summaryrefslogtreecommitdiffstats
path: root/drivers/s390/block/dasd_diag.c
blob: 6bb775236c1677952af355e97f729afda83d95f5 (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
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
// SPDX-License-Identifier: GPL-2.0
/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 * Based on.......: linux/drivers/s390/block/mdisk.c
 * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999, 2000
 *
 */

#define KMSG_COMPONENT "dasd"

#include <linux/kernel_stat.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/hdreg.h>
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/jiffies.h>

#include <asm/dasd.h>
#include <asm/debug.h>
#include <asm/diag.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/vtoc.h>

#include "dasd_int.h"
#include "dasd_diag.h"

#define PRINTK_HEADER "dasd(diag):"

MODULE_LICENSE("GPL");

/* The maximum number of blocks per request (max_blocks) is dependent on the
 * amount of storage that is available in the static I/O buffer for each
 * device. Currently each device gets 2 pages. We want to fit two requests
 * into the available memory so that we can immediately start the next if one
 * finishes. */
#define DIAG_MAX_BLOCKS	(((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
			   sizeof(struct dasd_diag_req)) / \
		           sizeof(struct dasd_diag_bio)) / 2)
#define DIAG_MAX_RETRIES	32
#define DIAG_TIMEOUT		50

static struct dasd_discipline dasd_diag_discipline;

struct dasd_diag_private {
	struct dasd_diag_characteristics rdc_data;
	struct dasd_diag_rw_io iob;
	struct dasd_diag_init_io iib;
	blocknum_t pt_block;
	struct ccw_dev_id dev_id;
};

struct dasd_diag_req {
	unsigned int block_count;
	struct dasd_diag_bio bio[];
};

static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */

/* Perform DIAG250 call with block I/O parameter list iob (input and output)
 * and function code cmd.
 * In case of an exception return 3. Otherwise return result of bitwise OR of
 * resulting condition code and DIAG return code. */
static inline int __dia250(void *iob, int cmd)
{
	union register_pair rx = { .even = (unsigned long)iob, };
	typedef union {
		struct dasd_diag_init_io init_io;
		struct dasd_diag_rw_io rw_io;
	} addr_type;
	int cc;

	cc = 3;
	asm volatile(
		"	diag	%[rx],%[cmd],0x250\n"
		"0:	ipm	%[cc]\n"
		"	srl	%[cc],28\n"
		"1:\n"
		EX_TABLE(0b,1b)
		: [cc] "+&d" (cc), [rx] "+&d" (rx.pair), "+m" (*(addr_type *)iob)
		: [cmd] "d" (cmd)
		: "cc");
	return cc | rx.odd;
}

static inline int dia250(void *iob, int cmd)
{
	diag_stat_inc(DIAG_STAT_X250);
	return __dia250(iob, cmd);
}

/* Initialize block I/O to DIAG device using the specified blocksize and
 * block offset. On success, return zero and set end_block to contain the
 * number of blocks on the device minus the specified offset. Return non-zero
 * otherwise. */
static inline int
mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
	     blocknum_t offset, blocknum_t *end_block)
{
	struct dasd_diag_private *private = device->private;
	struct dasd_diag_init_io *iib = &private->iib;
	int rc;

	memset(iib, 0, sizeof (struct dasd_diag_init_io));

	iib->dev_nr = private->dev_id.devno;
	iib->block_size = blocksize;
	iib->offset = offset;
	iib->flaga = DASD_DIAG_FLAGA_DEFAULT;

	rc = dia250(iib, INIT_BIO);

	if ((rc & 3) == 0 && end_block)
		*end_block = iib->end_block;

	return rc;
}

/* Remove block I/O environment for device. Return zero on success, non-zero
 * otherwise. */
static inline int
mdsk_term_io(struct dasd_device * device)
{
	struct dasd_diag_private *private = device->private;
	struct dasd_diag_init_io *iib = &private->iib;
	int rc;

	memset(iib, 0, sizeof (struct dasd_diag_init_io));
	iib->dev_nr = private->dev_id.devno;
	rc = dia250(iib, TERM_BIO);
	return rc;
}

/* Error recovery for failed DIAG requests - try to reestablish the DIAG
 * environment. */
static void
dasd_diag_erp(struct dasd_device *device)
{
	int rc;

	mdsk_term_io(device);
	rc = mdsk_init_io(device, device->block->bp_block, 0, NULL);
	if (rc == 4) {
		if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags)))
			pr_warn("%s: The access mode of a DIAG device changed to read-only\n",
				dev_name(&device->cdev->dev));
		rc = 0;
	}
	if (rc)
		pr_warn("%s: DIAG ERP failed with rc=%d\n",
			dev_name(&device->cdev->dev), rc);
}

/* Start a given request at the device. Return zero on success, non-zero
 * otherwise. */
static int
dasd_start_diag(struct dasd_ccw_req * cqr)
{
	struct dasd_device *device;
	struct dasd_diag_private *private;
	struct dasd_diag_req *dreq;
	int rc;

	device = cqr->startdev;
	if (cqr->retries < 0) {
		DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
			    "- no retry left)", cqr);
		cqr->status = DASD_CQR_ERROR;
		return -EIO;
	}
	private = device->private;
	dreq = cqr->data;

	private->iob.dev_nr = private->dev_id.devno;
	private->iob.key = 0;
	private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
	private->iob.block_count = dreq->block_count;
	private->iob.interrupt_params = (addr_t) cqr;
	private->iob.bio_list = dreq->bio;
	private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;

	cqr->startclk = get_tod_clock();
	cqr->starttime = jiffies;
	cqr->retries--;

	rc = dia250(&private->iob, RW_BIO);
	switch (rc) {
	case 0: /* Synchronous I/O finished successfully */
		cqr->stopclk = get_tod_clock();
		cqr->status = DASD_CQR_SUCCESS;
		/* Indicate to calling function that only a dasd_schedule_bh()
		   and no timer is needed */
                rc = -EACCES;
		break;
	case 8: /* Asynchronous I/O was started */
		cqr->status = DASD_CQR_IN_IO;
		rc = 0;
		break;
	default: /* Error condition */
		cqr->status = DASD_CQR_QUEUED;
		DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
		dasd_diag_erp(device);
		rc = -EIO;
		break;
	}
	cqr->intrc = rc;
	return rc;
}

/* Terminate given request at the device. */
static int
dasd_diag_term_IO(struct dasd_ccw_req * cqr)
{
	struct dasd_device *device;

	device = cqr->startdev;
	mdsk_term_io(device);
	mdsk_init_io(device, device->block->bp_block, 0, NULL);
	cqr->status = DASD_CQR_CLEAR_PENDING;
	cqr->stopclk = get_tod_clock();
	dasd_schedule_device_bh(device);
	return 0;
}

/* Handle external interruption. */
static void dasd_ext_handler(struct ext_code ext_code,
			     unsigned int param32, unsigned long param64)
{
	struct dasd_ccw_req *cqr, *next;
	struct dasd_device *device;
	unsigned long expires;
	unsigned long flags;
	addr_t ip;
	int rc;

	switch (ext_code.subcode >> 8) {
	case DASD_DIAG_CODE_31BIT:
		ip = (addr_t) param32;
		break;
	case DASD_DIAG_CODE_64BIT:
		ip = (addr_t) param64;
		break;
	default:
		return;
	}
	inc_irq_stat(IRQEXT_DSD);
	if (!ip) {		/* no intparm: unsolicited interrupt */
		DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
			      "interrupt");
		return;
	}
	cqr = (struct dasd_ccw_req *) ip;
	device = (struct dasd_device *) cqr->startdev;
	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
		DBF_DEV_EVENT(DBF_WARNING, device,
			    " magic number of dasd_ccw_req 0x%08X doesn't"
			    " match discipline 0x%08X",
			    cqr->magic, *(int *) (&device->discipline->name));
		return;
	}

	/* get irq lock to modify request queue */
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);

	/* Check for a pending clear operation */
	if (cqr->status == DASD_CQR_CLEAR_PENDING) {
		cqr->status = DASD_CQR_CLEARED;
		dasd_device_clear_timer(device);
		dasd_schedule_device_bh(device);
		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
		return;
	}

	cqr->stopclk = get_tod_clock();

	expires = 0;
	if ((ext_code.subcode & 0xff) == 0) {
		cqr->status = DASD_CQR_SUCCESS;
		/* Start first request on queue if possible -> fast_io. */
		if (!list_empty(&device->ccw_queue)) {
			next = list_entry(device->ccw_queue.next,
					  struct dasd_ccw_req, devlist);
			if (next->status == DASD_CQR_QUEUED) {
				rc = dasd_start_diag(next);
				if (rc == 0)
					expires = next->expires;
			}
		}
	} else {
		cqr->status = DASD_CQR_QUEUED;
		DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
			      "request %p was %d (%d retries left)", cqr,
			      ext_code.subcode & 0xff, cqr->retries);
		dasd_diag_erp(device);
	}

	if (expires != 0)
		dasd_device_set_timer(device, expires);
	else
		dasd_device_clear_timer(device);
	dasd_schedule_device_bh(device);

	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}

/* Check whether device can be controlled by DIAG discipline. Return zero on
 * success, non-zero otherwise. */
static int
dasd_diag_check_device(struct dasd_device *device)
{
	struct dasd_diag_private *private = device->private;
	struct dasd_diag_characteristics *rdc_data;
	struct vtoc_cms_label *label;
	struct dasd_block *block;
	struct dasd_diag_bio *bio;
	unsigned int sb, bsize;
	blocknum_t end_block;
	int rc;

	if (private == NULL) {
		private = kzalloc(sizeof(*private), GFP_KERNEL);
		if (private == NULL) {
			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
				"Allocating memory for private DASD data "
				      "failed\n");
			return -ENOMEM;
		}
		ccw_device_get_id(device->cdev, &private->dev_id);
		device->private = private;
	}
	block = dasd_alloc_block();
	if (IS_ERR(block)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			    "could not allocate dasd block structure");
		device->private = NULL;
		kfree(private);
		return PTR_ERR(block);
	}
	device->block = block;
	block->base = device;

	/* Read Device Characteristics */
	rdc_data = &private->rdc_data;
	rdc_data->dev_nr = private->dev_id.devno;
	rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);

	rc = diag210((struct diag210 *) rdc_data);
	if (rc) {
		DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device "
			    "information (rc=%d)", rc);
		rc = -EOPNOTSUPP;
		goto out;
	}

	device->default_expires = DIAG_TIMEOUT;
	device->default_retries = DIAG_MAX_RETRIES;

	/* Figure out position of label block */
	switch (private->rdc_data.vdev_class) {
	case DEV_CLASS_FBA:
		private->pt_block = 1;
		break;
	case DEV_CLASS_ECKD:
		private->pt_block = 2;
		break;
	default:
		pr_warn("%s: Device type %d is not supported in DIAG mode\n",
			dev_name(&device->cdev->dev),
			private->rdc_data.vdev_class);
		rc = -EOPNOTSUPP;
		goto out;
	}

	DBF_DEV_EVENT(DBF_INFO, device,
		      "%04X: %04X on real %04X/%02X",
		      rdc_data->dev_nr,
		      rdc_data->vdev_type,
		      rdc_data->rdev_type, rdc_data->rdev_model);

	/* terminate all outstanding operations */
	mdsk_term_io(device);

	/* figure out blocksize of device */
	label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
	if (label == NULL)  {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			    "No memory to allocate initialization request");
		rc = -ENOMEM;
		goto out;
	}
	bio = kzalloc(sizeof(*bio), GFP_KERNEL);
	if (bio == NULL)  {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "No memory to allocate initialization bio");
		rc = -ENOMEM;
		goto out_label;
	}
	rc = 0;
	end_block = 0;
	/* try all sizes - needed for ECKD devices */
	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
		mdsk_init_io(device, bsize, 0, &end_block);
		memset(bio, 0, sizeof(*bio));
		bio->type = MDSK_READ_REQ;
		bio->block_number = private->pt_block + 1;
		bio->buffer = label;
		memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
		private->iob.dev_nr = rdc_data->dev_nr;
		private->iob.key = 0;
		private->iob.flags = 0;	/* do synchronous io */
		private->iob.block_count = 1;
		private->iob.interrupt_params = 0;
		private->iob.bio_list = bio;
		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
		rc = dia250(&private->iob, RW_BIO);
		if (rc == 3) {
			pr_warn("%s: A 64-bit DIAG call failed\n",
				dev_name(&device->cdev->dev));
			rc = -EOPNOTSUPP;
			goto out_bio;
		}
		mdsk_term_io(device);
		if (rc == 0)
			break;
	}
	if (bsize > PAGE_SIZE) {
		pr_warn("%s: Accessing the DASD failed because of an incorrect format (rc=%d)\n",
			dev_name(&device->cdev->dev), rc);
		rc = -EIO;
		goto out_bio;
	}
	/* check for label block */
	if (memcmp(label->label_id, DASD_DIAG_CMS1,
		  sizeof(DASD_DIAG_CMS1)) == 0) {
		/* get formatted blocksize from label block */
		bsize = (unsigned int) label->block_size;
		block->blocks = (unsigned long) label->block_count;
	} else
		block->blocks = end_block;
	block->bp_block = bsize;
	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
	for (sb = 512; sb < bsize; sb = sb << 1)
		block->s2b_shift++;
	rc = mdsk_init_io(device, block->bp_block, 0, NULL);
	if (rc && (rc != 4)) {
		pr_warn("%s: DIAG initialization failed with rc=%d\n",
			dev_name(&device->cdev->dev), rc);
		rc = -EIO;
	} else {
		if (rc == 4)
			set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
		pr_info("%s: New DASD with %ld byte/block, total size %ld "
			"KB%s\n", dev_name(&device->cdev->dev),
			(unsigned long) block->bp_block,
			(unsigned long) (block->blocks <<
					 block->s2b_shift) >> 1,
			(rc == 4) ? ", read-only device" : "");
		rc = 0;
	}
out_bio:
	kfree(bio);
out_label:
	free_page((long) label);
out:
	if (rc) {
		device->block = NULL;
		dasd_free_block(block);
		device->private = NULL;
		kfree(private);
	}
	return rc;
}

/* Fill in virtual disk geometry for device. Return zero on success, non-zero
 * otherwise. */
static int
dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
{
	if (dasd_check_blocksize(block->bp_block) != 0)
		return -EINVAL;
	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
	geo->heads = 16;
	geo->sectors = 128 >> block->s2b_shift;
	return 0;
}

static dasd_erp_fn_t
dasd_diag_erp_action(struct dasd_ccw_req * cqr)
{
	return dasd_default_erp_action;
}

static dasd_erp_fn_t
dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
{
	return dasd_default_erp_postaction;
}

/* Create DASD request from block device request. Return pointer to new
 * request on success, ERR_PTR otherwise. */
static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
					       struct dasd_block *block,
					       struct request *req)
{
	struct dasd_ccw_req *cqr;
	struct dasd_diag_req *dreq;
	struct dasd_diag_bio *dbio;
	struct req_iterator iter;
	struct bio_vec bv;
	char *dst;
	unsigned int count;
	sector_t recid, first_rec, last_rec;
	unsigned int blksize, off;
	unsigned char rw_cmd;

	if (rq_data_dir(req) == READ)
		rw_cmd = MDSK_READ_REQ;
	else if (rq_data_dir(req) == WRITE)
		rw_cmd = MDSK_WRITE_REQ;
	else
		return ERR_PTR(-EINVAL);
	blksize = block->bp_block;
	/* Calculate record id of first and last block. */
	first_rec = blk_rq_pos(req) >> block->s2b_shift;
	last_rec =
		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
	/* Check struct bio and count the number of blocks for the request. */
	count = 0;
	rq_for_each_segment(bv, req, iter) {
		if (bv.bv_len & (blksize - 1))
			/* Fba can only do full blocks. */
			return ERR_PTR(-EINVAL);
		count += bv.bv_len >> (block->s2b_shift + 9);
	}
	/* Paranoia. */
	if (count != last_rec - first_rec + 1)
		return ERR_PTR(-EINVAL);
	/* Build the request */
	cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, struct_size(dreq, bio, count),
				   memdev, blk_mq_rq_to_pdu(req));
	if (IS_ERR(cqr))
		return cqr;

	dreq = (struct dasd_diag_req *) cqr->data;
	dreq->block_count = count;
	dbio = dreq->bio;
	recid = first_rec;
	rq_for_each_segment(bv, req, iter) {
		dst = page_address(bv.bv_page) + bv.bv_offset;
		for (off = 0; off < bv.bv_len; off += blksize) {
			memset(dbio, 0, sizeof (struct dasd_diag_bio));
			dbio->type = rw_cmd;
			dbio->block_number = recid + 1;
			dbio->buffer = dst;
			dbio++;
			dst += blksize;
			recid++;
		}
	}
	cqr->retries = memdev->default_retries;
	cqr->buildclk = get_tod_clock();
	if (blk_noretry_request(req) ||
	    block->base->features & DASD_FEATURE_FAILFAST)
		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->startdev = memdev;
	cqr->memdev = memdev;
	cqr->block = block;
	cqr->expires = memdev->default_expires * HZ;
	cqr->status = DASD_CQR_FILLED;
	return cqr;
}

/* Release DASD request. Return non-zero if request was successful, zero
 * otherwise. */
static int
dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
{
	int status;

	status = cqr->status == DASD_CQR_DONE;
	dasd_sfree_request(cqr, cqr->memdev);
	return status;
}

static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
{
	if (cqr->retries < 0)
		cqr->status = DASD_CQR_FAILED;
	else
		cqr->status = DASD_CQR_FILLED;
};

/* Fill in IOCTL data for device. */
static int
dasd_diag_fill_info(struct dasd_device * device,
		    struct dasd_information2_t * info)
{
	struct dasd_diag_private *private = device->private;

	info->label_block = (unsigned int) private->pt_block;
	info->FBA_layout = 1;
	info->format = DASD_FORMAT_LDL;
	info->characteristics_size = sizeof(private->rdc_data);
	memcpy(info->characteristics, &private->rdc_data,
	       sizeof(private->rdc_data));
	info->confdata_size = 0;
	return 0;
}

static void
dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
		     struct irb *stat)
{
	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
		    "dump sense not available for DIAG data");
}

/*
 * Initialize block layer request queue.
 */
static void dasd_diag_setup_blk_queue(struct dasd_block *block)
{
	unsigned int logical_block_size = block->bp_block;
	struct request_queue *q = block->request_queue;
	int max;

	max = DIAG_MAX_BLOCKS << block->s2b_shift;
	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
	q->limits.max_dev_sectors = max;
	blk_queue_logical_block_size(q, logical_block_size);
	blk_queue_max_hw_sectors(q, max);
	blk_queue_max_segments(q, USHRT_MAX);
	/* With page sized segments each segment can be translated into one idaw/tidaw */
	blk_queue_max_segment_size(q, PAGE_SIZE);
	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
}

static int dasd_diag_pe_handler(struct dasd_device *device,
				__u8 tbvpm, __u8 fcsecpm)
{
	return dasd_generic_verify_path(device, tbvpm);
}

static struct dasd_discipline dasd_diag_discipline = {
	.owner = THIS_MODULE,
	.name = "DIAG",
	.ebcname = "DIAG",
	.check_device = dasd_diag_check_device,
	.pe_handler = dasd_diag_pe_handler,
	.fill_geometry = dasd_diag_fill_geometry,
	.setup_blk_queue = dasd_diag_setup_blk_queue,
	.start_IO = dasd_start_diag,
	.term_IO = dasd_diag_term_IO,
	.handle_terminated_request = dasd_diag_handle_terminated_request,
	.erp_action = dasd_diag_erp_action,
	.erp_postaction = dasd_diag_erp_postaction,
	.build_cp = dasd_diag_build_cp,
	.free_cp = dasd_diag_free_cp,
	.dump_sense = dasd_diag_dump_sense,
	.fill_info = dasd_diag_fill_info,
};

static int __init
dasd_diag_init(void)
{
	if (!MACHINE_IS_VM) {
		pr_info("Discipline %s cannot be used without z/VM\n",
			dasd_diag_discipline.name);
		return -ENODEV;
	}
	ASCEBC(dasd_diag_discipline.ebcname, 4);

	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
	register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
	dasd_diag_discipline_pointer = &dasd_diag_discipline;
	return 0;
}

static void __exit
dasd_diag_cleanup(void)
{
	unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
	irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
	dasd_diag_discipline_pointer = NULL;
}

module_init(dasd_diag_init);
module_exit(dasd_diag_cleanup);