// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API.
 *
 * SHA-512 and SHA-384 Secure Hash Algorithm.
 *
 * Adapted for OCTEON by Aaro Koskinen <aaro.koskinen@iki.fi>.
 *
 * Based on crypto/sha512_generic.c, which is:
 *
 * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) 2003 Kyle McMartin <kyle@debian.org>
 */

#include <linux/mm.h>
#include <crypto/sha.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/module.h>
#include <asm/byteorder.h>
#include <asm/octeon/octeon.h>
#include <crypto/internal/hash.h>

#include "octeon-crypto.h"

/*
 * We pass everything as 64-bit. OCTEON can handle misaligned data.
 */

static void octeon_sha512_store_hash(struct sha512_state *sctx)
{
        write_octeon_64bit_hash_sha512(sctx->state[0], 0);
        write_octeon_64bit_hash_sha512(sctx->state[1], 1);
        write_octeon_64bit_hash_sha512(sctx->state[2], 2);
        write_octeon_64bit_hash_sha512(sctx->state[3], 3);
        write_octeon_64bit_hash_sha512(sctx->state[4], 4);
        write_octeon_64bit_hash_sha512(sctx->state[5], 5);
        write_octeon_64bit_hash_sha512(sctx->state[6], 6);
        write_octeon_64bit_hash_sha512(sctx->state[7], 7);
}

static void octeon_sha512_read_hash(struct sha512_state *sctx)
{
        sctx->state[0] = read_octeon_64bit_hash_sha512(0);
        sctx->state[1] = read_octeon_64bit_hash_sha512(1);
        sctx->state[2] = read_octeon_64bit_hash_sha512(2);
        sctx->state[3] = read_octeon_64bit_hash_sha512(3);
        sctx->state[4] = read_octeon_64bit_hash_sha512(4);
        sctx->state[5] = read_octeon_64bit_hash_sha512(5);
        sctx->state[6] = read_octeon_64bit_hash_sha512(6);
        sctx->state[7] = read_octeon_64bit_hash_sha512(7);
}

static void octeon_sha512_transform(const void *_block)
{
        const u64 *block = _block;

        write_octeon_64bit_block_sha512(block[0], 0);
        write_octeon_64bit_block_sha512(block[1], 1);
        write_octeon_64bit_block_sha512(block[2], 2);
        write_octeon_64bit_block_sha512(block[3], 3);
        write_octeon_64bit_block_sha512(block[4], 4);
        write_octeon_64bit_block_sha512(block[5], 5);
        write_octeon_64bit_block_sha512(block[6], 6);
        write_octeon_64bit_block_sha512(block[7], 7);
        write_octeon_64bit_block_sha512(block[8], 8);
        write_octeon_64bit_block_sha512(block[9], 9);
        write_octeon_64bit_block_sha512(block[10], 10);
        write_octeon_64bit_block_sha512(block[11], 11);
        write_octeon_64bit_block_sha512(block[12], 12);
        write_octeon_64bit_block_sha512(block[13], 13);
        write_octeon_64bit_block_sha512(block[14], 14);
        octeon_sha512_start(block[15]);
}

static int octeon_sha512_init(struct shash_desc *desc)
{
        struct sha512_state *sctx = shash_desc_ctx(desc);

        sctx->state[0] = SHA512_H0;
        sctx->state[1] = SHA512_H1;
        sctx->state[2] = SHA512_H2;
        sctx->state[3] = SHA512_H3;
        sctx->state[4] = SHA512_H4;
        sctx->state[5] = SHA512_H5;
        sctx->state[6] = SHA512_H6;
        sctx->state[7] = SHA512_H7;
        sctx->count[0] = sctx->count[1] = 0;

        return 0;
}

static int octeon_sha384_init(struct shash_desc *desc)
{
        struct sha512_state *sctx = shash_desc_ctx(desc);

        sctx->state[0] = SHA384_H0;
        sctx->state[1] = SHA384_H1;
        sctx->state[2] = SHA384_H2;
        sctx->state[3] = SHA384_H3;
        sctx->state[4] = SHA384_H4;
        sctx->state[5] = SHA384_H5;
        sctx->state[6] = SHA384_H6;
        sctx->state[7] = SHA384_H7;
        sctx->count[0] = sctx->count[1] = 0;

        return 0;
}

static void __octeon_sha512_update(struct sha512_state *sctx, const u8 *data,
                                   unsigned int len)
{
        unsigned int part_len;
        unsigned int index;
        unsigned int i;

        /* Compute number of bytes mod 128. */
        index = sctx->count[0] % SHA512_BLOCK_SIZE;

        /* Update number of bytes. */
        if ((sctx->count[0] += len) < len)
                sctx->count[1]++;

        part_len = SHA512_BLOCK_SIZE - index;

        /* Transform as many times as possible. */
        if (len >= part_len) {
                memcpy(&sctx->buf[index], data, part_len);
                octeon_sha512_transform(sctx->buf);

                for (i = part_len; i + SHA512_BLOCK_SIZE <= len;
                        i += SHA512_BLOCK_SIZE)
                        octeon_sha512_transform(&data[i]);

                index = 0;
        } else {
                i = 0;
        }

        /* Buffer remaining input. */
        memcpy(&sctx->buf[index], &data[i], len - i);
}

static int octeon_sha512_update(struct shash_desc *desc, const u8 *data,
                                unsigned int len)
{
        struct sha512_state *sctx = shash_desc_ctx(desc);
        struct octeon_cop2_state state;
        unsigned long flags;

        /*
         * Small updates never reach the crypto engine, so the generic sha512 is
         * faster because of the heavyweight octeon_crypto_enable() /
         * octeon_crypto_disable().
         */
        if ((sctx->count[0] % SHA512_BLOCK_SIZE) + len < SHA512_BLOCK_SIZE)
                return crypto_sha512_update(desc, data, len);

        flags = octeon_crypto_enable(&state);
        octeon_sha512_store_hash(sctx);

        __octeon_sha512_update(sctx, data, len);

        octeon_sha512_read_hash(sctx);
        octeon_crypto_disable(&state, flags);

        return 0;
}

static int octeon_sha512_final(struct shash_desc *desc, u8 *hash)
{
        struct sha512_state *sctx = shash_desc_ctx(desc);
        static u8 padding[128] = { 0x80, };
        struct octeon_cop2_state state;
        __be64 *dst = (__be64 *)hash;
        unsigned int pad_len;
        unsigned long flags;
        unsigned int index;
        __be64 bits[2];
        int i;

        /* Save number of bits. */
        bits[1] = cpu_to_be64(sctx->count[0] << 3);
        bits[0] = cpu_to_be64(sctx->count[1] << 3 | sctx->count[0] >> 61);

        /* Pad out to 112 mod 128. */
        index = sctx->count[0] & 0x7f;
        pad_len = (index < 112) ? (112 - index) : ((128+112) - index);

        flags = octeon_crypto_enable(&state);
        octeon_sha512_store_hash(sctx);

        __octeon_sha512_update(sctx, padding, pad_len);

        /* Append length (before padding). */
        __octeon_sha512_update(sctx, (const u8 *)bits, sizeof(bits));

        octeon_sha512_read_hash(sctx);
        octeon_crypto_disable(&state, flags);

        /* Store state in digest. */
        for (i = 0; i < 8; i++)
                dst[i] = cpu_to_be64(sctx->state[i]);

        /* Zeroize sensitive information. */
        memset(sctx, 0, sizeof(struct sha512_state));

        return 0;
}

static int octeon_sha384_final(struct shash_desc *desc, u8 *hash)
{
        u8 D[64];

        octeon_sha512_final(desc, D);

        memcpy(hash, D, 48);
        memzero_explicit(D, 64);

        return 0;
}

static struct shash_alg octeon_sha512_algs[2] = { {
        .digestsize     =       SHA512_DIGEST_SIZE,
        .init           =       octeon_sha512_init,
        .update         =       octeon_sha512_update,
        .final          =       octeon_sha512_final,
        .descsize       =       sizeof(struct sha512_state),
        .base           =       {
                .cra_name       =       "sha512",
                .cra_driver_name=       "octeon-sha512",
                .cra_priority   =       OCTEON_CR_OPCODE_PRIORITY,
                .cra_blocksize  =       SHA512_BLOCK_SIZE,
                .cra_module     =       THIS_MODULE,
        }
}, {
        .digestsize     =       SHA384_DIGEST_SIZE,
        .init           =       octeon_sha384_init,
        .update         =       octeon_sha512_update,
        .final          =       octeon_sha384_final,
        .descsize       =       sizeof(struct sha512_state),
        .base           =       {
                .cra_name       =       "sha384",
                .cra_driver_name=       "octeon-sha384",
                .cra_priority   =       OCTEON_CR_OPCODE_PRIORITY,
                .cra_blocksize  =       SHA384_BLOCK_SIZE,
                .cra_module     =       THIS_MODULE,
        }
} };

static int __init octeon_sha512_mod_init(void)
{
        if (!octeon_has_crypto())
                return -ENOTSUPP;
        return crypto_register_shashes(octeon_sha512_algs,
                                       ARRAY_SIZE(octeon_sha512_algs));
}

static void __exit octeon_sha512_mod_fini(void)
{
        crypto_unregister_shashes(octeon_sha512_algs,
                                  ARRAY_SIZE(octeon_sha512_algs));
}

module_init(octeon_sha512_mod_init);
module_exit(octeon_sha512_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-512 and SHA-384 Secure Hash Algorithms (OCTEON)");
MODULE_AUTHOR("Aaro Koskinen <aaro.koskinen@iki.fi>");