// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Glue Code for assembler optimized version of Blowfish
 *
 * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
 *
 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/algapi.h>
#include <crypto/blowfish.h>
#include <crypto/internal/skcipher.h>
#include <linux/crypto.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>

#include "ecb_cbc_helpers.h"

/* regular block cipher functions */
asmlinkage void blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);

/* 4-way parallel cipher functions */
asmlinkage void blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
                                      const u8 *src);
asmlinkage void __blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
                                        const u8 *src, bool cbc);

static inline void blowfish_dec_ecb_4way(struct bf_ctx *ctx, u8 *dst,
                                             const u8 *src)
{
        return __blowfish_dec_blk_4way(ctx, dst, src, false);
}

static inline void blowfish_dec_cbc_4way(struct bf_ctx *ctx, u8 *dst,
                                             const u8 *src)
{
        return __blowfish_dec_blk_4way(ctx, dst, src, true);
}

static void blowfish_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
        blowfish_enc_blk(crypto_tfm_ctx(tfm), dst, src);
}

static void blowfish_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
        blowfish_dec_blk(crypto_tfm_ctx(tfm), dst, src);
}

static int blowfish_setkey_skcipher(struct crypto_skcipher *tfm,
                                    const u8 *key, unsigned int keylen)
{
        return blowfish_setkey(&tfm->base, key, keylen);
}

static int ecb_encrypt(struct skcipher_request *req)
{
        ECB_WALK_START(req, BF_BLOCK_SIZE, -1);
        ECB_BLOCK(4, blowfish_enc_blk_4way);
        ECB_BLOCK(1, blowfish_enc_blk);
        ECB_WALK_END();
}

static int ecb_decrypt(struct skcipher_request *req)
{
        ECB_WALK_START(req, BF_BLOCK_SIZE, -1);
        ECB_BLOCK(4, blowfish_dec_ecb_4way);
        ECB_BLOCK(1, blowfish_dec_blk);
        ECB_WALK_END();
}

static int cbc_encrypt(struct skcipher_request *req)
{
        CBC_WALK_START(req, BF_BLOCK_SIZE, -1);
        CBC_ENC_BLOCK(blowfish_enc_blk);
        CBC_WALK_END();
}

static int cbc_decrypt(struct skcipher_request *req)
{
        CBC_WALK_START(req, BF_BLOCK_SIZE, -1);
        CBC_DEC_BLOCK(4, blowfish_dec_cbc_4way);
        CBC_DEC_BLOCK(1, blowfish_dec_blk);
        CBC_WALK_END();
}

static struct crypto_alg bf_cipher_alg = {
        .cra_name               = "blowfish",
        .cra_driver_name        = "blowfish-asm",
        .cra_priority           = 200,
        .cra_flags              = CRYPTO_ALG_TYPE_CIPHER,
        .cra_blocksize          = BF_BLOCK_SIZE,
        .cra_ctxsize            = sizeof(struct bf_ctx),
        .cra_module             = THIS_MODULE,
        .cra_u = {
                .cipher = {
                        .cia_min_keysize        = BF_MIN_KEY_SIZE,
                        .cia_max_keysize        = BF_MAX_KEY_SIZE,
                        .cia_setkey             = blowfish_setkey,
                        .cia_encrypt            = blowfish_encrypt,
                        .cia_decrypt            = blowfish_decrypt,
                }
        }
};

static struct skcipher_alg bf_skcipher_algs[] = {
        {
                .base.cra_name          = "ecb(blowfish)",
                .base.cra_driver_name   = "ecb-blowfish-asm",
                .base.cra_priority      = 300,
                .base.cra_blocksize     = BF_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct bf_ctx),
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = BF_MIN_KEY_SIZE,
                .max_keysize            = BF_MAX_KEY_SIZE,
                .setkey                 = blowfish_setkey_skcipher,
                .encrypt                = ecb_encrypt,
                .decrypt                = ecb_decrypt,
        }, {
                .base.cra_name          = "cbc(blowfish)",
                .base.cra_driver_name   = "cbc-blowfish-asm",
                .base.cra_priority      = 300,
                .base.cra_blocksize     = BF_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct bf_ctx),
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = BF_MIN_KEY_SIZE,
                .max_keysize            = BF_MAX_KEY_SIZE,
                .ivsize                 = BF_BLOCK_SIZE,
                .setkey                 = blowfish_setkey_skcipher,
                .encrypt                = cbc_encrypt,
                .decrypt                = cbc_decrypt,
        },
};

static bool is_blacklisted_cpu(void)
{
        if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
                return false;

        if (boot_cpu_data.x86 == 0x0f) {
                /*
                 * On Pentium 4, blowfish-x86_64 is slower than generic C
                 * implementation because use of 64bit rotates (which are really
                 * slow on P4). Therefore blacklist P4s.
                 */
                return true;
        }

        return false;
}

static int force;
module_param(force, int, 0);
MODULE_PARM_DESC(force, "Force module load, ignore CPU blacklist");

static int __init blowfish_init(void)
{
        int err;

        if (!force && is_blacklisted_cpu()) {
                printk(KERN_INFO
                        "blowfish-x86_64: performance on this CPU "
                        "would be suboptimal: disabling "
                        "blowfish-x86_64.\n");
                return -ENODEV;
        }

        err = crypto_register_alg(&bf_cipher_alg);
        if (err)
                return err;

        err = crypto_register_skciphers(bf_skcipher_algs,
                                        ARRAY_SIZE(bf_skcipher_algs));
        if (err)
                crypto_unregister_alg(&bf_cipher_alg);

        return err;
}

static void __exit blowfish_fini(void)
{
        crypto_unregister_alg(&bf_cipher_alg);
        crypto_unregister_skciphers(bf_skcipher_algs,
                                    ARRAY_SIZE(bf_skcipher_algs));
}

module_init(blowfish_init);
module_exit(blowfish_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Blowfish Cipher Algorithm, asm optimized");
MODULE_ALIAS_CRYPTO("blowfish");
MODULE_ALIAS_CRYPTO("blowfish-asm");