[PATCH 1/9] lib/crypto: arm64/aes: Remove obsolete chunking logic

Eric Biggers
2026-04-01T00:07:49Z

Simplify the AES-CBC-MAC code accordingly.

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
arch/arm64/crypto/aes-ce-ccm-glue.c | 13 ++++-------
include/crypto/aes.h | 6 ++---
lib/crypto/arm64/aes-modes.S | 8 +++----
lib/crypto/arm64/aes.h | 35 +++++++++++------------------
4 files changed, 23 insertions(+), 39 deletions(-)

diff --git a/arch/arm64/crypto/aes-ce-ccm-glue.c b/arch/arm64/crypto/aes-ce-ccm-glue.c
index 45aed0073283..a304375ce724 100644
--- a/arch/arm64/crypto/aes-ce-ccm-glue.c
+++ b/arch/arm64/crypto/aes-ce-ccm-glue.c
@@ -99,20 +99,15 @@ static u32 ce_aes_ccm_auth_data(u8 mac[], u8 const in[], u32 abytes,

do {
u32 blocks = abytes / AES_BLOCK_SIZE;

if (macp == AES_BLOCK_SIZE || (!macp && blocks > 0)) {
- u32 rem = ce_aes_mac_update(in, rk, rounds, blocks, mac,
- macp, enc_after);
- u32 adv = (blocks - rem) * AES_BLOCK_SIZE;
-
+ ce_aes_mac_update(in, rk, rounds, blocks, mac, macp,
+ enc_after);
macp = enc_after ? 0 : AES_BLOCK_SIZE;
- in += adv;
- abytes -= adv;
-
- if (unlikely(rem))
- macp = 0;
+ in += blocks * AES_BLOCK_SIZE;
+ abytes -= blocks * AES_BLOCK_SIZE;
} else {
u32 l = min(AES_BLOCK_SIZE - macp, abytes);

crypto_xor(&mac[macp], in, l);
in += l;
diff --git a/include/crypto/aes.h b/include/crypto/aes.h
index 3feb4105c2a2..16fbfd93e2bd 100644
--- a/include/crypto/aes.h
+++ b/include/crypto/aes.h
@@ -228,13 +228,13 @@ asmlinkage void ce_aes_essiv_cbc_encrypt(u8 out[], u8 const in[],
u32 const rk1[], int rounds,
int blocks, u8 iv[], u32 const rk2[]);
asmlinkage void ce_aes_essiv_cbc_decrypt(u8 out[], u8 const in[],
u32 const rk1[], int rounds,
int blocks, u8 iv[], u32 const rk2[]);
-asmlinkage size_t ce_aes_mac_update(u8 const in[], u32 const rk[], int rounds,
- size_t blocks, u8 dg[], int enc_before,
- int enc_after);
+asmlinkage void ce_aes_mac_update(u8 const in[], u32 const rk[], int rounds,
+ size_t blocks, u8 dg[], int enc_before,
+ int enc_after);
#elif defined(CONFIG_PPC)
void ppc_expand_key_128(u32 *key_enc, const u8 *key);
void ppc_expand_key_192(u32 *key_enc, const u8 *key);
void ppc_expand_key_256(u32 *key_enc, const u8 *key);
void ppc_generate_decrypt_key(u32 *key_dec, u32 *key_enc, unsigned int key_len);
diff --git a/lib/crypto/arm64/aes-modes.S b/lib/crypto/arm64/aes-modes.S
index fc89cd02b642..10e537317eaf 100644
--- a/lib/crypto/arm64/aes-modes.S
+++ b/lib/crypto/arm64/aes-modes.S
@@ -815,13 +815,13 @@ AES_FUNC_START(aes_xts_decrypt)
b .Lxtsdecctsout
AES_FUNC_END(aes_xts_decrypt)

#if IS_ENABLED(CONFIG_CRYPTO_LIB_AES_CBC_MACS)
/*
- * size_t aes_mac_update(u8 const in[], u32 const rk[], int rounds,
- * size_t blocks, u8 dg[], int enc_before,
- * int enc_after);
+ * void aes_mac_update(u8 const in[], u32 const rk[], int rounds,
+ * size_t blocks, u8 dg[], int enc_before,
+ * int enc_after);
*/
AES_FUNC_START(aes_mac_update)
ld1 {v0.16b}, [x4] /* get dg */
enc_prepare w2, x1, x7
cbz w5, .Lmacloop4x
@@ -842,11 +842,10 @@ AES_FUNC_START(aes_mac_update)
cmp x3, xzr
csinv w5, w6, wzr, eq
cbz w5, .Lmacout
encrypt_block v0, w2, x1, x7, w8
st1 {v0.16b}, [x4] /* return dg */
- cond_yield .Lmacout, x7, x8
b .Lmacloop4x
.Lmac1x:
add x3, x3, #4
.Lmacloop:
cbz x3, .Lmacout
@@ -861,9 +860,8 @@ AES_FUNC_START(aes_mac_update)
encrypt_block v0, w2, x1, x7, w8
b .Lmacloop

.Lmacout:
st1 {v0.16b}, [x4] /* return dg */
- mov x0, x3
ret
AES_FUNC_END(aes_mac_update)
#endif /* CONFIG_CRYPTO_LIB_AES_CBC_MACS */
diff --git a/lib/crypto/arm64/aes.h b/lib/crypto/arm64/aes.h
index 135d3324a30a..9e9e45a6f787 100644
--- a/lib/crypto/arm64/aes.h
+++ b/lib/crypto/arm64/aes.h
@@ -27,13 +27,13 @@ asmlinkage void __aes_ce_encrypt(const u32 rk[], u8 out[AES_BLOCK_SIZE],
asmlinkage void __aes_ce_decrypt(const u32 inv_rk[], u8 out[AES_BLOCK_SIZE],
const u8 in[AES_BLOCK_SIZE], int rounds);
asmlinkage u32 __aes_ce_sub(u32 l);
asmlinkage void __aes_ce_invert(struct aes_block *out,
const struct aes_block *in);
-asmlinkage size_t neon_aes_mac_update(u8 const in[], u32 const rk[], int rounds,
- size_t blocks, u8 dg[], int enc_before,
- int enc_after);
+asmlinkage void neon_aes_mac_update(u8 const in[], u32 const rk[], int rounds,
+ size_t blocks, u8 dg[], int enc_before,
+ int enc_after);

/*
* Expand an AES key using the crypto extensions if supported and usable or
* generic code otherwise. The expanded key format is compatible between the
* two cases. The outputs are @rndkeys (required) and @inv_rndkeys (optional).
@@ -190,29 +190,20 @@ static bool aes_cbcmac_blocks_arch(u8 h[AES_BLOCK_SIZE],
const struct aes_enckey *key, const u8 *data,
size_t nblocks, bool enc_before,
bool enc_after)
{
if (static_branch_likely(&have_neon) && likely(may_use_simd())) {
- do {
- size_t rem;
-
- scoped_ksimd() {
- if (static_branch_likely(&have_aes))
- rem = ce_aes_mac_update(
- data, key->k.rndkeys,
- key->nrounds, nblocks, h,
- enc_before, enc_after);
- else
- rem = neon_aes_mac_update(
- data, key->k.rndkeys,
- key->nrounds, nblocks, h,
- enc_before, enc_after);
- }
- data += (nblocks - rem) * AES_BLOCK_SIZE;
- nblocks = rem;
- enc_before = false;
- } while (nblocks);
+ scoped_ksimd() {
+ if (static_branch_likely(&have_aes))
+ ce_aes_mac_update(data, key->k.rndkeys,
+ key->nrounds, nblocks, h,
+ enc_before, enc_after);
+ else
+ neon_aes_mac_update(data, key->k.rndkeys,
+ key->nrounds, nblocks, h,
+ enc_before, enc_after);
+ }
return true;
}
return false;
}
#endif /* CONFIG_CRYPTO_LIB_AES_CBC_MACS */
--
2.53.0