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
27struct crypto842_ctx {
28 void *wmem; /* working memory for compress */
29};
30
31static 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(error: -ENOMEM);
38
39 return ctx;
40}
41
42static 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(ptr: ctx->wmem))
48 return -ENOMEM;
49
50 return 0;
51}
52
53static void crypto842_free_ctx(struct crypto_scomp *tfm, void *ctx)
54{
55 kfree(objp: ctx);
56}
57
58static void crypto842_exit(struct crypto_tfm *tfm)
59{
60 struct crypto842_ctx *ctx = crypto_tfm_ctx(tfm);
61
62 crypto842_free_ctx(NULL, ctx: ctx->wmem);
63}
64
65static 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, srclen: slen, dst, destlen: dlen, wmem: ctx->wmem);
72}
73
74static 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, srclen: slen, dst, destlen: dlen, wmem: ctx);
79}
80
81static 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, srclen: slen, dst, destlen: dlen);
86}
87
88static 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, srclen: slen, dst, destlen: dlen);
93}
94
95static 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
109static 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
122static int __init crypto842_mod_init(void)
123{
124 int ret;
125
126 ret = crypto_register_alg(alg: &alg);
127 if (ret)
128 return ret;
129
130 ret = crypto_register_scomp(alg: &scomp);
131 if (ret) {
132 crypto_unregister_alg(alg: &alg);
133 return ret;
134 }
135
136 return ret;
137}
138subsys_initcall(crypto842_mod_init);
139
140static void __exit crypto842_mod_exit(void)
141{
142 crypto_unregister_alg(alg: &alg);
143 crypto_unregister_scomp(alg: &scomp);
144}
145module_exit(crypto842_mod_exit);
146
147MODULE_LICENSE("GPL");
148MODULE_DESCRIPTION("842 Software Compression Algorithm");
149MODULE_ALIAS_CRYPTO("842");
150MODULE_ALIAS_CRYPTO("842-generic");
151MODULE_AUTHOR("Dan Streetman <ddstreet@ieee.org>");
152

source code of linux/crypto/842.c