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 <crypto/internal/sha2.h> 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 12 asmlinkage void sha256_blocks_arch(u32 state[SHA256_STATE_WORDS], 13 const u8 *data, size_t nblocks); 14 EXPORT_SYMBOL_GPL(sha256_blocks_arch); 15 asmlinkage void sha256_block_data_order_neon(u32 state[SHA256_STATE_WORDS], 16 const u8 *data, size_t nblocks); 17 asmlinkage void sha256_ce_transform(u32 state[SHA256_STATE_WORDS], 18 const u8 *data, size_t nblocks); 19 20 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); 21 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_ce); 22 23 void sha256_blocks_simd(u32 state[SHA256_STATE_WORDS], 24 const u8 *data, size_t nblocks) 25 { 26 if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && 27 static_branch_likely(&have_neon)) { 28 kernel_neon_begin(); 29 if (static_branch_likely(&have_ce)) 30 sha256_ce_transform(state, data, nblocks); 31 else 32 sha256_block_data_order_neon(state, data, nblocks); 33 kernel_neon_end(); 34 } else { 35 sha256_blocks_arch(state, data, nblocks); 36 } 37 } 38 EXPORT_SYMBOL_GPL(sha256_blocks_simd); 39 40 bool sha256_is_arch_optimized(void) 41 { 42 /* We always can use at least the ARM scalar implementation. */ 43 return true; 44 } 45 EXPORT_SYMBOL_GPL(sha256_is_arch_optimized); 46 47 static int __init sha256_arm_mod_init(void) 48 { 49 if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) { 50 static_branch_enable(&have_neon); 51 if (elf_hwcap2 & HWCAP2_SHA2) 52 static_branch_enable(&have_ce); 53 } 54 return 0; 55 } 56 subsys_initcall(sha256_arm_mod_init); 57 58 static void __exit sha256_arm_mod_exit(void) 59 { 60 } 61 module_exit(sha256_arm_mod_exit); 62 63 MODULE_LICENSE("GPL"); 64 MODULE_DESCRIPTION("SHA-256 optimized for ARM"); 65