/* SPDX-License-Identifier: GPL-2.0 */
/*
 * OpenSSL/Cryptogams accelerated Poly1305 transform for ARM
 *
 * Copyright (C) 2019 Linaro Ltd. <ard.biesheuvel@linaro.org>
 */

#include <asm/hwcap.h>
#include <asm/simd.h>
#include <linux/cpufeature.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>

asmlinkage void poly1305_block_init(struct poly1305_block_state *state,
                                    const u8 raw_key[POLY1305_BLOCK_SIZE]);
asmlinkage void poly1305_blocks_arm(struct poly1305_block_state *state,
                                    const u8 *src, u32 len, u32 hibit);
asmlinkage void poly1305_blocks_neon(struct poly1305_block_state *state,
                                     const u8 *src, u32 len, u32 hibit);
asmlinkage void poly1305_emit(const struct poly1305_state *state,
                              u8 digest[POLY1305_DIGEST_SIZE],
                              const u32 nonce[4]);

static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);

static void poly1305_blocks(struct poly1305_block_state *state, const u8 *src,
                            unsigned int len, u32 padbit)
{
        if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) &&
            static_branch_likely(&have_neon) && likely(may_use_simd())) {
                do {
                        unsigned int todo = min_t(unsigned int, len, SZ_4K);

                        scoped_ksimd()
                                poly1305_blocks_neon(state, src, todo, padbit);

                        len -= todo;
                        src += todo;
                } while (len);
        } else
                poly1305_blocks_arm(state, src, len, padbit);
}

#ifdef CONFIG_KERNEL_MODE_NEON
#define poly1305_mod_init_arch poly1305_mod_init_arch
static void poly1305_mod_init_arch(void)
{
        if (elf_hwcap & HWCAP_NEON)
                static_branch_enable(&have_neon);
}
#endif /* CONFIG_KERNEL_MODE_NEON */