blob: 4d17f3d35aacff87cde0885cb5cb591e60baca31 [file] [log] [blame]
Martin K. Petersenaf55ff62008-07-17 04:28:35 -04001/*
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 /* Bad ref tag received from disk */
97 if (sdt->ref_tag == 0xffffffff) {
98 printk(KERN_ERR
99 "%s: bad phys ref tag on sector %lu\n",
100 bix->disk_name, (unsigned long)sector);
101 return -EIO;
102 }
103
104 if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
105 printk(KERN_ERR
106 "%s: ref tag error on sector %lu (rcvd %u)\n",
107 bix->disk_name, (unsigned long)sector,
108 be32_to_cpu(sdt->ref_tag));
109 return -EIO;
110 }
111
112 csum = fn(buf, bix->sector_size);
113
114 if (sdt->guard_tag != csum) {
115 printk(KERN_ERR "%s: guard tag error on sector %lu " \
116 "(rcvd %04x, data %04x)\n", bix->disk_name,
117 (unsigned long)sector,
118 be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
119 return -EIO;
120 }
121
122 buf += bix->sector_size;
123 sector++;
124 }
125
126 return 0;
127}
128
129static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
130{
131 return sd_dif_type1_verify(bix, sd_dif_crc_fn);
132}
133
134static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
135{
136 return sd_dif_type1_verify(bix, sd_dif_ip_fn);
137}
138
139/*
140 * Functions for interleaving and deinterleaving application tags
141 */
142static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors)
143{
144 struct sd_dif_tuple *sdt = prot;
145 char *tag = tag_buf;
146 unsigned int i, j;
147
148 for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
149 sdt->app_tag = tag[j] << 8 | tag[j+1];
150 BUG_ON(sdt->app_tag == 0xffff);
151 }
152}
153
154static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors)
155{
156 struct sd_dif_tuple *sdt = prot;
157 char *tag = tag_buf;
158 unsigned int i, j;
159
160 for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
161 tag[j] = (sdt->app_tag & 0xff00) >> 8;
162 tag[j+1] = sdt->app_tag & 0xff;
163 }
164}
165
166static struct blk_integrity dif_type1_integrity_crc = {
167 .name = "T10-DIF-TYPE1-CRC",
168 .generate_fn = sd_dif_type1_generate_crc,
169 .verify_fn = sd_dif_type1_verify_crc,
170 .get_tag_fn = sd_dif_type1_get_tag,
171 .set_tag_fn = sd_dif_type1_set_tag,
172 .tuple_size = sizeof(struct sd_dif_tuple),
173 .tag_size = 0,
174};
175
176static struct blk_integrity dif_type1_integrity_ip = {
177 .name = "T10-DIF-TYPE1-IP",
178 .generate_fn = sd_dif_type1_generate_ip,
179 .verify_fn = sd_dif_type1_verify_ip,
180 .get_tag_fn = sd_dif_type1_get_tag,
181 .set_tag_fn = sd_dif_type1_set_tag,
182 .tuple_size = sizeof(struct sd_dif_tuple),
183 .tag_size = 0,
184};
185
186
187/*
188 * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
189 * tag space.
190 */
191static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
192{
193 void *buf = bix->data_buf;
194 struct sd_dif_tuple *sdt = bix->prot_buf;
195 unsigned int i;
196
197 for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
198 sdt->guard_tag = fn(buf, bix->sector_size);
199 sdt->ref_tag = 0;
200 sdt->app_tag = 0;
201
202 buf += bix->sector_size;
203 }
204}
205
206static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
207{
208 sd_dif_type3_generate(bix, sd_dif_crc_fn);
209}
210
211static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
212{
213 sd_dif_type3_generate(bix, sd_dif_ip_fn);
214}
215
216static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
217{
218 void *buf = bix->data_buf;
219 struct sd_dif_tuple *sdt = bix->prot_buf;
220 sector_t sector = bix->sector;
221 unsigned int i;
222 __u16 csum;
223
224 for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
225 /* Unwritten sectors */
226 if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
227 return 0;
228
229 csum = fn(buf, bix->sector_size);
230
231 if (sdt->guard_tag != csum) {
232 printk(KERN_ERR "%s: guard tag error on sector %lu " \
233 "(rcvd %04x, data %04x)\n", bix->disk_name,
234 (unsigned long)sector,
235 be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
236 return -EIO;
237 }
238
239 buf += bix->sector_size;
240 sector++;
241 }
242
243 return 0;
244}
245
246static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
247{
248 return sd_dif_type3_verify(bix, sd_dif_crc_fn);
249}
250
251static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
252{
253 return sd_dif_type3_verify(bix, sd_dif_ip_fn);
254}
255
256static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors)
257{
258 struct sd_dif_tuple *sdt = prot;
259 char *tag = tag_buf;
260 unsigned int i, j;
261
262 for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) {
263 sdt->app_tag = tag[j] << 8 | tag[j+1];
264 sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 |
265 tag[j+4] << 8 | tag[j+5];
266 }
267}
268
269static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors)
270{
271 struct sd_dif_tuple *sdt = prot;
272 char *tag = tag_buf;
273 unsigned int i, j;
274
275 for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
276 tag[j] = (sdt->app_tag & 0xff00) >> 8;
277 tag[j+1] = sdt->app_tag & 0xff;
278 tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24;
279 tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16;
280 tag[j+4] = (sdt->ref_tag & 0xff00) >> 8;
281 tag[j+5] = sdt->ref_tag & 0xff;
282 BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff);
283 }
284}
285
286static struct blk_integrity dif_type3_integrity_crc = {
287 .name = "T10-DIF-TYPE3-CRC",
288 .generate_fn = sd_dif_type3_generate_crc,
289 .verify_fn = sd_dif_type3_verify_crc,
290 .get_tag_fn = sd_dif_type3_get_tag,
291 .set_tag_fn = sd_dif_type3_set_tag,
292 .tuple_size = sizeof(struct sd_dif_tuple),
293 .tag_size = 0,
294};
295
296static struct blk_integrity dif_type3_integrity_ip = {
297 .name = "T10-DIF-TYPE3-IP",
298 .generate_fn = sd_dif_type3_generate_ip,
299 .verify_fn = sd_dif_type3_verify_ip,
300 .get_tag_fn = sd_dif_type3_get_tag,
301 .set_tag_fn = sd_dif_type3_set_tag,
302 .tuple_size = sizeof(struct sd_dif_tuple),
303 .tag_size = 0,
304};
305
306/*
307 * Configure exchange of protection information between OS and HBA.
308 */
309void sd_dif_config_host(struct scsi_disk *sdkp)
310{
311 struct scsi_device *sdp = sdkp->device;
312 struct gendisk *disk = sdkp->disk;
313 u8 type = sdkp->protection_type;
314
315 /* If this HBA doesn't support DIX, resort to normal I/O or DIF */
316 if (scsi_host_dix_capable(sdp->host, type) == 0) {
317
318 if (type == SD_DIF_TYPE0_PROTECTION)
319 return;
320
321 if (scsi_host_dif_capable(sdp->host, type) == 0) {
322 sd_printk(KERN_INFO, sdkp, "Type %d protection " \
323 "unsupported by HBA. Disabling DIF.\n", type);
324 sdkp->protection_type = 0;
325 return;
326 }
327
328 sd_printk(KERN_INFO, sdkp, "Enabling DIF Type %d protection\n",
329 type);
330
331 return;
332 }
333
334 /* Enable DMA of protection information */
335 if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
336 if (type == SD_DIF_TYPE3_PROTECTION)
337 blk_integrity_register(disk, &dif_type3_integrity_ip);
338 else
339 blk_integrity_register(disk, &dif_type1_integrity_ip);
340 else
341 if (type == SD_DIF_TYPE3_PROTECTION)
342 blk_integrity_register(disk, &dif_type3_integrity_crc);
343 else
344 blk_integrity_register(disk, &dif_type1_integrity_crc);
345
346 sd_printk(KERN_INFO, sdkp,
347 "Enabling %s integrity protection\n", disk->integrity->name);
348
349 /* Signal to block layer that we support sector tagging */
350 if (type && sdkp->ATO) {
351 if (type == SD_DIF_TYPE3_PROTECTION)
352 disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
353 else
354 disk->integrity->tag_size = sizeof(u16);
355
356 sd_printk(KERN_INFO, sdkp, "DIF application tag size %u\n",
357 disk->integrity->tag_size);
358 }
359}
360
361/*
362 * DIF DMA operation magic decoder ring.
363 */
364void sd_dif_op(struct scsi_cmnd *scmd, unsigned int dif, unsigned int dix)
365{
366 int csum_convert, prot_op;
367
368 prot_op = 0;
369
370 /* Convert checksum? */
371 if (scsi_host_get_guard(scmd->device->host) != SHOST_DIX_GUARD_CRC)
372 csum_convert = 1;
373 else
374 csum_convert = 0;
375
376 switch (scmd->cmnd[0]) {
377 case READ_10:
378 case READ_12:
379 case READ_16:
380 if (dif && dix)
381 if (csum_convert)
382 prot_op = SCSI_PROT_READ_CONVERT;
383 else
384 prot_op = SCSI_PROT_READ_PASS;
385 else if (dif && !dix)
386 prot_op = SCSI_PROT_READ_STRIP;
387 else if (!dif && dix)
388 prot_op = SCSI_PROT_READ_INSERT;
389
390 break;
391
392 case WRITE_10:
393 case WRITE_12:
394 case WRITE_16:
395 if (dif && dix)
396 if (csum_convert)
397 prot_op = SCSI_PROT_WRITE_CONVERT;
398 else
399 prot_op = SCSI_PROT_WRITE_PASS;
400 else if (dif && !dix)
401 prot_op = SCSI_PROT_WRITE_INSERT;
402 else if (!dif && dix)
403 prot_op = SCSI_PROT_WRITE_STRIP;
404
405 break;
406 }
407
408 scsi_set_prot_op(scmd, prot_op);
409 scsi_set_prot_type(scmd, dif);
410}
411
412/*
413 * The virtual start sector is the one that was originally submitted
414 * by the block layer. Due to partitioning, MD/DM cloning, etc. the
415 * actual physical start sector is likely to be different. Remap
416 * protection information to match the physical LBA.
417 *
418 * From a protocol perspective there's a slight difference between
419 * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
420 * reference tag is seeded in the CDB. This gives us the potential to
421 * avoid virt->phys remapping during write. However, at read time we
422 * don't know whether the virt sector is the same as when we wrote it
423 * (we could be reading from real disk as opposed to MD/DM device. So
424 * we always remap Type 2 making it identical to Type 1.
425 *
426 * Type 3 does not have a reference tag so no remapping is required.
427 */
428int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_sz)
429{
430 const int tuple_sz = sizeof(struct sd_dif_tuple);
431 struct bio *bio;
432 struct scsi_disk *sdkp;
433 struct sd_dif_tuple *sdt;
434 unsigned int i, j;
435 u32 phys, virt;
436
437 /* Already remapped? */
438 if (rq->cmd_flags & REQ_INTEGRITY)
439 return 0;
440
441 sdkp = rq->bio->bi_bdev->bd_disk->private_data;
442
443 if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
444 return 0;
445
446 rq->cmd_flags |= REQ_INTEGRITY;
447 phys = hw_sector & 0xffffffff;
448
449 __rq_for_each_bio(bio, rq) {
450 struct bio_vec *iv;
451
452 virt = bio->bi_integrity->bip_sector & 0xffffffff;
453
454 bip_for_each_vec(iv, bio->bi_integrity, i) {
455 sdt = kmap_atomic(iv->bv_page, KM_USER0)
456 + iv->bv_offset;
457
458 for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
459
460 if (be32_to_cpu(sdt->ref_tag) != virt)
461 goto error;
462
463 sdt->ref_tag = cpu_to_be32(phys);
464 virt++;
465 phys++;
466 }
467
468 kunmap_atomic(sdt, KM_USER0);
469 }
470 }
471
472 return 0;
473
474error:
475 kunmap_atomic(sdt, KM_USER0);
476 sd_printk(KERN_ERR, sdkp, "%s: virt %u, phys %u, ref %u\n",
477 __func__, virt, phys, be32_to_cpu(sdt->ref_tag));
478
479 return -EIO;
480}
481
482/*
483 * Remap physical sector values in the reference tag to the virtual
484 * values expected by the block layer.
485 */
486void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
487{
488 const int tuple_sz = sizeof(struct sd_dif_tuple);
489 struct scsi_disk *sdkp;
490 struct bio *bio;
491 struct sd_dif_tuple *sdt;
492 unsigned int i, j, sectors, sector_sz;
493 u32 phys, virt;
494
495 sdkp = scsi_disk(scmd->request->rq_disk);
496
497 if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
498 return;
499
500 sector_sz = scmd->device->sector_size;
501 sectors = good_bytes / sector_sz;
502
503 phys = scmd->request->sector & 0xffffffff;
504 if (sector_sz == 4096)
505 phys >>= 3;
506
507 __rq_for_each_bio(bio, scmd->request) {
508 struct bio_vec *iv;
509
510 virt = bio->bi_integrity->bip_sector & 0xffffffff;
511
512 bip_for_each_vec(iv, bio->bi_integrity, i) {
513 sdt = kmap_atomic(iv->bv_page, KM_USER0)
514 + iv->bv_offset;
515
516 for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
517
518 if (sectors == 0) {
519 kunmap_atomic(sdt, KM_USER0);
520 return;
521 }
522
523 if (be32_to_cpu(sdt->ref_tag) != phys &&
524 sdt->app_tag != 0xffff)
525 sdt->ref_tag = 0xffffffff; /* Bad ref */
526 else
527 sdt->ref_tag = cpu_to_be32(virt);
528
529 virt++;
530 phys++;
531 sectors--;
532 }
533
534 kunmap_atomic(sdt, KM_USER0);
535 }
536 }
537}
538