kernel_optimize_test/arch/arm64/crypto/sha256-glue.c
Ard Biesheuvel 1a3713c7cd crypto: arm64/sha256-neon - play nice with CONFIG_PREEMPT kernels
Tweak the SHA256 update routines to invoke the SHA256 block transform
block by block, to avoid excessive scheduling delays caused by the
NEON algorithm running with preemption disabled.

Also, remove a stale comment which no longer applies now that kernel
mode NEON is actually disallowed in some contexts.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-03-16 23:35:58 +08:00

197 lines
5.4 KiB
C

/*
* Linux/arm64 port of the OpenSSL SHA256 implementation for AArch64
*
* 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 as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <crypto/sha256_base.h>
#include <linux/cryptohash.h>
#include <linux/types.h>
#include <linux/string.h>
MODULE_DESCRIPTION("SHA-224/SHA-256 secure hash for arm64");
MODULE_AUTHOR("Andy Polyakov <appro@openssl.org>");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("sha224");
MODULE_ALIAS_CRYPTO("sha256");
asmlinkage void sha256_block_data_order(u32 *digest, const void *data,
unsigned int num_blks);
EXPORT_SYMBOL(sha256_block_data_order);
asmlinkage void sha256_block_neon(u32 *digest, const void *data,
unsigned int num_blks);
static int sha256_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
return sha256_base_do_update(desc, data, len,
(sha256_block_fn *)sha256_block_data_order);
}
static int sha256_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
if (len)
sha256_base_do_update(desc, data, len,
(sha256_block_fn *)sha256_block_data_order);
sha256_base_do_finalize(desc,
(sha256_block_fn *)sha256_block_data_order);
return sha256_base_finish(desc, out);
}
static int sha256_final(struct shash_desc *desc, u8 *out)
{
return sha256_finup(desc, NULL, 0, out);
}
static struct shash_alg algs[] = { {
.digestsize = SHA256_DIGEST_SIZE,
.init = sha256_base_init,
.update = sha256_update,
.final = sha256_final,
.finup = sha256_finup,
.descsize = sizeof(struct sha256_state),
.base.cra_name = "sha256",
.base.cra_driver_name = "sha256-arm64",
.base.cra_priority = 100,
.base.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.base.cra_blocksize = SHA256_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
}, {
.digestsize = SHA224_DIGEST_SIZE,
.init = sha224_base_init,
.update = sha256_update,
.final = sha256_final,
.finup = sha256_finup,
.descsize = sizeof(struct sha256_state),
.base.cra_name = "sha224",
.base.cra_driver_name = "sha224-arm64",
.base.cra_priority = 100,
.base.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.base.cra_blocksize = SHA224_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
} };
static int sha256_update_neon(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
if (!may_use_simd())
return sha256_base_do_update(desc, data, len,
(sha256_block_fn *)sha256_block_data_order);
while (len > 0) {
unsigned int chunk = len;
/*
* Don't hog the CPU for the entire time it takes to process all
* input when running on a preemptible kernel, but process the
* data block by block instead.
*/
if (IS_ENABLED(CONFIG_PREEMPT) &&
chunk + sctx->count % SHA256_BLOCK_SIZE > SHA256_BLOCK_SIZE)
chunk = SHA256_BLOCK_SIZE -
sctx->count % SHA256_BLOCK_SIZE;
kernel_neon_begin();
sha256_base_do_update(desc, data, chunk,
(sha256_block_fn *)sha256_block_neon);
kernel_neon_end();
data += chunk;
len -= chunk;
}
return 0;
}
static int sha256_finup_neon(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
if (!may_use_simd()) {
if (len)
sha256_base_do_update(desc, data, len,
(sha256_block_fn *)sha256_block_data_order);
sha256_base_do_finalize(desc,
(sha256_block_fn *)sha256_block_data_order);
} else {
if (len)
sha256_update_neon(desc, data, len);
kernel_neon_begin();
sha256_base_do_finalize(desc,
(sha256_block_fn *)sha256_block_neon);
kernel_neon_end();
}
return sha256_base_finish(desc, out);
}
static int sha256_final_neon(struct shash_desc *desc, u8 *out)
{
return sha256_finup_neon(desc, NULL, 0, out);
}
static struct shash_alg neon_algs[] = { {
.digestsize = SHA256_DIGEST_SIZE,
.init = sha256_base_init,
.update = sha256_update_neon,
.final = sha256_final_neon,
.finup = sha256_finup_neon,
.descsize = sizeof(struct sha256_state),
.base.cra_name = "sha256",
.base.cra_driver_name = "sha256-arm64-neon",
.base.cra_priority = 150,
.base.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.base.cra_blocksize = SHA256_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
}, {
.digestsize = SHA224_DIGEST_SIZE,
.init = sha224_base_init,
.update = sha256_update_neon,
.final = sha256_final_neon,
.finup = sha256_finup_neon,
.descsize = sizeof(struct sha256_state),
.base.cra_name = "sha224",
.base.cra_driver_name = "sha224-arm64-neon",
.base.cra_priority = 150,
.base.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.base.cra_blocksize = SHA224_BLOCK_SIZE,
.base.cra_module = THIS_MODULE,
} };
static int __init sha256_mod_init(void)
{
int ret = crypto_register_shashes(algs, ARRAY_SIZE(algs));
if (ret)
return ret;
if (elf_hwcap & HWCAP_ASIMD) {
ret = crypto_register_shashes(neon_algs, ARRAY_SIZE(neon_algs));
if (ret)
crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
}
return ret;
}
static void __exit sha256_mod_fini(void)
{
if (elf_hwcap & HWCAP_ASIMD)
crypto_unregister_shashes(neon_algs, ARRAY_SIZE(neon_algs));
crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
}
module_init(sha256_mod_init);
module_exit(sha256_mod_fini);