2 * sd_dif.c - SCSI Data Integrity Field
4 * Copyright (C) 2007, 2008 Oracle Corporation
5 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
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.
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.
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,
23 #include <linux/blkdev.h>
24 #include <linux/crc-t10dif.h>
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>
36 #include <net/checksum.h>
40 typedef __u16 (csum_fn
) (void *, unsigned int);
42 static __u16
sd_dif_crc_fn(void *data
, unsigned int len
)
44 return cpu_to_be16(crc_t10dif(data
, len
));
47 static __u16
sd_dif_ip_fn(void *data
, unsigned int len
)
49 return ip_compute_csum(data
, len
);
53 * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
54 * 16 bit app tag, 32 bit reference tag.
56 static void sd_dif_type1_generate(struct blk_integrity_exchg
*bix
, csum_fn
*fn
)
58 void *buf
= bix
->data_buf
;
59 struct sd_dif_tuple
*sdt
= bix
->prot_buf
;
60 sector_t sector
= bix
->sector
;
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);
68 buf
+= bix
->sector_size
;
73 static void sd_dif_type1_generate_crc(struct blk_integrity_exchg
*bix
)
75 sd_dif_type1_generate(bix
, sd_dif_crc_fn
);
78 static void sd_dif_type1_generate_ip(struct blk_integrity_exchg
*bix
)
80 sd_dif_type1_generate(bix
, sd_dif_ip_fn
);
83 static int sd_dif_type1_verify(struct blk_integrity_exchg
*bix
, csum_fn
*fn
)
85 void *buf
= bix
->data_buf
;
86 struct sd_dif_tuple
*sdt
= bix
->prot_buf
;
87 sector_t sector
= bix
->sector
;
91 for (i
= 0 ; i
< bix
->data_size
; i
+= bix
->sector_size
, sdt
++) {
92 /* Unwritten sectors */
93 if (sdt
->app_tag
== 0xffff)
96 /* Bad ref tag received from disk */
97 if (sdt
->ref_tag
== 0xffffffff) {
99 "%s: bad phys ref tag on sector %lu\n",
100 bix
->disk_name
, (unsigned long)sector
);
104 if (be32_to_cpu(sdt
->ref_tag
) != (sector
& 0xffffffff)) {
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
));
112 csum
= fn(buf
, bix
->sector_size
);
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
));
122 buf
+= bix
->sector_size
;
129 static int sd_dif_type1_verify_crc(struct blk_integrity_exchg
*bix
)
131 return sd_dif_type1_verify(bix
, sd_dif_crc_fn
);
134 static int sd_dif_type1_verify_ip(struct blk_integrity_exchg
*bix
)
136 return sd_dif_type1_verify(bix
, sd_dif_ip_fn
);
140 * Functions for interleaving and deinterleaving application tags
142 static void sd_dif_type1_set_tag(void *prot
, void *tag_buf
, unsigned int sectors
)
144 struct sd_dif_tuple
*sdt
= prot
;
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);
154 static void sd_dif_type1_get_tag(void *prot
, void *tag_buf
, unsigned int sectors
)
156 struct sd_dif_tuple
*sdt
= prot
;
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;
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
),
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
),
188 * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
191 static void sd_dif_type3_generate(struct blk_integrity_exchg
*bix
, csum_fn
*fn
)
193 void *buf
= bix
->data_buf
;
194 struct sd_dif_tuple
*sdt
= bix
->prot_buf
;
197 for (i
= 0 ; i
< bix
->data_size
; i
+= bix
->sector_size
, sdt
++) {
198 sdt
->guard_tag
= fn(buf
, bix
->sector_size
);
202 buf
+= bix
->sector_size
;
206 static void sd_dif_type3_generate_crc(struct blk_integrity_exchg
*bix
)
208 sd_dif_type3_generate(bix
, sd_dif_crc_fn
);
211 static void sd_dif_type3_generate_ip(struct blk_integrity_exchg
*bix
)
213 sd_dif_type3_generate(bix
, sd_dif_ip_fn
);
216 static int sd_dif_type3_verify(struct blk_integrity_exchg
*bix
, csum_fn
*fn
)
218 void *buf
= bix
->data_buf
;
219 struct sd_dif_tuple
*sdt
= bix
->prot_buf
;
220 sector_t sector
= bix
->sector
;
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)
229 csum
= fn(buf
, bix
->sector_size
);
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
));
239 buf
+= bix
->sector_size
;
246 static int sd_dif_type3_verify_crc(struct blk_integrity_exchg
*bix
)
248 return sd_dif_type3_verify(bix
, sd_dif_crc_fn
);
251 static int sd_dif_type3_verify_ip(struct blk_integrity_exchg
*bix
)
253 return sd_dif_type3_verify(bix
, sd_dif_ip_fn
);
256 static void sd_dif_type3_set_tag(void *prot
, void *tag_buf
, unsigned int sectors
)
258 struct sd_dif_tuple
*sdt
= prot
;
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];
269 static void sd_dif_type3_get_tag(void *prot
, void *tag_buf
, unsigned int sectors
)
271 struct sd_dif_tuple
*sdt
= prot
;
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);
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
),
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
),
307 * Configure exchange of protection information between OS and HBA.
309 void sd_dif_config_host(struct scsi_disk
*sdkp
)
311 struct scsi_device
*sdp
= sdkp
->device
;
312 struct gendisk
*disk
= sdkp
->disk
;
313 u8 type
= sdkp
->protection_type
;
316 dif
= scsi_host_dif_capable(sdp
->host
, type
);
317 dix
= scsi_host_dix_capable(sdp
->host
, type
);
319 if (!dix
&& scsi_host_dix_capable(sdp
->host
, 0)) {
326 /* Enable DMA of protection information */
327 if (scsi_host_get_guard(sdkp
->device
->host
) & SHOST_DIX_GUARD_IP
)
328 if (type
== SD_DIF_TYPE3_PROTECTION
)
329 blk_integrity_register(disk
, &dif_type3_integrity_ip
);
331 blk_integrity_register(disk
, &dif_type1_integrity_ip
);
333 if (type
== SD_DIF_TYPE3_PROTECTION
)
334 blk_integrity_register(disk
, &dif_type3_integrity_crc
);
336 blk_integrity_register(disk
, &dif_type1_integrity_crc
);
338 sd_printk(KERN_NOTICE
, sdkp
,
339 "Enabling DIX %s protection\n", disk
->integrity
->name
);
341 /* Signal to block layer that we support sector tagging */
342 if (dif
&& type
&& sdkp
->ATO
) {
343 if (type
== SD_DIF_TYPE3_PROTECTION
)
344 disk
->integrity
->tag_size
= sizeof(u16
) + sizeof(u32
);
346 disk
->integrity
->tag_size
= sizeof(u16
);
348 sd_printk(KERN_NOTICE
, sdkp
, "DIF application tag size %u\n",
349 disk
->integrity
->tag_size
);
354 * The virtual start sector is the one that was originally submitted
355 * by the block layer. Due to partitioning, MD/DM cloning, etc. the
356 * actual physical start sector is likely to be different. Remap
357 * protection information to match the physical LBA.
359 * From a protocol perspective there's a slight difference between
360 * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the
361 * reference tag is seeded in the CDB. This gives us the potential to
362 * avoid virt->phys remapping during write. However, at read time we
363 * don't know whether the virt sector is the same as when we wrote it
364 * (we could be reading from real disk as opposed to MD/DM device. So
365 * we always remap Type 2 making it identical to Type 1.
367 * Type 3 does not have a reference tag so no remapping is required.
369 int sd_dif_prepare(struct request
*rq
, sector_t hw_sector
, unsigned int sector_sz
)
371 const int tuple_sz
= sizeof(struct sd_dif_tuple
);
373 struct scsi_disk
*sdkp
;
374 struct sd_dif_tuple
*sdt
;
378 sdkp
= rq
->bio
->bi_bdev
->bd_disk
->private_data
;
380 if (sdkp
->protection_type
== SD_DIF_TYPE3_PROTECTION
)
383 phys
= hw_sector
& 0xffffffff;
385 __rq_for_each_bio(bio
, rq
) {
388 /* Already remapped? */
389 if (bio_flagged(bio
, BIO_MAPPED_INTEGRITY
))
392 virt
= bio
->bi_integrity
->bip_sector
& 0xffffffff;
394 bip_for_each_vec(iv
, bio
->bi_integrity
, i
) {
395 sdt
= kmap_atomic(iv
->bv_page
)
398 for (j
= 0 ; j
< iv
->bv_len
; j
+= tuple_sz
, sdt
++) {
400 if (be32_to_cpu(sdt
->ref_tag
) != virt
)
403 sdt
->ref_tag
= cpu_to_be32(phys
);
411 bio
->bi_flags
|= (1 << BIO_MAPPED_INTEGRITY
);
418 sd_printk(KERN_ERR
, sdkp
, "%s: virt %u, phys %u, ref %u, app %4x\n",
419 __func__
, virt
, phys
, be32_to_cpu(sdt
->ref_tag
),
420 be16_to_cpu(sdt
->app_tag
));
426 * Remap physical sector values in the reference tag to the virtual
427 * values expected by the block layer.
429 void sd_dif_complete(struct scsi_cmnd
*scmd
, unsigned int good_bytes
)
431 const int tuple_sz
= sizeof(struct sd_dif_tuple
);
432 struct scsi_disk
*sdkp
;
434 struct sd_dif_tuple
*sdt
;
435 unsigned int i
, j
, sectors
, sector_sz
;
438 sdkp
= scsi_disk(scmd
->request
->rq_disk
);
440 if (sdkp
->protection_type
== SD_DIF_TYPE3_PROTECTION
|| good_bytes
== 0)
443 sector_sz
= scmd
->device
->sector_size
;
444 sectors
= good_bytes
/ sector_sz
;
446 phys
= blk_rq_pos(scmd
->request
) & 0xffffffff;
447 if (sector_sz
== 4096)
450 __rq_for_each_bio(bio
, scmd
->request
) {
453 virt
= bio
->bi_integrity
->bip_sector
& 0xffffffff;
455 bip_for_each_vec(iv
, bio
->bi_integrity
, i
) {
456 sdt
= kmap_atomic(iv
->bv_page
)
459 for (j
= 0 ; j
< iv
->bv_len
; j
+= tuple_sz
, sdt
++) {
466 if (be32_to_cpu(sdt
->ref_tag
) != phys
&&
467 sdt
->app_tag
!= 0xffff)
468 sdt
->ref_tag
= 0xffffffff; /* Bad ref */
470 sdt
->ref_tag
= cpu_to_be32(virt
);