161 строка
4.2 KiB
C
161 строка
4.2 KiB
C
/*
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* Cryptographic API for the 842 software 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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* Copyright (C) IBM Corporation, 2011-2015
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*
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* Original 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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* Rewrite: Dan Streetman <ddstreet@ieee.org>
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*
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* This is the software implementation of compression and decompression using
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* the 842 format. This uses the software 842 library at lib/842/ which is
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* only a reference implementation, and is very, very slow as compared to other
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* software compressors. You probably do not want to use this software
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* compression. If you have access to the PowerPC 842 compression hardware, you
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* want to use the 842 hardware compression interface, which is at:
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* drivers/crypto/nx/nx-842-crypto.c
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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/sw842.h>
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#include <crypto/internal/scompress.h>
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struct crypto842_ctx {
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void *wmem; /* working memory for compress */
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};
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static void *crypto842_alloc_ctx(struct crypto_scomp *tfm)
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{
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void *ctx;
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ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
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if (!ctx)
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return ERR_PTR(-ENOMEM);
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return ctx;
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}
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static int crypto842_init(struct crypto_tfm *tfm)
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{
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struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
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ctx->wmem = crypto842_alloc_ctx(NULL);
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if (IS_ERR(ctx->wmem))
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return -ENOMEM;
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return 0;
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}
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static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
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{
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kfree(ctx);
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}
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static void crypto842_exit(struct crypto_tfm *tfm)
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{
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struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
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crypto842_free_ctx(NULL, ctx->wmem);
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}
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static int crypto842_compress(struct crypto_tfm *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen)
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{
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struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
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return sw842_compress(src, slen, dst, dlen, ctx->wmem);
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}
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static int crypto842_scompress(struct crypto_scomp *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen, void *ctx)
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{
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return sw842_compress(src, slen, dst, dlen, ctx);
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}
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static int crypto842_decompress(struct crypto_tfm *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen)
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{
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return sw842_decompress(src, slen, dst, dlen);
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}
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static int crypto842_sdecompress(struct crypto_scomp *tfm,
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const u8 *src, unsigned int slen,
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u8 *dst, unsigned int *dlen, void *ctx)
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{
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return sw842_decompress(src, slen, dst, dlen);
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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_driver_name = "842-generic",
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.cra_priority = 100,
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.cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
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.cra_ctxsize = sizeof(struct crypto842_ctx),
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.cra_module = THIS_MODULE,
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.cra_init = crypto842_init,
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.cra_exit = crypto842_exit,
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.cra_u = { .compress = {
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.coa_compress = crypto842_compress,
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.coa_decompress = crypto842_decompress } }
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};
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static struct scomp_alg scomp = {
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.alloc_ctx = crypto842_alloc_ctx,
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.free_ctx = crypto842_free_ctx,
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.compress = crypto842_scompress,
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.decompress = crypto842_sdecompress,
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.base = {
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.cra_name = "842",
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.cra_driver_name = "842-scomp",
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.cra_priority = 100,
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.cra_module = THIS_MODULE,
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}
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};
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static int __init crypto842_mod_init(void)
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{
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int ret;
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ret = crypto_register_alg(&alg);
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if (ret)
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return ret;
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ret = crypto_register_scomp(&scomp);
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if (ret) {
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crypto_unregister_alg(&alg);
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return ret;
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}
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return ret;
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}
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module_init(crypto842_mod_init);
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static void __exit crypto842_mod_exit(void)
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{
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crypto_unregister_alg(&alg);
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crypto_unregister_scomp(&scomp);
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}
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module_exit(crypto842_mod_exit);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("842 Software Compression Algorithm");
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MODULE_ALIAS_CRYPTO("842");
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MODULE_ALIAS_CRYPTO("842-generic");
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MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
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