summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/sd_dif.c
blob: a7a691d0af7d105a431ba3b560a5496acb71d58b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
/*
 * sd_dif.c - SCSI Data Integrity Field
 *
 * Copyright (C) 2007, 2008 Oracle Corporation
 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 * USA.
 *
 */

#include <linux/blkdev.h>
#include <linux/crc-t10dif.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsicam.h>

#include <net/checksum.h>

#include "sd.h"

typedef __u16 (csum_fn) (void *, unsigned int);

static __u16 sd_dif_crc_fn(void *data, unsigned int len)
{
	return cpu_to_be16(crc_t10dif(data, len));
}

static __u16 sd_dif_ip_fn(void *data, unsigned int len)
{
	return ip_compute_csum(data, len);
}

/*
 * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
 * 16 bit app tag, 32 bit reference tag.
 */
static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
{
	void *buf = bix->data_buf;
	struct sd_dif_tuple *sdt = bix->prot_buf;
	sector_t sector = bix->sector;
	unsigned int i;

	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
		sdt->guard_tag = fn(buf, bix->sector_size);
		sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
		sdt->app_tag = 0;

		buf += bix->sector_size;
		sector++;
	}
}

static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix)
{
	sd_dif_type1_generate(bix, sd_dif_crc_fn);
}

static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix)
{
	sd_dif_type1_generate(bix, sd_dif_ip_fn);
}

static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
{
	void *buf = bix->data_buf;
	struct sd_dif_tuple *sdt = bix->prot_buf;
	sector_t sector = bix->sector;
	unsigned int i;
	__u16 csum;

	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
		/* Unwritten sectors */
		if (sdt->app_tag == 0xffff)
			return 0;

		if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
			printk(KERN_ERR
			       "%s: ref tag error on sector %lu (rcvd %u)\n",
			       bix->disk_name, (unsigned long)sector,
			       be32_to_cpu(sdt->ref_tag));
			return -EIO;
		}

		csum = fn(buf, bix->sector_size);

		if (sdt->guard_tag != csum) {
			printk(KERN_ERR "%s: guard tag error on sector %lu " \
			       "(rcvd %04x, data %04x)\n", bix->disk_name,
			       (unsigned long)sector,
			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
			return -EIO;
		}

		buf += bix->sector_size;
		sector++;
	}

	return 0;
}

static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix)
{
	return sd_dif_type1_verify(bix, sd_dif_crc_fn);
}

static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix)
{
	return sd_dif_type1_verify(bix, sd_dif_ip_fn);
}

/*
 * Functions for interleaving and deinterleaving application tags
 */
static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors)
{
	struct sd_dif_tuple *sdt = prot;
	u8 *tag = tag_buf;
	unsigned int i, j;

	for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
		sdt->app_tag = tag[j] << 8 | tag[j+1];
		BUG_ON(sdt->app_tag == 0xffff);
	}
}

static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors)
{
	struct sd_dif_tuple *sdt = prot;
	u8 *tag = tag_buf;
	unsigned int i, j;

	for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
		tag[j] = (sdt->app_tag & 0xff00) >> 8;
		tag[j+1] = sdt->app_tag & 0xff;
	}
}

static struct blk_integrity dif_type1_integrity_crc = {
	.name			= "T10-DIF-TYPE1-CRC",
	.generate_fn		= sd_dif_type1_generate_crc,
	.verify_fn		= sd_dif_type1_verify_crc,
	.get_tag_fn		= sd_dif_type1_get_tag,
	.set_tag_fn		= sd_dif_type1_set_tag,
	.tuple_size		= sizeof(struct sd_dif_tuple),
	.tag_size		= 0,
};

static struct blk_integrity dif_type1_integrity_ip = {
	.name			= "T10-DIF-TYPE1-IP",
	.generate_fn		= sd_dif_type1_generate_ip,
	.verify_fn		= sd_dif_type1_verify_ip,
	.get_tag_fn		= sd_dif_type1_get_tag,
	.set_tag_fn		= sd_dif_type1_set_tag,
	.tuple_size		= sizeof(struct sd_dif_tuple),
	.tag_size		= 0,
};


/*
 * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque
 * tag space.
 */
static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn)
{
	void *buf = bix->data_buf;
	struct sd_dif_tuple *sdt = bix->prot_buf;
	unsigned int i;

	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
		sdt->guard_tag = fn(buf, bix->sector_size);
		sdt->ref_tag = 0;
		sdt->app_tag = 0;

		buf += bix->sector_size;
	}
}

static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix)
{
	sd_dif_type3_generate(bix, sd_dif_crc_fn);
}

static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix)
{
	sd_dif_type3_generate(bix, sd_dif_ip_fn);
}

static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn)
{
	void *buf = bix->data_buf;
	struct sd_dif_tuple *sdt = bix->prot_buf;
	sector_t sector = bix->sector;
	unsigned int i;
	__u16 csum;

	for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) {
		/* Unwritten sectors */
		if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)
			return 0;

		csum = fn(buf, bix->sector_size);

		if (sdt->guard_tag != csum) {
			printk(KERN_ERR "%s: guard tag error on sector %lu " \
			       "(rcvd %04x, data %04x)\n", bix->disk_name,
			       (unsigned long)sector,
			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
			return -EIO;
		}

		buf += bix->sector_size;
		sector++;
	}

	return 0;
}

static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix)
{
	return sd_dif_type3_verify(bix, sd_dif_crc_fn);
}

static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix)
{
	return sd_dif_type3_verify(bix, sd_dif_ip_fn);
}

static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors)
{
	struct sd_dif_tuple *sdt = prot;
	u8 *tag = tag_buf;
	unsigned int i, j;

	for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) {
		sdt->app_tag = tag[j] << 8 | tag[j+1];
		sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 |
			tag[j+4] << 8 | tag[j+5];
	}
}

static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors)
{
	struct sd_dif_tuple *sdt = prot;
	u8 *tag = tag_buf;
	unsigned int i, j;

	for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) {
		tag[j] = (sdt->app_tag & 0xff00) >> 8;
		tag[j+1] = sdt->app_tag & 0xff;
		tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24;
		tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16;
		tag[j+4] = (sdt->ref_tag & 0xff00) >> 8;
		tag[j+5] = sdt->ref_tag & 0xff;
		BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff);
	}
}

static struct blk_integrity dif_type3_integrity_crc = {
	.name			= "T10-DIF-TYPE3-CRC",
	.generate_fn		= sd_dif_type3_generate_crc,
	.verify_fn		= sd_dif_type3_verify_crc,
	.get_tag_fn		= sd_dif_type3_get_tag,
	.set_tag_fn		= sd_dif_type3_set_tag,
	.tuple_size		= sizeof(struct sd_dif_tuple),
	.tag_size		= 0,
};

static struct blk_integrity dif_type3_integrity_ip = {
	.name			= "T10-DIF-TYPE3-IP",
	.generate_fn		= sd_dif_type3_generate_ip,
	.verify_fn		= sd_dif_type3_verify_ip,
	.get_tag_fn		= sd_dif_type3_get_tag,
	.set_tag_fn		= sd_dif_type3_set_tag,
	.tuple_size		= sizeof(struct sd_dif_tuple),
	.tag_size		= 0,
};

/*
 * Configure exchange of protection information between OS and HBA.
 */
void sd_dif_config_host(struct scsi_disk *sdkp)
{
	struct scsi_device *sdp = sdkp->device;
	struct gendisk *disk = sdkp->disk;
	u8 type = sdkp->protection_type;
	int dif, dix;

	dif = scsi_host_dif_capable(sdp->host, type);
	dix = scsi_host_dix_capable(sdp->host, type);

	if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
		dif = 0; dix = 1;
	}

	if (!dix)
		return;

	/* Enable DMA of protection information */
	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP)
		if (type == SD_DIF_TYPE3_PROTECTION)
			blk_integrity_register(disk, &dif_type3_integrity_ip);
		else
			blk_integrity_register(disk, &dif_type1_integrity_ip);
	else
		if (type == SD_DIF_TYPE3_PROTECTION)
			blk_integrity_register(disk, &dif_type3_integrity_crc);
		else
			blk_integrity_register(disk, &dif_type1_integrity_crc);

	sd_printk(KERN_NOTICE, sdkp,
		  "Enabling DIX %s protection\n", disk->integrity->name);

	/* Signal to block layer that we support sector tagging */
	if (dif && type && sdkp->ATO) {
		if (type == SD_DIF_TYPE3_PROTECTION)
			disk->integrity->tag_size = sizeof(u16) + sizeof(u32);
		else
			disk->integrity->tag_size = sizeof(u16);

		sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
			  disk->integrity->tag_size);
	}
}

/*
 * The virtual start sector is the one that was originally submitted
 * by the block layer.	Due to partitioning, MD/DM cloning, etc. the
 * actual physical start sector is likely to be different.  Remap
 * protection information to match the physical LBA.
 *
 * From a protocol perspective there's a slight difference between
 * Type 1 and 2.  The latter uses 32-byte CDBs exclusively, and the
 * reference tag is seeded in the CDB.  This gives us the potential to
 * avoid virt->phys remapping during write.  However, at read time we
 * don't know whether the virt sector is the same as when we wrote it
 * (we could be reading from real disk as opposed to MD/DM device.  So
 * we always remap Type 2 making it identical to Type 1.
 *
 * Type 3 does not have a reference tag so no remapping is required.
 */
void sd_dif_prepare(struct request *rq, sector_t hw_sector,
		    unsigned int sector_sz)
{
	const int tuple_sz = sizeof(struct sd_dif_tuple);
	struct bio *bio;
	struct scsi_disk *sdkp;
	struct sd_dif_tuple *sdt;
	u32 phys, virt;

	sdkp = rq->bio->bi_bdev->bd_disk->private_data;

	if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION)
		return;

	phys = hw_sector & 0xffffffff;

	__rq_for_each_bio(bio, rq) {
		struct bio_vec iv;
		struct bvec_iter iter;
		unsigned int j;

		/* Already remapped? */
		if (bio_flagged(bio, BIO_MAPPED_INTEGRITY))
			break;

		virt = bio->bi_integrity->bip_iter.bi_sector & 0xffffffff;

		bip_for_each_vec(iv, bio->bi_integrity, iter) {
			sdt = kmap_atomic(iv.bv_page)
				+ iv.bv_offset;

			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {

				if (be32_to_cpu(sdt->ref_tag) == virt)
					sdt->ref_tag = cpu_to_be32(phys);

				virt++;
				phys++;
			}

			kunmap_atomic(sdt);
		}

		bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY);
	}
}

/*
 * Remap physical sector values in the reference tag to the virtual
 * values expected by the block layer.
 */
void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)
{
	const int tuple_sz = sizeof(struct sd_dif_tuple);
	struct scsi_disk *sdkp;
	struct bio *bio;
	struct sd_dif_tuple *sdt;
	unsigned int j, sectors, sector_sz;
	u32 phys, virt;

	sdkp = scsi_disk(scmd->request->rq_disk);

	if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0)
		return;

	sector_sz = scmd->device->sector_size;
	sectors = good_bytes / sector_sz;

	phys = blk_rq_pos(scmd->request) & 0xffffffff;
	if (sector_sz == 4096)
		phys >>= 3;

	__rq_for_each_bio(bio, scmd->request) {
		struct bio_vec iv;
		struct bvec_iter iter;

		virt = bio->bi_integrity->bip_iter.bi_sector & 0xffffffff;

		bip_for_each_vec(iv, bio->bi_integrity, iter) {
			sdt = kmap_atomic(iv.bv_page)
				+ iv.bv_offset;

			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {

				if (sectors == 0) {
					kunmap_atomic(sdt);
					return;
				}

				if (be32_to_cpu(sdt->ref_tag) == phys)
					sdt->ref_tag = cpu_to_be32(virt);

				virt++;
				phys++;
				sectors--;
			}

			kunmap_atomic(sdt);
		}
	}
}

OpenPOWER on IntegriCloud