path: root/arch/x86/crypto/serpent_sse2_glue.c

/*
 * Glue Code for SSE2 assembler versions of Serpent Cipher
 *
 * Copyright (c) 2011 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
 *
 * Glue code based on aesni-intel_glue.c by:
 *  Copyright (C) 2008, Intel Corp.
 *    Author: Huang Ying <ying.huang@intel.com>
 *
 * 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 <linux/hardirq.h>
#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <crypto/algapi.h>
#include <crypto/serpent.h>
#include <crypto/cryptd.h>
#include <crypto/b128ops.h>
#include <crypto/ctr.h>
#include <crypto/lrw.h>
#include <crypto/xts.h>
#include <asm/i387.h>
#include <asm/serpent.h>
#include <crypto/scatterwalk.h>
#include <linux/workqueue.h>
#include <linux/spinlock.h>

struct async_serpent_ctx {
	struct cryptd_ablkcipher *cryptd_tfm;
};

static inline bool serpent_fpu_begin(bool fpu_enabled, unsigned int nbytes)
{
	if (fpu_enabled)
		return true;

	/* SSE2 is only used when chunk to be processed is large enough, so
	 * do not enable FPU until it is necessary.
	 */
	if (nbytes < SERPENT_BLOCK_SIZE * SERPENT_PARALLEL_BLOCKS)
		return false;

	kernel_fpu_begin();
	return true;
}

static inline void serpent_fpu_end(bool fpu_enabled)
{
	if (fpu_enabled)
		kernel_fpu_end();
}

static int ecb_crypt(struct blkcipher_desc *desc, struct blkcipher_walk *walk,
		     bool enc)
{
	bool fpu_enabled = false;
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	unsigned int nbytes;
	int err;

	err = blkcipher_walk_virt(desc, walk);
	desc->flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;

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

		fpu_enabled = serpent_fpu_begin(fpu_enabled, nbytes);

		/* Process multi-block batch */
		if (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS) {
			do {
				if (enc)
					serpent_enc_blk_xway(ctx, wdst, wsrc);
				else
					serpent_dec_blk_xway(ctx, wdst, wsrc);

				wsrc += bsize * SERPENT_PARALLEL_BLOCKS;
				wdst += bsize * SERPENT_PARALLEL_BLOCKS;
				nbytes -= bsize * SERPENT_PARALLEL_BLOCKS;
			} while (nbytes >= bsize * SERPENT_PARALLEL_BLOCKS);

			if (nbytes < bsize)
				goto done;
		}

		/* Handle leftovers */
		do {
			if (enc)
				__serpent_encrypt(ctx, wdst, wsrc);
			else
				__serpent_decrypt(ctx, wdst, wsrc);

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

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

	serpent_fpu_end(fpu_enabled);
	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, true);
}

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, false);
}

static unsigned int __cbc_encrypt(struct blkcipher_desc *desc,
				  struct blkcipher_walk *walk)
{
	struct serpent_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
	const unsigned int bsize = SERPENT_BLOCK_SIZE;
	unsigned int nbytes = walk->nbytes;
	u128 *src = (u128 *)walk->src.virt.addr;
	u128 *dst = (u128 *)walk->dst.virt.addr;
	u128 *