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8c16567d | 1 | // SPDX-License-Identifier: GPL-2.0 |
2341c2f8 MP |
2 | /* |
3 | * t10_pi.c - Functions for generating and verifying T10 Protection | |
4 | * Information. | |
2341c2f8 MP |
5 | */ |
6 | ||
7 | #include <linux/t10-pi.h> | |
8 | #include <linux/blkdev.h> | |
9 | #include <linux/crc-t10dif.h> | |
10 | #include <net/checksum.h> | |
11 | ||
12 | typedef __be16 (csum_fn) (void *, unsigned int); | |
13 | ||
2341c2f8 MP |
14 | static __be16 t10_pi_crc_fn(void *data, unsigned int len) |
15 | { | |
16 | return cpu_to_be16(crc_t10dif(data, len)); | |
17 | } | |
18 | ||
19 | static __be16 t10_pi_ip_fn(void *data, unsigned int len) | |
20 | { | |
21 | return (__force __be16)ip_compute_csum(data, len); | |
22 | } | |
23 | ||
24 | /* | |
25 | * Type 1 and Type 2 protection use the same format: 16 bit guard tag, | |
26 | * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref | |
27 | * tag. | |
28 | */ | |
4e4cbee9 CH |
29 | static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter, |
30 | csum_fn *fn, unsigned int type) | |
2341c2f8 MP |
31 | { |
32 | unsigned int i; | |
33 | ||
34 | for (i = 0 ; i < iter->data_size ; i += iter->interval) { | |
35 | struct t10_pi_tuple *pi = iter->prot_buf; | |
36 | ||
37 | pi->guard_tag = fn(iter->data_buf, iter->interval); | |
38 | pi->app_tag = 0; | |
39 | ||
40 | if (type == 1) | |
41 | pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed)); | |
42 | else | |
43 | pi->ref_tag = 0; | |
44 | ||
45 | iter->data_buf += iter->interval; | |
46 | iter->prot_buf += sizeof(struct t10_pi_tuple); | |
47 | iter->seed++; | |
48 | } | |
49 | ||
4e4cbee9 | 50 | return BLK_STS_OK; |
2341c2f8 MP |
51 | } |
52 | ||
4e4cbee9 CH |
53 | static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter, |
54 | csum_fn *fn, unsigned int type) | |
2341c2f8 MP |
55 | { |
56 | unsigned int i; | |
57 | ||
58 | for (i = 0 ; i < iter->data_size ; i += iter->interval) { | |
59 | struct t10_pi_tuple *pi = iter->prot_buf; | |
60 | __be16 csum; | |
61 | ||
62 | switch (type) { | |
63 | case 1: | |
64 | case 2: | |
128b6f9f | 65 | if (pi->app_tag == T10_PI_APP_ESCAPE) |
2341c2f8 MP |
66 | goto next; |
67 | ||
68 | if (be32_to_cpu(pi->ref_tag) != | |
69 | lower_32_bits(iter->seed)) { | |
70 | pr_err("%s: ref tag error at location %llu " \ | |
71 | "(rcvd %u)\n", iter->disk_name, | |
72 | (unsigned long long) | |
73 | iter->seed, be32_to_cpu(pi->ref_tag)); | |
a462b950 | 74 | return BLK_STS_PROTECTION; |
2341c2f8 MP |
75 | } |
76 | break; | |
77 | case 3: | |
128b6f9f DM |
78 | if (pi->app_tag == T10_PI_APP_ESCAPE && |
79 | pi->ref_tag == T10_PI_REF_ESCAPE) | |
2341c2f8 MP |
80 | goto next; |
81 | break; | |
82 | } | |
83 | ||
84 | csum = fn(iter->data_buf, iter->interval); | |
85 | ||
86 | if (pi->guard_tag != csum) { | |
87 | pr_err("%s: guard tag error at sector %llu " \ | |
88 | "(rcvd %04x, want %04x)\n", iter->disk_name, | |
89 | (unsigned long long)iter->seed, | |
90 | be16_to_cpu(pi->guard_tag), be16_to_cpu(csum)); | |
4e4cbee9 | 91 | return BLK_STS_PROTECTION; |
2341c2f8 MP |
92 | } |
93 | ||
94 | next: | |
95 | iter->data_buf += iter->interval; | |
96 | iter->prot_buf += sizeof(struct t10_pi_tuple); | |
97 | iter->seed++; | |
98 | } | |
99 | ||
4e4cbee9 | 100 | return BLK_STS_OK; |
2341c2f8 MP |
101 | } |
102 | ||
4e4cbee9 | 103 | static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter) |
2341c2f8 MP |
104 | { |
105 | return t10_pi_generate(iter, t10_pi_crc_fn, 1); | |
106 | } | |
107 | ||
4e4cbee9 | 108 | static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter) |
2341c2f8 MP |
109 | { |
110 | return t10_pi_generate(iter, t10_pi_ip_fn, 1); | |
111 | } | |
112 | ||
4e4cbee9 | 113 | static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter) |
2341c2f8 MP |
114 | { |
115 | return t10_pi_verify(iter, t10_pi_crc_fn, 1); | |
116 | } | |
117 | ||
4e4cbee9 | 118 | static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter) |
2341c2f8 MP |
119 | { |
120 | return t10_pi_verify(iter, t10_pi_ip_fn, 1); | |
121 | } | |
122 | ||
4e4cbee9 | 123 | static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter) |
2341c2f8 MP |
124 | { |
125 | return t10_pi_generate(iter, t10_pi_crc_fn, 3); | |
126 | } | |
127 | ||
4e4cbee9 | 128 | static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter) |
2341c2f8 MP |
129 | { |
130 | return t10_pi_generate(iter, t10_pi_ip_fn, 3); | |
131 | } | |
132 | ||
4e4cbee9 | 133 | static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter) |
2341c2f8 MP |
134 | { |
135 | return t10_pi_verify(iter, t10_pi_crc_fn, 3); | |
136 | } | |
137 | ||
4e4cbee9 | 138 | static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter) |
2341c2f8 MP |
139 | { |
140 | return t10_pi_verify(iter, t10_pi_ip_fn, 3); | |
141 | } | |
142 | ||
869ab90f | 143 | const struct blk_integrity_profile t10_pi_type1_crc = { |
2341c2f8 MP |
144 | .name = "T10-DIF-TYPE1-CRC", |
145 | .generate_fn = t10_pi_type1_generate_crc, | |
146 | .verify_fn = t10_pi_type1_verify_crc, | |
2341c2f8 MP |
147 | }; |
148 | EXPORT_SYMBOL(t10_pi_type1_crc); | |
149 | ||
869ab90f | 150 | const struct blk_integrity_profile t10_pi_type1_ip = { |
2341c2f8 MP |
151 | .name = "T10-DIF-TYPE1-IP", |
152 | .generate_fn = t10_pi_type1_generate_ip, | |
153 | .verify_fn = t10_pi_type1_verify_ip, | |
2341c2f8 MP |
154 | }; |
155 | EXPORT_SYMBOL(t10_pi_type1_ip); | |
156 | ||
869ab90f | 157 | const struct blk_integrity_profile t10_pi_type3_crc = { |
2341c2f8 MP |
158 | .name = "T10-DIF-TYPE3-CRC", |
159 | .generate_fn = t10_pi_type3_generate_crc, | |
160 | .verify_fn = t10_pi_type3_verify_crc, | |
2341c2f8 MP |
161 | }; |
162 | EXPORT_SYMBOL(t10_pi_type3_crc); | |
163 | ||
869ab90f | 164 | const struct blk_integrity_profile t10_pi_type3_ip = { |
2341c2f8 MP |
165 | .name = "T10-DIF-TYPE3-IP", |
166 | .generate_fn = t10_pi_type3_generate_ip, | |
167 | .verify_fn = t10_pi_type3_verify_ip, | |
2341c2f8 MP |
168 | }; |
169 | EXPORT_SYMBOL(t10_pi_type3_ip); | |
10c41ddd MG |
170 | |
171 | /** | |
172 | * t10_pi_prepare - prepare PI prior submitting request to device | |
173 | * @rq: request with PI that should be prepared | |
174 | * @protection_type: PI type (Type 1/Type 2/Type 3) | |
175 | * | |
176 | * For Type 1/Type 2, the virtual start sector is the one that was | |
177 | * originally submitted by the block layer for the ref_tag usage. Due to | |
178 | * partitioning, MD/DM cloning, etc. the actual physical start sector is | |
179 | * likely to be different. Remap protection information to match the | |
180 | * physical LBA. | |
181 | * | |
182 | * Type 3 does not have a reference tag so no remapping is required. | |
183 | */ | |
184 | void t10_pi_prepare(struct request *rq, u8 protection_type) | |
185 | { | |
186 | const int tuple_sz = rq->q->integrity.tuple_size; | |
187 | u32 ref_tag = t10_pi_ref_tag(rq); | |
188 | struct bio *bio; | |
189 | ||
190 | if (protection_type == T10_PI_TYPE3_PROTECTION) | |
191 | return; | |
192 | ||
193 | __rq_for_each_bio(bio, rq) { | |
194 | struct bio_integrity_payload *bip = bio_integrity(bio); | |
195 | u32 virt = bip_get_seed(bip) & 0xffffffff; | |
196 | struct bio_vec iv; | |
197 | struct bvec_iter iter; | |
198 | ||
199 | /* Already remapped? */ | |
200 | if (bip->bip_flags & BIP_MAPPED_INTEGRITY) | |
201 | break; | |
202 | ||
203 | bip_for_each_vec(iv, bip, iter) { | |
204 | void *p, *pmap; | |
205 | unsigned int j; | |
206 | ||
207 | pmap = kmap_atomic(iv.bv_page); | |
208 | p = pmap + iv.bv_offset; | |
209 | for (j = 0; j < iv.bv_len; j += tuple_sz) { | |
210 | struct t10_pi_tuple *pi = p; | |
211 | ||
212 | if (be32_to_cpu(pi->ref_tag) == virt) | |
213 | pi->ref_tag = cpu_to_be32(ref_tag); | |
214 | virt++; | |
215 | ref_tag++; | |
216 | p += tuple_sz; | |
217 | } | |
218 | ||
219 | kunmap_atomic(pmap); | |
220 | } | |
221 | ||
222 | bip->bip_flags |= BIP_MAPPED_INTEGRITY; | |
223 | } | |
224 | } | |
225 | EXPORT_SYMBOL(t10_pi_prepare); | |
226 | ||
227 | /** | |
228 | * t10_pi_complete - prepare PI prior returning request to the block layer | |
229 | * @rq: request with PI that should be prepared | |
230 | * @protection_type: PI type (Type 1/Type 2/Type 3) | |
231 | * @intervals: total elements to prepare | |
232 | * | |
233 | * For Type 1/Type 2, the virtual start sector is the one that was | |
234 | * originally submitted by the block layer for the ref_tag usage. Due to | |
235 | * partitioning, MD/DM cloning, etc. the actual physical start sector is | |
236 | * likely to be different. Since the physical start sector was submitted | |
237 | * to the device, we should remap it back to virtual values expected by the | |
238 | * block layer. | |
239 | * | |
240 | * Type 3 does not have a reference tag so no remapping is required. | |
241 | */ | |
242 | void t10_pi_complete(struct request *rq, u8 protection_type, | |
243 | unsigned int intervals) | |
244 | { | |
245 | const int tuple_sz = rq->q->integrity.tuple_size; | |
246 | u32 ref_tag = t10_pi_ref_tag(rq); | |
247 | struct bio *bio; | |
248 | ||
249 | if (protection_type == T10_PI_TYPE3_PROTECTION) | |
250 | return; | |
251 | ||
252 | __rq_for_each_bio(bio, rq) { | |
253 | struct bio_integrity_payload *bip = bio_integrity(bio); | |
254 | u32 virt = bip_get_seed(bip) & 0xffffffff; | |
255 | struct bio_vec iv; | |
256 | struct bvec_iter iter; | |
257 | ||
258 | bip_for_each_vec(iv, bip, iter) { | |
259 | void *p, *pmap; | |
260 | unsigned int j; | |
261 | ||
262 | pmap = kmap_atomic(iv.bv_page); | |
263 | p = pmap + iv.bv_offset; | |
264 | for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) { | |
265 | struct t10_pi_tuple *pi = p; | |
266 | ||
267 | if (be32_to_cpu(pi->ref_tag) == ref_tag) | |
268 | pi->ref_tag = cpu_to_be32(virt); | |
269 | virt++; | |
270 | ref_tag++; | |
271 | intervals--; | |
272 | p += tuple_sz; | |
273 | } | |
274 | ||
275 | kunmap_atomic(pmap); | |
276 | } | |
277 | } | |
278 | } | |
279 | EXPORT_SYMBOL(t10_pi_complete); |