curve25519.h

 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
17asmlinkage void curve25519_neon(u8 mypublic[CURVE25519_KEY_SIZE],
18				const u8 secret[CURVE25519_KEY_SIZE],
19				const u8 basepoint[CURVE25519_KEY_SIZE]);
20
21static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);
22
23static 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		scoped_ksimd()
29			curve25519_neon(out, scalar, point);
30	} else {
31		curve25519_generic(out, scalar, point);
32	}
33}
34
35static void curve25519_base_arch(u8 pub[CURVE25519_KEY_SIZE],
36				 const u8 secret[CURVE25519_KEY_SIZE])
37{
38	curve25519_arch(pub, secret, curve25519_base_point);
39}
40
41#define curve25519_mod_init_arch curve25519_mod_init_arch
42static void curve25519_mod_init_arch(void)
43{
44	if (elf_hwcap & HWCAP_NEON)
45		static_branch_enable(&have_neon);
46}