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f53d18a4e6
Before modifying the prototypes of kernel_neon_begin() and kernel_neon_end() to accommodate kernel mode FP/SIMD state buffers allocated on the stack, move arm64 to the new 'ksimd' scoped guard API, which encapsulates the calls to those functions. For symmetry, do the same for 32-bit ARM too. Reviewed-by: Eric Biggers <ebiggers@kernel.org> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
92 lines
2.8 KiB
C
92 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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* SHA-256 optimized for ARM64
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*
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* Copyright 2025 Google LLC
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*/
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#include <asm/simd.h>
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#include <linux/cpufeature.h>
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
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static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);
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asmlinkage void sha256_block_data_order(struct sha256_block_state *state,
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const u8 *data, size_t nblocks);
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asmlinkage void sha256_block_neon(struct sha256_block_state *state,
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const u8 *data, size_t nblocks);
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asmlinkage size_t __sha256_ce_transform(struct sha256_block_state *state,
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const u8 *data, size_t nblocks);
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static void sha256_blocks(struct sha256_block_state *state,
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const u8 *data, size_t nblocks)
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{
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if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
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static_branch_likely(&have_neon) && likely(may_use_simd())) {
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if (static_branch_likely(&have_ce)) {
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do {
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size_t rem;
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scoped_ksimd()
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rem = __sha256_ce_transform(state, data,
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nblocks);
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data += (nblocks - rem) * SHA256_BLOCK_SIZE;
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nblocks = rem;
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} while (nblocks);
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} else {
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scoped_ksimd()
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sha256_block_neon(state, data, nblocks);
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}
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} else {
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sha256_block_data_order(state, data, nblocks);
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}
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}
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static_assert(offsetof(struct __sha256_ctx, state) == 0);
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static_assert(offsetof(struct __sha256_ctx, bytecount) == 32);
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static_assert(offsetof(struct __sha256_ctx, buf) == 40);
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asmlinkage void sha256_ce_finup2x(const struct __sha256_ctx *ctx,
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const u8 *data1, const u8 *data2, int len,
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u8 out1[SHA256_DIGEST_SIZE],
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u8 out2[SHA256_DIGEST_SIZE]);
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#define sha256_finup_2x_arch sha256_finup_2x_arch
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static bool sha256_finup_2x_arch(const struct __sha256_ctx *ctx,
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const u8 *data1, const u8 *data2, size_t len,
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u8 out1[SHA256_DIGEST_SIZE],
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u8 out2[SHA256_DIGEST_SIZE])
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{
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/*
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* The assembly requires len >= SHA256_BLOCK_SIZE && len <= INT_MAX.
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* Further limit len to 65536 to avoid spending too long with preemption
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* disabled. (Of course, in practice len is nearly always 4096 anyway.)
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*/
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if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
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static_branch_likely(&have_ce) && len >= SHA256_BLOCK_SIZE &&
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len <= 65536 && likely(may_use_simd())) {
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scoped_ksimd()
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sha256_ce_finup2x(ctx, data1, data2, len, out1, out2);
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kmsan_unpoison_memory(out1, SHA256_DIGEST_SIZE);
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kmsan_unpoison_memory(out2, SHA256_DIGEST_SIZE);
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return true;
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}
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return false;
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}
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static bool sha256_finup_2x_is_optimized_arch(void)
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{
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return static_key_enabled(&have_ce);
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}
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#ifdef CONFIG_KERNEL_MODE_NEON
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#define sha256_mod_init_arch sha256_mod_init_arch
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static void sha256_mod_init_arch(void)
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{
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if (cpu_have_named_feature(ASIMD)) {
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static_branch_enable(&have_neon);
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if (cpu_have_named_feature(SHA2))
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static_branch_enable(&have_ce);
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}
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}
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#endif /* CONFIG_KERNEL_MODE_NEON */
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