diff options
author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2017-01-11 16:41:52 +0000 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2017-01-13 00:26:49 +0800 |
commit | bed593c0e852f5c1efd3ca4e984fd744c51cf6ee (patch) | |
tree | c3ef5fd3b1f202288c63d037f1b0bf62ea26fd4f /arch/arm64/crypto/aes-cipher-glue.c | |
parent | 293614ce3eda94a3c9b38d5c18fdc06eb1397221 (diff) |
crypto: arm64/aes - add scalar implementation
This adds a scalar implementation of AES, based on the precomputed tables
that are exposed by the generic AES code. Since rotates are cheap on arm64,
this implementation only uses the 4 core tables (of 1 KB each), and avoids
the prerotated ones, reducing the D-cache footprint by 75%.
On Cortex-A57, this code manages 13.0 cycles per byte, which is ~34% faster
than the generic C code. (Note that this is still >13x slower than the code
that uses the optional ARMv8 Crypto Extensions, which manages <1 cycles per
byte.)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm64/crypto/aes-cipher-glue.c')
-rw-r--r-- | arch/arm64/crypto/aes-cipher-glue.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/arch/arm64/crypto/aes-cipher-glue.c b/arch/arm64/crypto/aes-cipher-glue.c new file mode 100644 index 000000000000..7288e7cbebff --- /dev/null +++ b/arch/arm64/crypto/aes-cipher-glue.c @@ -0,0 +1,69 @@ +/* + * Scalar AES core transform + * + * Copyright (C) 2017 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 by the Free Software Foundation. + */ + +#include <crypto/aes.h> +#include <linux/crypto.h> +#include <linux/module.h> + +asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); +EXPORT_SYMBOL(__aes_arm64_encrypt); + +asmlinkage void __aes_arm64_decrypt(u32 *rk, u8 *out, const u8 *in, int rounds); +EXPORT_SYMBOL(__aes_arm64_decrypt); + +static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ + struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); + int rounds = 6 + ctx->key_length / 4; + + __aes_arm64_encrypt(ctx->key_enc, out, in, rounds); +} + +static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) +{ + struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm); + int rounds = 6 + ctx->key_length / 4; + + __aes_arm64_decrypt(ctx->key_dec, out, in, rounds); +} + +static struct crypto_alg aes_alg = { + .cra_name = "aes", + .cra_driver_name = "aes-arm64", + .cra_priority = 200, + .cra_flags = CRYPTO_ALG_TYPE_CIPHER, + .cra_blocksize = AES_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct crypto_aes_ctx), + .cra_module = THIS_MODULE, + + .cra_cipher.cia_min_keysize = AES_MIN_KEY_SIZE, + .cra_cipher.cia_max_keysize = AES_MAX_KEY_SIZE, + .cra_cipher.cia_setkey = crypto_aes_set_key, + .cra_cipher.cia_encrypt = aes_encrypt, + .cra_cipher.cia_decrypt = aes_decrypt +}; + +static int __init aes_init(void) +{ + return crypto_register_alg(&aes_alg); +} + +static void __exit aes_fini(void) +{ + crypto_unregister_alg(&aes_alg); +} + +module_init(aes_init); +module_exit(aes_fini); + +MODULE_DESCRIPTION("Scalar AES cipher for arm64"); +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_CRYPTO("aes"); |