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authorDaniel Vetter <daniel.vetter@ffwll.ch>2013-03-19 04:47:30 -0400
committerDaniel Vetter <daniel.vetter@ffwll.ch>2013-03-19 04:47:30 -0400
commit0d4a42f6bd298e826620585e766a154ab460617a (patch)
tree406d8f7778691d858dbe3e48e4bbb10e99c0a58a /include/linux/scatterlist.h
parentd62b4892f3d9f7dd2002e5309be10719d6805b0f (diff)
parenta937536b868b8369b98967929045f1df54234323 (diff)
Merge tag 'v3.9-rc3' into drm-intel-next-queued
Backmerge so that I can merge Imre Deak's coalesced sg entries fixes, which depend upon the new for_each_sg_page introduce in commit a321e91b6d73ed011ffceed384c40d2785cf723b Author: Imre Deak <imre.deak@intel.com> Date: Wed Feb 27 17:02:56 2013 -0800 lib/scatterlist: add simple page iterator The merge itself is just two trivial conflicts: Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'include/linux/scatterlist.h')
-rw-r--r--include/linux/scatterlist.h41
1 files changed, 38 insertions, 3 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 4bd6c06eb28e..2d8bdaef9611 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -231,6 +231,41 @@ size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
231 */ 231 */
232#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist)) 232#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
233 233
234/*
235 * sg page iterator
236 *
237 * Iterates over sg entries page-by-page. On each successful iteration,
238 * @piter->page points to the current page, @piter->sg to the sg holding this
239 * page and @piter->sg_pgoffset to the page's page offset within the sg. The
240 * iteration will stop either when a maximum number of sg entries was reached
241 * or a terminating sg (sg_last(sg) == true) was reached.
242 */
243struct sg_page_iter {
244 struct page *page; /* current page */
245 struct scatterlist *sg; /* sg holding the page */
246 unsigned int sg_pgoffset; /* page offset within the sg */
247
248 /* these are internal states, keep away */
249 unsigned int __nents; /* remaining sg entries */
250 int __pg_advance; /* nr pages to advance at the
251 * next step */
252};
253
254bool __sg_page_iter_next(struct sg_page_iter *piter);
255void __sg_page_iter_start(struct sg_page_iter *piter,
256 struct scatterlist *sglist, unsigned int nents,
257 unsigned long pgoffset);
258
259/**
260 * for_each_sg_page - iterate over the pages of the given sg list
261 * @sglist: sglist to iterate over
262 * @piter: page iterator to hold current page, sg, sg_pgoffset
263 * @nents: maximum number of sg entries to iterate over
264 * @pgoffset: starting page offset
265 */
266#define for_each_sg_page(sglist, piter, nents, pgoffset) \
267 for (__sg_page_iter_start((piter), (sglist), (nents), (pgoffset)); \
268 __sg_page_iter_next(piter);)
234 269
235/* 270/*
236 * Mapping sg iterator 271 * Mapping sg iterator
@@ -258,11 +293,11 @@ struct sg_mapping_iter {
258 void *addr; /* pointer to the mapped area */ 293 void *addr; /* pointer to the mapped area */
259 size_t length; /* length of the mapped area */ 294 size_t length; /* length of the mapped area */
260 size_t consumed; /* number of consumed bytes */ 295 size_t consumed; /* number of consumed bytes */
296 struct sg_page_iter piter; /* page iterator */
261 297
262 /* these are internal states, keep away */ 298 /* these are internal states, keep away */
263 struct scatterlist *__sg; /* current entry */ 299 unsigned int __offset; /* offset within page */
264 unsigned int __nents; /* nr of remaining entries */ 300 unsigned int __remaining; /* remaining bytes on page */
265 unsigned int __offset; /* offset within sg */
266 unsigned int __flags; 301 unsigned int __flags;
267}; 302};
268 303