xref: /openbmc/linux/drivers/s390/block/dasd_diag.c (revision 1aae0560)
1 /*
2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3  * Based on.......: linux/drivers/s390/block/mdisk.c
4  * ...............: by Hartmunt Penner <hpenner@de.ibm.com>
5  * Bugreports.to..: <Linux390@de.ibm.com>
6  * Copyright IBM Corp. 1999, 2000
7  *
8  */
9 
10 #define KMSG_COMPONENT "dasd"
11 
12 #include <linux/kernel_stat.h>
13 #include <linux/stddef.h>
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/hdreg.h>
17 #include <linux/bio.h>
18 #include <linux/module.h>
19 #include <linux/init.h>
20 #include <linux/jiffies.h>
21 
22 #include <asm/dasd.h>
23 #include <asm/debug.h>
24 #include <asm/ebcdic.h>
25 #include <asm/io.h>
26 #include <asm/irq.h>
27 #include <asm/vtoc.h>
28 #include <asm/diag.h>
29 
30 #include "dasd_int.h"
31 #include "dasd_diag.h"
32 
33 #define PRINTK_HEADER "dasd(diag):"
34 
35 MODULE_LICENSE("GPL");
36 
37 /* The maximum number of blocks per request (max_blocks) is dependent on the
38  * amount of storage that is available in the static I/O buffer for each
39  * device. Currently each device gets 2 pages. We want to fit two requests
40  * into the available memory so that we can immediately start the next if one
41  * finishes. */
42 #define DIAG_MAX_BLOCKS	(((2 * PAGE_SIZE - sizeof(struct dasd_ccw_req) - \
43 			   sizeof(struct dasd_diag_req)) / \
44 		           sizeof(struct dasd_diag_bio)) / 2)
45 #define DIAG_MAX_RETRIES	32
46 #define DIAG_TIMEOUT		50
47 
48 static struct dasd_discipline dasd_diag_discipline;
49 
50 struct dasd_diag_private {
51 	struct dasd_diag_characteristics rdc_data;
52 	struct dasd_diag_rw_io iob;
53 	struct dasd_diag_init_io iib;
54 	blocknum_t pt_block;
55 	struct ccw_dev_id dev_id;
56 };
57 
58 struct dasd_diag_req {
59 	unsigned int block_count;
60 	struct dasd_diag_bio bio[0];
61 };
62 
63 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
64 
65 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
66  * and function code cmd.
67  * In case of an exception return 3. Otherwise return result of bitwise OR of
68  * resulting condition code and DIAG return code. */
69 static inline int dia250(void *iob, int cmd)
70 {
71 	register unsigned long reg2 asm ("2") = (unsigned long) iob;
72 	typedef union {
73 		struct dasd_diag_init_io init_io;
74 		struct dasd_diag_rw_io rw_io;
75 	} addr_type;
76 	int rc;
77 
78 	rc = 3;
79 	asm volatile(
80 		"	diag	2,%2,0x250\n"
81 		"0:	ipm	%0\n"
82 		"	srl	%0,28\n"
83 		"	or	%0,3\n"
84 		"1:\n"
85 		EX_TABLE(0b,1b)
86 		: "+d" (rc), "=m" (*(addr_type *) iob)
87 		: "d" (cmd), "d" (reg2), "m" (*(addr_type *) iob)
88 		: "3", "cc");
89 	return rc;
90 }
91 
92 /* Initialize block I/O to DIAG device using the specified blocksize and
93  * block offset. On success, return zero and set end_block to contain the
94  * number of blocks on the device minus the specified offset. Return non-zero
95  * otherwise. */
96 static inline int
97 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
98 	     blocknum_t offset, blocknum_t *end_block)
99 {
100 	struct dasd_diag_private *private;
101 	struct dasd_diag_init_io *iib;
102 	int rc;
103 
104 	private = (struct dasd_diag_private *) device->private;
105 	iib = &private->iib;
106 	memset(iib, 0, sizeof (struct dasd_diag_init_io));
107 
108 	iib->dev_nr = private->dev_id.devno;
109 	iib->block_size = blocksize;
110 	iib->offset = offset;
111 	iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
112 
113 	rc = dia250(iib, INIT_BIO);
114 
115 	if ((rc & 3) == 0 && end_block)
116 		*end_block = iib->end_block;
117 
118 	return rc;
119 }
120 
121 /* Remove block I/O environment for device. Return zero on success, non-zero
122  * otherwise. */
123 static inline int
124 mdsk_term_io(struct dasd_device * device)
125 {
126 	struct dasd_diag_private *private;
127 	struct dasd_diag_init_io *iib;
128 	int rc;
129 
130 	private = (struct dasd_diag_private *) device->private;
131 	iib = &private->iib;
132 	memset(iib, 0, sizeof (struct dasd_diag_init_io));
133 	iib->dev_nr = private->dev_id.devno;
134 	rc = dia250(iib, TERM_BIO);
135 	return rc;
136 }
137 
138 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
139  * environment. */
140 static void
141 dasd_diag_erp(struct dasd_device *device)
142 {
143 	int rc;
144 
145 	mdsk_term_io(device);
146 	rc = mdsk_init_io(device, device->block->bp_block, 0, NULL);
147 	if (rc == 4) {
148 		if (!(test_and_set_bit(DASD_FLAG_DEVICE_RO, &device->flags)))
149 			pr_warning("%s: The access mode of a DIAG device "
150 				   "changed to read-only\n",
151 				   dev_name(&device->cdev->dev));
152 		rc = 0;
153 	}
154 	if (rc)
155 		pr_warning("%s: DIAG ERP failed with "
156 			    "rc=%d\n", dev_name(&device->cdev->dev), rc);
157 }
158 
159 /* Start a given request at the device. Return zero on success, non-zero
160  * otherwise. */
161 static int
162 dasd_start_diag(struct dasd_ccw_req * cqr)
163 {
164 	struct dasd_device *device;
165 	struct dasd_diag_private *private;
166 	struct dasd_diag_req *dreq;
167 	int rc;
168 
169 	device = cqr->startdev;
170 	if (cqr->retries < 0) {
171 		DBF_DEV_EVENT(DBF_ERR, device, "DIAG start_IO: request %p "
172 			    "- no retry left)", cqr);
173 		cqr->status = DASD_CQR_ERROR;
174 		return -EIO;
175 	}
176 	private = (struct dasd_diag_private *) device->private;
177 	dreq = (struct dasd_diag_req *) cqr->data;
178 
179 	private->iob.dev_nr = private->dev_id.devno;
180 	private->iob.key = 0;
181 	private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
182 	private->iob.block_count = dreq->block_count;
183 	private->iob.interrupt_params = (addr_t) cqr;
184 	private->iob.bio_list = dreq->bio;
185 	private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
186 
187 	cqr->startclk = get_tod_clock();
188 	cqr->starttime = jiffies;
189 	cqr->retries--;
190 
191 	rc = dia250(&private->iob, RW_BIO);
192 	switch (rc) {
193 	case 0: /* Synchronous I/O finished successfully */
194 		cqr->stopclk = get_tod_clock();
195 		cqr->status = DASD_CQR_SUCCESS;
196 		/* Indicate to calling function that only a dasd_schedule_bh()
197 		   and no timer is needed */
198                 rc = -EACCES;
199 		break;
200 	case 8: /* Asynchronous I/O was started */
201 		cqr->status = DASD_CQR_IN_IO;
202 		rc = 0;
203 		break;
204 	default: /* Error condition */
205 		cqr->status = DASD_CQR_QUEUED;
206 		DBF_DEV_EVENT(DBF_WARNING, device, "dia250 returned rc=%d", rc);
207 		dasd_diag_erp(device);
208 		rc = -EIO;
209 		break;
210 	}
211 	cqr->intrc = rc;
212 	return rc;
213 }
214 
215 /* Terminate given request at the device. */
216 static int
217 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
218 {
219 	struct dasd_device *device;
220 
221 	device = cqr->startdev;
222 	mdsk_term_io(device);
223 	mdsk_init_io(device, device->block->bp_block, 0, NULL);
224 	cqr->status = DASD_CQR_CLEAR_PENDING;
225 	cqr->stopclk = get_tod_clock();
226 	dasd_schedule_device_bh(device);
227 	return 0;
228 }
229 
230 /* Handle external interruption. */
231 static void dasd_ext_handler(struct ext_code ext_code,
232 			     unsigned int param32, unsigned long param64)
233 {
234 	struct dasd_ccw_req *cqr, *next;
235 	struct dasd_device *device;
236 	unsigned long long expires;
237 	unsigned long flags;
238 	addr_t ip;
239 	int rc;
240 
241 	switch (ext_code.subcode >> 8) {
242 	case DASD_DIAG_CODE_31BIT:
243 		ip = (addr_t) param32;
244 		break;
245 	case DASD_DIAG_CODE_64BIT:
246 		ip = (addr_t) param64;
247 		break;
248 	default:
249 		return;
250 	}
251 	inc_irq_stat(IRQEXT_DSD);
252 	if (!ip) {		/* no intparm: unsolicited interrupt */
253 		DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
254 			      "interrupt");
255 		return;
256 	}
257 	cqr = (struct dasd_ccw_req *) ip;
258 	device = (struct dasd_device *) cqr->startdev;
259 	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
260 		DBF_DEV_EVENT(DBF_WARNING, device,
261 			    " magic number of dasd_ccw_req 0x%08X doesn't"
262 			    " match discipline 0x%08X",
263 			    cqr->magic, *(int *) (&device->discipline->name));
264 		return;
265 	}
266 
267 	/* get irq lock to modify request queue */
268 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
269 
270 	/* Check for a pending clear operation */
271 	if (cqr->status == DASD_CQR_CLEAR_PENDING) {
272 		cqr->status = DASD_CQR_CLEARED;
273 		dasd_device_clear_timer(device);
274 		dasd_schedule_device_bh(device);
275 		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
276 		return;
277 	}
278 
279 	cqr->stopclk = get_tod_clock();
280 
281 	expires = 0;
282 	if ((ext_code.subcode & 0xff) == 0) {
283 		cqr->status = DASD_CQR_SUCCESS;
284 		/* Start first request on queue if possible -> fast_io. */
285 		if (!list_empty(&device->ccw_queue)) {
286 			next = list_entry(device->ccw_queue.next,
287 					  struct dasd_ccw_req, devlist);
288 			if (next->status == DASD_CQR_QUEUED) {
289 				rc = dasd_start_diag(next);
290 				if (rc == 0)
291 					expires = next->expires;
292 			}
293 		}
294 	} else {
295 		cqr->status = DASD_CQR_QUEUED;
296 		DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
297 			      "request %p was %d (%d retries left)", cqr,
298 			      ext_code.subcode & 0xff, cqr->retries);
299 		dasd_diag_erp(device);
300 	}
301 
302 	if (expires != 0)
303 		dasd_device_set_timer(device, expires);
304 	else
305 		dasd_device_clear_timer(device);
306 	dasd_schedule_device_bh(device);
307 
308 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
309 }
310 
311 /* Check whether device can be controlled by DIAG discipline. Return zero on
312  * success, non-zero otherwise. */
313 static int
314 dasd_diag_check_device(struct dasd_device *device)
315 {
316 	struct dasd_block *block;
317 	struct dasd_diag_private *private;
318 	struct dasd_diag_characteristics *rdc_data;
319 	struct dasd_diag_bio bio;
320 	struct vtoc_cms_label *label;
321 	blocknum_t end_block;
322 	unsigned int sb, bsize;
323 	int rc;
324 
325 	private = (struct dasd_diag_private *) device->private;
326 	if (private == NULL) {
327 		private = kzalloc(sizeof(struct dasd_diag_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 = (void *) 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 = (void *) &(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 
363 	/* Figure out position of label block */
364 	switch (private->rdc_data.vdev_class) {
365 	case DEV_CLASS_FBA:
366 		private->pt_block = 1;
367 		break;
368 	case DEV_CLASS_ECKD:
369 		private->pt_block = 2;
370 		break;
371 	default:
372 		pr_warning("%s: Device type %d is not supported "
373 			   "in DIAG mode\n", dev_name(&device->cdev->dev),
374 			   private->rdc_data.vdev_class);
375 		rc = -EOPNOTSUPP;
376 		goto out;
377 	}
378 
379 	DBF_DEV_EVENT(DBF_INFO, device,
380 		      "%04X: %04X on real %04X/%02X",
381 		      rdc_data->dev_nr,
382 		      rdc_data->vdev_type,
383 		      rdc_data->rdev_type, rdc_data->rdev_model);
384 
385 	/* terminate all outstanding operations */
386 	mdsk_term_io(device);
387 
388 	/* figure out blocksize of device */
389 	label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
390 	if (label == NULL)  {
391 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
392 			    "No memory to allocate initialization request");
393 		rc = -ENOMEM;
394 		goto out;
395 	}
396 	rc = 0;
397 	end_block = 0;
398 	/* try all sizes - needed for ECKD devices */
399 	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
400 		mdsk_init_io(device, bsize, 0, &end_block);
401 		memset(&bio, 0, sizeof (struct dasd_diag_bio));
402 		bio.type = MDSK_READ_REQ;
403 		bio.block_number = private->pt_block + 1;
404 		bio.buffer = label;
405 		memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
406 		private->iob.dev_nr = rdc_data->dev_nr;
407 		private->iob.key = 0;
408 		private->iob.flags = 0;	/* do synchronous io */
409 		private->iob.block_count = 1;
410 		private->iob.interrupt_params = 0;
411 		private->iob.bio_list = &bio;
412 		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
413 		rc = dia250(&private->iob, RW_BIO);
414 		if (rc == 3) {
415 			pr_warning("%s: A 64-bit DIAG call failed\n",
416 				   dev_name(&device->cdev->dev));
417 			rc = -EOPNOTSUPP;
418 			goto out_label;
419 		}
420 		mdsk_term_io(device);
421 		if (rc == 0)
422 			break;
423 	}
424 	if (bsize > PAGE_SIZE) {
425 		pr_warning("%s: Accessing the DASD failed because of an "
426 			   "incorrect format (rc=%d)\n",
427 			   dev_name(&device->cdev->dev), rc);
428 		rc = -EIO;
429 		goto out_label;
430 	}
431 	/* check for label block */
432 	if (memcmp(label->label_id, DASD_DIAG_CMS1,
433 		  sizeof(DASD_DIAG_CMS1)) == 0) {
434 		/* get formatted blocksize from label block */
435 		bsize = (unsigned int) label->block_size;
436 		block->blocks = (unsigned long) label->block_count;
437 	} else
438 		block->blocks = end_block;
439 	block->bp_block = bsize;
440 	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
441 	for (sb = 512; sb < bsize; sb = sb << 1)
442 		block->s2b_shift++;
443 	rc = mdsk_init_io(device, block->bp_block, 0, NULL);
444 	if (rc && (rc != 4)) {
445 		pr_warning("%s: DIAG initialization failed with rc=%d\n",
446 			   dev_name(&device->cdev->dev), rc);
447 		rc = -EIO;
448 	} else {
449 		if (rc == 4)
450 			set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
451 		pr_info("%s: New DASD with %ld byte/block, total size %ld "
452 			"KB%s\n", dev_name(&device->cdev->dev),
453 			(unsigned long) block->bp_block,
454 			(unsigned long) (block->blocks <<
455 					 block->s2b_shift) >> 1,
456 			(rc == 4) ? ", read-only device" : "");
457 		rc = 0;
458 	}
459 out_label:
460 	free_page((long) label);
461 out:
462 	if (rc) {
463 		device->block = NULL;
464 		dasd_free_block(block);
465 		device->private = NULL;
466 		kfree(private);
467 	}
468 	return rc;
469 }
470 
471 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
472  * otherwise. */
473 static int
474 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
475 {
476 	if (dasd_check_blocksize(block->bp_block) != 0)
477 		return -EINVAL;
478 	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
479 	geo->heads = 16;
480 	geo->sectors = 128 >> block->s2b_shift;
481 	return 0;
482 }
483 
484 static dasd_erp_fn_t
485 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
486 {
487 	return dasd_default_erp_action;
488 }
489 
490 static dasd_erp_fn_t
491 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
492 {
493 	return dasd_default_erp_postaction;
494 }
495 
496 /* Create DASD request from block device request. Return pointer to new
497  * request on success, ERR_PTR otherwise. */
498 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
499 					       struct dasd_block *block,
500 					       struct request *req)
501 {
502 	struct dasd_ccw_req *cqr;
503 	struct dasd_diag_req *dreq;
504 	struct dasd_diag_bio *dbio;
505 	struct req_iterator iter;
506 	struct bio_vec *bv;
507 	char *dst;
508 	unsigned int count, datasize;
509 	sector_t recid, first_rec, last_rec;
510 	unsigned int blksize, off;
511 	unsigned char rw_cmd;
512 
513 	if (rq_data_dir(req) == READ)
514 		rw_cmd = MDSK_READ_REQ;
515 	else if (rq_data_dir(req) == WRITE)
516 		rw_cmd = MDSK_WRITE_REQ;
517 	else
518 		return ERR_PTR(-EINVAL);
519 	blksize = block->bp_block;
520 	/* Calculate record id of first and last block. */
521 	first_rec = blk_rq_pos(req) >> block->s2b_shift;
522 	last_rec =
523 		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
524 	/* Check struct bio and count the number of blocks for the request. */
525 	count = 0;
526 	rq_for_each_segment(bv, req, iter) {
527 		if (bv->bv_len & (blksize - 1))
528 			/* Fba can only do full blocks. */
529 			return ERR_PTR(-EINVAL);
530 		count += bv->bv_len >> (block->s2b_shift + 9);
531 	}
532 	/* Paranoia. */
533 	if (count != last_rec - first_rec + 1)
534 		return ERR_PTR(-EINVAL);
535 	/* Build the request */
536 	datasize = sizeof(struct dasd_diag_req) +
537 		count*sizeof(struct dasd_diag_bio);
538 	cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev);
539 	if (IS_ERR(cqr))
540 		return cqr;
541 
542 	dreq = (struct dasd_diag_req *) cqr->data;
543 	dreq->block_count = count;
544 	dbio = dreq->bio;
545 	recid = first_rec;
546 	rq_for_each_segment(bv, req, iter) {
547 		dst = page_address(bv->bv_page) + bv->bv_offset;
548 		for (off = 0; off < bv->bv_len; off += blksize) {
549 			memset(dbio, 0, sizeof (struct dasd_diag_bio));
550 			dbio->type = rw_cmd;
551 			dbio->block_number = recid + 1;
552 			dbio->buffer = dst;
553 			dbio++;
554 			dst += blksize;
555 			recid++;
556 		}
557 	}
558 	cqr->retries = DIAG_MAX_RETRIES;
559 	cqr->buildclk = get_tod_clock();
560 	if (blk_noretry_request(req) ||
561 	    block->base->features & DASD_FEATURE_FAILFAST)
562 		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
563 	cqr->startdev = memdev;
564 	cqr->memdev = memdev;
565 	cqr->block = block;
566 	cqr->expires = memdev->default_expires * HZ;
567 	cqr->status = DASD_CQR_FILLED;
568 	return cqr;
569 }
570 
571 /* Release DASD request. Return non-zero if request was successful, zero
572  * otherwise. */
573 static int
574 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
575 {
576 	int status;
577 
578 	status = cqr->status == DASD_CQR_DONE;
579 	dasd_sfree_request(cqr, cqr->memdev);
580 	return status;
581 }
582 
583 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
584 {
585 	cqr->status = DASD_CQR_FILLED;
586 };
587 
588 /* Fill in IOCTL data for device. */
589 static int
590 dasd_diag_fill_info(struct dasd_device * device,
591 		    struct dasd_information2_t * info)
592 {
593 	struct dasd_diag_private *private;
594 
595 	private = (struct dasd_diag_private *) device->private;
596 	info->label_block = (unsigned int) private->pt_block;
597 	info->FBA_layout = 1;
598 	info->format = DASD_FORMAT_LDL;
599 	info->characteristics_size = sizeof (struct dasd_diag_characteristics);
600 	memcpy(info->characteristics,
601 	       &((struct dasd_diag_private *) device->private)->rdc_data,
602 	       sizeof (struct dasd_diag_characteristics));
603 	info->confdata_size = 0;
604 	return 0;
605 }
606 
607 static void
608 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
609 		     struct irb *stat)
610 {
611 	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
612 		    "dump sense not available for DIAG data");
613 }
614 
615 static struct dasd_discipline dasd_diag_discipline = {
616 	.owner = THIS_MODULE,
617 	.name = "DIAG",
618 	.ebcname = "DIAG",
619 	.max_blocks = DIAG_MAX_BLOCKS,
620 	.check_device = dasd_diag_check_device,
621 	.verify_path = dasd_generic_verify_path,
622 	.fill_geometry = dasd_diag_fill_geometry,
623 	.start_IO = dasd_start_diag,
624 	.term_IO = dasd_diag_term_IO,
625 	.handle_terminated_request = dasd_diag_handle_terminated_request,
626 	.erp_action = dasd_diag_erp_action,
627 	.erp_postaction = dasd_diag_erp_postaction,
628 	.build_cp = dasd_diag_build_cp,
629 	.free_cp = dasd_diag_free_cp,
630 	.dump_sense = dasd_diag_dump_sense,
631 	.fill_info = dasd_diag_fill_info,
632 };
633 
634 static int __init
635 dasd_diag_init(void)
636 {
637 	if (!MACHINE_IS_VM) {
638 		pr_info("Discipline %s cannot be used without z/VM\n",
639 			dasd_diag_discipline.name);
640 		return -ENODEV;
641 	}
642 	ASCEBC(dasd_diag_discipline.ebcname, 4);
643 
644 	service_subclass_irq_register();
645 	register_external_interrupt(0x2603, dasd_ext_handler);
646 	dasd_diag_discipline_pointer = &dasd_diag_discipline;
647 	return 0;
648 }
649 
650 static void __exit
651 dasd_diag_cleanup(void)
652 {
653 	unregister_external_interrupt(0x2603, dasd_ext_handler);
654 	service_subclass_irq_unregister();
655 	dasd_diag_discipline_pointer = NULL;
656 }
657 
658 module_init(dasd_diag_init);
659 module_exit(dasd_diag_cleanup);
660