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[24/29] crypto: x86/aes-gcm - use the new scatterwalk functions

Message ID 20241221091056.282098-25-ebiggers@kernel.org (mailing list archive)
State Under Review
Delegated to: Herbert Xu
Headers show
Series crypto: scatterlist handling improvements | expand

Commit Message

Eric Biggers Dec. 21, 2024, 9:10 a.m. UTC
From: Eric Biggers <ebiggers@google.com>

In gcm_process_assoc(), use scatterwalk_next() which consolidates
scatterwalk_clamp() and scatterwalk_map().  Use scatterwalk_done_src()
which consolidates scatterwalk_unmap(), scatterwalk_advance(), and
scatterwalk_done().

Also rename some variables to avoid implying that anything is actually
mapped (it's not), or that the loop is going page by page (it is for
now, but nothing actually requires that to be the case).

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 arch/x86/crypto/aesni-intel_glue.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)
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Patch

diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index fbf43482e1f5..c65d44b037b5 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -1289,45 +1289,45 @@  static void gcm_process_assoc(const struct aes_gcm_key *key, u8 ghash_acc[16],
 
 	memset(ghash_acc, 0, 16);
 	scatterwalk_start(&walk, sg_src);
 
 	while (assoclen) {
-		unsigned int len_this_page = scatterwalk_clamp(&walk, assoclen);
-		void *mapped = scatterwalk_map(&walk);
-		const void *src = mapped;
+		unsigned int orig_len_this_step;
+		const u8 *orig_src = scatterwalk_next(&walk, assoclen,
+						      &orig_len_this_step);
+		unsigned int len_this_step = orig_len_this_step;
 		unsigned int len;
+		const u8 *src = orig_src;
 
-		assoclen -= len_this_page;
-		scatterwalk_advance(&walk, len_this_page);
 		if (unlikely(pos)) {
-			len = min(len_this_page, 16 - pos);
+			len = min(len_this_step, 16 - pos);
 			memcpy(&buf[pos], src, len);
 			pos += len;
 			src += len;
-			len_this_page -= len;
+			len_this_step -= len;
 			if (pos < 16)
 				goto next;
 			aes_gcm_aad_update(key, ghash_acc, buf, 16, flags);
 			pos = 0;
 		}
-		len = len_this_page;
+		len = len_this_step;
 		if (unlikely(assoclen)) /* Not the last segment yet? */
 			len = round_down(len, 16);
 		aes_gcm_aad_update(key, ghash_acc, src, len, flags);
 		src += len;
-		len_this_page -= len;
-		if (unlikely(len_this_page)) {
-			memcpy(buf, src, len_this_page);
-			pos = len_this_page;
+		len_this_step -= len;
+		if (unlikely(len_this_step)) {
+			memcpy(buf, src, len_this_step);
+			pos = len_this_step;
 		}
 next:
-		scatterwalk_unmap(mapped);
-		scatterwalk_pagedone(&walk, 0, assoclen);
+		scatterwalk_done_src(&walk, orig_src, orig_len_this_step);
 		if (need_resched()) {
 			kernel_fpu_end();
 			kernel_fpu_begin();
 		}
+		assoclen -= orig_len_this_step;
 	}
 	if (unlikely(pos))
 		aes_gcm_aad_update(key, ghash_acc, buf, pos, flags);
 }