xref: /openbmc/linux/drivers/s390/block/dasd_diag.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 /*
2  * File...........: linux/drivers/s390/block/dasd_diag.c
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  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
8  *
9  */
10 
11 #define KMSG_COMPONENT "dasd"
12 
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/s390_ext.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_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_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_clock();
226 	dasd_schedule_device_bh(device);
227 	return 0;
228 }
229 
230 /* Handle external interruption. */
231 static void dasd_ext_handler(unsigned int ext_int_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_int_code >> 24) {
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 	if (!ip) {		/* no intparm: unsolicited interrupt */
252 		DBF_EVENT(DBF_NOTICE, "%s", "caught unsolicited "
253 			      "interrupt");
254 		return;
255 	}
256 	cqr = (struct dasd_ccw_req *) ip;
257 	device = (struct dasd_device *) cqr->startdev;
258 	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
259 		DBF_DEV_EVENT(DBF_WARNING, device,
260 			    " magic number of dasd_ccw_req 0x%08X doesn't"
261 			    " match discipline 0x%08X",
262 			    cqr->magic, *(int *) (&device->discipline->name));
263 		return;
264 	}
265 
266 	/* get irq lock to modify request queue */
267 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
268 
269 	/* Check for a pending clear operation */
270 	if (cqr->status == DASD_CQR_CLEAR_PENDING) {
271 		cqr->status = DASD_CQR_CLEARED;
272 		dasd_device_clear_timer(device);
273 		dasd_schedule_device_bh(device);
274 		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
275 		return;
276 	}
277 
278 	cqr->stopclk = get_clock();
279 
280 	expires = 0;
281 	if ((ext_int_code & 0xff0000) == 0) {
282 		cqr->status = DASD_CQR_SUCCESS;
283 		/* Start first request on queue if possible -> fast_io. */
284 		if (!list_empty(&device->ccw_queue)) {
285 			next = list_entry(device->ccw_queue.next,
286 					  struct dasd_ccw_req, devlist);
287 			if (next->status == DASD_CQR_QUEUED) {
288 				rc = dasd_start_diag(next);
289 				if (rc == 0)
290 					expires = next->expires;
291 			}
292 		}
293 	} else {
294 		cqr->status = DASD_CQR_QUEUED;
295 		DBF_DEV_EVENT(DBF_DEBUG, device, "interrupt status for "
296 			      "request %p was %d (%d retries left)", cqr,
297 			      (ext_int_code >> 16) & 0xff, cqr->retries);
298 		dasd_diag_erp(device);
299 	}
300 
301 	if (expires != 0)
302 		dasd_device_set_timer(device, expires);
303 	else
304 		dasd_device_clear_timer(device);
305 	dasd_schedule_device_bh(device);
306 
307 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
308 }
309 
310 /* Check whether device can be controlled by DIAG discipline. Return zero on
311  * success, non-zero otherwise. */
312 static int
313 dasd_diag_check_device(struct dasd_device *device)
314 {
315 	struct dasd_block *block;
316 	struct dasd_diag_private *private;
317 	struct dasd_diag_characteristics *rdc_data;
318 	struct dasd_diag_bio bio;
319 	struct vtoc_cms_label *label;
320 	blocknum_t end_block;
321 	unsigned int sb, bsize;
322 	int rc;
323 
324 	private = (struct dasd_diag_private *) device->private;
325 	if (private == NULL) {
326 		private = kzalloc(sizeof(struct dasd_diag_private),GFP_KERNEL);
327 		if (private == NULL) {
328 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
329 				"Allocating memory for private DASD data "
330 				      "failed\n");
331 			return -ENOMEM;
332 		}
333 		ccw_device_get_id(device->cdev, &private->dev_id);
334 		device->private = (void *) private;
335 	}
336 	block = dasd_alloc_block();
337 	if (IS_ERR(block)) {
338 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
339 			    "could not allocate dasd block structure");
340 		device->private = NULL;
341 		kfree(private);
342 		return PTR_ERR(block);
343 	}
344 	device->block = block;
345 	block->base = device;
346 
347 	/* Read Device Characteristics */
348 	rdc_data = (void *) &(private->rdc_data);
349 	rdc_data->dev_nr = private->dev_id.devno;
350 	rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
351 
352 	rc = diag210((struct diag210 *) rdc_data);
353 	if (rc) {
354 		DBF_DEV_EVENT(DBF_WARNING, device, "failed to retrieve device "
355 			    "information (rc=%d)", rc);
356 		rc = -EOPNOTSUPP;
357 		goto out;
358 	}
359 
360 	device->default_expires = DIAG_TIMEOUT;
361 
362 	/* Figure out position of label block */
363 	switch (private->rdc_data.vdev_class) {
364 	case DEV_CLASS_FBA:
365 		private->pt_block = 1;
366 		break;
367 	case DEV_CLASS_ECKD:
368 		private->pt_block = 2;
369 		break;
370 	default:
371 		pr_warning("%s: Device type %d is not supported "
372 			   "in DIAG mode\n", dev_name(&device->cdev->dev),
373 			   private->rdc_data.vdev_class);
374 		rc = -EOPNOTSUPP;
375 		goto out;
376 	}
377 
378 	DBF_DEV_EVENT(DBF_INFO, device,
379 		      "%04X: %04X on real %04X/%02X",
380 		      rdc_data->dev_nr,
381 		      rdc_data->vdev_type,
382 		      rdc_data->rdev_type, rdc_data->rdev_model);
383 
384 	/* terminate all outstanding operations */
385 	mdsk_term_io(device);
386 
387 	/* figure out blocksize of device */
388 	label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
389 	if (label == NULL)  {
390 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
391 			    "No memory to allocate initialization request");
392 		rc = -ENOMEM;
393 		goto out;
394 	}
395 	rc = 0;
396 	end_block = 0;
397 	/* try all sizes - needed for ECKD devices */
398 	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
399 		mdsk_init_io(device, bsize, 0, &end_block);
400 		memset(&bio, 0, sizeof (struct dasd_diag_bio));
401 		bio.type = MDSK_READ_REQ;
402 		bio.block_number = private->pt_block + 1;
403 		bio.buffer = label;
404 		memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
405 		private->iob.dev_nr = rdc_data->dev_nr;
406 		private->iob.key = 0;
407 		private->iob.flags = 0;	/* do synchronous io */
408 		private->iob.block_count = 1;
409 		private->iob.interrupt_params = 0;
410 		private->iob.bio_list = &bio;
411 		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
412 		rc = dia250(&private->iob, RW_BIO);
413 		if (rc == 3) {
414 			pr_warning("%s: A 64-bit DIAG call failed\n",
415 				   dev_name(&device->cdev->dev));
416 			rc = -EOPNOTSUPP;
417 			goto out_label;
418 		}
419 		mdsk_term_io(device);
420 		if (rc == 0)
421 			break;
422 	}
423 	if (bsize > PAGE_SIZE) {
424 		pr_warning("%s: Accessing the DASD failed because of an "
425 			   "incorrect format (rc=%d)\n",
426 			   dev_name(&device->cdev->dev), rc);
427 		rc = -EIO;
428 		goto out_label;
429 	}
430 	/* check for label block */
431 	if (memcmp(label->label_id, DASD_DIAG_CMS1,
432 		  sizeof(DASD_DIAG_CMS1)) == 0) {
433 		/* get formatted blocksize from label block */
434 		bsize = (unsigned int) label->block_size;
435 		block->blocks = (unsigned long) label->block_count;
436 	} else
437 		block->blocks = end_block;
438 	block->bp_block = bsize;
439 	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
440 	for (sb = 512; sb < bsize; sb = sb << 1)
441 		block->s2b_shift++;
442 	rc = mdsk_init_io(device, block->bp_block, 0, NULL);
443 	if (rc && (rc != 4)) {
444 		pr_warning("%s: DIAG initialization failed with rc=%d\n",
445 			   dev_name(&device->cdev->dev), rc);
446 		rc = -EIO;
447 	} else {
448 		if (rc == 4)
449 			set_bit(DASD_FLAG_DEVICE_RO, &device->flags);
450 		pr_info("%s: New DASD with %ld byte/block, total size %ld "
451 			"KB%s\n", dev_name(&device->cdev->dev),
452 			(unsigned long) block->bp_block,
453 			(unsigned long) (block->blocks <<
454 					 block->s2b_shift) >> 1,
455 			(rc == 4) ? ", read-only device" : "");
456 		rc = 0;
457 	}
458 out_label:
459 	free_page((long) label);
460 out:
461 	if (rc) {
462 		device->block = NULL;
463 		dasd_free_block(block);
464 		device->private = NULL;
465 		kfree(private);
466 	}
467 	return rc;
468 }
469 
470 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
471  * otherwise. */
472 static int
473 dasd_diag_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
474 {
475 	if (dasd_check_blocksize(block->bp_block) != 0)
476 		return -EINVAL;
477 	geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
478 	geo->heads = 16;
479 	geo->sectors = 128 >> block->s2b_shift;
480 	return 0;
481 }
482 
483 static dasd_erp_fn_t
484 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
485 {
486 	return dasd_default_erp_action;
487 }
488 
489 static dasd_erp_fn_t
490 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
491 {
492 	return dasd_default_erp_postaction;
493 }
494 
495 /* Create DASD request from block device request. Return pointer to new
496  * request on success, ERR_PTR otherwise. */
497 static struct dasd_ccw_req *dasd_diag_build_cp(struct dasd_device *memdev,
498 					       struct dasd_block *block,
499 					       struct request *req)
500 {
501 	struct dasd_ccw_req *cqr;
502 	struct dasd_diag_req *dreq;
503 	struct dasd_diag_bio *dbio;
504 	struct req_iterator iter;
505 	struct bio_vec *bv;
506 	char *dst;
507 	unsigned int count, datasize;
508 	sector_t recid, first_rec, last_rec;
509 	unsigned int blksize, off;
510 	unsigned char rw_cmd;
511 
512 	if (rq_data_dir(req) == READ)
513 		rw_cmd = MDSK_READ_REQ;
514 	else if (rq_data_dir(req) == WRITE)
515 		rw_cmd = MDSK_WRITE_REQ;
516 	else
517 		return ERR_PTR(-EINVAL);
518 	blksize = block->bp_block;
519 	/* Calculate record id of first and last block. */
520 	first_rec = blk_rq_pos(req) >> block->s2b_shift;
521 	last_rec =
522 		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
523 	/* Check struct bio and count the number of blocks for the request. */
524 	count = 0;
525 	rq_for_each_segment(bv, req, iter) {
526 		if (bv->bv_len & (blksize - 1))
527 			/* Fba can only do full blocks. */
528 			return ERR_PTR(-EINVAL);
529 		count += bv->bv_len >> (block->s2b_shift + 9);
530 	}
531 	/* Paranoia. */
532 	if (count != last_rec - first_rec + 1)
533 		return ERR_PTR(-EINVAL);
534 	/* Build the request */
535 	datasize = sizeof(struct dasd_diag_req) +
536 		count*sizeof(struct dasd_diag_bio);
537 	cqr = dasd_smalloc_request(DASD_DIAG_MAGIC, 0, datasize, memdev);
538 	if (IS_ERR(cqr))
539 		return cqr;
540 
541 	dreq = (struct dasd_diag_req *) cqr->data;
542 	dreq->block_count = count;
543 	dbio = dreq->bio;
544 	recid = first_rec;
545 	rq_for_each_segment(bv, req, iter) {
546 		dst = page_address(bv->bv_page) + bv->bv_offset;
547 		for (off = 0; off < bv->bv_len; off += blksize) {
548 			memset(dbio, 0, sizeof (struct dasd_diag_bio));
549 			dbio->type = rw_cmd;
550 			dbio->block_number = recid + 1;
551 			dbio->buffer = dst;
552 			dbio++;
553 			dst += blksize;
554 			recid++;
555 		}
556 	}
557 	cqr->retries = DIAG_MAX_RETRIES;
558 	cqr->buildclk = get_clock();
559 	if (blk_noretry_request(req) ||
560 	    block->base->features & DASD_FEATURE_FAILFAST)
561 		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
562 	cqr->startdev = memdev;
563 	cqr->memdev = memdev;
564 	cqr->block = block;
565 	cqr->expires = memdev->default_expires * HZ;
566 	cqr->status = DASD_CQR_FILLED;
567 	return cqr;
568 }
569 
570 /* Release DASD request. Return non-zero if request was successful, zero
571  * otherwise. */
572 static int
573 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
574 {
575 	int status;
576 
577 	status = cqr->status == DASD_CQR_DONE;
578 	dasd_sfree_request(cqr, cqr->memdev);
579 	return status;
580 }
581 
582 static void dasd_diag_handle_terminated_request(struct dasd_ccw_req *cqr)
583 {
584 	cqr->status = DASD_CQR_FILLED;
585 };
586 
587 /* Fill in IOCTL data for device. */
588 static int
589 dasd_diag_fill_info(struct dasd_device * device,
590 		    struct dasd_information2_t * info)
591 {
592 	struct dasd_diag_private *private;
593 
594 	private = (struct dasd_diag_private *) device->private;
595 	info->label_block = (unsigned int) private->pt_block;
596 	info->FBA_layout = 1;
597 	info->format = DASD_FORMAT_LDL;
598 	info->characteristics_size = sizeof (struct dasd_diag_characteristics);
599 	memcpy(info->characteristics,
600 	       &((struct dasd_diag_private *) device->private)->rdc_data,
601 	       sizeof (struct dasd_diag_characteristics));
602 	info->confdata_size = 0;
603 	return 0;
604 }
605 
606 static void
607 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
608 		     struct irb *stat)
609 {
610 	DBF_DEV_EVENT(DBF_WARNING, device, "%s",
611 		    "dump sense not available for DIAG data");
612 }
613 
614 static struct dasd_discipline dasd_diag_discipline = {
615 	.owner = THIS_MODULE,
616 	.name = "DIAG",
617 	.ebcname = "DIAG",
618 	.max_blocks = DIAG_MAX_BLOCKS,
619 	.check_device = dasd_diag_check_device,
620 	.fill_geometry = dasd_diag_fill_geometry,
621 	.start_IO = dasd_start_diag,
622 	.term_IO = dasd_diag_term_IO,
623 	.handle_terminated_request = dasd_diag_handle_terminated_request,
624 	.erp_action = dasd_diag_erp_action,
625 	.erp_postaction = dasd_diag_erp_postaction,
626 	.build_cp = dasd_diag_build_cp,
627 	.free_cp = dasd_diag_free_cp,
628 	.dump_sense = dasd_diag_dump_sense,
629 	.fill_info = dasd_diag_fill_info,
630 };
631 
632 static int __init
633 dasd_diag_init(void)
634 {
635 	if (!MACHINE_IS_VM) {
636 		pr_info("Discipline %s cannot be used without z/VM\n",
637 			dasd_diag_discipline.name);
638 		return -ENODEV;
639 	}
640 	ASCEBC(dasd_diag_discipline.ebcname, 4);
641 
642 	ctl_set_bit(0, 9);
643 	register_external_interrupt(0x2603, dasd_ext_handler);
644 	dasd_diag_discipline_pointer = &dasd_diag_discipline;
645 	return 0;
646 }
647 
648 static void __exit
649 dasd_diag_cleanup(void)
650 {
651 	unregister_external_interrupt(0x2603, dasd_ext_handler);
652 	ctl_clear_bit(0, 9);
653 	dasd_diag_discipline_pointer = NULL;
654 }
655 
656 module_init(dasd_diag_init);
657 module_exit(dasd_diag_cleanup);
658