1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
/* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is included
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see http://www.gnu.org/licenses
*
* Please visit http://www.xyratex.com/contact if you need additional
* information or have any questions.
*
* GPL HEADER END
*/
/*
* Copyright 2012 Xyratex Technology Limited
*
* Wrappers for kernel crypto shash api to pclmulqdq crc32 imlementation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/crc32.h>
#include <crypto/internal/hash.h>
#include <asm/cpufeatures.h>
#include <asm/cpu_device_id.h>
#include <asm/fpu/api.h>
#define CHKSUM_BLOCK_SIZE 1
#define CHKSUM_DIGEST_SIZE 4
#define PCLMUL_MIN_LEN 64L /* minimum size of buffer
* for crc32_pclmul_le_16 */
#define SCALE_F 16L /* size of xmm register */
#define SCALE_F_MASK (SCALE_F - 1)
u32 crc32_pclmul_le_16(unsigned char const *buffer, size_t len, u32 crc32);
static u32 __attribute__((pure))
crc32_pclmul_le(u32 crc, unsigned char const *p, size_t len)
{
unsigned int iquotient;
unsigned int iremainder;
unsigned int prealign;
if (len < PCLMUL_MIN_LEN + SCALE_F_MASK || !irq_fpu_usable())
return crc32_le(crc, p, len);
if ((long)p & SCALE_F_MASK) {
/* align p to 16 byte */
prealign = SCALE_F - ((long)p & SCALE_F_MASK);
crc = crc32_le(crc, p, prealign);
len -= prealign;
p = (unsigned char *)(((unsigned long)p + SCALE_F_MASK) &
~SCALE_F_MASK);
}
iquotient = len & (~SCALE_F_MASK);
iremainder = len & SCALE_F_MASK;
kernel_fpu_begin();
crc = crc32_pclmul_le_16(p, iquotient, crc);
kernel_fpu_end();
if (iremainder)
crc = crc32_le(crc, p + iquotient, iremainder);
return crc;
}
static int crc32_pclmul_cra_init(struct crypto_tfm *tfm)
{
u32 *key = crypto_tfm_ctx(tfm);
*key = 0;
return 0;
}
static int crc32_pclmul_setkey(struct crypto_shash *hash, const u8 *key,
unsigned int keylen)
{
u32 *mctx = crypto_shash_ctx(hash);
if (keylen != sizeof(u32)) {
crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
*mctx = le32_to_cpup((__le32 *)key);
return 0;
}
static int crc32_pclmul_init(struct shash_desc *desc)
{
u32 *mctx = crypto_shash_ctx(desc->tfm);
u32 *crcp = shash_desc_ctx(desc);
*crcp = *mctx;
return 0;
}
static int crc32_pclmul_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
u32 *crcp = shash_desc_ctx(desc);
*crcp = crc32_pclmul_le(*crcp, data, len);
return 0;
}
/* No final XOR 0xFFFFFFFF, like crc32_le */
static int __crc32_pclmul_finup(u32 *crcp, const u8 *data, unsigned int len,
u8 *out)
{
*(__le32 *)out = cpu_to_le32(crc32_pclmul_le(*crcp, data, len));
return 0;
}
static int crc32_pclmul_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
return __crc32_pclmul_finup(shash_desc_ctx(desc), data, len, out);
}
static int crc32_pclmul_final(struct shash_desc *desc, u8 *out)
{
u32 *crcp = shash_desc_ctx(desc);
*(__le32 *)out = cpu_to_le32p(crcp);
return 0;
}
static int crc32_pclmul_digest(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
return __crc32_pclmul_finup(crypto_shash_ctx(desc->tfm), data, len,
out);
}
static struct shash_alg alg = {
.setkey = crc32_pclmul_setkey,
.init = crc32_pclmul_init,
.update = crc32_pclmul_update,
.final = crc32_pclmul_final,
.finup = crc32_pclmul_finup,
.digest = crc32_pclmul_digest,
.descsize = sizeof(u32),
.digestsize = CHKSUM_DIGEST_SIZE,
.base = {
.cra_name = "crc32",
.cra_driver_name = "crc32-pclmul",
.cra_priority = 200,
.cra_blocksize = CHKSUM_BLOCK_SIZE,
.cra_ctxsize = sizeof(u32),
.cra_module = THIS_MODULE,
.cra_init = crc32_pclmul_cra_init,
}
};
static const struct x86_cpu_id crc32pclmul_cpu_id[] = {
X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
{}
};
MODULE_DEVICE_TABLE(x86cpu, crc32pclmul_cpu_id);
static int __init crc32_pclmul_mod_init(void)
{
if (!x86_match_cpu(crc32pclmul_cpu_id)) {
pr_info("PCLMULQDQ-NI instructions are not detected.\n");
return -ENODEV;
}
return crypto_register_shash(&alg);
}
static void __exit crc32_pclmul_mod_fini(void)
{
crypto_unregister_shash(&alg);
}
module_init(crc32_pclmul_mod_init);
module_exit(crc32_pclmul_mod_fini);
MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CRYPTO("crc32");
MODULE_ALIAS_CRYPTO("crc32-pclmul");
|
