Subject: [PATCH v2 18/29] crypto: arm/ghash - use the new scatterwalk functions

From: Eric Biggers <[email-masked]>
Date: Sun, 29 Dec 2024 16:14:07 -0800

From: Eric Biggers <[email-masked]>

Use scatterwalk_next() which consolidates scatterwalk_clamp() and
scatterwalk_map(), and use scatterwalk_done_src() which consolidates
scatterwalk_unmap(), scatterwalk_advance(), and scatterwalk_done().
Remove unnecessary code that seemed to be intended to advance to the
next sg entry, which is already handled by the scatterwalk functions.

Signed-off-by: Eric Biggers <[email-masked]>
---
 arch/arm/crypto/ghash-ce-glue.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/arch/arm/crypto/ghash-ce-glue.c b/arch/arm/crypto/ghash-ce-glue.c
index 3af997082534..9613ffed84f9 100644
--- a/arch/arm/crypto/ghash-ce-glue.c
+++ b/arch/arm/crypto/ghash-ce-glue.c
@@ -457,30 +457,23 @@ static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[], u32 len)
 	int buf_count = 0;
 
 	scatterwalk_start(&walk, req->src);
 
 	do {
-		u32 n = scatterwalk_clamp(&walk, len);
-		u8 *p;
+		unsigned int n;
+		const u8 *p;
 
-		if (!n) {
-			scatterwalk_start(&walk, sg_next(walk.sg));
-			n = scatterwalk_clamp(&walk, len);
-		}
-
-		p = scatterwalk_map(&walk);
+		p = scatterwalk_next(&walk, len, &n);
 		gcm_update_mac(dg, p, n, buf, &buf_count, ctx);
-		scatterwalk_unmap(p);
+		scatterwalk_done_src(&walk, p, n);
 
 		if (unlikely(len / SZ_4K > (len - n) / SZ_4K)) {
 			kernel_neon_end();
 			kernel_neon_begin();
 		}
 
 		len -= n;
-		scatterwalk_advance(&walk, n);
-		scatterwalk_done(&walk, 0, len);
 	} while (len);
 
 	if (buf_count) {
 		memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count);
 		pmull_ghash_update_p64(1, dg, buf, ctx->h, NULL);
-- 
2.47.1