xref: /openbmc/linux/drivers/s390/char/tape_core.c (revision 165f2d28)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    basic function of the tape device driver
4  *
5  *  S390 and zSeries version
6  *    Copyright IBM Corp. 2001, 2009
7  *    Author(s): Carsten Otte <cotte@de.ibm.com>
8  *		 Michael Holzheu <holzheu@de.ibm.com>
9  *		 Tuan Ngo-Anh <ngoanh@de.ibm.com>
10  *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
11  *		 Stefan Bader <shbader@de.ibm.com>
12  */
13 
14 #define KMSG_COMPONENT "tape"
15 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
16 
17 #include <linux/module.h>
18 #include <linux/init.h>	     // for kernel parameters
19 #include <linux/kmod.h>	     // for requesting modules
20 #include <linux/spinlock.h>  // for locks
21 #include <linux/vmalloc.h>
22 #include <linux/list.h>
23 #include <linux/slab.h>
24 
25 #include <asm/types.h>	     // for variable types
26 
27 #define TAPE_DBF_AREA	tape_core_dbf
28 
29 #include "tape.h"
30 #include "tape_std.h"
31 
32 #define LONG_BUSY_TIMEOUT 180 /* seconds */
33 
34 static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
35 static void tape_delayed_next_request(struct work_struct *);
36 static void tape_long_busy_timeout(struct timer_list *t);
37 
38 /*
39  * One list to contain all tape devices of all disciplines, so
40  * we can assign the devices to minor numbers of the same major
41  * The list is protected by the rwlock
42  */
43 static LIST_HEAD(tape_device_list);
44 static DEFINE_RWLOCK(tape_device_lock);
45 
46 /*
47  * Pointer to debug area.
48  */
49 debug_info_t *TAPE_DBF_AREA = NULL;
50 EXPORT_SYMBOL(TAPE_DBF_AREA);
51 
52 /*
53  * Printable strings for tape enumerations.
54  */
55 const char *tape_state_verbose[TS_SIZE] =
56 {
57 	[TS_UNUSED]   = "UNUSED",
58 	[TS_IN_USE]   = "IN_USE",
59 	[TS_BLKUSE]   = "BLKUSE",
60 	[TS_INIT]     = "INIT  ",
61 	[TS_NOT_OPER] = "NOT_OP"
62 };
63 
64 const char *tape_op_verbose[TO_SIZE] =
65 {
66 	[TO_BLOCK] = "BLK",	[TO_BSB] = "BSB",
67 	[TO_BSF] = "BSF",	[TO_DSE] = "DSE",
68 	[TO_FSB] = "FSB",	[TO_FSF] = "FSF",
69 	[TO_LBL] = "LBL",	[TO_NOP] = "NOP",
70 	[TO_RBA] = "RBA",	[TO_RBI] = "RBI",
71 	[TO_RFO] = "RFO",	[TO_REW] = "REW",
72 	[TO_RUN] = "RUN",	[TO_WRI] = "WRI",
73 	[TO_WTM] = "WTM",	[TO_MSEN] = "MSN",
74 	[TO_LOAD] = "LOA",	[TO_READ_CONFIG] = "RCF",
75 	[TO_READ_ATTMSG] = "RAT",
76 	[TO_DIS] = "DIS",	[TO_ASSIGN] = "ASS",
77 	[TO_UNASSIGN] = "UAS",  [TO_CRYPT_ON] = "CON",
78 	[TO_CRYPT_OFF] = "COF",	[TO_KEKL_SET] = "KLS",
79 	[TO_KEKL_QUERY] = "KLQ",[TO_RDC] = "RDC",
80 };
81 
82 static int devid_to_int(struct ccw_dev_id *dev_id)
83 {
84 	return dev_id->devno + (dev_id->ssid << 16);
85 }
86 
87 /*
88  * Some channel attached tape specific attributes.
89  *
90  * FIXME: In the future the first_minor and blocksize attribute should be
91  *        replaced by a link to the cdev tree.
92  */
93 static ssize_t
94 tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *buf)
95 {
96 	struct tape_device *tdev;
97 
98 	tdev = dev_get_drvdata(dev);
99 	return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
100 }
101 
102 static
103 DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
104 
105 static ssize_t
106 tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *buf)
107 {
108 	struct tape_device *tdev;
109 
110 	tdev = dev_get_drvdata(dev);
111 	return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
112 }
113 
114 static
115 DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
116 
117 static ssize_t
118 tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
119 {
120 	struct tape_device *tdev;
121 
122 	tdev = dev_get_drvdata(dev);
123 	return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
124 		"OFFLINE" : tape_state_verbose[tdev->tape_state]);
125 }
126 
127 static
128 DEVICE_ATTR(state, 0444, tape_state_show, NULL);
129 
130 static ssize_t
131 tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf)
132 {
133 	struct tape_device *tdev;
134 	ssize_t rc;
135 
136 	tdev = dev_get_drvdata(dev);
137 	if (tdev->first_minor < 0)
138 		return scnprintf(buf, PAGE_SIZE, "N/A\n");
139 
140 	spin_lock_irq(get_ccwdev_lock(tdev->cdev));
141 	if (list_empty(&tdev->req_queue))
142 		rc = scnprintf(buf, PAGE_SIZE, "---\n");
143 	else {
144 		struct tape_request *req;
145 
146 		req = list_entry(tdev->req_queue.next, struct tape_request,
147 			list);
148 		rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
149 	}
150 	spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
151 	return rc;
152 }
153 
154 static
155 DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
156 
157 static ssize_t
158 tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf)
159 {
160 	struct tape_device *tdev;
161 
162 	tdev = dev_get_drvdata(dev);
163 
164 	return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
165 }
166 
167 static
168 DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
169 
170 static struct attribute *tape_attrs[] = {
171 	&dev_attr_medium_state.attr,
172 	&dev_attr_first_minor.attr,
173 	&dev_attr_state.attr,
174 	&dev_attr_operation.attr,
175 	&dev_attr_blocksize.attr,
176 	NULL
177 };
178 
179 static const struct attribute_group tape_attr_group = {
180 	.attrs = tape_attrs,
181 };
182 
183 /*
184  * Tape state functions
185  */
186 void
187 tape_state_set(struct tape_device *device, enum tape_state newstate)
188 {
189 	const char *str;
190 
191 	if (device->tape_state == TS_NOT_OPER) {
192 		DBF_EVENT(3, "ts_set err: not oper\n");
193 		return;
194 	}
195 	DBF_EVENT(4, "ts. dev:	%x\n", device->first_minor);
196 	DBF_EVENT(4, "old ts:\t\n");
197 	if (device->tape_state < TS_SIZE && device->tape_state >=0 )
198 		str = tape_state_verbose[device->tape_state];
199 	else
200 		str = "UNKNOWN TS";
201 	DBF_EVENT(4, "%s\n", str);
202 	DBF_EVENT(4, "new ts:\t\n");
203 	if (newstate < TS_SIZE && newstate >= 0)
204 		str = tape_state_verbose[newstate];
205 	else
206 		str = "UNKNOWN TS";
207 	DBF_EVENT(4, "%s\n", str);
208 	device->tape_state = newstate;
209 	wake_up(&device->state_change_wq);
210 }
211 
212 struct tape_med_state_work_data {
213 	struct tape_device *device;
214 	enum tape_medium_state state;
215 	struct work_struct  work;
216 };
217 
218 static void
219 tape_med_state_work_handler(struct work_struct *work)
220 {
221 	static char env_state_loaded[] = "MEDIUM_STATE=LOADED";
222 	static char env_state_unloaded[] = "MEDIUM_STATE=UNLOADED";
223 	struct tape_med_state_work_data *p =
224 		container_of(work, struct tape_med_state_work_data, work);
225 	struct tape_device *device = p->device;
226 	char *envp[] = { NULL, NULL };
227 
228 	switch (p->state) {
229 	case MS_UNLOADED:
230 		pr_info("%s: The tape cartridge has been successfully "
231 			"unloaded\n", dev_name(&device->cdev->dev));
232 		envp[0] = env_state_unloaded;
233 		kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
234 		break;
235 	case MS_LOADED:
236 		pr_info("%s: A tape cartridge has been mounted\n",
237 			dev_name(&device->cdev->dev));
238 		envp[0] = env_state_loaded;
239 		kobject_uevent_env(&device->cdev->dev.kobj, KOBJ_CHANGE, envp);
240 		break;
241 	default:
242 		break;
243 	}
244 	tape_put_device(device);
245 	kfree(p);
246 }
247 
248 static void
249 tape_med_state_work(struct tape_device *device, enum tape_medium_state state)
250 {
251 	struct tape_med_state_work_data *p;
252 
253 	p = kzalloc(sizeof(*p), GFP_ATOMIC);
254 	if (p) {
255 		INIT_WORK(&p->work, tape_med_state_work_handler);
256 		p->device = tape_get_device(device);
257 		p->state = state;
258 		schedule_work(&p->work);
259 	}
260 }
261 
262 void
263 tape_med_state_set(struct tape_device *device, enum tape_medium_state newstate)
264 {
265 	enum tape_medium_state oldstate;
266 
267 	oldstate = device->medium_state;
268 	if (oldstate == newstate)
269 		return;
270 	device->medium_state = newstate;
271 	switch(newstate){
272 	case MS_UNLOADED:
273 		device->tape_generic_status |= GMT_DR_OPEN(~0);
274 		if (oldstate == MS_LOADED)
275 			tape_med_state_work(device, MS_UNLOADED);
276 		break;
277 	case MS_LOADED:
278 		device->tape_generic_status &= ~GMT_DR_OPEN(~0);
279 		if (oldstate == MS_UNLOADED)
280 			tape_med_state_work(device, MS_LOADED);
281 		break;
282 	default:
283 		break;
284 	}
285 	wake_up(&device->state_change_wq);
286 }
287 
288 /*
289  * Stop running ccw. Has to be called with the device lock held.
290  */
291 static int
292 __tape_cancel_io(struct tape_device *device, struct tape_request *request)
293 {
294 	int retries;
295 	int rc;
296 
297 	/* Check if interrupt has already been processed */
298 	if (request->callback == NULL)
299 		return 0;
300 
301 	rc = 0;
302 	for (retries = 0; retries < 5; retries++) {
303 		rc = ccw_device_clear(device->cdev, (long) request);
304 
305 		switch (rc) {
306 			case 0:
307 				request->status	= TAPE_REQUEST_DONE;
308 				return 0;
309 			case -EBUSY:
310 				request->status	= TAPE_REQUEST_CANCEL;
311 				schedule_delayed_work(&device->tape_dnr, 0);
312 				return 0;
313 			case -ENODEV:
314 				DBF_EXCEPTION(2, "device gone, retry\n");
315 				break;
316 			case -EIO:
317 				DBF_EXCEPTION(2, "I/O error, retry\n");
318 				break;
319 			default:
320 				BUG();
321 		}
322 	}
323 
324 	return rc;
325 }
326 
327 /*
328  * Add device into the sorted list, giving it the first
329  * available minor number.
330  */
331 static int
332 tape_assign_minor(struct tape_device *device)
333 {
334 	struct tape_device *tmp;
335 	int minor;
336 
337 	minor = 0;
338 	write_lock(&tape_device_lock);
339 	list_for_each_entry(tmp, &tape_device_list, node) {
340 		if (minor < tmp->first_minor)
341 			break;
342 		minor += TAPE_MINORS_PER_DEV;
343 	}
344 	if (minor >= 256) {
345 		write_unlock(&tape_device_lock);
346 		return -ENODEV;
347 	}
348 	device->first_minor = minor;
349 	list_add_tail(&device->node, &tmp->node);
350 	write_unlock(&tape_device_lock);
351 	return 0;
352 }
353 
354 /* remove device from the list */
355 static void
356 tape_remove_minor(struct tape_device *device)
357 {
358 	write_lock(&tape_device_lock);
359 	list_del_init(&device->node);
360 	device->first_minor = -1;
361 	write_unlock(&tape_device_lock);
362 }
363 
364 /*
365  * Set a device online.
366  *
367  * This function is called by the common I/O layer to move a device from the
368  * detected but offline into the online state.
369  * If we return an error (RC < 0) the device remains in the offline state. This
370  * can happen if the device is assigned somewhere else, for example.
371  */
372 int
373 tape_generic_online(struct tape_device *device,
374 		   struct tape_discipline *discipline)
375 {
376 	int rc;
377 
378 	DBF_LH(6, "tape_enable_device(%p, %p)\n", device, discipline);
379 
380 	if (device->tape_state != TS_INIT) {
381 		DBF_LH(3, "Tapestate not INIT (%d)\n", device->tape_state);
382 		return -EINVAL;
383 	}
384 
385 	timer_setup(&device->lb_timeout, tape_long_busy_timeout, 0);
386 
387 	/* Let the discipline have a go at the device. */
388 	device->discipline = discipline;
389 	if (!try_module_get(discipline->owner)) {
390 		return -EINVAL;
391 	}
392 
393 	rc = discipline->setup_device(device);
394 	if (rc)
395 		goto out;
396 	rc = tape_assign_minor(device);
397 	if (rc)
398 		goto out_discipline;
399 
400 	rc = tapechar_setup_device(device);
401 	if (rc)
402 		goto out_minor;
403 
404 	tape_state_set(device, TS_UNUSED);
405 
406 	DBF_LH(3, "(%08x): Drive set online\n", device->cdev_id);
407 
408 	return 0;
409 
410 out_minor:
411 	tape_remove_minor(device);
412 out_discipline:
413 	device->discipline->cleanup_device(device);
414 	device->discipline = NULL;
415 out:
416 	module_put(discipline->owner);
417 	return rc;
418 }
419 
420 static void
421 tape_cleanup_device(struct tape_device *device)
422 {
423 	tapechar_cleanup_device(device);
424 	device->discipline->cleanup_device(device);
425 	module_put(device->discipline->owner);
426 	tape_remove_minor(device);
427 	tape_med_state_set(device, MS_UNKNOWN);
428 }
429 
430 /*
431  * Suspend device.
432  *
433  * Called by the common I/O layer if the drive should be suspended on user
434  * request. We refuse to suspend if the device is loaded or in use for the
435  * following reason:
436  * While the Linux guest is suspended, it might be logged off which causes
437  * devices to be detached. Tape devices are automatically rewound and unloaded
438  * during DETACH processing (unless the tape device was attached with the
439  * NOASSIGN or MULTIUSER option). After rewind/unload, there is no way to
440  * resume the original state of the tape device, since we would need to
441  * manually re-load the cartridge which was active at suspend time.
442  */
443 int tape_generic_pm_suspend(struct ccw_device *cdev)
444 {
445 	struct tape_device *device;
446 
447 	device = dev_get_drvdata(&cdev->dev);
448 	if (!device) {
449 		return -ENODEV;
450 	}
451 
452 	DBF_LH(3, "(%08x): tape_generic_pm_suspend(%p)\n",
453 		device->cdev_id, device);
454 
455 	if (device->medium_state != MS_UNLOADED) {
456 		pr_err("A cartridge is loaded in tape device %s, "
457 		       "refusing to suspend\n", dev_name(&cdev->dev));
458 		return -EBUSY;
459 	}
460 
461 	spin_lock_irq(get_ccwdev_lock(device->cdev));
462 	switch (device->tape_state) {
463 		case TS_INIT:
464 		case TS_NOT_OPER:
465 		case TS_UNUSED:
466 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
467 			break;
468 		default:
469 			pr_err("Tape device %s is busy, refusing to "
470 			       "suspend\n", dev_name(&cdev->dev));
471 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
472 			return -EBUSY;
473 	}
474 
475 	DBF_LH(3, "(%08x): Drive suspended.\n", device->cdev_id);
476 	return 0;
477 }
478 
479 /*
480  * Set device offline.
481  *
482  * Called by the common I/O layer if the drive should set offline on user
483  * request. We may prevent this by returning an error.
484  * Manual offline is only allowed while the drive is not in use.
485  */
486 int
487 tape_generic_offline(struct ccw_device *cdev)
488 {
489 	struct tape_device *device;
490 
491 	device = dev_get_drvdata(&cdev->dev);
492 	if (!device) {
493 		return -ENODEV;
494 	}
495 
496 	DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
497 		device->cdev_id, device);
498 
499 	spin_lock_irq(get_ccwdev_lock(device->cdev));
500 	switch (device->tape_state) {
501 		case TS_INIT:
502 		case TS_NOT_OPER:
503 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
504 			break;
505 		case TS_UNUSED:
506 			tape_state_set(device, TS_INIT);
507 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
508 			tape_cleanup_device(device);
509 			break;
510 		default:
511 			DBF_EVENT(3, "(%08x): Set offline failed "
512 				"- drive in use.\n",
513 				device->cdev_id);
514 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
515 			return -EBUSY;
516 	}
517 
518 	DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
519 	return 0;
520 }
521 
522 /*
523  * Allocate memory for a new device structure.
524  */
525 static struct tape_device *
526 tape_alloc_device(void)
527 {
528 	struct tape_device *device;
529 
530 	device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
531 	if (device == NULL) {
532 		DBF_EXCEPTION(2, "ti:no mem\n");
533 		return ERR_PTR(-ENOMEM);
534 	}
535 	device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
536 	if (device->modeset_byte == NULL) {
537 		DBF_EXCEPTION(2, "ti:no mem\n");
538 		kfree(device);
539 		return ERR_PTR(-ENOMEM);
540 	}
541 	mutex_init(&device->mutex);
542 	INIT_LIST_HEAD(&device->req_queue);
543 	INIT_LIST_HEAD(&device->node);
544 	init_waitqueue_head(&device->state_change_wq);
545 	init_waitqueue_head(&device->wait_queue);
546 	device->tape_state = TS_INIT;
547 	device->medium_state = MS_UNKNOWN;
548 	*device->modeset_byte = 0;
549 	device->first_minor = -1;
550 	atomic_set(&device->ref_count, 1);
551 	INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
552 
553 	return device;
554 }
555 
556 /*
557  * Get a reference to an existing device structure. This will automatically
558  * increment the reference count.
559  */
560 struct tape_device *
561 tape_get_device(struct tape_device *device)
562 {
563 	int count;
564 
565 	count = atomic_inc_return(&device->ref_count);
566 	DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
567 	return device;
568 }
569 
570 /*
571  * Decrease the reference counter of a devices structure. If the
572  * reference counter reaches zero free the device structure.
573  * The function returns a NULL pointer to be used by the caller
574  * for clearing reference pointers.
575  */
576 void
577 tape_put_device(struct tape_device *device)
578 {
579 	int count;
580 
581 	count = atomic_dec_return(&device->ref_count);
582 	DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
583 	BUG_ON(count < 0);
584 	if (count == 0) {
585 		kfree(device->modeset_byte);
586 		kfree(device);
587 	}
588 }
589 
590 /*
591  * Find tape device by a device index.
592  */
593 struct tape_device *
594 tape_find_device(int devindex)
595 {
596 	struct tape_device *device, *tmp;
597 
598 	device = ERR_PTR(-ENODEV);
599 	read_lock(&tape_device_lock);
600 	list_for_each_entry(tmp, &tape_device_list, node) {
601 		if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
602 			device = tape_get_device(tmp);
603 			break;
604 		}
605 	}
606 	read_unlock(&tape_device_lock);
607 	return device;
608 }
609 
610 /*
611  * Driverfs tape probe function.
612  */
613 int
614 tape_generic_probe(struct ccw_device *cdev)
615 {
616 	struct tape_device *device;
617 	int ret;
618 	struct ccw_dev_id dev_id;
619 
620 	device = tape_alloc_device();
621 	if (IS_ERR(device))
622 		return -ENODEV;
623 	ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
624 				     CCWDEV_DO_MULTIPATH);
625 	ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
626 	if (ret) {
627 		tape_put_device(device);
628 		return ret;
629 	}
630 	dev_set_drvdata(&cdev->dev, device);
631 	cdev->handler = __tape_do_irq;
632 	device->cdev = cdev;
633 	ccw_device_get_id(cdev, &dev_id);
634 	device->cdev_id = devid_to_int(&dev_id);
635 	return ret;
636 }
637 
638 static void
639 __tape_discard_requests(struct tape_device *device)
640 {
641 	struct tape_request *	request;
642 	struct list_head *	l, *n;
643 
644 	list_for_each_safe(l, n, &device->req_queue) {
645 		request = list_entry(l, struct tape_request, list);
646 		if (request->status == TAPE_REQUEST_IN_IO)
647 			request->status = TAPE_REQUEST_DONE;
648 		list_del(&request->list);
649 
650 		/* Decrease ref_count for removed request. */
651 		request->device = NULL;
652 		tape_put_device(device);
653 		request->rc = -EIO;
654 		if (request->callback != NULL)
655 			request->callback(request, request->callback_data);
656 	}
657 }
658 
659 /*
660  * Driverfs tape remove function.
661  *
662  * This function is called whenever the common I/O layer detects the device
663  * gone. This can happen at any time and we cannot refuse.
664  */
665 void
666 tape_generic_remove(struct ccw_device *cdev)
667 {
668 	struct tape_device *	device;
669 
670 	device = dev_get_drvdata(&cdev->dev);
671 	if (!device) {
672 		return;
673 	}
674 	DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
675 
676 	spin_lock_irq(get_ccwdev_lock(device->cdev));
677 	switch (device->tape_state) {
678 		case TS_INIT:
679 			tape_state_set(device, TS_NOT_OPER);
680 			fallthrough;
681 		case TS_NOT_OPER:
682 			/*
683 			 * Nothing to do.
684 			 */
685 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
686 			break;
687 		case TS_UNUSED:
688 			/*
689 			 * Need only to release the device.
690 			 */
691 			tape_state_set(device, TS_NOT_OPER);
692 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
693 			tape_cleanup_device(device);
694 			break;
695 		default:
696 			/*
697 			 * There may be requests on the queue. We will not get
698 			 * an interrupt for a request that was running. So we
699 			 * just post them all as I/O errors.
700 			 */
701 			DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
702 				device->cdev_id);
703 			pr_warn("%s: A tape unit was detached while in use\n",
704 				dev_name(&device->cdev->dev));
705 			tape_state_set(device, TS_NOT_OPER);
706 			__tape_discard_requests(device);
707 			spin_unlock_irq(get_ccwdev_lock(device->cdev));
708 			tape_cleanup_device(device);
709 	}
710 
711 	device = dev_get_drvdata(&cdev->dev);
712 	if (device) {
713 		sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
714 		dev_set_drvdata(&cdev->dev, NULL);
715 		tape_put_device(device);
716 	}
717 }
718 
719 /*
720  * Allocate a new tape ccw request
721  */
722 struct tape_request *
723 tape_alloc_request(int cplength, int datasize)
724 {
725 	struct tape_request *request;
726 
727 	BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
728 
729 	DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
730 
731 	request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
732 	if (request == NULL) {
733 		DBF_EXCEPTION(1, "cqra nomem\n");
734 		return ERR_PTR(-ENOMEM);
735 	}
736 	/* allocate channel program */
737 	if (cplength > 0) {
738 		request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
739 					  GFP_ATOMIC | GFP_DMA);
740 		if (request->cpaddr == NULL) {
741 			DBF_EXCEPTION(1, "cqra nomem\n");
742 			kfree(request);
743 			return ERR_PTR(-ENOMEM);
744 		}
745 	}
746 	/* alloc small kernel buffer */
747 	if (datasize > 0) {
748 		request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
749 		if (request->cpdata == NULL) {
750 			DBF_EXCEPTION(1, "cqra nomem\n");
751 			kfree(request->cpaddr);
752 			kfree(request);
753 			return ERR_PTR(-ENOMEM);
754 		}
755 	}
756 	DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
757 		request->cpdata);
758 
759 	return request;
760 }
761 
762 /*
763  * Free tape ccw request
764  */
765 void
766 tape_free_request (struct tape_request * request)
767 {
768 	DBF_LH(6, "Free request %p\n", request);
769 
770 	if (request->device)
771 		tape_put_device(request->device);
772 	kfree(request->cpdata);
773 	kfree(request->cpaddr);
774 	kfree(request);
775 }
776 
777 static int
778 __tape_start_io(struct tape_device *device, struct tape_request *request)
779 {
780 	int rc;
781 
782 	rc = ccw_device_start(
783 		device->cdev,
784 		request->cpaddr,
785 		(unsigned long) request,
786 		0x00,
787 		request->options
788 	);
789 	if (rc == 0) {
790 		request->status = TAPE_REQUEST_IN_IO;
791 	} else if (rc == -EBUSY) {
792 		/* The common I/O subsystem is currently busy. Retry later. */
793 		request->status = TAPE_REQUEST_QUEUED;
794 		schedule_delayed_work(&device->tape_dnr, 0);
795 		rc = 0;
796 	} else {
797 		/* Start failed. Remove request and indicate failure. */
798 		DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
799 	}
800 	return rc;
801 }
802 
803 static void
804 __tape_start_next_request(struct tape_device *device)
805 {
806 	struct list_head *l, *n;
807 	struct tape_request *request;
808 	int rc;
809 
810 	DBF_LH(6, "__tape_start_next_request(%p)\n", device);
811 	/*
812 	 * Try to start each request on request queue until one is
813 	 * started successful.
814 	 */
815 	list_for_each_safe(l, n, &device->req_queue) {
816 		request = list_entry(l, struct tape_request, list);
817 
818 		/*
819 		 * Avoid race condition if bottom-half was triggered more than
820 		 * once.
821 		 */
822 		if (request->status == TAPE_REQUEST_IN_IO)
823 			return;
824 		/*
825 		 * Request has already been stopped. We have to wait until
826 		 * the request is removed from the queue in the interrupt
827 		 * handling.
828 		 */
829 		if (request->status == TAPE_REQUEST_DONE)
830 			return;
831 
832 		/*
833 		 * We wanted to cancel the request but the common I/O layer
834 		 * was busy at that time. This can only happen if this
835 		 * function is called by delayed_next_request.
836 		 * Otherwise we start the next request on the queue.
837 		 */
838 		if (request->status == TAPE_REQUEST_CANCEL) {
839 			rc = __tape_cancel_io(device, request);
840 		} else {
841 			rc = __tape_start_io(device, request);
842 		}
843 		if (rc == 0)
844 			return;
845 
846 		/* Set ending status. */
847 		request->rc = rc;
848 		request->status = TAPE_REQUEST_DONE;
849 
850 		/* Remove from request queue. */
851 		list_del(&request->list);
852 
853 		/* Do callback. */
854 		if (request->callback != NULL)
855 			request->callback(request, request->callback_data);
856 	}
857 }
858 
859 static void
860 tape_delayed_next_request(struct work_struct *work)
861 {
862 	struct tape_device *device =
863 		container_of(work, struct tape_device, tape_dnr.work);
864 
865 	DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
866 	spin_lock_irq(get_ccwdev_lock(device->cdev));
867 	__tape_start_next_request(device);
868 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
869 }
870 
871 static void tape_long_busy_timeout(struct timer_list *t)
872 {
873 	struct tape_device *device = from_timer(device, t, lb_timeout);
874 	struct tape_request *request;
875 
876 	spin_lock_irq(get_ccwdev_lock(device->cdev));
877 	request = list_entry(device->req_queue.next, struct tape_request, list);
878 	BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
879 	DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
880 	__tape_start_next_request(device);
881 	tape_put_device(device);
882 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
883 }
884 
885 static void
886 __tape_end_request(
887 	struct tape_device *	device,
888 	struct tape_request *	request,
889 	int			rc)
890 {
891 	DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
892 	if (request) {
893 		request->rc = rc;
894 		request->status = TAPE_REQUEST_DONE;
895 
896 		/* Remove from request queue. */
897 		list_del(&request->list);
898 
899 		/* Do callback. */
900 		if (request->callback != NULL)
901 			request->callback(request, request->callback_data);
902 	}
903 
904 	/* Start next request. */
905 	if (!list_empty(&device->req_queue))
906 		__tape_start_next_request(device);
907 }
908 
909 /*
910  * Write sense data to dbf
911  */
912 void
913 tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
914 		    struct irb *irb)
915 {
916 	unsigned int *sptr;
917 	const char* op;
918 
919 	if (request != NULL)
920 		op = tape_op_verbose[request->op];
921 	else
922 		op = "---";
923 	DBF_EVENT(3, "DSTAT : %02x   CSTAT: %02x\n",
924 		  irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
925 	DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
926 	sptr = (unsigned int *) irb->ecw;
927 	DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
928 	DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
929 	DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
930 	DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
931 }
932 
933 /*
934  * I/O helper function. Adds the request to the request queue
935  * and starts it if the tape is idle. Has to be called with
936  * the device lock held.
937  */
938 static int
939 __tape_start_request(struct tape_device *device, struct tape_request *request)
940 {
941 	int rc;
942 
943 	switch (request->op) {
944 		case TO_MSEN:
945 		case TO_ASSIGN:
946 		case TO_UNASSIGN:
947 		case TO_READ_ATTMSG:
948 		case TO_RDC:
949 			if (device->tape_state == TS_INIT)
950 				break;
951 			if (device->tape_state == TS_UNUSED)
952 				break;
953 			fallthrough;
954 		default:
955 			if (device->tape_state == TS_BLKUSE)
956 				break;
957 			if (device->tape_state != TS_IN_USE)
958 				return -ENODEV;
959 	}
960 
961 	/* Increase use count of device for the added request. */
962 	request->device = tape_get_device(device);
963 
964 	if (list_empty(&device->req_queue)) {
965 		/* No other requests are on the queue. Start this one. */
966 		rc = __tape_start_io(device, request);
967 		if (rc)
968 			return rc;
969 
970 		DBF_LH(5, "Request %p added for execution.\n", request);
971 		list_add(&request->list, &device->req_queue);
972 	} else {
973 		DBF_LH(5, "Request %p add to queue.\n", request);
974 		request->status = TAPE_REQUEST_QUEUED;
975 		list_add_tail(&request->list, &device->req_queue);
976 	}
977 	return 0;
978 }
979 
980 /*
981  * Add the request to the request queue, try to start it if the
982  * tape is idle. Return without waiting for end of i/o.
983  */
984 int
985 tape_do_io_async(struct tape_device *device, struct tape_request *request)
986 {
987 	int rc;
988 
989 	DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
990 
991 	spin_lock_irq(get_ccwdev_lock(device->cdev));
992 	/* Add request to request queue and try to start it. */
993 	rc = __tape_start_request(device, request);
994 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
995 	return rc;
996 }
997 
998 /*
999  * tape_do_io/__tape_wake_up
1000  * Add the request to the request queue, try to start it if the
1001  * tape is idle and wait uninterruptible for its completion.
1002  */
1003 static void
1004 __tape_wake_up(struct tape_request *request, void *data)
1005 {
1006 	request->callback = NULL;
1007 	wake_up((wait_queue_head_t *) data);
1008 }
1009 
1010 int
1011 tape_do_io(struct tape_device *device, struct tape_request *request)
1012 {
1013 	int rc;
1014 
1015 	spin_lock_irq(get_ccwdev_lock(device->cdev));
1016 	/* Setup callback */
1017 	request->callback = __tape_wake_up;
1018 	request->callback_data = &device->wait_queue;
1019 	/* Add request to request queue and try to start it. */
1020 	rc = __tape_start_request(device, request);
1021 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1022 	if (rc)
1023 		return rc;
1024 	/* Request added to the queue. Wait for its completion. */
1025 	wait_event(device->wait_queue, (request->callback == NULL));
1026 	/* Get rc from request */
1027 	return request->rc;
1028 }
1029 
1030 /*
1031  * tape_do_io_interruptible/__tape_wake_up_interruptible
1032  * Add the request to the request queue, try to start it if the
1033  * tape is idle and wait uninterruptible for its completion.
1034  */
1035 static void
1036 __tape_wake_up_interruptible(struct tape_request *request, void *data)
1037 {
1038 	request->callback = NULL;
1039 	wake_up_interruptible((wait_queue_head_t *) data);
1040 }
1041 
1042 int
1043 tape_do_io_interruptible(struct tape_device *device,
1044 			 struct tape_request *request)
1045 {
1046 	int rc;
1047 
1048 	spin_lock_irq(get_ccwdev_lock(device->cdev));
1049 	/* Setup callback */
1050 	request->callback = __tape_wake_up_interruptible;
1051 	request->callback_data = &device->wait_queue;
1052 	rc = __tape_start_request(device, request);
1053 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1054 	if (rc)
1055 		return rc;
1056 	/* Request added to the queue. Wait for its completion. */
1057 	rc = wait_event_interruptible(device->wait_queue,
1058 				      (request->callback == NULL));
1059 	if (rc != -ERESTARTSYS)
1060 		/* Request finished normally. */
1061 		return request->rc;
1062 
1063 	/* Interrupted by a signal. We have to stop the current request. */
1064 	spin_lock_irq(get_ccwdev_lock(device->cdev));
1065 	rc = __tape_cancel_io(device, request);
1066 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1067 	if (rc == 0) {
1068 		/* Wait for the interrupt that acknowledges the halt. */
1069 		do {
1070 			rc = wait_event_interruptible(
1071 				device->wait_queue,
1072 				(request->callback == NULL)
1073 			);
1074 		} while (rc == -ERESTARTSYS);
1075 
1076 		DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1077 		rc = -ERESTARTSYS;
1078 	}
1079 	return rc;
1080 }
1081 
1082 /*
1083  * Stop running ccw.
1084  */
1085 int
1086 tape_cancel_io(struct tape_device *device, struct tape_request *request)
1087 {
1088 	int rc;
1089 
1090 	spin_lock_irq(get_ccwdev_lock(device->cdev));
1091 	rc = __tape_cancel_io(device, request);
1092 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1093 	return rc;
1094 }
1095 
1096 /*
1097  * Tape interrupt routine, called from the ccw_device layer
1098  */
1099 static void
1100 __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1101 {
1102 	struct tape_device *device;
1103 	struct tape_request *request;
1104 	int rc;
1105 
1106 	device = dev_get_drvdata(&cdev->dev);
1107 	if (device == NULL) {
1108 		return;
1109 	}
1110 	request = (struct tape_request *) intparm;
1111 
1112 	DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1113 
1114 	/* On special conditions irb is an error pointer */
1115 	if (IS_ERR(irb)) {
1116 		/* FIXME: What to do with the request? */
1117 		switch (PTR_ERR(irb)) {
1118 			case -ETIMEDOUT:
1119 				DBF_LH(1, "(%08x): Request timed out\n",
1120 				       device->cdev_id);
1121 				fallthrough;
1122 			case -EIO:
1123 				__tape_end_request(device, request, -EIO);
1124 				break;
1125 			default:
1126 				DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
1127 				       device->cdev_id,	PTR_ERR(irb));
1128 		}
1129 		return;
1130 	}
1131 
1132 	/*
1133 	 * If the condition code is not zero and the start function bit is
1134 	 * still set, this is an deferred error and the last start I/O did
1135 	 * not succeed. At this point the condition that caused the deferred
1136 	 * error might still apply. So we just schedule the request to be
1137 	 * started later.
1138 	 */
1139 	if (irb->scsw.cmd.cc != 0 &&
1140 	    (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1141 	    (request->status == TAPE_REQUEST_IN_IO)) {
1142 		DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1143 			device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1144 		request->status = TAPE_REQUEST_QUEUED;
1145 		schedule_delayed_work(&device->tape_dnr, HZ);
1146 		return;
1147 	}
1148 
1149 	/* May be an unsolicited irq */
1150 	if(request != NULL)
1151 		request->rescnt = irb->scsw.cmd.count;
1152 	else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1153 		 !list_empty(&device->req_queue)) {
1154 		/* Not Ready to Ready after long busy ? */
1155 		struct tape_request *req;
1156 		req = list_entry(device->req_queue.next,
1157 				 struct tape_request, list);
1158 		if (req->status == TAPE_REQUEST_LONG_BUSY) {
1159 			DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1160 			if (del_timer(&device->lb_timeout)) {
1161 				tape_put_device(device);
1162 				__tape_start_next_request(device);
1163 			}
1164 			return;
1165 		}
1166 	}
1167 	if (irb->scsw.cmd.dstat != 0x0c) {
1168 		/* Set the 'ONLINE' flag depending on sense byte 1 */
1169 		if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1170 			device->tape_generic_status |= GMT_ONLINE(~0);
1171 		else
1172 			device->tape_generic_status &= ~GMT_ONLINE(~0);
1173 
1174 		/*
1175 		 * Any request that does not come back with channel end
1176 		 * and device end is unusual. Log the sense data.
1177 		 */
1178 		DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1179 		tape_dump_sense_dbf(device, request, irb);
1180 	} else {
1181 		/* Upon normal completion the device _is_ online */
1182 		device->tape_generic_status |= GMT_ONLINE(~0);
1183 	}
1184 	if (device->tape_state == TS_NOT_OPER) {
1185 		DBF_EVENT(6, "tape:device is not operational\n");
1186 		return;
1187 	}
1188 
1189 	/*
1190 	 * Request that were canceled still come back with an interrupt.
1191 	 * To detect these request the state will be set to TAPE_REQUEST_DONE.
1192 	 */
1193 	if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1194 		__tape_end_request(device, request, -EIO);
1195 		return;
1196 	}
1197 
1198 	rc = device->discipline->irq(device, request, irb);
1199 	/*
1200 	 * rc < 0 : request finished unsuccessfully.
1201 	 * rc == TAPE_IO_SUCCESS: request finished successfully.
1202 	 * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1203 	 * rc == TAPE_IO_RETRY: request finished but needs another go.
1204 	 * rc == TAPE_IO_STOP: request needs to get terminated.
1205 	 */
1206 	switch (rc) {
1207 		case TAPE_IO_SUCCESS:
1208 			/* Upon normal completion the device _is_ online */
1209 			device->tape_generic_status |= GMT_ONLINE(~0);
1210 			__tape_end_request(device, request, rc);
1211 			break;
1212 		case TAPE_IO_PENDING:
1213 			break;
1214 		case TAPE_IO_LONG_BUSY:
1215 			device->lb_timeout.expires = jiffies +
1216 				LONG_BUSY_TIMEOUT * HZ;
1217 			DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1218 			add_timer(&device->lb_timeout);
1219 			request->status = TAPE_REQUEST_LONG_BUSY;
1220 			break;
1221 		case TAPE_IO_RETRY:
1222 			rc = __tape_start_io(device, request);
1223 			if (rc)
1224 				__tape_end_request(device, request, rc);
1225 			break;
1226 		case TAPE_IO_STOP:
1227 			rc = __tape_cancel_io(device, request);
1228 			if (rc)
1229 				__tape_end_request(device, request, rc);
1230 			break;
1231 		default:
1232 			if (rc > 0) {
1233 				DBF_EVENT(6, "xunknownrc\n");
1234 				__tape_end_request(device, request, -EIO);
1235 			} else {
1236 				__tape_end_request(device, request, rc);
1237 			}
1238 			break;
1239 	}
1240 }
1241 
1242 /*
1243  * Tape device open function used by tape_char frontend.
1244  */
1245 int
1246 tape_open(struct tape_device *device)
1247 {
1248 	int rc;
1249 
1250 	spin_lock_irq(get_ccwdev_lock(device->cdev));
1251 	if (device->tape_state == TS_NOT_OPER) {
1252 		DBF_EVENT(6, "TAPE:nodev\n");
1253 		rc = -ENODEV;
1254 	} else if (device->tape_state == TS_IN_USE) {
1255 		DBF_EVENT(6, "TAPE:dbusy\n");
1256 		rc = -EBUSY;
1257 	} else if (device->tape_state == TS_BLKUSE) {
1258 		DBF_EVENT(6, "TAPE:dbusy\n");
1259 		rc = -EBUSY;
1260 	} else if (device->discipline != NULL &&
1261 		   !try_module_get(device->discipline->owner)) {
1262 		DBF_EVENT(6, "TAPE:nodisc\n");
1263 		rc = -ENODEV;
1264 	} else {
1265 		tape_state_set(device, TS_IN_USE);
1266 		rc = 0;
1267 	}
1268 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1269 	return rc;
1270 }
1271 
1272 /*
1273  * Tape device release function used by tape_char frontend.
1274  */
1275 int
1276 tape_release(struct tape_device *device)
1277 {
1278 	spin_lock_irq(get_ccwdev_lock(device->cdev));
1279 	if (device->tape_state == TS_IN_USE)
1280 		tape_state_set(device, TS_UNUSED);
1281 	module_put(device->discipline->owner);
1282 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1283 	return 0;
1284 }
1285 
1286 /*
1287  * Execute a magnetic tape command a number of times.
1288  */
1289 int
1290 tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1291 {
1292 	tape_mtop_fn fn;
1293 	int rc;
1294 
1295 	DBF_EVENT(6, "TAPE:mtio\n");
1296 	DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1297 	DBF_EVENT(6, "TAPE:arg:	 %x\n", mt_count);
1298 
1299 	if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1300 		return -EINVAL;
1301 	fn = device->discipline->mtop_array[mt_op];
1302 	if (fn == NULL)
1303 		return -EINVAL;
1304 
1305 	/* We assume that the backends can handle count up to 500. */
1306 	if (mt_op == MTBSR  || mt_op == MTFSR  || mt_op == MTFSF  ||
1307 	    mt_op == MTBSF  || mt_op == MTFSFM || mt_op == MTBSFM) {
1308 		rc = 0;
1309 		for (; mt_count > 500; mt_count -= 500)
1310 			if ((rc = fn(device, 500)) != 0)
1311 				break;
1312 		if (rc == 0)
1313 			rc = fn(device, mt_count);
1314 	} else
1315 		rc = fn(device, mt_count);
1316 	return rc;
1317 
1318 }
1319 
1320 /*
1321  * Tape init function.
1322  */
1323 static int
1324 tape_init (void)
1325 {
1326 	TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1327 	debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1328 #ifdef DBF_LIKE_HELL
1329 	debug_set_level(TAPE_DBF_AREA, 6);
1330 #endif
1331 	DBF_EVENT(3, "tape init\n");
1332 	tape_proc_init();
1333 	tapechar_init ();
1334 	return 0;
1335 }
1336 
1337 /*
1338  * Tape exit function.
1339  */
1340 static void
1341 tape_exit(void)
1342 {
1343 	DBF_EVENT(6, "tape exit\n");
1344 
1345 	/* Get rid of the frontends */
1346 	tapechar_exit();
1347 	tape_proc_cleanup();
1348 	debug_unregister (TAPE_DBF_AREA);
1349 }
1350 
1351 MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1352 	      "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1353 MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1354 MODULE_LICENSE("GPL");
1355 
1356 module_init(tape_init);
1357 module_exit(tape_exit);
1358 
1359 EXPORT_SYMBOL(tape_generic_remove);
1360 EXPORT_SYMBOL(tape_generic_probe);
1361 EXPORT_SYMBOL(tape_generic_online);
1362 EXPORT_SYMBOL(tape_generic_offline);
1363 EXPORT_SYMBOL(tape_generic_pm_suspend);
1364 EXPORT_SYMBOL(tape_put_device);
1365 EXPORT_SYMBOL(tape_get_device);
1366 EXPORT_SYMBOL(tape_state_verbose);
1367 EXPORT_SYMBOL(tape_op_verbose);
1368 EXPORT_SYMBOL(tape_state_set);
1369 EXPORT_SYMBOL(tape_med_state_set);
1370 EXPORT_SYMBOL(tape_alloc_request);
1371 EXPORT_SYMBOL(tape_free_request);
1372 EXPORT_SYMBOL(tape_dump_sense_dbf);
1373 EXPORT_SYMBOL(tape_do_io);
1374 EXPORT_SYMBOL(tape_do_io_async);
1375 EXPORT_SYMBOL(tape_do_io_interruptible);
1376 EXPORT_SYMBOL(tape_cancel_io);
1377 EXPORT_SYMBOL(tape_mtop);
1378