config: tegra3: enable /dev mount with ACL
[linux-2.6.git] / drivers / scsi / sd_dif.c
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         u8 *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         u8 *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         u8 *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         u8 *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;
314         int dif, dix;
315
316         dif = scsi_host_dif_capable(sdp->host, type);
317         dix = scsi_host_dix_capable(sdp->host, type);
318
319         if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
320                 dif = 0; dix = 1;
321         }
322
323         if (!dix)
324                 return;
325
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);
330                 else
331                         blk_integrity_register(disk, &dif_type1_integrity_ip);
332         else
333                 if (type == SD_DIF_TYPE3_PROTECTION)
334                         blk_integrity_register(disk, &dif_type3_integrity_crc);
335                 else
336                         blk_integrity_register(disk, &dif_type1_integrity_crc);
337
338         sd_printk(KERN_NOTICE, sdkp,
339                   "Enabling DIX %s protection\n", disk->integrity->name);
340
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);
345                 else
346                         disk->integrity->tag_size = sizeof(u16);
347
348                 sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
349                           disk->integrity->tag_size);
350         }
351 }
352
353 /*
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.
358  *
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.
366  *
367  * Type 3 does not have a reference tag so no remapping is required.
368  */
369 int sd_dif_prepare(struct request *rq, sector_t hw_sector, unsigned int sector_sz)
370 {
371         const int tuple_sz = sizeof(struct sd_dif_tuple);
372         struct bio *bio;
373         struct scsi_disk *sdkp;
374         struct sd_dif_tuple *sdt;
375         unsigned int i, j;
376         u32 phys, virt;
377
378         sdkp = rq->bio->bi_bdev->bd_disk->private_data;
379
380         if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
381                 return 0;
382
383         phys = hw_sector & 0xffffffff;
384
385         __rq_for_each_bio(bio, rq) {
386                 struct bio_vec *iv;
387
388                 /* Already remapped? */
389                 if (bio_flagged(bio, BIO_MAPPED_INTEGRITY))
390                         break;
391
392                 virt = bio->bi_integrity->bip_sector & 0xffffffff;
393
394                 bip_for_each_vec(iv, bio->bi_integrity, i) {
395                         sdt = kmap_atomic(iv->bv_page, KM_USER0)
396                                 + iv->bv_offset;
397
398                         for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
399
400                                 if (be32_to_cpu(sdt->ref_tag) != virt)
401                                         goto error;
402
403                                 sdt->ref_tag = cpu_to_be32(phys);
404                                 virt++;
405                                 phys++;
406                         }
407
408                         kunmap_atomic(sdt, KM_USER0);
409                 }
410
411                 bio->bi_flags |= BIO_MAPPED_INTEGRITY;
412         }
413
414         return 0;
415
416 error:
417         kunmap_atomic(sdt, KM_USER0);
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));
421
422         return -EILSEQ;
423 }
424
425 /*
426  * Remap physical sector values in the reference tag to the virtual
427  * values expected by the block layer.
428  */
429 void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
430 {
431         const int tuple_sz = sizeof(struct sd_dif_tuple);
432         struct scsi_disk *sdkp;
433         struct bio *bio;
434         struct sd_dif_tuple *sdt;
435         unsigned int i, j, sectors, sector_sz;
436         u32 phys, virt;
437
438         sdkp = scsi_disk(scmd->request->rq_disk);
439
440         if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
441                 return;
442
443         sector_sz = scmd->device->sector_size;
444         sectors = good_bytes / sector_sz;
445
446         phys = blk_rq_pos(scmd->request) & 0xffffffff;
447         if (sector_sz == 4096)
448                 phys >>= 3;
449
450         __rq_for_each_bio(bio, scmd->request) {
451                 struct bio_vec *iv;
452
453                 virt = bio->bi_integrity->bip_sector & 0xffffffff;
454
455                 bip_for_each_vec(iv, bio->bi_integrity, i) {
456                         sdt = kmap_atomic(iv->bv_page, KM_USER0)
457                                 + iv->bv_offset;
458
459                         for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) {
460
461                                 if (sectors == 0) {
462                                         kunmap_atomic(sdt, KM_USER0);
463                                         return;
464                                 }
465
466                                 if (be32_to_cpu(sdt->ref_tag) != phys &&
467                                     sdt->app_tag != 0xffff)
468                                         sdt->ref_tag = 0xffffffff; /* Bad ref */
469                                 else
470                                         sdt->ref_tag = cpu_to_be32(virt);
471
472                                 virt++;
473                                 phys++;
474                                 sectors--;
475                         }
476
477                         kunmap_atomic(sdt, KM_USER0);
478                 }
479         }
480 }
481