1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * SHA-256 optimized for ARM64
4 *
5 * Copyright 2025 Google LLC
6 */
7 #include <asm/neon.h>
8 #include <crypto/internal/simd.h>
9 #include <linux/cpufeature.h>
10
11 asmlinkage void sha256_block_data_order(struct sha256_block_state *state,
12 const u8 *data, size_t nblocks);
13 asmlinkage void sha256_block_neon(struct sha256_block_state *state,
14 const u8 *data, size_t nblocks);
15 asmlinkage size_t __sha256_ce_transform(struct sha256_block_state *state,
16 const u8 *data, size_t nblocks);
17
18 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
19 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce);
20
sha256_blocks(struct sha256_block_state * state,const u8 * data,size_t nblocks)21 static void sha256_blocks(struct sha256_block_state *state,
22 const u8 *data, size_t nblocks)
23 {
24 if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
25 static_branch_likely(&have_neon) && crypto_simd_usable()) {
26 if (static_branch_likely(&have_ce)) {
27 do {
28 size_t rem;
29
30 kernel_neon_begin();
31 rem = __sha256_ce_transform(state,
32 data, nblocks);
33 kernel_neon_end();
34 data += (nblocks - rem) * SHA256_BLOCK_SIZE;
35 nblocks = rem;
36 } while (nblocks);
37 } else {
38 kernel_neon_begin();
39 sha256_block_neon(state, data, nblocks);
40 kernel_neon_end();
41 }
42 } else {
43 sha256_block_data_order(state, data, nblocks);
44 }
45 }
46
47 #ifdef CONFIG_KERNEL_MODE_NEON
48 #define sha256_mod_init_arch sha256_mod_init_arch
sha256_mod_init_arch(void)49 static inline void sha256_mod_init_arch(void)
50 {
51 if (cpu_have_named_feature(ASIMD)) {
52 static_branch_enable(&have_neon);
53 if (cpu_have_named_feature(SHA2))
54 static_branch_enable(&have_ce);
55 }
56 }
57 #endif /* CONFIG_KERNEL_MODE_NEON */
58