[PATCH v6 4/6] crypto: arm64/aes-ccm - remove non-SIMD fallback path
From: Ard Biesheuvel <ardb@kernel.org>
Date: 2021-05-26 10:07:44
Also in:
linux-arm-kernel
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
AES/CCM on arm64 is implemented as a synchronous AEAD, and so it is guaranteed by the API that it is only invoked in task or softirq context. Since softirqs are now only handled when the SIMD is not being used in the task context that was interrupted to service the softirq, we no longer need a fallback path. Let's remove it. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm64/crypto/aes-ce-ccm-glue.c | 153 ++++---------------- 1 file changed, 32 insertions(+), 121 deletions(-)
diff --git a/arch/arm64/crypto/aes-ce-ccm-glue.c b/arch/arm64/crypto/aes-ce-ccm-glue.c
index f6d19b0dc893..54bd2494a000 100644
--- a/arch/arm64/crypto/aes-ce-ccm-glue.c
+++ b/arch/arm64/crypto/aes-ce-ccm-glue.c@@ -6,12 +6,10 @@ */ #include <asm/neon.h> -#include <asm/simd.h> #include <asm/unaligned.h> #include <crypto/aes.h> #include <crypto/scatterwalk.h> #include <crypto/internal/aead.h> -#include <crypto/internal/simd.h> #include <crypto/internal/skcipher.h> #include <linux/module.h>
@@ -99,36 +97,10 @@ static int ccm_init_mac(struct aead_request *req, u8 maciv[], u32 msglen) static void ccm_update_mac(struct crypto_aes_ctx *key, u8 mac[], u8 const in[], u32 abytes, u32 *macp) { - if (crypto_simd_usable()) { - kernel_neon_begin(); - ce_aes_ccm_auth_data(mac, in, abytes, macp, key->key_enc, - num_rounds(key)); - kernel_neon_end(); - } else { - if (*macp > 0 && *macp < AES_BLOCK_SIZE) { - int added = min(abytes, AES_BLOCK_SIZE - *macp); - - crypto_xor(&mac[*macp], in, added); - - *macp += added; - in += added; - abytes -= added; - } - - while (abytes >= AES_BLOCK_SIZE) { - aes_encrypt(key, mac, mac); - crypto_xor(mac, in, AES_BLOCK_SIZE); - - in += AES_BLOCK_SIZE; - abytes -= AES_BLOCK_SIZE; - } - - if (abytes > 0) { - aes_encrypt(key, mac, mac); - crypto_xor(mac, in, abytes); - *macp = abytes; - } - } + kernel_neon_begin(); + ce_aes_ccm_auth_data(mac, in, abytes, macp, key->key_enc, + num_rounds(key)); + kernel_neon_end(); } static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[])
@@ -171,54 +143,6 @@ static void ccm_calculate_auth_mac(struct aead_request *req, u8 mac[]) } while (len); } -static int ccm_crypt_fallback(struct skcipher_walk *walk, u8 mac[], u8 iv0[], - struct crypto_aes_ctx *ctx, bool enc) -{ - u8 buf[AES_BLOCK_SIZE]; - int err = 0; - - while (walk->nbytes) { - int blocks = walk->nbytes / AES_BLOCK_SIZE; - u32 tail = walk->nbytes % AES_BLOCK_SIZE; - u8 *dst = walk->dst.virt.addr; - u8 *src = walk->src.virt.addr; - u32 nbytes = walk->nbytes; - - if (nbytes == walk->total && tail > 0) { - blocks++; - tail = 0; - } - - do { - u32 bsize = AES_BLOCK_SIZE; - - if (nbytes < AES_BLOCK_SIZE) - bsize = nbytes; - - crypto_inc(walk->iv, AES_BLOCK_SIZE); - aes_encrypt(ctx, buf, walk->iv); - aes_encrypt(ctx, mac, mac); - if (enc) - crypto_xor(mac, src, bsize); - crypto_xor_cpy(dst, src, buf, bsize); - if (!enc) - crypto_xor(mac, dst, bsize); - dst += bsize; - src += bsize; - nbytes -= bsize; - } while (--blocks); - - err = skcipher_walk_done(walk, tail); - } - - if (!err) { - aes_encrypt(ctx, buf, iv0); - aes_encrypt(ctx, mac, mac); - crypto_xor(mac, buf, AES_BLOCK_SIZE); - } - return err; -} - static int ccm_encrypt(struct aead_request *req) { struct crypto_aead *aead = crypto_aead_reqtfm(req);
@@ -241,30 +165,24 @@ static int ccm_encrypt(struct aead_request *req) err = skcipher_walk_aead_encrypt(&walk, req, false); - if (crypto_simd_usable()) { - while (walk.nbytes) { - u32 tail = walk.nbytes % AES_BLOCK_SIZE; + while (walk.nbytes) { + u32 tail = walk.nbytes % AES_BLOCK_SIZE; - if (walk.nbytes == walk.total) - tail = 0; + if (walk.nbytes == walk.total) + tail = 0; - kernel_neon_begin(); - ce_aes_ccm_encrypt(walk.dst.virt.addr, - walk.src.virt.addr, - walk.nbytes - tail, ctx->key_enc, - num_rounds(ctx), mac, walk.iv); - kernel_neon_end(); + kernel_neon_begin(); + ce_aes_ccm_encrypt(walk.dst.virt.addr, walk.src.virt.addr, + walk.nbytes - tail, ctx->key_enc, + num_rounds(ctx), mac, walk.iv); + kernel_neon_end(); - err = skcipher_walk_done(&walk, tail); - } - if (!err) { - kernel_neon_begin(); - ce_aes_ccm_final(mac, buf, ctx->key_enc, - num_rounds(ctx)); - kernel_neon_end(); - } - } else { - err = ccm_crypt_fallback(&walk, mac, buf, ctx, true); + err = skcipher_walk_done(&walk, tail); + } + if (!err) { + kernel_neon_begin(); + ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx)); + kernel_neon_end(); } if (err) return err;
@@ -299,32 +217,25 @@ static int ccm_decrypt(struct aead_request *req) err = skcipher_walk_aead_decrypt(&walk, req, false); - if (crypto_simd_usable()) { - while (walk.nbytes) { - u32 tail = walk.nbytes % AES_BLOCK_SIZE; + while (walk.nbytes) { + u32 tail = walk.nbytes % AES_BLOCK_SIZE; - if (walk.nbytes == walk.total) - tail = 0; + if (walk.nbytes == walk.total) + tail = 0; - kernel_neon_begin(); - ce_aes_ccm_decrypt(walk.dst.virt.addr, - walk.src.virt.addr, + kernel_neon_begin(); + ce_aes_ccm_decrypt(walk.dst.virt.addr, walk.src.virt.addr, walk.nbytes - tail, ctx->key_enc, num_rounds(ctx), mac, walk.iv); - kernel_neon_end(); + kernel_neon_end(); - err = skcipher_walk_done(&walk, tail); - } - if (!err) { - kernel_neon_begin(); - ce_aes_ccm_final(mac, buf, ctx->key_enc, - num_rounds(ctx)); - kernel_neon_end(); - } - } else { - err = ccm_crypt_fallback(&walk, mac, buf, ctx, false); + err = skcipher_walk_done(&walk, tail); + } + if (!err) { + kernel_neon_begin(); + ce_aes_ccm_final(mac, buf, ctx->key_enc, num_rounds(ctx)); + kernel_neon_end(); } - if (err) return err;
--
2.20.1