crypto: caam - Fix incorrect size when DMA unmapping buffer

The CAAM driver uses two data buffers to store data for a hashing operation,
with one buffer defined as active. This change forces switching of the
active buffer when executing a hashing operation to avoid a later DMA unmap
using the length of the opposite buffer.
Signed-off-by: Victoria Milhoan <vicki.milhoan@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/caamhash.c

@@ -835,17 +835,17 @@ static int ahash_update_ctx(struct ahash_request *req)
 			src_map_to_sec4_sg(jrdev, req->src, src_nents,
 					   edesc->sec4_sg + sec4_sg_src_index,
 					   chained);
-			if (*next_buflen) {
+			if (*next_buflen)
 				scatterwalk_map_and_copy(next_buf, req->src,
 							 to_hash - *buflen,
 							 *next_buflen, 0);
-				state->current_buf = !state->current_buf;
-			}
 		} else {
 			(edesc->sec4_sg + sec4_sg_src_index - 1)->len |=
 							SEC4_SG_LEN_FIN;
 		}
 
+		state->current_buf = !state->current_buf;
+
 		sh_len = desc_len(sh_desc);
 		desc = edesc->hw_desc;
 		init_job_desc_shared(desc, ptr, sh_len, HDR_SHARE_DEFER |
@@ -1268,9 +1268,10 @@ static int ahash_update_no_ctx(struct ahash_request *req)
 			scatterwalk_map_and_copy(next_buf, req->src,
 						 to_hash - *buflen,
 						 *next_buflen, 0);
-			state->current_buf = !state->current_buf;
 		}
 
+		state->current_buf = !state->current_buf;
+
 		sh_len = desc_len(sh_desc);
 		desc = edesc->hw_desc;
 		init_job_desc_shared(desc, ptr, sh_len, HDR_SHARE_DEFER |