sha256.h

 1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/*
 3 * SHA-256 optimized for ARM
 4 *
 5 * Copyright 2025 Google LLC
 6 */
 7#include <asm/neon.h>
 8#include <asm/simd.h>
 9
10static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
11static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);
12
13asmlinkage void sha256_block_data_order(struct sha256_block_state *state,
14					const u8 *data, size_t nblocks);
15asmlinkage void sha256_block_data_order_neon(struct sha256_block_state *state,
16					     const u8 *data, size_t nblocks);
17asmlinkage void sha256_ce_transform(struct sha256_block_state *state,
18				    const u8 *data, size_t nblocks);
19
20static void sha256_blocks(struct sha256_block_state *state,
21			  const u8 *data, size_t nblocks)
22{
23	if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
24	    static_branch_likely(&have_neon) && likely(may_use_simd())) {
25		scoped_ksimd() {
26			if (static_branch_likely(&have_ce))
27				sha256_ce_transform(state, data, nblocks);
28			else
29				sha256_block_data_order_neon(state, data, nblocks);
30		}
31	} else {
32		sha256_block_data_order(state, data, nblocks);
33	}
34}
35
36#ifdef CONFIG_KERNEL_MODE_NEON
37#define sha256_mod_init_arch sha256_mod_init_arch
38static void sha256_mod_init_arch(void)
39{
40	if (elf_hwcap & HWCAP_NEON) {
41		static_branch_enable(&have_neon);
42		if (elf_hwcap2 & HWCAP2_SHA2)
43			static_branch_enable(&have_ce);
44	}
45}
46#endif /* CONFIG_KERNEL_MODE_NEON */