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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2018-07-30 23:06:42 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2018-08-07 17:38:04 +0800
commit30f1a9f53e77e4c9ddf55ebfda8a9d7666e46964 (patch)
tree6696057d0c4cb95671a65cad2df8f9b573a0ed6d /arch
parente0bd888dc487e0c444ee5f3bf55020862d16a225 (diff)
downloadlinux-30f1a9f53e77e4c9ddf55ebfda8a9d7666e46964.tar.bz2
crypto: arm64/aes-ce-gcm - don't reload key schedule if avoidable
Squeeze out another 5% of performance by minimizing the number of invocations of kernel_neon_begin()/kernel_neon_end() on the common path, which also allows some reloads of the key schedule to be optimized away. The resulting code runs at 2.3 cycles per byte on a Cortex-A53. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/crypto/ghash-ce-core.S9
-rw-r--r--arch/arm64/crypto/ghash-ce-glue.c81
2 files changed, 49 insertions, 41 deletions
diff --git a/arch/arm64/crypto/ghash-ce-core.S b/arch/arm64/crypto/ghash-ce-core.S
index f7281e7a592f..913e49932ae6 100644
--- a/arch/arm64/crypto/ghash-ce-core.S
+++ b/arch/arm64/crypto/ghash-ce-core.S
@@ -1,7 +1,7 @@
/*
* Accelerated GHASH implementation with ARMv8 PMULL instructions.
*
- * Copyright (C) 2014 - 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
@@ -332,8 +332,6 @@ ENDPROC(pmull_ghash_update_p8)
ld1 {XL.2d}, [x1]
ldr x8, [x5, #8] // load lower counter
- load_round_keys w7, x6
-
movi MASK.16b, #0xe1
trn1 SHASH2.2d, SHASH.2d, HH.2d
trn2 T1.2d, SHASH.2d, HH.2d
@@ -346,6 +344,8 @@ CPU_LE( rev x8, x8 )
ld1 {KS0.16b-KS1.16b}, [x10]
.endif
+ cbnz x6, 4f
+
0: ld1 {INP0.16b-INP1.16b}, [x3], #32
rev x9, x8
@@ -471,6 +471,9 @@ CPU_LE( rev x8, x8 )
enc_round KS0, v20
enc_round KS1, v20
b 1b
+
+4: load_round_keys w7, x6
+ b 0b
.endm
/*
diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
index cd91b146c87d..42a0e84e276c 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -1,7 +1,7 @@
/*
* Accelerated GHASH implementation with ARMv8 PMULL instructions.
*
- * Copyright (C) 2014 - 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
+ * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
@@ -373,37 +373,39 @@ static int gcm_encrypt(struct aead_request *req)
memcpy(iv, req->iv, GCM_IV_SIZE);
put_unaligned_be32(1, iv + GCM_IV_SIZE);
- if (likely(may_use_simd())) {
- kernel_neon_begin();
+ err = skcipher_walk_aead_encrypt(&walk, req, false);
+ if (likely(may_use_simd() && walk.total >= 2 * AES_BLOCK_SIZE)) {
+ u32 const *rk = NULL;
+
+ kernel_neon_begin();
pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds);
put_unaligned_be32(2, iv + GCM_IV_SIZE);
pmull_gcm_encrypt_block(ks, iv, NULL, nrounds);
put_unaligned_be32(3, iv + GCM_IV_SIZE);
pmull_gcm_encrypt_block(ks + AES_BLOCK_SIZE, iv, NULL, nrounds);
put_unaligned_be32(4, iv + GCM_IV_SIZE);
- kernel_neon_end();
-
- err = skcipher_walk_aead_encrypt(&walk, req, false);
- while (walk.nbytes >= 2 * AES_BLOCK_SIZE) {
+ do {
int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2;
- kernel_neon_begin();
+ if (rk)
+ kernel_neon_begin();
+
pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr,
walk.src.virt.addr, ctx->h2, iv,
- ctx->aes_key.key_enc, nrounds, ks);
+ rk, nrounds, ks);
kernel_neon_end();
err = skcipher_walk_done(&walk,
walk.nbytes % (2 * AES_BLOCK_SIZE));
- }
+
+ rk = ctx->aes_key.key_enc;
+ } while (walk.nbytes >= 2 * AES_BLOCK_SIZE);
} else {
__aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds);
put_unaligned_be32(2, iv + GCM_IV_SIZE);
- err = skcipher_walk_aead_encrypt(&walk, req, false);
-
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = walk.nbytes / AES_BLOCK_SIZE;
u8 *dst = walk.dst.virt.addr;
@@ -485,50 +487,53 @@ static int gcm_decrypt(struct aead_request *req)
memcpy(iv, req->iv, GCM_IV_SIZE);
put_unaligned_be32(1, iv + GCM_IV_SIZE);
- if (likely(may_use_simd())) {
+ err = skcipher_walk_aead_decrypt(&walk, req, false);
+
+ if (likely(may_use_simd() && walk.total >= 2 * AES_BLOCK_SIZE)) {
+ u32 const *rk = NULL;
+
kernel_neon_begin();
pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds);
put_unaligned_be32(2, iv + GCM_IV_SIZE);
- kernel_neon_end();
- err = skcipher_walk_aead_decrypt(&walk, req, false);
-
- while (walk.nbytes >= 2 * AES_BLOCK_SIZE) {
+ do {
int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2;
+ int rem = walk.total - blocks * AES_BLOCK_SIZE;
+
+ if (rk)
+ kernel_neon_begin();
- kernel_neon_begin();
pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr,
walk.src.virt.addr, ctx->h2, iv,
- ctx->aes_key.key_enc, nrounds);
- kernel_neon_end();
+ rk, nrounds);
- err = skcipher_walk_done(&walk,
- walk.nbytes % (2 * AES_BLOCK_SIZE));
- }
+ /* check if this is the final iteration of the loop */
+ if (rem < (2 * AES_BLOCK_SIZE)) {
+ u8 *iv2 = iv + AES_BLOCK_SIZE;
- if (walk.nbytes) {
- u8 *iv2 = iv + AES_BLOCK_SIZE;
+ if (rem > AES_BLOCK_SIZE) {
+ memcpy(iv2, iv, AES_BLOCK_SIZE);
+ crypto_inc(iv2, AES_BLOCK_SIZE);
+ }
- if (walk.nbytes > AES_BLOCK_SIZE) {
- memcpy(iv2, iv, AES_BLOCK_SIZE);
- crypto_inc(iv2, AES_BLOCK_SIZE);
- }
+ pmull_gcm_encrypt_block(iv, iv, NULL, nrounds);
- kernel_neon_begin();
- pmull_gcm_encrypt_block(iv, iv, ctx->aes_key.key_enc,
- nrounds);
+ if (rem > AES_BLOCK_SIZE)
+ pmull_gcm_encrypt_block(iv2, iv2, NULL,
+ nrounds);
+ }
- if (walk.nbytes > AES_BLOCK_SIZE)
- pmull_gcm_encrypt_block(iv2, iv2, NULL,
- nrounds);
kernel_neon_end();
- }
+
+ err = skcipher_walk_done(&walk,
+ walk.nbytes % (2 * AES_BLOCK_SIZE));
+
+ rk = ctx->aes_key.key_enc;
+ } while (walk.nbytes >= 2 * AES_BLOCK_SIZE);
} else {
__aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds);
put_unaligned_be32(2, iv + GCM_IV_SIZE);
- err = skcipher_walk_aead_decrypt(&walk, req, false);
-
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = walk.nbytes / AES_BLOCK_SIZE;
u8 *dst = walk.dst.virt.addr;