1 files changed, 29 insertions, 19 deletions

diff --git a/crypto/scatterwalk.h b/crypto/scatterwalk.h
index e79925c474a3..ace595a2e119 100644
--- a/crypto/scatterwalk.h
+++ b/crypto/scatterwalk.h
@@ -14,17 +14,11 @@
 
 #ifndef _CRYPTO_SCATTERWALK_H
 #define _CRYPTO_SCATTERWALK_H
+
 #include <linux/mm.h>
-#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
 
-struct scatter_walk {
-        struct scatterlist      *sg;
-        struct page             *page;
-        void                    *data;
-        unsigned int            len_this_page;
-        unsigned int            len_this_segment;
-        unsigned int            offset;
-};
+#include "internal.h"
 
 /* Define sg_next is an inline routine now in case we want to change
    scatterlist to a linked list later. */
@@ -33,26 +27,31 @@ static inline struct scatterlist *sg_next(struct scatterlist *sg)
         return sg + 1;
 }
 
-static inline int scatterwalk_samebuf(struct scatter_walk *walk_in,
-                                      struct scatter_walk *walk_out)
+static inline unsigned long scatterwalk_samebuf(struct scatter_walk *walk_in,
+                                                struct scatter_walk *walk_out)
 {
-        return walk_in->page == walk_out->page &&
-               walk_in->offset == walk_out->offset;
+        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)
 {
-        return nbytes > walk->len_this_page ? walk->len_this_page : 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->data += nbytes;
         walk->offset += nbytes;
-        walk->len_this_page -= nbytes;
-        walk->len_this_segment -= nbytes;
 }
 
 static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
@@ -61,9 +60,20 @@ static inline unsigned int scatterwalk_aligned(struct scatter_walk *walk,
         return !(walk->offset & alignmask);
 }
 
+static inline struct page *scatterwalk_page(struct scatter_walk *walk)
+{
+        return walk->sg->page + (walk->offset >> PAGE_SHIFT);
+}
+
+static inline void scatterwalk_unmap(void *vaddr, int out)
+{
+        crypto_kunmap(vaddr, out);
+}
+
 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg);
-int scatterwalk_copychunks(void *buf, struct scatter_walk *walk, size_t nbytes, int out);
-void scatterwalk_map(struct scatter_walk *walk, int out);
+void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
+                            size_t nbytes, int out);
+void *scatterwalk_map(struct scatter_walk *walk, int out);
 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
 
 #endif  /* _CRYPTO_SCATTERWALK_H */