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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 | #include <crypto/internal/scompress.h> | |
35 | ||
36 | struct crypto842_ctx { | |
37 | void *wmem; /* working memory for compress */ | |
38 | }; | |
39 | ||
40 | static void *crypto842_alloc_ctx(struct crypto_scomp *tfm) | |
41 | { | |
42 | void *ctx; | |
43 | ||
44 | ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL); | |
45 | if (!ctx) | |
46 | return ERR_PTR(-ENOMEM); | |
47 | ||
48 | return ctx; | |
49 | } | |
50 | ||
51 | static int crypto842_init(struct crypto_tfm *tfm) | |
52 | { | |
53 | struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); | |
54 | ||
55 | ctx->wmem = crypto842_alloc_ctx(NULL); | |
56 | if (IS_ERR(ctx->wmem)) | |
57 | return -ENOMEM; | |
58 | ||
59 | return 0; | |
60 | } | |
61 | ||
62 | static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx) | |
63 | { | |
64 | kfree(ctx); | |
65 | } | |
66 | ||
67 | static void crypto842_exit(struct crypto_tfm *tfm) | |
68 | { | |
69 | struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); | |
70 | ||
71 | crypto842_free_ctx(NULL, ctx->wmem); | |
72 | } | |
73 | ||
74 | static int crypto842_compress(struct crypto_tfm *tfm, | |
75 | const u8 *src, unsigned int slen, | |
76 | u8 *dst, unsigned int *dlen) | |
77 | { | |
78 | struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm); | |
79 | ||
80 | return sw842_compress(src, slen, dst, dlen, ctx->wmem); | |
81 | } | |
82 | ||
83 | static int crypto842_scompress(struct crypto_scomp *tfm, | |
84 | const u8 *src, unsigned int slen, | |
85 | u8 *dst, unsigned int *dlen, void *ctx) | |
86 | { | |
87 | return sw842_compress(src, slen, dst, dlen, ctx); | |
88 | } | |
89 | ||
90 | static int crypto842_decompress(struct crypto_tfm *tfm, | |
91 | const u8 *src, unsigned int slen, | |
92 | u8 *dst, unsigned int *dlen) | |
93 | { | |
94 | return sw842_decompress(src, slen, dst, dlen); | |
95 | } | |
96 | ||
97 | static int crypto842_sdecompress(struct crypto_scomp *tfm, | |
98 | const u8 *src, unsigned int slen, | |
99 | u8 *dst, unsigned int *dlen, void *ctx) | |
100 | { | |
101 | return sw842_decompress(src, slen, dst, dlen); | |
102 | } | |
103 | ||
104 | static struct crypto_alg alg = { | |
105 | .cra_name = "842", | |
106 | .cra_driver_name = "842-generic", | |
107 | .cra_priority = 100, | |
108 | .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, | |
109 | .cra_ctxsize = sizeof(struct crypto842_ctx), | |
110 | .cra_module = THIS_MODULE, | |
111 | .cra_init = crypto842_init, | |
112 | .cra_exit = crypto842_exit, | |
113 | .cra_u = { .compress = { | |
114 | .coa_compress = crypto842_compress, | |
115 | .coa_decompress = crypto842_decompress } } | |
116 | }; | |
117 | ||
118 | static struct scomp_alg scomp = { | |
119 | .alloc_ctx = crypto842_alloc_ctx, | |
120 | .free_ctx = crypto842_free_ctx, | |
121 | .compress = crypto842_scompress, | |
122 | .decompress = crypto842_sdecompress, | |
123 | .base = { | |
124 | .cra_name = "842", | |
125 | .cra_driver_name = "842-scomp", | |
126 | .cra_priority = 100, | |
127 | .cra_module = THIS_MODULE, | |
128 | } | |
129 | }; | |
130 | ||
131 | static int __init crypto842_mod_init(void) | |
132 | { | |
133 | int ret; | |
134 | ||
135 | ret = crypto_register_alg(&alg); | |
136 | if (ret) | |
137 | return ret; | |
138 | ||
139 | ret = crypto_register_scomp(&scomp); | |
140 | if (ret) { | |
141 | crypto_unregister_alg(&alg); | |
142 | return ret; | |
143 | } | |
144 | ||
145 | return ret; | |
146 | } | |
147 | module_init(crypto842_mod_init); | |
148 | ||
149 | static void __exit crypto842_mod_exit(void) | |
150 | { | |
151 | crypto_unregister_alg(&alg); | |
152 | crypto_unregister_scomp(&scomp); | |
153 | } | |
154 | module_exit(crypto842_mod_exit); | |
155 | ||
156 | MODULE_LICENSE("GPL"); | |
157 | MODULE_DESCRIPTION("842 Software Compression Algorithm"); | |
158 | MODULE_ALIAS_CRYPTO("842"); | |
159 | MODULE_ALIAS_CRYPTO("842-generic"); | |
160 | MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>"); |