linux/arch/arm/lib/crypto/sha256.c

65 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SHA-256 optimized for ARM
*
* Copyright 2025 Google LLC
*/
#include <asm/neon.h>
#include <crypto/internal/sha2.h>
#include <crypto/internal/simd.h>
#include <linux/kernel.h>
#include <linux/module.h>
asmlinkage void sha256_block_data_order(u32 state[SHA256_STATE_WORDS],
const u8 *data, size_t nblocks);
asmlinkage void sha256_block_data_order_neon(u32 state[SHA256_STATE_WORDS],
const u8 *data, size_t nblocks);
asmlinkage void sha256_ce_transform(u32 state[SHA256_STATE_WORDS],
const u8 *data, size_t nblocks);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);
void sha256_blocks_arch(u32 state[SHA256_STATE_WORDS],
const u8 *data, size_t nblocks)
{
if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
static_branch_likely(&have_neon) && crypto_simd_usable()) {
kernel_neon_begin();
if (static_branch_likely(&have_ce))
sha256_ce_transform(state, data, nblocks);
else
sha256_block_data_order_neon(state, data, nblocks);
kernel_neon_end();
} else {
sha256_block_data_order(state, data, nblocks);
}
}
EXPORT_SYMBOL(sha256_blocks_arch);
bool sha256_is_arch_optimized(void)
{
/* We always can use at least the ARM scalar implementation. */
return true;
}
EXPORT_SYMBOL(sha256_is_arch_optimized);
static int __init sha256_arm_mod_init(void)
{
if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) {
static_branch_enable(&have_neon);
if (elf_hwcap2 & HWCAP2_SHA2)
static_branch_enable(&have_ce);
}
return 0;
}
subsys_initcall(sha256_arm_mod_init);
static void __exit sha256_arm_mod_exit(void)
{
}
module_exit(sha256_arm_mod_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-256 optimized for ARM");