xref: /openbmc/linux/drivers/s390/block/dasd.c (revision c4a7b9b5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  *		    Horst Hummel <Horst.Hummel@de.ibm.com>
5  *		    Carsten Otte <Cotte@de.ibm.com>
6  *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
7  * Bugreports.to..: <Linux390@de.ibm.com>
8  * Copyright IBM Corp. 1999, 2009
9  */
10 
11 #define KMSG_COMPONENT "dasd"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 
14 #include <linux/kmod.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/ctype.h>
18 #include <linux/major.h>
19 #include <linux/slab.h>
20 #include <linux/hdreg.h>
21 #include <linux/async.h>
22 #include <linux/mutex.h>
23 #include <linux/debugfs.h>
24 #include <linux/seq_file.h>
25 #include <linux/vmalloc.h>
26 
27 #include <asm/ccwdev.h>
28 #include <asm/ebcdic.h>
29 #include <asm/idals.h>
30 #include <asm/itcw.h>
31 #include <asm/diag.h>
32 
33 /* This is ugly... */
34 #define PRINTK_HEADER "dasd:"
35 
36 #include "dasd_int.h"
37 /*
38  * SECTION: Constant definitions to be used within this file
39  */
40 #define DASD_CHANQ_MAX_SIZE 4
41 
42 #define DASD_DIAG_MOD		"dasd_diag_mod"
43 
44 /*
45  * SECTION: exported variables of dasd.c
46  */
47 debug_info_t *dasd_debug_area;
48 EXPORT_SYMBOL(dasd_debug_area);
49 static struct dentry *dasd_debugfs_root_entry;
50 struct dasd_discipline *dasd_diag_discipline_pointer;
51 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
52 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
53 
54 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
55 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
56 		   " Copyright IBM Corp. 2000");
57 MODULE_LICENSE("GPL");
58 
59 /*
60  * SECTION: prototypes for static functions of dasd.c
61  */
62 static int dasd_flush_block_queue(struct dasd_block *);
63 static void dasd_device_tasklet(unsigned long);
64 static void dasd_block_tasklet(unsigned long);
65 static void do_kick_device(struct work_struct *);
66 static void do_reload_device(struct work_struct *);
67 static void do_requeue_requests(struct work_struct *);
68 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
69 static void dasd_device_timeout(struct timer_list *);
70 static void dasd_block_timeout(struct timer_list *);
71 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
72 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
73 static void dasd_profile_exit(struct dasd_profile *);
74 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
75 static void dasd_hosts_exit(struct dasd_device *);
76 
77 /*
78  * SECTION: Operations on the device structure.
79  */
80 static wait_queue_head_t dasd_init_waitq;
81 static wait_queue_head_t dasd_flush_wq;
82 static wait_queue_head_t generic_waitq;
83 static wait_queue_head_t shutdown_waitq;
84 
85 /*
86  * Allocate memory for a new device structure.
87  */
88 struct dasd_device *dasd_alloc_device(void)
89 {
90 	struct dasd_device *device;
91 
92 	device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
93 	if (!device)
94 		return ERR_PTR(-ENOMEM);
95 
96 	/* Get two pages for normal block device operations. */
97 	device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
98 	if (!device->ccw_mem) {
99 		kfree(device);
100 		return ERR_PTR(-ENOMEM);
101 	}
102 	/* Get one page for error recovery. */
103 	device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
104 	if (!device->erp_mem) {
105 		free_pages((unsigned long) device->ccw_mem, 1);
106 		kfree(device);
107 		return ERR_PTR(-ENOMEM);
108 	}
109 	/* Get two pages for ese format. */
110 	device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
111 	if (!device->ese_mem) {
112 		free_page((unsigned long) device->erp_mem);
113 		free_pages((unsigned long) device->ccw_mem, 1);
114 		kfree(device);
115 		return ERR_PTR(-ENOMEM);
116 	}
117 
118 	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
119 	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
120 	dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
121 	spin_lock_init(&device->mem_lock);
122 	atomic_set(&device->tasklet_scheduled, 0);
123 	tasklet_init(&device->tasklet, dasd_device_tasklet,
124 		     (unsigned long) device);
125 	INIT_LIST_HEAD(&device->ccw_queue);
126 	timer_setup(&device->timer, dasd_device_timeout, 0);
127 	INIT_WORK(&device->kick_work, do_kick_device);
128 	INIT_WORK(&device->reload_device, do_reload_device);
129 	INIT_WORK(&device->requeue_requests, do_requeue_requests);
130 	device->state = DASD_STATE_NEW;
131 	device->target = DASD_STATE_NEW;
132 	mutex_init(&device->state_mutex);
133 	spin_lock_init(&device->profile.lock);
134 	return device;
135 }
136 
137 /*
138  * Free memory of a device structure.
139  */
140 void dasd_free_device(struct dasd_device *device)
141 {
142 	kfree(device->private);
143 	free_pages((unsigned long) device->ese_mem, 1);
144 	free_page((unsigned long) device->erp_mem);
145 	free_pages((unsigned long) device->ccw_mem, 1);
146 	kfree(device);
147 }
148 
149 /*
150  * Allocate memory for a new device structure.
151  */
152 struct dasd_block *dasd_alloc_block(void)
153 {
154 	struct dasd_block *block;
155 
156 	block = kzalloc(sizeof(*block), GFP_ATOMIC);
157 	if (!block)
158 		return ERR_PTR(-ENOMEM);
159 	/* open_count = 0 means device online but not in use */
160 	atomic_set(&block->open_count, -1);
161 
162 	atomic_set(&block->tasklet_scheduled, 0);
163 	tasklet_init(&block->tasklet, dasd_block_tasklet,
164 		     (unsigned long) block);
165 	INIT_LIST_HEAD(&block->ccw_queue);
166 	spin_lock_init(&block->queue_lock);
167 	INIT_LIST_HEAD(&block->format_list);
168 	spin_lock_init(&block->format_lock);
169 	timer_setup(&block->timer, dasd_block_timeout, 0);
170 	spin_lock_init(&block->profile.lock);
171 
172 	return block;
173 }
174 EXPORT_SYMBOL_GPL(dasd_alloc_block);
175 
176 /*
177  * Free memory of a device structure.
178  */
179 void dasd_free_block(struct dasd_block *block)
180 {
181 	kfree(block);
182 }
183 EXPORT_SYMBOL_GPL(dasd_free_block);
184 
185 /*
186  * Make a new device known to the system.
187  */
188 static int dasd_state_new_to_known(struct dasd_device *device)
189 {
190 	/*
191 	 * As long as the device is not in state DASD_STATE_NEW we want to
192 	 * keep the reference count > 0.
193 	 */
194 	dasd_get_device(device);
195 	device->state = DASD_STATE_KNOWN;
196 	return 0;
197 }
198 
199 /*
200  * Let the system forget about a device.
201  */
202 static int dasd_state_known_to_new(struct dasd_device *device)
203 {
204 	/* Disable extended error reporting for this device. */
205 	dasd_eer_disable(device);
206 	device->state = DASD_STATE_NEW;
207 
208 	/* Give up reference we took in dasd_state_new_to_known. */
209 	dasd_put_device(device);
210 	return 0;
211 }
212 
213 static struct dentry *dasd_debugfs_setup(const char *name,
214 					 struct dentry *base_dentry)
215 {
216 	struct dentry *pde;
217 
218 	if (!base_dentry)
219 		return NULL;
220 	pde = debugfs_create_dir(name, base_dentry);
221 	if (!pde || IS_ERR(pde))
222 		return NULL;
223 	return pde;
224 }
225 
226 /*
227  * Request the irq line for the device.
228  */
229 static int dasd_state_known_to_basic(struct dasd_device *device)
230 {
231 	struct dasd_block *block = device->block;
232 	int rc = 0;
233 
234 	/* Allocate and register gendisk structure. */
235 	if (block) {
236 		rc = dasd_gendisk_alloc(block);
237 		if (rc)
238 			return rc;
239 		block->debugfs_dentry =
240 			dasd_debugfs_setup(block->gdp->disk_name,
241 					   dasd_debugfs_root_entry);
242 		dasd_profile_init(&block->profile, block->debugfs_dentry);
243 		if (dasd_global_profile_level == DASD_PROFILE_ON)
244 			dasd_profile_on(&device->block->profile);
245 	}
246 	device->debugfs_dentry =
247 		dasd_debugfs_setup(dev_name(&device->cdev->dev),
248 				   dasd_debugfs_root_entry);
249 	dasd_profile_init(&device->profile, device->debugfs_dentry);
250 	dasd_hosts_init(device->debugfs_dentry, device);
251 
252 	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
253 	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
254 					    8 * sizeof(long));
255 	debug_register_view(device->debug_area, &debug_sprintf_view);
256 	debug_set_level(device->debug_area, DBF_WARNING);
257 	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
258 
259 	device->state = DASD_STATE_BASIC;
260 
261 	return rc;
262 }
263 
264 /*
265  * Release the irq line for the device. Terminate any running i/o.
266  */
267 static int dasd_state_basic_to_known(struct dasd_device *device)
268 {
269 	int rc;
270 
271 	if (device->discipline->basic_to_known) {
272 		rc = device->discipline->basic_to_known(device);
273 		if (rc)
274 			return rc;
275 	}
276 
277 	if (device->block) {
278 		dasd_profile_exit(&device->block->profile);
279 		debugfs_remove(device->block->debugfs_dentry);
280 		dasd_gendisk_free(device->block);
281 		dasd_block_clear_timer(device->block);
282 	}
283 	rc = dasd_flush_device_queue(device);
284 	if (rc)
285 		return rc;
286 	dasd_device_clear_timer(device);
287 	dasd_profile_exit(&device->profile);
288 	dasd_hosts_exit(device);
289 	debugfs_remove(device->debugfs_dentry);
290 	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
291 	if (device->debug_area != NULL) {
292 		debug_unregister(device->debug_area);
293 		device->debug_area = NULL;
294 	}
295 	device->state = DASD_STATE_KNOWN;
296 	return 0;
297 }
298 
299 /*
300  * Do the initial analysis. The do_analysis function may return
301  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
302  * until the discipline decides to continue the startup sequence
303  * by calling the function dasd_change_state. The eckd disciplines
304  * uses this to start a ccw that detects the format. The completion
305  * interrupt for this detection ccw uses the kernel event daemon to
306  * trigger the call to dasd_change_state. All this is done in the
307  * discipline code, see dasd_eckd.c.
308  * After the analysis ccw is done (do_analysis returned 0) the block
309  * device is setup.
310  * In case the analysis returns an error, the device setup is stopped
311  * (a fake disk was already added to allow formatting).
312  */
313 static int dasd_state_basic_to_ready(struct dasd_device *device)
314 {
315 	int rc;
316 	struct dasd_block *block;
317 	struct gendisk *disk;
318 
319 	rc = 0;
320 	block = device->block;
321 	/* make disk known with correct capacity */
322 	if (block) {
323 		if (block->base->discipline->do_analysis != NULL)
324 			rc = block->base->discipline->do_analysis(block);
325 		if (rc) {
326 			if (rc != -EAGAIN) {
327 				device->state = DASD_STATE_UNFMT;
328 				disk = device->block->gdp;
329 				kobject_uevent(&disk_to_dev(disk)->kobj,
330 					       KOBJ_CHANGE);
331 				goto out;
332 			}
333 			return rc;
334 		}
335 		if (device->discipline->setup_blk_queue)
336 			device->discipline->setup_blk_queue(block);
337 		set_capacity(block->gdp,
338 			     block->blocks << block->s2b_shift);
339 		device->state = DASD_STATE_READY;
340 		rc = dasd_scan_partitions(block);
341 		if (rc) {
342 			device->state = DASD_STATE_BASIC;
343 			return rc;
344 		}
345 	} else {
346 		device->state = DASD_STATE_READY;
347 	}
348 out:
349 	if (device->discipline->basic_to_ready)
350 		rc = device->discipline->basic_to_ready(device);
351 	return rc;
352 }
353 
354 static inline
355 int _wait_for_empty_queues(struct dasd_device *device)
356 {
357 	if (device->block)
358 		return list_empty(&device->ccw_queue) &&
359 			list_empty(&device->block->ccw_queue);
360 	else
361 		return list_empty(&device->ccw_queue);
362 }
363 
364 /*
365  * Remove device from block device layer. Destroy dirty buffers.
366  * Forget format information. Check if the target level is basic
367  * and if it is create fake disk for formatting.
368  */
369 static int dasd_state_ready_to_basic(struct dasd_device *device)
370 {
371 	int rc;
372 
373 	device->state = DASD_STATE_BASIC;
374 	if (device->block) {
375 		struct dasd_block *block = device->block;
376 		rc = dasd_flush_block_queue(block);
377 		if (rc) {
378 			device->state = DASD_STATE_READY;
379 			return rc;
380 		}
381 		dasd_destroy_partitions(block);
382 		block->blocks = 0;
383 		block->bp_block = 0;
384 		block->s2b_shift = 0;
385 	}
386 	return 0;
387 }
388 
389 /*
390  * Back to basic.
391  */
392 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
393 {
394 	device->state = DASD_STATE_BASIC;
395 	return 0;
396 }
397 
398 /*
399  * Make the device online and schedule the bottom half to start
400  * the requeueing of requests from the linux request queue to the
401  * ccw queue.
402  */
403 static int
404 dasd_state_ready_to_online(struct dasd_device * device)
405 {
406 	device->state = DASD_STATE_ONLINE;
407 	if (device->block) {
408 		dasd_schedule_block_bh(device->block);
409 		if ((device->features & DASD_FEATURE_USERAW)) {
410 			kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
411 					KOBJ_CHANGE);
412 			return 0;
413 		}
414 		disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
415 	}
416 	return 0;
417 }
418 
419 /*
420  * Stop the requeueing of requests again.
421  */
422 static int dasd_state_online_to_ready(struct dasd_device *device)
423 {
424 	int rc;
425 
426 	if (device->discipline->online_to_ready) {
427 		rc = device->discipline->online_to_ready(device);
428 		if (rc)
429 			return rc;
430 	}
431 
432 	device->state = DASD_STATE_READY;
433 	if (device->block && !(device->features & DASD_FEATURE_USERAW))
434 		disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
435 	return 0;
436 }
437 
438 /*
439  * Device startup state changes.
440  */
441 static int dasd_increase_state(struct dasd_device *device)
442 {
443 	int rc;
444 
445 	rc = 0;
446 	if (device->state == DASD_STATE_NEW &&
447 	    device->target >= DASD_STATE_KNOWN)
448 		rc = dasd_state_new_to_known(device);
449 
450 	if (!rc &&
451 	    device->state == DASD_STATE_KNOWN &&
452 	    device->target >= DASD_STATE_BASIC)
453 		rc = dasd_state_known_to_basic(device);
454 
455 	if (!rc &&
456 	    device->state == DASD_STATE_BASIC &&
457 	    device->target >= DASD_STATE_READY)
458 		rc = dasd_state_basic_to_ready(device);
459 
460 	if (!rc &&
461 	    device->state == DASD_STATE_UNFMT &&
462 	    device->target > DASD_STATE_UNFMT)
463 		rc = -EPERM;
464 
465 	if (!rc &&
466 	    device->state == DASD_STATE_READY &&
467 	    device->target >= DASD_STATE_ONLINE)
468 		rc = dasd_state_ready_to_online(device);
469 
470 	return rc;
471 }
472 
473 /*
474  * Device shutdown state changes.
475  */
476 static int dasd_decrease_state(struct dasd_device *device)
477 {
478 	int rc;
479 
480 	rc = 0;
481 	if (device->state == DASD_STATE_ONLINE &&
482 	    device->target <= DASD_STATE_READY)
483 		rc = dasd_state_online_to_ready(device);
484 
485 	if (!rc &&
486 	    device->state == DASD_STATE_READY &&
487 	    device->target <= DASD_STATE_BASIC)
488 		rc = dasd_state_ready_to_basic(device);
489 
490 	if (!rc &&
491 	    device->state == DASD_STATE_UNFMT &&
492 	    device->target <= DASD_STATE_BASIC)
493 		rc = dasd_state_unfmt_to_basic(device);
494 
495 	if (!rc &&
496 	    device->state == DASD_STATE_BASIC &&
497 	    device->target <= DASD_STATE_KNOWN)
498 		rc = dasd_state_basic_to_known(device);
499 
500 	if (!rc &&
501 	    device->state == DASD_STATE_KNOWN &&
502 	    device->target <= DASD_STATE_NEW)
503 		rc = dasd_state_known_to_new(device);
504 
505 	return rc;
506 }
507 
508 /*
509  * This is the main startup/shutdown routine.
510  */
511 static void dasd_change_state(struct dasd_device *device)
512 {
513 	int rc;
514 
515 	if (device->state == device->target)
516 		/* Already where we want to go today... */
517 		return;
518 	if (device->state < device->target)
519 		rc = dasd_increase_state(device);
520 	else
521 		rc = dasd_decrease_state(device);
522 	if (rc == -EAGAIN)
523 		return;
524 	if (rc)
525 		device->target = device->state;
526 
527 	/* let user-space know that the device status changed */
528 	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
529 
530 	if (device->state == device->target)
531 		wake_up(&dasd_init_waitq);
532 }
533 
534 /*
535  * Kick starter for devices that did not complete the startup/shutdown
536  * procedure or were sleeping because of a pending state.
537  * dasd_kick_device will schedule a call do do_kick_device to the kernel
538  * event daemon.
539  */
540 static void do_kick_device(struct work_struct *work)
541 {
542 	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
543 	mutex_lock(&device->state_mutex);
544 	dasd_change_state(device);
545 	mutex_unlock(&device->state_mutex);
546 	dasd_schedule_device_bh(device);
547 	dasd_put_device(device);
548 }
549 
550 void dasd_kick_device(struct dasd_device *device)
551 {
552 	dasd_get_device(device);
553 	/* queue call to dasd_kick_device to the kernel event daemon. */
554 	if (!schedule_work(&device->kick_work))
555 		dasd_put_device(device);
556 }
557 EXPORT_SYMBOL(dasd_kick_device);
558 
559 /*
560  * dasd_reload_device will schedule a call do do_reload_device to the kernel
561  * event daemon.
562  */
563 static void do_reload_device(struct work_struct *work)
564 {
565 	struct dasd_device *device = container_of(work, struct dasd_device,
566 						  reload_device);
567 	device->discipline->reload(device);
568 	dasd_put_device(device);
569 }
570 
571 void dasd_reload_device(struct dasd_device *device)
572 {
573 	dasd_get_device(device);
574 	/* queue call to dasd_reload_device to the kernel event daemon. */
575 	if (!schedule_work(&device->reload_device))
576 		dasd_put_device(device);
577 }
578 EXPORT_SYMBOL(dasd_reload_device);
579 
580 /*
581  * Set the target state for a device and starts the state change.
582  */
583 void dasd_set_target_state(struct dasd_device *device, int target)
584 {
585 	dasd_get_device(device);
586 	mutex_lock(&device->state_mutex);
587 	/* If we are in probeonly mode stop at DASD_STATE_READY. */
588 	if (dasd_probeonly && target > DASD_STATE_READY)
589 		target = DASD_STATE_READY;
590 	if (device->target != target) {
591 		if (device->state == target)
592 			wake_up(&dasd_init_waitq);
593 		device->target = target;
594 	}
595 	if (device->state != device->target)
596 		dasd_change_state(device);
597 	mutex_unlock(&device->state_mutex);
598 	dasd_put_device(device);
599 }
600 
601 /*
602  * Enable devices with device numbers in [from..to].
603  */
604 static inline int _wait_for_device(struct dasd_device *device)
605 {
606 	return (device->state == device->target);
607 }
608 
609 void dasd_enable_device(struct dasd_device *device)
610 {
611 	dasd_set_target_state(device, DASD_STATE_ONLINE);
612 	if (device->state <= DASD_STATE_KNOWN)
613 		/* No discipline for device found. */
614 		dasd_set_target_state(device, DASD_STATE_NEW);
615 	/* Now wait for the devices to come up. */
616 	wait_event(dasd_init_waitq, _wait_for_device(device));
617 
618 	dasd_reload_device(device);
619 	if (device->discipline->kick_validate)
620 		device->discipline->kick_validate(device);
621 }
622 EXPORT_SYMBOL(dasd_enable_device);
623 
624 /*
625  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
626  */
627 
628 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
629 
630 #ifdef CONFIG_DASD_PROFILE
631 struct dasd_profile dasd_global_profile = {
632 	.lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
633 };
634 static struct dentry *dasd_debugfs_global_entry;
635 
636 /*
637  * Add profiling information for cqr before execution.
638  */
639 static void dasd_profile_start(struct dasd_block *block,
640 			       struct dasd_ccw_req *cqr,
641 			       struct request *req)
642 {
643 	struct list_head *l;
644 	unsigned int counter;
645 	struct dasd_device *device;
646 
647 	/* count the length of the chanq for statistics */
648 	counter = 0;
649 	if (dasd_global_profile_level || block->profile.data)
650 		list_for_each(l, &block->ccw_queue)
651 			if (++counter >= 31)
652 				break;
653 
654 	spin_lock(&dasd_global_profile.lock);
655 	if (dasd_global_profile.data) {
656 		dasd_global_profile.data->dasd_io_nr_req[counter]++;
657 		if (rq_data_dir(req) == READ)
658 			dasd_global_profile.data->dasd_read_nr_req[counter]++;
659 	}
660 	spin_unlock(&dasd_global_profile.lock);
661 
662 	spin_lock(&block->profile.lock);
663 	if (block->profile.data) {
664 		block->profile.data->dasd_io_nr_req[counter]++;
665 		if (rq_data_dir(req) == READ)
666 			block->profile.data->dasd_read_nr_req[counter]++;
667 	}
668 	spin_unlock(&block->profile.lock);
669 
670 	/*
671 	 * We count the request for the start device, even though it may run on
672 	 * some other device due to error recovery. This way we make sure that
673 	 * we count each request only once.
674 	 */
675 	device = cqr->startdev;
676 	if (device->profile.data) {
677 		counter = 1; /* request is not yet queued on the start device */
678 		list_for_each(l, &device->ccw_queue)
679 			if (++counter >= 31)
680 				break;
681 	}
682 	spin_lock(&device->profile.lock);
683 	if (device->profile.data) {
684 		device->profile.data->dasd_io_nr_req[counter]++;
685 		if (rq_data_dir(req) == READ)
686 			device->profile.data->dasd_read_nr_req[counter]++;
687 	}
688 	spin_unlock(&device->profile.lock);
689 }
690 
691 /*
692  * Add profiling information for cqr after execution.
693  */
694 
695 #define dasd_profile_counter(value, index)			   \
696 {								   \
697 	for (index = 0; index < 31 && value >> (2+index); index++) \
698 		;						   \
699 }
700 
701 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
702 				      int is_alias,
703 				      int is_tpm,
704 				      int is_read,
705 				      long sectors,
706 				      int sectors_ind,
707 				      int tottime_ind,
708 				      int tottimeps_ind,
709 				      int strtime_ind,
710 				      int irqtime_ind,
711 				      int irqtimeps_ind,
712 				      int endtime_ind)
713 {
714 	/* in case of an overflow, reset the whole profile */
715 	if (data->dasd_io_reqs == UINT_MAX) {
716 			memset(data, 0, sizeof(*data));
717 			ktime_get_real_ts64(&data->starttod);
718 	}
719 	data->dasd_io_reqs++;
720 	data->dasd_io_sects += sectors;
721 	if (is_alias)
722 		data->dasd_io_alias++;
723 	if (is_tpm)
724 		data->dasd_io_tpm++;
725 
726 	data->dasd_io_secs[sectors_ind]++;
727 	data->dasd_io_times[tottime_ind]++;
728 	data->dasd_io_timps[tottimeps_ind]++;
729 	data->dasd_io_time1[strtime_ind]++;
730 	data->dasd_io_time2[irqtime_ind]++;
731 	data->dasd_io_time2ps[irqtimeps_ind]++;
732 	data->dasd_io_time3[endtime_ind]++;
733 
734 	if (is_read) {
735 		data->dasd_read_reqs++;
736 		data->dasd_read_sects += sectors;
737 		if (is_alias)
738 			data->dasd_read_alias++;
739 		if (is_tpm)
740 			data->dasd_read_tpm++;
741 		data->dasd_read_secs[sectors_ind]++;
742 		data->dasd_read_times[tottime_ind]++;
743 		data->dasd_read_time1[strtime_ind]++;
744 		data->dasd_read_time2[irqtime_ind]++;
745 		data->dasd_read_time3[endtime_ind]++;
746 	}
747 }
748 
749 static void dasd_profile_end(struct dasd_block *block,
750 			     struct dasd_ccw_req *cqr,
751 			     struct request *req)
752 {
753 	unsigned long strtime, irqtime, endtime, tottime;
754 	unsigned long tottimeps, sectors;
755 	struct dasd_device *device;
756 	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
757 	int irqtime_ind, irqtimeps_ind, endtime_ind;
758 	struct dasd_profile_info *data;
759 
760 	device = cqr->startdev;
761 	if (!(dasd_global_profile_level ||
762 	      block->profile.data ||
763 	      device->profile.data))
764 		return;
765 
766 	sectors = blk_rq_sectors(req);
767 	if (!cqr->buildclk || !cqr->startclk ||
768 	    !cqr->stopclk || !cqr->endclk ||
769 	    !sectors)
770 		return;
771 
772 	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
773 	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
774 	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
775 	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
776 	tottimeps = tottime / sectors;
777 
778 	dasd_profile_counter(sectors, sectors_ind);
779 	dasd_profile_counter(tottime, tottime_ind);
780 	dasd_profile_counter(tottimeps, tottimeps_ind);
781 	dasd_profile_counter(strtime, strtime_ind);
782 	dasd_profile_counter(irqtime, irqtime_ind);
783 	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
784 	dasd_profile_counter(endtime, endtime_ind);
785 
786 	spin_lock(&dasd_global_profile.lock);
787 	if (dasd_global_profile.data) {
788 		data = dasd_global_profile.data;
789 		data->dasd_sum_times += tottime;
790 		data->dasd_sum_time_str += strtime;
791 		data->dasd_sum_time_irq += irqtime;
792 		data->dasd_sum_time_end += endtime;
793 		dasd_profile_end_add_data(dasd_global_profile.data,
794 					  cqr->startdev != block->base,
795 					  cqr->cpmode == 1,
796 					  rq_data_dir(req) == READ,
797 					  sectors, sectors_ind, tottime_ind,
798 					  tottimeps_ind, strtime_ind,
799 					  irqtime_ind, irqtimeps_ind,
800 					  endtime_ind);
801 	}
802 	spin_unlock(&dasd_global_profile.lock);
803 
804 	spin_lock(&block->profile.lock);
805 	if (block->profile.data) {
806 		data = block->profile.data;
807 		data->dasd_sum_times += tottime;
808 		data->dasd_sum_time_str += strtime;
809 		data->dasd_sum_time_irq += irqtime;
810 		data->dasd_sum_time_end += endtime;
811 		dasd_profile_end_add_data(block->profile.data,
812 					  cqr->startdev != block->base,
813 					  cqr->cpmode == 1,
814 					  rq_data_dir(req) == READ,
815 					  sectors, sectors_ind, tottime_ind,
816 					  tottimeps_ind, strtime_ind,
817 					  irqtime_ind, irqtimeps_ind,
818 					  endtime_ind);
819 	}
820 	spin_unlock(&block->profile.lock);
821 
822 	spin_lock(&device->profile.lock);
823 	if (device->profile.data) {
824 		data = device->profile.data;
825 		data->dasd_sum_times += tottime;
826 		data->dasd_sum_time_str += strtime;
827 		data->dasd_sum_time_irq += irqtime;
828 		data->dasd_sum_time_end += endtime;
829 		dasd_profile_end_add_data(device->profile.data,
830 					  cqr->startdev != block->base,
831 					  cqr->cpmode == 1,
832 					  rq_data_dir(req) == READ,
833 					  sectors, sectors_ind, tottime_ind,
834 					  tottimeps_ind, strtime_ind,
835 					  irqtime_ind, irqtimeps_ind,
836 					  endtime_ind);
837 	}
838 	spin_unlock(&device->profile.lock);
839 }
840 
841 void dasd_profile_reset(struct dasd_profile *profile)
842 {
843 	struct dasd_profile_info *data;
844 
845 	spin_lock_bh(&profile->lock);
846 	data = profile->data;
847 	if (!data) {
848 		spin_unlock_bh(&profile->lock);
849 		return;
850 	}
851 	memset(data, 0, sizeof(*data));
852 	ktime_get_real_ts64(&data->starttod);
853 	spin_unlock_bh(&profile->lock);
854 }
855 
856 int dasd_profile_on(struct dasd_profile *profile)
857 {
858 	struct dasd_profile_info *data;
859 
860 	data = kzalloc(sizeof(*data), GFP_KERNEL);
861 	if (!data)
862 		return -ENOMEM;
863 	spin_lock_bh(&profile->lock);
864 	if (profile->data) {
865 		spin_unlock_bh(&profile->lock);
866 		kfree(data);
867 		return 0;
868 	}
869 	ktime_get_real_ts64(&data->starttod);
870 	profile->data = data;
871 	spin_unlock_bh(&profile->lock);
872 	return 0;
873 }
874 
875 void dasd_profile_off(struct dasd_profile *profile)
876 {
877 	spin_lock_bh(&profile->lock);
878 	kfree(profile->data);
879 	profile->data = NULL;
880 	spin_unlock_bh(&profile->lock);
881 }
882 
883 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
884 {
885 	char *buffer;
886 
887 	buffer = vmalloc(user_len + 1);
888 	if (buffer == NULL)
889 		return ERR_PTR(-ENOMEM);
890 	if (copy_from_user(buffer, user_buf, user_len) != 0) {
891 		vfree(buffer);
892 		return ERR_PTR(-EFAULT);
893 	}
894 	/* got the string, now strip linefeed. */
895 	if (buffer[user_len - 1] == '\n')
896 		buffer[user_len - 1] = 0;
897 	else
898 		buffer[user_len] = 0;
899 	return buffer;
900 }
901 
902 static ssize_t dasd_stats_write(struct file *file,
903 				const char __user *user_buf,
904 				size_t user_len, loff_t *pos)
905 {
906 	char *buffer, *str;
907 	int rc;
908 	struct seq_file *m = (struct seq_file *)file->private_data;
909 	struct dasd_profile *prof = m->private;
910 
911 	if (user_len > 65536)
912 		user_len = 65536;
913 	buffer = dasd_get_user_string(user_buf, user_len);
914 	if (IS_ERR(buffer))
915 		return PTR_ERR(buffer);
916 
917 	str = skip_spaces(buffer);
918 	rc = user_len;
919 	if (strncmp(str, "reset", 5) == 0) {
920 		dasd_profile_reset(prof);
921 	} else if (strncmp(str, "on", 2) == 0) {
922 		rc = dasd_profile_on(prof);
923 		if (rc)
924 			goto out;
925 		rc = user_len;
926 		if (prof == &dasd_global_profile) {
927 			dasd_profile_reset(prof);
928 			dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
929 		}
930 	} else if (strncmp(str, "off", 3) == 0) {
931 		if (prof == &dasd_global_profile)
932 			dasd_global_profile_level = DASD_PROFILE_OFF;
933 		dasd_profile_off(prof);
934 	} else
935 		rc = -EINVAL;
936 out:
937 	vfree(buffer);
938 	return rc;
939 }
940 
941 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
942 {
943 	int i;
944 
945 	for (i = 0; i < 32; i++)
946 		seq_printf(m, "%u ", array[i]);
947 	seq_putc(m, '\n');
948 }
949 
950 static void dasd_stats_seq_print(struct seq_file *m,
951 				 struct dasd_profile_info *data)
952 {
953 	seq_printf(m, "start_time %lld.%09ld\n",
954 		   (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
955 	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
956 	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
957 	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
958 	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
959 	seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
960 		   data->dasd_sum_times / data->dasd_io_reqs : 0UL);
961 	seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
962 		   data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
963 	seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
964 		   data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
965 	seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
966 		   data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
967 	seq_puts(m, "histogram_sectors ");
968 	dasd_stats_array(m, data->dasd_io_secs);
969 	seq_puts(m, "histogram_io_times ");
970 	dasd_stats_array(m, data->dasd_io_times);
971 	seq_puts(m, "histogram_io_times_weighted ");
972 	dasd_stats_array(m, data->dasd_io_timps);
973 	seq_puts(m, "histogram_time_build_to_ssch ");
974 	dasd_stats_array(m, data->dasd_io_time1);
975 	seq_puts(m, "histogram_time_ssch_to_irq ");
976 	dasd_stats_array(m, data->dasd_io_time2);
977 	seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
978 	dasd_stats_array(m, data->dasd_io_time2ps);
979 	seq_puts(m, "histogram_time_irq_to_end ");
980 	dasd_stats_array(m, data->dasd_io_time3);
981 	seq_puts(m, "histogram_ccw_queue_length ");
982 	dasd_stats_array(m, data->dasd_io_nr_req);
983 	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
984 	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
985 	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
986 	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
987 	seq_puts(m, "histogram_read_sectors ");
988 	dasd_stats_array(m, data->dasd_read_secs);
989 	seq_puts(m, "histogram_read_times ");
990 	dasd_stats_array(m, data->dasd_read_times);
991 	seq_puts(m, "histogram_read_time_build_to_ssch ");
992 	dasd_stats_array(m, data->dasd_read_time1);
993 	seq_puts(m, "histogram_read_time_ssch_to_irq ");
994 	dasd_stats_array(m, data->dasd_read_time2);
995 	seq_puts(m, "histogram_read_time_irq_to_end ");
996 	dasd_stats_array(m, data->dasd_read_time3);
997 	seq_puts(m, "histogram_read_ccw_queue_length ");
998 	dasd_stats_array(m, data->dasd_read_nr_req);
999 }
1000 
1001 static int dasd_stats_show(struct seq_file *m, void *v)
1002 {
1003 	struct dasd_profile *profile;
1004 	struct dasd_profile_info *data;
1005 
1006 	profile = m->private;
1007 	spin_lock_bh(&profile->lock);
1008 	data = profile->data;
1009 	if (!data) {
1010 		spin_unlock_bh(&profile->lock);
1011 		seq_puts(m, "disabled\n");
1012 		return 0;
1013 	}
1014 	dasd_stats_seq_print(m, data);
1015 	spin_unlock_bh(&profile->lock);
1016 	return 0;
1017 }
1018 
1019 static int dasd_stats_open(struct inode *inode, struct file *file)
1020 {
1021 	struct dasd_profile *profile = inode->i_private;
1022 	return single_open(file, dasd_stats_show, profile);
1023 }
1024 
1025 static const struct file_operations dasd_stats_raw_fops = {
1026 	.owner		= THIS_MODULE,
1027 	.open		= dasd_stats_open,
1028 	.read		= seq_read,
1029 	.llseek		= seq_lseek,
1030 	.release	= single_release,
1031 	.write		= dasd_stats_write,
1032 };
1033 
1034 static void dasd_profile_init(struct dasd_profile *profile,
1035 			      struct dentry *base_dentry)
1036 {
1037 	umode_t mode;
1038 	struct dentry *pde;
1039 
1040 	if (!base_dentry)
1041 		return;
1042 	profile->dentry = NULL;
1043 	profile->data = NULL;
1044 	mode = (S_IRUSR | S_IWUSR | S_IFREG);
1045 	pde = debugfs_create_file("statistics", mode, base_dentry,
1046 				  profile, &dasd_stats_raw_fops);
1047 	if (pde && !IS_ERR(pde))
1048 		profile->dentry = pde;
1049 	return;
1050 }
1051 
1052 static void dasd_profile_exit(struct dasd_profile *profile)
1053 {
1054 	dasd_profile_off(profile);
1055 	debugfs_remove(profile->dentry);
1056 	profile->dentry = NULL;
1057 }
1058 
1059 static void dasd_statistics_removeroot(void)
1060 {
1061 	dasd_global_profile_level = DASD_PROFILE_OFF;
1062 	dasd_profile_exit(&dasd_global_profile);
1063 	debugfs_remove(dasd_debugfs_global_entry);
1064 	debugfs_remove(dasd_debugfs_root_entry);
1065 }
1066 
1067 static void dasd_statistics_createroot(void)
1068 {
1069 	struct dentry *pde;
1070 
1071 	dasd_debugfs_root_entry = NULL;
1072 	pde = debugfs_create_dir("dasd", NULL);
1073 	if (!pde || IS_ERR(pde))
1074 		goto error;
1075 	dasd_debugfs_root_entry = pde;
1076 	pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1077 	if (!pde || IS_ERR(pde))
1078 		goto error;
1079 	dasd_debugfs_global_entry = pde;
1080 	dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1081 	return;
1082 
1083 error:
1084 	DBF_EVENT(DBF_ERR, "%s",
1085 		  "Creation of the dasd debugfs interface failed");
1086 	dasd_statistics_removeroot();
1087 	return;
1088 }
1089 
1090 #else
1091 #define dasd_profile_start(block, cqr, req) do {} while (0)
1092 #define dasd_profile_end(block, cqr, req) do {} while (0)
1093 
1094 static void dasd_statistics_createroot(void)
1095 {
1096 	return;
1097 }
1098 
1099 static void dasd_statistics_removeroot(void)
1100 {
1101 	return;
1102 }
1103 
1104 int dasd_stats_generic_show(struct seq_file *m, void *v)
1105 {
1106 	seq_puts(m, "Statistics are not activated in this kernel\n");
1107 	return 0;
1108 }
1109 
1110 static void dasd_profile_init(struct dasd_profile *profile,
1111 			      struct dentry *base_dentry)
1112 {
1113 	return;
1114 }
1115 
1116 static void dasd_profile_exit(struct dasd_profile *profile)
1117 {
1118 	return;
1119 }
1120 
1121 int dasd_profile_on(struct dasd_profile *profile)
1122 {
1123 	return 0;
1124 }
1125 
1126 #endif				/* CONFIG_DASD_PROFILE */
1127 
1128 static int dasd_hosts_show(struct seq_file *m, void *v)
1129 {
1130 	struct dasd_device *device;
1131 	int rc = -EOPNOTSUPP;
1132 
1133 	device = m->private;
1134 	dasd_get_device(device);
1135 
1136 	if (device->discipline->hosts_print)
1137 		rc = device->discipline->hosts_print(device, m);
1138 
1139 	dasd_put_device(device);
1140 	return rc;
1141 }
1142 
1143 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1144 
1145 static void dasd_hosts_exit(struct dasd_device *device)
1146 {
1147 	debugfs_remove(device->hosts_dentry);
1148 	device->hosts_dentry = NULL;
1149 }
1150 
1151 static void dasd_hosts_init(struct dentry *base_dentry,
1152 			    struct dasd_device *device)
1153 {
1154 	struct dentry *pde;
1155 	umode_t mode;
1156 
1157 	if (!base_dentry)
1158 		return;
1159 
1160 	mode = S_IRUSR | S_IFREG;
1161 	pde = debugfs_create_file("host_access_list", mode, base_dentry,
1162 				  device, &dasd_hosts_fops);
1163 	if (pde && !IS_ERR(pde))
1164 		device->hosts_dentry = pde;
1165 }
1166 
1167 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1168 					  struct dasd_device *device,
1169 					  struct dasd_ccw_req *cqr)
1170 {
1171 	unsigned long flags;
1172 	char *data, *chunk;
1173 	int size = 0;
1174 
1175 	if (cplength > 0)
1176 		size += cplength * sizeof(struct ccw1);
1177 	if (datasize > 0)
1178 		size += datasize;
1179 	if (!cqr)
1180 		size += (sizeof(*cqr) + 7L) & -8L;
1181 
1182 	spin_lock_irqsave(&device->mem_lock, flags);
1183 	data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1184 	spin_unlock_irqrestore(&device->mem_lock, flags);
1185 	if (!chunk)
1186 		return ERR_PTR(-ENOMEM);
1187 	if (!cqr) {
1188 		cqr = (void *) data;
1189 		data += (sizeof(*cqr) + 7L) & -8L;
1190 	}
1191 	memset(cqr, 0, sizeof(*cqr));
1192 	cqr->mem_chunk = chunk;
1193 	if (cplength > 0) {
1194 		cqr->cpaddr = data;
1195 		data += cplength * sizeof(struct ccw1);
1196 		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1197 	}
1198 	if (datasize > 0) {
1199 		cqr->data = data;
1200  		memset(cqr->data, 0, datasize);
1201 	}
1202 	cqr->magic = magic;
1203 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1204 	dasd_get_device(device);
1205 	return cqr;
1206 }
1207 EXPORT_SYMBOL(dasd_smalloc_request);
1208 
1209 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1210 					  int datasize,
1211 					  struct dasd_device *device)
1212 {
1213 	struct dasd_ccw_req *cqr;
1214 	unsigned long flags;
1215 	int size, cqr_size;
1216 	char *data;
1217 
1218 	cqr_size = (sizeof(*cqr) + 7L) & -8L;
1219 	size = cqr_size;
1220 	if (cplength > 0)
1221 		size += cplength * sizeof(struct ccw1);
1222 	if (datasize > 0)
1223 		size += datasize;
1224 
1225 	spin_lock_irqsave(&device->mem_lock, flags);
1226 	cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1227 	spin_unlock_irqrestore(&device->mem_lock, flags);
1228 	if (!cqr)
1229 		return ERR_PTR(-ENOMEM);
1230 	memset(cqr, 0, sizeof(*cqr));
1231 	data = (char *)cqr + cqr_size;
1232 	cqr->cpaddr = NULL;
1233 	if (cplength > 0) {
1234 		cqr->cpaddr = data;
1235 		data += cplength * sizeof(struct ccw1);
1236 		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1237 	}
1238 	cqr->data = NULL;
1239 	if (datasize > 0) {
1240 		cqr->data = data;
1241 		memset(cqr->data, 0, datasize);
1242 	}
1243 
1244 	cqr->magic = magic;
1245 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1246 	dasd_get_device(device);
1247 
1248 	return cqr;
1249 }
1250 EXPORT_SYMBOL(dasd_fmalloc_request);
1251 
1252 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1253 {
1254 	unsigned long flags;
1255 
1256 	spin_lock_irqsave(&device->mem_lock, flags);
1257 	dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1258 	spin_unlock_irqrestore(&device->mem_lock, flags);
1259 	dasd_put_device(device);
1260 }
1261 EXPORT_SYMBOL(dasd_sfree_request);
1262 
1263 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1264 {
1265 	unsigned long flags;
1266 
1267 	spin_lock_irqsave(&device->mem_lock, flags);
1268 	dasd_free_chunk(&device->ese_chunks, cqr);
1269 	spin_unlock_irqrestore(&device->mem_lock, flags);
1270 	dasd_put_device(device);
1271 }
1272 EXPORT_SYMBOL(dasd_ffree_request);
1273 
1274 /*
1275  * Check discipline magic in cqr.
1276  */
1277 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1278 {
1279 	struct dasd_device *device;
1280 
1281 	if (cqr == NULL)
1282 		return -EINVAL;
1283 	device = cqr->startdev;
1284 	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1285 		DBF_DEV_EVENT(DBF_WARNING, device,
1286 			    " dasd_ccw_req 0x%08x magic doesn't match"
1287 			    " discipline 0x%08x",
1288 			    cqr->magic,
1289 			    *(unsigned int *) device->discipline->name);
1290 		return -EINVAL;
1291 	}
1292 	return 0;
1293 }
1294 
1295 /*
1296  * Terminate the current i/o and set the request to clear_pending.
1297  * Timer keeps device runnig.
1298  * ccw_device_clear can fail if the i/o subsystem
1299  * is in a bad mood.
1300  */
1301 int dasd_term_IO(struct dasd_ccw_req *cqr)
1302 {
1303 	struct dasd_device *device;
1304 	int retries, rc;
1305 	char errorstring[ERRORLENGTH];
1306 
1307 	/* Check the cqr */
1308 	rc = dasd_check_cqr(cqr);
1309 	if (rc)
1310 		return rc;
1311 	retries = 0;
1312 	device = (struct dasd_device *) cqr->startdev;
1313 	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1314 		rc = ccw_device_clear(device->cdev, (long) cqr);
1315 		switch (rc) {
1316 		case 0:	/* termination successful */
1317 			cqr->status = DASD_CQR_CLEAR_PENDING;
1318 			cqr->stopclk = get_tod_clock();
1319 			cqr->starttime = 0;
1320 			DBF_DEV_EVENT(DBF_DEBUG, device,
1321 				      "terminate cqr %p successful",
1322 				      cqr);
1323 			break;
1324 		case -ENODEV:
1325 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1326 				      "device gone, retry");
1327 			break;
1328 		case -EINVAL:
1329 			/*
1330 			 * device not valid so no I/O could be running
1331 			 * handle CQR as termination successful
1332 			 */
1333 			cqr->status = DASD_CQR_CLEARED;
1334 			cqr->stopclk = get_tod_clock();
1335 			cqr->starttime = 0;
1336 			/* no retries for invalid devices */
1337 			cqr->retries = -1;
1338 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1339 				      "EINVAL, handle as terminated");
1340 			/* fake rc to success */
1341 			rc = 0;
1342 			break;
1343 		default:
1344 			/* internal error 10 - unknown rc*/
1345 			snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1346 			dev_err(&device->cdev->dev, "An error occurred in the "
1347 				"DASD device driver, reason=%s\n", errorstring);
1348 			BUG();
1349 			break;
1350 		}
1351 		retries++;
1352 	}
1353 	dasd_schedule_device_bh(device);
1354 	return rc;
1355 }
1356 EXPORT_SYMBOL(dasd_term_IO);
1357 
1358 /*
1359  * Start the i/o. This start_IO can fail if the channel is really busy.
1360  * In that case set up a timer to start the request later.
1361  */
1362 int dasd_start_IO(struct dasd_ccw_req *cqr)
1363 {
1364 	struct dasd_device *device;
1365 	int rc;
1366 	char errorstring[ERRORLENGTH];
1367 
1368 	/* Check the cqr */
1369 	rc = dasd_check_cqr(cqr);
1370 	if (rc) {
1371 		cqr->intrc = rc;
1372 		return rc;
1373 	}
1374 	device = (struct dasd_device *) cqr->startdev;
1375 	if (((cqr->block &&
1376 	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1377 	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1378 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1379 		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1380 			      "because of stolen lock", cqr);
1381 		cqr->status = DASD_CQR_ERROR;
1382 		cqr->intrc = -EPERM;
1383 		return -EPERM;
1384 	}
1385 	if (cqr->retries < 0) {
1386 		/* internal error 14 - start_IO run out of retries */
1387 		sprintf(errorstring, "14 %p", cqr);
1388 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1389 			"device driver, reason=%s\n", errorstring);
1390 		cqr->status = DASD_CQR_ERROR;
1391 		return -EIO;
1392 	}
1393 	cqr->startclk = get_tod_clock();
1394 	cqr->starttime = jiffies;
1395 	cqr->retries--;
1396 	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1397 		cqr->lpm &= dasd_path_get_opm(device);
1398 		if (!cqr->lpm)
1399 			cqr->lpm = dasd_path_get_opm(device);
1400 	}
1401 	/*
1402 	 * remember the amount of formatted tracks to prevent double format on
1403 	 * ESE devices
1404 	 */
1405 	if (cqr->block)
1406 		cqr->trkcount = atomic_read(&cqr->block->trkcount);
1407 
1408 	if (cqr->cpmode == 1) {
1409 		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1410 					 (long) cqr, cqr->lpm);
1411 	} else {
1412 		rc = ccw_device_start(device->cdev, cqr->cpaddr,
1413 				      (long) cqr, cqr->lpm, 0);
1414 	}
1415 	switch (rc) {
1416 	case 0:
1417 		cqr->status = DASD_CQR_IN_IO;
1418 		break;
1419 	case -EBUSY:
1420 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1421 			      "start_IO: device busy, retry later");
1422 		break;
1423 	case -EACCES:
1424 		/* -EACCES indicates that the request used only a subset of the
1425 		 * available paths and all these paths are gone. If the lpm of
1426 		 * this request was only a subset of the opm (e.g. the ppm) then
1427 		 * we just do a retry with all available paths.
1428 		 * If we already use the full opm, something is amiss, and we
1429 		 * need a full path verification.
1430 		 */
1431 		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1432 			DBF_DEV_EVENT(DBF_WARNING, device,
1433 				      "start_IO: selected paths gone (%x)",
1434 				      cqr->lpm);
1435 		} else if (cqr->lpm != dasd_path_get_opm(device)) {
1436 			cqr->lpm = dasd_path_get_opm(device);
1437 			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1438 				      "start_IO: selected paths gone,"
1439 				      " retry on all paths");
1440 		} else {
1441 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1442 				      "start_IO: all paths in opm gone,"
1443 				      " do path verification");
1444 			dasd_generic_last_path_gone(device);
1445 			dasd_path_no_path(device);
1446 			dasd_path_set_tbvpm(device,
1447 					  ccw_device_get_path_mask(
1448 						  device->cdev));
1449 		}
1450 		break;
1451 	case -ENODEV:
1452 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1453 			      "start_IO: -ENODEV device gone, retry");
1454 		break;
1455 	case -EIO:
1456 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1457 			      "start_IO: -EIO device gone, retry");
1458 		break;
1459 	case -EINVAL:
1460 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1461 			      "start_IO: -EINVAL device currently "
1462 			      "not accessible");
1463 		break;
1464 	default:
1465 		/* internal error 11 - unknown rc */
1466 		snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1467 		dev_err(&device->cdev->dev,
1468 			"An error occurred in the DASD device driver, "
1469 			"reason=%s\n", errorstring);
1470 		BUG();
1471 		break;
1472 	}
1473 	cqr->intrc = rc;
1474 	return rc;
1475 }
1476 EXPORT_SYMBOL(dasd_start_IO);
1477 
1478 /*
1479  * Timeout function for dasd devices. This is used for different purposes
1480  *  1) missing interrupt handler for normal operation
1481  *  2) delayed start of request where start_IO failed with -EBUSY
1482  *  3) timeout for missing state change interrupts
1483  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1484  * DASD_CQR_QUEUED for 2) and 3).
1485  */
1486 static void dasd_device_timeout(struct timer_list *t)
1487 {
1488 	unsigned long flags;
1489 	struct dasd_device *device;
1490 
1491 	device = from_timer(device, t, timer);
1492 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1493 	/* re-activate request queue */
1494 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1495 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1496 	dasd_schedule_device_bh(device);
1497 }
1498 
1499 /*
1500  * Setup timeout for a device in jiffies.
1501  */
1502 void dasd_device_set_timer(struct dasd_device *device, int expires)
1503 {
1504 	if (expires == 0)
1505 		del_timer(&device->timer);
1506 	else
1507 		mod_timer(&device->timer, jiffies + expires);
1508 }
1509 EXPORT_SYMBOL(dasd_device_set_timer);
1510 
1511 /*
1512  * Clear timeout for a device.
1513  */
1514 void dasd_device_clear_timer(struct dasd_device *device)
1515 {
1516 	del_timer(&device->timer);
1517 }
1518 EXPORT_SYMBOL(dasd_device_clear_timer);
1519 
1520 static void dasd_handle_killed_request(struct ccw_device *cdev,
1521 				       unsigned long intparm)
1522 {
1523 	struct dasd_ccw_req *cqr;
1524 	struct dasd_device *device;
1525 
1526 	if (!intparm)
1527 		return;
1528 	cqr = (struct dasd_ccw_req *) intparm;
1529 	if (cqr->status != DASD_CQR_IN_IO) {
1530 		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1531 				"invalid status in handle_killed_request: "
1532 				"%02x", cqr->status);
1533 		return;
1534 	}
1535 
1536 	device = dasd_device_from_cdev_locked(cdev);
1537 	if (IS_ERR(device)) {
1538 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1539 				"unable to get device from cdev");
1540 		return;
1541 	}
1542 
1543 	if (!cqr->startdev ||
1544 	    device != cqr->startdev ||
1545 	    strncmp(cqr->startdev->discipline->ebcname,
1546 		    (char *) &cqr->magic, 4)) {
1547 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1548 				"invalid device in request");
1549 		dasd_put_device(device);
1550 		return;
1551 	}
1552 
1553 	/* Schedule request to be retried. */
1554 	cqr->status = DASD_CQR_QUEUED;
1555 
1556 	dasd_device_clear_timer(device);
1557 	dasd_schedule_device_bh(device);
1558 	dasd_put_device(device);
1559 }
1560 
1561 void dasd_generic_handle_state_change(struct dasd_device *device)
1562 {
1563 	/* First of all start sense subsystem status request. */
1564 	dasd_eer_snss(device);
1565 
1566 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1567 	dasd_schedule_device_bh(device);
1568 	if (device->block) {
1569 		dasd_schedule_block_bh(device->block);
1570 		if (device->block->gdp)
1571 			blk_mq_run_hw_queues(device->block->gdp->queue, true);
1572 	}
1573 }
1574 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1575 
1576 static int dasd_check_hpf_error(struct irb *irb)
1577 {
1578 	return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1579 	    (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1580 	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1581 }
1582 
1583 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1584 {
1585 	struct dasd_device *device = NULL;
1586 	u8 *sense = NULL;
1587 
1588 	if (!block)
1589 		return 0;
1590 	device = block->base;
1591 	if (!device || !device->discipline->is_ese)
1592 		return 0;
1593 	if (!device->discipline->is_ese(device))
1594 		return 0;
1595 
1596 	sense = dasd_get_sense(irb);
1597 	if (!sense)
1598 		return 0;
1599 
1600 	return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1601 		!!(sense[1] & SNS1_FILE_PROTECTED) ||
1602 		scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1603 }
1604 
1605 static int dasd_ese_oos_cond(u8 *sense)
1606 {
1607 	return sense[0] & SNS0_EQUIPMENT_CHECK &&
1608 		sense[1] & SNS1_PERM_ERR &&
1609 		sense[1] & SNS1_WRITE_INHIBITED &&
1610 		sense[25] == 0x01;
1611 }
1612 
1613 /*
1614  * Interrupt handler for "normal" ssch-io based dasd devices.
1615  */
1616 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1617 		      struct irb *irb)
1618 {
1619 	struct dasd_ccw_req *cqr, *next, *fcqr;
1620 	struct dasd_device *device;
1621 	unsigned long now;
1622 	int nrf_suppressed = 0;
1623 	int fp_suppressed = 0;
1624 	struct request *req;
1625 	u8 *sense = NULL;
1626 	int expires;
1627 
1628 	cqr = (struct dasd_ccw_req *) intparm;
1629 	if (IS_ERR(irb)) {
1630 		switch (PTR_ERR(irb)) {
1631 		case -EIO:
1632 			if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1633 				device = cqr->startdev;
1634 				cqr->status = DASD_CQR_CLEARED;
1635 				dasd_device_clear_timer(device);
1636 				wake_up(&dasd_flush_wq);
1637 				dasd_schedule_device_bh(device);
1638 				return;
1639 			}
1640 			break;
1641 		case -ETIMEDOUT:
1642 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1643 					"request timed out\n", __func__);
1644 			break;
1645 		default:
1646 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1647 					"unknown error %ld\n", __func__,
1648 					PTR_ERR(irb));
1649 		}
1650 		dasd_handle_killed_request(cdev, intparm);
1651 		return;
1652 	}
1653 
1654 	now = get_tod_clock();
1655 	/* check for conditions that should be handled immediately */
1656 	if (!cqr ||
1657 	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1658 	      scsw_cstat(&irb->scsw) == 0)) {
1659 		if (cqr)
1660 			memcpy(&cqr->irb, irb, sizeof(*irb));
1661 		device = dasd_device_from_cdev_locked(cdev);
1662 		if (IS_ERR(device))
1663 			return;
1664 		/* ignore unsolicited interrupts for DIAG discipline */
1665 		if (device->discipline == dasd_diag_discipline_pointer) {
1666 			dasd_put_device(device);
1667 			return;
1668 		}
1669 
1670 		/*
1671 		 * In some cases 'File Protected' or 'No Record Found' errors
1672 		 * might be expected and debug log messages for the
1673 		 * corresponding interrupts shouldn't be written then.
1674 		 * Check if either of the according suppress bits is set.
1675 		 */
1676 		sense = dasd_get_sense(irb);
1677 		if (sense) {
1678 			fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1679 				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1680 			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1681 				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1682 
1683 			/*
1684 			 * Extent pool probably out-of-space.
1685 			 * Stop device and check exhaust level.
1686 			 */
1687 			if (dasd_ese_oos_cond(sense)) {
1688 				dasd_generic_space_exhaust(device, cqr);
1689 				device->discipline->ext_pool_exhaust(device, cqr);
1690 				dasd_put_device(device);
1691 				return;
1692 			}
1693 		}
1694 		if (!(fp_suppressed || nrf_suppressed))
1695 			device->discipline->dump_sense_dbf(device, irb, "int");
1696 
1697 		if (device->features & DASD_FEATURE_ERPLOG)
1698 			device->discipline->dump_sense(device, cqr, irb);
1699 		device->discipline->check_for_device_change(device, cqr, irb);
1700 		dasd_put_device(device);
1701 	}
1702 
1703 	/* check for attention message */
1704 	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1705 		device = dasd_device_from_cdev_locked(cdev);
1706 		if (!IS_ERR(device)) {
1707 			device->discipline->check_attention(device,
1708 							    irb->esw.esw1.lpum);
1709 			dasd_put_device(device);
1710 		}
1711 	}
1712 
1713 	if (!cqr)
1714 		return;
1715 
1716 	device = (struct dasd_device *) cqr->startdev;
1717 	if (!device ||
1718 	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1719 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1720 				"invalid device in request");
1721 		return;
1722 	}
1723 
1724 	if (dasd_ese_needs_format(cqr->block, irb)) {
1725 		req = dasd_get_callback_data(cqr);
1726 		if (!req) {
1727 			cqr->status = DASD_CQR_ERROR;
1728 			return;
1729 		}
1730 		if (rq_data_dir(req) == READ) {
1731 			device->discipline->ese_read(cqr, irb);
1732 			cqr->status = DASD_CQR_SUCCESS;
1733 			cqr->stopclk = now;
1734 			dasd_device_clear_timer(device);
1735 			dasd_schedule_device_bh(device);
1736 			return;
1737 		}
1738 		fcqr = device->discipline->ese_format(device, cqr, irb);
1739 		if (IS_ERR(fcqr)) {
1740 			if (PTR_ERR(fcqr) == -EINVAL) {
1741 				cqr->status = DASD_CQR_ERROR;
1742 				return;
1743 			}
1744 			/*
1745 			 * If we can't format now, let the request go
1746 			 * one extra round. Maybe we can format later.
1747 			 */
1748 			cqr->status = DASD_CQR_QUEUED;
1749 			dasd_schedule_device_bh(device);
1750 			return;
1751 		} else {
1752 			fcqr->status = DASD_CQR_QUEUED;
1753 			cqr->status = DASD_CQR_QUEUED;
1754 			list_add(&fcqr->devlist, &device->ccw_queue);
1755 			dasd_schedule_device_bh(device);
1756 			return;
1757 		}
1758 	}
1759 
1760 	/* Check for clear pending */
1761 	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1762 	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1763 		cqr->status = DASD_CQR_CLEARED;
1764 		dasd_device_clear_timer(device);
1765 		wake_up(&dasd_flush_wq);
1766 		dasd_schedule_device_bh(device);
1767 		return;
1768 	}
1769 
1770 	/* check status - the request might have been killed by dyn detach */
1771 	if (cqr->status != DASD_CQR_IN_IO) {
1772 		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1773 			      "status %02x", dev_name(&cdev->dev), cqr->status);
1774 		return;
1775 	}
1776 
1777 	next = NULL;
1778 	expires = 0;
1779 	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1780 	    scsw_cstat(&irb->scsw) == 0) {
1781 		/* request was completed successfully */
1782 		cqr->status = DASD_CQR_SUCCESS;
1783 		cqr->stopclk = now;
1784 		/* Start first request on queue if possible -> fast_io. */
1785 		if (cqr->devlist.next != &device->ccw_queue) {
1786 			next = list_entry(cqr->devlist.next,
1787 					  struct dasd_ccw_req, devlist);
1788 		}
1789 	} else {  /* error */
1790 		/* check for HPF error
1791 		 * call discipline function to requeue all requests
1792 		 * and disable HPF accordingly
1793 		 */
1794 		if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1795 		    device->discipline->handle_hpf_error)
1796 			device->discipline->handle_hpf_error(device, irb);
1797 		/*
1798 		 * If we don't want complex ERP for this request, then just
1799 		 * reset this and retry it in the fastpath
1800 		 */
1801 		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1802 		    cqr->retries > 0) {
1803 			if (cqr->lpm == dasd_path_get_opm(device))
1804 				DBF_DEV_EVENT(DBF_DEBUG, device,
1805 					      "default ERP in fastpath "
1806 					      "(%i retries left)",
1807 					      cqr->retries);
1808 			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1809 				cqr->lpm = dasd_path_get_opm(device);
1810 			cqr->status = DASD_CQR_QUEUED;
1811 			next = cqr;
1812 		} else
1813 			cqr->status = DASD_CQR_ERROR;
1814 	}
1815 	if (next && (next->status == DASD_CQR_QUEUED) &&
1816 	    (!device->stopped)) {
1817 		if (device->discipline->start_IO(next) == 0)
1818 			expires = next->expires;
1819 	}
1820 	if (expires != 0)
1821 		dasd_device_set_timer(device, expires);
1822 	else
1823 		dasd_device_clear_timer(device);
1824 	dasd_schedule_device_bh(device);
1825 }
1826 EXPORT_SYMBOL(dasd_int_handler);
1827 
1828 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1829 {
1830 	struct dasd_device *device;
1831 
1832 	device = dasd_device_from_cdev_locked(cdev);
1833 
1834 	if (IS_ERR(device))
1835 		goto out;
1836 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1837 	   device->state != device->target ||
1838 	   !device->discipline->check_for_device_change){
1839 		dasd_put_device(device);
1840 		goto out;
1841 	}
1842 	if (device->discipline->dump_sense_dbf)
1843 		device->discipline->dump_sense_dbf(device, irb, "uc");
1844 	device->discipline->check_for_device_change(device, NULL, irb);
1845 	dasd_put_device(device);
1846 out:
1847 	return UC_TODO_RETRY;
1848 }
1849 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1850 
1851 /*
1852  * If we have an error on a dasd_block layer request then we cancel
1853  * and return all further requests from the same dasd_block as well.
1854  */
1855 static void __dasd_device_recovery(struct dasd_device *device,
1856 				   struct dasd_ccw_req *ref_cqr)
1857 {
1858 	struct list_head *l, *n;
1859 	struct dasd_ccw_req *cqr;
1860 
1861 	/*
1862 	 * only requeue request that came from the dasd_block layer
1863 	 */
1864 	if (!ref_cqr->block)
1865 		return;
1866 
1867 	list_for_each_safe(l, n, &device->ccw_queue) {
1868 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1869 		if (cqr->status == DASD_CQR_QUEUED &&
1870 		    ref_cqr->block == cqr->block) {
1871 			cqr->status = DASD_CQR_CLEARED;
1872 		}
1873 	}
1874 };
1875 
1876 /*
1877  * Remove those ccw requests from the queue that need to be returned
1878  * to the upper layer.
1879  */
1880 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1881 					    struct list_head *final_queue)
1882 {
1883 	struct list_head *l, *n;
1884 	struct dasd_ccw_req *cqr;
1885 
1886 	/* Process request with final status. */
1887 	list_for_each_safe(l, n, &device->ccw_queue) {
1888 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1889 
1890 		/* Skip any non-final request. */
1891 		if (cqr->status == DASD_CQR_QUEUED ||
1892 		    cqr->status == DASD_CQR_IN_IO ||
1893 		    cqr->status == DASD_CQR_CLEAR_PENDING)
1894 			continue;
1895 		if (cqr->status == DASD_CQR_ERROR) {
1896 			__dasd_device_recovery(device, cqr);
1897 		}
1898 		/* Rechain finished requests to final queue */
1899 		list_move_tail(&cqr->devlist, final_queue);
1900 	}
1901 }
1902 
1903 static void __dasd_process_cqr(struct dasd_device *device,
1904 			       struct dasd_ccw_req *cqr)
1905 {
1906 	char errorstring[ERRORLENGTH];
1907 
1908 	switch (cqr->status) {
1909 	case DASD_CQR_SUCCESS:
1910 		cqr->status = DASD_CQR_DONE;
1911 		break;
1912 	case DASD_CQR_ERROR:
1913 		cqr->status = DASD_CQR_NEED_ERP;
1914 		break;
1915 	case DASD_CQR_CLEARED:
1916 		cqr->status = DASD_CQR_TERMINATED;
1917 		break;
1918 	default:
1919 		/* internal error 12 - wrong cqr status*/
1920 		snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1921 		dev_err(&device->cdev->dev,
1922 			"An error occurred in the DASD device driver, "
1923 			"reason=%s\n", errorstring);
1924 		BUG();
1925 	}
1926 	if (cqr->callback)
1927 		cqr->callback(cqr, cqr->callback_data);
1928 }
1929 
1930 /*
1931  * the cqrs from the final queue are returned to the upper layer
1932  * by setting a dasd_block state and calling the callback function
1933  */
1934 static void __dasd_device_process_final_queue(struct dasd_device *device,
1935 					      struct list_head *final_queue)
1936 {
1937 	struct list_head *l, *n;
1938 	struct dasd_ccw_req *cqr;
1939 	struct dasd_block *block;
1940 
1941 	list_for_each_safe(l, n, final_queue) {
1942 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1943 		list_del_init(&cqr->devlist);
1944 		block = cqr->block;
1945 		if (!block) {
1946 			__dasd_process_cqr(device, cqr);
1947 		} else {
1948 			spin_lock_bh(&block->queue_lock);
1949 			__dasd_process_cqr(device, cqr);
1950 			spin_unlock_bh(&block->queue_lock);
1951 		}
1952 	}
1953 }
1954 
1955 /*
1956  * Take a look at the first request on the ccw queue and check
1957  * if it reached its expire time. If so, terminate the IO.
1958  */
1959 static void __dasd_device_check_expire(struct dasd_device *device)
1960 {
1961 	struct dasd_ccw_req *cqr;
1962 
1963 	if (list_empty(&device->ccw_queue))
1964 		return;
1965 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1966 	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1967 	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1968 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1969 			/*
1970 			 * IO in safe offline processing should not
1971 			 * run out of retries
1972 			 */
1973 			cqr->retries++;
1974 		}
1975 		if (device->discipline->term_IO(cqr) != 0) {
1976 			/* Hmpf, try again in 5 sec */
1977 			dev_err(&device->cdev->dev,
1978 				"cqr %p timed out (%lus) but cannot be "
1979 				"ended, retrying in 5 s\n",
1980 				cqr, (cqr->expires/HZ));
1981 			cqr->expires += 5*HZ;
1982 			dasd_device_set_timer(device, 5*HZ);
1983 		} else {
1984 			dev_err(&device->cdev->dev,
1985 				"cqr %p timed out (%lus), %i retries "
1986 				"remaining\n", cqr, (cqr->expires/HZ),
1987 				cqr->retries);
1988 		}
1989 	}
1990 }
1991 
1992 /*
1993  * return 1 when device is not eligible for IO
1994  */
1995 static int __dasd_device_is_unusable(struct dasd_device *device,
1996 				     struct dasd_ccw_req *cqr)
1997 {
1998 	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
1999 
2000 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2001 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2002 		/*
2003 		 * dasd is being set offline
2004 		 * but it is no safe offline where we have to allow I/O
2005 		 */
2006 		return 1;
2007 	}
2008 	if (device->stopped) {
2009 		if (device->stopped & mask) {
2010 			/* stopped and CQR will not change that. */
2011 			return 1;
2012 		}
2013 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2014 			/* CQR is not able to change device to
2015 			 * operational. */
2016 			return 1;
2017 		}
2018 		/* CQR required to get device operational. */
2019 	}
2020 	return 0;
2021 }
2022 
2023 /*
2024  * Take a look at the first request on the ccw queue and check
2025  * if it needs to be started.
2026  */
2027 static void __dasd_device_start_head(struct dasd_device *device)
2028 {
2029 	struct dasd_ccw_req *cqr;
2030 	int rc;
2031 
2032 	if (list_empty(&device->ccw_queue))
2033 		return;
2034 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2035 	if (cqr->status != DASD_CQR_QUEUED)
2036 		return;
2037 	/* if device is not usable return request to upper layer */
2038 	if (__dasd_device_is_unusable(device, cqr)) {
2039 		cqr->intrc = -EAGAIN;
2040 		cqr->status = DASD_CQR_CLEARED;
2041 		dasd_schedule_device_bh(device);
2042 		return;
2043 	}
2044 
2045 	rc = device->discipline->start_IO(cqr);
2046 	if (rc == 0)
2047 		dasd_device_set_timer(device, cqr->expires);
2048 	else if (rc == -EACCES) {
2049 		dasd_schedule_device_bh(device);
2050 	} else
2051 		/* Hmpf, try again in 1/2 sec */
2052 		dasd_device_set_timer(device, 50);
2053 }
2054 
2055 static void __dasd_device_check_path_events(struct dasd_device *device)
2056 {
2057 	__u8 tbvpm, fcsecpm;
2058 	int rc;
2059 
2060 	tbvpm = dasd_path_get_tbvpm(device);
2061 	fcsecpm = dasd_path_get_fcsecpm(device);
2062 
2063 	if (!tbvpm && !fcsecpm)
2064 		return;
2065 
2066 	if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
2067 		return;
2068 
2069 	dasd_path_clear_all_verify(device);
2070 	dasd_path_clear_all_fcsec(device);
2071 
2072 	rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);
2073 	if (rc) {
2074 		dasd_path_add_tbvpm(device, tbvpm);
2075 		dasd_path_add_fcsecpm(device, fcsecpm);
2076 		dasd_device_set_timer(device, 50);
2077 	}
2078 };
2079 
2080 /*
2081  * Go through all request on the dasd_device request queue,
2082  * terminate them on the cdev if necessary, and return them to the
2083  * submitting layer via callback.
2084  * Note:
2085  * Make sure that all 'submitting layers' still exist when
2086  * this function is called!. In other words, when 'device' is a base
2087  * device then all block layer requests must have been removed before
2088  * via dasd_flush_block_queue.
2089  */
2090 int dasd_flush_device_queue(struct dasd_device *device)
2091 {
2092 	struct dasd_ccw_req *cqr, *n;
2093 	int rc;
2094 	struct list_head flush_queue;
2095 
2096 	INIT_LIST_HEAD(&flush_queue);
2097 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2098 	rc = 0;
2099 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2100 		/* Check status and move request to flush_queue */
2101 		switch (cqr->status) {
2102 		case DASD_CQR_IN_IO:
2103 			rc = device->discipline->term_IO(cqr);
2104 			if (rc) {
2105 				/* unable to terminate requeust */
2106 				dev_err(&device->cdev->dev,
2107 					"Flushing the DASD request queue "
2108 					"failed for request %p\n", cqr);
2109 				/* stop flush processing */
2110 				goto finished;
2111 			}
2112 			break;
2113 		case DASD_CQR_QUEUED:
2114 			cqr->stopclk = get_tod_clock();
2115 			cqr->status = DASD_CQR_CLEARED;
2116 			break;
2117 		default: /* no need to modify the others */
2118 			break;
2119 		}
2120 		list_move_tail(&cqr->devlist, &flush_queue);
2121 	}
2122 finished:
2123 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2124 	/*
2125 	 * After this point all requests must be in state CLEAR_PENDING,
2126 	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2127 	 * one of the others.
2128 	 */
2129 	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2130 		wait_event(dasd_flush_wq,
2131 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
2132 	/*
2133 	 * Now set each request back to TERMINATED, DONE or NEED_ERP
2134 	 * and call the callback function of flushed requests
2135 	 */
2136 	__dasd_device_process_final_queue(device, &flush_queue);
2137 	return rc;
2138 }
2139 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2140 
2141 /*
2142  * Acquire the device lock and process queues for the device.
2143  */
2144 static void dasd_device_tasklet(unsigned long data)
2145 {
2146 	struct dasd_device *device = (struct dasd_device *) data;
2147 	struct list_head final_queue;
2148 
2149 	atomic_set (&device->tasklet_scheduled, 0);
2150 	INIT_LIST_HEAD(&final_queue);
2151 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2152 	/* Check expire time of first request on the ccw queue. */
2153 	__dasd_device_check_expire(device);
2154 	/* find final requests on ccw queue */
2155 	__dasd_device_process_ccw_queue(device, &final_queue);
2156 	__dasd_device_check_path_events(device);
2157 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2158 	/* Now call the callback function of requests with final status */
2159 	__dasd_device_process_final_queue(device, &final_queue);
2160 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2161 	/* Now check if the head of the ccw queue needs to be started. */
2162 	__dasd_device_start_head(device);
2163 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2164 	if (waitqueue_active(&shutdown_waitq))
2165 		wake_up(&shutdown_waitq);
2166 	dasd_put_device(device);
2167 }
2168 
2169 /*
2170  * Schedules a call to dasd_tasklet over the device tasklet.
2171  */
2172 void dasd_schedule_device_bh(struct dasd_device *device)
2173 {
2174 	/* Protect against rescheduling. */
2175 	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2176 		return;
2177 	dasd_get_device(device);
2178 	tasklet_hi_schedule(&device->tasklet);
2179 }
2180 EXPORT_SYMBOL(dasd_schedule_device_bh);
2181 
2182 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2183 {
2184 	device->stopped |= bits;
2185 }
2186 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2187 
2188 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2189 {
2190 	device->stopped &= ~bits;
2191 	if (!device->stopped)
2192 		wake_up(&generic_waitq);
2193 }
2194 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2195 
2196 /*
2197  * Queue a request to the head of the device ccw_queue.
2198  * Start the I/O if possible.
2199  */
2200 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2201 {
2202 	struct dasd_device *device;
2203 	unsigned long flags;
2204 
2205 	device = cqr->startdev;
2206 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2207 	cqr->status = DASD_CQR_QUEUED;
2208 	list_add(&cqr->devlist, &device->ccw_queue);
2209 	/* let the bh start the request to keep them in order */
2210 	dasd_schedule_device_bh(device);
2211 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2212 }
2213 EXPORT_SYMBOL(dasd_add_request_head);
2214 
2215 /*
2216  * Queue a request to the tail of the device ccw_queue.
2217  * Start the I/O if possible.
2218  */
2219 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2220 {
2221 	struct dasd_device *device;
2222 	unsigned long flags;
2223 
2224 	device = cqr->startdev;
2225 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2226 	cqr->status = DASD_CQR_QUEUED;
2227 	list_add_tail(&cqr->devlist, &device->ccw_queue);
2228 	/* let the bh start the request to keep them in order */
2229 	dasd_schedule_device_bh(device);
2230 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2231 }
2232 EXPORT_SYMBOL(dasd_add_request_tail);
2233 
2234 /*
2235  * Wakeup helper for the 'sleep_on' functions.
2236  */
2237 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2238 {
2239 	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2240 	cqr->callback_data = DASD_SLEEPON_END_TAG;
2241 	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2242 	wake_up(&generic_waitq);
2243 }
2244 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2245 
2246 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2247 {
2248 	struct dasd_device *device;
2249 	int rc;
2250 
2251 	device = cqr->startdev;
2252 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2253 	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2254 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2255 	return rc;
2256 }
2257 
2258 /*
2259  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2260  */
2261 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2262 {
2263 	struct dasd_device *device;
2264 	dasd_erp_fn_t erp_fn;
2265 
2266 	if (cqr->status == DASD_CQR_FILLED)
2267 		return 0;
2268 	device = cqr->startdev;
2269 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2270 		if (cqr->status == DASD_CQR_TERMINATED) {
2271 			device->discipline->handle_terminated_request(cqr);
2272 			return 1;
2273 		}
2274 		if (cqr->status == DASD_CQR_NEED_ERP) {
2275 			erp_fn = device->discipline->erp_action(cqr);
2276 			erp_fn(cqr);
2277 			return 1;
2278 		}
2279 		if (cqr->status == DASD_CQR_FAILED)
2280 			dasd_log_sense(cqr, &cqr->irb);
2281 		if (cqr->refers) {
2282 			__dasd_process_erp(device, cqr);
2283 			return 1;
2284 		}
2285 	}
2286 	return 0;
2287 }
2288 
2289 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2290 {
2291 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2292 		if (cqr->refers) /* erp is not done yet */
2293 			return 1;
2294 		return ((cqr->status != DASD_CQR_DONE) &&
2295 			(cqr->status != DASD_CQR_FAILED));
2296 	} else
2297 		return (cqr->status == DASD_CQR_FILLED);
2298 }
2299 
2300 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2301 {
2302 	struct dasd_device *device;
2303 	int rc;
2304 	struct list_head ccw_queue;
2305 	struct dasd_ccw_req *cqr;
2306 
2307 	INIT_LIST_HEAD(&ccw_queue);
2308 	maincqr->status = DASD_CQR_FILLED;
2309 	device = maincqr->startdev;
2310 	list_add(&maincqr->blocklist, &ccw_queue);
2311 	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2312 	     cqr = list_first_entry(&ccw_queue,
2313 				    struct dasd_ccw_req, blocklist)) {
2314 
2315 		if (__dasd_sleep_on_erp(cqr))
2316 			continue;
2317 		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2318 			continue;
2319 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2320 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2321 			cqr->status = DASD_CQR_FAILED;
2322 			cqr->intrc = -EPERM;
2323 			continue;
2324 		}
2325 		/* Non-temporary stop condition will trigger fail fast */
2326 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2327 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2328 		    (!dasd_eer_enabled(device))) {
2329 			cqr->status = DASD_CQR_FAILED;
2330 			cqr->intrc = -ENOLINK;
2331 			continue;
2332 		}
2333 		/*
2334 		 * Don't try to start requests if device is in
2335 		 * offline processing, it might wait forever
2336 		 */
2337 		if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2338 			cqr->status = DASD_CQR_FAILED;
2339 			cqr->intrc = -ENODEV;
2340 			continue;
2341 		}
2342 		/*
2343 		 * Don't try to start requests if device is stopped
2344 		 * except path verification requests
2345 		 */
2346 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2347 			if (interruptible) {
2348 				rc = wait_event_interruptible(
2349 					generic_waitq, !(device->stopped));
2350 				if (rc == -ERESTARTSYS) {
2351 					cqr->status = DASD_CQR_FAILED;
2352 					maincqr->intrc = rc;
2353 					continue;
2354 				}
2355 			} else
2356 				wait_event(generic_waitq, !(device->stopped));
2357 		}
2358 		if (!cqr->callback)
2359 			cqr->callback = dasd_wakeup_cb;
2360 
2361 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2362 		dasd_add_request_tail(cqr);
2363 		if (interruptible) {
2364 			rc = wait_event_interruptible(
2365 				generic_waitq, _wait_for_wakeup(cqr));
2366 			if (rc == -ERESTARTSYS) {
2367 				dasd_cancel_req(cqr);
2368 				/* wait (non-interruptible) for final status */
2369 				wait_event(generic_waitq,
2370 					   _wait_for_wakeup(cqr));
2371 				cqr->status = DASD_CQR_FAILED;
2372 				maincqr->intrc = rc;
2373 				continue;
2374 			}
2375 		} else
2376 			wait_event(generic_waitq, _wait_for_wakeup(cqr));
2377 	}
2378 
2379 	maincqr->endclk = get_tod_clock();
2380 	if ((maincqr->status != DASD_CQR_DONE) &&
2381 	    (maincqr->intrc != -ERESTARTSYS))
2382 		dasd_log_sense(maincqr, &maincqr->irb);
2383 	if (maincqr->status == DASD_CQR_DONE)
2384 		rc = 0;
2385 	else if (maincqr->intrc)
2386 		rc = maincqr->intrc;
2387 	else
2388 		rc = -EIO;
2389 	return rc;
2390 }
2391 
2392 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2393 {
2394 	struct dasd_ccw_req *cqr;
2395 
2396 	list_for_each_entry(cqr, ccw_queue, blocklist) {
2397 		if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2398 			return 0;
2399 	}
2400 
2401 	return 1;
2402 }
2403 
2404 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2405 {
2406 	struct dasd_device *device;
2407 	struct dasd_ccw_req *cqr, *n;
2408 	u8 *sense = NULL;
2409 	int rc;
2410 
2411 retry:
2412 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2413 		device = cqr->startdev;
2414 		if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2415 			continue;
2416 
2417 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2418 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2419 			cqr->status = DASD_CQR_FAILED;
2420 			cqr->intrc = -EPERM;
2421 			continue;
2422 		}
2423 		/*Non-temporary stop condition will trigger fail fast*/
2424 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2425 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2426 		    !dasd_eer_enabled(device)) {
2427 			cqr->status = DASD_CQR_FAILED;
2428 			cqr->intrc = -EAGAIN;
2429 			continue;
2430 		}
2431 
2432 		/*Don't try to start requests if device is stopped*/
2433 		if (interruptible) {
2434 			rc = wait_event_interruptible(
2435 				generic_waitq, !device->stopped);
2436 			if (rc == -ERESTARTSYS) {
2437 				cqr->status = DASD_CQR_FAILED;
2438 				cqr->intrc = rc;
2439 				continue;
2440 			}
2441 		} else
2442 			wait_event(generic_waitq, !(device->stopped));
2443 
2444 		if (!cqr->callback)
2445 			cqr->callback = dasd_wakeup_cb;
2446 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2447 		dasd_add_request_tail(cqr);
2448 	}
2449 
2450 	wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2451 
2452 	rc = 0;
2453 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2454 		/*
2455 		 * In some cases the 'File Protected' or 'Incorrect Length'
2456 		 * error might be expected and error recovery would be
2457 		 * unnecessary in these cases.	Check if the according suppress
2458 		 * bit is set.
2459 		 */
2460 		sense = dasd_get_sense(&cqr->irb);
2461 		if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2462 		    test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2463 			continue;
2464 		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2465 		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2466 			continue;
2467 
2468 		/*
2469 		 * for alias devices simplify error recovery and
2470 		 * return to upper layer
2471 		 * do not skip ERP requests
2472 		 */
2473 		if (cqr->startdev != cqr->basedev && !cqr->refers &&
2474 		    (cqr->status == DASD_CQR_TERMINATED ||
2475 		     cqr->status == DASD_CQR_NEED_ERP))
2476 			return -EAGAIN;
2477 
2478 		/* normal recovery for basedev IO */
2479 		if (__dasd_sleep_on_erp(cqr))
2480 			/* handle erp first */
2481 			goto retry;
2482 	}
2483 
2484 	return 0;
2485 }
2486 
2487 /*
2488  * Queue a request to the tail of the device ccw_queue and wait for
2489  * it's completion.
2490  */
2491 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2492 {
2493 	return _dasd_sleep_on(cqr, 0);
2494 }
2495 EXPORT_SYMBOL(dasd_sleep_on);
2496 
2497 /*
2498  * Start requests from a ccw_queue and wait for their completion.
2499  */
2500 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2501 {
2502 	return _dasd_sleep_on_queue(ccw_queue, 0);
2503 }
2504 EXPORT_SYMBOL(dasd_sleep_on_queue);
2505 
2506 /*
2507  * Start requests from a ccw_queue and wait interruptible for their completion.
2508  */
2509 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2510 {
2511 	return _dasd_sleep_on_queue(ccw_queue, 1);
2512 }
2513 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2514 
2515 /*
2516  * Queue a request to the tail of the device ccw_queue and wait
2517  * interruptible for it's completion.
2518  */
2519 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2520 {
2521 	return _dasd_sleep_on(cqr, 1);
2522 }
2523 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2524 
2525 /*
2526  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2527  * for eckd devices) the currently running request has to be terminated
2528  * and be put back to status queued, before the special request is added
2529  * to the head of the queue. Then the special request is waited on normally.
2530  */
2531 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2532 {
2533 	struct dasd_ccw_req *cqr;
2534 	int rc;
2535 
2536 	if (list_empty(&device->ccw_queue))
2537 		return 0;
2538 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2539 	rc = device->discipline->term_IO(cqr);
2540 	if (!rc)
2541 		/*
2542 		 * CQR terminated because a more important request is pending.
2543 		 * Undo decreasing of retry counter because this is
2544 		 * not an error case.
2545 		 */
2546 		cqr->retries++;
2547 	return rc;
2548 }
2549 
2550 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2551 {
2552 	struct dasd_device *device;
2553 	int rc;
2554 
2555 	device = cqr->startdev;
2556 	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2557 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2558 		cqr->status = DASD_CQR_FAILED;
2559 		cqr->intrc = -EPERM;
2560 		return -EIO;
2561 	}
2562 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2563 	rc = _dasd_term_running_cqr(device);
2564 	if (rc) {
2565 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
2566 		return rc;
2567 	}
2568 	cqr->callback = dasd_wakeup_cb;
2569 	cqr->callback_data = DASD_SLEEPON_START_TAG;
2570 	cqr->status = DASD_CQR_QUEUED;
2571 	/*
2572 	 * add new request as second
2573 	 * first the terminated cqr needs to be finished
2574 	 */
2575 	list_add(&cqr->devlist, device->ccw_queue.next);
2576 
2577 	/* let the bh start the request to keep them in order */
2578 	dasd_schedule_device_bh(device);
2579 
2580 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2581 
2582 	wait_event(generic_waitq, _wait_for_wakeup(cqr));
2583 
2584 	if (cqr->status == DASD_CQR_DONE)
2585 		rc = 0;
2586 	else if (cqr->intrc)
2587 		rc = cqr->intrc;
2588 	else
2589 		rc = -EIO;
2590 
2591 	/* kick tasklets */
2592 	dasd_schedule_device_bh(device);
2593 	if (device->block)
2594 		dasd_schedule_block_bh(device->block);
2595 
2596 	return rc;
2597 }
2598 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2599 
2600 /*
2601  * Cancels a request that was started with dasd_sleep_on_req.
2602  * This is useful to timeout requests. The request will be
2603  * terminated if it is currently in i/o.
2604  * Returns 0 if request termination was successful
2605  *	   negative error code if termination failed
2606  * Cancellation of a request is an asynchronous operation! The calling
2607  * function has to wait until the request is properly returned via callback.
2608  */
2609 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2610 {
2611 	struct dasd_device *device = cqr->startdev;
2612 	int rc = 0;
2613 
2614 	switch (cqr->status) {
2615 	case DASD_CQR_QUEUED:
2616 		/* request was not started - just set to cleared */
2617 		cqr->status = DASD_CQR_CLEARED;
2618 		break;
2619 	case DASD_CQR_IN_IO:
2620 		/* request in IO - terminate IO and release again */
2621 		rc = device->discipline->term_IO(cqr);
2622 		if (rc) {
2623 			dev_err(&device->cdev->dev,
2624 				"Cancelling request %p failed with rc=%d\n",
2625 				cqr, rc);
2626 		} else {
2627 			cqr->stopclk = get_tod_clock();
2628 		}
2629 		break;
2630 	default: /* already finished or clear pending - do nothing */
2631 		break;
2632 	}
2633 	dasd_schedule_device_bh(device);
2634 	return rc;
2635 }
2636 
2637 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2638 {
2639 	struct dasd_device *device = cqr->startdev;
2640 	unsigned long flags;
2641 	int rc;
2642 
2643 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2644 	rc = __dasd_cancel_req(cqr);
2645 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2646 	return rc;
2647 }
2648 
2649 /*
2650  * SECTION: Operations of the dasd_block layer.
2651  */
2652 
2653 /*
2654  * Timeout function for dasd_block. This is used when the block layer
2655  * is waiting for something that may not come reliably, (e.g. a state
2656  * change interrupt)
2657  */
2658 static void dasd_block_timeout(struct timer_list *t)
2659 {
2660 	unsigned long flags;
2661 	struct dasd_block *block;
2662 
2663 	block = from_timer(block, t, timer);
2664 	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2665 	/* re-activate request queue */
2666 	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2667 	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2668 	dasd_schedule_block_bh(block);
2669 	blk_mq_run_hw_queues(block->gdp->queue, true);
2670 }
2671 
2672 /*
2673  * Setup timeout for a dasd_block in jiffies.
2674  */
2675 void dasd_block_set_timer(struct dasd_block *block, int expires)
2676 {
2677 	if (expires == 0)
2678 		del_timer(&block->timer);
2679 	else
2680 		mod_timer(&block->timer, jiffies + expires);
2681 }
2682 EXPORT_SYMBOL(dasd_block_set_timer);
2683 
2684 /*
2685  * Clear timeout for a dasd_block.
2686  */
2687 void dasd_block_clear_timer(struct dasd_block *block)
2688 {
2689 	del_timer(&block->timer);
2690 }
2691 EXPORT_SYMBOL(dasd_block_clear_timer);
2692 
2693 /*
2694  * Process finished error recovery ccw.
2695  */
2696 static void __dasd_process_erp(struct dasd_device *device,
2697 			       struct dasd_ccw_req *cqr)
2698 {
2699 	dasd_erp_fn_t erp_fn;
2700 
2701 	if (cqr->status == DASD_CQR_DONE)
2702 		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2703 	else
2704 		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2705 	erp_fn = device->discipline->erp_postaction(cqr);
2706 	erp_fn(cqr);
2707 }
2708 
2709 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2710 {
2711 	struct request *req;
2712 	blk_status_t error = BLK_STS_OK;
2713 	unsigned int proc_bytes;
2714 	int status;
2715 
2716 	req = (struct request *) cqr->callback_data;
2717 	dasd_profile_end(cqr->block, cqr, req);
2718 
2719 	proc_bytes = cqr->proc_bytes;
2720 	status = cqr->block->base->discipline->free_cp(cqr, req);
2721 	if (status < 0)
2722 		error = errno_to_blk_status(status);
2723 	else if (status == 0) {
2724 		switch (cqr->intrc) {
2725 		case -EPERM:
2726 			error = BLK_STS_NEXUS;
2727 			break;
2728 		case -ENOLINK:
2729 			error = BLK_STS_TRANSPORT;
2730 			break;
2731 		case -ETIMEDOUT:
2732 			error = BLK_STS_TIMEOUT;
2733 			break;
2734 		default:
2735 			error = BLK_STS_IOERR;
2736 			break;
2737 		}
2738 	}
2739 
2740 	/*
2741 	 * We need to take care for ETIMEDOUT errors here since the
2742 	 * complete callback does not get called in this case.
2743 	 * Take care of all errors here and avoid additional code to
2744 	 * transfer the error value to the complete callback.
2745 	 */
2746 	if (error) {
2747 		blk_mq_end_request(req, error);
2748 		blk_mq_run_hw_queues(req->q, true);
2749 	} else {
2750 		/*
2751 		 * Partial completed requests can happen with ESE devices.
2752 		 * During read we might have gotten a NRF error and have to
2753 		 * complete a request partially.
2754 		 */
2755 		if (proc_bytes) {
2756 			blk_update_request(req, BLK_STS_OK, proc_bytes);
2757 			blk_mq_requeue_request(req, true);
2758 		} else if (likely(!blk_should_fake_timeout(req->q))) {
2759 			blk_mq_complete_request(req);
2760 		}
2761 	}
2762 }
2763 
2764 /*
2765  * Process ccw request queue.
2766  */
2767 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2768 					   struct list_head *final_queue)
2769 {
2770 	struct list_head *l, *n;
2771 	struct dasd_ccw_req *cqr;
2772 	dasd_erp_fn_t erp_fn;
2773 	unsigned long flags;
2774 	struct dasd_device *base = block->base;
2775 
2776 restart:
2777 	/* Process request with final status. */
2778 	list_for_each_safe(l, n, &block->ccw_queue) {
2779 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2780 		if (cqr->status != DASD_CQR_DONE &&
2781 		    cqr->status != DASD_CQR_FAILED &&
2782 		    cqr->status != DASD_CQR_NEED_ERP &&
2783 		    cqr->status != DASD_CQR_TERMINATED)
2784 			continue;
2785 
2786 		if (cqr->status == DASD_CQR_TERMINATED) {
2787 			base->discipline->handle_terminated_request(cqr);
2788 			goto restart;
2789 		}
2790 
2791 		/*  Process requests that may be recovered */
2792 		if (cqr->status == DASD_CQR_NEED_ERP) {
2793 			erp_fn = base->discipline->erp_action(cqr);
2794 			if (IS_ERR(erp_fn(cqr)))
2795 				continue;
2796 			goto restart;
2797 		}
2798 
2799 		/* log sense for fatal error */
2800 		if (cqr->status == DASD_CQR_FAILED) {
2801 			dasd_log_sense(cqr, &cqr->irb);
2802 		}
2803 
2804 		/* First of all call extended error reporting. */
2805 		if (dasd_eer_enabled(base) &&
2806 		    cqr->status == DASD_CQR_FAILED) {
2807 			dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2808 
2809 			/* restart request  */
2810 			cqr->status = DASD_CQR_FILLED;
2811 			cqr->retries = 255;
2812 			spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2813 			dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2814 			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2815 					       flags);
2816 			goto restart;
2817 		}
2818 
2819 		/* Process finished ERP request. */
2820 		if (cqr->refers) {
2821 			__dasd_process_erp(base, cqr);
2822 			goto restart;
2823 		}
2824 
2825 		/* Rechain finished requests to final queue */
2826 		cqr->endclk = get_tod_clock();
2827 		list_move_tail(&cqr->blocklist, final_queue);
2828 	}
2829 }
2830 
2831 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2832 {
2833 	dasd_schedule_block_bh(cqr->block);
2834 }
2835 
2836 static void __dasd_block_start_head(struct dasd_block *block)
2837 {
2838 	struct dasd_ccw_req *cqr;
2839 
2840 	if (list_empty(&block->ccw_queue))
2841 		return;
2842 	/* We allways begin with the first requests on the queue, as some
2843 	 * of previously started requests have to be enqueued on a
2844 	 * dasd_device again for error recovery.
2845 	 */
2846 	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2847 		if (cqr->status != DASD_CQR_FILLED)
2848 			continue;
2849 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2850 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2851 			cqr->status = DASD_CQR_FAILED;
2852 			cqr->intrc = -EPERM;
2853 			dasd_schedule_block_bh(block);
2854 			continue;
2855 		}
2856 		/* Non-temporary stop condition will trigger fail fast */
2857 		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2858 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2859 		    (!dasd_eer_enabled(block->base))) {
2860 			cqr->status = DASD_CQR_FAILED;
2861 			cqr->intrc = -ENOLINK;
2862 			dasd_schedule_block_bh(block);
2863 			continue;
2864 		}
2865 		/* Don't try to start requests if device is stopped */
2866 		if (block->base->stopped)
2867 			return;
2868 
2869 		/* just a fail safe check, should not happen */
2870 		if (!cqr->startdev)
2871 			cqr->startdev = block->base;
2872 
2873 		/* make sure that the requests we submit find their way back */
2874 		cqr->callback = dasd_return_cqr_cb;
2875 
2876 		dasd_add_request_tail(cqr);
2877 	}
2878 }
2879 
2880 /*
2881  * Central dasd_block layer routine. Takes requests from the generic
2882  * block layer request queue, creates ccw requests, enqueues them on
2883  * a dasd_device and processes ccw requests that have been returned.
2884  */
2885 static void dasd_block_tasklet(unsigned long data)
2886 {
2887 	struct dasd_block *block = (struct dasd_block *) data;
2888 	struct list_head final_queue;
2889 	struct list_head *l, *n;
2890 	struct dasd_ccw_req *cqr;
2891 	struct dasd_queue *dq;
2892 
2893 	atomic_set(&block->tasklet_scheduled, 0);
2894 	INIT_LIST_HEAD(&final_queue);
2895 	spin_lock_irq(&block->queue_lock);
2896 	/* Finish off requests on ccw queue */
2897 	__dasd_process_block_ccw_queue(block, &final_queue);
2898 	spin_unlock_irq(&block->queue_lock);
2899 
2900 	/* Now call the callback function of requests with final status */
2901 	list_for_each_safe(l, n, &final_queue) {
2902 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2903 		dq = cqr->dq;
2904 		spin_lock_irq(&dq->lock);
2905 		list_del_init(&cqr->blocklist);
2906 		__dasd_cleanup_cqr(cqr);
2907 		spin_unlock_irq(&dq->lock);
2908 	}
2909 
2910 	spin_lock_irq(&block->queue_lock);
2911 	/* Now check if the head of the ccw queue needs to be started. */
2912 	__dasd_block_start_head(block);
2913 	spin_unlock_irq(&block->queue_lock);
2914 
2915 	if (waitqueue_active(&shutdown_waitq))
2916 		wake_up(&shutdown_waitq);
2917 	dasd_put_device(block->base);
2918 }
2919 
2920 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2921 {
2922 	wake_up(&dasd_flush_wq);
2923 }
2924 
2925 /*
2926  * Requeue a request back to the block request queue
2927  * only works for block requests
2928  */
2929 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2930 {
2931 	struct dasd_block *block = cqr->block;
2932 	struct request *req;
2933 
2934 	if (!block)
2935 		return -EINVAL;
2936 	/*
2937 	 * If the request is an ERP request there is nothing to requeue.
2938 	 * This will be done with the remaining original request.
2939 	 */
2940 	if (cqr->refers)
2941 		return 0;
2942 	spin_lock_irq(&cqr->dq->lock);
2943 	req = (struct request *) cqr->callback_data;
2944 	blk_mq_requeue_request(req, false);
2945 	spin_unlock_irq(&cqr->dq->lock);
2946 
2947 	return 0;
2948 }
2949 
2950 /*
2951  * Go through all request on the dasd_block request queue, cancel them
2952  * on the respective dasd_device, and return them to the generic
2953  * block layer.
2954  */
2955 static int dasd_flush_block_queue(struct dasd_block *block)
2956 {
2957 	struct dasd_ccw_req *cqr, *n;
2958 	int rc, i;
2959 	struct list_head flush_queue;
2960 	unsigned long flags;
2961 
2962 	INIT_LIST_HEAD(&flush_queue);
2963 	spin_lock_bh(&block->queue_lock);
2964 	rc = 0;
2965 restart:
2966 	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2967 		/* if this request currently owned by a dasd_device cancel it */
2968 		if (cqr->status >= DASD_CQR_QUEUED)
2969 			rc = dasd_cancel_req(cqr);
2970 		if (rc < 0)
2971 			break;
2972 		/* Rechain request (including erp chain) so it won't be
2973 		 * touched by the dasd_block_tasklet anymore.
2974 		 * Replace the callback so we notice when the request
2975 		 * is returned from the dasd_device layer.
2976 		 */
2977 		cqr->callback = _dasd_wake_block_flush_cb;
2978 		for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2979 			list_move_tail(&cqr->blocklist, &flush_queue);
2980 		if (i > 1)
2981 			/* moved more than one request - need to restart */
2982 			goto restart;
2983 	}
2984 	spin_unlock_bh(&block->queue_lock);
2985 	/* Now call the callback function of flushed requests */
2986 restart_cb:
2987 	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2988 		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2989 		/* Process finished ERP request. */
2990 		if (cqr->refers) {
2991 			spin_lock_bh(&block->queue_lock);
2992 			__dasd_process_erp(block->base, cqr);
2993 			spin_unlock_bh(&block->queue_lock);
2994 			/* restart list_for_xx loop since dasd_process_erp
2995 			 * might remove multiple elements */
2996 			goto restart_cb;
2997 		}
2998 		/* call the callback function */
2999 		spin_lock_irqsave(&cqr->dq->lock, flags);
3000 		cqr->endclk = get_tod_clock();
3001 		list_del_init(&cqr->blocklist);
3002 		__dasd_cleanup_cqr(cqr);
3003 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3004 	}
3005 	return rc;
3006 }
3007 
3008 /*
3009  * Schedules a call to dasd_tasklet over the device tasklet.
3010  */
3011 void dasd_schedule_block_bh(struct dasd_block *block)
3012 {
3013 	/* Protect against rescheduling. */
3014 	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3015 		return;
3016 	/* life cycle of block is bound to it's base device */
3017 	dasd_get_device(block->base);
3018 	tasklet_hi_schedule(&block->tasklet);
3019 }
3020 EXPORT_SYMBOL(dasd_schedule_block_bh);
3021 
3022 
3023 /*
3024  * SECTION: external block device operations
3025  * (request queue handling, open, release, etc.)
3026  */
3027 
3028 /*
3029  * Dasd request queue function. Called from ll_rw_blk.c
3030  */
3031 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3032 				    const struct blk_mq_queue_data *qd)
3033 {
3034 	struct dasd_block *block = hctx->queue->queuedata;
3035 	struct dasd_queue *dq = hctx->driver_data;
3036 	struct request *req = qd->rq;
3037 	struct dasd_device *basedev;
3038 	struct dasd_ccw_req *cqr;
3039 	blk_status_t rc = BLK_STS_OK;
3040 
3041 	basedev = block->base;
3042 	spin_lock_irq(&dq->lock);
3043 	if (basedev->state < DASD_STATE_READY ||
3044 	    test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
3045 		DBF_DEV_EVENT(DBF_ERR, basedev,
3046 			      "device not ready for request %p", req);
3047 		rc = BLK_STS_IOERR;
3048 		goto out;
3049 	}
3050 
3051 	/*
3052 	 * if device is stopped do not fetch new requests
3053 	 * except failfast is active which will let requests fail
3054 	 * immediately in __dasd_block_start_head()
3055 	 */
3056 	if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3057 		DBF_DEV_EVENT(DBF_ERR, basedev,
3058 			      "device stopped request %p", req);
3059 		rc = BLK_STS_RESOURCE;
3060 		goto out;
3061 	}
3062 
3063 	if (basedev->features & DASD_FEATURE_READONLY &&
3064 	    rq_data_dir(req) == WRITE) {
3065 		DBF_DEV_EVENT(DBF_ERR, basedev,
3066 			      "Rejecting write request %p", req);
3067 		rc = BLK_STS_IOERR;
3068 		goto out;
3069 	}
3070 
3071 	if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3072 	    (basedev->features & DASD_FEATURE_FAILFAST ||
3073 	     blk_noretry_request(req))) {
3074 		DBF_DEV_EVENT(DBF_ERR, basedev,
3075 			      "Rejecting failfast request %p", req);
3076 		rc = BLK_STS_IOERR;
3077 		goto out;
3078 	}
3079 
3080 	cqr = basedev->discipline->build_cp(basedev, block, req);
3081 	if (IS_ERR(cqr)) {
3082 		if (PTR_ERR(cqr) == -EBUSY ||
3083 		    PTR_ERR(cqr) == -ENOMEM ||
3084 		    PTR_ERR(cqr) == -EAGAIN) {
3085 			rc = BLK_STS_RESOURCE;
3086 			goto out;
3087 		}
3088 		DBF_DEV_EVENT(DBF_ERR, basedev,
3089 			      "CCW creation failed (rc=%ld) on request %p",
3090 			      PTR_ERR(cqr), req);
3091 		rc = BLK_STS_IOERR;
3092 		goto out;
3093 	}
3094 	/*
3095 	 *  Note: callback is set to dasd_return_cqr_cb in
3096 	 * __dasd_block_start_head to cover erp requests as well
3097 	 */
3098 	cqr->callback_data = req;
3099 	cqr->status = DASD_CQR_FILLED;
3100 	cqr->dq = dq;
3101 
3102 	blk_mq_start_request(req);
3103 	spin_lock(&block->queue_lock);
3104 	list_add_tail(&cqr->blocklist, &block->ccw_queue);
3105 	INIT_LIST_HEAD(&cqr->devlist);
3106 	dasd_profile_start(block, cqr, req);
3107 	dasd_schedule_block_bh(block);
3108 	spin_unlock(&block->queue_lock);
3109 
3110 out:
3111 	spin_unlock_irq(&dq->lock);
3112 	return rc;
3113 }
3114 
3115 /*
3116  * Block timeout callback, called from the block layer
3117  *
3118  * Return values:
3119  * BLK_EH_RESET_TIMER if the request should be left running
3120  * BLK_EH_DONE if the request is handled or terminated
3121  *		      by the driver.
3122  */
3123 enum blk_eh_timer_return dasd_times_out(struct request *req)
3124 {
3125 	struct dasd_block *block = req->q->queuedata;
3126 	struct dasd_device *device;
3127 	struct dasd_ccw_req *cqr;
3128 	unsigned long flags;
3129 	int rc = 0;
3130 
3131 	cqr = blk_mq_rq_to_pdu(req);
3132 	if (!cqr)
3133 		return BLK_EH_DONE;
3134 
3135 	spin_lock_irqsave(&cqr->dq->lock, flags);
3136 	device = cqr->startdev ? cqr->startdev : block->base;
3137 	if (!device->blk_timeout) {
3138 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3139 		return BLK_EH_RESET_TIMER;
3140 	}
3141 	DBF_DEV_EVENT(DBF_WARNING, device,
3142 		      " dasd_times_out cqr %p status %x",
3143 		      cqr, cqr->status);
3144 
3145 	spin_lock(&block->queue_lock);
3146 	spin_lock(get_ccwdev_lock(device->cdev));
3147 	cqr->retries = -1;
3148 	cqr->intrc = -ETIMEDOUT;
3149 	if (cqr->status >= DASD_CQR_QUEUED) {
3150 		rc = __dasd_cancel_req(cqr);
3151 	} else if (cqr->status == DASD_CQR_FILLED ||
3152 		   cqr->status == DASD_CQR_NEED_ERP) {
3153 		cqr->status = DASD_CQR_TERMINATED;
3154 	} else if (cqr->status == DASD_CQR_IN_ERP) {
3155 		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3156 
3157 		list_for_each_entry_safe(searchcqr, nextcqr,
3158 					 &block->ccw_queue, blocklist) {
3159 			tmpcqr = searchcqr;
3160 			while (tmpcqr->refers)
3161 				tmpcqr = tmpcqr->refers;
3162 			if (tmpcqr != cqr)
3163 				continue;
3164 			/* searchcqr is an ERP request for cqr */
3165 			searchcqr->retries = -1;
3166 			searchcqr->intrc = -ETIMEDOUT;
3167 			if (searchcqr->status >= DASD_CQR_QUEUED) {
3168 				rc = __dasd_cancel_req(searchcqr);
3169 			} else if ((searchcqr->status == DASD_CQR_FILLED) ||
3170 				   (searchcqr->status == DASD_CQR_NEED_ERP)) {
3171 				searchcqr->status = DASD_CQR_TERMINATED;
3172 				rc = 0;
3173 			} else if (searchcqr->status == DASD_CQR_IN_ERP) {
3174 				/*
3175 				 * Shouldn't happen; most recent ERP
3176 				 * request is at the front of queue
3177 				 */
3178 				continue;
3179 			}
3180 			break;
3181 		}
3182 	}
3183 	spin_unlock(get_ccwdev_lock(device->cdev));
3184 	dasd_schedule_block_bh(block);
3185 	spin_unlock(&block->queue_lock);
3186 	spin_unlock_irqrestore(&cqr->dq->lock, flags);
3187 
3188 	return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3189 }
3190 
3191 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3192 			  unsigned int idx)
3193 {
3194 	struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3195 
3196 	if (!dq)
3197 		return -ENOMEM;
3198 
3199 	spin_lock_init(&dq->lock);
3200 	hctx->driver_data = dq;
3201 
3202 	return 0;
3203 }
3204 
3205 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3206 {
3207 	kfree(hctx->driver_data);
3208 	hctx->driver_data = NULL;
3209 }
3210 
3211 static void dasd_request_done(struct request *req)
3212 {
3213 	blk_mq_end_request(req, 0);
3214 	blk_mq_run_hw_queues(req->q, true);
3215 }
3216 
3217 struct blk_mq_ops dasd_mq_ops = {
3218 	.queue_rq = do_dasd_request,
3219 	.complete = dasd_request_done,
3220 	.timeout = dasd_times_out,
3221 	.init_hctx = dasd_init_hctx,
3222 	.exit_hctx = dasd_exit_hctx,
3223 };
3224 
3225 static int dasd_open(struct block_device *bdev, fmode_t mode)
3226 {
3227 	struct dasd_device *base;
3228 	int rc;
3229 
3230 	base = dasd_device_from_gendisk(bdev->bd_disk);
3231 	if (!base)
3232 		return -ENODEV;
3233 
3234 	atomic_inc(&base->block->open_count);
3235 	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3236 		rc = -ENODEV;
3237 		goto unlock;
3238 	}
3239 
3240 	if (!try_module_get(base->discipline->owner)) {
3241 		rc = -EINVAL;
3242 		goto unlock;
3243 	}
3244 
3245 	if (dasd_probeonly) {
3246 		dev_info(&base->cdev->dev,
3247 			 "Accessing the DASD failed because it is in "
3248 			 "probeonly mode\n");
3249 		rc = -EPERM;
3250 		goto out;
3251 	}
3252 
3253 	if (base->state <= DASD_STATE_BASIC) {
3254 		DBF_DEV_EVENT(DBF_ERR, base, " %s",
3255 			      " Cannot open unrecognized device");
3256 		rc = -ENODEV;
3257 		goto out;
3258 	}
3259 
3260 	if ((mode & FMODE_WRITE) &&
3261 	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3262 	     (base->features & DASD_FEATURE_READONLY))) {
3263 		rc = -EROFS;
3264 		goto out;
3265 	}
3266 
3267 	dasd_put_device(base);
3268 	return 0;
3269 
3270 out:
3271 	module_put(base->discipline->owner);
3272 unlock:
3273 	atomic_dec(&base->block->open_count);
3274 	dasd_put_device(base);
3275 	return rc;
3276 }
3277 
3278 static void dasd_release(struct gendisk *disk, fmode_t mode)
3279 {
3280 	struct dasd_device *base = dasd_device_from_gendisk(disk);
3281 	if (base) {
3282 		atomic_dec(&base->block->open_count);
3283 		module_put(base->discipline->owner);
3284 		dasd_put_device(base);
3285 	}
3286 }
3287 
3288 /*
3289  * Return disk geometry.
3290  */
3291 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3292 {
3293 	struct dasd_device *base;
3294 
3295 	base = dasd_device_from_gendisk(bdev->bd_disk);
3296 	if (!base)
3297 		return -ENODEV;
3298 
3299 	if (!base->discipline ||
3300 	    !base->discipline->fill_geometry) {
3301 		dasd_put_device(base);
3302 		return -EINVAL;
3303 	}
3304 	base->discipline->fill_geometry(base->block, geo);
3305 	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3306 	dasd_put_device(base);
3307 	return 0;
3308 }
3309 
3310 const struct block_device_operations
3311 dasd_device_operations = {
3312 	.owner		= THIS_MODULE,
3313 	.open		= dasd_open,
3314 	.release	= dasd_release,
3315 	.ioctl		= dasd_ioctl,
3316 	.compat_ioctl	= dasd_ioctl,
3317 	.getgeo		= dasd_getgeo,
3318 	.set_read_only	= dasd_set_read_only,
3319 };
3320 
3321 /*******************************************************************************
3322  * end of block device operations
3323  */
3324 
3325 static void
3326 dasd_exit(void)
3327 {
3328 #ifdef CONFIG_PROC_FS
3329 	dasd_proc_exit();
3330 #endif
3331 	dasd_eer_exit();
3332 	kmem_cache_destroy(dasd_page_cache);
3333 	dasd_page_cache = NULL;
3334 	dasd_gendisk_exit();
3335 	dasd_devmap_exit();
3336 	if (dasd_debug_area != NULL) {
3337 		debug_unregister(dasd_debug_area);
3338 		dasd_debug_area = NULL;
3339 	}
3340 	dasd_statistics_removeroot();
3341 }
3342 
3343 /*
3344  * SECTION: common functions for ccw_driver use
3345  */
3346 
3347 /*
3348  * Is the device read-only?
3349  * Note that this function does not report the setting of the
3350  * readonly device attribute, but how it is configured in z/VM.
3351  */
3352 int dasd_device_is_ro(struct dasd_device *device)
3353 {
3354 	struct ccw_dev_id dev_id;
3355 	struct diag210 diag_data;
3356 	int rc;
3357 
3358 	if (!MACHINE_IS_VM)
3359 		return 0;
3360 	ccw_device_get_id(device->cdev, &dev_id);
3361 	memset(&diag_data, 0, sizeof(diag_data));
3362 	diag_data.vrdcdvno = dev_id.devno;
3363 	diag_data.vrdclen = sizeof(diag_data);
3364 	rc = diag210(&diag_data);
3365 	if (rc == 0 || rc == 2) {
3366 		return diag_data.vrdcvfla & 0x80;
3367 	} else {
3368 		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3369 			  dev_id.devno, rc);
3370 		return 0;
3371 	}
3372 }
3373 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3374 
3375 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3376 {
3377 	struct ccw_device *cdev = data;
3378 	int ret;
3379 
3380 	ret = ccw_device_set_online(cdev);
3381 	if (ret)
3382 		pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3383 			dev_name(&cdev->dev), ret);
3384 }
3385 
3386 /*
3387  * Initial attempt at a probe function. this can be simplified once
3388  * the other detection code is gone.
3389  */
3390 int dasd_generic_probe(struct ccw_device *cdev)
3391 {
3392 	cdev->handler = &dasd_int_handler;
3393 
3394 	/*
3395 	 * Automatically online either all dasd devices (dasd_autodetect)
3396 	 * or all devices specified with dasd= parameters during
3397 	 * initial probe.
3398 	 */
3399 	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3400 	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3401 		async_schedule(dasd_generic_auto_online, cdev);
3402 	return 0;
3403 }
3404 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3405 
3406 void dasd_generic_free_discipline(struct dasd_device *device)
3407 {
3408 	/* Forget the discipline information. */
3409 	if (device->discipline) {
3410 		if (device->discipline->uncheck_device)
3411 			device->discipline->uncheck_device(device);
3412 		module_put(device->discipline->owner);
3413 		device->discipline = NULL;
3414 	}
3415 	if (device->base_discipline) {
3416 		module_put(device->base_discipline->owner);
3417 		device->base_discipline = NULL;
3418 	}
3419 }
3420 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3421 
3422 /*
3423  * This will one day be called from a global not_oper handler.
3424  * It is also used by driver_unregister during module unload.
3425  */
3426 void dasd_generic_remove(struct ccw_device *cdev)
3427 {
3428 	struct dasd_device *device;
3429 	struct dasd_block *block;
3430 
3431 	device = dasd_device_from_cdev(cdev);
3432 	if (IS_ERR(device))
3433 		return;
3434 
3435 	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3436 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3437 		/* Already doing offline processing */
3438 		dasd_put_device(device);
3439 		return;
3440 	}
3441 	/*
3442 	 * This device is removed unconditionally. Set offline
3443 	 * flag to prevent dasd_open from opening it while it is
3444 	 * no quite down yet.
3445 	 */
3446 	dasd_set_target_state(device, DASD_STATE_NEW);
3447 	cdev->handler = NULL;
3448 	/* dasd_delete_device destroys the device reference. */
3449 	block = device->block;
3450 	dasd_delete_device(device);
3451 	/*
3452 	 * life cycle of block is bound to device, so delete it after
3453 	 * device was safely removed
3454 	 */
3455 	if (block)
3456 		dasd_free_block(block);
3457 }
3458 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3459 
3460 /*
3461  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3462  * the device is detected for the first time and is supposed to be used
3463  * or the user has started activation through sysfs.
3464  */
3465 int dasd_generic_set_online(struct ccw_device *cdev,
3466 			    struct dasd_discipline *base_discipline)
3467 {
3468 	struct dasd_discipline *discipline;
3469 	struct dasd_device *device;
3470 	int rc;
3471 
3472 	/* first online clears initial online feature flag */
3473 	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3474 	device = dasd_create_device(cdev);
3475 	if (IS_ERR(device))
3476 		return PTR_ERR(device);
3477 
3478 	discipline = base_discipline;
3479 	if (device->features & DASD_FEATURE_USEDIAG) {
3480 	  	if (!dasd_diag_discipline_pointer) {
3481 			/* Try to load the required module. */
3482 			rc = request_module(DASD_DIAG_MOD);
3483 			if (rc) {
3484 				pr_warn("%s Setting the DASD online failed "
3485 					"because the required module %s "
3486 					"could not be loaded (rc=%d)\n",
3487 					dev_name(&cdev->dev), DASD_DIAG_MOD,
3488 					rc);
3489 				dasd_delete_device(device);
3490 				return -ENODEV;
3491 			}
3492 		}
3493 		/* Module init could have failed, so check again here after
3494 		 * request_module(). */
3495 		if (!dasd_diag_discipline_pointer) {
3496 			pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3497 				dev_name(&cdev->dev));
3498 			dasd_delete_device(device);
3499 			return -ENODEV;
3500 		}
3501 		discipline = dasd_diag_discipline_pointer;
3502 	}
3503 	if (!try_module_get(base_discipline->owner)) {
3504 		dasd_delete_device(device);
3505 		return -EINVAL;
3506 	}
3507 	if (!try_module_get(discipline->owner)) {
3508 		module_put(base_discipline->owner);
3509 		dasd_delete_device(device);
3510 		return -EINVAL;
3511 	}
3512 	device->base_discipline = base_discipline;
3513 	device->discipline = discipline;
3514 
3515 	/* check_device will allocate block device if necessary */
3516 	rc = discipline->check_device(device);
3517 	if (rc) {
3518 		pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3519 			dev_name(&cdev->dev), discipline->name, rc);
3520 		module_put(discipline->owner);
3521 		module_put(base_discipline->owner);
3522 		dasd_delete_device(device);
3523 		return rc;
3524 	}
3525 
3526 	dasd_set_target_state(device, DASD_STATE_ONLINE);
3527 	if (device->state <= DASD_STATE_KNOWN) {
3528 		pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3529 			dev_name(&cdev->dev));
3530 		rc = -ENODEV;
3531 		dasd_set_target_state(device, DASD_STATE_NEW);
3532 		if (device->block)
3533 			dasd_free_block(device->block);
3534 		dasd_delete_device(device);
3535 	} else
3536 		pr_debug("dasd_generic device %s found\n",
3537 				dev_name(&cdev->dev));
3538 
3539 	wait_event(dasd_init_waitq, _wait_for_device(device));
3540 
3541 	dasd_put_device(device);
3542 	return rc;
3543 }
3544 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3545 
3546 int dasd_generic_set_offline(struct ccw_device *cdev)
3547 {
3548 	struct dasd_device *device;
3549 	struct dasd_block *block;
3550 	int max_count, open_count, rc;
3551 	unsigned long flags;
3552 
3553 	rc = 0;
3554 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3555 	device = dasd_device_from_cdev_locked(cdev);
3556 	if (IS_ERR(device)) {
3557 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3558 		return PTR_ERR(device);
3559 	}
3560 
3561 	/*
3562 	 * We must make sure that this device is currently not in use.
3563 	 * The open_count is increased for every opener, that includes
3564 	 * the blkdev_get in dasd_scan_partitions. We are only interested
3565 	 * in the other openers.
3566 	 */
3567 	if (device->block) {
3568 		max_count = device->block->bdev ? 0 : -1;
3569 		open_count = atomic_read(&device->block->open_count);
3570 		if (open_count > max_count) {
3571 			if (open_count > 0)
3572 				pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3573 					dev_name(&cdev->dev), open_count);
3574 			else
3575 				pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3576 					dev_name(&cdev->dev));
3577 			rc = -EBUSY;
3578 			goto out_err;
3579 		}
3580 	}
3581 
3582 	/*
3583 	 * Test if the offline processing is already running and exit if so.
3584 	 * If a safe offline is being processed this could only be a normal
3585 	 * offline that should be able to overtake the safe offline and
3586 	 * cancel any I/O we do not want to wait for any longer
3587 	 */
3588 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3589 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3590 			clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3591 				  &device->flags);
3592 		} else {
3593 			rc = -EBUSY;
3594 			goto out_err;
3595 		}
3596 	}
3597 	set_bit(DASD_FLAG_OFFLINE, &device->flags);
3598 
3599 	/*
3600 	 * if safe_offline is called set safe_offline_running flag and
3601 	 * clear safe_offline so that a call to normal offline
3602 	 * can overrun safe_offline processing
3603 	 */
3604 	if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3605 	    !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3606 		/* need to unlock here to wait for outstanding I/O */
3607 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3608 		/*
3609 		 * If we want to set the device safe offline all IO operations
3610 		 * should be finished before continuing the offline process
3611 		 * so sync bdev first and then wait for our queues to become
3612 		 * empty
3613 		 */
3614 		if (device->block) {
3615 			rc = fsync_bdev(device->block->bdev);
3616 			if (rc != 0)
3617 				goto interrupted;
3618 		}
3619 		dasd_schedule_device_bh(device);
3620 		rc = wait_event_interruptible(shutdown_waitq,
3621 					      _wait_for_empty_queues(device));
3622 		if (rc != 0)
3623 			goto interrupted;
3624 
3625 		/*
3626 		 * check if a normal offline process overtook the offline
3627 		 * processing in this case simply do nothing beside returning
3628 		 * that we got interrupted
3629 		 * otherwise mark safe offline as not running any longer and
3630 		 * continue with normal offline
3631 		 */
3632 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3633 		if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3634 			rc = -ERESTARTSYS;
3635 			goto out_err;
3636 		}
3637 		clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3638 	}
3639 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3640 
3641 	dasd_set_target_state(device, DASD_STATE_NEW);
3642 	/* dasd_delete_device destroys the device reference. */
3643 	block = device->block;
3644 	dasd_delete_device(device);
3645 	/*
3646 	 * life cycle of block is bound to device, so delete it after
3647 	 * device was safely removed
3648 	 */
3649 	if (block)
3650 		dasd_free_block(block);
3651 
3652 	return 0;
3653 
3654 interrupted:
3655 	/* interrupted by signal */
3656 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3657 	clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3658 	clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3659 out_err:
3660 	dasd_put_device(device);
3661 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3662 	return rc;
3663 }
3664 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3665 
3666 int dasd_generic_last_path_gone(struct dasd_device *device)
3667 {
3668 	struct dasd_ccw_req *cqr;
3669 
3670 	dev_warn(&device->cdev->dev, "No operational channel path is left "
3671 		 "for the device\n");
3672 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3673 	/* First of all call extended error reporting. */
3674 	dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3675 
3676 	if (device->state < DASD_STATE_BASIC)
3677 		return 0;
3678 	/* Device is active. We want to keep it. */
3679 	list_for_each_entry(cqr, &device->ccw_queue, devlist)
3680 		if ((cqr->status == DASD_CQR_IN_IO) ||
3681 		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3682 			cqr->status = DASD_CQR_QUEUED;
3683 			cqr->retries++;
3684 		}
3685 	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3686 	dasd_device_clear_timer(device);
3687 	dasd_schedule_device_bh(device);
3688 	return 1;
3689 }
3690 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3691 
3692 int dasd_generic_path_operational(struct dasd_device *device)
3693 {
3694 	dev_info(&device->cdev->dev, "A channel path to the device has become "
3695 		 "operational\n");
3696 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3697 	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3698 	dasd_schedule_device_bh(device);
3699 	if (device->block) {
3700 		dasd_schedule_block_bh(device->block);
3701 		if (device->block->gdp)
3702 			blk_mq_run_hw_queues(device->block->gdp->queue, true);
3703 	}
3704 
3705 	if (!device->stopped)
3706 		wake_up(&generic_waitq);
3707 
3708 	return 1;
3709 }
3710 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3711 
3712 int dasd_generic_notify(struct ccw_device *cdev, int event)
3713 {
3714 	struct dasd_device *device;
3715 	int ret;
3716 
3717 	device = dasd_device_from_cdev_locked(cdev);
3718 	if (IS_ERR(device))
3719 		return 0;
3720 	ret = 0;
3721 	switch (event) {
3722 	case CIO_GONE:
3723 	case CIO_BOXED:
3724 	case CIO_NO_PATH:
3725 		dasd_path_no_path(device);
3726 		ret = dasd_generic_last_path_gone(device);
3727 		break;
3728 	case CIO_OPER:
3729 		ret = 1;
3730 		if (dasd_path_get_opm(device))
3731 			ret = dasd_generic_path_operational(device);
3732 		break;
3733 	}
3734 	dasd_put_device(device);
3735 	return ret;
3736 }
3737 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3738 
3739 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3740 {
3741 	struct dasd_device *device;
3742 	int chp, oldopm, hpfpm, ifccpm;
3743 
3744 	device = dasd_device_from_cdev_locked(cdev);
3745 	if (IS_ERR(device))
3746 		return;
3747 
3748 	oldopm = dasd_path_get_opm(device);
3749 	for (chp = 0; chp < 8; chp++) {
3750 		if (path_event[chp] & PE_PATH_GONE) {
3751 			dasd_path_notoper(device, chp);
3752 		}
3753 		if (path_event[chp] & PE_PATH_AVAILABLE) {
3754 			dasd_path_available(device, chp);
3755 			dasd_schedule_device_bh(device);
3756 		}
3757 		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3758 			if (!dasd_path_is_operational(device, chp) &&
3759 			    !dasd_path_need_verify(device, chp)) {
3760 				/*
3761 				 * we can not establish a pathgroup on an
3762 				 * unavailable path, so trigger a path
3763 				 * verification first
3764 				 */
3765 			dasd_path_available(device, chp);
3766 			dasd_schedule_device_bh(device);
3767 			}
3768 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3769 				      "Pathgroup re-established\n");
3770 			if (device->discipline->kick_validate)
3771 				device->discipline->kick_validate(device);
3772 		}
3773 		if (path_event[chp] & PE_PATH_FCES_EVENT) {
3774 			dasd_path_fcsec_update(device, chp);
3775 			dasd_schedule_device_bh(device);
3776 		}
3777 	}
3778 	hpfpm = dasd_path_get_hpfpm(device);
3779 	ifccpm = dasd_path_get_ifccpm(device);
3780 	if (!dasd_path_get_opm(device) && hpfpm) {
3781 		/*
3782 		 * device has no operational paths but at least one path is
3783 		 * disabled due to HPF errors
3784 		 * disable HPF at all and use the path(s) again
3785 		 */
3786 		if (device->discipline->disable_hpf)
3787 			device->discipline->disable_hpf(device);
3788 		dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3789 		dasd_path_set_tbvpm(device, hpfpm);
3790 		dasd_schedule_device_bh(device);
3791 		dasd_schedule_requeue(device);
3792 	} else if (!dasd_path_get_opm(device) && ifccpm) {
3793 		/*
3794 		 * device has no operational paths but at least one path is
3795 		 * disabled due to IFCC errors
3796 		 * trigger path verification on paths with IFCC errors
3797 		 */
3798 		dasd_path_set_tbvpm(device, ifccpm);
3799 		dasd_schedule_device_bh(device);
3800 	}
3801 	if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3802 		dev_warn(&device->cdev->dev,
3803 			 "No verified channel paths remain for the device\n");
3804 		DBF_DEV_EVENT(DBF_WARNING, device,
3805 			      "%s", "last verified path gone");
3806 		dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3807 		dasd_device_set_stop_bits(device,
3808 					  DASD_STOPPED_DC_WAIT);
3809 	}
3810 	dasd_put_device(device);
3811 }
3812 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3813 
3814 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3815 {
3816 	if (!dasd_path_get_opm(device) && lpm) {
3817 		dasd_path_set_opm(device, lpm);
3818 		dasd_generic_path_operational(device);
3819 	} else
3820 		dasd_path_add_opm(device, lpm);
3821 	return 0;
3822 }
3823 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3824 
3825 void dasd_generic_space_exhaust(struct dasd_device *device,
3826 				struct dasd_ccw_req *cqr)
3827 {
3828 	dasd_eer_write(device, NULL, DASD_EER_NOSPC);
3829 
3830 	if (device->state < DASD_STATE_BASIC)
3831 		return;
3832 
3833 	if (cqr->status == DASD_CQR_IN_IO ||
3834 	    cqr->status == DASD_CQR_CLEAR_PENDING) {
3835 		cqr->status = DASD_CQR_QUEUED;
3836 		cqr->retries++;
3837 	}
3838 	dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3839 	dasd_device_clear_timer(device);
3840 	dasd_schedule_device_bh(device);
3841 }
3842 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3843 
3844 void dasd_generic_space_avail(struct dasd_device *device)
3845 {
3846 	dev_info(&device->cdev->dev, "Extent pool space is available\n");
3847 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3848 
3849 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3850 	dasd_schedule_device_bh(device);
3851 
3852 	if (device->block) {
3853 		dasd_schedule_block_bh(device->block);
3854 		if (device->block->gdp)
3855 			blk_mq_run_hw_queues(device->block->gdp->queue, true);
3856 	}
3857 	if (!device->stopped)
3858 		wake_up(&generic_waitq);
3859 }
3860 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3861 
3862 /*
3863  * clear active requests and requeue them to block layer if possible
3864  */
3865 int dasd_generic_requeue_all_requests(struct dasd_device *device)
3866 {
3867 	struct list_head requeue_queue;
3868 	struct dasd_ccw_req *cqr, *n;
3869 	struct dasd_ccw_req *refers;
3870 	int rc;
3871 
3872 	INIT_LIST_HEAD(&requeue_queue);
3873 	spin_lock_irq(get_ccwdev_lock(device->cdev));
3874 	rc = 0;
3875 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3876 		/* Check status and move request to flush_queue */
3877 		if (cqr->status == DASD_CQR_IN_IO) {
3878 			rc = device->discipline->term_IO(cqr);
3879 			if (rc) {
3880 				/* unable to terminate requeust */
3881 				dev_err(&device->cdev->dev,
3882 					"Unable to terminate request %p "
3883 					"on suspend\n", cqr);
3884 				spin_unlock_irq(get_ccwdev_lock(device->cdev));
3885 				dasd_put_device(device);
3886 				return rc;
3887 			}
3888 		}
3889 		list_move_tail(&cqr->devlist, &requeue_queue);
3890 	}
3891 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
3892 
3893 	list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3894 		wait_event(dasd_flush_wq,
3895 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
3896 
3897 		/*
3898 		 * requeue requests to blocklayer will only work
3899 		 * for block device requests
3900 		 */
3901 		if (_dasd_requeue_request(cqr))
3902 			continue;
3903 
3904 		/* remove requests from device and block queue */
3905 		list_del_init(&cqr->devlist);
3906 		while (cqr->refers != NULL) {
3907 			refers = cqr->refers;
3908 			/* remove the request from the block queue */
3909 			list_del(&cqr->blocklist);
3910 			/* free the finished erp request */
3911 			dasd_free_erp_request(cqr, cqr->memdev);
3912 			cqr = refers;
3913 		}
3914 
3915 		/*
3916 		 * _dasd_requeue_request already checked for a valid
3917 		 * blockdevice, no need to check again
3918 		 * all erp requests (cqr->refers) have a cqr->block
3919 		 * pointer copy from the original cqr
3920 		 */
3921 		list_del_init(&cqr->blocklist);
3922 		cqr->block->base->discipline->free_cp(
3923 			cqr, (struct request *) cqr->callback_data);
3924 	}
3925 
3926 	/*
3927 	 * if requests remain then they are internal request
3928 	 * and go back to the device queue
3929 	 */
3930 	if (!list_empty(&requeue_queue)) {
3931 		/* move freeze_queue to start of the ccw_queue */
3932 		spin_lock_irq(get_ccwdev_lock(device->cdev));
3933 		list_splice_tail(&requeue_queue, &device->ccw_queue);
3934 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
3935 	}
3936 	dasd_schedule_device_bh(device);
3937 	return rc;
3938 }
3939 EXPORT_SYMBOL_GPL(dasd_generic_requeue_all_requests);
3940 
3941 static void do_requeue_requests(struct work_struct *work)
3942 {
3943 	struct dasd_device *device = container_of(work, struct dasd_device,
3944 						  requeue_requests);
3945 	dasd_generic_requeue_all_requests(device);
3946 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3947 	if (device->block)
3948 		dasd_schedule_block_bh(device->block);
3949 	dasd_put_device(device);
3950 }
3951 
3952 void dasd_schedule_requeue(struct dasd_device *device)
3953 {
3954 	dasd_get_device(device);
3955 	/* queue call to dasd_reload_device to the kernel event daemon. */
3956 	if (!schedule_work(&device->requeue_requests))
3957 		dasd_put_device(device);
3958 }
3959 EXPORT_SYMBOL(dasd_schedule_requeue);
3960 
3961 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3962 						   int rdc_buffer_size,
3963 						   int magic)
3964 {
3965 	struct dasd_ccw_req *cqr;
3966 	struct ccw1 *ccw;
3967 
3968 	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
3969 				   NULL);
3970 
3971 	if (IS_ERR(cqr)) {
3972 		/* internal error 13 - Allocating the RDC request failed*/
3973 		dev_err(&device->cdev->dev,
3974 			 "An error occurred in the DASD device driver, "
3975 			 "reason=%s\n", "13");
3976 		return cqr;
3977 	}
3978 
3979 	ccw = cqr->cpaddr;
3980 	ccw->cmd_code = CCW_CMD_RDC;
3981 	ccw->cda = (__u32)(addr_t) cqr->data;
3982 	ccw->flags = 0;
3983 	ccw->count = rdc_buffer_size;
3984 	cqr->startdev = device;
3985 	cqr->memdev = device;
3986 	cqr->expires = 10*HZ;
3987 	cqr->retries = 256;
3988 	cqr->buildclk = get_tod_clock();
3989 	cqr->status = DASD_CQR_FILLED;
3990 	return cqr;
3991 }
3992 
3993 
3994 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3995 				void *rdc_buffer, int rdc_buffer_size)
3996 {
3997 	int ret;
3998 	struct dasd_ccw_req *cqr;
3999 
4000 	cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4001 	if (IS_ERR(cqr))
4002 		return PTR_ERR(cqr);
4003 
4004 	ret = dasd_sleep_on(cqr);
4005 	if (ret == 0)
4006 		memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4007 	dasd_sfree_request(cqr, cqr->memdev);
4008 	return ret;
4009 }
4010 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4011 
4012 /*
4013  *   In command mode and transport mode we need to look for sense
4014  *   data in different places. The sense data itself is allways
4015  *   an array of 32 bytes, so we can unify the sense data access
4016  *   for both modes.
4017  */
4018 char *dasd_get_sense(struct irb *irb)
4019 {
4020 	struct tsb *tsb = NULL;
4021 	char *sense = NULL;
4022 
4023 	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4024 		if (irb->scsw.tm.tcw)
4025 			tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4026 					  irb->scsw.tm.tcw);
4027 		if (tsb && tsb->length == 64 && tsb->flags)
4028 			switch (tsb->flags & 0x07) {
4029 			case 1:	/* tsa_iostat */
4030 				sense = tsb->tsa.iostat.sense;
4031 				break;
4032 			case 2: /* tsa_ddpc */
4033 				sense = tsb->tsa.ddpc.sense;
4034 				break;
4035 			default:
4036 				/* currently we don't use interrogate data */
4037 				break;
4038 			}
4039 	} else if (irb->esw.esw0.erw.cons) {
4040 		sense = irb->ecw;
4041 	}
4042 	return sense;
4043 }
4044 EXPORT_SYMBOL_GPL(dasd_get_sense);
4045 
4046 void dasd_generic_shutdown(struct ccw_device *cdev)
4047 {
4048 	struct dasd_device *device;
4049 
4050 	device = dasd_device_from_cdev(cdev);
4051 	if (IS_ERR(device))
4052 		return;
4053 
4054 	if (device->block)
4055 		dasd_schedule_block_bh(device->block);
4056 
4057 	dasd_schedule_device_bh(device);
4058 
4059 	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4060 }
4061 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4062 
4063 static int __init dasd_init(void)
4064 {
4065 	int rc;
4066 
4067 	init_waitqueue_head(&dasd_init_waitq);
4068 	init_waitqueue_head(&dasd_flush_wq);
4069 	init_waitqueue_head(&generic_waitq);
4070 	init_waitqueue_head(&shutdown_waitq);
4071 
4072 	/* register 'common' DASD debug area, used for all DBF_XXX calls */
4073 	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4074 	if (dasd_debug_area == NULL) {
4075 		rc = -ENOMEM;
4076 		goto failed;
4077 	}
4078 	debug_register_view(dasd_debug_area, &debug_sprintf_view);
4079 	debug_set_level(dasd_debug_area, DBF_WARNING);
4080 
4081 	DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4082 
4083 	dasd_diag_discipline_pointer = NULL;
4084 
4085 	dasd_statistics_createroot();
4086 
4087 	rc = dasd_devmap_init();
4088 	if (rc)
4089 		goto failed;
4090 	rc = dasd_gendisk_init();
4091 	if (rc)
4092 		goto failed;
4093 	rc = dasd_parse();
4094 	if (rc)
4095 		goto failed;
4096 	rc = dasd_eer_init();
4097 	if (rc)
4098 		goto failed;
4099 #ifdef CONFIG_PROC_FS
4100 	rc = dasd_proc_init();
4101 	if (rc)
4102 		goto failed;
4103 #endif
4104 
4105 	return 0;
4106 failed:
4107 	pr_info("The DASD device driver could not be initialized\n");
4108 	dasd_exit();
4109 	return rc;
4110 }
4111 
4112 module_init(dasd_init);
4113 module_exit(dasd_exit);
4114