text: /*
   * Glue Code for assembler optimized version of Blowfish
   *
   * Copyright © 2011-2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
   *
   * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
   *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
   * CTR part based on code (crypto/ctr.c) by:
   *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
   *
   * 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 <asm/processor.h>
  #include <crypto/blowfish.h>
  #include <linux/crypto.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <crypto/algapi.h>
  #include <asm/crypto/blowfish.h>
  
  /* regular block cipher functions */
  asmlinkage void __blowfish_enc_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src,
  				   bool xor);
  EXPORT_SYMBOL_GPL(__blowfish_enc_blk);
  
  asmlinkage void blowfish_dec_blk(struct bf_ctx *ctx, u8 *dst, const u8 *src);
  EXPORT_SYMBOL_GPL(blowfish_dec_blk);
  
  /* 4-way parallel cipher functions */
  asmlinkage void __blowfish_enc_blk_4way(struct bf_ctx *ctx, u8 *dst,
  					const u8 *src, bool xor);
  EXPORT_SYMBOL_GPL(__blowfish_enc_blk_4way);
  
  asmlinkage void blowfish_dec_blk_4way(struct bf_ctx *ctx, u8 *dst,
  				      const u8 *src);
  EXPORT_SYMBOL_GPL(blowfish_dec_blk_4way);
  
  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 ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
  		     void (*fn)(struct bf_ctx *, u8 *, const u8 *),
  		     void (*fn_4way)(struct bf_ctx *, u8 *, const u8 *))
  {
  	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
  	unsigned int bsize = BF_BLOCK_SIZE;
  	unsigned int nbytes;
  	int err;
  
  	err = blkcipher_walk_virt(desc, walk);
  
  	while ((nbytes = walk->nbytes)) {
  		u8 *wsrc = walk->src.virt.addr;
  		u8 *wdst = walk->dst.virt.addr;
  
  		/* Process four block batch */
  		if (nbytes >= bsize * 4) {
  			do {
  				fn_4way(ctx, wdst, wsrc);
  
  				wsrc += bsize * 4;
  				wdst += bsize * 4;
  				nbytes -= bsize * 4;
  			} while (nbytes >= bsize * 4);
  
  			if (nbytes < bsize)
  				goto done;
  		}
  
  		/* Handle leftovers */
  		do {
  			fn(ctx, wdst, wsrc);
  
  			wsrc += bsize;
  			wdst += bsize;
  			nbytes -= bsize;
  		} while (nbytes >= bsize);
  
  done:
  		err = blkcipher_walk_done(desc, walk, nbytes);
  	}
  
  	return err;
  }
  
  static int ecb_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  		       struct scatterlist *src, unsigned int nbytes)
  {
  	struct blkcipher_walk walk;
  
  	blkcipher_walk_init(&walk, dst, src, nbytes);
  	return ecb_crypt(desc, &walk, blowfish_enc_blk, blowfish_enc_blk_4way);
  }
  
  static int ecb_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  		       struct scatterlist *src, unsigned int nbytes)
  {
  	struct blkcipher_walk walk;
  
  	blkcipher_walk_init(&walk, dst, src, nbytes);
  	return ecb_crypt(desc, &walk, blowfish_dec_blk, blowfish_dec_blk_4way);
  }
  
  static unsigned int __cbc_encrypt(struct blkcipher_desc *desc,
  				  struct blkcipher_walk *walk)
  {
  	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
  	unsigned int bsize = BF_BLOCK_SIZE;
  	unsigned int nbytes = walk->nbytes;
  	u64 *src = (u64 *)walk->src.virt.addr;
  	u64 *dst = (u64 *)walk->dst.virt.addr;
  	u64 *iv = (u64 *)walk->iv;
  
  	do {
  		*dst = *src ^ *iv;
  		blowfish_enc_blk(ctx, (u8 *)dst, (u8 *)dst);
  		iv = dst;
  
  		src += 1;
  		dst += 1;
  		nbytes -= bsize;
  	} while (nbytes >= bsize);
  
  	*(u64 *)walk->iv = *iv;
  	return nbytes;
  }
  
  static int cbc_encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  		       struct scatterlist *src, unsigned int nbytes)
  {
  	struct blkcipher_walk walk;
  	int err;
  
  	blkcipher_walk_init(&walk, dst, src, nbytes);
  	err = blkcipher_walk_virt(desc, &walk);
  
  	while ((nbytes = walk.nbytes)) {
  		nbytes = __cbc_encrypt(desc, &walk);
  		err = blkcipher_walk_done(desc, &walk, nbytes);
  	}
  
  	return err;
  }
  
  static unsigned int __cbc_decrypt(struct blkcipher_desc *desc,
  				  struct blkcipher_walk *walk)
  {
  	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
  	unsigned int bsize = BF_BLOCK_SIZE;
  	unsigned int nbytes = walk->nbytes;
  	u64 *src = (u64 *)walk->src.virt.addr;
  	u64 *dst = (u64 *)walk->dst.virt.addr;
  	u64 ivs[4 - 1];
  	u64 last_iv;
  
  	/* Start of the last block. */
  	src += nbytes / bsize - 1;
  	dst += nbytes / bsize - 1;
  
  	last_iv = *src;
  
  	/* Process four block batch */
  	if (nbytes >= bsize * 4) {
  		do {
  			nbytes -= bsize * 4 - bsize;
  			src -= 4 - 1;
  			dst -= 4 - 1;
  
  			ivs[0] = src[0];
  			ivs[1] = src[1];
  			ivs[2] = src[2];
  
  			blowfish_dec_blk_4way(ctx, (u8 *)dst, (u8 *)src);
  
  			dst[1] ^= ivs[0];
  			dst[2] ^= ivs[1];
  			dst[3] ^= ivs[2];
  
  			nbytes -= bsize;
  			if (nbytes < bsize)
  				goto done;
  
  			*dst ^= *(src - 1);
  			src -= 1;
  			dst -= 1;
  		} while (nbytes >= bsize * 4);
  
  		if (nbytes < bsize)
  			goto done;
  	}
  
  	/* Handle leftovers */
  	for (;;) {
  		blowfish_dec_blk(ctx, (u8 *)dst, (u8 *)src);
  
  		nbytes -= bsize;
  		if (nbytes < bsize)
  			break;
  
  		*dst ^= *(src - 1);
  		src -= 1;
  		dst -= 1;
  	}
  
  done:
  	*dst ^= *(u64 *)walk->iv;
  	*(u64 *)walk->iv = last_iv;
  
  	return nbytes;
  }
  
  static int cbc_decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  		       struct scatterlist *src, unsigned int nbytes)
  {
  	struct blkcipher_walk walk;
  	int err;
  
  	blkcipher_walk_init(&walk, dst, src, nbytes);
  	err = blkcipher_walk_virt(desc, &walk);
  
  	while ((nbytes = walk.nbytes)) {
  		nbytes = __cbc_decrypt(desc, &walk);
  		err = blkcipher_walk_done(desc, &walk, nbytes);
  	}
  
  	return err;
  }
  
  static void ctr_crypt_final(struct bf_ctx *ctx, struct blkcipher_walk *walk)
  {
  	u8 *ctrblk = walk->iv;
  	u8 keystream[BF_BLOCK_SIZE];
  	u8 *src = walk->src.virt.addr;
  	u8 *dst = walk->dst.virt.addr;
  	unsigned int nbytes = walk->nbytes;
  
  	blowfish_enc_blk(ctx, keystream, ctrblk);
  	crypto_xor(keystream, src, nbytes);
  	memcpy(dst, keystream, nbytes);
  
  	crypto_inc(ctrblk, BF_BLOCK_SIZE);
  }
  
  static unsigned int __ctr_crypt(struct blkcipher_desc *desc,
  				struct blkcipher_walk *walk)
  {
  	struct bf_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
  	unsigned int bsize = BF_BLOCK_SIZE;
  	unsigned int nbytes = walk->nbytes;
  	u64 *src = (u64 *)walk->src.virt.addr;
  	u64 *dst = (u64 *)walk->dst.virt.addr;
  	u64 ctrblk = be64_to_cpu(*(__be64 *)walk->iv);
  	__be64 ctrblocks[4];
  
  	/* Process four block batch */
  	if (nbytes >= bsize * 4) {
  		do {
  			if (dst != src) {
  				dst[0] = src[0];
  				dst[1] = src[1];
  				dst[2] = src[2];
  				dst[3] = src[3];
  			}
  
  			/* create ctrblks for parallel encrypt */
  			ctrblocks[0] = cpu_to_be64(ctrblk++);
  			ctrblocks[1] = cpu_to_be64(ctrblk++);
  			ctrblocks[2] = cpu_to_be64(ctrblk++);
  			ctrblocks[3] = cpu_to_be64(ctrblk++);
  
  			blowfish_enc_blk_xor_4way(ctx, (u8 *)dst,
  						  (u8 *)ctrblocks);
  
  			src += 4;
  			dst += 4;
  		} while ((nbytes -= bsize * 4) >= bsize * 4);
  
  		if (nbytes < bsize)
  			goto done;
  	}
  
  	/* Handle leftovers */
  	do {
  		if (dst != src)
  			*dst = *src;
  
  		ctrblocks[0] = cpu_to_be64(ctrblk++);
  
  		blowfish_enc_blk_xor(ctx, (u8 *)dst, (u8 *)ctrblocks);
  
  		src += 1;
  		dst += 1;
  	} while ((nbytes -= bsize) >= bsize);
  
  done:
  	*(__be64 *)walk->iv = cpu_to_be64(ctrblk);
  	return nbytes;
  }
  
  static int ctr_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
  		     struct scatterlist *src, unsigned int nbytes)
  {
  	struct blkcipher_walk walk;
  	int err;
  
  	blkcipher_walk_init(&walk, dst, src, nbytes);
  	err = blkcipher_walk_virt_block(desc, &walk, BF_BLOCK_SIZE);
  
  	while ((nbytes = walk.nbytes) >= BF_BLOCK_SIZE) {
  		nbytes = __ctr_crypt(desc, &walk);
  		err = blkcipher_walk_done(desc, &walk, nbytes);
  	}
  
  	if (walk.nbytes) {
  		ctr_crypt_final(crypto_blkcipher_ctx(desc->tfm), &walk);
  		err = blkcipher_walk_done(desc, &walk, 0);
  	}
  
  	return err;
  }
  
  static struct crypto_alg bf_algs[4] = { {
  	.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_alignmask		= 0,
  	.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,
  		}
  	}
  }, {
  	.cra_name		= "ecb(blowfish)",
  	.cra_driver_name	= "ecb-blowfish-asm",
  	.cra_priority		= 300,
  	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
  	.cra_blocksize		= BF_BLOCK_SIZE,
  	.cra_ctxsize		= sizeof(struct bf_ctx),
  	.cra_alignmask		= 0,
  	.cra_type		= &crypto_blkcipher_type,
  	.cra_module		= THIS_MODULE,
  	.cra_u = {
  		.blkcipher = {
  			.min_keysize	= BF_MIN_KEY_SIZE,
  			.max_keysize	= BF_MAX_KEY_SIZE,
  			.setkey		= blowfish_setkey,
  			.encrypt	= ecb_encrypt,
  			.decrypt	= ecb_decrypt,
  		},
  	},
  }, {
  	.cra_name		= "cbc(blowfish)",
  	.cra_driver_name	= "cbc-blowfish-asm",
  	.cra_priority		= 300,
  	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
  	.cra_blocksize		= BF_BLOCK_SIZE,
  	.cra_ctxsize		= sizeof(struct bf_ctx),
  	.cra_alignmask		= 0,
  	.cra_type		= &crypto_blkcipher_type,
  	.cra_module		= THIS_MODULE,
  	.cra_u = {
  		.blkcipher = {
  			.min_keysize	= BF_MIN_KEY_SIZE,
  			.max_keysize	= BF_MAX_KEY_SIZE,
  			.ivsize		= BF_BLOCK_SIZE,
  			.setkey		= blowfish_setkey,
  			.encrypt	= cbc_encrypt,
  			.decrypt	= cbc_decrypt,
  		},
  	},
  }, {
  	.cra_name		= "ctr(blowfish)",
  	.cra_driver_name	= "ctr-blowfish-asm",
  	.cra_priority		= 300,
  	.cra_flags		= CRYPTO_ALG_TYPE_BLKCIPHER,
  	.cra_blocksize		= 1,
  	.cra_ctxsize		= sizeof(struct bf_ctx),
  	.cra_alignmask		= 0,
  	.cra_type		= &crypto_blkcipher_type,
  	.cra_module		= THIS_MODULE,
  	.cra_u = {
  		.blkcipher = {
  			.min_keysize	= BF_MIN_KEY_SIZE,
  			.max_keysize	= BF_MAX_KEY_SIZE,
  			.ivsize		= BF_BLOCK_SIZE,
  			.setkey		= blowfish_setkey,
  			.encrypt	= ctr_crypt,
  			.decrypt	= ctr_crypt,
  		},
  	},
  } };
  
  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 init(void)
  {
  	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;
  	}
  
  	return crypto_register_algs(bf_algs, ARRAY_SIZE(bf_algs));
  }
  
  static void __exit fini(void)
  {
  	crypto_unregister_algs(bf_algs, ARRAY_SIZE(bf_algs));
  }
  
  module_init(init);
  module_exit(fini);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Blowfish Cipher Algorithm, asm optimized");
  MODULE_ALIAS("blowfish");
  MODULE_ALIAS("blowfish-asm");
  