linux/crypto/842.c

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/*
* 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
* 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.
*
* Copyright (C) IBM Corporation, 2011-2015
*
* 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/sw842.h>
#include <crypto/internal/scompress.h>
struct crypto842_ctx {
void *wmem; /* working memory for compress */
};
static void *crypto842_alloc_ctx(struct crypto_scomp *tfm)
{
void *ctx;
ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
if (!ctx)
return ERR_PTR(-ENOMEM);
return ctx;
}
static int crypto842_init(struct crypto_tfm *tfm)
{
struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->wmem = crypto842_alloc_ctx(NULL);
if (IS_ERR(ctx->wmem))
return -ENOMEM;
return 0;
}
static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
{
kfree(ctx);
}
static void crypto842_exit(struct crypto_tfm *tfm)
{
struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
crypto842_free_ctx(NULL, ctx->wmem);
}
static int crypto842_compress(struct crypto_tfm *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen)
{
struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
return sw842_compress(src, slen, dst, dlen, ctx->wmem);
}
static int crypto842_scompress(struct crypto_scomp *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen, void *ctx)
{
return sw842_compress(src, slen, dst, dlen, ctx);
}
static int crypto842_decompress(struct crypto_tfm *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen)
{
return sw842_decompress(src, slen, dst, dlen);
}
static int crypto842_sdecompress(struct crypto_scomp *tfm,
const u8 *src, unsigned int slen,
u8 *dst, unsigned int *dlen, void *ctx)
{
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 crypto842_ctx),
.cra_module = THIS_MODULE,
.cra_init = crypto842_init,
.cra_exit = crypto842_exit,
.cra_u = { .compress = {
.coa_compress = crypto842_compress,
.coa_decompress = crypto842_decompress } }
};
static struct scomp_alg scomp = {
.alloc_ctx = crypto842_alloc_ctx,
.free_ctx = crypto842_free_ctx,
.compress = crypto842_scompress,
.decompress = crypto842_sdecompress,
.base = {
.cra_name = "842",
.cra_driver_name = "842-scomp",
.cra_priority = 100,
.cra_module = THIS_MODULE,
}
};
static int __init crypto842_mod_init(void)
{
int ret;
ret = crypto_register_alg(&alg);
if (ret)
return ret;
ret = crypto_register_scomp(&scomp);
if (ret) {
crypto_unregister_alg(&alg);
return ret;
}
return ret;
}
module_init(crypto842_mod_init);
static void __exit crypto842_mod_exit(void)
{
crypto_unregister_alg(&alg);
crypto_unregister_scomp(&scomp);
}
module_exit(crypto842_mod_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("842 Software Compression Algorithm");
MODULE_ALIAS_CRYPTO("842");
MODULE_ALIAS_CRYPTO("842-generic");
MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");