summaryrefslogtreecommitdiff
path: root/arch/arm64/crypto/crc32-arm64.c
blob: 9499199924aebd4d6b27ced325d69918b641ddf3 (plain)
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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
/*
 * crc32-arm64.c - CRC32 and CRC32C using optional ARMv8 instructions
 *
 * Module based on crypto/crc32c_generic.c
 *
 * CRC32 loop taken from Ed Nevill's Hadoop CRC patch
 * http://mail-archives.apache.org/mod_mbox/hadoop-common-dev/201406.mbox/%3C1403687030.3355.19.camel%40localhost.localdomain%3E
 *
 * Using inline assembly instead of intrinsics in order to be backwards
 * compatible with older compilers.
 *
 * Copyright (C) 2014 Linaro Ltd <yazen.ghannam@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/unaligned/access_ok.h>
#include <linux/cpufeature.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>

#include <crypto/internal/hash.h>

MODULE_AUTHOR("Yazen Ghannam <yazen.ghannam@linaro.org>");
MODULE_DESCRIPTION("CRC32 and CRC32C using optional ARMv8 instructions");
MODULE_LICENSE("GPL v2");

#define CRC32X(crc, value) __asm__("crc32x %w[c], %w[c], %x[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32W(crc, value) __asm__("crc32w %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32H(crc, value) __asm__("crc32h %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32B(crc, value) __asm__("crc32b %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CX(crc, value) __asm__("crc32cx %w[c], %w[c], %x[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CW(crc, value) __asm__("crc32cw %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CH(crc, value) __asm__("crc32ch %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CB(crc, value) __asm__("crc32cb %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))

static u32 crc32_arm64_le_hw(u32 crc, const u8 *p, unsigned int len)
{
	s64 length = len;

	while ((length -= sizeof(u64)) >= 0) {
		CRC32X(crc, get_unaligned_le64(p));
		p += sizeof(u64);
	}

	/* The following is more efficient than the straight loop */
	if (length & sizeof(u32)) {
		CRC32W(crc, get_unaligned_le32(p));
		p += sizeof(u32);
	}
	if (length & sizeof(u16)) {
		CRC32H(crc, get_unaligned_le16(p));
		p += sizeof(u16);
	}
	if (length & sizeof(u8))
		CRC32B(crc, *p);

	return crc;
}

static u32 crc32c_arm64_le_hw(u32 crc, const u8 *p, unsigned int len)
{
	s64 length = len;

	while ((length -= sizeof(u64)) >= 0) {
		CRC32CX(crc, get_unaligned_le64(p));
		p += sizeof(u64);
	}

	/* The following is more efficient than the straight loop */
	if (length & sizeof(u32)) {
		CRC32CW(crc, get_unaligned_le32(p));
		p += sizeof(u32);
	}
	if (length & sizeof(u16)) {
		CRC32CH(crc, get_unaligned_le16(p));
		p += sizeof(u16);
	}
	if (length & sizeof(u8))
		CRC32CB(crc, *p);

	return crc;
}

#define CHKSUM_BLOCK_SIZE	1
#define CHKSUM_DIGEST_SIZE	4

struct chksum_ctx {
	u32 key;
};

struct chksum_desc_ctx {
	u32 crc;
};

static int chksum_init(struct shash_desc *desc)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	ctx->crc = mctx->key;

	return 0;
}

/*
 * Setting the seed allows arbitrary accumulators and flexible XOR policy
 * If your algorithm starts with ~0, then XOR with ~0 before you set
 * the seed.
 */
static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
			 unsigned int keylen)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(tfm);

	if (keylen != sizeof(mctx->key)) {
		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}
	mctx->key = get_unaligned_le32(key);
	return 0;
}

static int chksum_update(struct shash_desc *desc, const u8 *data,
			 unsigned int length)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	ctx->crc = crc32_arm64_le_hw(ctx->crc, data, length);
	return 0;
}

static int chksumc_update(struct shash_desc *desc, const u8 *data,
			 unsigned int length)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	ctx->crc = crc32c_arm64_le_hw(ctx->crc, data, length);
	return 0;
}

static int chksum_final(struct shash_desc *desc, u8 *out)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	put_unaligned_le32(~ctx->crc, out);
	return 0;
}

static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
{
	put_unaligned_le32(~crc32_arm64_le_hw(crc, data, len), out);
	return 0;
}

static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
{
	put_unaligned_le32(~crc32c_arm64_le_hw(crc, data, len), out);
	return 0;
}

static int chksum_finup(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *out)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	return __chksum_finup(ctx->crc, data, len, out);
}

static int chksumc_finup(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *out)
{
	struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);

	return __chksumc_finup(ctx->crc, data, len, out);
}

static int chksum_digest(struct shash_desc *desc, const u8 *data,
			 unsigned int length, u8 *out)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);

	return __chksum_finup(mctx->key, data, length, out);
}

static int chksumc_digest(struct shash_desc *desc, const u8 *data,
			 unsigned int length, u8 *out)
{
	struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);

	return __chksumc_finup(mctx->key, data, length, out);
}

static int crc32_cra_init(struct crypto_tfm *tfm)
{
	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);

	mctx->key = ~0;
	return 0;
}

static struct shash_alg crc32_alg = {
	.digestsize		=	CHKSUM_DIGEST_SIZE,
	.setkey			=	chksum_setkey,
	.init			=	chksum_init,
	.update			=	chksum_update,
	.final			=	chksum_final,
	.finup			=	chksum_finup,
	.digest			=	chksum_digest,
	.descsize		=	sizeof(struct chksum_desc_ctx),
	.base			=	{
		.cra_name		=	"crc32",
		.cra_driver_name	=	"crc32-arm64-hw",
		.cra_priority		=	300,
		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
		.cra_alignmask		=	0,
		.cra_ctxsize		=	sizeof(struct chksum_ctx),
		.cra_module		=	THIS_MODULE,
		.cra_init		=	crc32_cra_init,
	}
};

static struct shash_alg crc32c_alg = {
	.digestsize		=	CHKSUM_DIGEST_SIZE,
	.setkey			=	chksum_setkey,
	.init			=	chksum_init,
	.update			=	chksumc_update,
	.final			=	chksum_final,
	.finup			=	chksumc_finup,
	.digest			=	chksumc_digest,
	.descsize		=	sizeof(struct chksum_desc_ctx),
	.base			=	{
		.cra_name		=	"crc32c",
		.cra_driver_name	=	"crc32c-arm64-hw",
		.cra_priority		=	300,
		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
		.cra_alignmask		=	0,
		.cra_ctxsize		=	sizeof(struct chksum_ctx),
		.cra_module		=	THIS_MODULE,
		.cra_init		=	crc32_cra_init,
	}
};

static int __init crc32_mod_init(void)
{
	int err;

	err = crypto_register_shash(&crc32_alg);

	if (err)
		return err;

	err = crypto_register_shash(&crc32c_alg);

	if (err) {
		crypto_unregister_shash(&crc32_alg);
		return err;
	}

	return 0;
}

static void __exit crc32_mod_exit(void)
{
	crypto_unregister_shash(&crc32_alg);
	crypto_unregister_shash(&crc32c_alg);
}

module_cpu_feature_match(CRC32, crc32_mod_init);
module_exit(crc32_mod_exit);