[PATCH v3 08/19] crypto: arm/ghash - use the new scatterwalk functions

Eric Biggers
2025-02-19T18:24:29Z

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 <ebiggers@google.com>
---
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 3af9970825340..9613ffed84f93 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);
--
2.48.1