xref: /openbmc/linux/drivers/s390/block/dasd.c (revision f5ad1c74)
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 static unsigned int queue_depth = 32;
45 static unsigned int nr_hw_queues = 4;
46 
47 module_param(queue_depth, uint, 0444);
48 MODULE_PARM_DESC(queue_depth, "Default queue depth for new DASD devices");
49 
50 module_param(nr_hw_queues, uint, 0444);
51 MODULE_PARM_DESC(nr_hw_queues, "Default number of hardware queues for new DASD devices");
52 
53 /*
54  * SECTION: exported variables of dasd.c
55  */
56 debug_info_t *dasd_debug_area;
57 EXPORT_SYMBOL(dasd_debug_area);
58 static struct dentry *dasd_debugfs_root_entry;
59 struct dasd_discipline *dasd_diag_discipline_pointer;
60 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
61 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
62 
63 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
64 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
65 		   " Copyright IBM Corp. 2000");
66 MODULE_SUPPORTED_DEVICE("dasd");
67 MODULE_LICENSE("GPL");
68 
69 /*
70  * SECTION: prototypes for static functions of dasd.c
71  */
72 static int  dasd_alloc_queue(struct dasd_block *);
73 static void dasd_free_queue(struct dasd_block *);
74 static int dasd_flush_block_queue(struct dasd_block *);
75 static void dasd_device_tasklet(unsigned long);
76 static void dasd_block_tasklet(unsigned long);
77 static void do_kick_device(struct work_struct *);
78 static void do_reload_device(struct work_struct *);
79 static void do_requeue_requests(struct work_struct *);
80 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
81 static void dasd_device_timeout(struct timer_list *);
82 static void dasd_block_timeout(struct timer_list *);
83 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
84 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
85 static void dasd_profile_exit(struct dasd_profile *);
86 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
87 static void dasd_hosts_exit(struct dasd_device *);
88 
89 /*
90  * SECTION: Operations on the device structure.
91  */
92 static wait_queue_head_t dasd_init_waitq;
93 static wait_queue_head_t dasd_flush_wq;
94 static wait_queue_head_t generic_waitq;
95 static wait_queue_head_t shutdown_waitq;
96 
97 /*
98  * Allocate memory for a new device structure.
99  */
100 struct dasd_device *dasd_alloc_device(void)
101 {
102 	struct dasd_device *device;
103 
104 	device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
105 	if (!device)
106 		return ERR_PTR(-ENOMEM);
107 
108 	/* Get two pages for normal block device operations. */
109 	device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
110 	if (!device->ccw_mem) {
111 		kfree(device);
112 		return ERR_PTR(-ENOMEM);
113 	}
114 	/* Get one page for error recovery. */
115 	device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
116 	if (!device->erp_mem) {
117 		free_pages((unsigned long) device->ccw_mem, 1);
118 		kfree(device);
119 		return ERR_PTR(-ENOMEM);
120 	}
121 	/* Get two pages for ese format. */
122 	device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
123 	if (!device->ese_mem) {
124 		free_page((unsigned long) device->erp_mem);
125 		free_pages((unsigned long) device->ccw_mem, 1);
126 		kfree(device);
127 		return ERR_PTR(-ENOMEM);
128 	}
129 
130 	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
131 	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
132 	dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
133 	spin_lock_init(&device->mem_lock);
134 	atomic_set(&device->tasklet_scheduled, 0);
135 	tasklet_init(&device->tasklet, dasd_device_tasklet,
136 		     (unsigned long) device);
137 	INIT_LIST_HEAD(&device->ccw_queue);
138 	timer_setup(&device->timer, dasd_device_timeout, 0);
139 	INIT_WORK(&device->kick_work, do_kick_device);
140 	INIT_WORK(&device->reload_device, do_reload_device);
141 	INIT_WORK(&device->requeue_requests, do_requeue_requests);
142 	device->state = DASD_STATE_NEW;
143 	device->target = DASD_STATE_NEW;
144 	mutex_init(&device->state_mutex);
145 	spin_lock_init(&device->profile.lock);
146 	return device;
147 }
148 
149 /*
150  * Free memory of a device structure.
151  */
152 void dasd_free_device(struct dasd_device *device)
153 {
154 	kfree(device->private);
155 	free_pages((unsigned long) device->ese_mem, 1);
156 	free_page((unsigned long) device->erp_mem);
157 	free_pages((unsigned long) device->ccw_mem, 1);
158 	kfree(device);
159 }
160 
161 /*
162  * Allocate memory for a new device structure.
163  */
164 struct dasd_block *dasd_alloc_block(void)
165 {
166 	struct dasd_block *block;
167 
168 	block = kzalloc(sizeof(*block), GFP_ATOMIC);
169 	if (!block)
170 		return ERR_PTR(-ENOMEM);
171 	/* open_count = 0 means device online but not in use */
172 	atomic_set(&block->open_count, -1);
173 
174 	atomic_set(&block->tasklet_scheduled, 0);
175 	tasklet_init(&block->tasklet, dasd_block_tasklet,
176 		     (unsigned long) block);
177 	INIT_LIST_HEAD(&block->ccw_queue);
178 	spin_lock_init(&block->queue_lock);
179 	INIT_LIST_HEAD(&block->format_list);
180 	spin_lock_init(&block->format_lock);
181 	timer_setup(&block->timer, dasd_block_timeout, 0);
182 	spin_lock_init(&block->profile.lock);
183 
184 	return block;
185 }
186 EXPORT_SYMBOL_GPL(dasd_alloc_block);
187 
188 /*
189  * Free memory of a device structure.
190  */
191 void dasd_free_block(struct dasd_block *block)
192 {
193 	kfree(block);
194 }
195 EXPORT_SYMBOL_GPL(dasd_free_block);
196 
197 /*
198  * Make a new device known to the system.
199  */
200 static int dasd_state_new_to_known(struct dasd_device *device)
201 {
202 	int rc;
203 
204 	/*
205 	 * As long as the device is not in state DASD_STATE_NEW we want to
206 	 * keep the reference count > 0.
207 	 */
208 	dasd_get_device(device);
209 
210 	if (device->block) {
211 		rc = dasd_alloc_queue(device->block);
212 		if (rc) {
213 			dasd_put_device(device);
214 			return rc;
215 		}
216 	}
217 	device->state = DASD_STATE_KNOWN;
218 	return 0;
219 }
220 
221 /*
222  * Let the system forget about a device.
223  */
224 static int dasd_state_known_to_new(struct dasd_device *device)
225 {
226 	/* Disable extended error reporting for this device. */
227 	dasd_eer_disable(device);
228 	device->state = DASD_STATE_NEW;
229 
230 	if (device->block)
231 		dasd_free_queue(device->block);
232 
233 	/* Give up reference we took in dasd_state_new_to_known. */
234 	dasd_put_device(device);
235 	return 0;
236 }
237 
238 static struct dentry *dasd_debugfs_setup(const char *name,
239 					 struct dentry *base_dentry)
240 {
241 	struct dentry *pde;
242 
243 	if (!base_dentry)
244 		return NULL;
245 	pde = debugfs_create_dir(name, base_dentry);
246 	if (!pde || IS_ERR(pde))
247 		return NULL;
248 	return pde;
249 }
250 
251 /*
252  * Request the irq line for the device.
253  */
254 static int dasd_state_known_to_basic(struct dasd_device *device)
255 {
256 	struct dasd_block *block = device->block;
257 	int rc = 0;
258 
259 	/* Allocate and register gendisk structure. */
260 	if (block) {
261 		rc = dasd_gendisk_alloc(block);
262 		if (rc)
263 			return rc;
264 		block->debugfs_dentry =
265 			dasd_debugfs_setup(block->gdp->disk_name,
266 					   dasd_debugfs_root_entry);
267 		dasd_profile_init(&block->profile, block->debugfs_dentry);
268 		if (dasd_global_profile_level == DASD_PROFILE_ON)
269 			dasd_profile_on(&device->block->profile);
270 	}
271 	device->debugfs_dentry =
272 		dasd_debugfs_setup(dev_name(&device->cdev->dev),
273 				   dasd_debugfs_root_entry);
274 	dasd_profile_init(&device->profile, device->debugfs_dentry);
275 	dasd_hosts_init(device->debugfs_dentry, device);
276 
277 	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
278 	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
279 					    8 * sizeof(long));
280 	debug_register_view(device->debug_area, &debug_sprintf_view);
281 	debug_set_level(device->debug_area, DBF_WARNING);
282 	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
283 
284 	device->state = DASD_STATE_BASIC;
285 
286 	return rc;
287 }
288 
289 /*
290  * Release the irq line for the device. Terminate any running i/o.
291  */
292 static int dasd_state_basic_to_known(struct dasd_device *device)
293 {
294 	int rc;
295 
296 	if (device->discipline->basic_to_known) {
297 		rc = device->discipline->basic_to_known(device);
298 		if (rc)
299 			return rc;
300 	}
301 
302 	if (device->block) {
303 		dasd_profile_exit(&device->block->profile);
304 		debugfs_remove(device->block->debugfs_dentry);
305 		dasd_gendisk_free(device->block);
306 		dasd_block_clear_timer(device->block);
307 	}
308 	rc = dasd_flush_device_queue(device);
309 	if (rc)
310 		return rc;
311 	dasd_device_clear_timer(device);
312 	dasd_profile_exit(&device->profile);
313 	dasd_hosts_exit(device);
314 	debugfs_remove(device->debugfs_dentry);
315 	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
316 	if (device->debug_area != NULL) {
317 		debug_unregister(device->debug_area);
318 		device->debug_area = NULL;
319 	}
320 	device->state = DASD_STATE_KNOWN;
321 	return 0;
322 }
323 
324 /*
325  * Do the initial analysis. The do_analysis function may return
326  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
327  * until the discipline decides to continue the startup sequence
328  * by calling the function dasd_change_state. The eckd disciplines
329  * uses this to start a ccw that detects the format. The completion
330  * interrupt for this detection ccw uses the kernel event daemon to
331  * trigger the call to dasd_change_state. All this is done in the
332  * discipline code, see dasd_eckd.c.
333  * After the analysis ccw is done (do_analysis returned 0) the block
334  * device is setup.
335  * In case the analysis returns an error, the device setup is stopped
336  * (a fake disk was already added to allow formatting).
337  */
338 static int dasd_state_basic_to_ready(struct dasd_device *device)
339 {
340 	int rc;
341 	struct dasd_block *block;
342 	struct gendisk *disk;
343 
344 	rc = 0;
345 	block = device->block;
346 	/* make disk known with correct capacity */
347 	if (block) {
348 		if (block->base->discipline->do_analysis != NULL)
349 			rc = block->base->discipline->do_analysis(block);
350 		if (rc) {
351 			if (rc != -EAGAIN) {
352 				device->state = DASD_STATE_UNFMT;
353 				disk = device->block->gdp;
354 				kobject_uevent(&disk_to_dev(disk)->kobj,
355 					       KOBJ_CHANGE);
356 				goto out;
357 			}
358 			return rc;
359 		}
360 		if (device->discipline->setup_blk_queue)
361 			device->discipline->setup_blk_queue(block);
362 		set_capacity(block->gdp,
363 			     block->blocks << block->s2b_shift);
364 		device->state = DASD_STATE_READY;
365 		rc = dasd_scan_partitions(block);
366 		if (rc) {
367 			device->state = DASD_STATE_BASIC;
368 			return rc;
369 		}
370 	} else {
371 		device->state = DASD_STATE_READY;
372 	}
373 out:
374 	if (device->discipline->basic_to_ready)
375 		rc = device->discipline->basic_to_ready(device);
376 	return rc;
377 }
378 
379 static inline
380 int _wait_for_empty_queues(struct dasd_device *device)
381 {
382 	if (device->block)
383 		return list_empty(&device->ccw_queue) &&
384 			list_empty(&device->block->ccw_queue);
385 	else
386 		return list_empty(&device->ccw_queue);
387 }
388 
389 /*
390  * Remove device from block device layer. Destroy dirty buffers.
391  * Forget format information. Check if the target level is basic
392  * and if it is create fake disk for formatting.
393  */
394 static int dasd_state_ready_to_basic(struct dasd_device *device)
395 {
396 	int rc;
397 
398 	device->state = DASD_STATE_BASIC;
399 	if (device->block) {
400 		struct dasd_block *block = device->block;
401 		rc = dasd_flush_block_queue(block);
402 		if (rc) {
403 			device->state = DASD_STATE_READY;
404 			return rc;
405 		}
406 		dasd_destroy_partitions(block);
407 		block->blocks = 0;
408 		block->bp_block = 0;
409 		block->s2b_shift = 0;
410 	}
411 	return 0;
412 }
413 
414 /*
415  * Back to basic.
416  */
417 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
418 {
419 	device->state = DASD_STATE_BASIC;
420 	return 0;
421 }
422 
423 /*
424  * Make the device online and schedule the bottom half to start
425  * the requeueing of requests from the linux request queue to the
426  * ccw queue.
427  */
428 static int
429 dasd_state_ready_to_online(struct dasd_device * device)
430 {
431 	struct gendisk *disk;
432 	struct disk_part_iter piter;
433 	struct hd_struct *part;
434 
435 	device->state = DASD_STATE_ONLINE;
436 	if (device->block) {
437 		dasd_schedule_block_bh(device->block);
438 		if ((device->features & DASD_FEATURE_USERAW)) {
439 			disk = device->block->gdp;
440 			kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
441 			return 0;
442 		}
443 		disk = device->block->bdev->bd_disk;
444 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
445 		while ((part = disk_part_iter_next(&piter)))
446 			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
447 		disk_part_iter_exit(&piter);
448 	}
449 	return 0;
450 }
451 
452 /*
453  * Stop the requeueing of requests again.
454  */
455 static int dasd_state_online_to_ready(struct dasd_device *device)
456 {
457 	int rc;
458 	struct gendisk *disk;
459 	struct disk_part_iter piter;
460 	struct hd_struct *part;
461 
462 	if (device->discipline->online_to_ready) {
463 		rc = device->discipline->online_to_ready(device);
464 		if (rc)
465 			return rc;
466 	}
467 
468 	device->state = DASD_STATE_READY;
469 	if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
470 		disk = device->block->bdev->bd_disk;
471 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
472 		while ((part = disk_part_iter_next(&piter)))
473 			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
474 		disk_part_iter_exit(&piter);
475 	}
476 	return 0;
477 }
478 
479 /*
480  * Device startup state changes.
481  */
482 static int dasd_increase_state(struct dasd_device *device)
483 {
484 	int rc;
485 
486 	rc = 0;
487 	if (device->state == DASD_STATE_NEW &&
488 	    device->target >= DASD_STATE_KNOWN)
489 		rc = dasd_state_new_to_known(device);
490 
491 	if (!rc &&
492 	    device->state == DASD_STATE_KNOWN &&
493 	    device->target >= DASD_STATE_BASIC)
494 		rc = dasd_state_known_to_basic(device);
495 
496 	if (!rc &&
497 	    device->state == DASD_STATE_BASIC &&
498 	    device->target >= DASD_STATE_READY)
499 		rc = dasd_state_basic_to_ready(device);
500 
501 	if (!rc &&
502 	    device->state == DASD_STATE_UNFMT &&
503 	    device->target > DASD_STATE_UNFMT)
504 		rc = -EPERM;
505 
506 	if (!rc &&
507 	    device->state == DASD_STATE_READY &&
508 	    device->target >= DASD_STATE_ONLINE)
509 		rc = dasd_state_ready_to_online(device);
510 
511 	return rc;
512 }
513 
514 /*
515  * Device shutdown state changes.
516  */
517 static int dasd_decrease_state(struct dasd_device *device)
518 {
519 	int rc;
520 
521 	rc = 0;
522 	if (device->state == DASD_STATE_ONLINE &&
523 	    device->target <= DASD_STATE_READY)
524 		rc = dasd_state_online_to_ready(device);
525 
526 	if (!rc &&
527 	    device->state == DASD_STATE_READY &&
528 	    device->target <= DASD_STATE_BASIC)
529 		rc = dasd_state_ready_to_basic(device);
530 
531 	if (!rc &&
532 	    device->state == DASD_STATE_UNFMT &&
533 	    device->target <= DASD_STATE_BASIC)
534 		rc = dasd_state_unfmt_to_basic(device);
535 
536 	if (!rc &&
537 	    device->state == DASD_STATE_BASIC &&
538 	    device->target <= DASD_STATE_KNOWN)
539 		rc = dasd_state_basic_to_known(device);
540 
541 	if (!rc &&
542 	    device->state == DASD_STATE_KNOWN &&
543 	    device->target <= DASD_STATE_NEW)
544 		rc = dasd_state_known_to_new(device);
545 
546 	return rc;
547 }
548 
549 /*
550  * This is the main startup/shutdown routine.
551  */
552 static void dasd_change_state(struct dasd_device *device)
553 {
554 	int rc;
555 
556 	if (device->state == device->target)
557 		/* Already where we want to go today... */
558 		return;
559 	if (device->state < device->target)
560 		rc = dasd_increase_state(device);
561 	else
562 		rc = dasd_decrease_state(device);
563 	if (rc == -EAGAIN)
564 		return;
565 	if (rc)
566 		device->target = device->state;
567 
568 	/* let user-space know that the device status changed */
569 	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
570 
571 	if (device->state == device->target)
572 		wake_up(&dasd_init_waitq);
573 }
574 
575 /*
576  * Kick starter for devices that did not complete the startup/shutdown
577  * procedure or were sleeping because of a pending state.
578  * dasd_kick_device will schedule a call do do_kick_device to the kernel
579  * event daemon.
580  */
581 static void do_kick_device(struct work_struct *work)
582 {
583 	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
584 	mutex_lock(&device->state_mutex);
585 	dasd_change_state(device);
586 	mutex_unlock(&device->state_mutex);
587 	dasd_schedule_device_bh(device);
588 	dasd_put_device(device);
589 }
590 
591 void dasd_kick_device(struct dasd_device *device)
592 {
593 	dasd_get_device(device);
594 	/* queue call to dasd_kick_device to the kernel event daemon. */
595 	if (!schedule_work(&device->kick_work))
596 		dasd_put_device(device);
597 }
598 EXPORT_SYMBOL(dasd_kick_device);
599 
600 /*
601  * dasd_reload_device will schedule a call do do_reload_device to the kernel
602  * event daemon.
603  */
604 static void do_reload_device(struct work_struct *work)
605 {
606 	struct dasd_device *device = container_of(work, struct dasd_device,
607 						  reload_device);
608 	device->discipline->reload(device);
609 	dasd_put_device(device);
610 }
611 
612 void dasd_reload_device(struct dasd_device *device)
613 {
614 	dasd_get_device(device);
615 	/* queue call to dasd_reload_device to the kernel event daemon. */
616 	if (!schedule_work(&device->reload_device))
617 		dasd_put_device(device);
618 }
619 EXPORT_SYMBOL(dasd_reload_device);
620 
621 /*
622  * Set the target state for a device and starts the state change.
623  */
624 void dasd_set_target_state(struct dasd_device *device, int target)
625 {
626 	dasd_get_device(device);
627 	mutex_lock(&device->state_mutex);
628 	/* If we are in probeonly mode stop at DASD_STATE_READY. */
629 	if (dasd_probeonly && target > DASD_STATE_READY)
630 		target = DASD_STATE_READY;
631 	if (device->target != target) {
632 		if (device->state == target)
633 			wake_up(&dasd_init_waitq);
634 		device->target = target;
635 	}
636 	if (device->state != device->target)
637 		dasd_change_state(device);
638 	mutex_unlock(&device->state_mutex);
639 	dasd_put_device(device);
640 }
641 EXPORT_SYMBOL(dasd_set_target_state);
642 
643 /*
644  * Enable devices with device numbers in [from..to].
645  */
646 static inline int _wait_for_device(struct dasd_device *device)
647 {
648 	return (device->state == device->target);
649 }
650 
651 void dasd_enable_device(struct dasd_device *device)
652 {
653 	dasd_set_target_state(device, DASD_STATE_ONLINE);
654 	if (device->state <= DASD_STATE_KNOWN)
655 		/* No discipline for device found. */
656 		dasd_set_target_state(device, DASD_STATE_NEW);
657 	/* Now wait for the devices to come up. */
658 	wait_event(dasd_init_waitq, _wait_for_device(device));
659 
660 	dasd_reload_device(device);
661 	if (device->discipline->kick_validate)
662 		device->discipline->kick_validate(device);
663 }
664 EXPORT_SYMBOL(dasd_enable_device);
665 
666 /*
667  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
668  */
669 
670 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
671 
672 #ifdef CONFIG_DASD_PROFILE
673 struct dasd_profile dasd_global_profile = {
674 	.lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
675 };
676 static struct dentry *dasd_debugfs_global_entry;
677 
678 /*
679  * Add profiling information for cqr before execution.
680  */
681 static void dasd_profile_start(struct dasd_block *block,
682 			       struct dasd_ccw_req *cqr,
683 			       struct request *req)
684 {
685 	struct list_head *l;
686 	unsigned int counter;
687 	struct dasd_device *device;
688 
689 	/* count the length of the chanq for statistics */
690 	counter = 0;
691 	if (dasd_global_profile_level || block->profile.data)
692 		list_for_each(l, &block->ccw_queue)
693 			if (++counter >= 31)
694 				break;
695 
696 	spin_lock(&dasd_global_profile.lock);
697 	if (dasd_global_profile.data) {
698 		dasd_global_profile.data->dasd_io_nr_req[counter]++;
699 		if (rq_data_dir(req) == READ)
700 			dasd_global_profile.data->dasd_read_nr_req[counter]++;
701 	}
702 	spin_unlock(&dasd_global_profile.lock);
703 
704 	spin_lock(&block->profile.lock);
705 	if (block->profile.data) {
706 		block->profile.data->dasd_io_nr_req[counter]++;
707 		if (rq_data_dir(req) == READ)
708 			block->profile.data->dasd_read_nr_req[counter]++;
709 	}
710 	spin_unlock(&block->profile.lock);
711 
712 	/*
713 	 * We count the request for the start device, even though it may run on
714 	 * some other device due to error recovery. This way we make sure that
715 	 * we count each request only once.
716 	 */
717 	device = cqr->startdev;
718 	if (device->profile.data) {
719 		counter = 1; /* request is not yet queued on the start device */
720 		list_for_each(l, &device->ccw_queue)
721 			if (++counter >= 31)
722 				break;
723 	}
724 	spin_lock(&device->profile.lock);
725 	if (device->profile.data) {
726 		device->profile.data->dasd_io_nr_req[counter]++;
727 		if (rq_data_dir(req) == READ)
728 			device->profile.data->dasd_read_nr_req[counter]++;
729 	}
730 	spin_unlock(&device->profile.lock);
731 }
732 
733 /*
734  * Add profiling information for cqr after execution.
735  */
736 
737 #define dasd_profile_counter(value, index)			   \
738 {								   \
739 	for (index = 0; index < 31 && value >> (2+index); index++) \
740 		;						   \
741 }
742 
743 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
744 				      int is_alias,
745 				      int is_tpm,
746 				      int is_read,
747 				      long sectors,
748 				      int sectors_ind,
749 				      int tottime_ind,
750 				      int tottimeps_ind,
751 				      int strtime_ind,
752 				      int irqtime_ind,
753 				      int irqtimeps_ind,
754 				      int endtime_ind)
755 {
756 	/* in case of an overflow, reset the whole profile */
757 	if (data->dasd_io_reqs == UINT_MAX) {
758 			memset(data, 0, sizeof(*data));
759 			ktime_get_real_ts64(&data->starttod);
760 	}
761 	data->dasd_io_reqs++;
762 	data->dasd_io_sects += sectors;
763 	if (is_alias)
764 		data->dasd_io_alias++;
765 	if (is_tpm)
766 		data->dasd_io_tpm++;
767 
768 	data->dasd_io_secs[sectors_ind]++;
769 	data->dasd_io_times[tottime_ind]++;
770 	data->dasd_io_timps[tottimeps_ind]++;
771 	data->dasd_io_time1[strtime_ind]++;
772 	data->dasd_io_time2[irqtime_ind]++;
773 	data->dasd_io_time2ps[irqtimeps_ind]++;
774 	data->dasd_io_time3[endtime_ind]++;
775 
776 	if (is_read) {
777 		data->dasd_read_reqs++;
778 		data->dasd_read_sects += sectors;
779 		if (is_alias)
780 			data->dasd_read_alias++;
781 		if (is_tpm)
782 			data->dasd_read_tpm++;
783 		data->dasd_read_secs[sectors_ind]++;
784 		data->dasd_read_times[tottime_ind]++;
785 		data->dasd_read_time1[strtime_ind]++;
786 		data->dasd_read_time2[irqtime_ind]++;
787 		data->dasd_read_time3[endtime_ind]++;
788 	}
789 }
790 
791 static void dasd_profile_end(struct dasd_block *block,
792 			     struct dasd_ccw_req *cqr,
793 			     struct request *req)
794 {
795 	unsigned long strtime, irqtime, endtime, tottime;
796 	unsigned long tottimeps, sectors;
797 	struct dasd_device *device;
798 	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
799 	int irqtime_ind, irqtimeps_ind, endtime_ind;
800 	struct dasd_profile_info *data;
801 
802 	device = cqr->startdev;
803 	if (!(dasd_global_profile_level ||
804 	      block->profile.data ||
805 	      device->profile.data))
806 		return;
807 
808 	sectors = blk_rq_sectors(req);
809 	if (!cqr->buildclk || !cqr->startclk ||
810 	    !cqr->stopclk || !cqr->endclk ||
811 	    !sectors)
812 		return;
813 
814 	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
815 	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
816 	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
817 	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
818 	tottimeps = tottime / sectors;
819 
820 	dasd_profile_counter(sectors, sectors_ind);
821 	dasd_profile_counter(tottime, tottime_ind);
822 	dasd_profile_counter(tottimeps, tottimeps_ind);
823 	dasd_profile_counter(strtime, strtime_ind);
824 	dasd_profile_counter(irqtime, irqtime_ind);
825 	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
826 	dasd_profile_counter(endtime, endtime_ind);
827 
828 	spin_lock(&dasd_global_profile.lock);
829 	if (dasd_global_profile.data) {
830 		data = dasd_global_profile.data;
831 		data->dasd_sum_times += tottime;
832 		data->dasd_sum_time_str += strtime;
833 		data->dasd_sum_time_irq += irqtime;
834 		data->dasd_sum_time_end += endtime;
835 		dasd_profile_end_add_data(dasd_global_profile.data,
836 					  cqr->startdev != block->base,
837 					  cqr->cpmode == 1,
838 					  rq_data_dir(req) == READ,
839 					  sectors, sectors_ind, tottime_ind,
840 					  tottimeps_ind, strtime_ind,
841 					  irqtime_ind, irqtimeps_ind,
842 					  endtime_ind);
843 	}
844 	spin_unlock(&dasd_global_profile.lock);
845 
846 	spin_lock(&block->profile.lock);
847 	if (block->profile.data) {
848 		data = block->profile.data;
849 		data->dasd_sum_times += tottime;
850 		data->dasd_sum_time_str += strtime;
851 		data->dasd_sum_time_irq += irqtime;
852 		data->dasd_sum_time_end += endtime;
853 		dasd_profile_end_add_data(block->profile.data,
854 					  cqr->startdev != block->base,
855 					  cqr->cpmode == 1,
856 					  rq_data_dir(req) == READ,
857 					  sectors, sectors_ind, tottime_ind,
858 					  tottimeps_ind, strtime_ind,
859 					  irqtime_ind, irqtimeps_ind,
860 					  endtime_ind);
861 	}
862 	spin_unlock(&block->profile.lock);
863 
864 	spin_lock(&device->profile.lock);
865 	if (device->profile.data) {
866 		data = device->profile.data;
867 		data->dasd_sum_times += tottime;
868 		data->dasd_sum_time_str += strtime;
869 		data->dasd_sum_time_irq += irqtime;
870 		data->dasd_sum_time_end += endtime;
871 		dasd_profile_end_add_data(device->profile.data,
872 					  cqr->startdev != block->base,
873 					  cqr->cpmode == 1,
874 					  rq_data_dir(req) == READ,
875 					  sectors, sectors_ind, tottime_ind,
876 					  tottimeps_ind, strtime_ind,
877 					  irqtime_ind, irqtimeps_ind,
878 					  endtime_ind);
879 	}
880 	spin_unlock(&device->profile.lock);
881 }
882 
883 void dasd_profile_reset(struct dasd_profile *profile)
884 {
885 	struct dasd_profile_info *data;
886 
887 	spin_lock_bh(&profile->lock);
888 	data = profile->data;
889 	if (!data) {
890 		spin_unlock_bh(&profile->lock);
891 		return;
892 	}
893 	memset(data, 0, sizeof(*data));
894 	ktime_get_real_ts64(&data->starttod);
895 	spin_unlock_bh(&profile->lock);
896 }
897 
898 int dasd_profile_on(struct dasd_profile *profile)
899 {
900 	struct dasd_profile_info *data;
901 
902 	data = kzalloc(sizeof(*data), GFP_KERNEL);
903 	if (!data)
904 		return -ENOMEM;
905 	spin_lock_bh(&profile->lock);
906 	if (profile->data) {
907 		spin_unlock_bh(&profile->lock);
908 		kfree(data);
909 		return 0;
910 	}
911 	ktime_get_real_ts64(&data->starttod);
912 	profile->data = data;
913 	spin_unlock_bh(&profile->lock);
914 	return 0;
915 }
916 
917 void dasd_profile_off(struct dasd_profile *profile)
918 {
919 	spin_lock_bh(&profile->lock);
920 	kfree(profile->data);
921 	profile->data = NULL;
922 	spin_unlock_bh(&profile->lock);
923 }
924 
925 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
926 {
927 	char *buffer;
928 
929 	buffer = vmalloc(user_len + 1);
930 	if (buffer == NULL)
931 		return ERR_PTR(-ENOMEM);
932 	if (copy_from_user(buffer, user_buf, user_len) != 0) {
933 		vfree(buffer);
934 		return ERR_PTR(-EFAULT);
935 	}
936 	/* got the string, now strip linefeed. */
937 	if (buffer[user_len - 1] == '\n')
938 		buffer[user_len - 1] = 0;
939 	else
940 		buffer[user_len] = 0;
941 	return buffer;
942 }
943 
944 static ssize_t dasd_stats_write(struct file *file,
945 				const char __user *user_buf,
946 				size_t user_len, loff_t *pos)
947 {
948 	char *buffer, *str;
949 	int rc;
950 	struct seq_file *m = (struct seq_file *)file->private_data;
951 	struct dasd_profile *prof = m->private;
952 
953 	if (user_len > 65536)
954 		user_len = 65536;
955 	buffer = dasd_get_user_string(user_buf, user_len);
956 	if (IS_ERR(buffer))
957 		return PTR_ERR(buffer);
958 
959 	str = skip_spaces(buffer);
960 	rc = user_len;
961 	if (strncmp(str, "reset", 5) == 0) {
962 		dasd_profile_reset(prof);
963 	} else if (strncmp(str, "on", 2) == 0) {
964 		rc = dasd_profile_on(prof);
965 		if (rc)
966 			goto out;
967 		rc = user_len;
968 		if (prof == &dasd_global_profile) {
969 			dasd_profile_reset(prof);
970 			dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
971 		}
972 	} else if (strncmp(str, "off", 3) == 0) {
973 		if (prof == &dasd_global_profile)
974 			dasd_global_profile_level = DASD_PROFILE_OFF;
975 		dasd_profile_off(prof);
976 	} else
977 		rc = -EINVAL;
978 out:
979 	vfree(buffer);
980 	return rc;
981 }
982 
983 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
984 {
985 	int i;
986 
987 	for (i = 0; i < 32; i++)
988 		seq_printf(m, "%u ", array[i]);
989 	seq_putc(m, '\n');
990 }
991 
992 static void dasd_stats_seq_print(struct seq_file *m,
993 				 struct dasd_profile_info *data)
994 {
995 	seq_printf(m, "start_time %lld.%09ld\n",
996 		   (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
997 	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
998 	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
999 	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1000 	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1001 	seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1002 		   data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1003 	seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1004 		   data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1005 	seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1006 		   data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1007 	seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1008 		   data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1009 	seq_puts(m, "histogram_sectors ");
1010 	dasd_stats_array(m, data->dasd_io_secs);
1011 	seq_puts(m, "histogram_io_times ");
1012 	dasd_stats_array(m, data->dasd_io_times);
1013 	seq_puts(m, "histogram_io_times_weighted ");
1014 	dasd_stats_array(m, data->dasd_io_timps);
1015 	seq_puts(m, "histogram_time_build_to_ssch ");
1016 	dasd_stats_array(m, data->dasd_io_time1);
1017 	seq_puts(m, "histogram_time_ssch_to_irq ");
1018 	dasd_stats_array(m, data->dasd_io_time2);
1019 	seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1020 	dasd_stats_array(m, data->dasd_io_time2ps);
1021 	seq_puts(m, "histogram_time_irq_to_end ");
1022 	dasd_stats_array(m, data->dasd_io_time3);
1023 	seq_puts(m, "histogram_ccw_queue_length ");
1024 	dasd_stats_array(m, data->dasd_io_nr_req);
1025 	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1026 	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1027 	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1028 	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1029 	seq_puts(m, "histogram_read_sectors ");
1030 	dasd_stats_array(m, data->dasd_read_secs);
1031 	seq_puts(m, "histogram_read_times ");
1032 	dasd_stats_array(m, data->dasd_read_times);
1033 	seq_puts(m, "histogram_read_time_build_to_ssch ");
1034 	dasd_stats_array(m, data->dasd_read_time1);
1035 	seq_puts(m, "histogram_read_time_ssch_to_irq ");
1036 	dasd_stats_array(m, data->dasd_read_time2);
1037 	seq_puts(m, "histogram_read_time_irq_to_end ");
1038 	dasd_stats_array(m, data->dasd_read_time3);
1039 	seq_puts(m, "histogram_read_ccw_queue_length ");
1040 	dasd_stats_array(m, data->dasd_read_nr_req);
1041 }
1042 
1043 static int dasd_stats_show(struct seq_file *m, void *v)
1044 {
1045 	struct dasd_profile *profile;
1046 	struct dasd_profile_info *data;
1047 
1048 	profile = m->private;
1049 	spin_lock_bh(&profile->lock);
1050 	data = profile->data;
1051 	if (!data) {
1052 		spin_unlock_bh(&profile->lock);
1053 		seq_puts(m, "disabled\n");
1054 		return 0;
1055 	}
1056 	dasd_stats_seq_print(m, data);
1057 	spin_unlock_bh(&profile->lock);
1058 	return 0;
1059 }
1060 
1061 static int dasd_stats_open(struct inode *inode, struct file *file)
1062 {
1063 	struct dasd_profile *profile = inode->i_private;
1064 	return single_open(file, dasd_stats_show, profile);
1065 }
1066 
1067 static const struct file_operations dasd_stats_raw_fops = {
1068 	.owner		= THIS_MODULE,
1069 	.open		= dasd_stats_open,
1070 	.read		= seq_read,
1071 	.llseek		= seq_lseek,
1072 	.release	= single_release,
1073 	.write		= dasd_stats_write,
1074 };
1075 
1076 static void dasd_profile_init(struct dasd_profile *profile,
1077 			      struct dentry *base_dentry)
1078 {
1079 	umode_t mode;
1080 	struct dentry *pde;
1081 
1082 	if (!base_dentry)
1083 		return;
1084 	profile->dentry = NULL;
1085 	profile->data = NULL;
1086 	mode = (S_IRUSR | S_IWUSR | S_IFREG);
1087 	pde = debugfs_create_file("statistics", mode, base_dentry,
1088 				  profile, &dasd_stats_raw_fops);
1089 	if (pde && !IS_ERR(pde))
1090 		profile->dentry = pde;
1091 	return;
1092 }
1093 
1094 static void dasd_profile_exit(struct dasd_profile *profile)
1095 {
1096 	dasd_profile_off(profile);
1097 	debugfs_remove(profile->dentry);
1098 	profile->dentry = NULL;
1099 }
1100 
1101 static void dasd_statistics_removeroot(void)
1102 {
1103 	dasd_global_profile_level = DASD_PROFILE_OFF;
1104 	dasd_profile_exit(&dasd_global_profile);
1105 	debugfs_remove(dasd_debugfs_global_entry);
1106 	debugfs_remove(dasd_debugfs_root_entry);
1107 }
1108 
1109 static void dasd_statistics_createroot(void)
1110 {
1111 	struct dentry *pde;
1112 
1113 	dasd_debugfs_root_entry = NULL;
1114 	pde = debugfs_create_dir("dasd", NULL);
1115 	if (!pde || IS_ERR(pde))
1116 		goto error;
1117 	dasd_debugfs_root_entry = pde;
1118 	pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1119 	if (!pde || IS_ERR(pde))
1120 		goto error;
1121 	dasd_debugfs_global_entry = pde;
1122 	dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1123 	return;
1124 
1125 error:
1126 	DBF_EVENT(DBF_ERR, "%s",
1127 		  "Creation of the dasd debugfs interface failed");
1128 	dasd_statistics_removeroot();
1129 	return;
1130 }
1131 
1132 #else
1133 #define dasd_profile_start(block, cqr, req) do {} while (0)
1134 #define dasd_profile_end(block, cqr, req) do {} while (0)
1135 
1136 static void dasd_statistics_createroot(void)
1137 {
1138 	return;
1139 }
1140 
1141 static void dasd_statistics_removeroot(void)
1142 {
1143 	return;
1144 }
1145 
1146 int dasd_stats_generic_show(struct seq_file *m, void *v)
1147 {
1148 	seq_puts(m, "Statistics are not activated in this kernel\n");
1149 	return 0;
1150 }
1151 
1152 static void dasd_profile_init(struct dasd_profile *profile,
1153 			      struct dentry *base_dentry)
1154 {
1155 	return;
1156 }
1157 
1158 static void dasd_profile_exit(struct dasd_profile *profile)
1159 {
1160 	return;
1161 }
1162 
1163 int dasd_profile_on(struct dasd_profile *profile)
1164 {
1165 	return 0;
1166 }
1167 
1168 #endif				/* CONFIG_DASD_PROFILE */
1169 
1170 static int dasd_hosts_show(struct seq_file *m, void *v)
1171 {
1172 	struct dasd_device *device;
1173 	int rc = -EOPNOTSUPP;
1174 
1175 	device = m->private;
1176 	dasd_get_device(device);
1177 
1178 	if (device->discipline->hosts_print)
1179 		rc = device->discipline->hosts_print(device, m);
1180 
1181 	dasd_put_device(device);
1182 	return rc;
1183 }
1184 
1185 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1186 
1187 static void dasd_hosts_exit(struct dasd_device *device)
1188 {
1189 	debugfs_remove(device->hosts_dentry);
1190 	device->hosts_dentry = NULL;
1191 }
1192 
1193 static void dasd_hosts_init(struct dentry *base_dentry,
1194 			    struct dasd_device *device)
1195 {
1196 	struct dentry *pde;
1197 	umode_t mode;
1198 
1199 	if (!base_dentry)
1200 		return;
1201 
1202 	mode = S_IRUSR | S_IFREG;
1203 	pde = debugfs_create_file("host_access_list", mode, base_dentry,
1204 				  device, &dasd_hosts_fops);
1205 	if (pde && !IS_ERR(pde))
1206 		device->hosts_dentry = pde;
1207 }
1208 
1209 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1210 					  struct dasd_device *device,
1211 					  struct dasd_ccw_req *cqr)
1212 {
1213 	unsigned long flags;
1214 	char *data, *chunk;
1215 	int size = 0;
1216 
1217 	if (cplength > 0)
1218 		size += cplength * sizeof(struct ccw1);
1219 	if (datasize > 0)
1220 		size += datasize;
1221 	if (!cqr)
1222 		size += (sizeof(*cqr) + 7L) & -8L;
1223 
1224 	spin_lock_irqsave(&device->mem_lock, flags);
1225 	data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1226 	spin_unlock_irqrestore(&device->mem_lock, flags);
1227 	if (!chunk)
1228 		return ERR_PTR(-ENOMEM);
1229 	if (!cqr) {
1230 		cqr = (void *) data;
1231 		data += (sizeof(*cqr) + 7L) & -8L;
1232 	}
1233 	memset(cqr, 0, sizeof(*cqr));
1234 	cqr->mem_chunk = chunk;
1235 	if (cplength > 0) {
1236 		cqr->cpaddr = data;
1237 		data += cplength * sizeof(struct ccw1);
1238 		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1239 	}
1240 	if (datasize > 0) {
1241 		cqr->data = data;
1242  		memset(cqr->data, 0, datasize);
1243 	}
1244 	cqr->magic = magic;
1245 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1246 	dasd_get_device(device);
1247 	return cqr;
1248 }
1249 EXPORT_SYMBOL(dasd_smalloc_request);
1250 
1251 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1252 					  int datasize,
1253 					  struct dasd_device *device)
1254 {
1255 	struct dasd_ccw_req *cqr;
1256 	unsigned long flags;
1257 	int size, cqr_size;
1258 	char *data;
1259 
1260 	cqr_size = (sizeof(*cqr) + 7L) & -8L;
1261 	size = cqr_size;
1262 	if (cplength > 0)
1263 		size += cplength * sizeof(struct ccw1);
1264 	if (datasize > 0)
1265 		size += datasize;
1266 
1267 	spin_lock_irqsave(&device->mem_lock, flags);
1268 	cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1269 	spin_unlock_irqrestore(&device->mem_lock, flags);
1270 	if (!cqr)
1271 		return ERR_PTR(-ENOMEM);
1272 	memset(cqr, 0, sizeof(*cqr));
1273 	data = (char *)cqr + cqr_size;
1274 	cqr->cpaddr = NULL;
1275 	if (cplength > 0) {
1276 		cqr->cpaddr = data;
1277 		data += cplength * sizeof(struct ccw1);
1278 		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1279 	}
1280 	cqr->data = NULL;
1281 	if (datasize > 0) {
1282 		cqr->data = data;
1283 		memset(cqr->data, 0, datasize);
1284 	}
1285 
1286 	cqr->magic = magic;
1287 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1288 	dasd_get_device(device);
1289 
1290 	return cqr;
1291 }
1292 EXPORT_SYMBOL(dasd_fmalloc_request);
1293 
1294 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1295 {
1296 	unsigned long flags;
1297 
1298 	spin_lock_irqsave(&device->mem_lock, flags);
1299 	dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1300 	spin_unlock_irqrestore(&device->mem_lock, flags);
1301 	dasd_put_device(device);
1302 }
1303 EXPORT_SYMBOL(dasd_sfree_request);
1304 
1305 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1306 {
1307 	unsigned long flags;
1308 
1309 	spin_lock_irqsave(&device->mem_lock, flags);
1310 	dasd_free_chunk(&device->ese_chunks, cqr);
1311 	spin_unlock_irqrestore(&device->mem_lock, flags);
1312 	dasd_put_device(device);
1313 }
1314 EXPORT_SYMBOL(dasd_ffree_request);
1315 
1316 /*
1317  * Check discipline magic in cqr.
1318  */
1319 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1320 {
1321 	struct dasd_device *device;
1322 
1323 	if (cqr == NULL)
1324 		return -EINVAL;
1325 	device = cqr->startdev;
1326 	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1327 		DBF_DEV_EVENT(DBF_WARNING, device,
1328 			    " dasd_ccw_req 0x%08x magic doesn't match"
1329 			    " discipline 0x%08x",
1330 			    cqr->magic,
1331 			    *(unsigned int *) device->discipline->name);
1332 		return -EINVAL;
1333 	}
1334 	return 0;
1335 }
1336 
1337 /*
1338  * Terminate the current i/o and set the request to clear_pending.
1339  * Timer keeps device runnig.
1340  * ccw_device_clear can fail if the i/o subsystem
1341  * is in a bad mood.
1342  */
1343 int dasd_term_IO(struct dasd_ccw_req *cqr)
1344 {
1345 	struct dasd_device *device;
1346 	int retries, rc;
1347 	char errorstring[ERRORLENGTH];
1348 
1349 	/* Check the cqr */
1350 	rc = dasd_check_cqr(cqr);
1351 	if (rc)
1352 		return rc;
1353 	retries = 0;
1354 	device = (struct dasd_device *) cqr->startdev;
1355 	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1356 		rc = ccw_device_clear(device->cdev, (long) cqr);
1357 		switch (rc) {
1358 		case 0:	/* termination successful */
1359 			cqr->status = DASD_CQR_CLEAR_PENDING;
1360 			cqr->stopclk = get_tod_clock();
1361 			cqr->starttime = 0;
1362 			DBF_DEV_EVENT(DBF_DEBUG, device,
1363 				      "terminate cqr %p successful",
1364 				      cqr);
1365 			break;
1366 		case -ENODEV:
1367 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1368 				      "device gone, retry");
1369 			break;
1370 		case -EINVAL:
1371 			/*
1372 			 * device not valid so no I/O could be running
1373 			 * handle CQR as termination successful
1374 			 */
1375 			cqr->status = DASD_CQR_CLEARED;
1376 			cqr->stopclk = get_tod_clock();
1377 			cqr->starttime = 0;
1378 			/* no retries for invalid devices */
1379 			cqr->retries = -1;
1380 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1381 				      "EINVAL, handle as terminated");
1382 			/* fake rc to success */
1383 			rc = 0;
1384 			break;
1385 		default:
1386 			/* internal error 10 - unknown rc*/
1387 			snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1388 			dev_err(&device->cdev->dev, "An error occurred in the "
1389 				"DASD device driver, reason=%s\n", errorstring);
1390 			BUG();
1391 			break;
1392 		}
1393 		retries++;
1394 	}
1395 	dasd_schedule_device_bh(device);
1396 	return rc;
1397 }
1398 EXPORT_SYMBOL(dasd_term_IO);
1399 
1400 /*
1401  * Start the i/o. This start_IO can fail if the channel is really busy.
1402  * In that case set up a timer to start the request later.
1403  */
1404 int dasd_start_IO(struct dasd_ccw_req *cqr)
1405 {
1406 	struct dasd_device *device;
1407 	int rc;
1408 	char errorstring[ERRORLENGTH];
1409 
1410 	/* Check the cqr */
1411 	rc = dasd_check_cqr(cqr);
1412 	if (rc) {
1413 		cqr->intrc = rc;
1414 		return rc;
1415 	}
1416 	device = (struct dasd_device *) cqr->startdev;
1417 	if (((cqr->block &&
1418 	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1419 	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1420 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1421 		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1422 			      "because of stolen lock", cqr);
1423 		cqr->status = DASD_CQR_ERROR;
1424 		cqr->intrc = -EPERM;
1425 		return -EPERM;
1426 	}
1427 	if (cqr->retries < 0) {
1428 		/* internal error 14 - start_IO run out of retries */
1429 		sprintf(errorstring, "14 %p", cqr);
1430 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1431 			"device driver, reason=%s\n", errorstring);
1432 		cqr->status = DASD_CQR_ERROR;
1433 		return -EIO;
1434 	}
1435 	cqr->startclk = get_tod_clock();
1436 	cqr->starttime = jiffies;
1437 	cqr->retries--;
1438 	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1439 		cqr->lpm &= dasd_path_get_opm(device);
1440 		if (!cqr->lpm)
1441 			cqr->lpm = dasd_path_get_opm(device);
1442 	}
1443 	if (cqr->cpmode == 1) {
1444 		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1445 					 (long) cqr, cqr->lpm);
1446 	} else {
1447 		rc = ccw_device_start(device->cdev, cqr->cpaddr,
1448 				      (long) cqr, cqr->lpm, 0);
1449 	}
1450 	switch (rc) {
1451 	case 0:
1452 		cqr->status = DASD_CQR_IN_IO;
1453 		break;
1454 	case -EBUSY:
1455 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1456 			      "start_IO: device busy, retry later");
1457 		break;
1458 	case -EACCES:
1459 		/* -EACCES indicates that the request used only a subset of the
1460 		 * available paths and all these paths are gone. If the lpm of
1461 		 * this request was only a subset of the opm (e.g. the ppm) then
1462 		 * we just do a retry with all available paths.
1463 		 * If we already use the full opm, something is amiss, and we
1464 		 * need a full path verification.
1465 		 */
1466 		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1467 			DBF_DEV_EVENT(DBF_WARNING, device,
1468 				      "start_IO: selected paths gone (%x)",
1469 				      cqr->lpm);
1470 		} else if (cqr->lpm != dasd_path_get_opm(device)) {
1471 			cqr->lpm = dasd_path_get_opm(device);
1472 			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1473 				      "start_IO: selected paths gone,"
1474 				      " retry on all paths");
1475 		} else {
1476 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1477 				      "start_IO: all paths in opm gone,"
1478 				      " do path verification");
1479 			dasd_generic_last_path_gone(device);
1480 			dasd_path_no_path(device);
1481 			dasd_path_set_tbvpm(device,
1482 					  ccw_device_get_path_mask(
1483 						  device->cdev));
1484 		}
1485 		break;
1486 	case -ENODEV:
1487 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1488 			      "start_IO: -ENODEV device gone, retry");
1489 		break;
1490 	case -EIO:
1491 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1492 			      "start_IO: -EIO device gone, retry");
1493 		break;
1494 	case -EINVAL:
1495 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1496 			      "start_IO: -EINVAL device currently "
1497 			      "not accessible");
1498 		break;
1499 	default:
1500 		/* internal error 11 - unknown rc */
1501 		snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1502 		dev_err(&device->cdev->dev,
1503 			"An error occurred in the DASD device driver, "
1504 			"reason=%s\n", errorstring);
1505 		BUG();
1506 		break;
1507 	}
1508 	cqr->intrc = rc;
1509 	return rc;
1510 }
1511 EXPORT_SYMBOL(dasd_start_IO);
1512 
1513 /*
1514  * Timeout function for dasd devices. This is used for different purposes
1515  *  1) missing interrupt handler for normal operation
1516  *  2) delayed start of request where start_IO failed with -EBUSY
1517  *  3) timeout for missing state change interrupts
1518  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1519  * DASD_CQR_QUEUED for 2) and 3).
1520  */
1521 static void dasd_device_timeout(struct timer_list *t)
1522 {
1523 	unsigned long flags;
1524 	struct dasd_device *device;
1525 
1526 	device = from_timer(device, t, timer);
1527 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1528 	/* re-activate request queue */
1529 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1530 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1531 	dasd_schedule_device_bh(device);
1532 }
1533 
1534 /*
1535  * Setup timeout for a device in jiffies.
1536  */
1537 void dasd_device_set_timer(struct dasd_device *device, int expires)
1538 {
1539 	if (expires == 0)
1540 		del_timer(&device->timer);
1541 	else
1542 		mod_timer(&device->timer, jiffies + expires);
1543 }
1544 EXPORT_SYMBOL(dasd_device_set_timer);
1545 
1546 /*
1547  * Clear timeout for a device.
1548  */
1549 void dasd_device_clear_timer(struct dasd_device *device)
1550 {
1551 	del_timer(&device->timer);
1552 }
1553 EXPORT_SYMBOL(dasd_device_clear_timer);
1554 
1555 static void dasd_handle_killed_request(struct ccw_device *cdev,
1556 				       unsigned long intparm)
1557 {
1558 	struct dasd_ccw_req *cqr;
1559 	struct dasd_device *device;
1560 
1561 	if (!intparm)
1562 		return;
1563 	cqr = (struct dasd_ccw_req *) intparm;
1564 	if (cqr->status != DASD_CQR_IN_IO) {
1565 		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1566 				"invalid status in handle_killed_request: "
1567 				"%02x", cqr->status);
1568 		return;
1569 	}
1570 
1571 	device = dasd_device_from_cdev_locked(cdev);
1572 	if (IS_ERR(device)) {
1573 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1574 				"unable to get device from cdev");
1575 		return;
1576 	}
1577 
1578 	if (!cqr->startdev ||
1579 	    device != cqr->startdev ||
1580 	    strncmp(cqr->startdev->discipline->ebcname,
1581 		    (char *) &cqr->magic, 4)) {
1582 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1583 				"invalid device in request");
1584 		dasd_put_device(device);
1585 		return;
1586 	}
1587 
1588 	/* Schedule request to be retried. */
1589 	cqr->status = DASD_CQR_QUEUED;
1590 
1591 	dasd_device_clear_timer(device);
1592 	dasd_schedule_device_bh(device);
1593 	dasd_put_device(device);
1594 }
1595 
1596 void dasd_generic_handle_state_change(struct dasd_device *device)
1597 {
1598 	/* First of all start sense subsystem status request. */
1599 	dasd_eer_snss(device);
1600 
1601 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1602 	dasd_schedule_device_bh(device);
1603 	if (device->block) {
1604 		dasd_schedule_block_bh(device->block);
1605 		if (device->block->request_queue)
1606 			blk_mq_run_hw_queues(device->block->request_queue,
1607 					     true);
1608 	}
1609 }
1610 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1611 
1612 static int dasd_check_hpf_error(struct irb *irb)
1613 {
1614 	return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1615 	    (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1616 	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1617 }
1618 
1619 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1620 {
1621 	struct dasd_device *device = NULL;
1622 	u8 *sense = NULL;
1623 
1624 	if (!block)
1625 		return 0;
1626 	device = block->base;
1627 	if (!device || !device->discipline->is_ese)
1628 		return 0;
1629 	if (!device->discipline->is_ese(device))
1630 		return 0;
1631 
1632 	sense = dasd_get_sense(irb);
1633 	if (!sense)
1634 		return 0;
1635 
1636 	return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1637 		!!(sense[1] & SNS1_FILE_PROTECTED) ||
1638 		scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1639 }
1640 
1641 static int dasd_ese_oos_cond(u8 *sense)
1642 {
1643 	return sense[0] & SNS0_EQUIPMENT_CHECK &&
1644 		sense[1] & SNS1_PERM_ERR &&
1645 		sense[1] & SNS1_WRITE_INHIBITED &&
1646 		sense[25] == 0x01;
1647 }
1648 
1649 /*
1650  * Interrupt handler for "normal" ssch-io based dasd devices.
1651  */
1652 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1653 		      struct irb *irb)
1654 {
1655 	struct dasd_ccw_req *cqr, *next, *fcqr;
1656 	struct dasd_device *device;
1657 	unsigned long now;
1658 	int nrf_suppressed = 0;
1659 	int fp_suppressed = 0;
1660 	u8 *sense = NULL;
1661 	int expires;
1662 
1663 	cqr = (struct dasd_ccw_req *) intparm;
1664 	if (IS_ERR(irb)) {
1665 		switch (PTR_ERR(irb)) {
1666 		case -EIO:
1667 			if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1668 				device = cqr->startdev;
1669 				cqr->status = DASD_CQR_CLEARED;
1670 				dasd_device_clear_timer(device);
1671 				wake_up(&dasd_flush_wq);
1672 				dasd_schedule_device_bh(device);
1673 				return;
1674 			}
1675 			break;
1676 		case -ETIMEDOUT:
1677 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1678 					"request timed out\n", __func__);
1679 			break;
1680 		default:
1681 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1682 					"unknown error %ld\n", __func__,
1683 					PTR_ERR(irb));
1684 		}
1685 		dasd_handle_killed_request(cdev, intparm);
1686 		return;
1687 	}
1688 
1689 	now = get_tod_clock();
1690 	/* check for conditions that should be handled immediately */
1691 	if (!cqr ||
1692 	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1693 	      scsw_cstat(&irb->scsw) == 0)) {
1694 		if (cqr)
1695 			memcpy(&cqr->irb, irb, sizeof(*irb));
1696 		device = dasd_device_from_cdev_locked(cdev);
1697 		if (IS_ERR(device))
1698 			return;
1699 		/* ignore unsolicited interrupts for DIAG discipline */
1700 		if (device->discipline == dasd_diag_discipline_pointer) {
1701 			dasd_put_device(device);
1702 			return;
1703 		}
1704 
1705 		/*
1706 		 * In some cases 'File Protected' or 'No Record Found' errors
1707 		 * might be expected and debug log messages for the
1708 		 * corresponding interrupts shouldn't be written then.
1709 		 * Check if either of the according suppress bits is set.
1710 		 */
1711 		sense = dasd_get_sense(irb);
1712 		if (sense) {
1713 			fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1714 				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1715 			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1716 				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1717 
1718 			/*
1719 			 * Extent pool probably out-of-space.
1720 			 * Stop device and check exhaust level.
1721 			 */
1722 			if (dasd_ese_oos_cond(sense)) {
1723 				dasd_generic_space_exhaust(device, cqr);
1724 				device->discipline->ext_pool_exhaust(device, cqr);
1725 				dasd_put_device(device);
1726 				return;
1727 			}
1728 		}
1729 		if (!(fp_suppressed || nrf_suppressed))
1730 			device->discipline->dump_sense_dbf(device, irb, "int");
1731 
1732 		if (device->features & DASD_FEATURE_ERPLOG)
1733 			device->discipline->dump_sense(device, cqr, irb);
1734 		device->discipline->check_for_device_change(device, cqr, irb);
1735 		dasd_put_device(device);
1736 	}
1737 
1738 	/* check for for attention message */
1739 	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1740 		device = dasd_device_from_cdev_locked(cdev);
1741 		if (!IS_ERR(device)) {
1742 			device->discipline->check_attention(device,
1743 							    irb->esw.esw1.lpum);
1744 			dasd_put_device(device);
1745 		}
1746 	}
1747 
1748 	if (!cqr)
1749 		return;
1750 
1751 	device = (struct dasd_device *) cqr->startdev;
1752 	if (!device ||
1753 	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1754 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1755 				"invalid device in request");
1756 		return;
1757 	}
1758 
1759 	if (dasd_ese_needs_format(cqr->block, irb)) {
1760 		if (rq_data_dir((struct request *)cqr->callback_data) == READ) {
1761 			device->discipline->ese_read(cqr, irb);
1762 			cqr->status = DASD_CQR_SUCCESS;
1763 			cqr->stopclk = now;
1764 			dasd_device_clear_timer(device);
1765 			dasd_schedule_device_bh(device);
1766 			return;
1767 		}
1768 		fcqr = device->discipline->ese_format(device, cqr, irb);
1769 		if (IS_ERR(fcqr)) {
1770 			if (PTR_ERR(fcqr) == -EINVAL) {
1771 				cqr->status = DASD_CQR_ERROR;
1772 				return;
1773 			}
1774 			/*
1775 			 * If we can't format now, let the request go
1776 			 * one extra round. Maybe we can format later.
1777 			 */
1778 			cqr->status = DASD_CQR_QUEUED;
1779 			dasd_schedule_device_bh(device);
1780 			return;
1781 		} else {
1782 			fcqr->status = DASD_CQR_QUEUED;
1783 			cqr->status = DASD_CQR_QUEUED;
1784 			list_add(&fcqr->devlist, &device->ccw_queue);
1785 			dasd_schedule_device_bh(device);
1786 			return;
1787 		}
1788 	}
1789 
1790 	/* Check for clear pending */
1791 	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1792 	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1793 		cqr->status = DASD_CQR_CLEARED;
1794 		dasd_device_clear_timer(device);
1795 		wake_up(&dasd_flush_wq);
1796 		dasd_schedule_device_bh(device);
1797 		return;
1798 	}
1799 
1800 	/* check status - the request might have been killed by dyn detach */
1801 	if (cqr->status != DASD_CQR_IN_IO) {
1802 		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1803 			      "status %02x", dev_name(&cdev->dev), cqr->status);
1804 		return;
1805 	}
1806 
1807 	next = NULL;
1808 	expires = 0;
1809 	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1810 	    scsw_cstat(&irb->scsw) == 0) {
1811 		/* request was completed successfully */
1812 		cqr->status = DASD_CQR_SUCCESS;
1813 		cqr->stopclk = now;
1814 		/* Start first request on queue if possible -> fast_io. */
1815 		if (cqr->devlist.next != &device->ccw_queue) {
1816 			next = list_entry(cqr->devlist.next,
1817 					  struct dasd_ccw_req, devlist);
1818 		}
1819 	} else {  /* error */
1820 		/* check for HPF error
1821 		 * call discipline function to requeue all requests
1822 		 * and disable HPF accordingly
1823 		 */
1824 		if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1825 		    device->discipline->handle_hpf_error)
1826 			device->discipline->handle_hpf_error(device, irb);
1827 		/*
1828 		 * If we don't want complex ERP for this request, then just
1829 		 * reset this and retry it in the fastpath
1830 		 */
1831 		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1832 		    cqr->retries > 0) {
1833 			if (cqr->lpm == dasd_path_get_opm(device))
1834 				DBF_DEV_EVENT(DBF_DEBUG, device,
1835 					      "default ERP in fastpath "
1836 					      "(%i retries left)",
1837 					      cqr->retries);
1838 			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1839 				cqr->lpm = dasd_path_get_opm(device);
1840 			cqr->status = DASD_CQR_QUEUED;
1841 			next = cqr;
1842 		} else
1843 			cqr->status = DASD_CQR_ERROR;
1844 	}
1845 	if (next && (next->status == DASD_CQR_QUEUED) &&
1846 	    (!device->stopped)) {
1847 		if (device->discipline->start_IO(next) == 0)
1848 			expires = next->expires;
1849 	}
1850 	if (expires != 0)
1851 		dasd_device_set_timer(device, expires);
1852 	else
1853 		dasd_device_clear_timer(device);
1854 	dasd_schedule_device_bh(device);
1855 }
1856 EXPORT_SYMBOL(dasd_int_handler);
1857 
1858 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1859 {
1860 	struct dasd_device *device;
1861 
1862 	device = dasd_device_from_cdev_locked(cdev);
1863 
1864 	if (IS_ERR(device))
1865 		goto out;
1866 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1867 	   device->state != device->target ||
1868 	   !device->discipline->check_for_device_change){
1869 		dasd_put_device(device);
1870 		goto out;
1871 	}
1872 	if (device->discipline->dump_sense_dbf)
1873 		device->discipline->dump_sense_dbf(device, irb, "uc");
1874 	device->discipline->check_for_device_change(device, NULL, irb);
1875 	dasd_put_device(device);
1876 out:
1877 	return UC_TODO_RETRY;
1878 }
1879 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1880 
1881 /*
1882  * If we have an error on a dasd_block layer request then we cancel
1883  * and return all further requests from the same dasd_block as well.
1884  */
1885 static void __dasd_device_recovery(struct dasd_device *device,
1886 				   struct dasd_ccw_req *ref_cqr)
1887 {
1888 	struct list_head *l, *n;
1889 	struct dasd_ccw_req *cqr;
1890 
1891 	/*
1892 	 * only requeue request that came from the dasd_block layer
1893 	 */
1894 	if (!ref_cqr->block)
1895 		return;
1896 
1897 	list_for_each_safe(l, n, &device->ccw_queue) {
1898 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1899 		if (cqr->status == DASD_CQR_QUEUED &&
1900 		    ref_cqr->block == cqr->block) {
1901 			cqr->status = DASD_CQR_CLEARED;
1902 		}
1903 	}
1904 };
1905 
1906 /*
1907  * Remove those ccw requests from the queue that need to be returned
1908  * to the upper layer.
1909  */
1910 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1911 					    struct list_head *final_queue)
1912 {
1913 	struct list_head *l, *n;
1914 	struct dasd_ccw_req *cqr;
1915 
1916 	/* Process request with final status. */
1917 	list_for_each_safe(l, n, &device->ccw_queue) {
1918 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1919 
1920 		/* Skip any non-final request. */
1921 		if (cqr->status == DASD_CQR_QUEUED ||
1922 		    cqr->status == DASD_CQR_IN_IO ||
1923 		    cqr->status == DASD_CQR_CLEAR_PENDING)
1924 			continue;
1925 		if (cqr->status == DASD_CQR_ERROR) {
1926 			__dasd_device_recovery(device, cqr);
1927 		}
1928 		/* Rechain finished requests to final queue */
1929 		list_move_tail(&cqr->devlist, final_queue);
1930 	}
1931 }
1932 
1933 static void __dasd_process_cqr(struct dasd_device *device,
1934 			       struct dasd_ccw_req *cqr)
1935 {
1936 	char errorstring[ERRORLENGTH];
1937 
1938 	switch (cqr->status) {
1939 	case DASD_CQR_SUCCESS:
1940 		cqr->status = DASD_CQR_DONE;
1941 		break;
1942 	case DASD_CQR_ERROR:
1943 		cqr->status = DASD_CQR_NEED_ERP;
1944 		break;
1945 	case DASD_CQR_CLEARED:
1946 		cqr->status = DASD_CQR_TERMINATED;
1947 		break;
1948 	default:
1949 		/* internal error 12 - wrong cqr status*/
1950 		snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1951 		dev_err(&device->cdev->dev,
1952 			"An error occurred in the DASD device driver, "
1953 			"reason=%s\n", errorstring);
1954 		BUG();
1955 	}
1956 	if (cqr->callback)
1957 		cqr->callback(cqr, cqr->callback_data);
1958 }
1959 
1960 /*
1961  * the cqrs from the final queue are returned to the upper layer
1962  * by setting a dasd_block state and calling the callback function
1963  */
1964 static void __dasd_device_process_final_queue(struct dasd_device *device,
1965 					      struct list_head *final_queue)
1966 {
1967 	struct list_head *l, *n;
1968 	struct dasd_ccw_req *cqr;
1969 	struct dasd_block *block;
1970 
1971 	list_for_each_safe(l, n, final_queue) {
1972 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1973 		list_del_init(&cqr->devlist);
1974 		block = cqr->block;
1975 		if (!block) {
1976 			__dasd_process_cqr(device, cqr);
1977 		} else {
1978 			spin_lock_bh(&block->queue_lock);
1979 			__dasd_process_cqr(device, cqr);
1980 			spin_unlock_bh(&block->queue_lock);
1981 		}
1982 	}
1983 }
1984 
1985 /*
1986  * Take a look at the first request on the ccw queue and check
1987  * if it reached its expire time. If so, terminate the IO.
1988  */
1989 static void __dasd_device_check_expire(struct dasd_device *device)
1990 {
1991 	struct dasd_ccw_req *cqr;
1992 
1993 	if (list_empty(&device->ccw_queue))
1994 		return;
1995 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1996 	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1997 	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1998 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1999 			/*
2000 			 * IO in safe offline processing should not
2001 			 * run out of retries
2002 			 */
2003 			cqr->retries++;
2004 		}
2005 		if (device->discipline->term_IO(cqr) != 0) {
2006 			/* Hmpf, try again in 5 sec */
2007 			dev_err(&device->cdev->dev,
2008 				"cqr %p timed out (%lus) but cannot be "
2009 				"ended, retrying in 5 s\n",
2010 				cqr, (cqr->expires/HZ));
2011 			cqr->expires += 5*HZ;
2012 			dasd_device_set_timer(device, 5*HZ);
2013 		} else {
2014 			dev_err(&device->cdev->dev,
2015 				"cqr %p timed out (%lus), %i retries "
2016 				"remaining\n", cqr, (cqr->expires/HZ),
2017 				cqr->retries);
2018 		}
2019 	}
2020 }
2021 
2022 /*
2023  * return 1 when device is not eligible for IO
2024  */
2025 static int __dasd_device_is_unusable(struct dasd_device *device,
2026 				     struct dasd_ccw_req *cqr)
2027 {
2028 	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
2029 
2030 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2031 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2032 		/*
2033 		 * dasd is being set offline
2034 		 * but it is no safe offline where we have to allow I/O
2035 		 */
2036 		return 1;
2037 	}
2038 	if (device->stopped) {
2039 		if (device->stopped & mask) {
2040 			/* stopped and CQR will not change that. */
2041 			return 1;
2042 		}
2043 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2044 			/* CQR is not able to change device to
2045 			 * operational. */
2046 			return 1;
2047 		}
2048 		/* CQR required to get device operational. */
2049 	}
2050 	return 0;
2051 }
2052 
2053 /*
2054  * Take a look at the first request on the ccw queue and check
2055  * if it needs to be started.
2056  */
2057 static void __dasd_device_start_head(struct dasd_device *device)
2058 {
2059 	struct dasd_ccw_req *cqr;
2060 	int rc;
2061 
2062 	if (list_empty(&device->ccw_queue))
2063 		return;
2064 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2065 	if (cqr->status != DASD_CQR_QUEUED)
2066 		return;
2067 	/* if device is not usable return request to upper layer */
2068 	if (__dasd_device_is_unusable(device, cqr)) {
2069 		cqr->intrc = -EAGAIN;
2070 		cqr->status = DASD_CQR_CLEARED;
2071 		dasd_schedule_device_bh(device);
2072 		return;
2073 	}
2074 
2075 	rc = device->discipline->start_IO(cqr);
2076 	if (rc == 0)
2077 		dasd_device_set_timer(device, cqr->expires);
2078 	else if (rc == -EACCES) {
2079 		dasd_schedule_device_bh(device);
2080 	} else
2081 		/* Hmpf, try again in 1/2 sec */
2082 		dasd_device_set_timer(device, 50);
2083 }
2084 
2085 static void __dasd_device_check_path_events(struct dasd_device *device)
2086 {
2087 	int rc;
2088 
2089 	if (!dasd_path_get_tbvpm(device))
2090 		return;
2091 
2092 	if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
2093 		return;
2094 	rc = device->discipline->verify_path(device,
2095 					     dasd_path_get_tbvpm(device));
2096 	if (rc)
2097 		dasd_device_set_timer(device, 50);
2098 	else
2099 		dasd_path_clear_all_verify(device);
2100 };
2101 
2102 /*
2103  * Go through all request on the dasd_device request queue,
2104  * terminate them on the cdev if necessary, and return them to the
2105  * submitting layer via callback.
2106  * Note:
2107  * Make sure that all 'submitting layers' still exist when
2108  * this function is called!. In other words, when 'device' is a base
2109  * device then all block layer requests must have been removed before
2110  * via dasd_flush_block_queue.
2111  */
2112 int dasd_flush_device_queue(struct dasd_device *device)
2113 {
2114 	struct dasd_ccw_req *cqr, *n;
2115 	int rc;
2116 	struct list_head flush_queue;
2117 
2118 	INIT_LIST_HEAD(&flush_queue);
2119 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2120 	rc = 0;
2121 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2122 		/* Check status and move request to flush_queue */
2123 		switch (cqr->status) {
2124 		case DASD_CQR_IN_IO:
2125 			rc = device->discipline->term_IO(cqr);
2126 			if (rc) {
2127 				/* unable to terminate requeust */
2128 				dev_err(&device->cdev->dev,
2129 					"Flushing the DASD request queue "
2130 					"failed for request %p\n", cqr);
2131 				/* stop flush processing */
2132 				goto finished;
2133 			}
2134 			break;
2135 		case DASD_CQR_QUEUED:
2136 			cqr->stopclk = get_tod_clock();
2137 			cqr->status = DASD_CQR_CLEARED;
2138 			break;
2139 		default: /* no need to modify the others */
2140 			break;
2141 		}
2142 		list_move_tail(&cqr->devlist, &flush_queue);
2143 	}
2144 finished:
2145 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2146 	/*
2147 	 * After this point all requests must be in state CLEAR_PENDING,
2148 	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2149 	 * one of the others.
2150 	 */
2151 	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2152 		wait_event(dasd_flush_wq,
2153 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
2154 	/*
2155 	 * Now set each request back to TERMINATED, DONE or NEED_ERP
2156 	 * and call the callback function of flushed requests
2157 	 */
2158 	__dasd_device_process_final_queue(device, &flush_queue);
2159 	return rc;
2160 }
2161 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2162 
2163 /*
2164  * Acquire the device lock and process queues for the device.
2165  */
2166 static void dasd_device_tasklet(unsigned long data)
2167 {
2168 	struct dasd_device *device = (struct dasd_device *) data;
2169 	struct list_head final_queue;
2170 
2171 	atomic_set (&device->tasklet_scheduled, 0);
2172 	INIT_LIST_HEAD(&final_queue);
2173 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2174 	/* Check expire time of first request on the ccw queue. */
2175 	__dasd_device_check_expire(device);
2176 	/* find final requests on ccw queue */
2177 	__dasd_device_process_ccw_queue(device, &final_queue);
2178 	__dasd_device_check_path_events(device);
2179 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2180 	/* Now call the callback function of requests with final status */
2181 	__dasd_device_process_final_queue(device, &final_queue);
2182 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2183 	/* Now check if the head of the ccw queue needs to be started. */
2184 	__dasd_device_start_head(device);
2185 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2186 	if (waitqueue_active(&shutdown_waitq))
2187 		wake_up(&shutdown_waitq);
2188 	dasd_put_device(device);
2189 }
2190 
2191 /*
2192  * Schedules a call to dasd_tasklet over the device tasklet.
2193  */
2194 void dasd_schedule_device_bh(struct dasd_device *device)
2195 {
2196 	/* Protect against rescheduling. */
2197 	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2198 		return;
2199 	dasd_get_device(device);
2200 	tasklet_hi_schedule(&device->tasklet);
2201 }
2202 EXPORT_SYMBOL(dasd_schedule_device_bh);
2203 
2204 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2205 {
2206 	device->stopped |= bits;
2207 }
2208 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2209 
2210 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2211 {
2212 	device->stopped &= ~bits;
2213 	if (!device->stopped)
2214 		wake_up(&generic_waitq);
2215 }
2216 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2217 
2218 /*
2219  * Queue a request to the head of the device ccw_queue.
2220  * Start the I/O if possible.
2221  */
2222 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2223 {
2224 	struct dasd_device *device;
2225 	unsigned long flags;
2226 
2227 	device = cqr->startdev;
2228 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2229 	cqr->status = DASD_CQR_QUEUED;
2230 	list_add(&cqr->devlist, &device->ccw_queue);
2231 	/* let the bh start the request to keep them in order */
2232 	dasd_schedule_device_bh(device);
2233 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2234 }
2235 EXPORT_SYMBOL(dasd_add_request_head);
2236 
2237 /*
2238  * Queue a request to the tail of the device ccw_queue.
2239  * Start the I/O if possible.
2240  */
2241 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2242 {
2243 	struct dasd_device *device;
2244 	unsigned long flags;
2245 
2246 	device = cqr->startdev;
2247 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2248 	cqr->status = DASD_CQR_QUEUED;
2249 	list_add_tail(&cqr->devlist, &device->ccw_queue);
2250 	/* let the bh start the request to keep them in order */
2251 	dasd_schedule_device_bh(device);
2252 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2253 }
2254 EXPORT_SYMBOL(dasd_add_request_tail);
2255 
2256 /*
2257  * Wakeup helper for the 'sleep_on' functions.
2258  */
2259 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2260 {
2261 	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2262 	cqr->callback_data = DASD_SLEEPON_END_TAG;
2263 	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2264 	wake_up(&generic_waitq);
2265 }
2266 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2267 
2268 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2269 {
2270 	struct dasd_device *device;
2271 	int rc;
2272 
2273 	device = cqr->startdev;
2274 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2275 	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2276 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2277 	return rc;
2278 }
2279 
2280 /*
2281  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2282  */
2283 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2284 {
2285 	struct dasd_device *device;
2286 	dasd_erp_fn_t erp_fn;
2287 
2288 	if (cqr->status == DASD_CQR_FILLED)
2289 		return 0;
2290 	device = cqr->startdev;
2291 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2292 		if (cqr->status == DASD_CQR_TERMINATED) {
2293 			device->discipline->handle_terminated_request(cqr);
2294 			return 1;
2295 		}
2296 		if (cqr->status == DASD_CQR_NEED_ERP) {
2297 			erp_fn = device->discipline->erp_action(cqr);
2298 			erp_fn(cqr);
2299 			return 1;
2300 		}
2301 		if (cqr->status == DASD_CQR_FAILED)
2302 			dasd_log_sense(cqr, &cqr->irb);
2303 		if (cqr->refers) {
2304 			__dasd_process_erp(device, cqr);
2305 			return 1;
2306 		}
2307 	}
2308 	return 0;
2309 }
2310 
2311 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2312 {
2313 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2314 		if (cqr->refers) /* erp is not done yet */
2315 			return 1;
2316 		return ((cqr->status != DASD_CQR_DONE) &&
2317 			(cqr->status != DASD_CQR_FAILED));
2318 	} else
2319 		return (cqr->status == DASD_CQR_FILLED);
2320 }
2321 
2322 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2323 {
2324 	struct dasd_device *device;
2325 	int rc;
2326 	struct list_head ccw_queue;
2327 	struct dasd_ccw_req *cqr;
2328 
2329 	INIT_LIST_HEAD(&ccw_queue);
2330 	maincqr->status = DASD_CQR_FILLED;
2331 	device = maincqr->startdev;
2332 	list_add(&maincqr->blocklist, &ccw_queue);
2333 	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2334 	     cqr = list_first_entry(&ccw_queue,
2335 				    struct dasd_ccw_req, blocklist)) {
2336 
2337 		if (__dasd_sleep_on_erp(cqr))
2338 			continue;
2339 		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2340 			continue;
2341 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2342 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2343 			cqr->status = DASD_CQR_FAILED;
2344 			cqr->intrc = -EPERM;
2345 			continue;
2346 		}
2347 		/* Non-temporary stop condition will trigger fail fast */
2348 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2349 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2350 		    (!dasd_eer_enabled(device))) {
2351 			cqr->status = DASD_CQR_FAILED;
2352 			cqr->intrc = -ENOLINK;
2353 			continue;
2354 		}
2355 		/*
2356 		 * Don't try to start requests if device is in
2357 		 * offline processing, it might wait forever
2358 		 */
2359 		if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2360 			cqr->status = DASD_CQR_FAILED;
2361 			cqr->intrc = -ENODEV;
2362 			continue;
2363 		}
2364 		/*
2365 		 * Don't try to start requests if device is stopped
2366 		 * except path verification requests
2367 		 */
2368 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2369 			if (interruptible) {
2370 				rc = wait_event_interruptible(
2371 					generic_waitq, !(device->stopped));
2372 				if (rc == -ERESTARTSYS) {
2373 					cqr->status = DASD_CQR_FAILED;
2374 					maincqr->intrc = rc;
2375 					continue;
2376 				}
2377 			} else
2378 				wait_event(generic_waitq, !(device->stopped));
2379 		}
2380 		if (!cqr->callback)
2381 			cqr->callback = dasd_wakeup_cb;
2382 
2383 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2384 		dasd_add_request_tail(cqr);
2385 		if (interruptible) {
2386 			rc = wait_event_interruptible(
2387 				generic_waitq, _wait_for_wakeup(cqr));
2388 			if (rc == -ERESTARTSYS) {
2389 				dasd_cancel_req(cqr);
2390 				/* wait (non-interruptible) for final status */
2391 				wait_event(generic_waitq,
2392 					   _wait_for_wakeup(cqr));
2393 				cqr->status = DASD_CQR_FAILED;
2394 				maincqr->intrc = rc;
2395 				continue;
2396 			}
2397 		} else
2398 			wait_event(generic_waitq, _wait_for_wakeup(cqr));
2399 	}
2400 
2401 	maincqr->endclk = get_tod_clock();
2402 	if ((maincqr->status != DASD_CQR_DONE) &&
2403 	    (maincqr->intrc != -ERESTARTSYS))
2404 		dasd_log_sense(maincqr, &maincqr->irb);
2405 	if (maincqr->status == DASD_CQR_DONE)
2406 		rc = 0;
2407 	else if (maincqr->intrc)
2408 		rc = maincqr->intrc;
2409 	else
2410 		rc = -EIO;
2411 	return rc;
2412 }
2413 
2414 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2415 {
2416 	struct dasd_ccw_req *cqr;
2417 
2418 	list_for_each_entry(cqr, ccw_queue, blocklist) {
2419 		if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2420 			return 0;
2421 	}
2422 
2423 	return 1;
2424 }
2425 
2426 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2427 {
2428 	struct dasd_device *device;
2429 	struct dasd_ccw_req *cqr, *n;
2430 	u8 *sense = NULL;
2431 	int rc;
2432 
2433 retry:
2434 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2435 		device = cqr->startdev;
2436 		if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2437 			continue;
2438 
2439 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2440 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2441 			cqr->status = DASD_CQR_FAILED;
2442 			cqr->intrc = -EPERM;
2443 			continue;
2444 		}
2445 		/*Non-temporary stop condition will trigger fail fast*/
2446 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2447 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2448 		    !dasd_eer_enabled(device)) {
2449 			cqr->status = DASD_CQR_FAILED;
2450 			cqr->intrc = -EAGAIN;
2451 			continue;
2452 		}
2453 
2454 		/*Don't try to start requests if device is stopped*/
2455 		if (interruptible) {
2456 			rc = wait_event_interruptible(
2457 				generic_waitq, !device->stopped);
2458 			if (rc == -ERESTARTSYS) {
2459 				cqr->status = DASD_CQR_FAILED;
2460 				cqr->intrc = rc;
2461 				continue;
2462 			}
2463 		} else
2464 			wait_event(generic_waitq, !(device->stopped));
2465 
2466 		if (!cqr->callback)
2467 			cqr->callback = dasd_wakeup_cb;
2468 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2469 		dasd_add_request_tail(cqr);
2470 	}
2471 
2472 	wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2473 
2474 	rc = 0;
2475 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2476 		/*
2477 		 * In some cases the 'File Protected' or 'Incorrect Length'
2478 		 * error might be expected and error recovery would be
2479 		 * unnecessary in these cases.	Check if the according suppress
2480 		 * bit is set.
2481 		 */
2482 		sense = dasd_get_sense(&cqr->irb);
2483 		if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2484 		    test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2485 			continue;
2486 		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2487 		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2488 			continue;
2489 
2490 		/*
2491 		 * for alias devices simplify error recovery and
2492 		 * return to upper layer
2493 		 * do not skip ERP requests
2494 		 */
2495 		if (cqr->startdev != cqr->basedev && !cqr->refers &&
2496 		    (cqr->status == DASD_CQR_TERMINATED ||
2497 		     cqr->status == DASD_CQR_NEED_ERP))
2498 			return -EAGAIN;
2499 
2500 		/* normal recovery for basedev IO */
2501 		if (__dasd_sleep_on_erp(cqr))
2502 			/* handle erp first */
2503 			goto retry;
2504 	}
2505 
2506 	return 0;
2507 }
2508 
2509 /*
2510  * Queue a request to the tail of the device ccw_queue and wait for
2511  * it's completion.
2512  */
2513 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2514 {
2515 	return _dasd_sleep_on(cqr, 0);
2516 }
2517 EXPORT_SYMBOL(dasd_sleep_on);
2518 
2519 /*
2520  * Start requests from a ccw_queue and wait for their completion.
2521  */
2522 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2523 {
2524 	return _dasd_sleep_on_queue(ccw_queue, 0);
2525 }
2526 EXPORT_SYMBOL(dasd_sleep_on_queue);
2527 
2528 /*
2529  * Start requests from a ccw_queue and wait interruptible for their completion.
2530  */
2531 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2532 {
2533 	return _dasd_sleep_on_queue(ccw_queue, 1);
2534 }
2535 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2536 
2537 /*
2538  * Queue a request to the tail of the device ccw_queue and wait
2539  * interruptible for it's completion.
2540  */
2541 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2542 {
2543 	return _dasd_sleep_on(cqr, 1);
2544 }
2545 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2546 
2547 /*
2548  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2549  * for eckd devices) the currently running request has to be terminated
2550  * and be put back to status queued, before the special request is added
2551  * to the head of the queue. Then the special request is waited on normally.
2552  */
2553 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2554 {
2555 	struct dasd_ccw_req *cqr;
2556 	int rc;
2557 
2558 	if (list_empty(&device->ccw_queue))
2559 		return 0;
2560 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2561 	rc = device->discipline->term_IO(cqr);
2562 	if (!rc)
2563 		/*
2564 		 * CQR terminated because a more important request is pending.
2565 		 * Undo decreasing of retry counter because this is
2566 		 * not an error case.
2567 		 */
2568 		cqr->retries++;
2569 	return rc;
2570 }
2571 
2572 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2573 {
2574 	struct dasd_device *device;
2575 	int rc;
2576 
2577 	device = cqr->startdev;
2578 	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2579 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2580 		cqr->status = DASD_CQR_FAILED;
2581 		cqr->intrc = -EPERM;
2582 		return -EIO;
2583 	}
2584 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2585 	rc = _dasd_term_running_cqr(device);
2586 	if (rc) {
2587 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
2588 		return rc;
2589 	}
2590 	cqr->callback = dasd_wakeup_cb;
2591 	cqr->callback_data = DASD_SLEEPON_START_TAG;
2592 	cqr->status = DASD_CQR_QUEUED;
2593 	/*
2594 	 * add new request as second
2595 	 * first the terminated cqr needs to be finished
2596 	 */
2597 	list_add(&cqr->devlist, device->ccw_queue.next);
2598 
2599 	/* let the bh start the request to keep them in order */
2600 	dasd_schedule_device_bh(device);
2601 
2602 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2603 
2604 	wait_event(generic_waitq, _wait_for_wakeup(cqr));
2605 
2606 	if (cqr->status == DASD_CQR_DONE)
2607 		rc = 0;
2608 	else if (cqr->intrc)
2609 		rc = cqr->intrc;
2610 	else
2611 		rc = -EIO;
2612 
2613 	/* kick tasklets */
2614 	dasd_schedule_device_bh(device);
2615 	if (device->block)
2616 		dasd_schedule_block_bh(device->block);
2617 
2618 	return rc;
2619 }
2620 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2621 
2622 /*
2623  * Cancels a request that was started with dasd_sleep_on_req.
2624  * This is useful to timeout requests. The request will be
2625  * terminated if it is currently in i/o.
2626  * Returns 0 if request termination was successful
2627  *	   negative error code if termination failed
2628  * Cancellation of a request is an asynchronous operation! The calling
2629  * function has to wait until the request is properly returned via callback.
2630  */
2631 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2632 {
2633 	struct dasd_device *device = cqr->startdev;
2634 	int rc = 0;
2635 
2636 	switch (cqr->status) {
2637 	case DASD_CQR_QUEUED:
2638 		/* request was not started - just set to cleared */
2639 		cqr->status = DASD_CQR_CLEARED;
2640 		break;
2641 	case DASD_CQR_IN_IO:
2642 		/* request in IO - terminate IO and release again */
2643 		rc = device->discipline->term_IO(cqr);
2644 		if (rc) {
2645 			dev_err(&device->cdev->dev,
2646 				"Cancelling request %p failed with rc=%d\n",
2647 				cqr, rc);
2648 		} else {
2649 			cqr->stopclk = get_tod_clock();
2650 		}
2651 		break;
2652 	default: /* already finished or clear pending - do nothing */
2653 		break;
2654 	}
2655 	dasd_schedule_device_bh(device);
2656 	return rc;
2657 }
2658 
2659 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2660 {
2661 	struct dasd_device *device = cqr->startdev;
2662 	unsigned long flags;
2663 	int rc;
2664 
2665 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2666 	rc = __dasd_cancel_req(cqr);
2667 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2668 	return rc;
2669 }
2670 
2671 /*
2672  * SECTION: Operations of the dasd_block layer.
2673  */
2674 
2675 /*
2676  * Timeout function for dasd_block. This is used when the block layer
2677  * is waiting for something that may not come reliably, (e.g. a state
2678  * change interrupt)
2679  */
2680 static void dasd_block_timeout(struct timer_list *t)
2681 {
2682 	unsigned long flags;
2683 	struct dasd_block *block;
2684 
2685 	block = from_timer(block, t, timer);
2686 	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2687 	/* re-activate request queue */
2688 	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2689 	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2690 	dasd_schedule_block_bh(block);
2691 	blk_mq_run_hw_queues(block->request_queue, true);
2692 }
2693 
2694 /*
2695  * Setup timeout for a dasd_block in jiffies.
2696  */
2697 void dasd_block_set_timer(struct dasd_block *block, int expires)
2698 {
2699 	if (expires == 0)
2700 		del_timer(&block->timer);
2701 	else
2702 		mod_timer(&block->timer, jiffies + expires);
2703 }
2704 EXPORT_SYMBOL(dasd_block_set_timer);
2705 
2706 /*
2707  * Clear timeout for a dasd_block.
2708  */
2709 void dasd_block_clear_timer(struct dasd_block *block)
2710 {
2711 	del_timer(&block->timer);
2712 }
2713 EXPORT_SYMBOL(dasd_block_clear_timer);
2714 
2715 /*
2716  * Process finished error recovery ccw.
2717  */
2718 static void __dasd_process_erp(struct dasd_device *device,
2719 			       struct dasd_ccw_req *cqr)
2720 {
2721 	dasd_erp_fn_t erp_fn;
2722 
2723 	if (cqr->status == DASD_CQR_DONE)
2724 		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2725 	else
2726 		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2727 	erp_fn = device->discipline->erp_postaction(cqr);
2728 	erp_fn(cqr);
2729 }
2730 
2731 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2732 {
2733 	struct request *req;
2734 	blk_status_t error = BLK_STS_OK;
2735 	unsigned int proc_bytes;
2736 	int status;
2737 
2738 	req = (struct request *) cqr->callback_data;
2739 	dasd_profile_end(cqr->block, cqr, req);
2740 
2741 	proc_bytes = cqr->proc_bytes;
2742 	status = cqr->block->base->discipline->free_cp(cqr, req);
2743 	if (status < 0)
2744 		error = errno_to_blk_status(status);
2745 	else if (status == 0) {
2746 		switch (cqr->intrc) {
2747 		case -EPERM:
2748 			error = BLK_STS_NEXUS;
2749 			break;
2750 		case -ENOLINK:
2751 			error = BLK_STS_TRANSPORT;
2752 			break;
2753 		case -ETIMEDOUT:
2754 			error = BLK_STS_TIMEOUT;
2755 			break;
2756 		default:
2757 			error = BLK_STS_IOERR;
2758 			break;
2759 		}
2760 	}
2761 
2762 	/*
2763 	 * We need to take care for ETIMEDOUT errors here since the
2764 	 * complete callback does not get called in this case.
2765 	 * Take care of all errors here and avoid additional code to
2766 	 * transfer the error value to the complete callback.
2767 	 */
2768 	if (error) {
2769 		blk_mq_end_request(req, error);
2770 		blk_mq_run_hw_queues(req->q, true);
2771 	} else {
2772 		/*
2773 		 * Partial completed requests can happen with ESE devices.
2774 		 * During read we might have gotten a NRF error and have to
2775 		 * complete a request partially.
2776 		 */
2777 		if (proc_bytes) {
2778 			blk_update_request(req, BLK_STS_OK,
2779 					   blk_rq_bytes(req) - proc_bytes);
2780 			blk_mq_requeue_request(req, true);
2781 		} else if (likely(!blk_should_fake_timeout(req->q))) {
2782 			blk_mq_complete_request(req);
2783 		}
2784 	}
2785 }
2786 
2787 /*
2788  * Process ccw request queue.
2789  */
2790 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2791 					   struct list_head *final_queue)
2792 {
2793 	struct list_head *l, *n;
2794 	struct dasd_ccw_req *cqr;
2795 	dasd_erp_fn_t erp_fn;
2796 	unsigned long flags;
2797 	struct dasd_device *base = block->base;
2798 
2799 restart:
2800 	/* Process request with final status. */
2801 	list_for_each_safe(l, n, &block->ccw_queue) {
2802 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2803 		if (cqr->status != DASD_CQR_DONE &&
2804 		    cqr->status != DASD_CQR_FAILED &&
2805 		    cqr->status != DASD_CQR_NEED_ERP &&
2806 		    cqr->status != DASD_CQR_TERMINATED)
2807 			continue;
2808 
2809 		if (cqr->status == DASD_CQR_TERMINATED) {
2810 			base->discipline->handle_terminated_request(cqr);
2811 			goto restart;
2812 		}
2813 
2814 		/*  Process requests that may be recovered */
2815 		if (cqr->status == DASD_CQR_NEED_ERP) {
2816 			erp_fn = base->discipline->erp_action(cqr);
2817 			if (IS_ERR(erp_fn(cqr)))
2818 				continue;
2819 			goto restart;
2820 		}
2821 
2822 		/* log sense for fatal error */
2823 		if (cqr->status == DASD_CQR_FAILED) {
2824 			dasd_log_sense(cqr, &cqr->irb);
2825 		}
2826 
2827 		/* First of all call extended error reporting. */
2828 		if (dasd_eer_enabled(base) &&
2829 		    cqr->status == DASD_CQR_FAILED) {
2830 			dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2831 
2832 			/* restart request  */
2833 			cqr->status = DASD_CQR_FILLED;
2834 			cqr->retries = 255;
2835 			spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2836 			dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2837 			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2838 					       flags);
2839 			goto restart;
2840 		}
2841 
2842 		/* Process finished ERP request. */
2843 		if (cqr->refers) {
2844 			__dasd_process_erp(base, cqr);
2845 			goto restart;
2846 		}
2847 
2848 		/* Rechain finished requests to final queue */
2849 		cqr->endclk = get_tod_clock();
2850 		list_move_tail(&cqr->blocklist, final_queue);
2851 	}
2852 }
2853 
2854 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2855 {
2856 	dasd_schedule_block_bh(cqr->block);
2857 }
2858 
2859 static void __dasd_block_start_head(struct dasd_block *block)
2860 {
2861 	struct dasd_ccw_req *cqr;
2862 
2863 	if (list_empty(&block->ccw_queue))
2864 		return;
2865 	/* We allways begin with the first requests on the queue, as some
2866 	 * of previously started requests have to be enqueued on a
2867 	 * dasd_device again for error recovery.
2868 	 */
2869 	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2870 		if (cqr->status != DASD_CQR_FILLED)
2871 			continue;
2872 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2873 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2874 			cqr->status = DASD_CQR_FAILED;
2875 			cqr->intrc = -EPERM;
2876 			dasd_schedule_block_bh(block);
2877 			continue;
2878 		}
2879 		/* Non-temporary stop condition will trigger fail fast */
2880 		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2881 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2882 		    (!dasd_eer_enabled(block->base))) {
2883 			cqr->status = DASD_CQR_FAILED;
2884 			cqr->intrc = -ENOLINK;
2885 			dasd_schedule_block_bh(block);
2886 			continue;
2887 		}
2888 		/* Don't try to start requests if device is stopped */
2889 		if (block->base->stopped)
2890 			return;
2891 
2892 		/* just a fail safe check, should not happen */
2893 		if (!cqr->startdev)
2894 			cqr->startdev = block->base;
2895 
2896 		/* make sure that the requests we submit find their way back */
2897 		cqr->callback = dasd_return_cqr_cb;
2898 
2899 		dasd_add_request_tail(cqr);
2900 	}
2901 }
2902 
2903 /*
2904  * Central dasd_block layer routine. Takes requests from the generic
2905  * block layer request queue, creates ccw requests, enqueues them on
2906  * a dasd_device and processes ccw requests that have been returned.
2907  */
2908 static void dasd_block_tasklet(unsigned long data)
2909 {
2910 	struct dasd_block *block = (struct dasd_block *) data;
2911 	struct list_head final_queue;
2912 	struct list_head *l, *n;
2913 	struct dasd_ccw_req *cqr;
2914 	struct dasd_queue *dq;
2915 
2916 	atomic_set(&block->tasklet_scheduled, 0);
2917 	INIT_LIST_HEAD(&final_queue);
2918 	spin_lock_irq(&block->queue_lock);
2919 	/* Finish off requests on ccw queue */
2920 	__dasd_process_block_ccw_queue(block, &final_queue);
2921 	spin_unlock_irq(&block->queue_lock);
2922 
2923 	/* Now call the callback function of requests with final status */
2924 	list_for_each_safe(l, n, &final_queue) {
2925 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2926 		dq = cqr->dq;
2927 		spin_lock_irq(&dq->lock);
2928 		list_del_init(&cqr->blocklist);
2929 		__dasd_cleanup_cqr(cqr);
2930 		spin_unlock_irq(&dq->lock);
2931 	}
2932 
2933 	spin_lock_irq(&block->queue_lock);
2934 	/* Now check if the head of the ccw queue needs to be started. */
2935 	__dasd_block_start_head(block);
2936 	spin_unlock_irq(&block->queue_lock);
2937 
2938 	if (waitqueue_active(&shutdown_waitq))
2939 		wake_up(&shutdown_waitq);
2940 	dasd_put_device(block->base);
2941 }
2942 
2943 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2944 {
2945 	wake_up(&dasd_flush_wq);
2946 }
2947 
2948 /*
2949  * Requeue a request back to the block request queue
2950  * only works for block requests
2951  */
2952 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2953 {
2954 	struct dasd_block *block = cqr->block;
2955 	struct request *req;
2956 
2957 	if (!block)
2958 		return -EINVAL;
2959 	/*
2960 	 * If the request is an ERP request there is nothing to requeue.
2961 	 * This will be done with the remaining original request.
2962 	 */
2963 	if (cqr->refers)
2964 		return 0;
2965 	spin_lock_irq(&cqr->dq->lock);
2966 	req = (struct request *) cqr->callback_data;
2967 	blk_mq_requeue_request(req, false);
2968 	spin_unlock_irq(&cqr->dq->lock);
2969 
2970 	return 0;
2971 }
2972 
2973 /*
2974  * Go through all request on the dasd_block request queue, cancel them
2975  * on the respective dasd_device, and return them to the generic
2976  * block layer.
2977  */
2978 static int dasd_flush_block_queue(struct dasd_block *block)
2979 {
2980 	struct dasd_ccw_req *cqr, *n;
2981 	int rc, i;
2982 	struct list_head flush_queue;
2983 	unsigned long flags;
2984 
2985 	INIT_LIST_HEAD(&flush_queue);
2986 	spin_lock_bh(&block->queue_lock);
2987 	rc = 0;
2988 restart:
2989 	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2990 		/* if this request currently owned by a dasd_device cancel it */
2991 		if (cqr->status >= DASD_CQR_QUEUED)
2992 			rc = dasd_cancel_req(cqr);
2993 		if (rc < 0)
2994 			break;
2995 		/* Rechain request (including erp chain) so it won't be
2996 		 * touched by the dasd_block_tasklet anymore.
2997 		 * Replace the callback so we notice when the request
2998 		 * is returned from the dasd_device layer.
2999 		 */
3000 		cqr->callback = _dasd_wake_block_flush_cb;
3001 		for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
3002 			list_move_tail(&cqr->blocklist, &flush_queue);
3003 		if (i > 1)
3004 			/* moved more than one request - need to restart */
3005 			goto restart;
3006 	}
3007 	spin_unlock_bh(&block->queue_lock);
3008 	/* Now call the callback function of flushed requests */
3009 restart_cb:
3010 	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3011 		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3012 		/* Process finished ERP request. */
3013 		if (cqr->refers) {
3014 			spin_lock_bh(&block->queue_lock);
3015 			__dasd_process_erp(block->base, cqr);
3016 			spin_unlock_bh(&block->queue_lock);
3017 			/* restart list_for_xx loop since dasd_process_erp
3018 			 * might remove multiple elements */
3019 			goto restart_cb;
3020 		}
3021 		/* call the callback function */
3022 		spin_lock_irqsave(&cqr->dq->lock, flags);
3023 		cqr->endclk = get_tod_clock();
3024 		list_del_init(&cqr->blocklist);
3025 		__dasd_cleanup_cqr(cqr);
3026 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3027 	}
3028 	return rc;
3029 }
3030 
3031 /*
3032  * Schedules a call to dasd_tasklet over the device tasklet.
3033  */
3034 void dasd_schedule_block_bh(struct dasd_block *block)
3035 {
3036 	/* Protect against rescheduling. */
3037 	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3038 		return;
3039 	/* life cycle of block is bound to it's base device */
3040 	dasd_get_device(block->base);
3041 	tasklet_hi_schedule(&block->tasklet);
3042 }
3043 EXPORT_SYMBOL(dasd_schedule_block_bh);
3044 
3045 
3046 /*
3047  * SECTION: external block device operations
3048  * (request queue handling, open, release, etc.)
3049  */
3050 
3051 /*
3052  * Dasd request queue function. Called from ll_rw_blk.c
3053  */
3054 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3055 				    const struct blk_mq_queue_data *qd)
3056 {
3057 	struct dasd_block *block = hctx->queue->queuedata;
3058 	struct dasd_queue *dq = hctx->driver_data;
3059 	struct request *req = qd->rq;
3060 	struct dasd_device *basedev;
3061 	struct dasd_ccw_req *cqr;
3062 	blk_status_t rc = BLK_STS_OK;
3063 
3064 	basedev = block->base;
3065 	spin_lock_irq(&dq->lock);
3066 	if (basedev->state < DASD_STATE_READY) {
3067 		DBF_DEV_EVENT(DBF_ERR, basedev,
3068 			      "device not ready for request %p", req);
3069 		rc = BLK_STS_IOERR;
3070 		goto out;
3071 	}
3072 
3073 	/*
3074 	 * if device is stopped do not fetch new requests
3075 	 * except failfast is active which will let requests fail
3076 	 * immediately in __dasd_block_start_head()
3077 	 */
3078 	if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3079 		DBF_DEV_EVENT(DBF_ERR, basedev,
3080 			      "device stopped request %p", req);
3081 		rc = BLK_STS_RESOURCE;
3082 		goto out;
3083 	}
3084 
3085 	if (basedev->features & DASD_FEATURE_READONLY &&
3086 	    rq_data_dir(req) == WRITE) {
3087 		DBF_DEV_EVENT(DBF_ERR, basedev,
3088 			      "Rejecting write request %p", req);
3089 		rc = BLK_STS_IOERR;
3090 		goto out;
3091 	}
3092 
3093 	if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3094 	    (basedev->features & DASD_FEATURE_FAILFAST ||
3095 	     blk_noretry_request(req))) {
3096 		DBF_DEV_EVENT(DBF_ERR, basedev,
3097 			      "Rejecting failfast request %p", req);
3098 		rc = BLK_STS_IOERR;
3099 		goto out;
3100 	}
3101 
3102 	cqr = basedev->discipline->build_cp(basedev, block, req);
3103 	if (IS_ERR(cqr)) {
3104 		if (PTR_ERR(cqr) == -EBUSY ||
3105 		    PTR_ERR(cqr) == -ENOMEM ||
3106 		    PTR_ERR(cqr) == -EAGAIN) {
3107 			rc = BLK_STS_RESOURCE;
3108 			goto out;
3109 		}
3110 		DBF_DEV_EVENT(DBF_ERR, basedev,
3111 			      "CCW creation failed (rc=%ld) on request %p",
3112 			      PTR_ERR(cqr), req);
3113 		rc = BLK_STS_IOERR;
3114 		goto out;
3115 	}
3116 	/*
3117 	 *  Note: callback is set to dasd_return_cqr_cb in
3118 	 * __dasd_block_start_head to cover erp requests as well
3119 	 */
3120 	cqr->callback_data = req;
3121 	cqr->status = DASD_CQR_FILLED;
3122 	cqr->dq = dq;
3123 
3124 	blk_mq_start_request(req);
3125 	spin_lock(&block->queue_lock);
3126 	list_add_tail(&cqr->blocklist, &block->ccw_queue);
3127 	INIT_LIST_HEAD(&cqr->devlist);
3128 	dasd_profile_start(block, cqr, req);
3129 	dasd_schedule_block_bh(block);
3130 	spin_unlock(&block->queue_lock);
3131 
3132 out:
3133 	spin_unlock_irq(&dq->lock);
3134 	return rc;
3135 }
3136 
3137 /*
3138  * Block timeout callback, called from the block layer
3139  *
3140  * Return values:
3141  * BLK_EH_RESET_TIMER if the request should be left running
3142  * BLK_EH_DONE if the request is handled or terminated
3143  *		      by the driver.
3144  */
3145 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3146 {
3147 	struct dasd_block *block = req->q->queuedata;
3148 	struct dasd_device *device;
3149 	struct dasd_ccw_req *cqr;
3150 	unsigned long flags;
3151 	int rc = 0;
3152 
3153 	cqr = blk_mq_rq_to_pdu(req);
3154 	if (!cqr)
3155 		return BLK_EH_DONE;
3156 
3157 	spin_lock_irqsave(&cqr->dq->lock, flags);
3158 	device = cqr->startdev ? cqr->startdev : block->base;
3159 	if (!device->blk_timeout) {
3160 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3161 		return BLK_EH_RESET_TIMER;
3162 	}
3163 	DBF_DEV_EVENT(DBF_WARNING, device,
3164 		      " dasd_times_out cqr %p status %x",
3165 		      cqr, cqr->status);
3166 
3167 	spin_lock(&block->queue_lock);
3168 	spin_lock(get_ccwdev_lock(device->cdev));
3169 	cqr->retries = -1;
3170 	cqr->intrc = -ETIMEDOUT;
3171 	if (cqr->status >= DASD_CQR_QUEUED) {
3172 		rc = __dasd_cancel_req(cqr);
3173 	} else if (cqr->status == DASD_CQR_FILLED ||
3174 		   cqr->status == DASD_CQR_NEED_ERP) {
3175 		cqr->status = DASD_CQR_TERMINATED;
3176 	} else if (cqr->status == DASD_CQR_IN_ERP) {
3177 		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3178 
3179 		list_for_each_entry_safe(searchcqr, nextcqr,
3180 					 &block->ccw_queue, blocklist) {
3181 			tmpcqr = searchcqr;
3182 			while (tmpcqr->refers)
3183 				tmpcqr = tmpcqr->refers;
3184 			if (tmpcqr != cqr)
3185 				continue;
3186 			/* searchcqr is an ERP request for cqr */
3187 			searchcqr->retries = -1;
3188 			searchcqr->intrc = -ETIMEDOUT;
3189 			if (searchcqr->status >= DASD_CQR_QUEUED) {
3190 				rc = __dasd_cancel_req(searchcqr);
3191 			} else if ((searchcqr->status == DASD_CQR_FILLED) ||
3192 				   (searchcqr->status == DASD_CQR_NEED_ERP)) {
3193 				searchcqr->status = DASD_CQR_TERMINATED;
3194 				rc = 0;
3195 			} else if (searchcqr->status == DASD_CQR_IN_ERP) {
3196 				/*
3197 				 * Shouldn't happen; most recent ERP
3198 				 * request is at the front of queue
3199 				 */
3200 				continue;
3201 			}
3202 			break;
3203 		}
3204 	}
3205 	spin_unlock(get_ccwdev_lock(device->cdev));
3206 	dasd_schedule_block_bh(block);
3207 	spin_unlock(&block->queue_lock);
3208 	spin_unlock_irqrestore(&cqr->dq->lock, flags);
3209 
3210 	return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3211 }
3212 
3213 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3214 			  unsigned int idx)
3215 {
3216 	struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3217 
3218 	if (!dq)
3219 		return -ENOMEM;
3220 
3221 	spin_lock_init(&dq->lock);
3222 	hctx->driver_data = dq;
3223 
3224 	return 0;
3225 }
3226 
3227 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3228 {
3229 	kfree(hctx->driver_data);
3230 	hctx->driver_data = NULL;
3231 }
3232 
3233 static void dasd_request_done(struct request *req)
3234 {
3235 	blk_mq_end_request(req, 0);
3236 	blk_mq_run_hw_queues(req->q, true);
3237 }
3238 
3239 static struct blk_mq_ops dasd_mq_ops = {
3240 	.queue_rq = do_dasd_request,
3241 	.complete = dasd_request_done,
3242 	.timeout = dasd_times_out,
3243 	.init_hctx = dasd_init_hctx,
3244 	.exit_hctx = dasd_exit_hctx,
3245 };
3246 
3247 /*
3248  * Allocate and initialize request queue and default I/O scheduler.
3249  */
3250 static int dasd_alloc_queue(struct dasd_block *block)
3251 {
3252 	int rc;
3253 
3254 	block->tag_set.ops = &dasd_mq_ops;
3255 	block->tag_set.cmd_size = sizeof(struct dasd_ccw_req);
3256 	block->tag_set.nr_hw_queues = nr_hw_queues;
3257 	block->tag_set.queue_depth = queue_depth;
3258 	block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3259 	block->tag_set.numa_node = NUMA_NO_NODE;
3260 
3261 	rc = blk_mq_alloc_tag_set(&block->tag_set);
3262 	if (rc)
3263 		return rc;
3264 
3265 	block->request_queue = blk_mq_init_queue(&block->tag_set);
3266 	if (IS_ERR(block->request_queue))
3267 		return PTR_ERR(block->request_queue);
3268 
3269 	block->request_queue->queuedata = block;
3270 
3271 	return 0;
3272 }
3273 
3274 /*
3275  * Deactivate and free request queue.
3276  */
3277 static void dasd_free_queue(struct dasd_block *block)
3278 {
3279 	if (block->request_queue) {
3280 		blk_cleanup_queue(block->request_queue);
3281 		blk_mq_free_tag_set(&block->tag_set);
3282 		block->request_queue = NULL;
3283 	}
3284 }
3285 
3286 static int dasd_open(struct block_device *bdev, fmode_t mode)
3287 {
3288 	struct dasd_device *base;
3289 	int rc;
3290 
3291 	base = dasd_device_from_gendisk(bdev->bd_disk);
3292 	if (!base)
3293 		return -ENODEV;
3294 
3295 	atomic_inc(&base->block->open_count);
3296 	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3297 		rc = -ENODEV;
3298 		goto unlock;
3299 	}
3300 
3301 	if (!try_module_get(base->discipline->owner)) {
3302 		rc = -EINVAL;
3303 		goto unlock;
3304 	}
3305 
3306 	if (dasd_probeonly) {
3307 		dev_info(&base->cdev->dev,
3308 			 "Accessing the DASD failed because it is in "
3309 			 "probeonly mode\n");
3310 		rc = -EPERM;
3311 		goto out;
3312 	}
3313 
3314 	if (base->state <= DASD_STATE_BASIC) {
3315 		DBF_DEV_EVENT(DBF_ERR, base, " %s",
3316 			      " Cannot open unrecognized device");
3317 		rc = -ENODEV;
3318 		goto out;
3319 	}
3320 
3321 	if ((mode & FMODE_WRITE) &&
3322 	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3323 	     (base->features & DASD_FEATURE_READONLY))) {
3324 		rc = -EROFS;
3325 		goto out;
3326 	}
3327 
3328 	dasd_put_device(base);
3329 	return 0;
3330 
3331 out:
3332 	module_put(base->discipline->owner);
3333 unlock:
3334 	atomic_dec(&base->block->open_count);
3335 	dasd_put_device(base);
3336 	return rc;
3337 }
3338 
3339 static void dasd_release(struct gendisk *disk, fmode_t mode)
3340 {
3341 	struct dasd_device *base = dasd_device_from_gendisk(disk);
3342 	if (base) {
3343 		atomic_dec(&base->block->open_count);
3344 		module_put(base->discipline->owner);
3345 		dasd_put_device(base);
3346 	}
3347 }
3348 
3349 /*
3350  * Return disk geometry.
3351  */
3352 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3353 {
3354 	struct dasd_device *base;
3355 
3356 	base = dasd_device_from_gendisk(bdev->bd_disk);
3357 	if (!base)
3358 		return -ENODEV;
3359 
3360 	if (!base->discipline ||
3361 	    !base->discipline->fill_geometry) {
3362 		dasd_put_device(base);
3363 		return -EINVAL;
3364 	}
3365 	base->discipline->fill_geometry(base->block, geo);
3366 	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3367 	dasd_put_device(base);
3368 	return 0;
3369 }
3370 
3371 const struct block_device_operations
3372 dasd_device_operations = {
3373 	.owner		= THIS_MODULE,
3374 	.open		= dasd_open,
3375 	.release	= dasd_release,
3376 	.ioctl		= dasd_ioctl,
3377 	.compat_ioctl	= dasd_ioctl,
3378 	.getgeo		= dasd_getgeo,
3379 };
3380 
3381 /*******************************************************************************
3382  * end of block device operations
3383  */
3384 
3385 static void
3386 dasd_exit(void)
3387 {
3388 #ifdef CONFIG_PROC_FS
3389 	dasd_proc_exit();
3390 #endif
3391 	dasd_eer_exit();
3392 	kmem_cache_destroy(dasd_page_cache);
3393 	dasd_page_cache = NULL;
3394 	dasd_gendisk_exit();
3395 	dasd_devmap_exit();
3396 	if (dasd_debug_area != NULL) {
3397 		debug_unregister(dasd_debug_area);
3398 		dasd_debug_area = NULL;
3399 	}
3400 	dasd_statistics_removeroot();
3401 }
3402 
3403 /*
3404  * SECTION: common functions for ccw_driver use
3405  */
3406 
3407 /*
3408  * Is the device read-only?
3409  * Note that this function does not report the setting of the
3410  * readonly device attribute, but how it is configured in z/VM.
3411  */
3412 int dasd_device_is_ro(struct dasd_device *device)
3413 {
3414 	struct ccw_dev_id dev_id;
3415 	struct diag210 diag_data;
3416 	int rc;
3417 
3418 	if (!MACHINE_IS_VM)
3419 		return 0;
3420 	ccw_device_get_id(device->cdev, &dev_id);
3421 	memset(&diag_data, 0, sizeof(diag_data));
3422 	diag_data.vrdcdvno = dev_id.devno;
3423 	diag_data.vrdclen = sizeof(diag_data);
3424 	rc = diag210(&diag_data);
3425 	if (rc == 0 || rc == 2) {
3426 		return diag_data.vrdcvfla & 0x80;
3427 	} else {
3428 		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3429 			  dev_id.devno, rc);
3430 		return 0;
3431 	}
3432 }
3433 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3434 
3435 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3436 {
3437 	struct ccw_device *cdev = data;
3438 	int ret;
3439 
3440 	ret = ccw_device_set_online(cdev);
3441 	if (ret)
3442 		pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3443 			dev_name(&cdev->dev), ret);
3444 }
3445 
3446 /*
3447  * Initial attempt at a probe function. this can be simplified once
3448  * the other detection code is gone.
3449  */
3450 int dasd_generic_probe(struct ccw_device *cdev,
3451 		       struct dasd_discipline *discipline)
3452 {
3453 	int ret;
3454 
3455 	ret = dasd_add_sysfs_files(cdev);
3456 	if (ret) {
3457 		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3458 				"dasd_generic_probe: could not add "
3459 				"sysfs entries");
3460 		return ret;
3461 	}
3462 	cdev->handler = &dasd_int_handler;
3463 
3464 	/*
3465 	 * Automatically online either all dasd devices (dasd_autodetect)
3466 	 * or all devices specified with dasd= parameters during
3467 	 * initial probe.
3468 	 */
3469 	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3470 	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3471 		async_schedule(dasd_generic_auto_online, cdev);
3472 	return 0;
3473 }
3474 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3475 
3476 void dasd_generic_free_discipline(struct dasd_device *device)
3477 {
3478 	/* Forget the discipline information. */
3479 	if (device->discipline) {
3480 		if (device->discipline->uncheck_device)
3481 			device->discipline->uncheck_device(device);
3482 		module_put(device->discipline->owner);
3483 		device->discipline = NULL;
3484 	}
3485 	if (device->base_discipline) {
3486 		module_put(device->base_discipline->owner);
3487 		device->base_discipline = NULL;
3488 	}
3489 }
3490 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3491 
3492 /*
3493  * This will one day be called from a global not_oper handler.
3494  * It is also used by driver_unregister during module unload.
3495  */
3496 void dasd_generic_remove(struct ccw_device *cdev)
3497 {
3498 	struct dasd_device *device;
3499 	struct dasd_block *block;
3500 
3501 	cdev->handler = NULL;
3502 
3503 	device = dasd_device_from_cdev(cdev);
3504 	if (IS_ERR(device)) {
3505 		dasd_remove_sysfs_files(cdev);
3506 		return;
3507 	}
3508 	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3509 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3510 		/* Already doing offline processing */
3511 		dasd_put_device(device);
3512 		dasd_remove_sysfs_files(cdev);
3513 		return;
3514 	}
3515 	/*
3516 	 * This device is removed unconditionally. Set offline
3517 	 * flag to prevent dasd_open from opening it while it is
3518 	 * no quite down yet.
3519 	 */
3520 	dasd_set_target_state(device, DASD_STATE_NEW);
3521 	/* dasd_delete_device destroys the device reference. */
3522 	block = device->block;
3523 	dasd_delete_device(device);
3524 	/*
3525 	 * life cycle of block is bound to device, so delete it after
3526 	 * device was safely removed
3527 	 */
3528 	if (block)
3529 		dasd_free_block(block);
3530 
3531 	dasd_remove_sysfs_files(cdev);
3532 }
3533 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3534 
3535 /*
3536  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3537  * the device is detected for the first time and is supposed to be used
3538  * or the user has started activation through sysfs.
3539  */
3540 int dasd_generic_set_online(struct ccw_device *cdev,
3541 			    struct dasd_discipline *base_discipline)
3542 {
3543 	struct dasd_discipline *discipline;
3544 	struct dasd_device *device;
3545 	int rc;
3546 
3547 	/* first online clears initial online feature flag */
3548 	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3549 	device = dasd_create_device(cdev);
3550 	if (IS_ERR(device))
3551 		return PTR_ERR(device);
3552 
3553 	discipline = base_discipline;
3554 	if (device->features & DASD_FEATURE_USEDIAG) {
3555 	  	if (!dasd_diag_discipline_pointer) {
3556 			/* Try to load the required module. */
3557 			rc = request_module(DASD_DIAG_MOD);
3558 			if (rc) {
3559 				pr_warn("%s Setting the DASD online failed "
3560 					"because the required module %s "
3561 					"could not be loaded (rc=%d)\n",
3562 					dev_name(&cdev->dev), DASD_DIAG_MOD,
3563 					rc);
3564 				dasd_delete_device(device);
3565 				return -ENODEV;
3566 			}
3567 		}
3568 		/* Module init could have failed, so check again here after
3569 		 * request_module(). */
3570 		if (!dasd_diag_discipline_pointer) {
3571 			pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3572 				dev_name(&cdev->dev));
3573 			dasd_delete_device(device);
3574 			return -ENODEV;
3575 		}
3576 		discipline = dasd_diag_discipline_pointer;
3577 	}
3578 	if (!try_module_get(base_discipline->owner)) {
3579 		dasd_delete_device(device);
3580 		return -EINVAL;
3581 	}
3582 	if (!try_module_get(discipline->owner)) {
3583 		module_put(base_discipline->owner);
3584 		dasd_delete_device(device);
3585 		return -EINVAL;
3586 	}
3587 	device->base_discipline = base_discipline;
3588 	device->discipline = discipline;
3589 
3590 	/* check_device will allocate block device if necessary */
3591 	rc = discipline->check_device(device);
3592 	if (rc) {
3593 		pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3594 			dev_name(&cdev->dev), discipline->name, rc);
3595 		module_put(discipline->owner);
3596 		module_put(base_discipline->owner);
3597 		dasd_delete_device(device);
3598 		return rc;
3599 	}
3600 
3601 	dasd_set_target_state(device, DASD_STATE_ONLINE);
3602 	if (device->state <= DASD_STATE_KNOWN) {
3603 		pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3604 			dev_name(&cdev->dev));
3605 		rc = -ENODEV;
3606 		dasd_set_target_state(device, DASD_STATE_NEW);
3607 		if (device->block)
3608 			dasd_free_block(device->block);
3609 		dasd_delete_device(device);
3610 	} else
3611 		pr_debug("dasd_generic device %s found\n",
3612 				dev_name(&cdev->dev));
3613 
3614 	wait_event(dasd_init_waitq, _wait_for_device(device));
3615 
3616 	dasd_put_device(device);
3617 	return rc;
3618 }
3619 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3620 
3621 int dasd_generic_set_offline(struct ccw_device *cdev)
3622 {
3623 	struct dasd_device *device;
3624 	struct dasd_block *block;
3625 	int max_count, open_count, rc;
3626 	unsigned long flags;
3627 
3628 	rc = 0;
3629 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3630 	device = dasd_device_from_cdev_locked(cdev);
3631 	if (IS_ERR(device)) {
3632 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3633 		return PTR_ERR(device);
3634 	}
3635 
3636 	/*
3637 	 * We must make sure that this device is currently not in use.
3638 	 * The open_count is increased for every opener, that includes
3639 	 * the blkdev_get in dasd_scan_partitions. We are only interested
3640 	 * in the other openers.
3641 	 */
3642 	if (device->block) {
3643 		max_count = device->block->bdev ? 0 : -1;
3644 		open_count = atomic_read(&device->block->open_count);
3645 		if (open_count > max_count) {
3646 			if (open_count > 0)
3647 				pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3648 					dev_name(&cdev->dev), open_count);
3649 			else
3650 				pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3651 					dev_name(&cdev->dev));
3652 			rc = -EBUSY;
3653 			goto out_err;
3654 		}
3655 	}
3656 
3657 	/*
3658 	 * Test if the offline processing is already running and exit if so.
3659 	 * If a safe offline is being processed this could only be a normal
3660 	 * offline that should be able to overtake the safe offline and
3661 	 * cancel any I/O we do not want to wait for any longer
3662 	 */
3663 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3664 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3665 			clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3666 				  &device->flags);
3667 		} else {
3668 			rc = -EBUSY;
3669 			goto out_err;
3670 		}
3671 	}
3672 	set_bit(DASD_FLAG_OFFLINE, &device->flags);
3673 
3674 	/*
3675 	 * if safe_offline is called set safe_offline_running flag and
3676 	 * clear safe_offline so that a call to normal offline
3677 	 * can overrun safe_offline processing
3678 	 */
3679 	if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3680 	    !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3681 		/* need to unlock here to wait for outstanding I/O */
3682 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3683 		/*
3684 		 * If we want to set the device safe offline all IO operations
3685 		 * should be finished before continuing the offline process
3686 		 * so sync bdev first and then wait for our queues to become
3687 		 * empty
3688 		 */
3689 		if (device->block) {
3690 			rc = fsync_bdev(device->block->bdev);
3691 			if (rc != 0)
3692 				goto interrupted;
3693 		}
3694 		dasd_schedule_device_bh(device);
3695 		rc = wait_event_interruptible(shutdown_waitq,
3696 					      _wait_for_empty_queues(device));
3697 		if (rc != 0)
3698 			goto interrupted;
3699 
3700 		/*
3701 		 * check if a normal offline process overtook the offline
3702 		 * processing in this case simply do nothing beside returning
3703 		 * that we got interrupted
3704 		 * otherwise mark safe offline as not running any longer and
3705 		 * continue with normal offline
3706 		 */
3707 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3708 		if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3709 			rc = -ERESTARTSYS;
3710 			goto out_err;
3711 		}
3712 		clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3713 	}
3714 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3715 
3716 	dasd_set_target_state(device, DASD_STATE_NEW);
3717 	/* dasd_delete_device destroys the device reference. */
3718 	block = device->block;
3719 	dasd_delete_device(device);
3720 	/*
3721 	 * life cycle of block is bound to device, so delete it after
3722 	 * device was safely removed
3723 	 */
3724 	if (block)
3725 		dasd_free_block(block);
3726 
3727 	return 0;
3728 
3729 interrupted:
3730 	/* interrupted by signal */
3731 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3732 	clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3733 	clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3734 out_err:
3735 	dasd_put_device(device);
3736 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3737 	return rc;
3738 }
3739 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3740 
3741 int dasd_generic_last_path_gone(struct dasd_device *device)
3742 {
3743 	struct dasd_ccw_req *cqr;
3744 
3745 	dev_warn(&device->cdev->dev, "No operational channel path is left "
3746 		 "for the device\n");
3747 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3748 	/* First of all call extended error reporting. */
3749 	dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3750 
3751 	if (device->state < DASD_STATE_BASIC)
3752 		return 0;
3753 	/* Device is active. We want to keep it. */
3754 	list_for_each_entry(cqr, &device->ccw_queue, devlist)
3755 		if ((cqr->status == DASD_CQR_IN_IO) ||
3756 		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3757 			cqr->status = DASD_CQR_QUEUED;
3758 			cqr->retries++;
3759 		}
3760 	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3761 	dasd_device_clear_timer(device);
3762 	dasd_schedule_device_bh(device);
3763 	return 1;
3764 }
3765 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3766 
3767 int dasd_generic_path_operational(struct dasd_device *device)
3768 {
3769 	dev_info(&device->cdev->dev, "A channel path to the device has become "
3770 		 "operational\n");
3771 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3772 	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3773 	dasd_schedule_device_bh(device);
3774 	if (device->block) {
3775 		dasd_schedule_block_bh(device->block);
3776 		if (device->block->request_queue)
3777 			blk_mq_run_hw_queues(device->block->request_queue,
3778 					     true);
3779 		}
3780 
3781 	if (!device->stopped)
3782 		wake_up(&generic_waitq);
3783 
3784 	return 1;
3785 }
3786 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3787 
3788 int dasd_generic_notify(struct ccw_device *cdev, int event)
3789 {
3790 	struct dasd_device *device;
3791 	int ret;
3792 
3793 	device = dasd_device_from_cdev_locked(cdev);
3794 	if (IS_ERR(device))
3795 		return 0;
3796 	ret = 0;
3797 	switch (event) {
3798 	case CIO_GONE:
3799 	case CIO_BOXED:
3800 	case CIO_NO_PATH:
3801 		dasd_path_no_path(device);
3802 		ret = dasd_generic_last_path_gone(device);
3803 		break;
3804 	case CIO_OPER:
3805 		ret = 1;
3806 		if (dasd_path_get_opm(device))
3807 			ret = dasd_generic_path_operational(device);
3808 		break;
3809 	}
3810 	dasd_put_device(device);
3811 	return ret;
3812 }
3813 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3814 
3815 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3816 {
3817 	struct dasd_device *device;
3818 	int chp, oldopm, hpfpm, ifccpm;
3819 
3820 	device = dasd_device_from_cdev_locked(cdev);
3821 	if (IS_ERR(device))
3822 		return;
3823 
3824 	oldopm = dasd_path_get_opm(device);
3825 	for (chp = 0; chp < 8; chp++) {
3826 		if (path_event[chp] & PE_PATH_GONE) {
3827 			dasd_path_notoper(device, chp);
3828 		}
3829 		if (path_event[chp] & PE_PATH_AVAILABLE) {
3830 			dasd_path_available(device, chp);
3831 			dasd_schedule_device_bh(device);
3832 		}
3833 		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3834 			if (!dasd_path_is_operational(device, chp) &&
3835 			    !dasd_path_need_verify(device, chp)) {
3836 				/*
3837 				 * we can not establish a pathgroup on an
3838 				 * unavailable path, so trigger a path
3839 				 * verification first
3840 				 */
3841 			dasd_path_available(device, chp);
3842 			dasd_schedule_device_bh(device);
3843 			}
3844 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3845 				      "Pathgroup re-established\n");
3846 			if (device->discipline->kick_validate)
3847 				device->discipline->kick_validate(device);
3848 		}
3849 	}
3850 	hpfpm = dasd_path_get_hpfpm(device);
3851 	ifccpm = dasd_path_get_ifccpm(device);
3852 	if (!dasd_path_get_opm(device) && hpfpm) {
3853 		/*
3854 		 * device has no operational paths but at least one path is
3855 		 * disabled due to HPF errors
3856 		 * disable HPF at all and use the path(s) again
3857 		 */
3858 		if (device->discipline->disable_hpf)
3859 			device->discipline->disable_hpf(device);
3860 		dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3861 		dasd_path_set_tbvpm(device, hpfpm);
3862 		dasd_schedule_device_bh(device);
3863 		dasd_schedule_requeue(device);
3864 	} else if (!dasd_path_get_opm(device) && ifccpm) {
3865 		/*
3866 		 * device has no operational paths but at least one path is
3867 		 * disabled due to IFCC errors
3868 		 * trigger path verification on paths with IFCC errors
3869 		 */
3870 		dasd_path_set_tbvpm(device, ifccpm);
3871 		dasd_schedule_device_bh(device);
3872 	}
3873 	if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3874 		dev_warn(&device->cdev->dev,
3875 			 "No verified channel paths remain for the device\n");
3876 		DBF_DEV_EVENT(DBF_WARNING, device,
3877 			      "%s", "last verified path gone");
3878 		dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3879 		dasd_device_set_stop_bits(device,
3880 					  DASD_STOPPED_DC_WAIT);
3881 	}
3882 	dasd_put_device(device);
3883 }
3884 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3885 
3886 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3887 {
3888 	if (!dasd_path_get_opm(device) && lpm) {
3889 		dasd_path_set_opm(device, lpm);
3890 		dasd_generic_path_operational(device);
3891 	} else
3892 		dasd_path_add_opm(device, lpm);
3893 	return 0;
3894 }
3895 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3896 
3897 void dasd_generic_space_exhaust(struct dasd_device *device,
3898 				struct dasd_ccw_req *cqr)
3899 {
3900 	dasd_eer_write(device, NULL, DASD_EER_NOSPC);
3901 
3902 	if (device->state < DASD_STATE_BASIC)
3903 		return;
3904 
3905 	if (cqr->status == DASD_CQR_IN_IO ||
3906 	    cqr->status == DASD_CQR_CLEAR_PENDING) {
3907 		cqr->status = DASD_CQR_QUEUED;
3908 		cqr->retries++;
3909 	}
3910 	dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3911 	dasd_device_clear_timer(device);
3912 	dasd_schedule_device_bh(device);
3913 }
3914 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3915 
3916 void dasd_generic_space_avail(struct dasd_device *device)
3917 {
3918 	dev_info(&device->cdev->dev, "Extent pool space is available\n");
3919 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3920 
3921 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3922 	dasd_schedule_device_bh(device);
3923 
3924 	if (device->block) {
3925 		dasd_schedule_block_bh(device->block);
3926 		if (device->block->request_queue)
3927 			blk_mq_run_hw_queues(device->block->request_queue, true);
3928 	}
3929 	if (!device->stopped)
3930 		wake_up(&generic_waitq);
3931 }
3932 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3933 
3934 /*
3935  * clear active requests and requeue them to block layer if possible
3936  */
3937 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3938 {
3939 	struct list_head requeue_queue;
3940 	struct dasd_ccw_req *cqr, *n;
3941 	struct dasd_ccw_req *refers;
3942 	int rc;
3943 
3944 	INIT_LIST_HEAD(&requeue_queue);
3945 	spin_lock_irq(get_ccwdev_lock(device->cdev));
3946 	rc = 0;
3947 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3948 		/* Check status and move request to flush_queue */
3949 		if (cqr->status == DASD_CQR_IN_IO) {
3950 			rc = device->discipline->term_IO(cqr);
3951 			if (rc) {
3952 				/* unable to terminate requeust */
3953 				dev_err(&device->cdev->dev,
3954 					"Unable to terminate request %p "
3955 					"on suspend\n", cqr);
3956 				spin_unlock_irq(get_ccwdev_lock(device->cdev));
3957 				dasd_put_device(device);
3958 				return rc;
3959 			}
3960 		}
3961 		list_move_tail(&cqr->devlist, &requeue_queue);
3962 	}
3963 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
3964 
3965 	list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3966 		wait_event(dasd_flush_wq,
3967 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
3968 
3969 		/*
3970 		 * requeue requests to blocklayer will only work
3971 		 * for block device requests
3972 		 */
3973 		if (_dasd_requeue_request(cqr))
3974 			continue;
3975 
3976 		/* remove requests from device and block queue */
3977 		list_del_init(&cqr->devlist);
3978 		while (cqr->refers != NULL) {
3979 			refers = cqr->refers;
3980 			/* remove the request from the block queue */
3981 			list_del(&cqr->blocklist);
3982 			/* free the finished erp request */
3983 			dasd_free_erp_request(cqr, cqr->memdev);
3984 			cqr = refers;
3985 		}
3986 
3987 		/*
3988 		 * _dasd_requeue_request already checked for a valid
3989 		 * blockdevice, no need to check again
3990 		 * all erp requests (cqr->refers) have a cqr->block
3991 		 * pointer copy from the original cqr
3992 		 */
3993 		list_del_init(&cqr->blocklist);
3994 		cqr->block->base->discipline->free_cp(
3995 			cqr, (struct request *) cqr->callback_data);
3996 	}
3997 
3998 	/*
3999 	 * if requests remain then they are internal request
4000 	 * and go back to the device queue
4001 	 */
4002 	if (!list_empty(&requeue_queue)) {
4003 		/* move freeze_queue to start of the ccw_queue */
4004 		spin_lock_irq(get_ccwdev_lock(device->cdev));
4005 		list_splice_tail(&requeue_queue, &device->ccw_queue);
4006 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
4007 	}
4008 	dasd_schedule_device_bh(device);
4009 	return rc;
4010 }
4011 
4012 static void do_requeue_requests(struct work_struct *work)
4013 {
4014 	struct dasd_device *device = container_of(work, struct dasd_device,
4015 						  requeue_requests);
4016 	dasd_generic_requeue_all_requests(device);
4017 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
4018 	if (device->block)
4019 		dasd_schedule_block_bh(device->block);
4020 	dasd_put_device(device);
4021 }
4022 
4023 void dasd_schedule_requeue(struct dasd_device *device)
4024 {
4025 	dasd_get_device(device);
4026 	/* queue call to dasd_reload_device to the kernel event daemon. */
4027 	if (!schedule_work(&device->requeue_requests))
4028 		dasd_put_device(device);
4029 }
4030 EXPORT_SYMBOL(dasd_schedule_requeue);
4031 
4032 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4033 						   int rdc_buffer_size,
4034 						   int magic)
4035 {
4036 	struct dasd_ccw_req *cqr;
4037 	struct ccw1 *ccw;
4038 
4039 	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
4040 				   NULL);
4041 
4042 	if (IS_ERR(cqr)) {
4043 		/* internal error 13 - Allocating the RDC request failed*/
4044 		dev_err(&device->cdev->dev,
4045 			 "An error occurred in the DASD device driver, "
4046 			 "reason=%s\n", "13");
4047 		return cqr;
4048 	}
4049 
4050 	ccw = cqr->cpaddr;
4051 	ccw->cmd_code = CCW_CMD_RDC;
4052 	ccw->cda = (__u32)(addr_t) cqr->data;
4053 	ccw->flags = 0;
4054 	ccw->count = rdc_buffer_size;
4055 	cqr->startdev = device;
4056 	cqr->memdev = device;
4057 	cqr->expires = 10*HZ;
4058 	cqr->retries = 256;
4059 	cqr->buildclk = get_tod_clock();
4060 	cqr->status = DASD_CQR_FILLED;
4061 	return cqr;
4062 }
4063 
4064 
4065 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4066 				void *rdc_buffer, int rdc_buffer_size)
4067 {
4068 	int ret;
4069 	struct dasd_ccw_req *cqr;
4070 
4071 	cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4072 	if (IS_ERR(cqr))
4073 		return PTR_ERR(cqr);
4074 
4075 	ret = dasd_sleep_on(cqr);
4076 	if (ret == 0)
4077 		memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4078 	dasd_sfree_request(cqr, cqr->memdev);
4079 	return ret;
4080 }
4081 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4082 
4083 /*
4084  *   In command mode and transport mode we need to look for sense
4085  *   data in different places. The sense data itself is allways
4086  *   an array of 32 bytes, so we can unify the sense data access
4087  *   for both modes.
4088  */
4089 char *dasd_get_sense(struct irb *irb)
4090 {
4091 	struct tsb *tsb = NULL;
4092 	char *sense = NULL;
4093 
4094 	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4095 		if (irb->scsw.tm.tcw)
4096 			tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4097 					  irb->scsw.tm.tcw);
4098 		if (tsb && tsb->length == 64 && tsb->flags)
4099 			switch (tsb->flags & 0x07) {
4100 			case 1:	/* tsa_iostat */
4101 				sense = tsb->tsa.iostat.sense;
4102 				break;
4103 			case 2: /* tsa_ddpc */
4104 				sense = tsb->tsa.ddpc.sense;
4105 				break;
4106 			default:
4107 				/* currently we don't use interrogate data */
4108 				break;
4109 			}
4110 	} else if (irb->esw.esw0.erw.cons) {
4111 		sense = irb->ecw;
4112 	}
4113 	return sense;
4114 }
4115 EXPORT_SYMBOL_GPL(dasd_get_sense);
4116 
4117 void dasd_generic_shutdown(struct ccw_device *cdev)
4118 {
4119 	struct dasd_device *device;
4120 
4121 	device = dasd_device_from_cdev(cdev);
4122 	if (IS_ERR(device))
4123 		return;
4124 
4125 	if (device->block)
4126 		dasd_schedule_block_bh(device->block);
4127 
4128 	dasd_schedule_device_bh(device);
4129 
4130 	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4131 }
4132 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4133 
4134 static int __init dasd_init(void)
4135 {
4136 	int rc;
4137 
4138 	init_waitqueue_head(&dasd_init_waitq);
4139 	init_waitqueue_head(&dasd_flush_wq);
4140 	init_waitqueue_head(&generic_waitq);
4141 	init_waitqueue_head(&shutdown_waitq);
4142 
4143 	/* register 'common' DASD debug area, used for all DBF_XXX calls */
4144 	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4145 	if (dasd_debug_area == NULL) {
4146 		rc = -ENOMEM;
4147 		goto failed;
4148 	}
4149 	debug_register_view(dasd_debug_area, &debug_sprintf_view);
4150 	debug_set_level(dasd_debug_area, DBF_WARNING);
4151 
4152 	DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4153 
4154 	dasd_diag_discipline_pointer = NULL;
4155 
4156 	dasd_statistics_createroot();
4157 
4158 	rc = dasd_devmap_init();
4159 	if (rc)
4160 		goto failed;
4161 	rc = dasd_gendisk_init();
4162 	if (rc)
4163 		goto failed;
4164 	rc = dasd_parse();
4165 	if (rc)
4166 		goto failed;
4167 	rc = dasd_eer_init();
4168 	if (rc)
4169 		goto failed;
4170 #ifdef CONFIG_PROC_FS
4171 	rc = dasd_proc_init();
4172 	if (rc)
4173 		goto failed;
4174 #endif
4175 
4176 	return 0;
4177 failed:
4178 	pr_info("The DASD device driver could not be initialized\n");
4179 	dasd_exit();
4180 	return rc;
4181 }
4182 
4183 module_init(dasd_init);
4184 module_exit(dasd_exit);
4185