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
35 struct crypto842_ctx {
36 char wmem[SW842_MEM_COMPRESS]; /* working memory for compress */
37 };
38
crypto842_compress(struct crypto_tfm * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen)39 static 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
crypto842_decompress(struct crypto_tfm * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen)48 static 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
55 static 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
crypto842_mod_init(void)67 static int __init crypto842_mod_init(void)
68 {
69 return crypto_register_alg(&alg);
70 }
71 module_init(crypto842_mod_init);
72
crypto842_mod_exit(void)73 static void __exit crypto842_mod_exit(void)
74 {
75 crypto_unregister_alg(&alg);
76 }
77 module_exit(crypto842_mod_exit);
78
79 MODULE_LICENSE("GPL");
80 MODULE_DESCRIPTION("842 Software Compression Algorithm");
81 MODULE_ALIAS_CRYPTO("842");
82 MODULE_ALIAS_CRYPTO("842-generic");
83 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
84