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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
34static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
35static void tape_delayed_next_request(struct work_struct *);
36static 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 */
43static LIST_HEAD(tape_device_list);
44static DEFINE_RWLOCK(tape_device_lock);
45
46/*
47 * Pointer to debug area.
48 */
49debug_info_t *TAPE_DBF_AREA = NULL;
50EXPORT_SYMBOL(TAPE_DBF_AREA);
51
52/*
53 * Printable strings for tape enumerations.
54 */
55const 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
64const 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
82static 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 */
93static ssize_t
94tape_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
102static
103DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
104
105static ssize_t
106tape_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
114static
115DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
116
117static ssize_t
118tape_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
127static
128DEVICE_ATTR(state, 0444, tape_state_show, NULL);
129
130static ssize_t
131tape_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
154static
155DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
156
157static ssize_t
158tape_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
167static
168DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
169
170static 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
179static const struct attribute_group tape_attr_group = {
180 .attrs = tape_attrs,
181};
182
183/*
184 * Tape state functions
185 */
186void
187tape_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
212struct tape_med_state_work_data {
213 struct tape_device *device;
214 enum tape_medium_state state;
215 struct work_struct work;
216};
217
218static void
219tape_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
248static void
249tape_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
262void
263tape_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 */
291static 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 */
331static int
332tape_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 */
355static void
356tape_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 */
372int
373tape_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
410out_minor:
411 tape_remove_minor(device);
412out_discipline:
413 device->discipline->cleanup_device(device);
414 device->discipline = NULL;
415out:
416 module_put(discipline->owner);
417 return rc;
418}
419
420static void
421tape_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 * Set device offline.
432 *
433 * Called by the common I/O layer if the drive should set offline on user
434 * request. We may prevent this by returning an error.
435 * Manual offline is only allowed while the drive is not in use.
436 */
437int
438tape_generic_offline(struct ccw_device *cdev)
439{
440 struct tape_device *device;
441
442 device = dev_get_drvdata(&cdev->dev);
443 if (!device) {
444 return -ENODEV;
445 }
446
447 DBF_LH(3, "(%08x): tape_generic_offline(%p)\n",
448 device->cdev_id, device);
449
450 spin_lock_irq(get_ccwdev_lock(device->cdev));
451 switch (device->tape_state) {
452 case TS_INIT:
453 case TS_NOT_OPER:
454 spin_unlock_irq(get_ccwdev_lock(device->cdev));
455 break;
456 case TS_UNUSED:
457 tape_state_set(device, TS_INIT);
458 spin_unlock_irq(get_ccwdev_lock(device->cdev));
459 tape_cleanup_device(device);
460 break;
461 default:
462 DBF_EVENT(3, "(%08x): Set offline failed "
463 "- drive in use.\n",
464 device->cdev_id);
465 spin_unlock_irq(get_ccwdev_lock(device->cdev));
466 return -EBUSY;
467 }
468
469 DBF_LH(3, "(%08x): Drive set offline.\n", device->cdev_id);
470 return 0;
471}
472
473/*
474 * Allocate memory for a new device structure.
475 */
476static struct tape_device *
477tape_alloc_device(void)
478{
479 struct tape_device *device;
480
481 device = kzalloc(sizeof(struct tape_device), GFP_KERNEL);
482 if (device == NULL) {
483 DBF_EXCEPTION(2, "ti:no mem\n");
484 return ERR_PTR(-ENOMEM);
485 }
486 device->modeset_byte = kmalloc(1, GFP_KERNEL | GFP_DMA);
487 if (device->modeset_byte == NULL) {
488 DBF_EXCEPTION(2, "ti:no mem\n");
489 kfree(device);
490 return ERR_PTR(-ENOMEM);
491 }
492 mutex_init(&device->mutex);
493 INIT_LIST_HEAD(&device->req_queue);
494 INIT_LIST_HEAD(&device->node);
495 init_waitqueue_head(&device->state_change_wq);
496 init_waitqueue_head(&device->wait_queue);
497 device->tape_state = TS_INIT;
498 device->medium_state = MS_UNKNOWN;
499 *device->modeset_byte = 0;
500 device->first_minor = -1;
501 atomic_set(&device->ref_count, 1);
502 INIT_DELAYED_WORK(&device->tape_dnr, tape_delayed_next_request);
503
504 return device;
505}
506
507/*
508 * Get a reference to an existing device structure. This will automatically
509 * increment the reference count.
510 */
511struct tape_device *
512tape_get_device(struct tape_device *device)
513{
514 int count;
515
516 count = atomic_inc_return(&device->ref_count);
517 DBF_EVENT(4, "tape_get_device(%p) = %i\n", device, count);
518 return device;
519}
520
521/*
522 * Decrease the reference counter of a devices structure. If the
523 * reference counter reaches zero free the device structure.
524 * The function returns a NULL pointer to be used by the caller
525 * for clearing reference pointers.
526 */
527void
528tape_put_device(struct tape_device *device)
529{
530 int count;
531
532 count = atomic_dec_return(&device->ref_count);
533 DBF_EVENT(4, "tape_put_device(%p) -> %i\n", device, count);
534 BUG_ON(count < 0);
535 if (count == 0) {
536 kfree(device->modeset_byte);
537 kfree(device);
538 }
539}
540
541/*
542 * Find tape device by a device index.
543 */
544struct tape_device *
545tape_find_device(int devindex)
546{
547 struct tape_device *device, *tmp;
548
549 device = ERR_PTR(-ENODEV);
550 read_lock(&tape_device_lock);
551 list_for_each_entry(tmp, &tape_device_list, node) {
552 if (tmp->first_minor / TAPE_MINORS_PER_DEV == devindex) {
553 device = tape_get_device(tmp);
554 break;
555 }
556 }
557 read_unlock(&tape_device_lock);
558 return device;
559}
560
561/*
562 * Driverfs tape probe function.
563 */
564int
565tape_generic_probe(struct ccw_device *cdev)
566{
567 struct tape_device *device;
568 int ret;
569 struct ccw_dev_id dev_id;
570
571 device = tape_alloc_device();
572 if (IS_ERR(device))
573 return -ENODEV;
574 ccw_device_set_options(cdev, CCWDEV_DO_PATHGROUP |
575 CCWDEV_DO_MULTIPATH);
576 ret = sysfs_create_group(&cdev->dev.kobj, &tape_attr_group);
577 if (ret) {
578 tape_put_device(device);
579 return ret;
580 }
581 dev_set_drvdata(&cdev->dev, device);
582 cdev->handler = __tape_do_irq;
583 device->cdev = cdev;
584 ccw_device_get_id(cdev, &dev_id);
585 device->cdev_id = devid_to_int(&dev_id);
586 return ret;
587}
588
589static void
590__tape_discard_requests(struct tape_device *device)
591{
592 struct tape_request * request;
593 struct list_head * l, *n;
594
595 list_for_each_safe(l, n, &device->req_queue) {
596 request = list_entry(l, struct tape_request, list);
597 if (request->status == TAPE_REQUEST_IN_IO)
598 request->status = TAPE_REQUEST_DONE;
599 list_del(&request->list);
600
601 /* Decrease ref_count for removed request. */
602 request->device = NULL;
603 tape_put_device(device);
604 request->rc = -EIO;
605 if (request->callback != NULL)
606 request->callback(request, request->callback_data);
607 }
608}
609
610/*
611 * Driverfs tape remove function.
612 *
613 * This function is called whenever the common I/O layer detects the device
614 * gone. This can happen at any time and we cannot refuse.
615 */
616void
617tape_generic_remove(struct ccw_device *cdev)
618{
619 struct tape_device * device;
620
621 device = dev_get_drvdata(&cdev->dev);
622 if (!device) {
623 return;
624 }
625 DBF_LH(3, "(%08x): tape_generic_remove(%p)\n", device->cdev_id, cdev);
626
627 spin_lock_irq(get_ccwdev_lock(device->cdev));
628 switch (device->tape_state) {
629 case TS_INIT:
630 tape_state_set(device, TS_NOT_OPER);
631 fallthrough;
632 case TS_NOT_OPER:
633 /*
634 * Nothing to do.
635 */
636 spin_unlock_irq(get_ccwdev_lock(device->cdev));
637 break;
638 case TS_UNUSED:
639 /*
640 * Need only to release the device.
641 */
642 tape_state_set(device, TS_NOT_OPER);
643 spin_unlock_irq(get_ccwdev_lock(device->cdev));
644 tape_cleanup_device(device);
645 break;
646 default:
647 /*
648 * There may be requests on the queue. We will not get
649 * an interrupt for a request that was running. So we
650 * just post them all as I/O errors.
651 */
652 DBF_EVENT(3, "(%08x): Drive in use vanished!\n",
653 device->cdev_id);
654 pr_warn("%s: A tape unit was detached while in use\n",
655 dev_name(&device->cdev->dev));
656 tape_state_set(device, TS_NOT_OPER);
657 __tape_discard_requests(device);
658 spin_unlock_irq(get_ccwdev_lock(device->cdev));
659 tape_cleanup_device(device);
660 }
661
662 device = dev_get_drvdata(&cdev->dev);
663 if (device) {
664 sysfs_remove_group(&cdev->dev.kobj, &tape_attr_group);
665 dev_set_drvdata(&cdev->dev, NULL);
666 tape_put_device(device);
667 }
668}
669
670/*
671 * Allocate a new tape ccw request
672 */
673struct tape_request *
674tape_alloc_request(int cplength, int datasize)
675{
676 struct tape_request *request;
677
678 BUG_ON(datasize > PAGE_SIZE || (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
679
680 DBF_LH(6, "tape_alloc_request(%d, %d)\n", cplength, datasize);
681
682 request = kzalloc(sizeof(struct tape_request), GFP_KERNEL);
683 if (request == NULL) {
684 DBF_EXCEPTION(1, "cqra nomem\n");
685 return ERR_PTR(-ENOMEM);
686 }
687 /* allocate channel program */
688 if (cplength > 0) {
689 request->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
690 GFP_ATOMIC | GFP_DMA);
691 if (request->cpaddr == NULL) {
692 DBF_EXCEPTION(1, "cqra nomem\n");
693 kfree(request);
694 return ERR_PTR(-ENOMEM);
695 }
696 }
697 /* alloc small kernel buffer */
698 if (datasize > 0) {
699 request->cpdata = kzalloc(datasize, GFP_KERNEL | GFP_DMA);
700 if (request->cpdata == NULL) {
701 DBF_EXCEPTION(1, "cqra nomem\n");
702 kfree(request->cpaddr);
703 kfree(request);
704 return ERR_PTR(-ENOMEM);
705 }
706 }
707 DBF_LH(6, "New request %p(%p/%p)\n", request, request->cpaddr,
708 request->cpdata);
709
710 return request;
711}
712
713/*
714 * Free tape ccw request
715 */
716void
717tape_free_request (struct tape_request * request)
718{
719 DBF_LH(6, "Free request %p\n", request);
720
721 if (request->device)
722 tape_put_device(request->device);
723 kfree(request->cpdata);
724 kfree(request->cpaddr);
725 kfree(request);
726}
727
728static int
729__tape_start_io(struct tape_device *device, struct tape_request *request)
730{
731 int rc;
732
733 rc = ccw_device_start(
734 device->cdev,
735 request->cpaddr,
736 (unsigned long) request,
737 0x00,
738 request->options
739 );
740 if (rc == 0) {
741 request->status = TAPE_REQUEST_IN_IO;
742 } else if (rc == -EBUSY) {
743 /* The common I/O subsystem is currently busy. Retry later. */
744 request->status = TAPE_REQUEST_QUEUED;
745 schedule_delayed_work(&device->tape_dnr, 0);
746 rc = 0;
747 } else {
748 /* Start failed. Remove request and indicate failure. */
749 DBF_EVENT(1, "tape: start request failed with RC = %i\n", rc);
750 }
751 return rc;
752}
753
754static void
755__tape_start_next_request(struct tape_device *device)
756{
757 struct list_head *l, *n;
758 struct tape_request *request;
759 int rc;
760
761 DBF_LH(6, "__tape_start_next_request(%p)\n", device);
762 /*
763 * Try to start each request on request queue until one is
764 * started successful.
765 */
766 list_for_each_safe(l, n, &device->req_queue) {
767 request = list_entry(l, struct tape_request, list);
768
769 /*
770 * Avoid race condition if bottom-half was triggered more than
771 * once.
772 */
773 if (request->status == TAPE_REQUEST_IN_IO)
774 return;
775 /*
776 * Request has already been stopped. We have to wait until
777 * the request is removed from the queue in the interrupt
778 * handling.
779 */
780 if (request->status == TAPE_REQUEST_DONE)
781 return;
782
783 /*
784 * We wanted to cancel the request but the common I/O layer
785 * was busy at that time. This can only happen if this
786 * function is called by delayed_next_request.
787 * Otherwise we start the next request on the queue.
788 */
789 if (request->status == TAPE_REQUEST_CANCEL) {
790 rc = __tape_cancel_io(device, request);
791 } else {
792 rc = __tape_start_io(device, request);
793 }
794 if (rc == 0)
795 return;
796
797 /* Set ending status. */
798 request->rc = rc;
799 request->status = TAPE_REQUEST_DONE;
800
801 /* Remove from request queue. */
802 list_del(&request->list);
803
804 /* Do callback. */
805 if (request->callback != NULL)
806 request->callback(request, request->callback_data);
807 }
808}
809
810static void
811tape_delayed_next_request(struct work_struct *work)
812{
813 struct tape_device *device =
814 container_of(work, struct tape_device, tape_dnr.work);
815
816 DBF_LH(6, "tape_delayed_next_request(%p)\n", device);
817 spin_lock_irq(get_ccwdev_lock(device->cdev));
818 __tape_start_next_request(device);
819 spin_unlock_irq(get_ccwdev_lock(device->cdev));
820}
821
822static void tape_long_busy_timeout(struct timer_list *t)
823{
824 struct tape_device *device = from_timer(device, t, lb_timeout);
825 struct tape_request *request;
826
827 spin_lock_irq(get_ccwdev_lock(device->cdev));
828 request = list_entry(device->req_queue.next, struct tape_request, list);
829 BUG_ON(request->status != TAPE_REQUEST_LONG_BUSY);
830 DBF_LH(6, "%08x: Long busy timeout.\n", device->cdev_id);
831 __tape_start_next_request(device);
832 tape_put_device(device);
833 spin_unlock_irq(get_ccwdev_lock(device->cdev));
834}
835
836static void
837__tape_end_request(
838 struct tape_device * device,
839 struct tape_request * request,
840 int rc)
841{
842 DBF_LH(6, "__tape_end_request(%p, %p, %i)\n", device, request, rc);
843 if (request) {
844 request->rc = rc;
845 request->status = TAPE_REQUEST_DONE;
846
847 /* Remove from request queue. */
848 list_del(&request->list);
849
850 /* Do callback. */
851 if (request->callback != NULL)
852 request->callback(request, request->callback_data);
853 }
854
855 /* Start next request. */
856 if (!list_empty(&device->req_queue))
857 __tape_start_next_request(device);
858}
859
860/*
861 * Write sense data to dbf
862 */
863void
864tape_dump_sense_dbf(struct tape_device *device, struct tape_request *request,
865 struct irb *irb)
866{
867 unsigned int *sptr;
868 const char* op;
869
870 if (request != NULL)
871 op = tape_op_verbose[request->op];
872 else
873 op = "---";
874 DBF_EVENT(3, "DSTAT : %02x CSTAT: %02x\n",
875 irb->scsw.cmd.dstat, irb->scsw.cmd.cstat);
876 DBF_EVENT(3, "DEVICE: %08x OP\t: %s\n", device->cdev_id, op);
877 sptr = (unsigned int *) irb->ecw;
878 DBF_EVENT(3, "%08x %08x\n", sptr[0], sptr[1]);
879 DBF_EVENT(3, "%08x %08x\n", sptr[2], sptr[3]);
880 DBF_EVENT(3, "%08x %08x\n", sptr[4], sptr[5]);
881 DBF_EVENT(3, "%08x %08x\n", sptr[6], sptr[7]);
882}
883
884/*
885 * I/O helper function. Adds the request to the request queue
886 * and starts it if the tape is idle. Has to be called with
887 * the device lock held.
888 */
889static int
890__tape_start_request(struct tape_device *device, struct tape_request *request)
891{
892 int rc;
893
894 switch (request->op) {
895 case TO_MSEN:
896 case TO_ASSIGN:
897 case TO_UNASSIGN:
898 case TO_READ_ATTMSG:
899 case TO_RDC:
900 if (device->tape_state == TS_INIT)
901 break;
902 if (device->tape_state == TS_UNUSED)
903 break;
904 fallthrough;
905 default:
906 if (device->tape_state == TS_BLKUSE)
907 break;
908 if (device->tape_state != TS_IN_USE)
909 return -ENODEV;
910 }
911
912 /* Increase use count of device for the added request. */
913 request->device = tape_get_device(device);
914
915 if (list_empty(&device->req_queue)) {
916 /* No other requests are on the queue. Start this one. */
917 rc = __tape_start_io(device, request);
918 if (rc)
919 return rc;
920
921 DBF_LH(5, "Request %p added for execution.\n", request);
922 list_add(&request->list, &device->req_queue);
923 } else {
924 DBF_LH(5, "Request %p add to queue.\n", request);
925 request->status = TAPE_REQUEST_QUEUED;
926 list_add_tail(&request->list, &device->req_queue);
927 }
928 return 0;
929}
930
931/*
932 * Add the request to the request queue, try to start it if the
933 * tape is idle. Return without waiting for end of i/o.
934 */
935int
936tape_do_io_async(struct tape_device *device, struct tape_request *request)
937{
938 int rc;
939
940 DBF_LH(6, "tape_do_io_async(%p, %p)\n", device, request);
941
942 spin_lock_irq(get_ccwdev_lock(device->cdev));
943 /* Add request to request queue and try to start it. */
944 rc = __tape_start_request(device, request);
945 spin_unlock_irq(get_ccwdev_lock(device->cdev));
946 return rc;
947}
948
949/*
950 * tape_do_io/__tape_wake_up
951 * Add the request to the request queue, try to start it if the
952 * tape is idle and wait uninterruptible for its completion.
953 */
954static void
955__tape_wake_up(struct tape_request *request, void *data)
956{
957 request->callback = NULL;
958 wake_up((wait_queue_head_t *) data);
959}
960
961int
962tape_do_io(struct tape_device *device, struct tape_request *request)
963{
964 int rc;
965
966 spin_lock_irq(get_ccwdev_lock(device->cdev));
967 /* Setup callback */
968 request->callback = __tape_wake_up;
969 request->callback_data = &device->wait_queue;
970 /* Add request to request queue and try to start it. */
971 rc = __tape_start_request(device, request);
972 spin_unlock_irq(get_ccwdev_lock(device->cdev));
973 if (rc)
974 return rc;
975 /* Request added to the queue. Wait for its completion. */
976 wait_event(device->wait_queue, (request->callback == NULL));
977 /* Get rc from request */
978 return request->rc;
979}
980
981/*
982 * tape_do_io_interruptible/__tape_wake_up_interruptible
983 * Add the request to the request queue, try to start it if the
984 * tape is idle and wait uninterruptible for its completion.
985 */
986static void
987__tape_wake_up_interruptible(struct tape_request *request, void *data)
988{
989 request->callback = NULL;
990 wake_up_interruptible((wait_queue_head_t *) data);
991}
992
993int
994tape_do_io_interruptible(struct tape_device *device,
995 struct tape_request *request)
996{
997 int rc;
998
999 spin_lock_irq(get_ccwdev_lock(device->cdev));
1000 /* Setup callback */
1001 request->callback = __tape_wake_up_interruptible;
1002 request->callback_data = &device->wait_queue;
1003 rc = __tape_start_request(device, request);
1004 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1005 if (rc)
1006 return rc;
1007 /* Request added to the queue. Wait for its completion. */
1008 rc = wait_event_interruptible(device->wait_queue,
1009 (request->callback == NULL));
1010 if (rc != -ERESTARTSYS)
1011 /* Request finished normally. */
1012 return request->rc;
1013
1014 /* Interrupted by a signal. We have to stop the current request. */
1015 spin_lock_irq(get_ccwdev_lock(device->cdev));
1016 rc = __tape_cancel_io(device, request);
1017 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1018 if (rc == 0) {
1019 /* Wait for the interrupt that acknowledges the halt. */
1020 do {
1021 rc = wait_event_interruptible(
1022 device->wait_queue,
1023 (request->callback == NULL)
1024 );
1025 } while (rc == -ERESTARTSYS);
1026
1027 DBF_EVENT(3, "IO stopped on %08x\n", device->cdev_id);
1028 rc = -ERESTARTSYS;
1029 }
1030 return rc;
1031}
1032
1033/*
1034 * Stop running ccw.
1035 */
1036int
1037tape_cancel_io(struct tape_device *device, struct tape_request *request)
1038{
1039 int rc;
1040
1041 spin_lock_irq(get_ccwdev_lock(device->cdev));
1042 rc = __tape_cancel_io(device, request);
1043 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1044 return rc;
1045}
1046
1047/*
1048 * Tape interrupt routine, called from the ccw_device layer
1049 */
1050static void
1051__tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb)
1052{
1053 struct tape_device *device;
1054 struct tape_request *request;
1055 int rc;
1056
1057 device = dev_get_drvdata(&cdev->dev);
1058 if (device == NULL) {
1059 return;
1060 }
1061 request = (struct tape_request *) intparm;
1062
1063 DBF_LH(6, "__tape_do_irq(device=%p, request=%p)\n", device, request);
1064
1065 /* On special conditions irb is an error pointer */
1066 if (IS_ERR(irb)) {
1067 /* FIXME: What to do with the request? */
1068 switch (PTR_ERR(irb)) {
1069 case -ETIMEDOUT:
1070 DBF_LH(1, "(%08x): Request timed out\n",
1071 device->cdev_id);
1072 fallthrough;
1073 case -EIO:
1074 __tape_end_request(device, request, -EIO);
1075 break;
1076 default:
1077 DBF_LH(1, "(%08x): Unexpected i/o error %li\n",
1078 device->cdev_id, PTR_ERR(irb));
1079 }
1080 return;
1081 }
1082
1083 /*
1084 * If the condition code is not zero and the start function bit is
1085 * still set, this is an deferred error and the last start I/O did
1086 * not succeed. At this point the condition that caused the deferred
1087 * error might still apply. So we just schedule the request to be
1088 * started later.
1089 */
1090 if (irb->scsw.cmd.cc != 0 &&
1091 (irb->scsw.cmd.fctl & SCSW_FCTL_START_FUNC) &&
1092 (request->status == TAPE_REQUEST_IN_IO)) {
1093 DBF_EVENT(3,"(%08x): deferred cc=%i, fctl=%i. restarting\n",
1094 device->cdev_id, irb->scsw.cmd.cc, irb->scsw.cmd.fctl);
1095 request->status = TAPE_REQUEST_QUEUED;
1096 schedule_delayed_work(&device->tape_dnr, HZ);
1097 return;
1098 }
1099
1100 /* May be an unsolicited irq */
1101 if(request != NULL)
1102 request->rescnt = irb->scsw.cmd.count;
1103 else if ((irb->scsw.cmd.dstat == 0x85 || irb->scsw.cmd.dstat == 0x80) &&
1104 !list_empty(&device->req_queue)) {
1105 /* Not Ready to Ready after long busy ? */
1106 struct tape_request *req;
1107 req = list_entry(device->req_queue.next,
1108 struct tape_request, list);
1109 if (req->status == TAPE_REQUEST_LONG_BUSY) {
1110 DBF_EVENT(3, "(%08x): del timer\n", device->cdev_id);
1111 if (del_timer(&device->lb_timeout)) {
1112 tape_put_device(device);
1113 __tape_start_next_request(device);
1114 }
1115 return;
1116 }
1117 }
1118 if (irb->scsw.cmd.dstat != 0x0c) {
1119 /* Set the 'ONLINE' flag depending on sense byte 1 */
1120 if(*(((__u8 *) irb->ecw) + 1) & SENSE_DRIVE_ONLINE)
1121 device->tape_generic_status |= GMT_ONLINE(~0);
1122 else
1123 device->tape_generic_status &= ~GMT_ONLINE(~0);
1124
1125 /*
1126 * Any request that does not come back with channel end
1127 * and device end is unusual. Log the sense data.
1128 */
1129 DBF_EVENT(3,"-- Tape Interrupthandler --\n");
1130 tape_dump_sense_dbf(device, request, irb);
1131 } else {
1132 /* Upon normal completion the device _is_ online */
1133 device->tape_generic_status |= GMT_ONLINE(~0);
1134 }
1135 if (device->tape_state == TS_NOT_OPER) {
1136 DBF_EVENT(6, "tape:device is not operational\n");
1137 return;
1138 }
1139
1140 /*
1141 * Request that were canceled still come back with an interrupt.
1142 * To detect these request the state will be set to TAPE_REQUEST_DONE.
1143 */
1144 if(request != NULL && request->status == TAPE_REQUEST_DONE) {
1145 __tape_end_request(device, request, -EIO);
1146 return;
1147 }
1148
1149 rc = device->discipline->irq(device, request, irb);
1150 /*
1151 * rc < 0 : request finished unsuccessfully.
1152 * rc == TAPE_IO_SUCCESS: request finished successfully.
1153 * rc == TAPE_IO_PENDING: request is still running. Ignore rc.
1154 * rc == TAPE_IO_RETRY: request finished but needs another go.
1155 * rc == TAPE_IO_STOP: request needs to get terminated.
1156 */
1157 switch (rc) {
1158 case TAPE_IO_SUCCESS:
1159 /* Upon normal completion the device _is_ online */
1160 device->tape_generic_status |= GMT_ONLINE(~0);
1161 __tape_end_request(device, request, rc);
1162 break;
1163 case TAPE_IO_PENDING:
1164 break;
1165 case TAPE_IO_LONG_BUSY:
1166 device->lb_timeout.expires = jiffies +
1167 LONG_BUSY_TIMEOUT * HZ;
1168 DBF_EVENT(3, "(%08x): add timer\n", device->cdev_id);
1169 add_timer(&device->lb_timeout);
1170 request->status = TAPE_REQUEST_LONG_BUSY;
1171 break;
1172 case TAPE_IO_RETRY:
1173 rc = __tape_start_io(device, request);
1174 if (rc)
1175 __tape_end_request(device, request, rc);
1176 break;
1177 case TAPE_IO_STOP:
1178 rc = __tape_cancel_io(device, request);
1179 if (rc)
1180 __tape_end_request(device, request, rc);
1181 break;
1182 default:
1183 if (rc > 0) {
1184 DBF_EVENT(6, "xunknownrc\n");
1185 __tape_end_request(device, request, -EIO);
1186 } else {
1187 __tape_end_request(device, request, rc);
1188 }
1189 break;
1190 }
1191}
1192
1193/*
1194 * Tape device open function used by tape_char frontend.
1195 */
1196int
1197tape_open(struct tape_device *device)
1198{
1199 int rc;
1200
1201 spin_lock_irq(get_ccwdev_lock(device->cdev));
1202 if (device->tape_state == TS_NOT_OPER) {
1203 DBF_EVENT(6, "TAPE:nodev\n");
1204 rc = -ENODEV;
1205 } else if (device->tape_state == TS_IN_USE) {
1206 DBF_EVENT(6, "TAPE:dbusy\n");
1207 rc = -EBUSY;
1208 } else if (device->tape_state == TS_BLKUSE) {
1209 DBF_EVENT(6, "TAPE:dbusy\n");
1210 rc = -EBUSY;
1211 } else if (device->discipline != NULL &&
1212 !try_module_get(device->discipline->owner)) {
1213 DBF_EVENT(6, "TAPE:nodisc\n");
1214 rc = -ENODEV;
1215 } else {
1216 tape_state_set(device, TS_IN_USE);
1217 rc = 0;
1218 }
1219 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1220 return rc;
1221}
1222
1223/*
1224 * Tape device release function used by tape_char frontend.
1225 */
1226int
1227tape_release(struct tape_device *device)
1228{
1229 spin_lock_irq(get_ccwdev_lock(device->cdev));
1230 if (device->tape_state == TS_IN_USE)
1231 tape_state_set(device, TS_UNUSED);
1232 module_put(device->discipline->owner);
1233 spin_unlock_irq(get_ccwdev_lock(device->cdev));
1234 return 0;
1235}
1236
1237/*
1238 * Execute a magnetic tape command a number of times.
1239 */
1240int
1241tape_mtop(struct tape_device *device, int mt_op, int mt_count)
1242{
1243 tape_mtop_fn fn;
1244 int rc;
1245
1246 DBF_EVENT(6, "TAPE:mtio\n");
1247 DBF_EVENT(6, "TAPE:ioop: %x\n", mt_op);
1248 DBF_EVENT(6, "TAPE:arg: %x\n", mt_count);
1249
1250 if (mt_op < 0 || mt_op >= TAPE_NR_MTOPS)
1251 return -EINVAL;
1252 fn = device->discipline->mtop_array[mt_op];
1253 if (fn == NULL)
1254 return -EINVAL;
1255
1256 /* We assume that the backends can handle count up to 500. */
1257 if (mt_op == MTBSR || mt_op == MTFSR || mt_op == MTFSF ||
1258 mt_op == MTBSF || mt_op == MTFSFM || mt_op == MTBSFM) {
1259 rc = 0;
1260 for (; mt_count > 500; mt_count -= 500)
1261 if ((rc = fn(device, 500)) != 0)
1262 break;
1263 if (rc == 0)
1264 rc = fn(device, mt_count);
1265 } else
1266 rc = fn(device, mt_count);
1267 return rc;
1268
1269}
1270
1271/*
1272 * Tape init function.
1273 */
1274static int
1275tape_init (void)
1276{
1277 TAPE_DBF_AREA = debug_register ( "tape", 2, 2, 4*sizeof(long));
1278 debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
1279#ifdef DBF_LIKE_HELL
1280 debug_set_level(TAPE_DBF_AREA, 6);
1281#endif
1282 DBF_EVENT(3, "tape init\n");
1283 tape_proc_init();
1284 tapechar_init ();
1285 return 0;
1286}
1287
1288/*
1289 * Tape exit function.
1290 */
1291static void
1292tape_exit(void)
1293{
1294 DBF_EVENT(6, "tape exit\n");
1295
1296 /* Get rid of the frontends */
1297 tapechar_exit();
1298 tape_proc_cleanup();
1299 debug_unregister (TAPE_DBF_AREA);
1300}
1301
1302MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1303 "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1304MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1305MODULE_LICENSE("GPL");
1306
1307module_init(tape_init);
1308module_exit(tape_exit);
1309
1310EXPORT_SYMBOL(tape_generic_remove);
1311EXPORT_SYMBOL(tape_generic_probe);
1312EXPORT_SYMBOL(tape_generic_online);
1313EXPORT_SYMBOL(tape_generic_offline);
1314EXPORT_SYMBOL(tape_put_device);
1315EXPORT_SYMBOL(tape_get_device);
1316EXPORT_SYMBOL(tape_state_verbose);
1317EXPORT_SYMBOL(tape_op_verbose);
1318EXPORT_SYMBOL(tape_state_set);
1319EXPORT_SYMBOL(tape_med_state_set);
1320EXPORT_SYMBOL(tape_alloc_request);
1321EXPORT_SYMBOL(tape_free_request);
1322EXPORT_SYMBOL(tape_dump_sense_dbf);
1323EXPORT_SYMBOL(tape_do_io);
1324EXPORT_SYMBOL(tape_do_io_async);
1325EXPORT_SYMBOL(tape_do_io_interruptible);
1326EXPORT_SYMBOL(tape_cancel_io);
1327EXPORT_SYMBOL(tape_mtop);
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
34static void __tape_do_irq (struct ccw_device *, unsigned long, struct irb *);
35static void tape_delayed_next_request(struct work_struct *);
36static 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 */
43static LIST_HEAD(tape_device_list);
44static DEFINE_RWLOCK(tape_device_lock);
45
46/*
47 * Pointer to debug area.
48 */
49debug_info_t *TAPE_DBF_AREA = NULL;
50EXPORT_SYMBOL(TAPE_DBF_AREA);
51
52/*
53 * Printable strings for tape enumerations.
54 */
55const 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
64const 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
82static 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 */
93static ssize_t
94tape_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
102static
103DEVICE_ATTR(medium_state, 0444, tape_medium_state_show, NULL);
104
105static ssize_t
106tape_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
114static
115DEVICE_ATTR(first_minor, 0444, tape_first_minor_show, NULL);
116
117static ssize_t
118tape_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
127static
128DEVICE_ATTR(state, 0444, tape_state_show, NULL);
129
130static ssize_t
131tape_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
154static
155DEVICE_ATTR(operation, 0444, tape_operation_show, NULL);
156
157static ssize_t
158tape_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
167static
168DEVICE_ATTR(blocksize, 0444, tape_blocksize_show, NULL);
169
170static 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
179static const struct attribute_group tape_attr_group = {
180 .attrs = tape_attrs,
181};
182
183/*
184 * Tape state functions
185 */
186void
187tape_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
212struct tape_med_state_work_data {
213 struct tape_device *device;
214 enum tape_medium_state state;
215 struct work_struct work;
216};
217
218static void
219tape_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
248static void
249tape_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
262void
263tape_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 */
291static 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 */
331static int
332tape_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 */
355static void
356tape_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 */
372int
373tape_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
410out_minor:
411 tape_remove_minor(device);
412out_discipline:
413 device->discipline->cleanup_device(device);
414 device->discipline = NULL;
415out:
416 module_put(discipline->owner);
417 return rc;
418}
419
420static void
421tape_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 */
443int 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 */
486int
487tape_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 */
525static struct tape_device *
526tape_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 */
560struct tape_device *
561tape_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 */
576void
577tape_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 */
593struct tape_device *
594tape_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 */
613int
614tape_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
638static 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 */
665void
666tape_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 */
722struct tape_request *
723tape_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 */
765void
766tape_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
777static 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
803static 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
859static void
860tape_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
871static 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
885static 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 */
912void
913tape_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 */
938static 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 */
984int
985tape_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 */
1003static 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
1010int
1011tape_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 */
1035static 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
1042int
1043tape_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 */
1085int
1086tape_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 */
1099static 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 */
1245int
1246tape_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 */
1275int
1276tape_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 */
1289int
1290tape_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 */
1323static int
1324tape_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 */
1340static void
1341tape_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
1351MODULE_AUTHOR("(C) 2001 IBM Deutschland Entwicklung GmbH by Carsten Otte and "
1352 "Michael Holzheu (cotte@de.ibm.com,holzheu@de.ibm.com)");
1353MODULE_DESCRIPTION("Linux on zSeries channel attached tape device driver");
1354MODULE_LICENSE("GPL");
1355
1356module_init(tape_init);
1357module_exit(tape_exit);
1358
1359EXPORT_SYMBOL(tape_generic_remove);
1360EXPORT_SYMBOL(tape_generic_probe);
1361EXPORT_SYMBOL(tape_generic_online);
1362EXPORT_SYMBOL(tape_generic_offline);
1363EXPORT_SYMBOL(tape_generic_pm_suspend);
1364EXPORT_SYMBOL(tape_put_device);
1365EXPORT_SYMBOL(tape_get_device);
1366EXPORT_SYMBOL(tape_state_verbose);
1367EXPORT_SYMBOL(tape_op_verbose);
1368EXPORT_SYMBOL(tape_state_set);
1369EXPORT_SYMBOL(tape_med_state_set);
1370EXPORT_SYMBOL(tape_alloc_request);
1371EXPORT_SYMBOL(tape_free_request);
1372EXPORT_SYMBOL(tape_dump_sense_dbf);
1373EXPORT_SYMBOL(tape_do_io);
1374EXPORT_SYMBOL(tape_do_io_async);
1375EXPORT_SYMBOL(tape_do_io_interruptible);
1376EXPORT_SYMBOL(tape_cancel_io);
1377EXPORT_SYMBOL(tape_mtop);