1 // SPDX-License-Identifier: GPL-2.0 OR MIT 2 /* 3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. 4 * 5 * Based on public domain code from Daniel J. Bernstein and Peter Schwabe. This 6 * began from SUPERCOP's curve25519/neon2/scalarmult.s, but has subsequently been 7 * manually reworked for use in kernel space. 8 */ 9 10 #include <asm/hwcap.h> 11 #include <asm/neon.h> 12 #include <asm/simd.h> 13 #include <crypto/internal/simd.h> 14 #include <linux/types.h> 15 #include <linux/jump_label.h> 16 17 asmlinkage void curve25519_neon(u8 mypublic[CURVE25519_KEY_SIZE], 18 const u8 secret[CURVE25519_KEY_SIZE], 19 const u8 basepoint[CURVE25519_KEY_SIZE]); 20 21 static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); 22 23 static void curve25519_arch(u8 out[CURVE25519_KEY_SIZE], 24 const u8 scalar[CURVE25519_KEY_SIZE], 25 const u8 point[CURVE25519_KEY_SIZE]) 26 { 27 if (static_branch_likely(&have_neon) && crypto_simd_usable()) { 28 kernel_neon_begin(); 29 curve25519_neon(out, scalar, point); 30 kernel_neon_end(); 31 } else { 32 curve25519_generic(out, scalar, point); 33 } 34 } 35 36 static void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE], 37 const u8 secret[CURVE25519_KEY_SIZE]) 38 { 39 curve25519_arch(pub, secret, curve25519_base_point); 40 } 41 42 #define curve25519_mod_init_arch curve25519_mod_init_arch 43 static void curve25519_mod_init_arch(void) 44 { 45 if (elf_hwcap & HWCAP_NEON) 46 static_branch_enable(&have_neon); 47 } 48