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(error: -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(ptr: 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(objp: 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: 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, srclen: slen, dst, destlen: dlen, wmem: 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, srclen: slen, dst, destlen: dlen, wmem: 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, srclen: slen, dst, destlen: 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, srclen: slen, dst, destlen: 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: &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 | } |
138 | subsys_initcall(crypto842_mod_init); |
139 | |
140 | static void __exit crypto842_mod_exit(void) |
141 | { |
142 | crypto_unregister_alg(alg: &alg); |
143 | crypto_unregister_scomp(alg: &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 | |