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
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
|
/*
* Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions
*
* Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/cpufeature.h>
#include <linux/crc32.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <crypto/internal/hash.h>
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
#include <asm/unaligned.h>
#define PMULL_MIN_LEN 64L /* minimum size of buffer
* for crc32_pmull_le_16 */
#define SCALE_F 16L /* size of NEON register */
asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc);
asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len);
asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc);
asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len);
static u32 (*fallback_crc32)(u32 init_crc, const u8 buf[], u32 len);
static u32 (*fallback_crc32c)(u32 init_crc, const u8 buf[], u32 len);
static int crc32_cra_init(struct crypto_tfm *tfm)
{
u32 *key = crypto_tfm_ctx(tfm);
*key = 0;
return 0;
}
static int crc32c_cra_init(struct crypto_tfm *tfm)
{
u32 *key = crypto_tfm_ctx(tfm);
*key = ~0;
return 0;
}
static int crc32_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_init(struct shash_desc *desc)
{
u32 *mctx = crypto_shash_ctx(desc->tfm);
u32 *crc = shash_desc_ctx(desc);
*crc = *mctx;
return 0;
}
static int crc32_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
u32 *crc = shash_desc_ctx(desc);
*crc = crc32_armv8_le(*crc, data, length);
return 0;
}
static int crc32c_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
u32 *crc = shash_desc_ctx(desc);
*crc = crc32c_armv8_le(*crc, data, length);
return 0;
}
static int crc32_final(struct shash_desc *desc, u8 *out)
{
u32 *crc = shash_desc_ctx(desc);
put_unaligned_le32(*crc, out);
return 0;
}
static int crc32c_final(struct shash_desc *desc, u8 *out)
{
u32 *crc = shash_desc_ctx(desc);
put_unaligned_le32(~*crc, out);
return 0;
}
static int crc32_pmull_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
u32 *crc = shash_desc_ctx(desc);
unsigned int l;
if (may_use_simd()) {
if ((u32)data % SCALE_F) {
l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F));
*crc = fallback_crc32(*crc, data, l);
data += l;
length -= l;
}
if (length >= PMULL_MIN_LEN) {
l = round_down(length, SCALE_F);
kernel_neon_begin();
*crc = crc32_pmull_le(data, l, *crc);
kernel_neon_end();
data += l;
length -= l;
}
}
if (length > 0)
*crc = fallback_crc32(*crc, data, length);
return 0;
}
static int crc32c_pmull_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
u32 *crc = shash_desc_ctx(desc);
unsigned int l;
if (may_use_simd()) {
if ((u32)data % SCALE_F) {
l = min_t(u32, length, SCALE_F - ((u32)data % SCALE_F));
*crc = fallback_crc32c(*crc, data, l);
data += l;
length -= l;
}
if (length >= PMULL_MIN_LEN) {
l = round_down(length, SCALE_F);
kernel_neon_begin();
*crc = crc32c_pmull_le(data, l, *crc);
kernel_neon_end();
data += l;
length -= l;
}
}
if (length > 0)
*crc = fallback_crc32c(*crc, data, length);
return 0;
}
static struct shash_alg crc32_pmull_algs[] = { {
.setkey = crc32_setkey,
.init = crc32_init,
.update = crc32_update,
.final = crc32_final,
.descsize = sizeof(u32),
.digestsize = sizeof(u32),
.base.cra_ctxsize = sizeof(u32),
.base.cra_init = crc32_cra_init,
.base.cra_name = "crc32",
.base.cra_driver_name = "crc32-arm-ce",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
.base.cra_blocksize = 1,
.base.cra_module = THIS_MODULE,
}, {
.setkey = crc32_setkey,
.init = crc32_init,
.update = crc32c_update,
.final = crc32c_final,
.descsize = sizeof(u32),
.digestsize = sizeof(u32),
.base.cra_ctxsize = sizeof(u32),
.base.cra_init = crc32c_cra_init,
.base.cra_name = "crc32c",
.base.cra_driver_name = "crc32c-arm-ce",
.base.cra_priority = 200,
.base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
.base.cra_blocksize = 1,
.base.cra_module = THIS_MODULE,
} };
static int __init crc32_pmull_mod_init(void)
{
if (elf_hwcap2 & HWCAP2_PMULL) {
crc32_pmull_algs[0].update = crc32_pmull_update;
crc32_pmull_algs[1].update = crc32c_pmull_update;
if (elf_hwcap2 & HWCAP2_CRC32) {
fallback_crc32 = crc32_armv8_le;
fallback_crc32c = crc32c_armv8_le;
} else {
fallback_crc32 = crc32_le;
fallback_crc32c = __crc32c_le;
}
} else if (!(elf_hwcap2 & HWCAP2_CRC32)) {
return -ENODEV;
}
return crypto_register_shashes(crc32_pmull_algs,
ARRAY_SIZE(crc32_pmull_algs));
}
static void __exit crc32_pmull_mod_exit(void)
{
crypto_unregister_shashes(crc32_pmull_algs,
ARRAY_SIZE(crc32_pmull_algs));
}
static const struct cpu_feature crc32_cpu_feature[] = {
{ cpu_feature(CRC32) }, { cpu_feature(PMULL) }, { }
};
MODULE_DEVICE_TABLE(cpu, crc32_cpu_feature);
module_init(crc32_pmull_mod_init);
module_exit(crc32_pmull_mod_exit);
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("crc32");
MODULE_ALIAS_CRYPTO("crc32c");
|
