[PATCH 08/11] crypto: sun4i-ss: use GENMASK to generate masks

[Antoine Tenart]

Use the GENMASK helper instead of custom calculations to generate masks,
It also helps the readability.

Signed-off-by: Antoine Tenart <antoine.ten...@free-electrons.com>
---
 drivers/crypto/sunxi-ss/sun4i-ss-hash.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c 
b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
index 0c2efc88bc0a..685de5b6ab17 100644
--- a/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
+++ b/drivers/crypto/sunxi-ss/sun4i-ss-hash.c
@@ -384,11 +384,14 @@ static int sun4i_hash(struct ahash_request *areq)
                        writesl(ss->base + SS_RXFIFO, op->buf, nwait);
                        op->byte_count += 4 * nwait;
                }
+
                nbw = op->len - 4 * nwait;
-               wb = *(u32 *)(op->buf + nwait * 4);
-               wb &= (0xFFFFFFFF >> (4 - nbw) * 8);
+               if (nbw) {
+                       wb = *(u32 *)(op->buf + nwait * 4);
+                       wb &= GENMASK((nbw * 8) - 1, 0);
 
-               op->byte_count += nbw;
+                       op->byte_count += nbw;
+               }
        }
 
        /* write the remaining bytes of the nbw buffer */
-- 
2.9.4