text: /*
   * Glue Code for AVX assembler version of Twofish Cipher
   *
   * Copyright (C) 2012 Johannes Goetzfried
   *     <Johannes.Goetzfried@informatik.stud.uni-erlangen.de>
   *
   * Copyright © 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
   * USA
   *
   */
  
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/crypto.h>
  #include <linux/err.h>
  #include <crypto/algapi.h>
  #include <crypto/internal/simd.h>
  #include <crypto/twofish.h>
  #include <crypto/xts.h>
  #include <asm/crypto/glue_helper.h>
  #include <asm/crypto/twofish.h>
  
  #define TWOFISH_PARALLEL_BLOCKS 8
  
  /* 8-way parallel cipher functions */
  asmlinkage void twofish_ecb_enc_8way(struct twofish_ctx *ctx, u8 *dst,
  				     const u8 *src);
  asmlinkage void twofish_ecb_dec_8way(struct twofish_ctx *ctx, u8 *dst,
  				     const u8 *src);
  
  asmlinkage void twofish_cbc_dec_8way(struct twofish_ctx *ctx, u8 *dst,
  				     const u8 *src);
  asmlinkage void twofish_ctr_8way(struct twofish_ctx *ctx, u8 *dst,
  				 const u8 *src, le128 *iv);
  
  asmlinkage void twofish_xts_enc_8way(struct twofish_ctx *ctx, u8 *dst,
  				     const u8 *src, le128 *iv);
  asmlinkage void twofish_xts_dec_8way(struct twofish_ctx *ctx, u8 *dst,
  				     const u8 *src, le128 *iv);
  
  static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,
  				   const u8 *key, unsigned int keylen)
  {
  	return twofish_setkey(&tfm->base, key, keylen);
  }
  
  static inline void twofish_enc_blk_3way(struct twofish_ctx *ctx, u8 *dst,
  					const u8 *src)
  {
  	__twofish_enc_blk_3way(ctx, dst, src, false);
  }
  
  static void twofish_xts_enc(void *ctx, u128 *dst, const u128 *src, le128 *iv)
  {
  	glue_xts_crypt_128bit_one(ctx, dst, src, iv,
  				  GLUE_FUNC_CAST(twofish_enc_blk));
  }
  
  static void twofish_xts_dec(void *ctx, u128 *dst, const u128 *src, le128 *iv)
  {
  	glue_xts_crypt_128bit_one(ctx, dst, src, iv,
  				  GLUE_FUNC_CAST(twofish_dec_blk));
  }
  
  struct twofish_xts_ctx {
  	struct twofish_ctx tweak_ctx;
  	struct twofish_ctx crypt_ctx;
  };
  
  static int xts_twofish_setkey(struct crypto_skcipher *tfm, const u8 *key,
  			      unsigned int keylen)
  {
  	struct twofish_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
  	u32 *flags = &tfm->base.crt_flags;
  	int err;
  
  	err = xts_verify_key(tfm, key, keylen);
  	if (err)
  		return err;
  
  	/* first half of xts-key is for crypt */
  	err = __twofish_setkey(&ctx->crypt_ctx, key, keylen / 2, flags);
  	if (err)
  		return err;
  
  	/* second half of xts-key is for tweak */
  	return __twofish_setkey(&ctx->tweak_ctx, key + keylen / 2, keylen / 2,
  				flags);
  }
  
  static const struct common_glue_ctx twofish_enc = {
  	.num_funcs = 3,
  	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
  
  	.funcs = { {
  		.num_blocks = TWOFISH_PARALLEL_BLOCKS,
  		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_ecb_enc_8way) }
  	}, {
  		.num_blocks = 3,
  		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_3way) }
  	}, {
  		.num_blocks = 1,
  		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk) }
  	} }
  };
  
  static const struct common_glue_ctx twofish_ctr = {
  	.num_funcs = 3,
  	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
  
  	.funcs = { {
  		.num_blocks = TWOFISH_PARALLEL_BLOCKS,
  		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(twofish_ctr_8way) }
  	}, {
  		.num_blocks = 3,
  		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(twofish_enc_blk_ctr_3way) }
  	}, {
  		.num_blocks = 1,
  		.fn_u = { .ctr = GLUE_CTR_FUNC_CAST(twofish_enc_blk_ctr) }
  	} }
  };
  
  static const struct common_glue_ctx twofish_enc_xts = {
  	.num_funcs = 2,
  	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
  
  	.funcs = { {
  		.num_blocks = TWOFISH_PARALLEL_BLOCKS,
  		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_enc_8way) }
  	}, {
  		.num_blocks = 1,
  		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_enc) }
  	} }
  };
  
  static const struct common_glue_ctx twofish_dec = {
  	.num_funcs = 3,
  	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
  
  	.funcs = { {
  		.num_blocks = TWOFISH_PARALLEL_BLOCKS,
  		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_ecb_dec_8way) }
  	}, {
  		.num_blocks = 3,
  		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk_3way) }
  	}, {
  		.num_blocks = 1,
  		.fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk) }
  	} }
  };
  
  static const struct common_glue_ctx twofish_dec_cbc = {
  	.num_funcs = 3,
  	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
  
  	.funcs = { {
  		.num_blocks = TWOFISH_PARALLEL_BLOCKS,
  		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_cbc_dec_8way) }
  	}, {
  		.num_blocks = 3,
  		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk_cbc_3way) }
  	}, {
  		.num_blocks = 1,
  		.fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk) }
  	} }
  };
  
  static const struct common_glue_ctx twofish_dec_xts = {
  	.num_funcs = 2,
  	.fpu_blocks_limit = TWOFISH_PARALLEL_BLOCKS,
  
  	.funcs = { {
  		.num_blocks = TWOFISH_PARALLEL_BLOCKS,
  		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_dec_8way) }
  	}, {
  		.num_blocks = 1,
  		.fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_dec) }
  	} }
  };
  
  static int ecb_encrypt(struct skcipher_request *req)
  {
  	return glue_ecb_req_128bit(&twofish_enc, req);
  }
  
  static int ecb_decrypt(struct skcipher_request *req)
  {
  	return glue_ecb_req_128bit(&twofish_dec, req);
  }
  
  static int cbc_encrypt(struct skcipher_request *req)
  {
  	return glue_cbc_encrypt_req_128bit(GLUE_FUNC_CAST(twofish_enc_blk),
  					   req);
  }
  
  static int cbc_decrypt(struct skcipher_request *req)
  {
  	return glue_cbc_decrypt_req_128bit(&twofish_dec_cbc, req);
  }
  
  static int ctr_crypt(struct skcipher_request *req)
  {
  	return glue_ctr_req_128bit(&twofish_ctr, req);
  }
  
  static int xts_encrypt(struct skcipher_request *req)
  {
  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  	struct twofish_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
  
  	return glue_xts_req_128bit(&twofish_enc_xts, req,
  				   XTS_TWEAK_CAST(twofish_enc_blk),
  				   &ctx->tweak_ctx, &ctx->crypt_ctx);
  }
  
  static int xts_decrypt(struct skcipher_request *req)
  {
  	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  	struct twofish_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
  
  	return glue_xts_req_128bit(&twofish_dec_xts, req,
  				   XTS_TWEAK_CAST(twofish_enc_blk),
  				   &ctx->tweak_ctx, &ctx->crypt_ctx);
  }
  
  static struct skcipher_alg twofish_algs[] = {
  	{
  		.base.cra_name		= "__ecb(twofish)",
  		.base.cra_driver_name	= "__ecb-twofish-avx",
  		.base.cra_priority	= 400,
  		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
  		.base.cra_blocksize	= TF_BLOCK_SIZE,
  		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
  		.base.cra_module	= THIS_MODULE,
  		.min_keysize		= TF_MIN_KEY_SIZE,
  		.max_keysize		= TF_MAX_KEY_SIZE,
  		.setkey			= twofish_setkey_skcipher,
  		.encrypt		= ecb_encrypt,
  		.decrypt		= ecb_decrypt,
  	}, {
  		.base.cra_name		= "__cbc(twofish)",
  		.base.cra_driver_name	= "__cbc-twofish-avx",
  		.base.cra_priority	= 400,
  		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
  		.base.cra_blocksize	= TF_BLOCK_SIZE,
  		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
  		.base.cra_module	= THIS_MODULE,
  		.min_keysize		= TF_MIN_KEY_SIZE,
  		.max_keysize		= TF_MAX_KEY_SIZE,
  		.ivsize			= TF_BLOCK_SIZE,
  		.setkey			= twofish_setkey_skcipher,
  		.encrypt		= cbc_encrypt,
  		.decrypt		= cbc_decrypt,
  	}, {
  		.base.cra_name		= "__ctr(twofish)",
  		.base.cra_driver_name	= "__ctr-twofish-avx",
  		.base.cra_priority	= 400,
  		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
  		.base.cra_blocksize	= 1,
  		.base.cra_ctxsize	= sizeof(struct twofish_ctx),
  		.base.cra_module	= THIS_MODULE,
  		.min_keysize		= TF_MIN_KEY_SIZE,
  		.max_keysize		= TF_MAX_KEY_SIZE,
  		.ivsize			= TF_BLOCK_SIZE,
  		.chunksize		= TF_BLOCK_SIZE,
  		.setkey			= twofish_setkey_skcipher,
  		.encrypt		= ctr_crypt,
  		.decrypt		= ctr_crypt,
  	}, {
  		.base.cra_name		= "__xts(twofish)",
  		.base.cra_driver_name	= "__xts-twofish-avx",
  		.base.cra_priority	= 400,
  		.base.cra_flags		= CRYPTO_ALG_INTERNAL,
  		.base.cra_blocksize	= TF_BLOCK_SIZE,
  		.base.cra_ctxsize	= sizeof(struct twofish_xts_ctx),
  		.base.cra_module	= THIS_MODULE,
  		.min_keysize		= 2 * TF_MIN_KEY_SIZE,
  		.max_keysize		= 2 * TF_MAX_KEY_SIZE,
  		.ivsize			= TF_BLOCK_SIZE,
  		.setkey			= xts_twofish_setkey,
  		.encrypt		= xts_encrypt,
  		.decrypt		= xts_decrypt,
  	},
  };
  
  static struct simd_skcipher_alg *twofish_simd_algs[ARRAY_SIZE(twofish_algs)];
  
  static int __init twofish_init(void)
  {
  	const char *feature_name;
  
  	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;
  	}
  
  	return simd_register_skciphers_compat(twofish_algs,
  					      ARRAY_SIZE(twofish_algs),
  					      twofish_simd_algs);
  }
  
  static void __exit twofish_exit(void)
  {
  	simd_unregister_skciphers(twofish_algs, ARRAY_SIZE(twofish_algs),
  				  twofish_simd_algs);
  }
  
  module_init(twofish_init);
  module_exit(twofish_exit);
  
  MODULE_DESCRIPTION("Twofish Cipher Algorithm, AVX optimized");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS_CRYPTO("twofish");
  