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/simd.h> 8 #include <linux/cpufeature.h> 9 10 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); 11 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce); 12 13 asmlinkage void sha256_block_data_order(struct sha256_block_state *state, 14 const u8 *data, size_t nblocks); 15 asmlinkage void sha256_block_neon(struct sha256_block_state *state, 16 const u8 *data, size_t nblocks); 17 asmlinkage void sha256_ce_transform(struct sha256_block_state *state, 18 const u8 *data, size_t nblocks); 19 20 static void sha256_blocks(struct sha256_block_state *state, 21 const u8 *data, size_t nblocks) 22 { 23 if (static_branch_likely(&have_neon) && likely(may_use_simd())) { 24 scoped_ksimd() { 25 if (static_branch_likely(&have_ce)) 26 sha256_ce_transform(state, data, nblocks); 27 else 28 sha256_block_neon(state, data, nblocks); 29 } 30 } else { 31 sha256_block_data_order(state, data, nblocks); 32 } 33 } 34 35 static_assert(offsetof(struct __sha256_ctx, state) == 0); 36 static_assert(offsetof(struct __sha256_ctx, bytecount) == 32); 37 static_assert(offsetof(struct __sha256_ctx, buf) == 40); 38 asmlinkage void sha256_ce_finup2x(const struct __sha256_ctx *ctx, 39 const u8 *data1, const u8 *data2, int len, 40 u8 out1[SHA256_DIGEST_SIZE], 41 u8 out2[SHA256_DIGEST_SIZE]); 42 43 #define sha256_finup_2x_arch sha256_finup_2x_arch 44 static bool sha256_finup_2x_arch(const struct __sha256_ctx *ctx, 45 const u8 *data1, const u8 *data2, size_t len, 46 u8 out1[SHA256_DIGEST_SIZE], 47 u8 out2[SHA256_DIGEST_SIZE]) 48 { 49 /* The assembly requires len >= SHA256_BLOCK_SIZE && len <= INT_MAX. */ 50 if (static_branch_likely(&have_ce) && len >= SHA256_BLOCK_SIZE && 51 len <= INT_MAX && likely(may_use_simd())) { 52 scoped_ksimd() 53 sha256_ce_finup2x(ctx, data1, data2, len, out1, out2); 54 kmsan_unpoison_memory(out1, SHA256_DIGEST_SIZE); 55 kmsan_unpoison_memory(out2, SHA256_DIGEST_SIZE); 56 return true; 57 } 58 return false; 59 } 60 61 static bool sha256_finup_2x_is_optimized_arch(void) 62 { 63 return static_key_enabled(&have_ce); 64 } 65 66 #define sha256_mod_init_arch sha256_mod_init_arch 67 static void sha256_mod_init_arch(void) 68 { 69 if (cpu_have_named_feature(ASIMD)) { 70 static_branch_enable(&have_neon); 71 if (cpu_have_named_feature(SHA2)) 72 static_branch_enable(&have_ce); 73 } 74 } 75