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
15typedef __be16 (csum_fn) (__be16, void *, unsigned int);
16
17static __be16 t10_pi_crc_fn(__be16 crc, void *data, unsigned int len)
18{
19 return cpu_to_be16(crc_t10dif_update(be16_to_cpu(crc), data, len));
20}
21
22static __be16 t10_pi_ip_fn(__be16 csum, 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 */
32static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
33 csum_fn *fn, enum t10_dif_type type)
34{
35 u8 offset = iter->pi_offset;
36 unsigned int i;
37
38 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
39 struct t10_pi_tuple *pi = iter->prot_buf + offset;
40
41 pi->guard_tag = fn(0, iter->data_buf, iter->interval);
42 if (offset)
43 pi->guard_tag = fn(pi->guard_tag, iter->prot_buf,
44 offset);
45 pi->app_tag = 0;
46
47 if (type == T10_PI_TYPE1_PROTECTION)
48 pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
49 else
50 pi->ref_tag = 0;
51
52 iter->data_buf += iter->interval;
53 iter->prot_buf += iter->tuple_size;
54 iter->seed++;
55 }
56
57 return BLK_STS_OK;
58}
59
60static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
61 csum_fn *fn, enum t10_dif_type type)
62{
63 u8 offset = iter->pi_offset;
64 unsigned int i;
65
66 BUG_ON(type == T10_PI_TYPE0_PROTECTION);
67
68 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
69 struct t10_pi_tuple *pi = iter->prot_buf + offset;
70 __be16 csum;
71
72 if (type == T10_PI_TYPE1_PROTECTION ||
73 type == T10_PI_TYPE2_PROTECTION) {
74 if (pi->app_tag == T10_PI_APP_ESCAPE)
75 goto next;
76
77 if (be32_to_cpu(pi->ref_tag) !=
78 lower_32_bits(iter->seed)) {
79 pr_err("%s: ref tag error at location %llu " \
80 "(rcvd %u)\n", iter->disk_name,
81 (unsigned long long)
82 iter->seed, be32_to_cpu(pi->ref_tag));
83 return BLK_STS_PROTECTION;
84 }
85 } else if (type == T10_PI_TYPE3_PROTECTION) {
86 if (pi->app_tag == T10_PI_APP_ESCAPE &&
87 pi->ref_tag == T10_PI_REF_ESCAPE)
88 goto next;
89 }
90
91 csum = fn(0, iter->data_buf, iter->interval);
92 if (offset)
93 csum = fn(csum, iter->prot_buf, offset);
94
95 if (pi->guard_tag != csum) {
96 pr_err("%s: guard tag error at sector %llu " \
97 "(rcvd %04x, want %04x)\n", iter->disk_name,
98 (unsigned long long)iter->seed,
99 be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
100 return BLK_STS_PROTECTION;
101 }
102
103next:
104 iter->data_buf += iter->interval;
105 iter->prot_buf += iter->tuple_size;
106 iter->seed++;
107 }
108
109 return BLK_STS_OK;
110}
111
112static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
113{
114 return t10_pi_generate(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE1_PROTECTION);
115}
116
117static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
118{
119 return t10_pi_generate(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE1_PROTECTION);
120}
121
122static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
123{
124 return t10_pi_verify(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE1_PROTECTION);
125}
126
127static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
128{
129 return t10_pi_verify(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE1_PROTECTION);
130}
131
132/**
133 * t10_pi_type1_prepare - prepare PI prior submitting request to device
134 * @rq: request with PI that should be prepared
135 *
136 * For Type 1/Type 2, the virtual start sector is the one that was
137 * originally submitted by the block layer for the ref_tag usage. Due to
138 * partitioning, MD/DM cloning, etc. the actual physical start sector is
139 * likely to be different. Remap protection information to match the
140 * physical LBA.
141 */
142static void t10_pi_type1_prepare(struct request *rq)
143{
144 struct blk_integrity *bi = &rq->q->integrity;
145 const int tuple_sz = bi->tuple_size;
146 u32 ref_tag = t10_pi_ref_tag(rq);
147 u8 offset = bi->pi_offset;
148 struct bio *bio;
149
150 __rq_for_each_bio(bio, rq) {
151 struct bio_integrity_payload *bip = bio_integrity(bio);
152 u32 virt = bip_get_seed(bip) & 0xffffffff;
153 struct bio_vec iv;
154 struct bvec_iter iter;
155
156 /* Already remapped? */
157 if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
158 break;
159
160 bip_for_each_vec(iv, bip, iter) {
161 unsigned int j;
162 void *p;
163
164 p = bvec_kmap_local(bvec: &iv);
165 for (j = 0; j < iv.bv_len; j += tuple_sz) {
166 struct t10_pi_tuple *pi = p + offset;
167
168 if (be32_to_cpu(pi->ref_tag) == virt)
169 pi->ref_tag = cpu_to_be32(ref_tag);
170 virt++;
171 ref_tag++;
172 p += tuple_sz;
173 }
174 kunmap_local(p);
175 }
176
177 bip->bip_flags |= BIP_MAPPED_INTEGRITY;
178 }
179}
180
181/**
182 * t10_pi_type1_complete - prepare PI prior returning request to the blk layer
183 * @rq: request with PI that should be prepared
184 * @nr_bytes: total bytes to prepare
185 *
186 * For Type 1/Type 2, the virtual start sector is the one that was
187 * originally submitted by the block layer for the ref_tag usage. Due to
188 * partitioning, MD/DM cloning, etc. the actual physical start sector is
189 * likely to be different. Since the physical start sector was submitted
190 * to the device, we should remap it back to virtual values expected by the
191 * block layer.
192 */
193static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
194{
195 struct blk_integrity *bi = &rq->q->integrity;
196 unsigned intervals = nr_bytes >> bi->interval_exp;
197 const int tuple_sz = bi->tuple_size;
198 u32 ref_tag = t10_pi_ref_tag(rq);
199 u8 offset = bi->pi_offset;
200 struct bio *bio;
201
202 __rq_for_each_bio(bio, rq) {
203 struct bio_integrity_payload *bip = bio_integrity(bio);
204 u32 virt = bip_get_seed(bip) & 0xffffffff;
205 struct bio_vec iv;
206 struct bvec_iter iter;
207
208 bip_for_each_vec(iv, bip, iter) {
209 unsigned int j;
210 void *p;
211
212 p = bvec_kmap_local(bvec: &iv);
213 for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
214 struct t10_pi_tuple *pi = p + offset;
215
216 if (be32_to_cpu(pi->ref_tag) == ref_tag)
217 pi->ref_tag = cpu_to_be32(virt);
218 virt++;
219 ref_tag++;
220 intervals--;
221 p += tuple_sz;
222 }
223 kunmap_local(p);
224 }
225 }
226}
227
228static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
229{
230 return t10_pi_generate(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE3_PROTECTION);
231}
232
233static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
234{
235 return t10_pi_generate(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE3_PROTECTION);
236}
237
238static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
239{
240 return t10_pi_verify(iter, fn: t10_pi_crc_fn, type: T10_PI_TYPE3_PROTECTION);
241}
242
243static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
244{
245 return t10_pi_verify(iter, fn: t10_pi_ip_fn, type: T10_PI_TYPE3_PROTECTION);
246}
247
248/* Type 3 does not have a reference tag so no remapping is required. */
249static void t10_pi_type3_prepare(struct request *rq)
250{
251}
252
253/* Type 3 does not have a reference tag so no remapping is required. */
254static void t10_pi_type3_complete(struct request *rq, unsigned int nr_bytes)
255{
256}
257
258const struct blk_integrity_profile t10_pi_type1_crc = {
259 .name = "T10-DIF-TYPE1-CRC",
260 .generate_fn = t10_pi_type1_generate_crc,
261 .verify_fn = t10_pi_type1_verify_crc,
262 .prepare_fn = t10_pi_type1_prepare,
263 .complete_fn = t10_pi_type1_complete,
264};
265EXPORT_SYMBOL(t10_pi_type1_crc);
266
267const struct blk_integrity_profile t10_pi_type1_ip = {
268 .name = "T10-DIF-TYPE1-IP",
269 .generate_fn = t10_pi_type1_generate_ip,
270 .verify_fn = t10_pi_type1_verify_ip,
271 .prepare_fn = t10_pi_type1_prepare,
272 .complete_fn = t10_pi_type1_complete,
273};
274EXPORT_SYMBOL(t10_pi_type1_ip);
275
276const struct blk_integrity_profile t10_pi_type3_crc = {
277 .name = "T10-DIF-TYPE3-CRC",
278 .generate_fn = t10_pi_type3_generate_crc,
279 .verify_fn = t10_pi_type3_verify_crc,
280 .prepare_fn = t10_pi_type3_prepare,
281 .complete_fn = t10_pi_type3_complete,
282};
283EXPORT_SYMBOL(t10_pi_type3_crc);
284
285const struct blk_integrity_profile t10_pi_type3_ip = {
286 .name = "T10-DIF-TYPE3-IP",
287 .generate_fn = t10_pi_type3_generate_ip,
288 .verify_fn = t10_pi_type3_verify_ip,
289 .prepare_fn = t10_pi_type3_prepare,
290 .complete_fn = t10_pi_type3_complete,
291};
292EXPORT_SYMBOL(t10_pi_type3_ip);
293
294static __be64 ext_pi_crc64(u64 crc, void *data, unsigned int len)
295{
296 return cpu_to_be64(crc64_rocksoft_update(crc, data, len));
297}
298
299static blk_status_t ext_pi_crc64_generate(struct blk_integrity_iter *iter,
300 enum t10_dif_type type)
301{
302 u8 offset = iter->pi_offset;
303 unsigned int i;
304
305 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
306 struct crc64_pi_tuple *pi = iter->prot_buf + offset;
307
308 pi->guard_tag = ext_pi_crc64(crc: 0, data: iter->data_buf, len: iter->interval);
309 if (offset)
310 pi->guard_tag = ext_pi_crc64(be64_to_cpu(pi->guard_tag),
311 data: iter->prot_buf, len: offset);
312 pi->app_tag = 0;
313
314 if (type == T10_PI_TYPE1_PROTECTION)
315 put_unaligned_be48(val: iter->seed, p: pi->ref_tag);
316 else
317 put_unaligned_be48(val: 0ULL, p: pi->ref_tag);
318
319 iter->data_buf += iter->interval;
320 iter->prot_buf += iter->tuple_size;
321 iter->seed++;
322 }
323
324 return BLK_STS_OK;
325}
326
327static bool ext_pi_ref_escape(u8 *ref_tag)
328{
329 static u8 ref_escape[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
330
331 return memcmp(p: ref_tag, q: ref_escape, size: sizeof(ref_escape)) == 0;
332}
333
334static blk_status_t ext_pi_crc64_verify(struct blk_integrity_iter *iter,
335 enum t10_dif_type type)
336{
337 u8 offset = iter->pi_offset;
338 unsigned int i;
339
340 for (i = 0; i < iter->data_size; i += iter->interval) {
341 struct crc64_pi_tuple *pi = iter->prot_buf + offset;
342 u64 ref, seed;
343 __be64 csum;
344
345 if (type == T10_PI_TYPE1_PROTECTION) {
346 if (pi->app_tag == T10_PI_APP_ESCAPE)
347 goto next;
348
349 ref = get_unaligned_be48(p: pi->ref_tag);
350 seed = lower_48_bits(n: iter->seed);
351 if (ref != seed) {
352 pr_err("%s: ref tag error at location %llu (rcvd %llu)\n",
353 iter->disk_name, seed, ref);
354 return BLK_STS_PROTECTION;
355 }
356 } else if (type == T10_PI_TYPE3_PROTECTION) {
357 if (pi->app_tag == T10_PI_APP_ESCAPE &&
358 ext_pi_ref_escape(ref_tag: pi->ref_tag))
359 goto next;
360 }
361
362 csum = ext_pi_crc64(crc: 0, data: iter->data_buf, len: iter->interval);
363 if (offset)
364 csum = ext_pi_crc64(be64_to_cpu(csum), data: iter->prot_buf,
365 len: offset);
366
367 if (pi->guard_tag != csum) {
368 pr_err("%s: guard tag error at sector %llu " \
369 "(rcvd %016llx, want %016llx)\n",
370 iter->disk_name, (unsigned long long)iter->seed,
371 be64_to_cpu(pi->guard_tag), be64_to_cpu(csum));
372 return BLK_STS_PROTECTION;
373 }
374
375next:
376 iter->data_buf += iter->interval;
377 iter->prot_buf += iter->tuple_size;
378 iter->seed++;
379 }
380
381 return BLK_STS_OK;
382}
383
384static blk_status_t ext_pi_type1_verify_crc64(struct blk_integrity_iter *iter)
385{
386 return ext_pi_crc64_verify(iter, type: T10_PI_TYPE1_PROTECTION);
387}
388
389static blk_status_t ext_pi_type1_generate_crc64(struct blk_integrity_iter *iter)
390{
391 return ext_pi_crc64_generate(iter, type: T10_PI_TYPE1_PROTECTION);
392}
393
394static void ext_pi_type1_prepare(struct request *rq)
395{
396 struct blk_integrity *bi = &rq->q->integrity;
397 const int tuple_sz = bi->tuple_size;
398 u64 ref_tag = ext_pi_ref_tag(rq);
399 u8 offset = bi->pi_offset;
400 struct bio *bio;
401
402 __rq_for_each_bio(bio, rq) {
403 struct bio_integrity_payload *bip = bio_integrity(bio);
404 u64 virt = lower_48_bits(n: bip_get_seed(bip));
405 struct bio_vec iv;
406 struct bvec_iter iter;
407
408 /* Already remapped? */
409 if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
410 break;
411
412 bip_for_each_vec(iv, bip, iter) {
413 unsigned int j;
414 void *p;
415
416 p = bvec_kmap_local(bvec: &iv);
417 for (j = 0; j < iv.bv_len; j += tuple_sz) {
418 struct crc64_pi_tuple *pi = p + offset;
419 u64 ref = get_unaligned_be48(p: pi->ref_tag);
420
421 if (ref == virt)
422 put_unaligned_be48(val: ref_tag, p: pi->ref_tag);
423 virt++;
424 ref_tag++;
425 p += tuple_sz;
426 }
427 kunmap_local(p);
428 }
429
430 bip->bip_flags |= BIP_MAPPED_INTEGRITY;
431 }
432}
433
434static void ext_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
435{
436 struct blk_integrity *bi = &rq->q->integrity;
437 unsigned intervals = nr_bytes >> bi->interval_exp;
438 const int tuple_sz = bi->tuple_size;
439 u64 ref_tag = ext_pi_ref_tag(rq);
440 u8 offset = bi->pi_offset;
441 struct bio *bio;
442
443 __rq_for_each_bio(bio, rq) {
444 struct bio_integrity_payload *bip = bio_integrity(bio);
445 u64 virt = lower_48_bits(n: bip_get_seed(bip));
446 struct bio_vec iv;
447 struct bvec_iter iter;
448
449 bip_for_each_vec(iv, bip, iter) {
450 unsigned int j;
451 void *p;
452
453 p = bvec_kmap_local(bvec: &iv);
454 for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
455 struct crc64_pi_tuple *pi = p + offset;
456 u64 ref = get_unaligned_be48(p: pi->ref_tag);
457
458 if (ref == ref_tag)
459 put_unaligned_be48(val: virt, p: pi->ref_tag);
460 virt++;
461 ref_tag++;
462 intervals--;
463 p += tuple_sz;
464 }
465 kunmap_local(p);
466 }
467 }
468}
469
470static blk_status_t ext_pi_type3_verify_crc64(struct blk_integrity_iter *iter)
471{
472 return ext_pi_crc64_verify(iter, type: T10_PI_TYPE3_PROTECTION);
473}
474
475static blk_status_t ext_pi_type3_generate_crc64(struct blk_integrity_iter *iter)
476{
477 return ext_pi_crc64_generate(iter, type: T10_PI_TYPE3_PROTECTION);
478}
479
480const struct blk_integrity_profile ext_pi_type1_crc64 = {
481 .name = "EXT-DIF-TYPE1-CRC64",
482 .generate_fn = ext_pi_type1_generate_crc64,
483 .verify_fn = ext_pi_type1_verify_crc64,
484 .prepare_fn = ext_pi_type1_prepare,
485 .complete_fn = ext_pi_type1_complete,
486};
487EXPORT_SYMBOL_GPL(ext_pi_type1_crc64);
488
489const struct blk_integrity_profile ext_pi_type3_crc64 = {
490 .name = "EXT-DIF-TYPE3-CRC64",
491 .generate_fn = ext_pi_type3_generate_crc64,
492 .verify_fn = ext_pi_type3_verify_crc64,
493 .prepare_fn = t10_pi_type3_prepare,
494 .complete_fn = t10_pi_type3_complete,
495};
496EXPORT_SYMBOL_GPL(ext_pi_type3_crc64);
497
498MODULE_LICENSE("GPL");
499MODULE_LICENSE("GPL");
500

source code of linux/block/t10-pi.c