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/*
* Cryptographic API for the 842 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.
*
* 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
*
* Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
* Seth Jennings <sjenning@linux.vnet.ibm.com>
*/
#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
struct nx842_crypto_header {
unsigned int sentinel; /* debug */
enum nx842_crypto_type type;
};
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)
{
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;
/* set timer to check for hardware again in 1 second */
mod_timer(&failover_timer, jiffies + msecs_to_jiffies(1000));
}
/* 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)
{
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;
}
static struct crypto_alg alg = {
.cra_name = "842",
.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
.cra_ctxsize = sizeof(struct nx842_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 } }
};
static int __init nx842_mod_init(void)
{
del_timer(&failover_timer);
return crypto_register_alg(&alg);
}
static void __exit nx842_mod_exit(void)
{
crypto_unregister_alg(&alg);
}
module_init(nx842_mod_init);
module_exit(nx842_mod_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("842 Compression Algorithm");
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