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 <crypto/internal/simd.h>
30 #include <linux/init.h>
31 #include <linux/string.h>
32 #include <linux/kernel.h>
33 #include <asm/cpufeatures.h>
34 #include <asm/cpu_device_id.h>
35 #include <asm/simd.h>
36
37 asmlinkage u16 crc_t10dif_pcl(u16 init_crc, const u8 *buf, size_t len);
38
39 struct chksum_desc_ctx {
40 __u16 crc;
41 };
42
43 static int chksum_init(struct shash_desc *desc)
44 {
45 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
46
47 ctx->crc = 0;
48
49 return 0;
50 }
51
52 static int chksum_update(struct shash_desc *desc, const u8 *data,
53 unsigned int length)
54 {
55 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
56
57 if (length >= 16 && crypto_simd_usable()) {
58 kernel_fpu_begin();
59 ctx->crc = crc_t10dif_pcl(ctx->crc, data, length);
60 kernel_fpu_end();
61 } else
62 ctx->crc = crc_t10dif_generic(ctx->crc, data, length);
63 return 0;
64 }
65
66 static int chksum_final(struct shash_desc *desc, u8 *out)
67 {
68 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
69
70 *(__u16 *)out = ctx->crc;
71 return 0;
72 }
73
74 static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
75 {
76 if (len >= 16 && crypto_simd_usable()) {
77 kernel_fpu_begin();
78 *(__u16 *)out = crc_t10dif_pcl(crc, data, len);
79 kernel_fpu_end();
80 } else
81 *(__u16 *)out = crc_t10dif_generic(crc, data, len);
82 return 0;
83 }
84
85 static int chksum_finup(struct shash_desc *desc, const u8 *data,
86 unsigned int len, u8 *out)
87 {
88 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
89
90 return __chksum_finup(ctx->crc, data, len, out);
91 }
92
93 static int chksum_digest(struct shash_desc *desc, const u8 *data,
94 unsigned int length, u8 *out)
95 {
96 return __chksum_finup(0, data, length, out);
97 }
98
99 static struct shash_alg alg = {
100 .digestsize = CRC_T10DIF_DIGEST_SIZE,
101 .init = chksum_init,
102 .update = chksum_update,
103 .final = chksum_final,
104 .finup = chksum_finup,
105 .digest = chksum_digest,
106 .descsize = sizeof(struct chksum_desc_ctx),
107 .base = {
108 .cra_name = "crct10dif",
109 .cra_driver_name = "crct10dif-pclmul",
110 .cra_priority = 200,
111 .cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
112 .cra_module = THIS_MODULE,
113 }
114 };
115
116 static const struct x86_cpu_id crct10dif_cpu_id[] = {
117 X86_MATCH_FEATURE(X86_FEATURE_PCLMULQDQ, NULL),
118 {}
119 };
120 MODULE_DEVICE_TABLE(x86cpu, crct10dif_cpu_id);
121
122 static int __init crct10dif_intel_mod_init(void)
123 {
124 if (!x86_match_cpu(crct10dif_cpu_id))
125 return -ENODEV;
126
127 return crypto_register_shash(&alg);
128 }
129
130 static void __exit crct10dif_intel_mod_fini(void)
131 {
132 crypto_unregister_shash(&alg);
133 }
134
135 module_init(crct10dif_intel_mod_init);
136 module_exit(crct10dif_intel_mod_fini);
137
138 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
139 MODULE_DESCRIPTION("T10 DIF CRC calculation accelerated with PCLMULQDQ.");
140 MODULE_LICENSE("GPL");
141
142 MODULE_ALIAS_CRYPTO("crct10dif");
143 MODULE_ALIAS_CRYPTO("crct10dif-pclmul");
144
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