crypto: skcipher - use the new scatterwalk functions

Convert skcipher_walk to use the new scatterwalk functions.

This includes a few changes to exactly where the different parts of the
iteration happen.  For example the dcache flush that previously happened
in scatterwalk_done() now happens in scatterwalk_dst_done() or in
memcpy_to_scatterwalk().  Advancing to the next sg entry now happens
just-in-time in scatterwalk_clamp() instead of in scatterwalk_done().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/skcipher.c b/crypto/skcipher.c
index 59e33f63f8453b8432ffcbe1289cb264e5a368d2..e9b803fe24417be5cc62ad879641e6d8af9dcdef 100644 (file)
--- a/crypto/skcipher.c
+++ b/crypto/skcipher.c
@@ -49,16 +49,6 @@ static inline void skcipher_map_dst(struct skcipher_walk *walk)
        walk->dst.virt.addr = scatterwalk_map(&walk->out);
 }
 
-static inline void skcipher_unmap_src(struct skcipher_walk *walk)
-{
-       scatterwalk_unmap(walk->src.virt.addr);
-}
-
-static inline void skcipher_unmap_dst(struct skcipher_walk *walk)
-{
-       scatterwalk_unmap(walk->dst.virt.addr);
-}
-
 static inline gfp_t skcipher_walk_gfp(struct skcipher_walk *walk)
 {
        return walk->flags & SKCIPHER_WALK_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
@@ -70,14 +60,6 @@ static inline struct skcipher_alg *__crypto_skcipher_alg(
        return container_of(alg, struct skcipher_alg, base);
 }
 
-static int skcipher_done_slow(struct skcipher_walk *walk, unsigned int bsize)
-{
-       u8 *addr = PTR_ALIGN(walk->buffer, walk->alignmask + 1);
-
-       scatterwalk_copychunks(addr, &walk->out, bsize, 1);
-       return 0;
-}
-
 /**
  * skcipher_walk_done() - finish one step of a skcipher_walk
  * @walk: the skcipher_walk
@@ -112,15 +94,14 @@ int skcipher_walk_done(struct skcipher_walk *walk, int res)
        if (likely(!(walk->flags & (SKCIPHER_WALK_SLOW |
                                    SKCIPHER_WALK_COPY |
                                    SKCIPHER_WALK_DIFF)))) {
-unmap_src:
-               skcipher_unmap_src(walk);
+               scatterwalk_advance(&walk->in, n);
        } else if (walk->flags & SKCIPHER_WALK_DIFF) {
-               skcipher_unmap_dst(walk);
-               goto unmap_src;
+               scatterwalk_unmap(walk->src.virt.addr);
+               scatterwalk_advance(&walk->in, n);
        } else if (walk->flags & SKCIPHER_WALK_COPY) {
+               scatterwalk_advance(&walk->in, n);
                skcipher_map_dst(walk);
                memcpy(walk->dst.virt.addr, walk->page, n);
-               skcipher_unmap_dst(walk);
        } else { /* SKCIPHER_WALK_SLOW */
                if (res > 0) {
                        /*
@@ -131,21 +112,23 @@ unmap_src:
                         */
                        res = -EINVAL;
                        total = 0;
-               } else
-                       n = skcipher_done_slow(walk, n);
+               } else {
+                       u8 *buf = PTR_ALIGN(walk->buffer, walk->alignmask + 1);
+
+                       memcpy_to_scatterwalk(&walk->out, buf, n);
+               }
+               goto dst_done;
        }
 
+       scatterwalk_done_dst(&walk->out, walk->dst.virt.addr, n);
+dst_done:
+
        if (res > 0)
                res = 0;
 
        walk->total = total;
        walk->nbytes = 0;
 
-       scatterwalk_advance(&walk->in, n);
-       scatterwalk_advance(&walk->out, n);
-       scatterwalk_done(&walk->in, 0, total);
-       scatterwalk_done(&walk->out, 1, total);
-
        if (total) {
                if (walk->flags & SKCIPHER_WALK_SLEEP)
                        cond_resched();
@@ -192,7 +175,7 @@ static int skcipher_next_slow(struct skcipher_walk *walk, unsigned int bsize)
        walk->dst.virt.addr = PTR_ALIGN(buffer, alignmask + 1);
        walk->src.virt.addr = walk->dst.virt.addr;
 
-       scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
+       memcpy_from_scatterwalk(walk->src.virt.addr, &walk->in, bsize);
 
        walk->nbytes = bsize;
        walk->flags |= SKCIPHER_WALK_SLOW;
@@ -206,7 +189,11 @@ static int skcipher_next_copy(struct skcipher_walk *walk)
 
        skcipher_map_src(walk);
        memcpy(tmp, walk->src.virt.addr, walk->nbytes);
-       skcipher_unmap_src(walk);
+       scatterwalk_unmap(walk->src.virt.addr);
+       /*
+        * walk->in is advanced later when the number of bytes actually
+        * processed (which might be less than walk->nbytes) is known.
+        */
 
        walk->src.virt.addr = tmp;
        walk->dst.virt.addr = tmp;