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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 | ||
af55ff67 MP |
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 | ||
121 | static 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 | ||
126 | static 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 | */ | |
134 | static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors) | |
135 | { | |
136 | struct sd_dif_tuple *sdt = prot; | |
becce74b | 137 | u8 *tag = tag_buf; |
af55ff67 MP |
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 | ||
146 | static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors) | |
147 | { | |
148 | struct sd_dif_tuple *sdt = prot; | |
becce74b | 149 | u8 *tag = tag_buf; |
af55ff67 MP |
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 | ||
158 | static 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 | ||
168 | static 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 | */ | |
183 | static 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 | ||
198 | static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix) | |
199 | { | |
200 | sd_dif_type3_generate(bix, sd_dif_crc_fn); | |
201 | } | |
202 | ||
203 | static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix) | |
204 | { | |
205 | sd_dif_type3_generate(bix, sd_dif_ip_fn); | |
206 | } | |
207 | ||
208 | static 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 | ||
238 | static 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 | ||
243 | static 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 | ||
248 | static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors) | |
249 | { | |
250 | struct sd_dif_tuple *sdt = prot; | |
becce74b | 251 | u8 *tag = tag_buf; |
af55ff67 MP |
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 | ||
261 | static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors) | |
262 | { | |
263 | struct sd_dif_tuple *sdt = prot; | |
becce74b | 264 | u8 *tag = tag_buf; |
af55ff67 MP |
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 | ||
278 | static 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 | ||
288 | static 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 | */ | |
301 | void 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; | |
9e06688e | 306 | int dif, dix; |
af55ff67 | 307 | |
9e06688e MP |
308 | dif = scsi_host_dif_capable(sdp->host, type); |
309 | dix = scsi_host_dix_capable(sdp->host, type); | |
af55ff67 | 310 | |
9e06688e MP |
311 | if (!dix && scsi_host_dix_capable(sdp->host, 0)) { |
312 | dif = 0; dix = 1; | |
313 | } | |
af55ff67 | 314 | |
9e06688e | 315 | if (!dix) |
af55ff67 | 316 | return; |
af55ff67 MP |
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 | ||
cbdc1445 | 330 | sd_printk(KERN_NOTICE, sdkp, |
9e06688e | 331 | "Enabling DIX %s protection\n", disk->integrity->name); |
af55ff67 MP |
332 | |
333 | /* Signal to block layer that we support sector tagging */ | |
9e06688e | 334 | if (dif && type && sdkp->ATO) { |
af55ff67 MP |
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 | ||
cbdc1445 | 340 | sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n", |
af55ff67 MP |
341 | disk->integrity->tag_size); |
342 | } | |
343 | } | |
344 | ||
af55ff67 MP |
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 | */ | |
8c579ab6 MP |
361 | void sd_dif_prepare(struct request *rq, sector_t hw_sector, |
362 | unsigned int sector_sz) | |
af55ff67 MP |
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 | unsigned int i, j; | |
369 | u32 phys, virt; | |
370 | ||
af55ff67 MP |
371 | sdkp = rq->bio->bi_bdev->bd_disk->private_data; |
372 | ||
373 | if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION) | |
8c579ab6 | 374 | return; |
af55ff67 | 375 | |
af55ff67 MP |
376 | phys = hw_sector & 0xffffffff; |
377 | ||
378 | __rq_for_each_bio(bio, rq) { | |
379 | struct bio_vec *iv; | |
380 | ||
495d2b38 MP |
381 | /* Already remapped? */ |
382 | if (bio_flagged(bio, BIO_MAPPED_INTEGRITY)) | |
383 | break; | |
384 | ||
af55ff67 MP |
385 | virt = bio->bi_integrity->bip_sector & 0xffffffff; |
386 | ||
387 | bip_for_each_vec(iv, bio->bi_integrity, i) { | |
77dfce07 | 388 | sdt = kmap_atomic(iv->bv_page) |
af55ff67 MP |
389 | + iv->bv_offset; |
390 | ||
391 | for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) { | |
392 | ||
8c579ab6 MP |
393 | if (be32_to_cpu(sdt->ref_tag) == virt) |
394 | sdt->ref_tag = cpu_to_be32(phys); | |
af55ff67 | 395 | |
af55ff67 MP |
396 | virt++; |
397 | phys++; | |
398 | } | |
399 | ||
77dfce07 | 400 | kunmap_atomic(sdt); |
af55ff67 | 401 | } |
495d2b38 | 402 | |
9354f1b8 | 403 | bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY); |
af55ff67 | 404 | } |
af55ff67 MP |
405 | } |
406 | ||
407 | /* | |
408 | * Remap physical sector values in the reference tag to the virtual | |
409 | * values expected by the block layer. | |
410 | */ | |
411 | void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes) | |
412 | { | |
413 | const int tuple_sz = sizeof(struct sd_dif_tuple); | |
414 | struct scsi_disk *sdkp; | |
415 | struct bio *bio; | |
416 | struct sd_dif_tuple *sdt; | |
417 | unsigned int i, j, sectors, sector_sz; | |
418 | u32 phys, virt; | |
419 | ||
420 | sdkp = scsi_disk(scmd->request->rq_disk); | |
421 | ||
422 | if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0) | |
423 | return; | |
424 | ||
425 | sector_sz = scmd->device->sector_size; | |
426 | sectors = good_bytes / sector_sz; | |
427 | ||
83096ebf | 428 | phys = blk_rq_pos(scmd->request) & 0xffffffff; |
af55ff67 MP |
429 | if (sector_sz == 4096) |
430 | phys >>= 3; | |
431 | ||
432 | __rq_for_each_bio(bio, scmd->request) { | |
433 | struct bio_vec *iv; | |
434 | ||
435 | virt = bio->bi_integrity->bip_sector & 0xffffffff; | |
436 | ||
437 | bip_for_each_vec(iv, bio->bi_integrity, i) { | |
77dfce07 | 438 | sdt = kmap_atomic(iv->bv_page) |
af55ff67 MP |
439 | + iv->bv_offset; |
440 | ||
441 | for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) { | |
442 | ||
443 | if (sectors == 0) { | |
77dfce07 | 444 | kunmap_atomic(sdt); |
af55ff67 MP |
445 | return; |
446 | } | |
447 | ||
8c579ab6 | 448 | if (be32_to_cpu(sdt->ref_tag) == phys) |
af55ff67 MP |
449 | sdt->ref_tag = cpu_to_be32(virt); |
450 | ||
451 | virt++; | |
452 | phys++; | |
453 | sectors--; | |
454 | } | |
455 | ||
77dfce07 | 456 | kunmap_atomic(sdt); |
af55ff67 MP |
457 | } |
458 | } | |
459 | } | |
460 |