xref: /openbmc/linux/drivers/s390/block/dasd_diag.c (revision 87c2ce3b)
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  * $Revision: 1.53 $
10  */
11 
12 #include <linux/config.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/s390_ext.h>
27 #include <asm/todclk.h>
28 #include <asm/vtoc.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 * HZ
47 
48 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 };
56 
57 struct dasd_diag_req {
58 	unsigned int block_count;
59 	struct dasd_diag_bio bio[0];
60 };
61 
62 static const u8 DASD_DIAG_CMS1[] = { 0xc3, 0xd4, 0xe2, 0xf1 };/* EBCDIC CMS1 */
63 
64 /* Perform DIAG250 call with block I/O parameter list iob (input and output)
65  * and function code cmd.
66  * In case of an exception return 3. Otherwise return result of bitwise OR of
67  * resulting condition code and DIAG return code. */
68 static __inline__ int
69 dia250(void *iob, int cmd)
70 {
71 	typedef union {
72 		struct dasd_diag_init_io init_io;
73 		struct dasd_diag_rw_io rw_io;
74 	} addr_type;
75 	int rc;
76 
77 	__asm__ __volatile__(
78 #ifdef CONFIG_64BIT
79 		"	lghi	%0,3\n"
80 		"	lgr	0,%3\n"
81 		"	diag	0,%2,0x250\n"
82 		"0:	ipm	%0\n"
83 		"	srl	%0,28\n"
84 		"	or	%0,1\n"
85 		"1:\n"
86 		".section __ex_table,\"a\"\n"
87 		"	.align 8\n"
88 		"	.quad  0b,1b\n"
89 		".previous\n"
90 #else
91 		"	lhi	%0,3\n"
92 		"	lr	0,%3\n"
93 		"	diag	0,%2,0x250\n"
94 		"0:	ipm	%0\n"
95 		"	srl	%0,28\n"
96 		"	or	%0,1\n"
97 		"1:\n"
98 		".section __ex_table,\"a\"\n"
99 		"	.align 4\n"
100 		"	.long 0b,1b\n"
101 		".previous\n"
102 #endif
103 		: "=&d" (rc), "=m" (*(addr_type *) iob)
104 		: "d" (cmd), "d" (iob), "m" (*(addr_type *) iob)
105 		: "0", "1", "cc");
106 	return rc;
107 }
108 
109 /* Initialize block I/O to DIAG device using the specified blocksize and
110  * block offset. On success, return zero and set end_block to contain the
111  * number of blocks on the device minus the specified offset. Return non-zero
112  * otherwise. */
113 static __inline__ int
114 mdsk_init_io(struct dasd_device *device, unsigned int blocksize,
115 	     blocknum_t offset, blocknum_t *end_block)
116 {
117 	struct dasd_diag_private *private;
118 	struct dasd_diag_init_io *iib;
119 	int rc;
120 
121 	private = (struct dasd_diag_private *) device->private;
122 	iib = &private->iib;
123 	memset(iib, 0, sizeof (struct dasd_diag_init_io));
124 
125 	iib->dev_nr = _ccw_device_get_device_number(device->cdev);
126 	iib->block_size = blocksize;
127 	iib->offset = offset;
128 	iib->flaga = DASD_DIAG_FLAGA_DEFAULT;
129 
130 	rc = dia250(iib, INIT_BIO);
131 
132 	if ((rc & 3) == 0 && end_block)
133 		*end_block = iib->end_block;
134 
135 	return rc;
136 }
137 
138 /* Remove block I/O environment for device. Return zero on success, non-zero
139  * otherwise. */
140 static __inline__ int
141 mdsk_term_io(struct dasd_device * device)
142 {
143 	struct dasd_diag_private *private;
144 	struct dasd_diag_init_io *iib;
145 	int rc;
146 
147 	private = (struct dasd_diag_private *) device->private;
148 	iib = &private->iib;
149 	memset(iib, 0, sizeof (struct dasd_diag_init_io));
150 	iib->dev_nr = _ccw_device_get_device_number(device->cdev);
151 	rc = dia250(iib, TERM_BIO);
152 	return rc;
153 }
154 
155 /* Error recovery for failed DIAG requests - try to reestablish the DIAG
156  * environment. */
157 static void
158 dasd_diag_erp(struct dasd_device *device)
159 {
160 	int rc;
161 
162 	mdsk_term_io(device);
163 	rc = mdsk_init_io(device, device->bp_block, 0, NULL);
164 	if (rc)
165 		DEV_MESSAGE(KERN_WARNING, device, "DIAG ERP unsuccessful, "
166 			    "rc=%d", rc);
167 }
168 
169 /* Start a given request at the device. Return zero on success, non-zero
170  * otherwise. */
171 static int
172 dasd_start_diag(struct dasd_ccw_req * cqr)
173 {
174 	struct dasd_device *device;
175 	struct dasd_diag_private *private;
176 	struct dasd_diag_req *dreq;
177 	int rc;
178 
179 	device = cqr->device;
180 	if (cqr->retries < 0) {
181 		DEV_MESSAGE(KERN_WARNING, device, "DIAG start_IO: request %p "
182 			    "- no retry left)", cqr);
183 		cqr->status = DASD_CQR_FAILED;
184 		return -EIO;
185 	}
186 	private = (struct dasd_diag_private *) device->private;
187 	dreq = (struct dasd_diag_req *) cqr->data;
188 
189 	private->iob.dev_nr = _ccw_device_get_device_number(device->cdev);
190 	private->iob.key = 0;
191 	private->iob.flags = DASD_DIAG_RWFLAG_ASYNC;
192 	private->iob.block_count = dreq->block_count;
193 	private->iob.interrupt_params = (addr_t) cqr;
194 	private->iob.bio_list = dreq->bio;
195 	private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
196 
197 	cqr->startclk = get_clock();
198 	cqr->starttime = jiffies;
199 	cqr->retries--;
200 
201 	rc = dia250(&private->iob, RW_BIO);
202 	switch (rc) {
203 	case 0: /* Synchronous I/O finished successfully */
204 		cqr->stopclk = get_clock();
205 		cqr->status = DASD_CQR_DONE;
206 		/* Indicate to calling function that only a dasd_schedule_bh()
207 		   and no timer is needed */
208                 rc = -EACCES;
209 		break;
210 	case 8: /* Asynchronous I/O was started */
211 		cqr->status = DASD_CQR_IN_IO;
212 		rc = 0;
213 		break;
214 	default: /* Error condition */
215 		cqr->status = DASD_CQR_QUEUED;
216 		DEV_MESSAGE(KERN_WARNING, device, "dia250 returned rc=%d", rc);
217 		dasd_diag_erp(device);
218 		rc = -EIO;
219 		break;
220 	}
221 	return rc;
222 }
223 
224 /* Terminate given request at the device. */
225 static int
226 dasd_diag_term_IO(struct dasd_ccw_req * cqr)
227 {
228 	struct dasd_device *device;
229 
230 	device = cqr->device;
231 	mdsk_term_io(device);
232 	mdsk_init_io(device, device->bp_block, 0, NULL);
233 	cqr->status = DASD_CQR_CLEAR;
234 	cqr->stopclk = get_clock();
235 	dasd_schedule_bh(device);
236 	return 0;
237 }
238 
239 /* Handle external interruption. */
240 static void
241 dasd_ext_handler(struct pt_regs *regs, __u16 code)
242 {
243 	struct dasd_ccw_req *cqr, *next;
244 	struct dasd_device *device;
245 	unsigned long long expires;
246 	unsigned long flags;
247 	u8 int_code, status;
248 	addr_t ip;
249 	int rc;
250 
251 	int_code = *((u8 *) DASD_DIAG_LC_INT_CODE);
252 	status = *((u8 *) DASD_DIAG_LC_INT_STATUS);
253 	switch (int_code) {
254 	case DASD_DIAG_CODE_31BIT:
255 		ip = (addr_t) *((u32 *) DASD_DIAG_LC_INT_PARM_31BIT);
256 		break;
257 	case DASD_DIAG_CODE_64BIT:
258 		ip = (addr_t) *((u64 *) DASD_DIAG_LC_INT_PARM_64BIT);
259 		break;
260 	default:
261 		return;
262 	}
263 	if (!ip) {		/* no intparm: unsolicited interrupt */
264 		MESSAGE(KERN_DEBUG, "%s", "caught unsolicited interrupt");
265 		return;
266 	}
267 	cqr = (struct dasd_ccw_req *) ip;
268 	device = (struct dasd_device *) cqr->device;
269 	if (strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
270 		DEV_MESSAGE(KERN_WARNING, device,
271 			    " magic number of dasd_ccw_req 0x%08X doesn't"
272 			    " match discipline 0x%08X",
273 			    cqr->magic, *(int *) (&device->discipline->name));
274 		return;
275 	}
276 
277 	/* get irq lock to modify request queue */
278 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
279 
280 	/* Check for a pending clear operation */
281 	if (cqr->status == DASD_CQR_CLEAR) {
282 		cqr->status = DASD_CQR_QUEUED;
283 		dasd_clear_timer(device);
284 		dasd_schedule_bh(device);
285 		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
286 		return;
287 	}
288 
289 	cqr->stopclk = get_clock();
290 
291 	expires = 0;
292 	if (status == 0) {
293 		cqr->status = DASD_CQR_DONE;
294 		/* Start first request on queue if possible -> fast_io. */
295 		if (!list_empty(&device->ccw_queue)) {
296 			next = list_entry(device->ccw_queue.next,
297 					  struct dasd_ccw_req, list);
298 			if (next->status == DASD_CQR_QUEUED) {
299 				rc = dasd_start_diag(next);
300 				if (rc == 0)
301 					expires = next->expires;
302 				else if (rc != -EACCES)
303 					DEV_MESSAGE(KERN_WARNING, device, "%s",
304 						    "Interrupt fastpath "
305 						    "failed!");
306 			}
307 		}
308 	} else {
309 		cqr->status = DASD_CQR_QUEUED;
310 		DEV_MESSAGE(KERN_WARNING, device, "interrupt status for "
311 			    "request %p was %d (%d retries left)", cqr, status,
312 			    cqr->retries);
313 		dasd_diag_erp(device);
314 	}
315 
316 	if (expires != 0)
317 		dasd_set_timer(device, expires);
318 	else
319 		dasd_clear_timer(device);
320 	dasd_schedule_bh(device);
321 
322 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
323 }
324 
325 /* Check whether device can be controlled by DIAG discipline. Return zero on
326  * success, non-zero otherwise. */
327 static int
328 dasd_diag_check_device(struct dasd_device *device)
329 {
330 	struct dasd_diag_private *private;
331 	struct dasd_diag_characteristics *rdc_data;
332 	struct dasd_diag_bio bio;
333 	struct vtoc_cms_label *label;
334 	blocknum_t end_block;
335 	unsigned int sb, bsize;
336 	int rc;
337 
338 	private = (struct dasd_diag_private *) device->private;
339 	if (private == NULL) {
340 		private = kmalloc(sizeof(struct dasd_diag_private),GFP_KERNEL);
341 		if (private == NULL) {
342 			DEV_MESSAGE(KERN_WARNING, device, "%s",
343 				"memory allocation failed for private data");
344 			return -ENOMEM;
345 		}
346 		device->private = (void *) private;
347 	}
348 	/* Read Device Characteristics */
349 	rdc_data = (void *) &(private->rdc_data);
350 	rdc_data->dev_nr = _ccw_device_get_device_number(device->cdev);
351 	rdc_data->rdc_len = sizeof (struct dasd_diag_characteristics);
352 
353 	rc = diag210((struct diag210 *) rdc_data);
354 	if (rc) {
355 		DEV_MESSAGE(KERN_WARNING, device, "failed to retrieve device "
356 			    "information (rc=%d)", rc);
357 		return -ENOTSUPP;
358 	}
359 
360 	/* Figure out position of label block */
361 	switch (private->rdc_data.vdev_class) {
362 	case DEV_CLASS_FBA:
363 		private->pt_block = 1;
364 		break;
365 	case DEV_CLASS_ECKD:
366 		private->pt_block = 2;
367 		break;
368 	default:
369 		DEV_MESSAGE(KERN_WARNING, device, "unsupported device class "
370 			    "(class=%d)", private->rdc_data.vdev_class);
371 		return -ENOTSUPP;
372 	}
373 
374 	DBF_DEV_EVENT(DBF_INFO, device,
375 		      "%04X: %04X on real %04X/%02X",
376 		      rdc_data->dev_nr,
377 		      rdc_data->vdev_type,
378 		      rdc_data->rdev_type, rdc_data->rdev_model);
379 
380 	/* terminate all outstanding operations */
381 	mdsk_term_io(device);
382 
383 	/* figure out blocksize of device */
384 	label = (struct vtoc_cms_label *) get_zeroed_page(GFP_KERNEL);
385 	if (label == NULL)  {
386 		DEV_MESSAGE(KERN_WARNING, device, "%s",
387 			    "No memory to allocate initialization request");
388 		return -ENOMEM;
389 	}
390 	rc = 0;
391 	end_block = 0;
392 	/* try all sizes - needed for ECKD devices */
393 	for (bsize = 512; bsize <= PAGE_SIZE; bsize <<= 1) {
394 		mdsk_init_io(device, bsize, 0, &end_block);
395 		memset(&bio, 0, sizeof (struct dasd_diag_bio));
396 		bio.type = MDSK_READ_REQ;
397 		bio.block_number = private->pt_block + 1;
398 		bio.buffer = label;
399 		memset(&private->iob, 0, sizeof (struct dasd_diag_rw_io));
400 		private->iob.dev_nr = rdc_data->dev_nr;
401 		private->iob.key = 0;
402 		private->iob.flags = 0;	/* do synchronous io */
403 		private->iob.block_count = 1;
404 		private->iob.interrupt_params = 0;
405 		private->iob.bio_list = &bio;
406 		private->iob.flaga = DASD_DIAG_FLAGA_DEFAULT;
407 		rc = dia250(&private->iob, RW_BIO);
408 		if (rc == 3) {
409 			DEV_MESSAGE(KERN_WARNING, device, "%s",
410 				"DIAG call failed");
411 			rc = -EOPNOTSUPP;
412 			goto out;
413 		}
414 		mdsk_term_io(device);
415 		if (rc == 0)
416 			break;
417 	}
418 	if (bsize > PAGE_SIZE) {
419 		DEV_MESSAGE(KERN_WARNING, device, "device access failed "
420 			    "(rc=%d)", rc);
421 		rc = -EIO;
422 		goto out;
423 	}
424 	/* check for label block */
425 	if (memcmp(label->label_id, DASD_DIAG_CMS1,
426 		  sizeof(DASD_DIAG_CMS1)) == 0) {
427 		/* get formatted blocksize from label block */
428 		bsize = (unsigned int) label->block_size;
429 		device->blocks = (unsigned long) label->block_count;
430 	} else
431 		device->blocks = end_block;
432 	device->bp_block = bsize;
433 	device->s2b_shift = 0;	/* bits to shift 512 to get a block */
434 	for (sb = 512; sb < bsize; sb = sb << 1)
435 		device->s2b_shift++;
436 	rc = mdsk_init_io(device, device->bp_block, 0, NULL);
437 	if (rc) {
438 		DEV_MESSAGE(KERN_WARNING, device, "DIAG initialization "
439 			"failed (rc=%d)", rc);
440 		rc = -EIO;
441 	} else {
442 		DEV_MESSAGE(KERN_INFO, device,
443 			    "(%ld B/blk): %ldkB",
444 			    (unsigned long) device->bp_block,
445 			    (unsigned long) (device->blocks <<
446 				device->s2b_shift) >> 1);
447 	}
448 out:
449 	free_page((long) label);
450 	return rc;
451 }
452 
453 /* Fill in virtual disk geometry for device. Return zero on success, non-zero
454  * otherwise. */
455 static int
456 dasd_diag_fill_geometry(struct dasd_device *device, struct hd_geometry *geo)
457 {
458 	if (dasd_check_blocksize(device->bp_block) != 0)
459 		return -EINVAL;
460 	geo->cylinders = (device->blocks << device->s2b_shift) >> 10;
461 	geo->heads = 16;
462 	geo->sectors = 128 >> device->s2b_shift;
463 	return 0;
464 }
465 
466 static dasd_era_t
467 dasd_diag_examine_error(struct dasd_ccw_req * cqr, struct irb * stat)
468 {
469 	return dasd_era_fatal;
470 }
471 
472 static dasd_erp_fn_t
473 dasd_diag_erp_action(struct dasd_ccw_req * cqr)
474 {
475 	return dasd_default_erp_action;
476 }
477 
478 static dasd_erp_fn_t
479 dasd_diag_erp_postaction(struct dasd_ccw_req * cqr)
480 {
481 	return dasd_default_erp_postaction;
482 }
483 
484 /* Create DASD request from block device request. Return pointer to new
485  * request on success, ERR_PTR otherwise. */
486 static struct dasd_ccw_req *
487 dasd_diag_build_cp(struct dasd_device * device, struct request *req)
488 {
489 	struct dasd_ccw_req *cqr;
490 	struct dasd_diag_req *dreq;
491 	struct dasd_diag_bio *dbio;
492 	struct bio *bio;
493 	struct bio_vec *bv;
494 	char *dst;
495 	unsigned int count, datasize;
496 	sector_t recid, first_rec, last_rec;
497 	unsigned int blksize, off;
498 	unsigned char rw_cmd;
499 	int i;
500 
501 	if (rq_data_dir(req) == READ)
502 		rw_cmd = MDSK_READ_REQ;
503 	else if (rq_data_dir(req) == WRITE)
504 		rw_cmd = MDSK_WRITE_REQ;
505 	else
506 		return ERR_PTR(-EINVAL);
507 	blksize = device->bp_block;
508 	/* Calculate record id of first and last block. */
509 	first_rec = req->sector >> device->s2b_shift;
510 	last_rec = (req->sector + req->nr_sectors - 1) >> device->s2b_shift;
511 	/* Check struct bio and count the number of blocks for the request. */
512 	count = 0;
513 	rq_for_each_bio(bio, req) {
514 		bio_for_each_segment(bv, bio, i) {
515 			if (bv->bv_len & (blksize - 1))
516 				/* Fba can only do full blocks. */
517 				return ERR_PTR(-EINVAL);
518 			count += bv->bv_len >> (device->s2b_shift + 9);
519 		}
520 	}
521 	/* Paranoia. */
522 	if (count != last_rec - first_rec + 1)
523 		return ERR_PTR(-EINVAL);
524 	/* Build the request */
525 	datasize = sizeof(struct dasd_diag_req) +
526 		count*sizeof(struct dasd_diag_bio);
527 	cqr = dasd_smalloc_request(dasd_diag_discipline.name, 0,
528 				   datasize, device);
529 	if (IS_ERR(cqr))
530 		return cqr;
531 
532 	dreq = (struct dasd_diag_req *) cqr->data;
533 	dreq->block_count = count;
534 	dbio = dreq->bio;
535 	recid = first_rec;
536 	rq_for_each_bio(bio, req) {
537 		bio_for_each_segment(bv, bio, i) {
538 			dst = page_address(bv->bv_page) + bv->bv_offset;
539 			for (off = 0; off < bv->bv_len; off += blksize) {
540 				memset(dbio, 0, sizeof (struct dasd_diag_bio));
541 				dbio->type = rw_cmd;
542 				dbio->block_number = recid + 1;
543 				dbio->buffer = dst;
544 				dbio++;
545 				dst += blksize;
546 				recid++;
547 			}
548 		}
549 	}
550 	cqr->retries = DIAG_MAX_RETRIES;
551 	cqr->buildclk = get_clock();
552 	if (req->flags & REQ_FAILFAST)
553 		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
554 	cqr->device = device;
555 	cqr->expires = DIAG_TIMEOUT;
556 	cqr->status = DASD_CQR_FILLED;
557 	return cqr;
558 }
559 
560 /* Release DASD request. Return non-zero if request was successful, zero
561  * otherwise. */
562 static int
563 dasd_diag_free_cp(struct dasd_ccw_req *cqr, struct request *req)
564 {
565 	int status;
566 
567 	status = cqr->status == DASD_CQR_DONE;
568 	dasd_sfree_request(cqr, cqr->device);
569 	return status;
570 }
571 
572 /* Fill in IOCTL data for device. */
573 static int
574 dasd_diag_fill_info(struct dasd_device * device,
575 		    struct dasd_information2_t * info)
576 {
577 	struct dasd_diag_private *private;
578 
579 	private = (struct dasd_diag_private *) device->private;
580 	info->label_block = (unsigned int) private->pt_block;
581 	info->FBA_layout = 1;
582 	info->format = DASD_FORMAT_LDL;
583 	info->characteristics_size = sizeof (struct dasd_diag_characteristics);
584 	memcpy(info->characteristics,
585 	       &((struct dasd_diag_private *) device->private)->rdc_data,
586 	       sizeof (struct dasd_diag_characteristics));
587 	info->confdata_size = 0;
588 	return 0;
589 }
590 
591 static void
592 dasd_diag_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
593 		     struct irb *stat)
594 {
595 	DEV_MESSAGE(KERN_ERR, device, "%s",
596 		    "dump sense not available for DIAG data");
597 }
598 
599 struct dasd_discipline dasd_diag_discipline = {
600 	.owner = THIS_MODULE,
601 	.name = "DIAG",
602 	.ebcname = "DIAG",
603 	.max_blocks = DIAG_MAX_BLOCKS,
604 	.check_device = dasd_diag_check_device,
605 	.fill_geometry = dasd_diag_fill_geometry,
606 	.start_IO = dasd_start_diag,
607 	.term_IO = dasd_diag_term_IO,
608 	.examine_error = dasd_diag_examine_error,
609 	.erp_action = dasd_diag_erp_action,
610 	.erp_postaction = dasd_diag_erp_postaction,
611 	.build_cp = dasd_diag_build_cp,
612 	.free_cp = dasd_diag_free_cp,
613 	.dump_sense = dasd_diag_dump_sense,
614 	.fill_info = dasd_diag_fill_info,
615 };
616 
617 static int __init
618 dasd_diag_init(void)
619 {
620 	if (!MACHINE_IS_VM) {
621 		MESSAGE_LOG(KERN_INFO,
622 			    "Machine is not VM: %s "
623 			    "discipline not initializing",
624 			    dasd_diag_discipline.name);
625 		return -ENODEV;
626 	}
627 	ASCEBC(dasd_diag_discipline.ebcname, 4);
628 
629 	ctl_set_bit(0, 9);
630 	register_external_interrupt(0x2603, dasd_ext_handler);
631 	dasd_diag_discipline_pointer = &dasd_diag_discipline;
632 	return 0;
633 }
634 
635 static void __exit
636 dasd_diag_cleanup(void)
637 {
638 	unregister_external_interrupt(0x2603, dasd_ext_handler);
639 	ctl_clear_bit(0, 9);
640 	dasd_diag_discipline_pointer = NULL;
641 }
642 
643 module_init(dasd_diag_init);
644 module_exit(dasd_diag_cleanup);
645