LXR linux/crypto/842.c

   1/*
   2 * Cryptographic API for the 842 software compression algorithm.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License as published by
   6 * the Free Software Foundation; either version 2 of the License, or
   7 * (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * Copyright (C) IBM Corporation, 2011-2015
  15 *
  16 * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
  17 *                   Seth Jennings <sjenning@linux.vnet.ibm.com>
  18 *
  19 * Rewrite: Dan Streetman <ddstreet@ieee.org>
  20 *
  21 * This is the software implementation of compression and decompression using
  22 * the 842 format.  This uses the software 842 library at lib/842/ which is
  23 * only a reference implementation, and is very, very slow as compared to other
  24 * software compressors.  You probably do not want to use this software
  25 * compression.  If you have access to the PowerPC 842 compression hardware, you
  26 * want to use the 842 hardware compression interface, which is at:
  27 * drivers/crypto/nx/nx-842-crypto.c
  28 */
  29
  30#include <linux/init.h>
  31#include <linux/module.h>
  32#include <linux/crypto.h>
  33#include <linux/sw842.h>
  34
  35struct crypto842_ctx {
  36        char wmem[SW842_MEM_COMPRESS];  /* working memory for compress */
  37};
  38
  39static int crypto842_compress(struct crypto_tfm *tfm,
  40                              const u8 *src, unsigned int slen,
  41                              u8 *dst, unsigned int *dlen)
  42{
  43        struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
  44
  45        return sw842_compress(src, slen, dst, dlen, ctx->wmem);
  46}
  47
  48static int crypto842_decompress(struct crypto_tfm *tfm,
  49                                const u8 *src, unsigned int slen,
  50                                u8 *dst, unsigned int *dlen)
  51{
  52        return sw842_decompress(src, slen, dst, dlen);
  53}
  54
  55static struct crypto_alg alg = {
  56        .cra_name               = "842",
  57        .cra_driver_name        = "842-generic",
  58        .cra_priority           = 100,
  59        .cra_flags              = CRYPTO_ALG_TYPE_COMPRESS,
  60        .cra_ctxsize            = sizeof(struct crypto842_ctx),
  61        .cra_module             = THIS_MODULE,
  62        .cra_u                  = { .compress = {
  63        .coa_compress           = crypto842_compress,
  64        .coa_decompress         = crypto842_decompress } }
  65};
  66
  67static int __init crypto842_mod_init(void)
  68{
  69        return crypto_register_alg(&alg);
  70}
  71module_init(crypto842_mod_init);
  72
  73static void __exit crypto842_mod_exit(void)
  74{
  75        crypto_unregister_alg(&alg);
  76}
  77module_exit(crypto842_mod_exit);
  78
  79MODULE_LICENSE("GPL");
  80MODULE_DESCRIPTION("842 Software Compression Algorithm");
  81MODULE_ALIAS_CRYPTO("842");
  82MODULE_ALIAS_CRYPTO("842-generic");
  83MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
  84