treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers
[sfrench/cifs-2.6.git] / block / t10-pi.c
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/blkdev.h>
9 #include <linux/crc-t10dif.h>
10 #include <net/checksum.h>
11
12 typedef __be16 (csum_fn) (void *, unsigned int);
13
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  */
29 static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
30                 csum_fn *fn, unsigned int type)
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
50         return BLK_STS_OK;
51 }
52
53 static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
54                 csum_fn *fn, unsigned int type)
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:
65                         if (pi->app_tag == T10_PI_APP_ESCAPE)
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));
74                                 return BLK_STS_PROTECTION;
75                         }
76                         break;
77                 case 3:
78                         if (pi->app_tag == T10_PI_APP_ESCAPE &&
79                             pi->ref_tag == T10_PI_REF_ESCAPE)
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));
91                         return BLK_STS_PROTECTION;
92                 }
93
94 next:
95                 iter->data_buf += iter->interval;
96                 iter->prot_buf += sizeof(struct t10_pi_tuple);
97                 iter->seed++;
98         }
99
100         return BLK_STS_OK;
101 }
102
103 static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
104 {
105         return t10_pi_generate(iter, t10_pi_crc_fn, 1);
106 }
107
108 static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
109 {
110         return t10_pi_generate(iter, t10_pi_ip_fn, 1);
111 }
112
113 static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
114 {
115         return t10_pi_verify(iter, t10_pi_crc_fn, 1);
116 }
117
118 static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
119 {
120         return t10_pi_verify(iter, t10_pi_ip_fn, 1);
121 }
122
123 static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
124 {
125         return t10_pi_generate(iter, t10_pi_crc_fn, 3);
126 }
127
128 static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
129 {
130         return t10_pi_generate(iter, t10_pi_ip_fn, 3);
131 }
132
133 static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
134 {
135         return t10_pi_verify(iter, t10_pi_crc_fn, 3);
136 }
137
138 static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
139 {
140         return t10_pi_verify(iter, t10_pi_ip_fn, 3);
141 }
142
143 const struct blk_integrity_profile t10_pi_type1_crc = {
144         .name                   = "T10-DIF-TYPE1-CRC",
145         .generate_fn            = t10_pi_type1_generate_crc,
146         .verify_fn              = t10_pi_type1_verify_crc,
147 };
148 EXPORT_SYMBOL(t10_pi_type1_crc);
149
150 const struct blk_integrity_profile t10_pi_type1_ip = {
151         .name                   = "T10-DIF-TYPE1-IP",
152         .generate_fn            = t10_pi_type1_generate_ip,
153         .verify_fn              = t10_pi_type1_verify_ip,
154 };
155 EXPORT_SYMBOL(t10_pi_type1_ip);
156
157 const struct blk_integrity_profile t10_pi_type3_crc = {
158         .name                   = "T10-DIF-TYPE3-CRC",
159         .generate_fn            = t10_pi_type3_generate_crc,
160         .verify_fn              = t10_pi_type3_verify_crc,
161 };
162 EXPORT_SYMBOL(t10_pi_type3_crc);
163
164 const struct blk_integrity_profile t10_pi_type3_ip = {
165         .name                   = "T10-DIF-TYPE3-IP",
166         .generate_fn            = t10_pi_type3_generate_ip,
167         .verify_fn              = t10_pi_type3_verify_ip,
168 };
169 EXPORT_SYMBOL(t10_pi_type3_ip);
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);