linux/arch/arm64/crypto/sha1-ce-glue.c
Ard Biesheuvel 0771f3234d crypto: arm64/sha1-ce - add non-SIMD generic fallback
The arm64 kernel will shortly disallow nested kernel mode NEON, so
add a fallback to scalar C code that can be invoked in that case.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-08-04 09:27:18 +08:00

120 lines
3.1 KiB
C

/*
* sha1-ce-glue.c - SHA-1 secure hash using ARMv8 Crypto Extensions
*
* Copyright (C) 2014 - 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 <asm/neon.h>
#include <asm/simd.h>
#include <asm/unaligned.h>
#include <crypto/internal/hash.h>
#include <crypto/sha.h>
#include <crypto/sha1_base.h>
#include <linux/cpufeature.h>
#include <linux/crypto.h>
#include <linux/module.h>
MODULE_DESCRIPTION("SHA1 secure hash using ARMv8 Crypto Extensions");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
struct sha1_ce_state {
struct sha1_state sst;
u32 finalize;
};
asmlinkage void sha1_ce_transform(struct sha1_ce_state *sst, u8 const *src,
int blocks);
const u32 sha1_ce_offsetof_count = offsetof(struct sha1_ce_state, sst.count);
const u32 sha1_ce_offsetof_finalize = offsetof(struct sha1_ce_state, finalize);
static int sha1_ce_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha1_ce_state *sctx = shash_desc_ctx(desc);
if (!may_use_simd())
return crypto_sha1_update(desc, data, len);
sctx->finalize = 0;
kernel_neon_begin();
sha1_base_do_update(desc, data, len,
(sha1_block_fn *)sha1_ce_transform);
kernel_neon_end();
return 0;
}
static int sha1_ce_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
struct sha1_ce_state *sctx = shash_desc_ctx(desc);
bool finalize = !sctx->sst.count && !(len % SHA1_BLOCK_SIZE);
if (!may_use_simd())
return crypto_sha1_finup(desc, data, len, out);
/*
* Allow the asm code to perform the finalization if there is no
* partial data and the input is a round multiple of the block size.
*/
sctx->finalize = finalize;
kernel_neon_begin();
sha1_base_do_update(desc, data, len,
(sha1_block_fn *)sha1_ce_transform);
if (!finalize)
sha1_base_do_finalize(desc, (sha1_block_fn *)sha1_ce_transform);
kernel_neon_end();
return sha1_base_finish(desc, out);
}
static int sha1_ce_final(struct shash_desc *desc, u8 *out)
{
struct sha1_ce_state *sctx = shash_desc_ctx(desc);
if (!may_use_simd())
return crypto_sha1_finup(desc, NULL, 0, out);
sctx->finalize = 0;
kernel_neon_begin();
sha1_base_do_finalize(desc, (sha1_block_fn *)sha1_ce_transform);
kernel_neon_end();
return sha1_base_finish(desc, out);
}
static struct shash_alg alg = {
.init = sha1_base_init,
.update = sha1_ce_update,
.final = sha1_ce_final,
.finup = sha1_ce_finup,
.descsize = sizeof(struct sha1_ce_state),
.digestsize = SHA1_DIGEST_SIZE,
.base = {
.cra_name = "sha1",
.cra_driver_name = "sha1-ce",
.cra_priority = 200,
.cra_flags = CRYPTO_ALG_TYPE_SHASH,
.cra_blocksize = SHA1_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
};
static int __init sha1_ce_mod_init(void)
{
return crypto_register_shash(&alg);
}
static void __exit sha1_ce_mod_fini(void)
{
crypto_unregister_shash(&alg);
}
module_cpu_feature_match(SHA1, sha1_ce_mod_init);
module_exit(sha1_ce_mod_fini);