commit 85eccddee401ae81067e763516889780b5545160
author Herbert Xu <herbert@gondor.apana.org.au> Tue Jul 12 13:17:55 2016 +0800
committer Herbert Xu <herbert@gondor.apana.org.au> Mon Jul 18 17:35:48 2016 +0800
tree 2ed2c98edfbe965640dd75a73bdabce37e4479c7
parent 5506f53c7cc17c4ad5e69e5512a35faf77182986

crypto: scatterwalk - Add no-copy support to copychunks

The function ablkcipher_done_slow is pretty much identical to
scatterwalk_copychunks except that it doesn't actually copy as
the processing hasn't been completed yet.

This patch allows scatterwalk_copychunks to be used in this case
by specifying out == 2.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/scatterwalk.c

diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c
index 03ca4ae..e124ce2 100644
--- a/crypto/scatterwalk.c
+++ b/crypto/scatterwalk.c
@@ -87,9 +87,11 @@
 		if (len_this_page > nbytes)
 			len_this_page = nbytes;
 
-		vaddr = scatterwalk_map(walk);
-		memcpy_dir(buf, vaddr, len_this_page, out);
-		scatterwalk_unmap(vaddr);
+		if (out != 2) {
+			vaddr = scatterwalk_map(walk);
+			memcpy_dir(buf, vaddr, len_this_page, out);
+			scatterwalk_unmap(vaddr);
+		}
 
 		scatterwalk_advance(walk, len_this_page);
 
@@ -99,7 +101,7 @@
 		buf += len_this_page;
 		nbytes -= len_this_page;
 
-		scatterwalk_pagedone(walk, out, 1);
+		scatterwalk_pagedone(walk, out & 1, 1);
 	}
 }
 EXPORT_SYMBOL_GPL(scatterwalk_copychunks);