Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

[~andy/linux] / include / linux / scatterlist.h

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index bfc47e0de81c6ad52e50050dd2d2acdb6c746112..5951e3f38878398d36eef96e0482ebae15bf8409 100644 (file)
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -251,13 +251,13 @@ size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents,
  * sg page iterator
  *
  * Iterates over sg entries page-by-page.  On each successful iteration,
- * @piter->page points to the current page, @piter->sg 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.
+ * 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 page             *page;          /* current page */
        struct scatterlist      *sg;            /* sg holding the page */
        unsigned int            sg_pgoffset;    /* page offset within the sg */
 
@@ -271,6 +271,24 @@ 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