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) (void *, unsigned int);
16
17static __be16 t10_pi_crc_fn(void *data, unsigned int len)
18{
19 return cpu_to_be16(crc_t10dif(data, len));
20}
21
22static __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 */
32static 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
56static 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
96next:
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
105static 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
110static 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
115static 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
120static 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 */
135static 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 */
184static 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
217static 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
222static 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
227static 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
232static 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. */
238static 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. */
243static void t10_pi_type3_complete(struct request *rq, unsigned int nr_bytes)
244{
245}
246
247const 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};
254EXPORT_SYMBOL(t10_pi_type1_crc);
255
256const 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};
263EXPORT_SYMBOL(t10_pi_type1_ip);
264
265const 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};
272EXPORT_SYMBOL(t10_pi_type3_crc);
273
274const 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};
281EXPORT_SYMBOL(t10_pi_type3_ip);
282
283static __be64 ext_pi_crc64(void *data, unsigned int len)
284{
285 return cpu_to_be64(crc64_rocksoft(data, len));
286}
287
288static 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
312static 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
319static 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
355next:
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
364static 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
369static 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
374static 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
412static 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
446static 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
451static 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
456const 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};
463EXPORT_SYMBOL_GPL(ext_pi_type1_crc64);
464
465const 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};
472EXPORT_SYMBOL_GPL(ext_pi_type3_crc64);
473
474MODULE_LICENSE("GPL");
475MODULE_LICENSE("GPL");
476

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