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author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-12-08 14:28:59 +0000 |
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committer | Herbert Xu <herbert@gondor.apana.org.au> | 2016-12-27 17:47:29 +0800 |
commit | 8096667273477e735b0072b11a6d617ccee45e5f (patch) | |
tree | f29612ebcdc4b8bb4d50d2b0c32edcb64e608e4b /arch/arm/crypto/chacha20-neon-glue.c | |
parent | 8621caa0d45e731f2e9f5889ff5bb384fcd6e059 (diff) | |
download | linux-stable-8096667273477e735b0072b11a6d617ccee45e5f.tar.gz linux-stable-8096667273477e735b0072b11a6d617ccee45e5f.tar.bz2 linux-stable-8096667273477e735b0072b11a6d617ccee45e5f.zip |
crypto: arm/chacha20 - implement NEON version based on SSE3 code
This is a straight port to ARM/NEON of the x86 SSE3 implementation
of the ChaCha20 stream cipher.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm/crypto/chacha20-neon-glue.c')
-rw-r--r-- | arch/arm/crypto/chacha20-neon-glue.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/arm/crypto/chacha20-neon-glue.c b/arch/arm/crypto/chacha20-neon-glue.c new file mode 100644 index 000000000000..554f7f6069da --- /dev/null +++ b/arch/arm/crypto/chacha20-neon-glue.c @@ -0,0 +1,136 @@ +/* + * ChaCha20 256-bit cipher algorithm, RFC7539, ARM NEON functions + * + * Copyright (C) 2016 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. + * + * Based on: + * ChaCha20 256-bit cipher algorithm, RFC7539, SIMD glue code + * + * Copyright (C) 2015 Martin Willi + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <crypto/algapi.h> +#include <crypto/chacha20.h> +#include <linux/crypto.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#include <asm/hwcap.h> +#include <asm/neon.h> +#include <asm/simd.h> + +asmlinkage void chacha20_block_xor_neon(u32 *state, u8 *dst, const u8 *src); +asmlinkage void chacha20_4block_xor_neon(u32 *state, u8 *dst, const u8 *src); + +static void chacha20_dosimd(u32 *state, u8 *dst, const u8 *src, + unsigned int bytes) +{ + u8 buf[CHACHA20_BLOCK_SIZE]; + + while (bytes >= CHACHA20_BLOCK_SIZE * 4) { + chacha20_4block_xor_neon(state, dst, src); + bytes -= CHACHA20_BLOCK_SIZE * 4; + src += CHACHA20_BLOCK_SIZE * 4; + dst += CHACHA20_BLOCK_SIZE * 4; + state[12] += 4; + } + while (bytes >= CHACHA20_BLOCK_SIZE) { + chacha20_block_xor_neon(state, dst, src); + bytes -= CHACHA20_BLOCK_SIZE; + src += CHACHA20_BLOCK_SIZE; + dst += CHACHA20_BLOCK_SIZE; + state[12]++; + } + if (bytes) { + memcpy(buf, src, bytes); + chacha20_block_xor_neon(state, buf, buf); + memcpy(dst, buf, bytes); + } +} + +static int chacha20_simd(struct blkcipher_desc *desc, struct scatterlist *dst, + struct scatterlist *src, unsigned int nbytes) +{ + struct blkcipher_walk walk; + u32 state[16]; + int err; + + if (nbytes <= CHACHA20_BLOCK_SIZE || !may_use_simd()) + return crypto_chacha20_crypt(desc, dst, src, nbytes); + + blkcipher_walk_init(&walk, dst, src, nbytes); + err = blkcipher_walk_virt_block(desc, &walk, CHACHA20_BLOCK_SIZE); + + crypto_chacha20_init(state, crypto_blkcipher_ctx(desc->tfm), walk.iv); + + kernel_neon_begin(); + + while (walk.nbytes >= CHACHA20_BLOCK_SIZE) { + chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr, + rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE)); + err = blkcipher_walk_done(desc, &walk, + walk.nbytes % CHACHA20_BLOCK_SIZE); + } + + if (walk.nbytes) { + chacha20_dosimd(state, walk.dst.virt.addr, walk.src.virt.addr, + walk.nbytes); + err = blkcipher_walk_done(desc, &walk, 0); + } + + kernel_neon_end(); + + return err; +} + +static struct crypto_alg alg = { + .cra_name = "chacha20", + .cra_driver_name = "chacha20-neon", + .cra_priority = 300, + .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, + .cra_blocksize = 1, + .cra_type = &crypto_blkcipher_type, + .cra_ctxsize = sizeof(struct chacha20_ctx), + .cra_alignmask = sizeof(u32) - 1, + .cra_module = THIS_MODULE, + .cra_u = { + .blkcipher = { + .min_keysize = CHACHA20_KEY_SIZE, + .max_keysize = CHACHA20_KEY_SIZE, + .ivsize = CHACHA20_IV_SIZE, + .geniv = "seqiv", + .setkey = crypto_chacha20_setkey, + .encrypt = chacha20_simd, + .decrypt = chacha20_simd, + }, + }, +}; + +static int __init chacha20_simd_mod_init(void) +{ + if (!(elf_hwcap & HWCAP_NEON)) + return -ENODEV; + + return crypto_register_alg(&alg); +} + +static void __exit chacha20_simd_mod_fini(void) +{ + crypto_unregister_alg(&alg); +} + +module_init(chacha20_simd_mod_init); +module_exit(chacha20_simd_mod_fini); + +MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS_CRYPTO("chacha20"); |