arch/x86/crypto/glue_helper.c - linux - Git at Google

 /*
  * Shared glue code for 128bit block ciphers
  *
  * Copyright © 2012-2013 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 <linux/module.h>
 #include <crypto/b128ops.h>
 #include <crypto/lrw.h>
 #include <crypto/xts.h>
 #include <asm/crypto/glue_helper.h>
 #include <crypto/scatterwalk.h>

 static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
 				   struct blkcipher_desc *desc,
 				   struct blkcipher_walk *walk)
 {
 	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 	const unsigned int bsize = 128 / 8;
 	unsigned int nbytes, i, func_bytes;
 	bool fpu_enabled = false;
 	int err;

 	err = blkcipher_walk_virt(desc, walk);

 	while ((nbytes = walk->nbytes)) {
 		u8 *wsrc = walk->src.virt.addr;
 		u8 *wdst = walk->dst.virt.addr;

 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
 					     desc, fpu_enabled, nbytes);

 		for (i = 0; i < gctx->num_funcs; i++) {
 			func_bytes = bsize * gctx->funcs[i].num_blocks;

 			/* Process multi-block batch */
 			if (nbytes >= func_bytes) {
 				do {
 					gctx->funcs[i].fn_u.ecb(ctx, wdst,
 								wsrc);

 					wsrc += func_bytes;
 					wdst += func_bytes;
 					nbytes -= func_bytes;
 				} while (nbytes >= func_bytes);

 				if (nbytes < bsize)
 					goto done;
 			}
 		}

 done:
 		err = blkcipher_walk_done(desc, walk, nbytes);
 	}

 	glue_fpu_end(fpu_enabled);
 	return err;
 }

 int glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
 			  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 __glue_ecb_crypt_128bit(gctx, desc, &walk);
 }
 EXPORT_SYMBOL_GPL(glue_ecb_crypt_128bit);

 static unsigned int __glue_cbc_encrypt_128bit(const common_glue_func_t fn,
 					      struct blkcipher_desc *desc,
 					      struct blkcipher_walk *walk)
 {
 	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 	const unsigned int bsize = 128 / 8;
 	unsigned int nbytes = walk->nbytes;
 	u128 *src = (u128 *)walk->src.virt.addr;
 	u128 *dst = (u128 *)walk->dst.virt.addr;
 	u128 *iv = (u128 *)walk->iv;

 	do {
 		u128_xor(dst, src, iv);
 		fn(ctx, (u8 *)dst, (u8 *)dst);
 		iv = dst;

 		src += 1;
 		dst += 1;
 		nbytes -= bsize;
 	} while (nbytes >= bsize);

 	*(u128 *)walk->iv = *iv;
 	return nbytes;
 }

 int glue_cbc_encrypt_128bit(const common_glue_func_t fn,
 			    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 = __glue_cbc_encrypt_128bit(fn, desc, &walk);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_cbc_encrypt_128bit);

 static unsigned int
 __glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
 			  struct blkcipher_desc *desc,
 			  struct blkcipher_walk *walk)
 {
 	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 	const unsigned int bsize = 128 / 8;
 	unsigned int nbytes = walk->nbytes;
 	u128 *src = (u128 *)walk->src.virt.addr;
 	u128 *dst = (u128 *)walk->dst.virt.addr;
 	u128 last_iv;
 	unsigned int num_blocks, func_bytes;
 	unsigned int i;

 	/* Start of the last block. */
 	src += nbytes / bsize - 1;
 	dst += nbytes / bsize - 1;

 	last_iv = *src;

 	for (i = 0; i < gctx->num_funcs; i++) {
 		num_blocks = gctx->funcs[i].num_blocks;
 		func_bytes = bsize * num_blocks;

 		/* Process multi-block batch */
 		if (nbytes >= func_bytes) {
 			do {
 				nbytes -= func_bytes - bsize;
 				src -= num_blocks - 1;
 				dst -= num_blocks - 1;

 				gctx->funcs[i].fn_u.cbc(ctx, dst, src);

 				nbytes -= bsize;
 				if (nbytes < bsize)
 					goto done;

 				u128_xor(dst, dst, src - 1);
 				src -= 1;
 				dst -= 1;
 			} while (nbytes >= func_bytes);

 			if (nbytes < bsize)
 				goto done;
 		}
 	}

 done:
 	u128_xor(dst, dst, (u128 *)walk->iv);
 	*(u128 *)walk->iv = last_iv;

 	return nbytes;
 }

 int glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
 			    struct blkcipher_desc *desc,
 			    struct scatterlist *dst,
 			    struct scatterlist *src, unsigned int nbytes)
 {
 	const unsigned int bsize = 128 / 8;
 	bool fpu_enabled = false;
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt(desc, &walk);

 	while ((nbytes = walk.nbytes)) {
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
 					     desc, fpu_enabled, nbytes);
 		nbytes = __glue_cbc_decrypt_128bit(gctx, desc, &walk);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	glue_fpu_end(fpu_enabled);
 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_cbc_decrypt_128bit);

 static void glue_ctr_crypt_final_128bit(const common_glue_ctr_func_t fn_ctr,
 					struct blkcipher_desc *desc,
 					struct blkcipher_walk *walk)
 {
 	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 	u8 *src = (u8 *)walk->src.virt.addr;
 	u8 *dst = (u8 *)walk->dst.virt.addr;
 	unsigned int nbytes = walk->nbytes;
 	le128 ctrblk;
 	u128 tmp;

 	be128_to_le128(&ctrblk, (be128 *)walk->iv);

 	memcpy(&tmp, src, nbytes);
 	fn_ctr(ctx, &tmp, &tmp, &ctrblk);
 	memcpy(dst, &tmp, nbytes);

 	le128_to_be128((be128 *)walk->iv, &ctrblk);
 }
 EXPORT_SYMBOL_GPL(glue_ctr_crypt_final_128bit);

 static unsigned int __glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
 					    struct blkcipher_desc *desc,
 					    struct blkcipher_walk *walk)
 {
 	const unsigned int bsize = 128 / 8;
 	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 	unsigned int nbytes = walk->nbytes;
 	u128 *src = (u128 *)walk->src.virt.addr;
 	u128 *dst = (u128 *)walk->dst.virt.addr;
 	le128 ctrblk;
 	unsigned int num_blocks, func_bytes;
 	unsigned int i;

 	be128_to_le128(&ctrblk, (be128 *)walk->iv);

 	/* Process multi-block batch */
 	for (i = 0; i < gctx->num_funcs; i++) {
 		num_blocks = gctx->funcs[i].num_blocks;
 		func_bytes = bsize * num_blocks;

 		if (nbytes >= func_bytes) {
 			do {
 				gctx->funcs[i].fn_u.ctr(ctx, dst, src, &ctrblk);

 				src += num_blocks;
 				dst += num_blocks;
 				nbytes -= func_bytes;
 			} while (nbytes >= func_bytes);

 			if (nbytes < bsize)
 				goto done;
 		}
 	}

 done:
 	le128_to_be128((be128 *)walk->iv, &ctrblk);
 	return nbytes;
 }

 int glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
 			  struct blkcipher_desc *desc, struct scatterlist *dst,
 			  struct scatterlist *src, unsigned int nbytes)
 {
 	const unsigned int bsize = 128 / 8;
 	bool fpu_enabled = false;
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);
 	err = blkcipher_walk_virt_block(desc, &walk, bsize);

 	while ((nbytes = walk.nbytes) >= bsize) {
 		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
 					     desc, fpu_enabled, nbytes);
 		nbytes = __glue_ctr_crypt_128bit(gctx, desc, &walk);
 		err = blkcipher_walk_done(desc, &walk, nbytes);
 	}

 	glue_fpu_end(fpu_enabled);

 	if (walk.nbytes) {
 		glue_ctr_crypt_final_128bit(
 			gctx->funcs[gctx->num_funcs - 1].fn_u.ctr, desc, &walk);
 		err = blkcipher_walk_done(desc, &walk, 0);
 	}

 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_ctr_crypt_128bit);

 static unsigned int __glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
 					    void *ctx,
 					    struct blkcipher_desc *desc,
 					    struct blkcipher_walk *walk)
 {
 	const unsigned int bsize = 128 / 8;
 	unsigned int nbytes = walk->nbytes;
 	u128 *src = (u128 *)walk->src.virt.addr;
 	u128 *dst = (u128 *)walk->dst.virt.addr;
 	unsigned int num_blocks, func_bytes;
 	unsigned int i;

 	/* Process multi-block batch */
 	for (i = 0; i < gctx->num_funcs; i++) {
 		num_blocks = gctx->funcs[i].num_blocks;
 		func_bytes = bsize * num_blocks;

 		if (nbytes >= func_bytes) {
 			do {
 				gctx->funcs[i].fn_u.xts(ctx, dst, src,
 							(le128 *)walk->iv);

 				src += num_blocks;
 				dst += num_blocks;
 				nbytes -= func_bytes;
 			} while (nbytes >= func_bytes);

 			if (nbytes < bsize)
 				goto done;
 		}
 	}

 done:
 	return nbytes;
 }

 /* for implementations implementing faster XTS IV generator */
 int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
 			  struct blkcipher_desc *desc, struct scatterlist *dst,
 			  struct scatterlist *src, unsigned int nbytes,
 			  void (*tweak_fn)(void *ctx, u8 *dst, const u8 *src),
 			  void *tweak_ctx, void *crypt_ctx)
 {
 	const unsigned int bsize = 128 / 8;
 	bool fpu_enabled = false;
 	struct blkcipher_walk walk;
 	int err;

 	blkcipher_walk_init(&walk, dst, src, nbytes);

 	err = blkcipher_walk_virt(desc, &walk);
 	nbytes = walk.nbytes;
 	if (!nbytes)
 		return err;

 	/* set minimum length to bsize, for tweak_fn */
 	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
 				     desc, fpu_enabled,
 				     nbytes < bsize ? bsize : nbytes);

 	/* calculate first value of T */
 	tweak_fn(tweak_ctx, walk.iv, walk.iv);

 	while (nbytes) {
 		nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);

 		err = blkcipher_walk_done(desc, &walk, nbytes);
 		nbytes = walk.nbytes;
 	}

 	glue_fpu_end(fpu_enabled);

 	return err;
 }
 EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);

 void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv,
 			       common_glue_func_t fn)
 {
 	le128 ivblk = *iv;

 	/* generate next IV */
 	le128_gf128mul_x_ble(iv, &ivblk);

 	/* CC <- T xor C */
 	u128_xor(dst, src, (u128 *)&ivblk);

 	/* PP <- D(Key2,CC) */
 	fn(ctx, (u8 *)dst, (u8 *)dst);

 	/* P <- T xor PP */
 	u128_xor(dst, dst, (u128 *)&ivblk);
 }
 EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit_one);

 MODULE_LICENSE("GPL");
	/*
	* Shared glue code for 128bit block ciphers
	*
	* Copyright © 2012-2013 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 <linux/module.h>
	#include <crypto/b128ops.h>
	#include <crypto/lrw.h>
	#include <crypto/xts.h>
	#include <asm/crypto/glue_helper.h>
	#include <crypto/scatterwalk.h>

	static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
	struct blkcipher_desc *desc,
	struct blkcipher_walk *walk)
	{
	void *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = 128 / 8;
	unsigned int nbytes, i, func_bytes;
	bool fpu_enabled = false;
	int err;

	err = blkcipher_walk_virt(desc, walk);

	while ((nbytes = walk->nbytes)) {
	u8 *wsrc = walk->src.virt.addr;
	u8 *wdst = walk->dst.virt.addr;

	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
	desc, fpu_enabled, nbytes);

	for (i = 0; i < gctx->num_funcs; i++) {
	func_bytes = bsize * gctx->funcs[i].num_blocks;

	/* Process multi-block batch */
	if (nbytes >= func_bytes) {
	do {
	gctx->funcs[i].fn_u.ecb(ctx, wdst,
	wsrc);

	wsrc += func_bytes;
	wdst += func_bytes;
	nbytes -= func_bytes;
	} while (nbytes >= func_bytes);

	if (nbytes < bsize)
	goto done;
	}
	}

	done:
	err = blkcipher_walk_done(desc, walk, nbytes);
	}

	glue_fpu_end(fpu_enabled);
	return err;
	}

	int glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
	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 __glue_ecb_crypt_128bit(gctx, desc, &walk);
	}
	EXPORT_SYMBOL_GPL(glue_ecb_crypt_128bit);

	static unsigned int __glue_cbc_encrypt_128bit(const common_glue_func_t fn,
	struct blkcipher_desc *desc,
	struct blkcipher_walk *walk)
	{
	void *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = 128 / 8;
	unsigned int nbytes = walk->nbytes;
	u128 src = (u128 )walk->src.virt.addr;
	u128 dst = (u128 )walk->dst.virt.addr;
	u128 iv = (u128 )walk->iv;

	do {
	u128_xor(dst, src, iv);
	fn(ctx, (u8 )dst, (u8 )dst);
	iv = dst;

	src += 1;
	dst += 1;
	nbytes -= bsize;
	} while (nbytes >= bsize);

	(u128 )walk->iv = *iv;
	return nbytes;
	}

	int glue_cbc_encrypt_128bit(const common_glue_func_t fn,
	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 = __glue_cbc_encrypt_128bit(fn, desc, &walk);
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
	}
	EXPORT_SYMBOL_GPL(glue_cbc_encrypt_128bit);

	static unsigned int
	__glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
	struct blkcipher_desc *desc,
	struct blkcipher_walk *walk)
	{
	void *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = 128 / 8;
	unsigned int nbytes = walk->nbytes;
	u128 src = (u128 )walk->src.virt.addr;
	u128 dst = (u128 )walk->dst.virt.addr;
	u128 last_iv;
	unsigned int num_blocks, func_bytes;
	unsigned int i;

	/* Start of the last block. */
	src += nbytes / bsize - 1;
	dst += nbytes / bsize - 1;

	last_iv = *src;

	for (i = 0; i < gctx->num_funcs; i++) {
	num_blocks = gctx->funcs[i].num_blocks;
	func_bytes = bsize * num_blocks;

	/* Process multi-block batch */
	if (nbytes >= func_bytes) {
	do {
	nbytes -= func_bytes - bsize;
	src -= num_blocks - 1;
	dst -= num_blocks - 1;

	gctx->funcs[i].fn_u.cbc(ctx, dst, src);

	nbytes -= bsize;
	if (nbytes < bsize)
	goto done;

	u128_xor(dst, dst, src - 1);
	src -= 1;
	dst -= 1;
	} while (nbytes >= func_bytes);

	if (nbytes < bsize)
	goto done;
	}
	}

	done:
	u128_xor(dst, dst, (u128 *)walk->iv);
	(u128 )walk->iv = last_iv;

	return nbytes;
	}

	int glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
	struct blkcipher_desc *desc,
	struct scatterlist *dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	const unsigned int bsize = 128 / 8;
	bool fpu_enabled = false;
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
	desc, fpu_enabled, nbytes);
	nbytes = __glue_cbc_decrypt_128bit(gctx, desc, &walk);
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	glue_fpu_end(fpu_enabled);
	return err;
	}
	EXPORT_SYMBOL_GPL(glue_cbc_decrypt_128bit);

	static void glue_ctr_crypt_final_128bit(const common_glue_ctr_func_t fn_ctr,
	struct blkcipher_desc *desc,
	struct blkcipher_walk *walk)
	{
	void *ctx = crypto_blkcipher_ctx(desc->tfm);
	u8 src = (u8 )walk->src.virt.addr;
	u8 dst = (u8 )walk->dst.virt.addr;
	unsigned int nbytes = walk->nbytes;
	le128 ctrblk;
	u128 tmp;

	be128_to_le128(&ctrblk, (be128 *)walk->iv);

	memcpy(&tmp, src, nbytes);
	fn_ctr(ctx, &tmp, &tmp, &ctrblk);
	memcpy(dst, &tmp, nbytes);

	le128_to_be128((be128 *)walk->iv, &ctrblk);
	}
	EXPORT_SYMBOL_GPL(glue_ctr_crypt_final_128bit);

	static unsigned int __glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
	struct blkcipher_desc *desc,
	struct blkcipher_walk *walk)
	{
	const unsigned int bsize = 128 / 8;
	void *ctx = crypto_blkcipher_ctx(desc->tfm);
	unsigned int nbytes = walk->nbytes;
	u128 src = (u128 )walk->src.virt.addr;
	u128 dst = (u128 )walk->dst.virt.addr;
	le128 ctrblk;
	unsigned int num_blocks, func_bytes;
	unsigned int i;

	be128_to_le128(&ctrblk, (be128 *)walk->iv);

	/* Process multi-block batch */
	for (i = 0; i < gctx->num_funcs; i++) {
	num_blocks = gctx->funcs[i].num_blocks;
	func_bytes = bsize * num_blocks;

	if (nbytes >= func_bytes) {
	do {
	gctx->funcs[i].fn_u.ctr(ctx, dst, src, &ctrblk);

	src += num_blocks;
	dst += num_blocks;
	nbytes -= func_bytes;
	} while (nbytes >= func_bytes);

	if (nbytes < bsize)
	goto done;
	}
	}

	done:
	le128_to_be128((be128 *)walk->iv, &ctrblk);
	return nbytes;
	}

	int glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
	struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes)
	{
	const unsigned int bsize = 128 / 8;
	bool fpu_enabled = false;
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt_block(desc, &walk, bsize);

	while ((nbytes = walk.nbytes) >= bsize) {
	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
	desc, fpu_enabled, nbytes);
	nbytes = __glue_ctr_crypt_128bit(gctx, desc, &walk);
	err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	glue_fpu_end(fpu_enabled);

	if (walk.nbytes) {
	glue_ctr_crypt_final_128bit(
	gctx->funcs[gctx->num_funcs - 1].fn_u.ctr, desc, &walk);
	err = blkcipher_walk_done(desc, &walk, 0);
	}

	return err;
	}
	EXPORT_SYMBOL_GPL(glue_ctr_crypt_128bit);

	static unsigned int __glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
	void *ctx,
	struct blkcipher_desc *desc,
	struct blkcipher_walk *walk)
	{
	const unsigned int bsize = 128 / 8;
	unsigned int nbytes = walk->nbytes;
	u128 src = (u128 )walk->src.virt.addr;
	u128 dst = (u128 )walk->dst.virt.addr;
	unsigned int num_blocks, func_bytes;
	unsigned int i;

	/* Process multi-block batch */
	for (i = 0; i < gctx->num_funcs; i++) {
	num_blocks = gctx->funcs[i].num_blocks;
	func_bytes = bsize * num_blocks;

	if (nbytes >= func_bytes) {
	do {
	gctx->funcs[i].fn_u.xts(ctx, dst, src,
	(le128 *)walk->iv);

	src += num_blocks;
	dst += num_blocks;
	nbytes -= func_bytes;
	} while (nbytes >= func_bytes);

	if (nbytes < bsize)
	goto done;
	}
	}

	done:
	return nbytes;
	}

	/* for implementations implementing faster XTS IV generator */
	int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
	struct blkcipher_desc desc, struct scatterlist dst,
	struct scatterlist *src, unsigned int nbytes,
	void (tweak_fn)(void ctx, u8 dst, const u8 src),
	void tweak_ctx, void crypt_ctx)
	{
	const unsigned int bsize = 128 / 8;
	bool fpu_enabled = false;
	struct blkcipher_walk walk;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);

	err = blkcipher_walk_virt(desc, &walk);
	nbytes = walk.nbytes;
	if (!nbytes)
	return err;

	/* set minimum length to bsize, for tweak_fn */
	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
	desc, fpu_enabled,
	nbytes < bsize ? bsize : nbytes);

	/* calculate first value of T */
	tweak_fn(tweak_ctx, walk.iv, walk.iv);

	while (nbytes) {
	nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);

	err = blkcipher_walk_done(desc, &walk, nbytes);
	nbytes = walk.nbytes;
	}

	glue_fpu_end(fpu_enabled);

	return err;
	}
	EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);

	void glue_xts_crypt_128bit_one(void ctx, u128 dst, const u128 src, le128 iv,
	common_glue_func_t fn)
	{
	le128 ivblk = *iv;

	/* generate next IV */
	le128_gf128mul_x_ble(iv, &ivblk);

	/* CC <- T xor C */
	u128_xor(dst, src, (u128 *)&ivblk);

	/* PP <- D(Key2,CC) */
	fn(ctx, (u8 )dst, (u8 )dst);

	/* P <- T xor PP */
	u128_xor(dst, dst, (u128 *)&ivblk);
	}
	EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit_one);

	MODULE_LICENSE("GPL");