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 <linux/module.h>
11 #include <net/checksum.h>
12
13 typedef __be16 (csum_fn) (void *, unsigned int);
14
t10_pi_crc_fn(void * data,unsigned int len)15 static __be16 t10_pi_crc_fn(void *data, unsigned int len)
16 {
17 return cpu_to_be16(crc_t10dif(data, len));
18 }
19
t10_pi_ip_fn(void * data,unsigned int len)20 static __be16 t10_pi_ip_fn(void *data, unsigned int len)
21 {
22 return (__force __be16)ip_compute_csum(data, len);
23 }
24
25 /*
26 * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
27 * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
28 * tag.
29 */
t10_pi_generate(struct blk_integrity_iter * iter,csum_fn * fn,enum t10_dif_type type)30 static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
31 csum_fn *fn, enum t10_dif_type type)
32 {
33 unsigned int i;
34
35 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
36 struct t10_pi_tuple *pi = iter->prot_buf;
37
38 pi->guard_tag = fn(iter->data_buf, iter->interval);
39 pi->app_tag = 0;
40
41 if (type == T10_PI_TYPE1_PROTECTION)
42 pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
43 else
44 pi->ref_tag = 0;
45
46 iter->data_buf += iter->interval;
47 iter->prot_buf += sizeof(struct t10_pi_tuple);
48 iter->seed++;
49 }
50
51 return BLK_STS_OK;
52 }
53
t10_pi_verify(struct blk_integrity_iter * iter,csum_fn * fn,enum t10_dif_type type)54 static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
55 csum_fn *fn, enum t10_dif_type type)
56 {
57 unsigned int i;
58
59 BUG_ON(type == T10_PI_TYPE0_PROTECTION);
60
61 for (i = 0 ; i < iter->data_size ; i += iter->interval) {
62 struct t10_pi_tuple *pi = iter->prot_buf;
63 __be16 csum;
64
65 if (type == T10_PI_TYPE1_PROTECTION ||
66 type == T10_PI_TYPE2_PROTECTION) {
67 if (pi->app_tag == T10_PI_APP_ESCAPE)
68 goto next;
69
70 if (be32_to_cpu(pi->ref_tag) !=
71 lower_32_bits(iter->seed)) {
72 pr_err("%s: ref tag error at location %llu " \
73 "(rcvd %u)\n", iter->disk_name,
74 (unsigned long long)
75 iter->seed, be32_to_cpu(pi->ref_tag));
76 return BLK_STS_PROTECTION;
77 }
78 } else if (type == T10_PI_TYPE3_PROTECTION) {
79 if (pi->app_tag == T10_PI_APP_ESCAPE &&
80 pi->ref_tag == T10_PI_REF_ESCAPE)
81 goto next;
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
t10_pi_type1_generate_crc(struct blk_integrity_iter * iter)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, T10_PI_TYPE1_PROTECTION);
106 }
107
t10_pi_type1_generate_ip(struct blk_integrity_iter * iter)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, T10_PI_TYPE1_PROTECTION);
111 }
112
t10_pi_type1_verify_crc(struct blk_integrity_iter * iter)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, T10_PI_TYPE1_PROTECTION);
116 }
117
t10_pi_type1_verify_ip(struct blk_integrity_iter * iter)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, T10_PI_TYPE1_PROTECTION);
121 }
122
123 /**
124 * t10_pi_type1_prepare - prepare PI prior submitting request to device
125 * @rq: request with PI that should be prepared
126 *
127 * For Type 1/Type 2, the virtual start sector is the one that was
128 * originally submitted by the block layer for the ref_tag usage. Due to
129 * partitioning, MD/DM cloning, etc. the actual physical start sector is
130 * likely to be different. Remap protection information to match the
131 * physical LBA.
132 */
t10_pi_type1_prepare(struct request * rq)133 static void t10_pi_type1_prepare(struct request *rq)
134 {
135 const int tuple_sz = rq->q->integrity.tuple_size;
136 u32 ref_tag = t10_pi_ref_tag(rq);
137 struct bio *bio;
138
139 __rq_for_each_bio(bio, rq) {
140 struct bio_integrity_payload *bip = bio_integrity(bio);
141 u32 virt = bip_get_seed(bip) & 0xffffffff;
142 struct bio_vec iv;
143 struct bvec_iter iter;
144
145 /* Already remapped? */
146 if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
147 break;
148
149 bip_for_each_vec(iv, bip, iter) {
150 unsigned int j;
151 void *p;
152
153 p = bvec_kmap_local(&iv);
154 for (j = 0; j < iv.bv_len; j += tuple_sz) {
155 struct t10_pi_tuple *pi = p;
156
157 if (be32_to_cpu(pi->ref_tag) == virt)
158 pi->ref_tag = cpu_to_be32(ref_tag);
159 virt++;
160 ref_tag++;
161 p += tuple_sz;
162 }
163 kunmap_local(p);
164 }
165
166 bip->bip_flags |= BIP_MAPPED_INTEGRITY;
167 }
168 }
169
170 /**
171 * t10_pi_type1_complete - prepare PI prior returning request to the blk layer
172 * @rq: request with PI that should be prepared
173 * @nr_bytes: total bytes to prepare
174 *
175 * For Type 1/Type 2, the virtual start sector is the one that was
176 * originally submitted by the block layer for the ref_tag usage. Due to
177 * partitioning, MD/DM cloning, etc. the actual physical start sector is
178 * likely to be different. Since the physical start sector was submitted
179 * to the device, we should remap it back to virtual values expected by the
180 * block layer.
181 */
t10_pi_type1_complete(struct request * rq,unsigned int nr_bytes)182 static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes)
183 {
184 unsigned intervals = nr_bytes >> rq->q->integrity.interval_exp;
185 const int tuple_sz = rq->q->integrity.tuple_size;
186 u32 ref_tag = t10_pi_ref_tag(rq);
187 struct bio *bio;
188
189 __rq_for_each_bio(bio, rq) {
190 struct bio_integrity_payload *bip = bio_integrity(bio);
191 u32 virt = bip_get_seed(bip) & 0xffffffff;
192 struct bio_vec iv;
193 struct bvec_iter iter;
194
195 bip_for_each_vec(iv, bip, iter) {
196 unsigned int j;
197 void *p;
198
199 p = bvec_kmap_local(&iv);
200 for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
201 struct t10_pi_tuple *pi = p;
202
203 if (be32_to_cpu(pi->ref_tag) == ref_tag)
204 pi->ref_tag = cpu_to_be32(virt);
205 virt++;
206 ref_tag++;
207 intervals--;
208 p += tuple_sz;
209 }
210 kunmap_local(p);
211 }
212 }
213 }
214
t10_pi_type3_generate_crc(struct blk_integrity_iter * iter)215 static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
216 {
217 return t10_pi_generate(iter, t10_pi_crc_fn, T10_PI_TYPE3_PROTECTION);
218 }
219
t10_pi_type3_generate_ip(struct blk_integrity_iter * iter)220 static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
221 {
222 return t10_pi_generate(iter, t10_pi_ip_fn, T10_PI_TYPE3_PROTECTION);
223 }
224
t10_pi_type3_verify_crc(struct blk_integrity_iter * iter)225 static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
226 {
227 return t10_pi_verify(iter, t10_pi_crc_fn, T10_PI_TYPE3_PROTECTION);
228 }
229
t10_pi_type3_verify_ip(struct blk_integrity_iter * iter)230 static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
231 {
232 return t10_pi_verify(iter, t10_pi_ip_fn, T10_PI_TYPE3_PROTECTION);
233 }
234
235 /* Type 3 does not have a reference tag so no remapping is required. */
t10_pi_type3_prepare(struct request * rq)236 static void t10_pi_type3_prepare(struct request *rq)
237 {
238 }
239
240 /* Type 3 does not have a reference tag so no remapping is required. */
t10_pi_type3_complete(struct request * rq,unsigned int nr_bytes)241 static void t10_pi_type3_complete(struct request *rq, unsigned int nr_bytes)
242 {
243 }
244
245 const struct blk_integrity_profile t10_pi_type1_crc = {
246 .name = "T10-DIF-TYPE1-CRC",
247 .generate_fn = t10_pi_type1_generate_crc,
248 .verify_fn = t10_pi_type1_verify_crc,
249 .prepare_fn = t10_pi_type1_prepare,
250 .complete_fn = t10_pi_type1_complete,
251 };
252 EXPORT_SYMBOL(t10_pi_type1_crc);
253
254 const struct blk_integrity_profile t10_pi_type1_ip = {
255 .name = "T10-DIF-TYPE1-IP",
256 .generate_fn = t10_pi_type1_generate_ip,
257 .verify_fn = t10_pi_type1_verify_ip,
258 .prepare_fn = t10_pi_type1_prepare,
259 .complete_fn = t10_pi_type1_complete,
260 };
261 EXPORT_SYMBOL(t10_pi_type1_ip);
262
263 const struct blk_integrity_profile t10_pi_type3_crc = {
264 .name = "T10-DIF-TYPE3-CRC",
265 .generate_fn = t10_pi_type3_generate_crc,
266 .verify_fn = t10_pi_type3_verify_crc,
267 .prepare_fn = t10_pi_type3_prepare,
268 .complete_fn = t10_pi_type3_complete,
269 };
270 EXPORT_SYMBOL(t10_pi_type3_crc);
271
272 const struct blk_integrity_profile t10_pi_type3_ip = {
273 .name = "T10-DIF-TYPE3-IP",
274 .generate_fn = t10_pi_type3_generate_ip,
275 .verify_fn = t10_pi_type3_verify_ip,
276 .prepare_fn = t10_pi_type3_prepare,
277 .complete_fn = t10_pi_type3_complete,
278 };
279 EXPORT_SYMBOL(t10_pi_type3_ip);
280
281 MODULE_LICENSE("GPL");
282