1 files changed, 40 insertions, 49 deletions

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 2953e2cc56f0..35172d3f043b 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -15,9 +15,11 @@
  */
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/module.h>
 #include <linux/pagemap.h>
 #include <linux/highmem.h>
-#include <asm/scatterlist.h>
+#include <linux/scatterlist.h>
+
 #include "internal.h"
 #include "scatterwalk.h"
 
@@ -27,88 +29,77 @@ enum km_type crypto_km_types[] = {
         KM_SOFTIRQ0,
         KM_SOFTIRQ1,
 };
+EXPORT_SYMBOL_GPL(crypto_km_types);
 
-static void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
+static inline void memcpy_dir(void *buf, void *sgdata, size_t nbytes, int out)
 {
-        if (out)
-                memcpy(sgdata, buf, nbytes);
-        else
-                memcpy(buf, sgdata, nbytes);
+        void *src = out ? buf : sgdata;
+        void *dst = out ? sgdata : buf;
+
+        memcpy(dst, src, nbytes);
 }
 
 void scatterwalk_start(struct scatter_walk *walk, struct scatterlist *sg)
 {
-        unsigned int rest_of_page;
-
         walk->sg = sg;
 
-        walk->page = sg->page;
-        walk->len_this_segment = sg->length;
-
         BUG_ON(!sg->length);
 
-        rest_of_page = PAGE_CACHE_SIZE - (sg->offset & (PAGE_CACHE_SIZE - 1));
-        walk->len_this_page = min(sg->length, rest_of_page);
         walk->offset = sg->offset;
 }
+EXPORT_SYMBOL_GPL(scatterwalk_start);
 
-void scatterwalk_map(struct scatter_walk *walk, int out)
-{
-        walk->data = crypto_kmap(walk->page, out) + walk->offset;
-}
-
-static inline void scatterwalk_unmap(struct scatter_walk *walk, int out)
+void *scatterwalk_map(struct scatter_walk *walk, int out)
 {
-        /* walk->data may be pointing the first byte of the next page;
-           however, we know we transfered at least one byte.  So,
-           walk->data - 1 will be a virtual address in the mapped page. */
-        crypto_kunmap(walk->data - 1, out);
+        return crypto_kmap(scatterwalk_page(walk), out) +
+               offset_in_page(walk->offset);
 }
+EXPORT_SYMBOL_GPL(scatterwalk_map);
 
 static void scatterwalk_pagedone(struct scatter_walk *walk, int out,
                                  unsigned int more)
 {
         if (out)
-                flush_dcache_page(walk->page);
+                flush_dcache_page(scatterwalk_page(walk));
 
         if (more) {
-                walk->len_this_segment -= walk->len_this_page;
-
-                if (walk->len_this_segment) {
-                        walk->page++;
-                        walk->len_this_page = min(walk->len_this_segment,
-                                                  (unsigned)PAGE_CACHE_SIZE);
-                        walk->offset = 0;
-                }
-                else
+                walk->offset += PAGE_SIZE - 1;
+                walk->offset &= PAGE_MASK;
+                if (walk->offset >= walk->sg->offset + walk->sg->length)
                         scatterwalk_start(walk, sg_next(walk->sg));
         }
 }
 
 void scatterwalk_done(struct scatter_walk *walk, int out, int more)
 {
-        scatterwalk_unmap(walk, out);
-        if (walk->len_this_page == 0 || !more)
+        if (!offset_in_page(walk->offset) || !more)
                 scatterwalk_pagedone(walk, out, more);
 }
+EXPORT_SYMBOL_GPL(scatterwalk_done);
 
-/*
- * Do not call this unless the total length of all of the fragments
- * has been verified as multiple of the block size.
- */
-int scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
-                           size_t nbytes, int out)
+void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
+                            size_t nbytes, int out)
 {
-        while (nbytes > walk->len_this_page) {
-                memcpy_dir(buf, walk->data, walk->len_this_page, out);
-                buf += walk->len_this_page;
-                nbytes -= walk->len_this_page;
+        for (;;) {
+                unsigned int len_this_page = scatterwalk_pagelen(walk);
+                u8 *vaddr;
+
+                if (len_this_page > nbytes)
+                        len_this_page = nbytes;
+
+                vaddr = scatterwalk_map(walk, out);
+                memcpy_dir(buf, vaddr, len_this_page, out);
+                scatterwalk_unmap(vaddr, out);
+
+                if (nbytes == len_this_page)
+                        break;
+
+                buf += len_this_page;
+                nbytes -= len_this_page;
 
-                scatterwalk_unmap(walk, out);
                 scatterwalk_pagedone(walk, out, 1);
-                scatterwalk_map(walk, out);
         }
 
-        memcpy_dir(buf, walk->data, nbytes, out);
-        return nbytes;
+        scatterwalk_advance(walk, nbytes);
 }
+EXPORT_SYMBOL_GPL(scatterwalk_copychunks);