged
into a single sg nodes. A user may provide an offset and a size of a buffer if
the buffer is not page-aligned.
The function is dedicated for DMABUF exporters which often perform conversion
from an page array to a scatterlist. Moreover the scatterlist should be
squashed in order to save memory and to speed-up the process of DMA mapping
using dma_map_sg.
The code is based on the patch 'v4l: vb2-dma-contig: add support for
scatterlist in userptr mode' and hints from Laurent Pinchart.
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
CC: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/scatterlist.h')
| -rw-r--r-- | include/linux/scatterlist.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index ac9586dadfa..7b600da9a63 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -214,6 +214,10 @@ void sg_free_table(struct sg_table *); int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int, gfp_t, sg_alloc_fn *); int sg_alloc_table(struct sg_table *, unsigned int, gfp_t); +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); size_t sg_copy_from_buffer(struct scatterlist *sgl, unsigned int nents, void *buf, size_t buflen); |