Commit 2062c5b6 authored by Dan Streetman's avatar Dan Streetman Committed by Herbert Xu
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crypto: 842 - change 842 alg to use software 



Change the crypto 842 compression alg to use the software 842 compression
and decompression library.  Add the crypto driver_name as "842-generic".
Remove the fallback to LZO compression.

Previously, this crypto compression alg attemped 842 compression using
PowerPC hardware, and fell back to LZO compression and decompression if
the 842 PowerPC hardware was unavailable or failed.  This should not
fall back to any other compression method, however; users of this crypto
compression alg can fallback if desired, and transparent fallback tricks
callers into thinking they are getting 842 compression when they actually
get LZO compression - the failure of the 842 hardware should not be
transparent to the caller.

The crypto compression alg for a hardware device also should not be located
in crypto/ so this is now a software-only implementation that uses the 842
software compression/decompression library.

Signed-off-by: default avatarDan Streetman <ddstreet@ieee.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 2da572c9

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -4864,6 +4864,7 @@ S: Supported 
F:	drivers/crypto/nx/nx-842.c

F:	include/linux/nx842.h

F:	include/linux/sw842.h

F:	crypto/842.c

F:	lib/842/



IBM Power Linux RAID adapter

crypto/842.c

+37 −137
Original line number Diff line number Diff line 
/*

 * Cryptographic API for the 842 compression algorithm.

 * Cryptographic API for the 842 software compression algorithm.

 *

 * 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
@@ -11,173 +11,73 @@ 
 * 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, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 * Copyright (C) IBM Corporation, 2011-2015

 *

 * Copyright (C) IBM Corporation, 2011

 *

 * Authors: Robert Jennings <rcj@linux.vnet.ibm.com>

 * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>

 *                   Seth Jennings <sjenning@linux.vnet.ibm.com>

 *

 * Rewrite: Dan Streetman <ddstreet@ieee.org>

 *

 * This is the software implementation of compression and decompression using

 * the 842 format.  This uses the software 842 library at lib/842/ which is

 * only a reference implementation, and is very, very slow as compared to other

 * software compressors.  You probably do not want to use this software

 * compression.  If you have access to the PowerPC 842 compression hardware, you

 * want to use the 842 hardware compression interface, which is at:

 * drivers/crypto/nx/nx-842-crypto.c

 */



#include <linux/init.h>

#include <linux/module.h>

#include <linux/crypto.h>

#include <linux/vmalloc.h>

#include <linux/nx842.h>

#include <linux/lzo.h>

#include <linux/timer.h>



static int nx842_uselzo;



struct nx842_ctx {

	void *nx842_wmem; /* working memory for 842/lzo */

};



enum nx842_crypto_type {

	NX842_CRYPTO_TYPE_842,

	NX842_CRYPTO_TYPE_LZO

};



#define NX842_SENTINEL 0xdeadbeef

#include <linux/sw842.h>



struct nx842_crypto_header {

	unsigned int sentinel; /* debug */

	enum nx842_crypto_type type;

struct crypto842_ctx {

	char wmem[SW842_MEM_COMPRESS];	/* working memory for compress */

};



static int nx842_init(struct crypto_tfm *tfm)

{

	struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);

	int wmemsize;



	wmemsize = max_t(int, nx842_get_workmem_size(), LZO1X_MEM_COMPRESS);

	ctx->nx842_wmem = kmalloc(wmemsize, GFP_NOFS);

	if (!ctx->nx842_wmem)

		return -ENOMEM;



	return 0;

}



static void nx842_exit(struct crypto_tfm *tfm)

{

	struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);



	kfree(ctx->nx842_wmem);

}



static void nx842_reset_uselzo(unsigned long data)

static int crypto842_compress(struct crypto_tfm *tfm,

			      const u8 *src, unsigned int slen,

			      u8 *dst, unsigned int *dlen)

{

	nx842_uselzo = 0;

}



static DEFINE_TIMER(failover_timer, nx842_reset_uselzo, 0, 0);



static int nx842_crypto_compress(struct crypto_tfm *tfm, const u8 *src,

			    unsigned int slen, u8 *dst, unsigned int *dlen)

{

	struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);

	struct nx842_crypto_header *hdr;

	unsigned int tmp_len = *dlen;

	size_t lzodlen; /* needed for lzo */

	int err;



	*dlen = 0;

	hdr = (struct nx842_crypto_header *)dst;

	hdr->sentinel = NX842_SENTINEL; /* debug */

	dst += sizeof(struct nx842_crypto_header);

	tmp_len -= sizeof(struct nx842_crypto_header);

	lzodlen = tmp_len;



	if (likely(!nx842_uselzo)) {

		err = nx842_compress(src, slen, dst, &tmp_len, ctx->nx842_wmem);



		if (likely(!err)) {

			hdr->type = NX842_CRYPTO_TYPE_842;

			*dlen = tmp_len + sizeof(struct nx842_crypto_header);

			return 0;

		}



		/* hardware failed */

		nx842_uselzo = 1;

	struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);



		/* set timer to check for hardware again in 1 second */

		mod_timer(&failover_timer, jiffies + msecs_to_jiffies(1000));

	return sw842_compress(src, slen, dst, dlen, ctx->wmem);

}



	/* no hardware, use lzo */

	err = lzo1x_1_compress(src, slen, dst, &lzodlen, ctx->nx842_wmem);

	if (err != LZO_E_OK)

		return -EINVAL;



	hdr->type = NX842_CRYPTO_TYPE_LZO;

	*dlen = lzodlen + sizeof(struct nx842_crypto_header);

	return 0;

}



static int nx842_crypto_decompress(struct crypto_tfm *tfm, const u8 *src,

			      unsigned int slen, u8 *dst, unsigned int *dlen)

static int crypto842_decompress(struct crypto_tfm *tfm,

				const u8 *src, unsigned int slen,

				u8 *dst, unsigned int *dlen)

{

	struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);

	struct nx842_crypto_header *hdr;

	unsigned int tmp_len = *dlen;

	size_t lzodlen; /* needed for lzo */

	int err;



	*dlen = 0;

	hdr = (struct nx842_crypto_header *)src;



	if (unlikely(hdr->sentinel != NX842_SENTINEL))

		return -EINVAL;



	src += sizeof(struct nx842_crypto_header);

	slen -= sizeof(struct nx842_crypto_header);



	if (likely(hdr->type == NX842_CRYPTO_TYPE_842)) {

		err = nx842_decompress(src, slen, dst, &tmp_len,

			ctx->nx842_wmem);

		if (err)

			return -EINVAL;

		*dlen = tmp_len;

	} else if (hdr->type == NX842_CRYPTO_TYPE_LZO) {

		lzodlen = tmp_len;

		err = lzo1x_decompress_safe(src, slen, dst, &lzodlen);

		if (err != LZO_E_OK)

			return -EINVAL;

		*dlen = lzodlen;

	} else

		return -EINVAL;



	return 0;

	return sw842_decompress(src, slen, dst, dlen);

}



static struct crypto_alg alg = {

	.cra_name		= "842",

	.cra_driver_name	= "842-generic",

	.cra_priority		= 100,

	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,

	.cra_ctxsize		= sizeof(struct nx842_ctx),

	.cra_ctxsize		= sizeof(struct crypto842_ctx),

	.cra_module		= THIS_MODULE,

	.cra_init		= nx842_init,

	.cra_exit		= nx842_exit,

	.cra_u			= { .compress = {

	.coa_compress		= nx842_crypto_compress,

	.coa_decompress		= nx842_crypto_decompress } }

	.coa_compress		= crypto842_compress,

	.coa_decompress		= crypto842_decompress } }

};



static int __init nx842_mod_init(void)

static int __init crypto842_mod_init(void)

{

	del_timer(&failover_timer);

	return crypto_register_alg(&alg);

}

module_init(crypto842_mod_init);



static void __exit nx842_mod_exit(void)

static void __exit crypto842_mod_exit(void)

{

	crypto_unregister_alg(&alg);

}



module_init(nx842_mod_init);

module_exit(nx842_mod_exit);

module_exit(crypto842_mod_exit);



MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("842 Compression Algorithm");

MODULE_DESCRIPTION("842 Software Compression Algorithm");

MODULE_ALIAS_CRYPTO("842");

MODULE_ALIAS_CRYPTO("842-generic");

MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");

crypto/Kconfig

+3 −4
Original line number Diff line number Diff line
@@ -1412,10 +1412,9 @@ config CRYPTO_LZO 


config CRYPTO_842

	tristate "842 compression algorithm"

	depends on CRYPTO_DEV_NX_COMPRESS

	# 842 uses lzo if the hardware becomes unavailable

	select LZO_COMPRESS

	select LZO_DECOMPRESS

	select CRYPTO_ALGAPI

	select 842_COMPRESS

	select 842_DECOMPRESS

	help

	  This is the 842 algorithm.

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