1 /*
2 * Cryptographic API for the 842 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 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17 *
18 * Copyright (C) IBM Corporation, 2011
19 *
20 * Authors: Robert Jennings <rcj@linux.vnet.ibm.com>
21 * Seth Jennings <sjenning@linux.vnet.ibm.com>
22 */
23
24 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/crypto.h>
27 #include <linux/vmalloc.h>
28 #include <linux/nx842.h>
29 #include <linux/lzo.h>
30 #include <linux/timer.h>
31
32 static int nx842_uselzo;
33
34 struct nx842_ctx {
35 void *nx842_wmem; /* working memory for 842/lzo */
36 };
37
38 enum nx842_crypto_type {
39 NX842_CRYPTO_TYPE_842,
40 NX842_CRYPTO_TYPE_LZO
41 };
42
43 #define NX842_SENTINEL 0xdeadbeef
44
45 struct nx842_crypto_header {
46 unsigned int sentinel; /* debug */
47 enum nx842_crypto_type type;
48 };
49
nx842_init(struct crypto_tfm * tfm)50 static int nx842_init(struct crypto_tfm *tfm)
51 {
52 struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
53 int wmemsize;
54
55 wmemsize = max_t(int, nx842_get_workmem_size(), LZO1X_MEM_COMPRESS);
56 ctx->nx842_wmem = kmalloc(wmemsize, GFP_NOFS);
57 if (!ctx->nx842_wmem)
58 return -ENOMEM;
59
60 return 0;
61 }
62
nx842_exit(struct crypto_tfm * tfm)63 static void nx842_exit(struct crypto_tfm *tfm)
64 {
65 struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
66
67 kfree(ctx->nx842_wmem);
68 }
69
nx842_reset_uselzo(unsigned long data)70 static void nx842_reset_uselzo(unsigned long data)
71 {
72 nx842_uselzo = 0;
73 }
74
75 static DEFINE_TIMER(failover_timer, nx842_reset_uselzo, 0, 0);
76
nx842_crypto_compress(struct crypto_tfm * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen)77 static int nx842_crypto_compress(struct crypto_tfm *tfm, const u8 *src,
78 unsigned int slen, u8 *dst, unsigned int *dlen)
79 {
80 struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
81 struct nx842_crypto_header *hdr;
82 unsigned int tmp_len = *dlen;
83 size_t lzodlen; /* needed for lzo */
84 int err;
85
86 *dlen = 0;
87 hdr = (struct nx842_crypto_header *)dst;
88 hdr->sentinel = NX842_SENTINEL; /* debug */
89 dst += sizeof(struct nx842_crypto_header);
90 tmp_len -= sizeof(struct nx842_crypto_header);
91 lzodlen = tmp_len;
92
93 if (likely(!nx842_uselzo)) {
94 err = nx842_compress(src, slen, dst, &tmp_len, ctx->nx842_wmem);
95
96 if (likely(!err)) {
97 hdr->type = NX842_CRYPTO_TYPE_842;
98 *dlen = tmp_len + sizeof(struct nx842_crypto_header);
99 return 0;
100 }
101
102 /* hardware failed */
103 nx842_uselzo = 1;
104
105 /* set timer to check for hardware again in 1 second */
106 mod_timer(&failover_timer, jiffies + msecs_to_jiffies(1000));
107 }
108
109 /* no hardware, use lzo */
110 err = lzo1x_1_compress(src, slen, dst, &lzodlen, ctx->nx842_wmem);
111 if (err != LZO_E_OK)
112 return -EINVAL;
113
114 hdr->type = NX842_CRYPTO_TYPE_LZO;
115 *dlen = lzodlen + sizeof(struct nx842_crypto_header);
116 return 0;
117 }
118
nx842_crypto_decompress(struct crypto_tfm * tfm,const u8 * src,unsigned int slen,u8 * dst,unsigned int * dlen)119 static int nx842_crypto_decompress(struct crypto_tfm *tfm, const u8 *src,
120 unsigned int slen, u8 *dst, unsigned int *dlen)
121 {
122 struct nx842_ctx *ctx = crypto_tfm_ctx(tfm);
123 struct nx842_crypto_header *hdr;
124 unsigned int tmp_len = *dlen;
125 size_t lzodlen; /* needed for lzo */
126 int err;
127
128 *dlen = 0;
129 hdr = (struct nx842_crypto_header *)src;
130
131 if (unlikely(hdr->sentinel != NX842_SENTINEL))
132 return -EINVAL;
133
134 src += sizeof(struct nx842_crypto_header);
135 slen -= sizeof(struct nx842_crypto_header);
136
137 if (likely(hdr->type == NX842_CRYPTO_TYPE_842)) {
138 err = nx842_decompress(src, slen, dst, &tmp_len,
139 ctx->nx842_wmem);
140 if (err)
141 return -EINVAL;
142 *dlen = tmp_len;
143 } else if (hdr->type == NX842_CRYPTO_TYPE_LZO) {
144 lzodlen = tmp_len;
145 err = lzo1x_decompress_safe(src, slen, dst, &lzodlen);
146 if (err != LZO_E_OK)
147 return -EINVAL;
148 *dlen = lzodlen;
149 } else
150 return -EINVAL;
151
152 return 0;
153 }
154
155 static struct crypto_alg alg = {
156 .cra_name = "842",
157 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
158 .cra_ctxsize = sizeof(struct nx842_ctx),
159 .cra_module = THIS_MODULE,
160 .cra_init = nx842_init,
161 .cra_exit = nx842_exit,
162 .cra_u = { .compress = {
163 .coa_compress = nx842_crypto_compress,
164 .coa_decompress = nx842_crypto_decompress } }
165 };
166
nx842_mod_init(void)167 static int __init nx842_mod_init(void)
168 {
169 del_timer(&failover_timer);
170 return crypto_register_alg(&alg);
171 }
172
nx842_mod_exit(void)173 static void __exit nx842_mod_exit(void)
174 {
175 crypto_unregister_alg(&alg);
176 }
177
178 module_init(nx842_mod_init);
179 module_exit(nx842_mod_exit);
180
181 MODULE_LICENSE("GPL");
182 MODULE_DESCRIPTION("842 Compression Algorithm");
183 MODULE_ALIAS_CRYPTO("842");
184