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1/*
2 * sd_dif.c - SCSI Data Integrity Field
3 *
4 * Copyright (C) 2007, 2008 Oracle Corporation
5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; see the file COPYING. If not, write to
18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
19 * USA.
20 *
21 */
22
23#include <linux/blkdev.h>
24#include <linux/crc-t10dif.h>
25
26#include <scsi/scsi.h>
27#include <scsi/scsi_cmnd.h>
28#include <scsi/scsi_dbg.h>
29#include <scsi/scsi_device.h>
30#include <scsi/scsi_driver.h>
31#include <scsi/scsi_eh.h>
32#include <scsi/scsi_host.h>
33#include <scsi/scsi_ioctl.h>
34#include <scsi/scsicam.h>
35
36#include <net/checksum.h>
37
38#include "sd.h"
39
40typedef __u16 (csum_fn) (void *, unsigned int);
41
42static __u16 sd_dif_crc_fn(void *data, unsigned int len)
43{
44 return cpu_to_be16(crc_t10dif(data, len));
45}
46
47static __u16 sd_dif_ip_fn(void *data, unsigned int len)
48{
49 return ip_compute_csum(data, len);
50}
51
52/*
53 * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
54 * 16 bit app tag, 32 bit reference tag.
55 */
56static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
57{
58 void *buf = bix->data_buf;
59 struct sd_dif_tuple *sdt = bix->prot_buf;
60 sector_t sector = bix->sector;
61 unsigned int i;
62
63 for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
64 sdt->guard_tag = fn(buf, bix->sector_size);
65 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
66 sdt->app_tag = 0;
67
68 buf += bix->sector_size;
69 sector++;
70 }
71}
72
73static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix)
74{
75 sd_dif_type1_generate(bix, sd_dif_crc_fn);
76}
77
78static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix)
79{
80 sd_dif_type1_generate(bix, sd_dif_ip_fn);
81}
82
83static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
84{
85 void *buf = bix->data_buf;
86 struct sd_dif_tuple *sdt = bix->prot_buf;
87 sector_t sector = bix->sector;
88 unsigned int i;
89 __u16 csum;
90
91 for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
92 /* Unwritten sectors */
93 if (sdt->app_tag == 0xffff)
94 return 0;
95
96 if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
97 printk(KERN_ERR
98 "%s: ref tag error on sector %lu (rcvd %u)\n",
99 bix->disk_name, (unsigned long)sector,
100 be32_to_cpu(sdt->ref_tag));
101 return -EIO;
102 }
103
104 csum = fn(buf, bix->sector_size);
105
106 if (sdt->guard_tag != csum) {
107 printk(KERN_ERR "%s: guard tag error on sector %lu " \
108 "(rcvd %04x, data %04x)\n", bix->disk_name,
109 (unsigned long)sector,
110 be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
111 return -EIO;
112 }
113
114 buf += bix->sector_size;
115 sector++;
116 }
117
118 return 0;
119}
120
121static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
122{
123 return sd_dif_type1_verify(bix, sd_dif_crc_fn);
124}
125
126static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
127{
128 return sd_dif_type1_verify(bix, sd_dif_ip_fn);
129}
130
131/*
132 * Functions for interleaving and deinterleaving application tags
133 */
134static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors)
135{
136 struct sd_dif_tuple *sdt = prot;
137 u8 *tag = tag_buf;
138 unsigned int i, j;
139
140 for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
141 sdt->app_tag = tag[j] << 8 | tag[j+1];
142 BUG_ON(sdt->app_tag == 0xffff);
143 }
144}
145
146static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors)
147{
148 struct sd_dif_tuple *sdt = prot;
149 u8 *tag = tag_buf;
150 unsigned int i, j;
151
152 for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
153 tag[j] = (sdt->app_tag & 0xff00) >> 8;
154 tag[j+1] = sdt->app_tag & 0xff;
155 }
156}
157
158static struct blk_integrity dif_type1_integrity_crc = {
159 .name = "T10-DIF-TYPE1-CRC",
160 .generate_fn = sd_dif_type1_generate_crc,
161 .verify_fn = sd_dif_type1_verify_crc,
162 .get_tag_fn = sd_dif_type1_get_tag,
163 .set_tag_fn = sd_dif_type1_set_tag,
164 .tuple_size = sizeof(struct sd_dif_tuple),
165 .tag_size = 0,
166};
167
168static struct blk_integrity dif_type1_integrity_ip = {
169 .name = "T10-DIF-TYPE1-IP",
170 .generate_fn = sd_dif_type1_generate_ip,
171 .verify_fn = sd_dif_type1_verify_ip,
172 .get_tag_fn = sd_dif_type1_get_tag,
173 .set_tag_fn = sd_dif_type1_set_tag,
174 .tuple_size = sizeof(struct sd_dif_tuple),
175 .tag_size = 0,
176};
177
178
179/*
180 * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
181 * tag space.
182 */
183static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
184{
185 void *buf = bix->data_buf;
186 struct sd_dif_tuple *sdt = bix->prot_buf;
187 unsigned int i;
188
189 for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
190 sdt->guard_tag = fn(buf, bix->sector_size);
191 sdt->ref_tag = 0;
192 sdt->app_tag = 0;
193
194 buf += bix->sector_size;
195 }
196}
197
198static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
199{
200 sd_dif_type3_generate(bix, sd_dif_crc_fn);
201}
202
203static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
204{
205 sd_dif_type3_generate(bix, sd_dif_ip_fn);
206}
207
208static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
209{
210 void *buf = bix->data_buf;
211 struct sd_dif_tuple *sdt = bix->prot_buf;
212 sector_t sector = bix->sector;
213 unsigned int i;
214 __u16 csum;
215
216 for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
217 /* Unwritten sectors */
218 if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
219 return 0;
220
221 csum = fn(buf, bix->sector_size);
222
223 if (sdt->guard_tag != csum) {
224 printk(KERN_ERR "%s: guard tag error on sector %lu " \
225 "(rcvd %04x, data %04x)\n", bix->disk_name,
226 (unsigned long)sector,
227 be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
228 return -EIO;
229 }
230
231 buf += bix->sector_size;
232 sector++;
233 }
234
235 return 0;
236}
237
238static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
239{
240 return sd_dif_type3_verify(bix, sd_dif_crc_fn);
241}
242
243static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
244{
245 return sd_dif_type3_verify(bix, sd_dif_ip_fn);
246}
247
248static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors)
249{
250 struct sd_dif_tuple *sdt = prot;
251 u8 *tag = tag_buf;
252 unsigned int i, j;
253
254 for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) {
255 sdt->app_tag = tag[j] << 8 | tag[j+1];
256 sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 |
257 tag[j+4] << 8 | tag[j+5];
258 }
259}
260
261static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors)
262{
263 struct sd_dif_tuple *sdt = prot;
264 u8 *tag = tag_buf;
265 unsigned int i, j;
266
267 for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
268 tag[j] = (sdt->app_tag & 0xff00) >> 8;
269 tag[j+1] = sdt->app_tag & 0xff;
270 tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24;
271 tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16;
272 tag[j+4] = (sdt->ref_tag & 0xff00) >> 8;
273 tag[j+5] = sdt->ref_tag & 0xff;
274 BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff);
275 }
276}
277
278static struct blk_integrity dif_type3_integrity_crc = {
279 .name = "T10-DIF-TYPE3-CRC",
280 .generate_fn = sd_dif_type3_generate_crc,
281 .verify_fn = sd_dif_type3_verify_crc,
282 .get_tag_fn = sd_dif_type3_get_tag,
283 .set_tag_fn = sd_dif_type3_set_tag,
284 .tuple_size = sizeof(struct sd_dif_tuple),
285 .tag_size = 0,
286};
287
288static struct blk_integrity dif_type3_integrity_ip = {
289 .name = "T10-DIF-TYPE3-IP",
290 .generate_fn = sd_dif_type3_generate_ip,
291 .verify_fn = sd_dif_type3_verify_ip,
292 .get_tag_fn = sd_dif_type3_get_tag,
293 .set_tag_fn = sd_dif_type3_set_tag,
294 .tuple_size = sizeof(struct sd_dif_tuple),
295 .tag_size = 0,
296};
297
298/*
299 * Configure exchange of protection information between OS and HBA.
300 */
301void sd_dif_config_host(struct scsi_disk *sdkp)
302{
303 struct scsi_device *sdp = sdkp->device;
304 struct gendisk *disk = sdkp->disk;
305 u8 type = sdkp->protection_type;
306 int dif, dix;
307
308 dif = scsi_host_dif_capable(sdp->host, type);
309 dix = scsi_host_dix_capable(sdp->host, type);
310
311 if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
312 dif = 0; dix = 1;
313 }
314
315 if (!dix)
316 return;
317
318 /* Enable DMA of protection information */
319 if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
320 if (type == SD_DIF_TYPE3_PROTECTION)
321 blk_integrity_register(disk, &dif_type3_integrity_ip);
322 else
323 blk_integrity_register(disk, &dif_type1_integrity_ip);
324 else
325 if (type == SD_DIF_TYPE3_PROTECTION)
326 blk_integrity_register(disk, &dif_type3_integrity_crc);
327 else
328 blk_integrity_register(disk, &dif_type1_integrity_crc);
329
330 sd_printk(KERN_NOTICE, sdkp,
331 "Enabling DIX %s protection\n", disk->integrity->name);
332
333 /* Signal to block layer that we support sector tagging */
334 if (dif && type && sdkp->ATO) {
335 if (type == SD_DIF_TYPE3_PROTECTION)
336 disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
337 else
338 disk->integrity->tag_size = sizeof(u16);
339
340 sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
341 disk->integrity->tag_size);
342 }
343}
344
345/*
346 * The virtual start sector is the one that was originally submitted
347 * by the block layer. Due to partitioning, MD/DM cloning, etc. the
348 * actual physical start sector is likely to be different. Remap
349 * protection information to match the physical LBA.
350 *
351 * From a protocol perspective there's a slight difference between
352 * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
353 * reference tag is seeded in the CDB. This gives us the potential to
354 * avoid virt->phys remapping during write. However, at read time we
355 * don't know whether the virt sector is the same as when we wrote it
356 * (we could be reading from real disk as opposed to MD/DM device. So
357 * we always remap Type 2 making it identical to Type 1.
358 *
359 * Type 3 does not have a reference tag so no remapping is required.
360 */
361void sd_dif_prepare(struct request *rq, sector_t hw_sector,
362 unsigned int sector_sz)
363{
364 const int tuple_sz = sizeof(struct sd_dif_tuple);
365 struct bio *bio;
366 struct scsi_disk *sdkp;
367 struct sd_dif_tuple *sdt;
368 u32 phys, virt;
369
370 sdkp = rq->bio->bi_bdev->bd_disk->private_data;
371
372 if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
373 return;
374
375 phys = hw_sector & 0xffffffff;
376
377 __rq_for_each_bio(bio, rq) {
378 struct bio_vec iv;
379 struct bvec_iter iter;
380 unsigned int j;
381
382 /* Already remapped? */
383 if (bio_flagged(bio, BIO_MAPPED_INTEGRITY))
384 break;
385
386 virt = bio->bi_integrity->bip_iter.bi_sector & 0xffffffff;
387
388 bip_for_each_vec(iv, bio->bi_integrity, iter) {
389 sdt = kmap_atomic(iv.bv_page)
390 + iv.bv_offset;
391
392 for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {
393
394 if (be32_to_cpu(sdt->ref_tag) == virt)
395 sdt->ref_tag = cpu_to_be32(phys);
396
397 virt++;
398 phys++;
399 }
400
401 kunmap_atomic(sdt);
402 }
403
404 bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY);
405 }
406}
407
408/*
409 * Remap physical sector values in the reference tag to the virtual
410 * values expected by the block layer.
411 */
412void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
413{
414 const int tuple_sz = sizeof(struct sd_dif_tuple);
415 struct scsi_disk *sdkp;
416 struct bio *bio;
417 struct sd_dif_tuple *sdt;
418 unsigned int j, sectors, sector_sz;
419 u32 phys, virt;
420
421 sdkp = scsi_disk(scmd->request->rq_disk);
422
423 if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
424 return;
425
426 sector_sz = scmd->device->sector_size;
427 sectors = good_bytes / sector_sz;
428
429 phys = blk_rq_pos(scmd->request) & 0xffffffff;
430 if (sector_sz == 4096)
431 phys >>= 3;
432
433 __rq_for_each_bio(bio, scmd->request) {
434 struct bio_vec iv;
435 struct bvec_iter iter;
436
437 virt = bio->bi_integrity->bip_iter.bi_sector & 0xffffffff;
438
439 bip_for_each_vec(iv, bio->bi_integrity, iter) {
440 sdt = kmap_atomic(iv.bv_page)
441 + iv.bv_offset;
442
443 for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {
444
445 if (sectors == 0) {
446 kunmap_atomic(sdt);
447 return;
448 }
449
450 if (be32_to_cpu(sdt->ref_tag) == phys)
451 sdt->ref_tag = cpu_to_be32(virt);
452
453 virt++;
454 phys++;
455 sectors--;
456 }
457
458 kunmap_atomic(sdt);
459 }
460 }
461}
462
1/*
2 * sd_dif.c - SCSI Data Integrity Field
3 *
4 * Copyright (C) 2007, 2008 Oracle Corporation
5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; see the file COPYING. If not, write to
18 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
19 * USA.
20 *
21 */
22
23#include <linux/blkdev.h>
24#include <linux/t10-pi.h>
25
26#include <scsi/scsi.h>
27#include <scsi/scsi_cmnd.h>
28#include <scsi/scsi_dbg.h>
29#include <scsi/scsi_device.h>
30#include <scsi/scsi_driver.h>
31#include <scsi/scsi_eh.h>
32#include <scsi/scsi_host.h>
33#include <scsi/scsi_ioctl.h>
34#include <scsi/scsicam.h>
35
36#include "sd.h"
37
38/*
39 * Configure exchange of protection information between OS and HBA.
40 */
41void sd_dif_config_host(struct scsi_disk *sdkp)
42{
43 struct scsi_device *sdp = sdkp->device;
44 struct gendisk *disk = sdkp->disk;
45 u8 type = sdkp->protection_type;
46 struct blk_integrity bi;
47 int dif, dix;
48
49 dif = scsi_host_dif_capable(sdp->host, type);
50 dix = scsi_host_dix_capable(sdp->host, type);
51
52 if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
53 dif = 0; dix = 1;
54 }
55
56 if (!dix)
57 return;
58
59 memset(&bi, 0, sizeof(bi));
60
61 /* Enable DMA of protection information */
62 if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) {
63 if (type == T10_PI_TYPE3_PROTECTION)
64 bi.profile = &t10_pi_type3_ip;
65 else
66 bi.profile = &t10_pi_type1_ip;
67
68 bi.flags |= BLK_INTEGRITY_IP_CHECKSUM;
69 } else
70 if (type == T10_PI_TYPE3_PROTECTION)
71 bi.profile = &t10_pi_type3_crc;
72 else
73 bi.profile = &t10_pi_type1_crc;
74
75 bi.tuple_size = sizeof(struct t10_pi_tuple);
76 sd_printk(KERN_NOTICE, sdkp,
77 "Enabling DIX %s protection\n", bi.profile->name);
78
79 if (dif && type) {
80 bi.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
81
82 if (!sdkp->ATO)
83 goto out;
84
85 if (type == T10_PI_TYPE3_PROTECTION)
86 bi.tag_size = sizeof(u16) + sizeof(u32);
87 else
88 bi.tag_size = sizeof(u16);
89
90 sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
91 bi.tag_size);
92 }
93
94out:
95 blk_integrity_register(disk, &bi);
96}
97
98/*
99 * The virtual start sector is the one that was originally submitted
100 * by the block layer. Due to partitioning, MD/DM cloning, etc. the
101 * actual physical start sector is likely to be different. Remap
102 * protection information to match the physical LBA.
103 *
104 * From a protocol perspective there's a slight difference between
105 * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
106 * reference tag is seeded in the CDB. This gives us the potential to
107 * avoid virt->phys remapping during write. However, at read time we
108 * don't know whether the virt sector is the same as when we wrote it
109 * (we could be reading from real disk as opposed to MD/DM device. So
110 * we always remap Type 2 making it identical to Type 1.
111 *
112 * Type 3 does not have a reference tag so no remapping is required.
113 */
114void sd_dif_prepare(struct scsi_cmnd *scmd)
115{
116 const int tuple_sz = sizeof(struct t10_pi_tuple);
117 struct bio *bio;
118 struct scsi_disk *sdkp;
119 struct t10_pi_tuple *pi;
120 u32 phys, virt;
121
122 sdkp = scsi_disk(scmd->request->rq_disk);
123
124 if (sdkp->protection_type == T10_PI_TYPE3_PROTECTION)
125 return;
126
127 phys = scsi_prot_ref_tag(scmd);
128
129 __rq_for_each_bio(bio, scmd->request) {
130 struct bio_integrity_payload *bip = bio_integrity(bio);
131 struct bio_vec iv;
132 struct bvec_iter iter;
133 unsigned int j;
134
135 /* Already remapped? */
136 if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
137 break;
138
139 virt = bip_get_seed(bip) & 0xffffffff;
140
141 bip_for_each_vec(iv, bip, iter) {
142 pi = kmap_atomic(iv.bv_page) + iv.bv_offset;
143
144 for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {
145
146 if (be32_to_cpu(pi->ref_tag) == virt)
147 pi->ref_tag = cpu_to_be32(phys);
148
149 virt++;
150 phys++;
151 }
152
153 kunmap_atomic(pi);
154 }
155
156 bip->bip_flags |= BIP_MAPPED_INTEGRITY;
157 }
158}
159
160/*
161 * Remap physical sector values in the reference tag to the virtual
162 * values expected by the block layer.
163 */
164void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
165{
166 const int tuple_sz = sizeof(struct t10_pi_tuple);
167 struct scsi_disk *sdkp;
168 struct bio *bio;
169 struct t10_pi_tuple *pi;
170 unsigned int j, intervals;
171 u32 phys, virt;
172
173 sdkp = scsi_disk(scmd->request->rq_disk);
174
175 if (sdkp->protection_type == T10_PI_TYPE3_PROTECTION || good_bytes == 0)
176 return;
177
178 intervals = good_bytes / scsi_prot_interval(scmd);
179 phys = scsi_prot_ref_tag(scmd);
180
181 __rq_for_each_bio(bio, scmd->request) {
182 struct bio_integrity_payload *bip = bio_integrity(bio);
183 struct bio_vec iv;
184 struct bvec_iter iter;
185
186 virt = bip_get_seed(bip) & 0xffffffff;
187
188 bip_for_each_vec(iv, bip, iter) {
189 pi = kmap_atomic(iv.bv_page) + iv.bv_offset;
190
191 for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {
192
193 if (intervals == 0) {
194 kunmap_atomic(pi);
195 return;
196 }
197
198 if (be32_to_cpu(pi->ref_tag) == phys)
199 pi->ref_tag = cpu_to_be32(virt);
200
201 virt++;
202 phys++;
203 intervals--;
204 }
205
206 kunmap_atomic(pi);
207 }
208 }
209}
210