xref: /linux/drivers/s390/block/dasd_diag.c (revision c9933d494c54f72290831191c09bb8488bfd5905)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  * Based on.......: linux/drivers/s390/block/mdisk.c
5  * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
6  * Bugreports.to..: <Linux390@de.ibm.com>
7  * Copyright IBM Corp. 1999, 2000
8  *
9  */
10 
11 #define KMSG_COMPONENT "dasd"
12 
13 #include <linux/kernel_stat.h>
14 #include <linux/stddef.h>
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/hdreg.h>
18 #include <linux/bio.h>
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/jiffies.h>
22 #include <asm/asm-extable.h>
23 #include <asm/dasd.h>
24 #include <asm/debug.h>
25 #include <asm/diag.h>
26 #include <asm/ebcdic.h>
27 #include <asm/io.h>
28 #include <asm/irq.h>
29 #include <asm/vtoc.h>
30 
31 #include "dasd_int.h"
32 #include "dasd_diag.h"
33 
34 #define PRINTK_HEADER "dasd(diag):"
35 
36 MODULE_LICENSE("GPL");
37 
38 /* The maximum number of blocks per request (max_blocks) is dependent on the
39  * amount of storage that is available in the static I/O buffer for each
40  * device. Currently each device gets 2 pages. We want to fit two requests
41  * into the available memory so that we can immediately start the next if one
42  * finishes. */
43 #define DIAG_MAX_BLOCKS	(((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
44 			   sizeof(struct dasd_diag_req)) / \
45 		           sizeof(struct dasd_diag_bio)) / 2)
46 #define DIAG_MAX_RETRIES	32
47 #define DIAG_TIMEOUT		50
48 
49 static struct dasd_discipline dasd_diag_discipline;
50 
51 struct dasd_diag_private {
52 	struct dasd_diag_characteristics rdc_data;
53 	struct dasd_diag_rw_io iob;
54 	struct dasd_diag_init_io iib;
55 	blocknum_t pt_block;
56 	struct ccw_dev_id dev_id;
57 };
58 
59 struct dasd_diag_req {
60 	unsigned int block_count;
61 	struct dasd_diag_bio bio[];
62 };
63 
64 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
65 
66 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
67  * and function code cmd.
68  * In case of an exception return 3. Otherwise return result of bitwise OR of
69  * resulting condition code and DIAG return code. */
70 static inline int __dia250(void *iob, int cmd)
71 {
72 	union register_pair rx = { .even = (unsigned long)iob, };
73 	typedef union {
74 		struct dasd_diag_init_io init_io;
75 		struct dasd_diag_rw_io rw_io;
76 	} addr_type;
77 	int cc;
78 
79 	cc = 3;
80 	asm volatile(
81 		"	diag	%[rx],%[cmd],0x250\n"
82 		"0:	ipm	%[cc]\n"
83 		"	srl	%[cc],28\n"
84 		"1:\n"
85 		EX_TABLE(0b,1b)
86 		: [cc] "+&d" (cc), [rx] "+&d" (rx.pair), "+m" (*(addr_type *)iob)
87 		: [cmd] "d" (cmd)
88 		: "cc");
89 	return cc | rx.odd;
90 }
91 
92 static inline int dia250(void *iob, int cmd)
93 {
94 	diag_stat_inc(DIAG_STAT_X250);
95 	return __dia250(iob, cmd);
96 }
97 
98 /* Initialize block I/O to DIAG device using the specified blocksize and
99  * block offset. On success, return zero and set end_block to contain the
100  * number of blocks on the device minus the specified offset. Return non-zero
101  * otherwise. */
102 static inline int
103 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
104 	     blocknum_t offset, blocknum_t *end_block)
105 {
106 	struct dasd_diag_private *private = device->private;
107 	struct dasd_diag_init_io *iib = &private->iib;
108 	int rc;
109 
110 	memset(iib, 0, sizeof (struct dasd_diag_init_io));
111 
112 	iib->dev_nr = private->dev_id.devno;
113 	iib->block_size = blocksize;
114 	iib->offset = offset;
115 	iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
116 
117 	rc = dia250(iib, INIT_BIO);
118 
119 	if ((rc & 3) == 0 && end_block)
120 		*end_block = iib->end_block;
121 
122 	return rc;
123 }
124 
125 /* Remove block I/O environment for device. Return zero on success, non-zero
126  * otherwise. */
127 static inline int
128 mdsk_term_io(struct dasd_device * device)
129 {
130 	struct dasd_diag_private *private = device->private;
131 	struct dasd_diag_init_io *iib = &private->iib;
132 	int rc;
133 
134 	memset(iib, 0, sizeof (struct dasd_diag_init_io));
135 	iib->dev_nr = private->dev_id.devno;
136 	rc = dia250(iib, TERM_BIO);
137 	return rc;
138 }
139 
140 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
141  * environment. */
142 static void
143 dasd_diag_erp(struct dasd_device *device)
144 {
145 	int rc;
146 
147 	mdsk_term_io(device);
148 	rc = mdsk_init_io(device, device->block->bp_block, 0, NULL);
149 	if (rc == 4) {
150 		if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags)))
151 			pr_warn("%s: The access mode of a DIAG device changed to read-only\n",
152 				dev_name(&device->cdev->dev));
153 		rc = 0;
154 	}
155 	if (rc)
156 		pr_warn("%s: DIAG ERP failed with rc=%d\n",
157 			dev_name(&device->cdev->dev), rc);
158 }
159 
160 /* Start a given request at the device. Return zero on success, non-zero
161  * otherwise. */
162 static int
163 dasd_start_diag(struct dasd_ccw_req * cqr)
164 {
165 	struct dasd_device *device;
166 	struct dasd_diag_private *private;
167 	struct dasd_diag_req *dreq;
168 	int rc;
169 
170 	device = cqr->startdev;
171 	if (cqr->retries < 0) {
172 		DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
173 			    "- no retry left)", cqr);
174 		cqr->status = DASD_CQR_ERROR;
175 		return -EIO;
176 	}
177 	private = device->private;
178 	dreq = cqr->data;
179 
180 	private->iob.dev_nr = private->dev_id.devno;
181 	private->iob.key = 0;
182 	private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
183 	private->iob.block_count = dreq->block_count;
184 	private->iob.interrupt_params = (addr_t) cqr;
185 	private->iob.bio_list = dreq->bio;
186 	private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
187 
188 	cqr->startclk = get_tod_clock();
189 	cqr->starttime = jiffies;
190 	cqr->retries--;
191 
192 	rc = dia250(&private->iob, RW_BIO);
193 	switch (rc) {
194 	case 0: /* Synchronous I/O finished successfully */
195 		cqr->stopclk = get_tod_clock();
196 		cqr->status = DASD_CQR_SUCCESS;
197 		/* Indicate to calling function that only a dasd_schedule_bh()
198 		   and no timer is needed */
199                 rc = -EACCES;
200 		break;
201 	case 8: /* Asynchronous I/O was started */
202 		cqr->status = DASD_CQR_IN_IO;
203 		rc = 0;
204 		break;
205 	default: /* Error condition */
206 		cqr->status = DASD_CQR_QUEUED;
207 		DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
208 		dasd_diag_erp(device);
209 		rc = -EIO;
210 		break;
211 	}
212 	cqr->intrc = rc;
213 	return rc;
214 }
215 
216 /* Terminate given request at the device. */
217 static int
218 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
219 {
220 	struct dasd_device *device;
221 
222 	device = cqr->startdev;
223 	mdsk_term_io(device);
224 	mdsk_init_io(device, device->block->bp_block, 0, NULL);
225 	cqr->status = DASD_CQR_CLEAR_PENDING;
226 	cqr->stopclk = get_tod_clock();
227 	dasd_schedule_device_bh(device);
228 	return 0;
229 }
230 
231 /* Handle external interruption. */
232 static void dasd_ext_handler(struct ext_code ext_code,
233 			     unsigned int param32, unsigned long param64)
234 {
235 	struct dasd_ccw_req *cqr, *next;
236 	struct dasd_device *device;
237 	unsigned long expires;
238 	unsigned long flags;
239 	addr_t ip;
240 	int rc;
241 
242 	switch (ext_code.subcode >> 8) {
243 	case DASD_DIAG_CODE_31BIT:
244 		ip = (addr_t) param32;
245 		break;
246 	case DASD_DIAG_CODE_64BIT:
247 		ip = (addr_t) param64;
248 		break;
249 	default:
250 		return;
251 	}
252 	inc_irq_stat(IRQEXT_DSD);
253 	if (!ip) {		/* no intparm: unsolicited interrupt */
254 		DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
255 			      "interrupt");
256 		return;
257 	}
258 	cqr = (struct dasd_ccw_req *) ip;
259 	device = (struct dasd_device *) cqr->startdev;
260 	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
261 		DBF_DEV_EVENT(DBF_WARNING, device,
262 			    " magic number of dasd_ccw_req 0x%08X doesn't"
263 			    " match discipline 0x%08X",
264 			    cqr->magic, *(int *) (&device->discipline->name));
265 		return;
266 	}
267 
268 	/* get irq lock to modify request queue */
269 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
270 
271 	/* Check for a pending clear operation */
272 	if (cqr->status == DASD_CQR_CLEAR_PENDING) {
273 		cqr->status = DASD_CQR_CLEARED;
274 		dasd_device_clear_timer(device);
275 		dasd_schedule_device_bh(device);
276 		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
277 		return;
278 	}
279 
280 	cqr->stopclk = get_tod_clock();
281 
282 	expires = 0;
283 	if ((ext_code.subcode & 0xff) == 0) {
284 		cqr->status = DASD_CQR_SUCCESS;
285 		/* Start first request on queue if possible -> fast_io. */
286 		if (!list_empty(&device->ccw_queue)) {
287 			next = list_entry(device->ccw_queue.next,
288 					  struct dasd_ccw_req, devlist);
289 			if (next->status == DASD_CQR_QUEUED) {
290 				rc = dasd_start_diag(next);
291 				if (rc == 0)
292 					expires = next->expires;
293 			}
294 		}
295 	} else {
296 		cqr->status = DASD_CQR_QUEUED;
297 		DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
298 			      "request %p was %d (%d retries left)", cqr,
299 			      ext_code.subcode & 0xff, cqr->retries);
300 		dasd_diag_erp(device);
301 	}
302 
303 	if (expires != 0)
304 		dasd_device_set_timer(device, expires);
305 	else
306 		dasd_device_clear_timer(device);
307 	dasd_schedule_device_bh(device);
308 
309 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
310 }
311 
312 /* Check whether device can be controlled by DIAG discipline. Return zero on
313  * success, non-zero otherwise. */
314 static int
315 dasd_diag_check_device(struct dasd_device *device)
316 {
317 	struct dasd_diag_private *private = device->private;
318 	struct dasd_diag_characteristics *rdc_data;
319 	struct vtoc_cms_label *label;
320 	struct dasd_block *block;
321 	struct dasd_diag_bio *bio;
322 	unsigned int sb, bsize;
323 	blocknum_t end_block;
324 	int rc;
325 
326 	if (private == NULL) {
327 		private = kzalloc(sizeof(*private), GFP_KERNEL);
328 		if (private == NULL) {
329 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
330 				"Allocating memory for private DASD data "
331 				      "failed\n");
332 			return -ENOMEM;
333 		}
334 		ccw_device_get_id(device->cdev, &private->dev_id);
335 		device->private = private;
336 	}
337 	block = dasd_alloc_block();
338 	if (IS_ERR(block)) {
339 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
340 			    "could not allocate dasd block structure");
341 		device->private = NULL;
342 		kfree(private);
343 		return PTR_ERR(block);
344 	}
345 	device->block = block;
346 	block->base = device;
347 
348 	/* Read Device Characteristics */
349 	rdc_data = &private->rdc_data;
350 	rdc_data->dev_nr = private->dev_id.devno;
351 	rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
352 
353 	rc = diag210((struct diag210 *) rdc_data);
354 	if (rc) {
355 		DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device "
356 			    "information (rc=%d)", rc);
357 		rc = -EOPNOTSUPP;
358 		goto out;
359 	}
360 
361 	device->default_expires = DIAG_TIMEOUT;
362 	device->default_retries = DIAG_MAX_RETRIES;
363 
364 	/* Figure out position of label block */
365 	switch (private->rdc_data.vdev_class) {
366 	case DEV_CLASS_FBA:
367 		private->pt_block = 1;
368 		break;
369 	case DEV_CLASS_ECKD:
370 		private->pt_block = 2;
371 		break;
372 	default:
373 		pr_warn("%s: Device type %d is not supported in DIAG mode\n",
374 			dev_name(&device->cdev->dev),
375 			private->rdc_data.vdev_class);
376 		rc = -EOPNOTSUPP;
377 		goto out;
378 	}
379 
380 	DBF_DEV_EVENT(DBF_INFO, device,
381 		      "%04X: %04X on real %04X/%02X",
382 		      rdc_data->dev_nr,
383 		      rdc_data->vdev_type,
384 		      rdc_data->rdev_type, rdc_data->rdev_model);
385 
386 	/* terminate all outstanding operations */
387 	mdsk_term_io(device);
388 
389 	/* figure out blocksize of device */
390 	label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
391 	if (label == NULL)  {
392 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
393 			    "No memory to allocate initialization request");
394 		rc = -ENOMEM;
395 		goto out;
396 	}
397 	bio = kzalloc(sizeof(*bio), GFP_KERNEL);
398 	if (bio == NULL)  {
399 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
400 			      "No memory to allocate initialization bio");
401 		rc = -ENOMEM;
402 		goto out_label;
403 	}
404 	rc = 0;
405 	end_block = 0;
406 	/* try all sizes - needed for ECKD devices */
407 	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
408 		mdsk_init_io(device, bsize, 0, &end_block);
409 		memset(bio, 0, sizeof(*bio));
410 		bio->type = MDSK_READ_REQ;
411 		bio->block_number = private->pt_block + 1;
412 		bio->buffer = label;
413 		memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
414 		private->iob.dev_nr = rdc_data->dev_nr;
415 		private->iob.key = 0;
416 		private->iob.flags = 0;	/* do synchronous io */
417 		private->iob.block_count = 1;
418 		private->iob.interrupt_params = 0;
419 		private->iob.bio_list = bio;
420 		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
421 		rc = dia250(&private->iob, RW_BIO);
422 		if (rc == 3) {
423 			pr_warn("%s: A 64-bit DIAG call failed\n",
424 				dev_name(&device->cdev->dev));
425 			rc = -EOPNOTSUPP;
426 			goto out_bio;
427 		}
428 		mdsk_term_io(device);
429 		if (rc == 0)
430 			break;
431 	}
432 	if (bsize > PAGE_SIZE) {
433 		pr_warn("%s: Accessing the DASD failed because of an incorrect format (rc=%d)\n",
434 			dev_name(&device->cdev->dev), rc);
435 		rc = -EIO;
436 		goto out_bio;
437 	}
438 	/* check for label block */
439 	if (memcmp(label->label_id, DASD_DIAG_CMS1,
440 		  sizeof(DASD_DIAG_CMS1)) == 0) {
441 		/* get formatted blocksize from label block */
442 		bsize = (unsigned int) label->block_size;
443 		block->blocks = (unsigned long) label->block_count;
444 	} else
445 		block->blocks = end_block;
446 	block->bp_block = bsize;
447 	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
448 	for (sb = 512; sb < bsize; sb = sb << 1)
449 		block->s2b_shift++;
450 	rc = mdsk_init_io(device, block->bp_block, 0, NULL);
451 	if (rc && (rc != 4)) {
452 		pr_warn("%s: DIAG initialization failed with rc=%d\n",
453 			dev_name(&device->cdev->dev), rc);
454 		rc = -EIO;
455 	} else {
456 		if (rc == 4)
457 			set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
458 		pr_info("%s: New DASD with %ld byte/block, total size %ld "
459 			"KB%s\n", dev_name(&device->cdev->dev),
460 			(unsigned long) block->bp_block,
461 			(unsigned long) (block->blocks <<
462 					 block->s2b_shift) >> 1,
463 			(rc == 4) ? ", read-only device" : "");
464 		rc = 0;
465 	}
466 out_bio:
467 	kfree(bio);
468 out_label:
469 	free_page((long) label);
470 out:
471 	if (rc) {
472 		device->block = NULL;
473 		dasd_free_block(block);
474 		device->private = NULL;
475 		kfree(private);
476 	}
477 	return rc;
478 }
479 
480 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
481  * otherwise. */
482 static int
483 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
484 {
485 	if (dasd_check_blocksize(block->bp_block) != 0)
486 		return -EINVAL;
487 	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
488 	geo->heads = 16;
489 	geo->sectors = 128 >> block->s2b_shift;
490 	return 0;
491 }
492 
493 static dasd_erp_fn_t
494 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
495 {
496 	return dasd_default_erp_action;
497 }
498 
499 static dasd_erp_fn_t
500 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
501 {
502 	return dasd_default_erp_postaction;
503 }
504 
505 /* Create DASD request from block device request. Return pointer to new
506  * request on success, ERR_PTR otherwise. */
507 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
508 					       struct dasd_block *block,
509 					       struct request *req)
510 {
511 	struct dasd_ccw_req *cqr;
512 	struct dasd_diag_req *dreq;
513 	struct dasd_diag_bio *dbio;
514 	struct req_iterator iter;
515 	struct bio_vec bv;
516 	char *dst;
517 	unsigned int count;
518 	sector_t recid, first_rec, last_rec;
519 	unsigned int blksize, off;
520 	unsigned char rw_cmd;
521 
522 	if (rq_data_dir(req) == READ)
523 		rw_cmd = MDSK_READ_REQ;
524 	else if (rq_data_dir(req) == WRITE)
525 		rw_cmd = MDSK_WRITE_REQ;
526 	else
527 		return ERR_PTR(-EINVAL);
528 	blksize = block->bp_block;
529 	/* Calculate record id of first and last block. */
530 	first_rec = blk_rq_pos(req) >> block->s2b_shift;
531 	last_rec =
532 		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
533 	/* Check struct bio and count the number of blocks for the request. */
534 	count = 0;
535 	rq_for_each_segment(bv, req, iter) {
536 		if (bv.bv_len & (blksize - 1))
537 			/* Fba can only do full blocks. */
538 			return ERR_PTR(-EINVAL);
539 		count += bv.bv_len >> (block->s2b_shift + 9);
540 	}
541 	/* Paranoia. */
542 	if (count != last_rec - first_rec + 1)
543 		return ERR_PTR(-EINVAL);
544 	/* Build the request */
545 	cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, struct_size(dreq, bio, count),
546 				   memdev, blk_mq_rq_to_pdu(req));
547 	if (IS_ERR(cqr))
548 		return cqr;
549 
550 	dreq = (struct dasd_diag_req *) cqr->data;
551 	dreq->block_count = count;
552 	dbio = dreq->bio;
553 	recid = first_rec;
554 	rq_for_each_segment(bv, req, iter) {
555 		dst = bvec_virt(&bv);
556 		for (off = 0; off < bv.bv_len; off += blksize) {
557 			memset(dbio, 0, sizeof (struct dasd_diag_bio));
558 			dbio->type = rw_cmd;
559 			dbio->block_number = recid + 1;
560 			dbio->buffer = dst;
561 			dbio++;
562 			dst += blksize;
563 			recid++;
564 		}
565 	}
566 	cqr->retries = memdev->default_retries;
567 	cqr->buildclk = get_tod_clock();
568 	if (blk_noretry_request(req) ||
569 	    block->base->features & DASD_FEATURE_FAILFAST)
570 		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
571 	cqr->startdev = memdev;
572 	cqr->memdev = memdev;
573 	cqr->block = block;
574 	cqr->expires = memdev->default_expires * HZ;
575 	cqr->status = DASD_CQR_FILLED;
576 	return cqr;
577 }
578 
579 /* Release DASD request. Return non-zero if request was successful, zero
580  * otherwise. */
581 static int
582 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
583 {
584 	int status;
585 
586 	status = cqr->status == DASD_CQR_DONE;
587 	dasd_sfree_request(cqr, cqr->memdev);
588 	return status;
589 }
590 
591 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
592 {
593 	if (cqr->retries < 0)
594 		cqr->status = DASD_CQR_FAILED;
595 	else
596 		cqr->status = DASD_CQR_FILLED;
597 };
598 
599 /* Fill in IOCTL data for device. */
600 static int
601 dasd_diag_fill_info(struct dasd_device * device,
602 		    struct dasd_information2_t * info)
603 {
604 	struct dasd_diag_private *private = device->private;
605 
606 	info->label_block = (unsigned int) private->pt_block;
607 	info->FBA_layout = 1;
608 	info->format = DASD_FORMAT_LDL;
609 	info->characteristics_size = sizeof(private->rdc_data);
610 	memcpy(info->characteristics, &private->rdc_data,
611 	       sizeof(private->rdc_data));
612 	info->confdata_size = 0;
613 	return 0;
614 }
615 
616 static void
617 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
618 		     struct irb *stat)
619 {
620 	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
621 		    "dump sense not available for DIAG data");
622 }
623 
624 /*
625  * Initialize block layer request queue.
626  */
627 static void dasd_diag_setup_blk_queue(struct dasd_block *block)
628 {
629 	unsigned int logical_block_size = block->bp_block;
630 	struct request_queue *q = block->request_queue;
631 	int max;
632 
633 	max = DIAG_MAX_BLOCKS << block->s2b_shift;
634 	blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
635 	q->limits.max_dev_sectors = max;
636 	blk_queue_logical_block_size(q, logical_block_size);
637 	blk_queue_max_hw_sectors(q, max);
638 	blk_queue_max_segments(q, USHRT_MAX);
639 	/* With page sized segments each segment can be translated into one idaw/tidaw */
640 	blk_queue_max_segment_size(q, PAGE_SIZE);
641 	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
642 }
643 
644 static int dasd_diag_pe_handler(struct dasd_device *device,
645 				__u8 tbvpm, __u8 fcsecpm)
646 {
647 	return dasd_generic_verify_path(device, tbvpm);
648 }
649 
650 static struct dasd_discipline dasd_diag_discipline = {
651 	.owner = THIS_MODULE,
652 	.name = "DIAG",
653 	.ebcname = "DIAG",
654 	.check_device = dasd_diag_check_device,
655 	.pe_handler = dasd_diag_pe_handler,
656 	.fill_geometry = dasd_diag_fill_geometry,
657 	.setup_blk_queue = dasd_diag_setup_blk_queue,
658 	.start_IO = dasd_start_diag,
659 	.term_IO = dasd_diag_term_IO,
660 	.handle_terminated_request = dasd_diag_handle_terminated_request,
661 	.erp_action = dasd_diag_erp_action,
662 	.erp_postaction = dasd_diag_erp_postaction,
663 	.build_cp = dasd_diag_build_cp,
664 	.free_cp = dasd_diag_free_cp,
665 	.dump_sense = dasd_diag_dump_sense,
666 	.fill_info = dasd_diag_fill_info,
667 };
668 
669 static int __init
670 dasd_diag_init(void)
671 {
672 	if (!MACHINE_IS_VM) {
673 		pr_info("Discipline %s cannot be used without z/VM\n",
674 			dasd_diag_discipline.name);
675 		return -ENODEV;
676 	}
677 	ASCEBC(dasd_diag_discipline.ebcname, 4);
678 
679 	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
680 	register_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
681 	dasd_diag_discipline_pointer = &dasd_diag_discipline;
682 	return 0;
683 }
684 
685 static void __exit
686 dasd_diag_cleanup(void)
687 {
688 	unregister_external_irq(EXT_IRQ_CP_SERVICE, dasd_ext_handler);
689 	irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
690 	dasd_diag_discipline_pointer = NULL;
691 }
692 
693 module_init(dasd_diag_init);
694 module_exit(dasd_diag_cleanup);
695