1 /*
2 * Cryptographic API.
3 *
4 * T10 Data Integrity Field CRC16 Crypto Transform using PCLMULQDQ Instructions
5 *
6 * Copyright (C) 2013 Intel Corporation
7 * Author: Tim Chen <tim.c.chen@linux.intel.com>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
15 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
17 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
18 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
19 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
20 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 *
23 */
24
25 #include <linux/types.h>
26 #include <linux/module.h>
27 #include <linux/crc-t10dif.h>
28 #include <crypto/internal/hash.h>
29 #include <linux/init.h>
30 #include <linux/string.h>
31 #include <linux/kernel.h>
32 #include <asm/fpu/api.h>
33 #include <asm/cpufeatures.h>
34 #include <asm/cpu_device_id.h>
35
36 asmlinkage __u16 crc_t10dif_pcl(__u16 crc, const unsigned char *buf,
37 size_t len);
38
39 struct chksum_desc_ctx {
40 __u16 crc;
41 };
42
43 /*
44 * Steps through buffer one byte at at time, calculates reflected
45 * crc using table.
46 */
47
chksum_init(struct shash_desc * desc)48 static int chksum_init(struct shash_desc *desc)
49 {
50 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
51
52 ctx->crc = 0;
53
54 return 0;
55 }
56
chksum_update(struct shash_desc * desc,const u8 * data,unsigned int length)57 static int chksum_update(struct shash_desc *desc, const u8 *data,
58 unsigned int length)
59 {
60 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
61
62 if (irq_fpu_usable()) {
63 kernel_fpu_begin();
64 ctx->crc = crc_t10dif_pcl(ctx->crc, data, length);
65 kernel_fpu_end();
66 } else
67 ctx->crc = crc_t10dif_generic(ctx->crc, data, length);
68 return 0;
69 }
70
chksum_final(struct shash_desc * desc,u8 * out)71 static int chksum_final(struct shash_desc *desc, u8 *out)
72 {
73 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
74
75 *(__u16 *)out = ctx->crc;
76 return 0;
77 }
78
__chksum_finup(__u16 crc,const u8 * data,unsigned int len,u8 * out)79 static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
80 {
81 if (irq_fpu_usable()) {
82 kernel_fpu_begin();
83 *(__u16 *)out = crc_t10dif_pcl(crc, data, len);
84 kernel_fpu_end();
85 } else
86 *(__u16 *)out = crc_t10dif_generic(crc, data, len);
87 return 0;
88 }
89
chksum_finup(struct shash_desc * desc,const u8 * data,unsigned int len,u8 * out)90 static int chksum_finup(struct shash_desc *desc, const u8 *data,
91 unsigned int len, u8 *out)
92 {
93 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
94
95 return __chksum_finup(ctx->crc, data, len, out);
96 }
97
chksum_digest(struct shash_desc * desc,const u8 * data,unsigned int length,u8 * out)98 static int chksum_digest(struct shash_desc *desc, const u8 *data,
99 unsigned int length, u8 *out)
100 {
101 return __chksum_finup(0, data, length, out);
102 }
103
104 static struct shash_alg alg = {
105 .digestsize = CRC_T10DIF_DIGEST_SIZE,
106 .init = chksum_init,
107 .update = chksum_update,
108 .final = chksum_final,
109 .finup = chksum_finup,
110 .digest = chksum_digest,
111 .descsize = sizeof(struct chksum_desc_ctx),
112 .base = {
113 .cra_name = "crct10dif",
114 .cra_driver_name = "crct10dif-pclmul",
115 .cra_priority = 200,
116 .cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
117 .cra_module = THIS_MODULE,
118 }
119 };
120
121 static const struct x86_cpu_id crct10dif_cpu_id[] = {
122 X86_FEATURE_MATCH(X86_FEATURE_PCLMULQDQ),
123 {}
124 };
125 MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id);
126
crct10dif_intel_mod_init(void)127 static int __init crct10dif_intel_mod_init(void)
128 {
129 if (!x86_match_cpu(crct10dif_cpu_id))
130 return -ENODEV;
131
132 return crypto_register_shash(&alg);
133 }
134
crct10dif_intel_mod_fini(void)135 static void __exit crct10dif_intel_mod_fini(void)
136 {
137 crypto_unregister_shash(&alg);
138 }
139
140 module_init(crct10dif_intel_mod_init);
141 module_exit(crct10dif_intel_mod_fini);
142
143 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
144 MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ.");
145 MODULE_LICENSE("GPL");
146
147 MODULE_ALIAS_CRYPTO("crct10dif");
148 MODULE_ALIAS_CRYPTO("crct10dif-pclmul");
149