1 files changed, 36 insertions, 11 deletions

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index d6852c33cfb..79ca2278c2a 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -13,6 +13,8 @@
  * any later version.
  *
  */
+
+#include <crypto/scatterwalk.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/module.h>
@@ -20,9 +22,6 @@
 #include <linux/highmem.h>
 #include <linux/scatterlist.h>
 
-#include "internal.h"
-#include "scatterwalk.h"
-
 static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
 {
 	void *src = out ? buf : sgdata;
@@ -41,9 +40,9 @@ void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg)
 }
 EXPORT_SYMBOL_GPL(scatterwalk_start);
 
-void *scatterwalk_map(struct scatter_walk *walk, int out)
+void *scatterwalk_map(struct scatter_walk *walk)
 {
-	return crypto_kmap(scatterwalk_page(walk), out) +
+	return kmap_atomic(scatterwalk_page(walk)) +
 	       offset_in_page(walk->offset);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_map);
@@ -54,8 +53,9 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
 	if (out) {
 		struct page *page;
 
-		page = walk->sg->page + ((walk->offset - 1) >> PAGE_SHIFT);
-		flush_dcache_page(page);
+		page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT);
+		if (!PageSlab(page))
+			flush_dcache_page(page);
 	}
 
 	if (more) {
@@ -68,7 +68,7 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
 
 void scatterwalk_done(struct scatter_walk *walk, int out, int more)
 {
-	if (!offset_in_page(walk->offset) || !more)
+	if (!(scatterwalk_pagelen(walk) & (PAGE_SIZE - 1)) || !more)
 		scatterwalk_pagedone(walk, out, more);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_done);
@@ -83,9 +83,9 @@ void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
 		if (len_this_page > nbytes)
 			len_this_page = nbytes;
 
-		vaddr = scatterwalk_map(walk, out);
+		vaddr = scatterwalk_map(walk);
 		memcpy_dir(buf, vaddr, len_this_page, out);
-		scatterwalk_unmap(vaddr, out);
+		scatterwalk_unmap(vaddr);
 
 		scatterwalk_advance(walk, len_this_page);
 
@@ -106,6 +106,9 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 	struct scatter_walk walk;
 	unsigned int offset = 0;
 
+	if (!nbytes)
+		return;
+
 	for (;;) {
 		scatterwalk_start(&walk, sg);
 
@@ -113,7 +116,7 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 			break;
 
 		offset += sg->length;
-		sg = sg_next(sg);
+		sg = scatterwalk_sg_next(sg);
 	}
 
 	scatterwalk_advance(&walk, start - offset);
@@ -121,3 +124,25 @@ void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
 	scatterwalk_done(&walk, out, 0);
 }
 EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
+
+int scatterwalk_bytes_sglen(struct scatterlist *sg, int num_bytes)
+{
+	int offset = 0, n = 0;
+
+	/* num_bytes is too small */
+	if (num_bytes < sg->length)
+		return -1;
+
+	do {
+		offset += sg->length;
+		n++;
+		sg = scatterwalk_sg_next(sg);
+
+		/* num_bytes is too large */
+		if (unlikely(!sg && (num_bytes < offset)))
+			return -1;
+	} while (sg && (num_bytes > offset));
+
+	return n;
+}
+EXPORT_SYMBOL_GPL(scatterwalk_bytes_sglen);