// SPDX-License-Identifier: GPL-2.0-only
/* Glue code for AES encryption optimized for sparc64 crypto opcodes.
 *
 * This is based largely upon arch/x86/crypto/aesni-intel_glue.c
 *
 * Copyright (C) 2008, Intel Corp.
 *    Author: Huang Ying <ying.huang@intel.com>
 *
 * Added RFC4106 AES-GCM support for 128-bit keys under the AEAD
 * interface for 64-bit kernels.
 *    Authors: Adrian Hoban <adrian.hoban@intel.com>
 *             Gabriele Paoloni <gabriele.paoloni@intel.com>
 *             Tadeusz Struk (tadeusz.struk@intel.com)
 *             Aidan O'Mahony (aidan.o.mahony@intel.com)
 *    Copyright (c) 2010, Intel Corporation.
 */

#define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt

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

#include <asm/fpumacro.h>
#include <asm/opcodes.h>
#include <asm/pstate.h>
#include <asm/elf.h>

struct aes_ops {
        void (*load_encrypt_keys)(const u64 *key);
        void (*load_decrypt_keys)(const u64 *key);
        void (*ecb_encrypt)(const u64 *key, const u64 *input, u64 *output,
                            unsigned int len);
        void (*ecb_decrypt)(const u64 *key, const u64 *input, u64 *output,
                            unsigned int len);
        void (*cbc_encrypt)(const u64 *key, const u64 *input, u64 *output,
                            unsigned int len, u64 *iv);
        void (*cbc_decrypt)(const u64 *key, const u64 *input, u64 *output,
                            unsigned int len, u64 *iv);
        void (*ctr_crypt)(const u64 *key, const u64 *input, u64 *output,
                          unsigned int len, u64 *iv);
};

struct crypto_sparc64_aes_ctx {
        struct aes_ops *ops;
        u64 key[AES_MAX_KEYLENGTH / sizeof(u64)];
        u32 key_length;
        u32 expanded_key_length;
};

static struct aes_ops aes128_ops = {
        .load_encrypt_keys      = aes_sparc64_load_encrypt_keys_128,
        .load_decrypt_keys      = aes_sparc64_load_decrypt_keys_128,
        .ecb_encrypt            = aes_sparc64_ecb_encrypt_128,
        .ecb_decrypt            = aes_sparc64_ecb_decrypt_128,
        .cbc_encrypt            = aes_sparc64_cbc_encrypt_128,
        .cbc_decrypt            = aes_sparc64_cbc_decrypt_128,
        .ctr_crypt              = aes_sparc64_ctr_crypt_128,
};

static struct aes_ops aes192_ops = {
        .load_encrypt_keys      = aes_sparc64_load_encrypt_keys_192,
        .load_decrypt_keys      = aes_sparc64_load_decrypt_keys_192,
        .ecb_encrypt            = aes_sparc64_ecb_encrypt_192,
        .ecb_decrypt            = aes_sparc64_ecb_decrypt_192,
        .cbc_encrypt            = aes_sparc64_cbc_encrypt_192,
        .cbc_decrypt            = aes_sparc64_cbc_decrypt_192,
        .ctr_crypt              = aes_sparc64_ctr_crypt_192,
};

static struct aes_ops aes256_ops = {
        .load_encrypt_keys      = aes_sparc64_load_encrypt_keys_256,
        .load_decrypt_keys      = aes_sparc64_load_decrypt_keys_256,
        .ecb_encrypt            = aes_sparc64_ecb_encrypt_256,
        .ecb_decrypt            = aes_sparc64_ecb_decrypt_256,
        .cbc_encrypt            = aes_sparc64_cbc_encrypt_256,
        .cbc_decrypt            = aes_sparc64_cbc_decrypt_256,
        .ctr_crypt              = aes_sparc64_ctr_crypt_256,
};

static int aes_set_key_skcipher(struct crypto_skcipher *tfm, const u8 *in_key,
                                unsigned int key_len)
{
        struct crypto_sparc64_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

        switch (key_len) {
        case AES_KEYSIZE_128:
                ctx->expanded_key_length = 0xb0;
                ctx->ops = &aes128_ops;
                break;

        case AES_KEYSIZE_192:
                ctx->expanded_key_length = 0xd0;
                ctx->ops = &aes192_ops;
                break;

        case AES_KEYSIZE_256:
                ctx->expanded_key_length = 0xf0;
                ctx->ops = &aes256_ops;
                break;

        default:
                return -EINVAL;
        }

        aes_sparc64_key_expand((const u32 *)in_key, &ctx->key[0], key_len);
        ctx->key_length = key_len;

        return 0;
}

static int ecb_encrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        const struct crypto_sparc64_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_walk walk;
        unsigned int nbytes;
        int err;

        err = skcipher_walk_virt(&walk, req, true);
        if (err)
                return err;

        ctx->ops->load_encrypt_keys(&ctx->key[0]);
        while ((nbytes = walk.nbytes) != 0) {
                ctx->ops->ecb_encrypt(&ctx->key[0], walk.src.virt.addr,
                                      walk.dst.virt.addr,
                                      round_down(nbytes, AES_BLOCK_SIZE));
                err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
        }
        fprs_write(0);
        return err;
}

static int ecb_decrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        const struct crypto_sparc64_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
        const u64 *key_end;
        struct skcipher_walk walk;
        unsigned int nbytes;
        int err;

        err = skcipher_walk_virt(&walk, req, true);
        if (err)
                return err;

        ctx->ops->load_decrypt_keys(&ctx->key[0]);
        key_end = &ctx->key[ctx->expanded_key_length / sizeof(u64)];
        while ((nbytes = walk.nbytes) != 0) {
                ctx->ops->ecb_decrypt(key_end, walk.src.virt.addr,
                                      walk.dst.virt.addr,
                                      round_down(nbytes, AES_BLOCK_SIZE));
                err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
        }
        fprs_write(0);

        return err;
}

static int cbc_encrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        const struct crypto_sparc64_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_walk walk;
        unsigned int nbytes;
        int err;

        err = skcipher_walk_virt(&walk, req, true);
        if (err)
                return err;

        ctx->ops->load_encrypt_keys(&ctx->key[0]);
        while ((nbytes = walk.nbytes) != 0) {
                ctx->ops->cbc_encrypt(&ctx->key[0], walk.src.virt.addr,
                                      walk.dst.virt.addr,
                                      round_down(nbytes, AES_BLOCK_SIZE),
                                      walk.iv);
                err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
        }
        fprs_write(0);
        return err;
}

static int cbc_decrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        const struct crypto_sparc64_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
        const u64 *key_end;
        struct skcipher_walk walk;
        unsigned int nbytes;
        int err;

        err = skcipher_walk_virt(&walk, req, true);
        if (err)
                return err;

        ctx->ops->load_decrypt_keys(&ctx->key[0]);
        key_end = &ctx->key[ctx->expanded_key_length / sizeof(u64)];
        while ((nbytes = walk.nbytes) != 0) {
                ctx->ops->cbc_decrypt(key_end, walk.src.virt.addr,
                                      walk.dst.virt.addr,
                                      round_down(nbytes, AES_BLOCK_SIZE),
                                      walk.iv);
                err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
        }
        fprs_write(0);

        return err;
}

static void ctr_crypt_final(const struct crypto_sparc64_aes_ctx *ctx,
                            struct skcipher_walk *walk)
{
        u8 *ctrblk = walk->iv;
        u64 keystream[AES_BLOCK_SIZE / sizeof(u64)];
        const u8 *src = walk->src.virt.addr;
        u8 *dst = walk->dst.virt.addr;
        unsigned int nbytes = walk->nbytes;

        ctx->ops->ecb_encrypt(&ctx->key[0], (const u64 *)ctrblk,
                              keystream, AES_BLOCK_SIZE);
        crypto_xor_cpy(dst, (u8 *) keystream, src, nbytes);
        crypto_inc(ctrblk, AES_BLOCK_SIZE);
}

static int ctr_crypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        const struct crypto_sparc64_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_walk walk;
        unsigned int nbytes;
        int err;

        err = skcipher_walk_virt(&walk, req, true);
        if (err)
                return err;

        ctx->ops->load_encrypt_keys(&ctx->key[0]);
        while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
                ctx->ops->ctr_crypt(&ctx->key[0], walk.src.virt.addr,
                                    walk.dst.virt.addr,
                                    round_down(nbytes, AES_BLOCK_SIZE),
                                    walk.iv);
                err = skcipher_walk_done(&walk, nbytes % AES_BLOCK_SIZE);
        }
        if (walk.nbytes) {
                ctr_crypt_final(ctx, &walk);
                err = skcipher_walk_done(&walk, 0);
        }
        fprs_write(0);
        return err;
}

static struct skcipher_alg skcipher_algs[] = {
        {
                .base.cra_name          = "ecb(aes)",
                .base.cra_driver_name   = "ecb-aes-sparc64",
                .base.cra_priority      = SPARC_CR_OPCODE_PRIORITY,
                .base.cra_blocksize     = AES_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct crypto_sparc64_aes_ctx),
                .base.cra_alignmask     = 7,
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = AES_MIN_KEY_SIZE,
                .max_keysize            = AES_MAX_KEY_SIZE,
                .setkey                 = aes_set_key_skcipher,
                .encrypt                = ecb_encrypt,
                .decrypt                = ecb_decrypt,
        }, {
                .base.cra_name          = "cbc(aes)",
                .base.cra_driver_name   = "cbc-aes-sparc64",
                .base.cra_priority      = SPARC_CR_OPCODE_PRIORITY,
                .base.cra_blocksize     = AES_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct crypto_sparc64_aes_ctx),
                .base.cra_alignmask     = 7,
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = AES_MIN_KEY_SIZE,
                .max_keysize            = AES_MAX_KEY_SIZE,
                .ivsize                 = AES_BLOCK_SIZE,
                .setkey                 = aes_set_key_skcipher,
                .encrypt                = cbc_encrypt,
                .decrypt                = cbc_decrypt,
        }, {
                .base.cra_name          = "ctr(aes)",
                .base.cra_driver_name   = "ctr-aes-sparc64",
                .base.cra_priority      = SPARC_CR_OPCODE_PRIORITY,
                .base.cra_blocksize     = 1,
                .base.cra_ctxsize       = sizeof(struct crypto_sparc64_aes_ctx),
                .base.cra_alignmask     = 7,
                .base.cra_module        = THIS_MODULE,
                .min_keysize            = AES_MIN_KEY_SIZE,
                .max_keysize            = AES_MAX_KEY_SIZE,
                .ivsize                 = AES_BLOCK_SIZE,
                .setkey                 = aes_set_key_skcipher,
                .encrypt                = ctr_crypt,
                .decrypt                = ctr_crypt,
                .chunksize              = AES_BLOCK_SIZE,
        }
};

static bool __init sparc64_has_aes_opcode(void)
{
        unsigned long cfr;

        if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
                return false;

        __asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
        if (!(cfr & CFR_AES))
                return false;

        return true;
}

static int __init aes_sparc64_mod_init(void)
{
        if (!sparc64_has_aes_opcode()) {
                pr_info("sparc64 aes opcodes not available.\n");
                return -ENODEV;
        }
        pr_info("Using sparc64 aes opcodes optimized AES implementation\n");
        return crypto_register_skciphers(skcipher_algs,
                                         ARRAY_SIZE(skcipher_algs));
}

static void __exit aes_sparc64_mod_fini(void)
{
        crypto_unregister_skciphers(skcipher_algs, ARRAY_SIZE(skcipher_algs));
}

module_init(aes_sparc64_mod_init);
module_exit(aes_sparc64_mod_fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm, sparc64 aes opcode accelerated");

MODULE_ALIAS_CRYPTO("aes");

#include "crop_devid.c"