1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Cryptographic API for the 842 software compression algorithm.
4 *
5 * Copyright (C) IBM Corporation, 2011-2015
6 *
7 * Original Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
8 * Seth Jennings <sjenning@linux.vnet.ibm.com>
9 *
10 * Rewrite: Dan Streetman <ddstreet@ieee.org>
11 *
12 * This is the software implementation of compression and decompression using
13 * the 842 format. This uses the software 842 library at lib/842/ which is
14 * only a reference implementation, and is very, very slow as compared to other
15 * software compressors. You probably do not want to use this software
16 * compression. If you have access to the PowerPC 842 compression hardware, you
17 * want to use the 842 hardware compression interface, which is at:
18 * drivers/crypto/nx/nx-842-crypto.c
19 */
20
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/crypto.h>
24 #include <linux/sw842.h>
25 #include <crypto/internal/scompress.h>
26
27 struct crypto842_ctx {
28 void *wmem; /* working memory for compress */
29 };
30
31 static void *crypto842_alloc_ctx(struct crypto_scomp *tfm)
32 {
33 void *ctx;
34
35 ctx = kmalloc(SW842_MEM_COMPRESS, GFP_KERNEL);
36 if (!ctx)
37 return ERR_PTR(-ENOMEM);
38
39 return ctx;
40 }
41
42 static int crypto842_init(struct crypto_tfm *tfm)
43 {
44 struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
45
46 ctx->wmem = crypto842_alloc_ctx(NULL);
47 if (IS_ERR(ctx->wmem))
48 return -ENOMEM;
49
50 return 0;
51 }
52
53 static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
54 {
55 kfree(ctx);
56 }
57
58 static void crypto842_exit(struct crypto_tfm *tfm)
59 {
60 struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
61
62 crypto842_free_ctx(NULL, ctx->wmem);
63 }
64
65 static int crypto842_compress(struct crypto_tfm *tfm,
66 const u8 *src, unsigned int slen,
67 u8 *dst, unsigned int *dlen)
68 {
69 struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
70
71 return sw842_compress(src, slen, dst, dlen, ctx->wmem);
72 }
73
74 static int crypto842_scompress(struct crypto_scomp *tfm,
75 const u8 *src, unsigned int slen,
76 u8 *dst, unsigned int *dlen, void *ctx)
77 {
78 return sw842_compress(src, slen, dst, dlen, ctx);
79 }
80
81 static int crypto842_decompress(struct crypto_tfm *tfm,
82 const u8 *src, unsigned int slen,
83 u8 *dst, unsigned int *dlen)
84 {
85 return sw842_decompress(src, slen, dst, dlen);
86 }
87
88 static int crypto842_sdecompress(struct crypto_scomp *tfm,
89 const u8 *src, unsigned int slen,
90 u8 *dst, unsigned int *dlen, void *ctx)
91 {
92 return sw842_decompress(src, slen, dst, dlen);
93 }
94
95 static struct crypto_alg alg = {
96 .cra_name = "842",
97 .cra_driver_name = "842-generic",
98 .cra_priority = 100,
99 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
100 .cra_ctxsize = sizeof(struct crypto842_ctx),
101 .cra_module = THIS_MODULE,
102 .cra_init = crypto842_init,
103 .cra_exit = crypto842_exit,
104 .cra_u = { .compress = {
105 .coa_compress = crypto842_compress,
106 .coa_decompress = crypto842_decompress } }
107 };
108
109 static struct scomp_alg scomp = {
110 .alloc_ctx = crypto842_alloc_ctx,
111 .free_ctx = crypto842_free_ctx,
112 .compress = crypto842_scompress,
113 .decompress = crypto842_sdecompress,
114 .base = {
115 .cra_name = "842",
116 .cra_driver_name = "842-scomp",
117 .cra_priority = 100,
118 .cra_module = THIS_MODULE,
119 }
120 };
121
122 static int __init crypto842_mod_init(void)
123 {
124 int ret;
125
126 ret = crypto_register_alg(&alg);
127 if (ret)
128 return ret;
129
130 ret = crypto_register_scomp(&scomp);
131 if (ret) {
132 crypto_unregister_alg(&alg);
133 return ret;
134 }
135
136 return ret;
137 }
138 subsys_initcall(crypto842_mod_init);
139
140 static void __exit crypto842_mod_exit(void)
141 {
142 crypto_unregister_alg(&alg);
143 crypto_unregister_scomp(&scomp);
144 }
145 module_exit(crypto842_mod_exit);
146
147 MODULE_LICENSE("GPL");
148 MODULE_DESCRIPTION("842 Software Compression Algorithm");
149 MODULE_ALIAS_CRYPTO("842");
150 MODULE_ALIAS_CRYPTO("842-generic");
151 MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
152
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