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af55ff67 MP |
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 | ||
40 | typedef __u16 (csum_fn) (void *, unsigned int); | |
41 | ||
42 | static __u16 sd_dif_crc_fn(void *data, unsigned int len) | |
43 | { | |
44 | return cpu_to_be16(crc_t10dif(data, len)); | |
45 | } | |
46 | ||
47 | static __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 | */ | |
56 | static 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 | ||
73 | static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix) | |
74 | { | |
75 | sd_dif_type1_generate(bix, sd_dif_crc_fn); | |
76 | } | |
77 | ||
78 | static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix) | |
79 | { | |
80 | sd_dif_type1_generate(bix, sd_dif_ip_fn); | |
81 | } | |
82 | ||
83 | static 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 | ||
129 | static 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 | ||
134 | static 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 | */ | |
142 | static 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 | ||
154 | static 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 | ||
166 | static 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 | ||
176 | static 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 | */ | |
191 | static 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 | ||
206 | static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix) | |
207 | { | |
208 | sd_dif_type3_generate(bix, sd_dif_crc_fn); | |
209 | } | |
210 | ||
211 | static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix) | |
212 | { | |
213 | sd_dif_type3_generate(bix, sd_dif_ip_fn); | |
214 | } | |
215 | ||
216 | static 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 | ||
246 | static 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 | ||
251 | static 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 | ||
256 | static 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 | ||
269 | static 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 | ||
286 | static 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 | ||
296 | static 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 | */ | |
309 | void 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; | |
9e06688e | 314 | int dif, dix; |
af55ff67 | 315 | |
9e06688e MP |
316 | dif = scsi_host_dif_capable(sdp->host, type); |
317 | dix = scsi_host_dix_capable(sdp->host, type); | |
af55ff67 | 318 | |
9e06688e MP |
319 | if (!dix && scsi_host_dix_capable(sdp->host, 0)) { |
320 | dif = 0; dix = 1; | |
321 | } | |
af55ff67 | 322 | |
9e06688e MP |
323 | if (type) { |
324 | if (dif) | |
cbdc1445 | 325 | sd_printk(KERN_NOTICE, sdkp, |
9e06688e MP |
326 | "Enabling DIF Type %d protection\n", type); |
327 | else | |
cbdc1445 | 328 | sd_printk(KERN_NOTICE, sdkp, |
9e06688e MP |
329 | "Disabling DIF Type %d protection\n", type); |
330 | } | |
af55ff67 | 331 | |
9e06688e | 332 | if (!dix) |
af55ff67 | 333 | return; |
af55ff67 MP |
334 | |
335 | /* Enable DMA of protection information */ | |
336 | if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) | |
337 | if (type == SD_DIF_TYPE3_PROTECTION) | |
338 | blk_integrity_register(disk, &dif_type3_integrity_ip); | |
339 | else | |
340 | blk_integrity_register(disk, &dif_type1_integrity_ip); | |
341 | else | |
342 | if (type == SD_DIF_TYPE3_PROTECTION) | |
343 | blk_integrity_register(disk, &dif_type3_integrity_crc); | |
344 | else | |
345 | blk_integrity_register(disk, &dif_type1_integrity_crc); | |
346 | ||
cbdc1445 | 347 | sd_printk(KERN_NOTICE, sdkp, |
9e06688e | 348 | "Enabling DIX %s protection\n", disk->integrity->name); |
af55ff67 MP |
349 | |
350 | /* Signal to block layer that we support sector tagging */ | |
9e06688e | 351 | if (dif && type && sdkp->ATO) { |
af55ff67 MP |
352 | if (type == SD_DIF_TYPE3_PROTECTION) |
353 | disk->integrity->tag_size = sizeof(u16) + sizeof(u32); | |
354 | else | |
355 | disk->integrity->tag_size = sizeof(u16); | |
356 | ||
cbdc1445 | 357 | sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n", |
af55ff67 MP |
358 | disk->integrity->tag_size); |
359 | } | |
360 | } | |
361 | ||
362 | /* | |
363 | * DIF DMA operation magic decoder ring. | |
364 | */ | |
9e06688e | 365 | void sd_dif_op(struct scsi_cmnd *scmd, unsigned int dif, unsigned int dix, unsigned int type) |
af55ff67 MP |
366 | { |
367 | int csum_convert, prot_op; | |
368 | ||
369 | prot_op = 0; | |
370 | ||
371 | /* Convert checksum? */ | |
372 | if (scsi_host_get_guard(scmd->device->host) != SHOST_DIX_GUARD_CRC) | |
373 | csum_convert = 1; | |
374 | else | |
375 | csum_convert = 0; | |
376 | ||
377 | switch (scmd->cmnd[0]) { | |
378 | case READ_10: | |
379 | case READ_12: | |
380 | case READ_16: | |
381 | if (dif && dix) | |
382 | if (csum_convert) | |
383 | prot_op = SCSI_PROT_READ_CONVERT; | |
384 | else | |
385 | prot_op = SCSI_PROT_READ_PASS; | |
386 | else if (dif && !dix) | |
387 | prot_op = SCSI_PROT_READ_STRIP; | |
388 | else if (!dif && dix) | |
389 | prot_op = SCSI_PROT_READ_INSERT; | |
390 | ||
391 | break; | |
392 | ||
393 | case WRITE_10: | |
394 | case WRITE_12: | |
395 | case WRITE_16: | |
396 | if (dif && dix) | |
397 | if (csum_convert) | |
398 | prot_op = SCSI_PROT_WRITE_CONVERT; | |
399 | else | |
400 | prot_op = SCSI_PROT_WRITE_PASS; | |
401 | else if (dif && !dix) | |
402 | prot_op = SCSI_PROT_WRITE_INSERT; | |
403 | else if (!dif && dix) | |
404 | prot_op = SCSI_PROT_WRITE_STRIP; | |
405 | ||
406 | break; | |
407 | } | |
408 | ||
409 | scsi_set_prot_op(scmd, prot_op); | |
9e06688e MP |
410 | if (dif) |
411 | scsi_set_prot_type(scmd, type); | |
af55ff67 MP |
412 | } |
413 | ||
414 | /* | |
415 | * The virtual start sector is the one that was originally submitted | |
416 | * by the block layer. Due to partitioning, MD/DM cloning, etc. the | |
417 | * actual physical start sector is likely to be different. Remap | |
418 | * protection information to match the physical LBA. | |
419 | * | |
420 | * From a protocol perspective there's a slight difference between | |
421 | * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the | |
422 | * reference tag is seeded in the CDB. This gives us the potential to | |
423 | * avoid virt->phys remapping during write. However, at read time we | |
424 | * don't know whether the virt sector is the same as when we wrote it | |
425 | * (we could be reading from real disk as opposed to MD/DM device. So | |
426 | * we always remap Type 2 making it identical to Type 1. | |
427 | * | |
428 | * Type 3 does not have a reference tag so no remapping is required. | |
429 | */ | |
430 | int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_sz) | |
431 | { | |
432 | const int tuple_sz = sizeof(struct sd_dif_tuple); | |
433 | struct bio *bio; | |
434 | struct scsi_disk *sdkp; | |
435 | struct sd_dif_tuple *sdt; | |
436 | unsigned int i, j; | |
437 | u32 phys, virt; | |
438 | ||
439 | /* Already remapped? */ | |
440 | if (rq->cmd_flags & REQ_INTEGRITY) | |
441 | return 0; | |
442 | ||
443 | sdkp = rq->bio->bi_bdev->bd_disk->private_data; | |
444 | ||
445 | if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION) | |
446 | return 0; | |
447 | ||
448 | rq->cmd_flags |= REQ_INTEGRITY; | |
449 | phys = hw_sector & 0xffffffff; | |
450 | ||
451 | __rq_for_each_bio(bio, rq) { | |
452 | struct bio_vec *iv; | |
453 | ||
454 | virt = bio->bi_integrity->bip_sector & 0xffffffff; | |
455 | ||
456 | bip_for_each_vec(iv, bio->bi_integrity, i) { | |
457 | sdt = kmap_atomic(iv->bv_page, KM_USER0) | |
458 | + iv->bv_offset; | |
459 | ||
460 | for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) { | |
461 | ||
462 | if (be32_to_cpu(sdt->ref_tag) != virt) | |
463 | goto error; | |
464 | ||
465 | sdt->ref_tag = cpu_to_be32(phys); | |
466 | virt++; | |
467 | phys++; | |
468 | } | |
469 | ||
470 | kunmap_atomic(sdt, KM_USER0); | |
471 | } | |
472 | } | |
473 | ||
474 | return 0; | |
475 | ||
476 | error: | |
477 | kunmap_atomic(sdt, KM_USER0); | |
478 | sd_printk(KERN_ERR, sdkp, "%s: virt %u, phys %u, ref %u\n", | |
479 | __func__, virt, phys, be32_to_cpu(sdt->ref_tag)); | |
480 | ||
481 | return -EIO; | |
482 | } | |
483 | ||
484 | /* | |
485 | * Remap physical sector values in the reference tag to the virtual | |
486 | * values expected by the block layer. | |
487 | */ | |
488 | void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes) | |
489 | { | |
490 | const int tuple_sz = sizeof(struct sd_dif_tuple); | |
491 | struct scsi_disk *sdkp; | |
492 | struct bio *bio; | |
493 | struct sd_dif_tuple *sdt; | |
494 | unsigned int i, j, sectors, sector_sz; | |
495 | u32 phys, virt; | |
496 | ||
497 | sdkp = scsi_disk(scmd->request->rq_disk); | |
498 | ||
499 | if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0) | |
500 | return; | |
501 | ||
502 | sector_sz = scmd->device->sector_size; | |
503 | sectors = good_bytes / sector_sz; | |
504 | ||
505 | phys = scmd->request->sector & 0xffffffff; | |
506 | if (sector_sz == 4096) | |
507 | phys >>= 3; | |
508 | ||
509 | __rq_for_each_bio(bio, scmd->request) { | |
510 | struct bio_vec *iv; | |
511 | ||
512 | virt = bio->bi_integrity->bip_sector & 0xffffffff; | |
513 | ||
514 | bip_for_each_vec(iv, bio->bi_integrity, i) { | |
515 | sdt = kmap_atomic(iv->bv_page, KM_USER0) | |
516 | + iv->bv_offset; | |
517 | ||
518 | for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) { | |
519 | ||
520 | if (sectors == 0) { | |
521 | kunmap_atomic(sdt, KM_USER0); | |
522 | return; | |
523 | } | |
524 | ||
525 | if (be32_to_cpu(sdt->ref_tag) != phys && | |
526 | sdt->app_tag != 0xffff) | |
527 | sdt->ref_tag = 0xffffffff; /* Bad ref */ | |
528 | else | |
529 | sdt->ref_tag = cpu_to_be32(virt); | |
530 | ||
531 | virt++; | |
532 | phys++; | |
533 | sectors--; | |
534 | } | |
535 | ||
536 | kunmap_atomic(sdt, KM_USER0); | |
537 | } | |
538 | } | |
539 | } | |
540 |