blob: 2c97912335a90944e04927eb7be8219f361e92e0 [file] [log] [blame]
Martin K. Petersen2341c2f2014-09-26 19:20:07 -04001/*
2 * t10_pi.c - Functions for generating and verifying T10 Protection
3 * Information.
4 *
5 * Copyright (C) 2007, 2008, 2014 Oracle Corporation
6 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License version
10 * 2 as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; see the file COPYING. If not, write to
19 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
20 * USA.
21 *
22 */
23
24#include <linux/t10-pi.h>
25#include <linux/blkdev.h>
26#include <linux/crc-t10dif.h>
27#include <net/checksum.h>
28
29typedef __be16 (csum_fn) (void *, unsigned int);
30
31static const __be16 APP_ESCAPE = (__force __be16) 0xffff;
32static const __be32 REF_ESCAPE = (__force __be32) 0xffffffff;
33
34static __be16 t10_pi_crc_fn(void *data, unsigned int len)
35{
36 return cpu_to_be16(crc_t10dif(data, len));
37}
38
39static __be16 t10_pi_ip_fn(void *data, unsigned int len)
40{
41 return (__force __be16)ip_compute_csum(data, len);
42}
43
44/*
45 * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
46 * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
47 * tag.
48 */
49static int t10_pi_generate(struct blk_integrity_iter *iter, csum_fn *fn,
50 unsigned int type)
51{
52 unsigned int i;
53
54 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
55 struct t10_pi_tuple *pi = iter->prot_buf;
56
57 pi->guard_tag = fn(iter->data_buf, iter->interval);
58 pi->app_tag = 0;
59
60 if (type == 1)
61 pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
62 else
63 pi->ref_tag = 0;
64
65 iter->data_buf += iter->interval;
66 iter->prot_buf += sizeof(struct t10_pi_tuple);
67 iter->seed++;
68 }
69
70 return 0;
71}
72
73static int t10_pi_verify(struct blk_integrity_iter *iter, csum_fn *fn,
74 unsigned int type)
75{
76 unsigned int i;
77
78 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
79 struct t10_pi_tuple *pi = iter->prot_buf;
80 __be16 csum;
81
82 switch (type) {
83 case 1:
84 case 2:
85 if (pi->app_tag == APP_ESCAPE)
86 goto next;
87
88 if (be32_to_cpu(pi->ref_tag) !=
89 lower_32_bits(iter->seed)) {
90 pr_err("%s: ref tag error at location %llu " \
91 "(rcvd %u)\n", iter->disk_name,
92 (unsigned long long)
93 iter->seed, be32_to_cpu(pi->ref_tag));
94 return -EILSEQ;
95 }
96 break;
97 case 3:
98 if (pi->app_tag == APP_ESCAPE &&
99 pi->ref_tag == REF_ESCAPE)
100 goto next;
101 break;
102 }
103
104 csum = fn(iter->data_buf, iter->interval);
105
106 if (pi->guard_tag != csum) {
107 pr_err("%s: guard tag error at sector %llu " \
108 "(rcvd %04x, want %04x)\n", iter->disk_name,
109 (unsigned long long)iter->seed,
110 be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
111 return -EILSEQ;
112 }
113
114next:
115 iter->data_buf += iter->interval;
116 iter->prot_buf += sizeof(struct t10_pi_tuple);
117 iter->seed++;
118 }
119
120 return 0;
121}
122
123static int t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
124{
125 return t10_pi_generate(iter, t10_pi_crc_fn, 1);
126}
127
128static int t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
129{
130 return t10_pi_generate(iter, t10_pi_ip_fn, 1);
131}
132
133static int t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
134{
135 return t10_pi_verify(iter, t10_pi_crc_fn, 1);
136}
137
138static int t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
139{
140 return t10_pi_verify(iter, t10_pi_ip_fn, 1);
141}
142
143static int t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
144{
145 return t10_pi_generate(iter, t10_pi_crc_fn, 3);
146}
147
148static int t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
149{
150 return t10_pi_generate(iter, t10_pi_ip_fn, 3);
151}
152
153static int t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
154{
155 return t10_pi_verify(iter, t10_pi_crc_fn, 3);
156}
157
158static int t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
159{
160 return t10_pi_verify(iter, t10_pi_ip_fn, 3);
161}
162
Martin K. Petersen0f8087e2015-10-21 13:19:33 -0400163struct blk_integrity_profile t10_pi_type1_crc = {
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400164 .name = "T10-DIF-TYPE1-CRC",
165 .generate_fn = t10_pi_type1_generate_crc,
166 .verify_fn = t10_pi_type1_verify_crc,
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400167};
168EXPORT_SYMBOL(t10_pi_type1_crc);
169
Martin K. Petersen0f8087e2015-10-21 13:19:33 -0400170struct blk_integrity_profile t10_pi_type1_ip = {
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400171 .name = "T10-DIF-TYPE1-IP",
172 .generate_fn = t10_pi_type1_generate_ip,
173 .verify_fn = t10_pi_type1_verify_ip,
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400174};
175EXPORT_SYMBOL(t10_pi_type1_ip);
176
Martin K. Petersen0f8087e2015-10-21 13:19:33 -0400177struct blk_integrity_profile t10_pi_type3_crc = {
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400178 .name = "T10-DIF-TYPE3-CRC",
179 .generate_fn = t10_pi_type3_generate_crc,
180 .verify_fn = t10_pi_type3_verify_crc,
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400181};
182EXPORT_SYMBOL(t10_pi_type3_crc);
183
Martin K. Petersen0f8087e2015-10-21 13:19:33 -0400184struct blk_integrity_profile t10_pi_type3_ip = {
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400185 .name = "T10-DIF-TYPE3-IP",
186 .generate_fn = t10_pi_type3_generate_ip,
187 .verify_fn = t10_pi_type3_verify_ip,
Martin K. Petersen2341c2f2014-09-26 19:20:07 -0400188};
189EXPORT_SYMBOL(t10_pi_type3_ip);