+ return (++sg)->length ? sg : (void *)sg->page;
+}
+
+static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
+ struct scatter_walk *walk_out)
+{
+ return !(((walk_in->sg->page - walk_out->sg->page) << PAGE_SHIFT) +
+ (int)(walk_in->offset - walk_out->offset));
+}
+
+static inline unsigned int scatterwalk_pagelen(struct scatter_walk *walk)
+{
+ unsigned int len = walk->sg->offset + walk->sg->length - walk->offset;
+ unsigned int len_this_page = offset_in_page(~walk->offset) + 1;
+ return len_this_page > len ? len : len_this_page;
+}
+
+static inline unsigned int scatterwalk_clamp(struct scatter_walk *walk,
+ unsigned int nbytes)
+{
+ unsigned int len_this_page = scatterwalk_pagelen(walk);
+ return nbytes > len_this_page ? len_this_page : nbytes;
+}
+
+static inline void scatterwalk_advance(struct scatter_walk *walk,
+ unsigned int nbytes)
+{
+ walk->offset += nbytes;
+}
+
+static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
+ unsigned int alignmask)
+{
+ return !(walk->offset & alignmask);
+}
+
+static inline struct page *scatterwalk_page(struct scatter_walk *walk)
+{
+ return walk->sg->page + (walk->offset >> PAGE_SHIFT);