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183 lines
4.6 KiB
C
183 lines
4.6 KiB
C
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/*
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* Cryptographic API for the 842 compression algorithm.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* Copyright (C) IBM Corporation, 2011
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*
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* Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
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* Seth Jennings <sjenning@linux.vnet.ibm.com>
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/crypto.h>
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#include <linux/vmalloc.h>
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#include <linux/nx842.h>
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#include <linux/lzo.h>
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#include <linux/timer.h>
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static int nx842_uselzo;
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struct nx842_ctx {
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void *nx842_wmem; /* working memory for 842/lzo */
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};
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enum nx842_crypto_type {
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NX842_CRYPTO_TYPE_842,
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NX842_CRYPTO_TYPE_LZO
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};
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#define NX842_SENTINEL 0xdeadbeef
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struct nx842_crypto_header {
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unsigned int sentinel; /* debug */
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enum nx842_crypto_type type;
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};
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static int nx842_init(struct crypto_tfm *tfm)
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{
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struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
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int wmemsize;
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wmemsize = max_t(int, nx842_get_workmem_size(), LZO1X_MEM_COMPRESS);
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ctx->nx842_wmem = kmalloc(wmemsize, GFP_NOFS);
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if (!ctx->nx842_wmem)
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return -ENOMEM;
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return 0;
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}
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static void nx842_exit(struct crypto_tfm *tfm)
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{
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struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
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kfree(ctx->nx842_wmem);
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}
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static void nx842_reset_uselzo(unsigned long data)
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{
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nx842_uselzo = 0;
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}
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static DEFINE_TIMER(failover_timer, nx842_reset_uselzo, 0, 0);
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static int nx842_crypto_compress(struct crypto_tfm *tfm, const u8 *src,
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unsigned int slen, u8 *dst, unsigned int *dlen)
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{
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struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
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struct nx842_crypto_header *hdr;
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unsigned int tmp_len = *dlen;
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size_t lzodlen; /* needed for lzo */
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int err;
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*dlen = 0;
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hdr = (struct nx842_crypto_header *)dst;
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hdr->sentinel = NX842_SENTINEL; /* debug */
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dst += sizeof(struct nx842_crypto_header);
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tmp_len -= sizeof(struct nx842_crypto_header);
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lzodlen = tmp_len;
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if (likely(!nx842_uselzo)) {
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err = nx842_compress(src, slen, dst, &tmp_len, ctx->nx842_wmem);
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if (likely(!err)) {
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hdr->type = NX842_CRYPTO_TYPE_842;
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*dlen = tmp_len + sizeof(struct nx842_crypto_header);
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return 0;
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}
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/* hardware failed */
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nx842_uselzo = 1;
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/* set timer to check for hardware again in 1 second */
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mod_timer(&failover_timer, jiffies + msecs_to_jiffies(1000));
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}
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/* no hardware, use lzo */
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err = lzo1x_1_compress(src, slen, dst, &lzodlen, ctx->nx842_wmem);
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if (err != LZO_E_OK)
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return -EINVAL;
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hdr->type = NX842_CRYPTO_TYPE_LZO;
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*dlen = lzodlen + sizeof(struct nx842_crypto_header);
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return 0;
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}
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static int nx842_crypto_decompress(struct crypto_tfm *tfm, const u8 *src,
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unsigned int slen, u8 *dst, unsigned int *dlen)
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{
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struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
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struct nx842_crypto_header *hdr;
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unsigned int tmp_len = *dlen;
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size_t lzodlen; /* needed for lzo */
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int err;
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*dlen = 0;
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hdr = (struct nx842_crypto_header *)src;
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if (unlikely(hdr->sentinel != NX842_SENTINEL))
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return -EINVAL;
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src += sizeof(struct nx842_crypto_header);
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slen -= sizeof(struct nx842_crypto_header);
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if (likely(hdr->type == NX842_CRYPTO_TYPE_842)) {
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err = nx842_decompress(src, slen, dst, &tmp_len,
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ctx->nx842_wmem);
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if (err)
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return -EINVAL;
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*dlen = tmp_len;
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} else if (hdr->type == NX842_CRYPTO_TYPE_LZO) {
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lzodlen = tmp_len;
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err = lzo1x_decompress_safe(src, slen, dst, &lzodlen);
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if (err != LZO_E_OK)
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return -EINVAL;
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*dlen = lzodlen;
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} else
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return -EINVAL;
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return 0;
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}
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static struct crypto_alg alg = {
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.cra_name = "842",
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.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
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.cra_ctxsize = sizeof(struct nx842_ctx),
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.cra_module = THIS_MODULE,
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.cra_init = nx842_init,
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.cra_exit = nx842_exit,
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.cra_u = { .compress = {
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.coa_compress = nx842_crypto_compress,
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.coa_decompress = nx842_crypto_decompress } }
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};
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static int __init nx842_mod_init(void)
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{
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del_timer(&failover_timer);
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return crypto_register_alg(&alg);
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}
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static void __exit nx842_mod_exit(void)
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{
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crypto_unregister_alg(&alg);
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}
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module_init(nx842_mod_init);
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module_exit(nx842_mod_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("842 Compression Algorithm");
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