/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Glue Code for the AVX2/AES-NI/GFNI assembler implementation of the ARIA Cipher
 *
 * Copyright (c) 2022 Taehee Yoo <ap420073@gmail.com>
 */

#include <crypto/algapi.h>
#include <crypto/aria.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/types.h>

#include "ecb_cbc_helpers.h"
#include "aria-avx.h"

asmlinkage void aria_aesni_avx2_encrypt_32way(const void *ctx, u8 *dst,
                                              const u8 *src);
EXPORT_SYMBOL_GPL(aria_aesni_avx2_encrypt_32way);
asmlinkage void aria_aesni_avx2_decrypt_32way(const void *ctx, u8 *dst,
                                              const u8 *src);
EXPORT_SYMBOL_GPL(aria_aesni_avx2_decrypt_32way);
asmlinkage void aria_aesni_avx2_ctr_crypt_32way(const void *ctx, u8 *dst,
                                                const u8 *src,
                                                u8 *keystream, u8 *iv);
EXPORT_SYMBOL_GPL(aria_aesni_avx2_ctr_crypt_32way);
asmlinkage void aria_aesni_avx2_gfni_encrypt_32way(const void *ctx, u8 *dst,
                                                   const u8 *src);
EXPORT_SYMBOL_GPL(aria_aesni_avx2_gfni_encrypt_32way);
asmlinkage void aria_aesni_avx2_gfni_decrypt_32way(const void *ctx, u8 *dst,
                                                   const u8 *src);
EXPORT_SYMBOL_GPL(aria_aesni_avx2_gfni_decrypt_32way);
asmlinkage void aria_aesni_avx2_gfni_ctr_crypt_32way(const void *ctx, u8 *dst,
                                                     const u8 *src,
                                                     u8 *keystream, u8 *iv);
EXPORT_SYMBOL_GPL(aria_aesni_avx2_gfni_ctr_crypt_32way);

static struct aria_avx_ops aria_ops;

struct aria_avx2_request_ctx {
        u8 keystream[ARIA_AESNI_AVX2_PARALLEL_BLOCK_SIZE];
};

static int ecb_do_encrypt(struct skcipher_request *req, const u32 *rkey)
{
        ECB_WALK_START(req, ARIA_BLOCK_SIZE, ARIA_AESNI_PARALLEL_BLOCKS);
        ECB_BLOCK(ARIA_AESNI_AVX2_PARALLEL_BLOCKS, aria_ops.aria_encrypt_32way);
        ECB_BLOCK(ARIA_AESNI_PARALLEL_BLOCKS, aria_ops.aria_encrypt_16way);
        ECB_BLOCK(1, aria_encrypt);
        ECB_WALK_END();
}

static int ecb_do_decrypt(struct skcipher_request *req, const u32 *rkey)
{
        ECB_WALK_START(req, ARIA_BLOCK_SIZE, ARIA_AESNI_PARALLEL_BLOCKS);
        ECB_BLOCK(ARIA_AESNI_AVX2_PARALLEL_BLOCKS, aria_ops.aria_decrypt_32way);
        ECB_BLOCK(ARIA_AESNI_PARALLEL_BLOCKS, aria_ops.aria_decrypt_16way);
        ECB_BLOCK(1, aria_decrypt);
        ECB_WALK_END();
}

static int aria_avx2_ecb_encrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct aria_ctx *ctx = crypto_skcipher_ctx(tfm);

        return ecb_do_encrypt(req, ctx->enc_key[0]);
}

static int aria_avx2_ecb_decrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct aria_ctx *ctx = crypto_skcipher_ctx(tfm);

        return ecb_do_decrypt(req, ctx->dec_key[0]);
}

static int aria_avx2_set_key(struct crypto_skcipher *tfm, const u8 *key,
                            unsigned int keylen)
{
        return aria_set_key(&tfm->base, key, keylen);
}

static int aria_avx2_ctr_encrypt(struct skcipher_request *req)
{
        struct aria_avx2_request_ctx *req_ctx = skcipher_request_ctx(req);
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct aria_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_walk walk;
        unsigned int nbytes;
        int err;

        err = skcipher_walk_virt(&walk, req, false);

        while ((nbytes = walk.nbytes) > 0) {
                const u8 *src = walk.src.virt.addr;
                u8 *dst = walk.dst.virt.addr;

                while (nbytes >= ARIA_AESNI_AVX2_PARALLEL_BLOCK_SIZE) {
                        kernel_fpu_begin();
                        aria_ops.aria_ctr_crypt_32way(ctx, dst, src,
                                                      &req_ctx->keystream[0],
                                                      walk.iv);
                        kernel_fpu_end();
                        dst += ARIA_AESNI_AVX2_PARALLEL_BLOCK_SIZE;
                        src += ARIA_AESNI_AVX2_PARALLEL_BLOCK_SIZE;
                        nbytes -= ARIA_AESNI_AVX2_PARALLEL_BLOCK_SIZE;
                }

                while (nbytes >= ARIA_AESNI_PARALLEL_BLOCK_SIZE) {
                        kernel_fpu_begin();
                        aria_ops.aria_ctr_crypt_16way(ctx, dst, src,
                                                      &req_ctx->keystream[0],
                                                      walk.iv);
                        kernel_fpu_end();
                        dst += ARIA_AESNI_PARALLEL_BLOCK_SIZE;
                        src += ARIA_AESNI_PARALLEL_BLOCK_SIZE;
                        nbytes -= ARIA_AESNI_PARALLEL_BLOCK_SIZE;
                }

                while (nbytes >= ARIA_BLOCK_SIZE) {
                        memcpy(&req_ctx->keystream[0], walk.iv, ARIA_BLOCK_SIZE);
                        crypto_inc(walk.iv, ARIA_BLOCK_SIZE);

                        aria_encrypt(ctx, &req_ctx->keystream[0],
                                     &req_ctx->keystream[0]);

                        crypto_xor_cpy(dst, src, &req_ctx->keystream[0],
                                       ARIA_BLOCK_SIZE);
                        dst += ARIA_BLOCK_SIZE;
                        src += ARIA_BLOCK_SIZE;
                        nbytes -= ARIA_BLOCK_SIZE;
                }

                if (walk.nbytes == walk.total && nbytes > 0) {
                        memcpy(&req_ctx->keystream[0], walk.iv,
                               ARIA_BLOCK_SIZE);
                        crypto_inc(walk.iv, ARIA_BLOCK_SIZE);

                        aria_encrypt(ctx, &req_ctx->keystream[0],
                                     &req_ctx->keystream[0]);

                        crypto_xor_cpy(dst, src, &req_ctx->keystream[0],
                                       nbytes);
                        dst += nbytes;
                        src += nbytes;
                        nbytes = 0;
                }
                err = skcipher_walk_done(&walk, nbytes);
        }

        return err;
}

static int aria_avx2_init_tfm(struct crypto_skcipher *tfm)
{
        crypto_skcipher_set_reqsize(tfm, sizeof(struct aria_avx2_request_ctx));

        return 0;
}

static struct skcipher_alg aria_algs[] = {
        {
                .base.cra_name          = "ecb(aria)",
                .base.cra_driver_name   = "ecb-aria-avx2",
                .base.cra_priority      = 500,
                .base.cra_blocksize     = ARIA_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct aria_ctx),
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = ARIA_MIN_KEY_SIZE,
                .max_keysize            = ARIA_MAX_KEY_SIZE,
                .setkey                 = aria_avx2_set_key,
                .encrypt                = aria_avx2_ecb_encrypt,
                .decrypt                = aria_avx2_ecb_decrypt,
        }, {
                .base.cra_name          = "ctr(aria)",
                .base.cra_driver_name   = "ctr-aria-avx2",
                .base.cra_priority      = 500,
                .base.cra_flags         = CRYPTO_ALG_SKCIPHER_REQSIZE_LARGE,
                .base.cra_blocksize     = 1,
                .base.cra_ctxsize       = sizeof(struct aria_ctx),
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = ARIA_MIN_KEY_SIZE,
                .max_keysize            = ARIA_MAX_KEY_SIZE,
                .ivsize                 = ARIA_BLOCK_SIZE,
                .chunksize              = ARIA_BLOCK_SIZE,
                .setkey                 = aria_avx2_set_key,
                .encrypt                = aria_avx2_ctr_encrypt,
                .decrypt                = aria_avx2_ctr_encrypt,
                .init                   = aria_avx2_init_tfm,
        }
};

static int __init aria_avx2_init(void)
{
        const char *feature_name;

        if (!boot_cpu_has(X86_FEATURE_AVX) ||
            !boot_cpu_has(X86_FEATURE_AVX2) ||
            !boot_cpu_has(X86_FEATURE_AES) ||
            !boot_cpu_has(X86_FEATURE_OSXSAVE)) {
                pr_info("AVX2 or AES-NI instructions are not detected.\n");
                return -ENODEV;
        }

        if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM,
                                &feature_name)) {
                pr_info("CPU feature '%s' is not supported.\n", feature_name);
                return -ENODEV;
        }

        if (boot_cpu_has(X86_FEATURE_GFNI)) {
                aria_ops.aria_encrypt_16way = aria_aesni_avx_gfni_encrypt_16way;
                aria_ops.aria_decrypt_16way = aria_aesni_avx_gfni_decrypt_16way;
                aria_ops.aria_ctr_crypt_16way = aria_aesni_avx_gfni_ctr_crypt_16way;
                aria_ops.aria_encrypt_32way = aria_aesni_avx2_gfni_encrypt_32way;
                aria_ops.aria_decrypt_32way = aria_aesni_avx2_gfni_decrypt_32way;
                aria_ops.aria_ctr_crypt_32way = aria_aesni_avx2_gfni_ctr_crypt_32way;
        } else {
                aria_ops.aria_encrypt_16way = aria_aesni_avx_encrypt_16way;
                aria_ops.aria_decrypt_16way = aria_aesni_avx_decrypt_16way;
                aria_ops.aria_ctr_crypt_16way = aria_aesni_avx_ctr_crypt_16way;
                aria_ops.aria_encrypt_32way = aria_aesni_avx2_encrypt_32way;
                aria_ops.aria_decrypt_32way = aria_aesni_avx2_decrypt_32way;
                aria_ops.aria_ctr_crypt_32way = aria_aesni_avx2_ctr_crypt_32way;
        }

        return crypto_register_skciphers(aria_algs, ARRAY_SIZE(aria_algs));
}

static void __exit aria_avx2_exit(void)
{
        crypto_unregister_skciphers(aria_algs, ARRAY_SIZE(aria_algs));
}

module_init(aria_avx2_init);
module_exit(aria_avx2_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Taehee Yoo <ap420073@gmail.com>");
MODULE_DESCRIPTION("ARIA Cipher Algorithm, AVX2/AES-NI/GFNI optimized");
MODULE_ALIAS_CRYPTO("aria");
MODULE_ALIAS_CRYPTO("aria-aesni-avx2");