1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * t10_pi.c - Functions for generating and verifying T10 Protection |
4 | * Information. |
5 | */ |
6 | |
7 | #include <linux/t10-pi.h> |
8 | #include <linux/blk-integrity.h> |
9 | #include <linux/crc-t10dif.h> |
10 | #include <linux/crc64.h> |
11 | #include <linux/module.h> |
12 | #include <net/checksum.h> |
13 | #include <asm/unaligned.h> |
14 | |
15 | typedef __be16 (csum_fn) (void *, unsigned int); |
16 | |
17 | static __be16 t10_pi_crc_fn(void *data, unsigned int len) |
18 | { |
19 | return cpu_to_be16(crc_t10dif(data, len)); |
20 | } |
21 | |
22 | static __be16 t10_pi_ip_fn(void *data, unsigned int len) |
23 | { |
24 | return (__force __be16)ip_compute_csum(buff: data, len); |
25 | } |
26 | |
27 | /* |
28 | * Type 1 and Type 2 protection use the same format: 16 bit guard tag, |
29 | * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref |
30 | * tag. |
31 | */ |
32 | static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter, |
33 | csum_fn *fn, enum t10_dif_type type) |
34 | { |
35 | unsigned int i; |
36 | |
37 | for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
38 | struct t10_pi_tuple *pi = iter->prot_buf; |
39 | |
40 | pi->guard_tag = fn(iter->data_buf, iter->interval); |
41 | pi->app_tag = 0; |
42 | |
43 | if (type == T10_PI_TYPE1_PROTECTION) |
44 | pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed)); |
45 | else |
46 | pi->ref_tag = 0; |
47 | |
48 | iter->data_buf += iter->interval; |
49 | iter->prot_buf += iter->tuple_size; |
50 | iter->seed++; |
51 | } |
52 | |
53 | return BLK_STS_OK; |
54 | } |
55 | |
56 | static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter, |
57 | csum_fn *fn, enum t10_dif_type type) |
58 | { |
59 | unsigned int i; |
60 | |
61 | BUG_ON(type == T10_PI_TYPE0_PROTECTION); |
62 | |
63 | for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
64 | struct t10_pi_tuple *pi = iter->prot_buf; |
65 | __be16 csum; |
66 | |
67 | if (type == T10_PI_TYPE1_PROTECTION || |
68 | type == T10_PI_TYPE2_PROTECTION) { |
69 | if (pi->app_tag == T10_PI_APP_ESCAPE) |
70 | goto next; |
71 | |
72 | if (be32_to_cpu(pi->ref_tag) != |
73 | lower_32_bits(iter->seed)) { |
74 | pr_err("%s: ref tag error at location %llu " \ |
75 | "(rcvd %u)\n" , iter->disk_name, |
76 | (unsigned long long) |
77 | iter->seed, be32_to_cpu(pi->ref_tag)); |
78 | return BLK_STS_PROTECTION; |
79 | } |
80 | } else if (type == T10_PI_TYPE3_PROTECTION) { |
81 | if (pi->app_tag == T10_PI_APP_ESCAPE && |
82 | pi->ref_tag == T10_PI_REF_ESCAPE) |
83 | goto next; |
84 | } |
85 | |
86 | csum = fn(iter->data_buf, iter->interval); |
87 | |
88 | if (pi->guard_tag != csum) { |
89 | pr_err("%s: guard tag error at sector %llu " \ |
90 | "(rcvd %04x, want %04x)\n" , iter->disk_name, |
91 | (unsigned long long)iter->seed, |
92 | be16_to_cpu(pi->guard_tag), be16_to_cpu(csum)); |
93 | return BLK_STS_PROTECTION; |
94 | } |
95 | |
96 | next: |
97 | iter->data_buf += iter->interval; |
98 | iter->prot_buf += iter->tuple_size; |
99 | iter->seed++; |
100 | } |
101 | |
102 | return BLK_STS_OK; |
103 | } |
104 | |
105 | static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter) |
106 | { |
107 | return t10_pi_generate(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE1_PROTECTION); |
108 | } |
109 | |
110 | static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter) |
111 | { |
112 | return t10_pi_generate(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE1_PROTECTION); |
113 | } |
114 | |
115 | static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter) |
116 | { |
117 | return t10_pi_verify(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE1_PROTECTION); |
118 | } |
119 | |
120 | static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter) |
121 | { |
122 | return t10_pi_verify(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE1_PROTECTION); |
123 | } |
124 | |
125 | /** |
126 | * t10_pi_type1_prepare - prepare PI prior submitting request to device |
127 | * @rq: request with PI that should be prepared |
128 | * |
129 | * For Type 1/Type 2, the virtual start sector is the one that was |
130 | * originally submitted by the block layer for the ref_tag usage. Due to |
131 | * partitioning, MD/DM cloning, etc. the actual physical start sector is |
132 | * likely to be different. Remap protection information to match the |
133 | * physical LBA. |
134 | */ |
135 | static void t10_pi_type1_prepare(struct request *rq) |
136 | { |
137 | const int tuple_sz = rq->q->integrity.tuple_size; |
138 | u32 ref_tag = t10_pi_ref_tag(rq); |
139 | struct bio *bio; |
140 | |
141 | __rq_for_each_bio(bio, rq) { |
142 | struct bio_integrity_payload *bip = bio_integrity(bio); |
143 | u32 virt = bip_get_seed(bip) & 0xffffffff; |
144 | struct bio_vec iv; |
145 | struct bvec_iter iter; |
146 | |
147 | /* Already remapped? */ |
148 | if (bip->bip_flags & BIP_MAPPED_INTEGRITY) |
149 | break; |
150 | |
151 | bip_for_each_vec(iv, bip, iter) { |
152 | unsigned int j; |
153 | void *p; |
154 | |
155 | p = bvec_kmap_local(bvec: &iv); |
156 | for (j = 0; j < iv.bv_len; j += tuple_sz) { |
157 | struct t10_pi_tuple *pi = p; |
158 | |
159 | if (be32_to_cpu(pi->ref_tag) == virt) |
160 | pi->ref_tag = cpu_to_be32(ref_tag); |
161 | virt++; |
162 | ref_tag++; |
163 | p += tuple_sz; |
164 | } |
165 | kunmap_local(p); |
166 | } |
167 | |
168 | bip->bip_flags |= BIP_MAPPED_INTEGRITY; |
169 | } |
170 | } |
171 | |
172 | /** |
173 | * t10_pi_type1_complete - prepare PI prior returning request to the blk layer |
174 | * @rq: request with PI that should be prepared |
175 | * @nr_bytes: total bytes to prepare |
176 | * |
177 | * For Type 1/Type 2, the virtual start sector is the one that was |
178 | * originally submitted by the block layer for the ref_tag usage. Due to |
179 | * partitioning, MD/DM cloning, etc. the actual physical start sector is |
180 | * likely to be different. Since the physical start sector was submitted |
181 | * to the device, we should remap it back to virtual values expected by the |
182 | * block layer. |
183 | */ |
184 | static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes) |
185 | { |
186 | unsigned intervals = nr_bytes >> rq->q->integrity.interval_exp; |
187 | const int tuple_sz = rq->q->integrity.tuple_size; |
188 | u32 ref_tag = t10_pi_ref_tag(rq); |
189 | struct bio *bio; |
190 | |
191 | __rq_for_each_bio(bio, rq) { |
192 | struct bio_integrity_payload *bip = bio_integrity(bio); |
193 | u32 virt = bip_get_seed(bip) & 0xffffffff; |
194 | struct bio_vec iv; |
195 | struct bvec_iter iter; |
196 | |
197 | bip_for_each_vec(iv, bip, iter) { |
198 | unsigned int j; |
199 | void *p; |
200 | |
201 | p = bvec_kmap_local(bvec: &iv); |
202 | for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) { |
203 | struct t10_pi_tuple *pi = p; |
204 | |
205 | if (be32_to_cpu(pi->ref_tag) == ref_tag) |
206 | pi->ref_tag = cpu_to_be32(virt); |
207 | virt++; |
208 | ref_tag++; |
209 | intervals--; |
210 | p += tuple_sz; |
211 | } |
212 | kunmap_local(p); |
213 | } |
214 | } |
215 | } |
216 | |
217 | static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter) |
218 | { |
219 | return t10_pi_generate(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE3_PROTECTION); |
220 | } |
221 | |
222 | static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter) |
223 | { |
224 | return t10_pi_generate(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE3_PROTECTION); |
225 | } |
226 | |
227 | static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter) |
228 | { |
229 | return t10_pi_verify(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE3_PROTECTION); |
230 | } |
231 | |
232 | static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter) |
233 | { |
234 | return t10_pi_verify(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE3_PROTECTION); |
235 | } |
236 | |
237 | /* Type 3 does not have a reference tag so no remapping is required. */ |
238 | static void t10_pi_type3_prepare(struct request *rq) |
239 | { |
240 | } |
241 | |
242 | /* Type 3 does not have a reference tag so no remapping is required. */ |
243 | static void t10_pi_type3_complete(struct request *rq, unsigned int nr_bytes) |
244 | { |
245 | } |
246 | |
247 | const struct blk_integrity_profile t10_pi_type1_crc = { |
248 | .name = "T10-DIF-TYPE1-CRC" , |
249 | .generate_fn = t10_pi_type1_generate_crc, |
250 | .verify_fn = t10_pi_type1_verify_crc, |
251 | .prepare_fn = t10_pi_type1_prepare, |
252 | .complete_fn = t10_pi_type1_complete, |
253 | }; |
254 | EXPORT_SYMBOL(t10_pi_type1_crc); |
255 | |
256 | const struct blk_integrity_profile t10_pi_type1_ip = { |
257 | .name = "T10-DIF-TYPE1-IP" , |
258 | .generate_fn = t10_pi_type1_generate_ip, |
259 | .verify_fn = t10_pi_type1_verify_ip, |
260 | .prepare_fn = t10_pi_type1_prepare, |
261 | .complete_fn = t10_pi_type1_complete, |
262 | }; |
263 | EXPORT_SYMBOL(t10_pi_type1_ip); |
264 | |
265 | const struct blk_integrity_profile t10_pi_type3_crc = { |
266 | .name = "T10-DIF-TYPE3-CRC" , |
267 | .generate_fn = t10_pi_type3_generate_crc, |
268 | .verify_fn = t10_pi_type3_verify_crc, |
269 | .prepare_fn = t10_pi_type3_prepare, |
270 | .complete_fn = t10_pi_type3_complete, |
271 | }; |
272 | EXPORT_SYMBOL(t10_pi_type3_crc); |
273 | |
274 | const struct blk_integrity_profile t10_pi_type3_ip = { |
275 | .name = "T10-DIF-TYPE3-IP" , |
276 | .generate_fn = t10_pi_type3_generate_ip, |
277 | .verify_fn = t10_pi_type3_verify_ip, |
278 | .prepare_fn = t10_pi_type3_prepare, |
279 | .complete_fn = t10_pi_type3_complete, |
280 | }; |
281 | EXPORT_SYMBOL(t10_pi_type3_ip); |
282 | |
283 | static __be64 ext_pi_crc64(void *data, unsigned int len) |
284 | { |
285 | return cpu_to_be64(crc64_rocksoft(data, len)); |
286 | } |
287 | |
288 | static blk_status_t ext_pi_crc64_generate(struct blk_integrity_iter *iter, |
289 | enum t10_dif_type type) |
290 | { |
291 | unsigned int i; |
292 | |
293 | for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
294 | struct crc64_pi_tuple *pi = iter->prot_buf; |
295 | |
296 | pi->guard_tag = ext_pi_crc64(data: iter->data_buf, len: iter->interval); |
297 | pi->app_tag = 0; |
298 | |
299 | if (type == T10_PI_TYPE1_PROTECTION) |
300 | put_unaligned_be48(val: iter->seed, p: pi->ref_tag); |
301 | else |
302 | put_unaligned_be48(val: 0ULL, p: pi->ref_tag); |
303 | |
304 | iter->data_buf += iter->interval; |
305 | iter->prot_buf += iter->tuple_size; |
306 | iter->seed++; |
307 | } |
308 | |
309 | return BLK_STS_OK; |
310 | } |
311 | |
312 | static bool ext_pi_ref_escape(u8 *ref_tag) |
313 | { |
314 | static u8 ref_escape[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; |
315 | |
316 | return memcmp(p: ref_tag, q: ref_escape, size: sizeof(ref_escape)) == 0; |
317 | } |
318 | |
319 | static blk_status_t ext_pi_crc64_verify(struct blk_integrity_iter *iter, |
320 | enum t10_dif_type type) |
321 | { |
322 | unsigned int i; |
323 | |
324 | for (i = 0; i < iter->data_size; i += iter->interval) { |
325 | struct crc64_pi_tuple *pi = iter->prot_buf; |
326 | u64 ref, seed; |
327 | __be64 csum; |
328 | |
329 | if (type == T10_PI_TYPE1_PROTECTION) { |
330 | if (pi->app_tag == T10_PI_APP_ESCAPE) |
331 | goto next; |
332 | |
333 | ref = get_unaligned_be48(p: pi->ref_tag); |
334 | seed = lower_48_bits(n: iter->seed); |
335 | if (ref != seed) { |
336 | pr_err("%s: ref tag error at location %llu (rcvd %llu)\n" , |
337 | iter->disk_name, seed, ref); |
338 | return BLK_STS_PROTECTION; |
339 | } |
340 | } else if (type == T10_PI_TYPE3_PROTECTION) { |
341 | if (pi->app_tag == T10_PI_APP_ESCAPE && |
342 | ext_pi_ref_escape(ref_tag: pi->ref_tag)) |
343 | goto next; |
344 | } |
345 | |
346 | csum = ext_pi_crc64(data: iter->data_buf, len: iter->interval); |
347 | if (pi->guard_tag != csum) { |
348 | pr_err("%s: guard tag error at sector %llu " \ |
349 | "(rcvd %016llx, want %016llx)\n" , |
350 | iter->disk_name, (unsigned long long)iter->seed, |
351 | be64_to_cpu(pi->guard_tag), be64_to_cpu(csum)); |
352 | return BLK_STS_PROTECTION; |
353 | } |
354 | |
355 | next: |
356 | iter->data_buf += iter->interval; |
357 | iter->prot_buf += iter->tuple_size; |
358 | iter->seed++; |
359 | } |
360 | |
361 | return BLK_STS_OK; |
362 | } |
363 | |
364 | static blk_status_t ext_pi_type1_verify_crc64(struct blk_integrity_iter *iter) |
365 | { |
366 | return ext_pi_crc64_verify(iter, type: T10_PI_TYPE1_PROTECTION); |
367 | } |
368 | |
369 | static blk_status_t ext_pi_type1_generate_crc64(struct blk_integrity_iter *iter) |
370 | { |
371 | return ext_pi_crc64_generate(iter, type: T10_PI_TYPE1_PROTECTION); |
372 | } |
373 | |
374 | static void ext_pi_type1_prepare(struct request *rq) |
375 | { |
376 | const int tuple_sz = rq->q->integrity.tuple_size; |
377 | u64 ref_tag = ext_pi_ref_tag(rq); |
378 | struct bio *bio; |
379 | |
380 | __rq_for_each_bio(bio, rq) { |
381 | struct bio_integrity_payload *bip = bio_integrity(bio); |
382 | u64 virt = lower_48_bits(n: bip_get_seed(bip)); |
383 | struct bio_vec iv; |
384 | struct bvec_iter iter; |
385 | |
386 | /* Already remapped? */ |
387 | if (bip->bip_flags & BIP_MAPPED_INTEGRITY) |
388 | break; |
389 | |
390 | bip_for_each_vec(iv, bip, iter) { |
391 | unsigned int j; |
392 | void *p; |
393 | |
394 | p = bvec_kmap_local(bvec: &iv); |
395 | for (j = 0; j < iv.bv_len; j += tuple_sz) { |
396 | struct crc64_pi_tuple *pi = p; |
397 | u64 ref = get_unaligned_be48(p: pi->ref_tag); |
398 | |
399 | if (ref == virt) |
400 | put_unaligned_be48(val: ref_tag, p: pi->ref_tag); |
401 | virt++; |
402 | ref_tag++; |
403 | p += tuple_sz; |
404 | } |
405 | kunmap_local(p); |
406 | } |
407 | |
408 | bip->bip_flags |= BIP_MAPPED_INTEGRITY; |
409 | } |
410 | } |
411 | |
412 | static void ext_pi_type1_complete(struct request *rq, unsigned int nr_bytes) |
413 | { |
414 | unsigned intervals = nr_bytes >> rq->q->integrity.interval_exp; |
415 | const int tuple_sz = rq->q->integrity.tuple_size; |
416 | u64 ref_tag = ext_pi_ref_tag(rq); |
417 | struct bio *bio; |
418 | |
419 | __rq_for_each_bio(bio, rq) { |
420 | struct bio_integrity_payload *bip = bio_integrity(bio); |
421 | u64 virt = lower_48_bits(n: bip_get_seed(bip)); |
422 | struct bio_vec iv; |
423 | struct bvec_iter iter; |
424 | |
425 | bip_for_each_vec(iv, bip, iter) { |
426 | unsigned int j; |
427 | void *p; |
428 | |
429 | p = bvec_kmap_local(bvec: &iv); |
430 | for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) { |
431 | struct crc64_pi_tuple *pi = p; |
432 | u64 ref = get_unaligned_be48(p: pi->ref_tag); |
433 | |
434 | if (ref == ref_tag) |
435 | put_unaligned_be48(val: virt, p: pi->ref_tag); |
436 | virt++; |
437 | ref_tag++; |
438 | intervals--; |
439 | p += tuple_sz; |
440 | } |
441 | kunmap_local(p); |
442 | } |
443 | } |
444 | } |
445 | |
446 | static blk_status_t ext_pi_type3_verify_crc64(struct blk_integrity_iter *iter) |
447 | { |
448 | return ext_pi_crc64_verify(iter, type: T10_PI_TYPE3_PROTECTION); |
449 | } |
450 | |
451 | static blk_status_t ext_pi_type3_generate_crc64(struct blk_integrity_iter *iter) |
452 | { |
453 | return ext_pi_crc64_generate(iter, type: T10_PI_TYPE3_PROTECTION); |
454 | } |
455 | |
456 | const struct blk_integrity_profile ext_pi_type1_crc64 = { |
457 | .name = "EXT-DIF-TYPE1-CRC64" , |
458 | .generate_fn = ext_pi_type1_generate_crc64, |
459 | .verify_fn = ext_pi_type1_verify_crc64, |
460 | .prepare_fn = ext_pi_type1_prepare, |
461 | .complete_fn = ext_pi_type1_complete, |
462 | }; |
463 | EXPORT_SYMBOL_GPL(ext_pi_type1_crc64); |
464 | |
465 | const struct blk_integrity_profile ext_pi_type3_crc64 = { |
466 | .name = "EXT-DIF-TYPE3-CRC64" , |
467 | .generate_fn = ext_pi_type3_generate_crc64, |
468 | .verify_fn = ext_pi_type3_verify_crc64, |
469 | .prepare_fn = t10_pi_type3_prepare, |
470 | .complete_fn = t10_pi_type3_complete, |
471 | }; |
472 | EXPORT_SYMBOL_GPL(ext_pi_type3_crc64); |
473 | |
474 | MODULE_LICENSE("GPL" ); |
475 | MODULE_LICENSE("GPL" ); |
476 | |