xref: /openbmc/linux/drivers/s390/block/dasd.c (revision 6aa7de05)
1 /*
2  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
3  *		    Horst Hummel <Horst.Hummel@de.ibm.com>
4  *		    Carsten Otte <Cotte@de.ibm.com>
5  *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
6  * Bugreports.to..: <Linux390@de.ibm.com>
7  * Copyright IBM Corp. 1999, 2009
8  */
9 
10 #define KMSG_COMPONENT "dasd"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/kmod.h>
14 #include <linux/init.h>
15 #include <linux/interrupt.h>
16 #include <linux/ctype.h>
17 #include <linux/major.h>
18 #include <linux/slab.h>
19 #include <linux/hdreg.h>
20 #include <linux/async.h>
21 #include <linux/mutex.h>
22 #include <linux/debugfs.h>
23 #include <linux/seq_file.h>
24 #include <linux/vmalloc.h>
25 
26 #include <asm/ccwdev.h>
27 #include <asm/ebcdic.h>
28 #include <asm/idals.h>
29 #include <asm/itcw.h>
30 #include <asm/diag.h>
31 
32 /* This is ugly... */
33 #define PRINTK_HEADER "dasd:"
34 
35 #include "dasd_int.h"
36 /*
37  * SECTION: Constant definitions to be used within this file
38  */
39 #define DASD_CHANQ_MAX_SIZE 4
40 
41 #define DASD_DIAG_MOD		"dasd_diag_mod"
42 
43 /*
44  * SECTION: exported variables of dasd.c
45  */
46 debug_info_t *dasd_debug_area;
47 EXPORT_SYMBOL(dasd_debug_area);
48 static struct dentry *dasd_debugfs_root_entry;
49 struct dasd_discipline *dasd_diag_discipline_pointer;
50 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
51 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
52 
53 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
54 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
55 		   " Copyright IBM Corp. 2000");
56 MODULE_SUPPORTED_DEVICE("dasd");
57 MODULE_LICENSE("GPL");
58 
59 /*
60  * SECTION: prototypes for static functions of dasd.c
61  */
62 static int  dasd_alloc_queue(struct dasd_block *);
63 static void dasd_setup_queue(struct dasd_block *);
64 static void dasd_free_queue(struct dasd_block *);
65 static int dasd_flush_block_queue(struct dasd_block *);
66 static void dasd_device_tasklet(struct dasd_device *);
67 static void dasd_block_tasklet(struct dasd_block *);
68 static void do_kick_device(struct work_struct *);
69 static void do_restore_device(struct work_struct *);
70 static void do_reload_device(struct work_struct *);
71 static void do_requeue_requests(struct work_struct *);
72 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
73 static void dasd_device_timeout(unsigned long);
74 static void dasd_block_timeout(unsigned long);
75 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
76 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
77 static void dasd_profile_exit(struct dasd_profile *);
78 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
79 static void dasd_hosts_exit(struct dasd_device *);
80 
81 /*
82  * SECTION: Operations on the device structure.
83  */
84 static wait_queue_head_t dasd_init_waitq;
85 static wait_queue_head_t dasd_flush_wq;
86 static wait_queue_head_t generic_waitq;
87 static wait_queue_head_t shutdown_waitq;
88 
89 /*
90  * Allocate memory for a new device structure.
91  */
92 struct dasd_device *dasd_alloc_device(void)
93 {
94 	struct dasd_device *device;
95 
96 	device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
97 	if (!device)
98 		return ERR_PTR(-ENOMEM);
99 
100 	/* Get two pages for normal block device operations. */
101 	device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
102 	if (!device->ccw_mem) {
103 		kfree(device);
104 		return ERR_PTR(-ENOMEM);
105 	}
106 	/* Get one page for error recovery. */
107 	device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
108 	if (!device->erp_mem) {
109 		free_pages((unsigned long) device->ccw_mem, 1);
110 		kfree(device);
111 		return ERR_PTR(-ENOMEM);
112 	}
113 
114 	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
115 	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
116 	spin_lock_init(&device->mem_lock);
117 	atomic_set(&device->tasklet_scheduled, 0);
118 	tasklet_init(&device->tasklet,
119 		     (void (*)(unsigned long)) dasd_device_tasklet,
120 		     (unsigned long) device);
121 	INIT_LIST_HEAD(&device->ccw_queue);
122 	init_timer(&device->timer);
123 	device->timer.function = dasd_device_timeout;
124 	device->timer.data = (unsigned long) device;
125 	INIT_WORK(&device->kick_work, do_kick_device);
126 	INIT_WORK(&device->restore_device, do_restore_device);
127 	INIT_WORK(&device->reload_device, do_reload_device);
128 	INIT_WORK(&device->requeue_requests, do_requeue_requests);
129 	device->state = DASD_STATE_NEW;
130 	device->target = DASD_STATE_NEW;
131 	mutex_init(&device->state_mutex);
132 	spin_lock_init(&device->profile.lock);
133 	return device;
134 }
135 
136 /*
137  * Free memory of a device structure.
138  */
139 void dasd_free_device(struct dasd_device *device)
140 {
141 	kfree(device->private);
142 	free_page((unsigned long) device->erp_mem);
143 	free_pages((unsigned long) device->ccw_mem, 1);
144 	kfree(device);
145 }
146 
147 /*
148  * Allocate memory for a new device structure.
149  */
150 struct dasd_block *dasd_alloc_block(void)
151 {
152 	struct dasd_block *block;
153 
154 	block = kzalloc(sizeof(*block), GFP_ATOMIC);
155 	if (!block)
156 		return ERR_PTR(-ENOMEM);
157 	/* open_count = 0 means device online but not in use */
158 	atomic_set(&block->open_count, -1);
159 
160 	atomic_set(&block->tasklet_scheduled, 0);
161 	tasklet_init(&block->tasklet,
162 		     (void (*)(unsigned long)) dasd_block_tasklet,
163 		     (unsigned long) block);
164 	INIT_LIST_HEAD(&block->ccw_queue);
165 	spin_lock_init(&block->queue_lock);
166 	init_timer(&block->timer);
167 	block->timer.function = dasd_block_timeout;
168 	block->timer.data = (unsigned long) block;
169 	spin_lock_init(&block->profile.lock);
170 
171 	return block;
172 }
173 EXPORT_SYMBOL_GPL(dasd_alloc_block);
174 
175 /*
176  * Free memory of a device structure.
177  */
178 void dasd_free_block(struct dasd_block *block)
179 {
180 	kfree(block);
181 }
182 EXPORT_SYMBOL_GPL(dasd_free_block);
183 
184 /*
185  * Make a new device known to the system.
186  */
187 static int dasd_state_new_to_known(struct dasd_device *device)
188 {
189 	int rc;
190 
191 	/*
192 	 * As long as the device is not in state DASD_STATE_NEW we want to
193 	 * keep the reference count > 0.
194 	 */
195 	dasd_get_device(device);
196 
197 	if (device->block) {
198 		rc = dasd_alloc_queue(device->block);
199 		if (rc) {
200 			dasd_put_device(device);
201 			return rc;
202 		}
203 	}
204 	device->state = DASD_STATE_KNOWN;
205 	return 0;
206 }
207 
208 /*
209  * Let the system forget about a device.
210  */
211 static int dasd_state_known_to_new(struct dasd_device *device)
212 {
213 	/* Disable extended error reporting for this device. */
214 	dasd_eer_disable(device);
215 	device->state = DASD_STATE_NEW;
216 
217 	if (device->block)
218 		dasd_free_queue(device->block);
219 
220 	/* Give up reference we took in dasd_state_new_to_known. */
221 	dasd_put_device(device);
222 	return 0;
223 }
224 
225 static struct dentry *dasd_debugfs_setup(const char *name,
226 					 struct dentry *base_dentry)
227 {
228 	struct dentry *pde;
229 
230 	if (!base_dentry)
231 		return NULL;
232 	pde = debugfs_create_dir(name, base_dentry);
233 	if (!pde || IS_ERR(pde))
234 		return NULL;
235 	return pde;
236 }
237 
238 /*
239  * Request the irq line for the device.
240  */
241 static int dasd_state_known_to_basic(struct dasd_device *device)
242 {
243 	struct dasd_block *block = device->block;
244 	int rc = 0;
245 
246 	/* Allocate and register gendisk structure. */
247 	if (block) {
248 		rc = dasd_gendisk_alloc(block);
249 		if (rc)
250 			return rc;
251 		block->debugfs_dentry =
252 			dasd_debugfs_setup(block->gdp->disk_name,
253 					   dasd_debugfs_root_entry);
254 		dasd_profile_init(&block->profile, block->debugfs_dentry);
255 		if (dasd_global_profile_level == DASD_PROFILE_ON)
256 			dasd_profile_on(&device->block->profile);
257 	}
258 	device->debugfs_dentry =
259 		dasd_debugfs_setup(dev_name(&device->cdev->dev),
260 				   dasd_debugfs_root_entry);
261 	dasd_profile_init(&device->profile, device->debugfs_dentry);
262 	dasd_hosts_init(device->debugfs_dentry, device);
263 
264 	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
265 	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
266 					    8 * sizeof(long));
267 	debug_register_view(device->debug_area, &debug_sprintf_view);
268 	debug_set_level(device->debug_area, DBF_WARNING);
269 	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
270 
271 	device->state = DASD_STATE_BASIC;
272 
273 	return rc;
274 }
275 
276 /*
277  * Release the irq line for the device. Terminate any running i/o.
278  */
279 static int dasd_state_basic_to_known(struct dasd_device *device)
280 {
281 	int rc;
282 
283 	if (device->discipline->basic_to_known) {
284 		rc = device->discipline->basic_to_known(device);
285 		if (rc)
286 			return rc;
287 	}
288 
289 	if (device->block) {
290 		dasd_profile_exit(&device->block->profile);
291 		debugfs_remove(device->block->debugfs_dentry);
292 		dasd_gendisk_free(device->block);
293 		dasd_block_clear_timer(device->block);
294 	}
295 	rc = dasd_flush_device_queue(device);
296 	if (rc)
297 		return rc;
298 	dasd_device_clear_timer(device);
299 	dasd_profile_exit(&device->profile);
300 	dasd_hosts_exit(device);
301 	debugfs_remove(device->debugfs_dentry);
302 	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
303 	if (device->debug_area != NULL) {
304 		debug_unregister(device->debug_area);
305 		device->debug_area = NULL;
306 	}
307 	device->state = DASD_STATE_KNOWN;
308 	return 0;
309 }
310 
311 /*
312  * Do the initial analysis. The do_analysis function may return
313  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
314  * until the discipline decides to continue the startup sequence
315  * by calling the function dasd_change_state. The eckd disciplines
316  * uses this to start a ccw that detects the format. The completion
317  * interrupt for this detection ccw uses the kernel event daemon to
318  * trigger the call to dasd_change_state. All this is done in the
319  * discipline code, see dasd_eckd.c.
320  * After the analysis ccw is done (do_analysis returned 0) the block
321  * device is setup.
322  * In case the analysis returns an error, the device setup is stopped
323  * (a fake disk was already added to allow formatting).
324  */
325 static int dasd_state_basic_to_ready(struct dasd_device *device)
326 {
327 	int rc;
328 	struct dasd_block *block;
329 	struct gendisk *disk;
330 
331 	rc = 0;
332 	block = device->block;
333 	/* make disk known with correct capacity */
334 	if (block) {
335 		if (block->base->discipline->do_analysis != NULL)
336 			rc = block->base->discipline->do_analysis(block);
337 		if (rc) {
338 			if (rc != -EAGAIN) {
339 				device->state = DASD_STATE_UNFMT;
340 				disk = device->block->gdp;
341 				kobject_uevent(&disk_to_dev(disk)->kobj,
342 					       KOBJ_CHANGE);
343 				goto out;
344 			}
345 			return rc;
346 		}
347 		dasd_setup_queue(block);
348 		set_capacity(block->gdp,
349 			     block->blocks << block->s2b_shift);
350 		device->state = DASD_STATE_READY;
351 		rc = dasd_scan_partitions(block);
352 		if (rc) {
353 			device->state = DASD_STATE_BASIC;
354 			return rc;
355 		}
356 	} else {
357 		device->state = DASD_STATE_READY;
358 	}
359 out:
360 	if (device->discipline->basic_to_ready)
361 		rc = device->discipline->basic_to_ready(device);
362 	return rc;
363 }
364 
365 static inline
366 int _wait_for_empty_queues(struct dasd_device *device)
367 {
368 	if (device->block)
369 		return list_empty(&device->ccw_queue) &&
370 			list_empty(&device->block->ccw_queue);
371 	else
372 		return list_empty(&device->ccw_queue);
373 }
374 
375 /*
376  * Remove device from block device layer. Destroy dirty buffers.
377  * Forget format information. Check if the target level is basic
378  * and if it is create fake disk for formatting.
379  */
380 static int dasd_state_ready_to_basic(struct dasd_device *device)
381 {
382 	int rc;
383 
384 	device->state = DASD_STATE_BASIC;
385 	if (device->block) {
386 		struct dasd_block *block = device->block;
387 		rc = dasd_flush_block_queue(block);
388 		if (rc) {
389 			device->state = DASD_STATE_READY;
390 			return rc;
391 		}
392 		dasd_destroy_partitions(block);
393 		block->blocks = 0;
394 		block->bp_block = 0;
395 		block->s2b_shift = 0;
396 	}
397 	return 0;
398 }
399 
400 /*
401  * Back to basic.
402  */
403 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
404 {
405 	device->state = DASD_STATE_BASIC;
406 	return 0;
407 }
408 
409 /*
410  * Make the device online and schedule the bottom half to start
411  * the requeueing of requests from the linux request queue to the
412  * ccw queue.
413  */
414 static int
415 dasd_state_ready_to_online(struct dasd_device * device)
416 {
417 	struct gendisk *disk;
418 	struct disk_part_iter piter;
419 	struct hd_struct *part;
420 
421 	device->state = DASD_STATE_ONLINE;
422 	if (device->block) {
423 		dasd_schedule_block_bh(device->block);
424 		if ((device->features & DASD_FEATURE_USERAW)) {
425 			disk = device->block->gdp;
426 			kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
427 			return 0;
428 		}
429 		disk = device->block->bdev->bd_disk;
430 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
431 		while ((part = disk_part_iter_next(&piter)))
432 			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
433 		disk_part_iter_exit(&piter);
434 	}
435 	return 0;
436 }
437 
438 /*
439  * Stop the requeueing of requests again.
440  */
441 static int dasd_state_online_to_ready(struct dasd_device *device)
442 {
443 	int rc;
444 	struct gendisk *disk;
445 	struct disk_part_iter piter;
446 	struct hd_struct *part;
447 
448 	if (device->discipline->online_to_ready) {
449 		rc = device->discipline->online_to_ready(device);
450 		if (rc)
451 			return rc;
452 	}
453 
454 	device->state = DASD_STATE_READY;
455 	if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
456 		disk = device->block->bdev->bd_disk;
457 		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
458 		while ((part = disk_part_iter_next(&piter)))
459 			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
460 		disk_part_iter_exit(&piter);
461 	}
462 	return 0;
463 }
464 
465 /*
466  * Device startup state changes.
467  */
468 static int dasd_increase_state(struct dasd_device *device)
469 {
470 	int rc;
471 
472 	rc = 0;
473 	if (device->state == DASD_STATE_NEW &&
474 	    device->target >= DASD_STATE_KNOWN)
475 		rc = dasd_state_new_to_known(device);
476 
477 	if (!rc &&
478 	    device->state == DASD_STATE_KNOWN &&
479 	    device->target >= DASD_STATE_BASIC)
480 		rc = dasd_state_known_to_basic(device);
481 
482 	if (!rc &&
483 	    device->state == DASD_STATE_BASIC &&
484 	    device->target >= DASD_STATE_READY)
485 		rc = dasd_state_basic_to_ready(device);
486 
487 	if (!rc &&
488 	    device->state == DASD_STATE_UNFMT &&
489 	    device->target > DASD_STATE_UNFMT)
490 		rc = -EPERM;
491 
492 	if (!rc &&
493 	    device->state == DASD_STATE_READY &&
494 	    device->target >= DASD_STATE_ONLINE)
495 		rc = dasd_state_ready_to_online(device);
496 
497 	return rc;
498 }
499 
500 /*
501  * Device shutdown state changes.
502  */
503 static int dasd_decrease_state(struct dasd_device *device)
504 {
505 	int rc;
506 
507 	rc = 0;
508 	if (device->state == DASD_STATE_ONLINE &&
509 	    device->target <= DASD_STATE_READY)
510 		rc = dasd_state_online_to_ready(device);
511 
512 	if (!rc &&
513 	    device->state == DASD_STATE_READY &&
514 	    device->target <= DASD_STATE_BASIC)
515 		rc = dasd_state_ready_to_basic(device);
516 
517 	if (!rc &&
518 	    device->state == DASD_STATE_UNFMT &&
519 	    device->target <= DASD_STATE_BASIC)
520 		rc = dasd_state_unfmt_to_basic(device);
521 
522 	if (!rc &&
523 	    device->state == DASD_STATE_BASIC &&
524 	    device->target <= DASD_STATE_KNOWN)
525 		rc = dasd_state_basic_to_known(device);
526 
527 	if (!rc &&
528 	    device->state == DASD_STATE_KNOWN &&
529 	    device->target <= DASD_STATE_NEW)
530 		rc = dasd_state_known_to_new(device);
531 
532 	return rc;
533 }
534 
535 /*
536  * This is the main startup/shutdown routine.
537  */
538 static void dasd_change_state(struct dasd_device *device)
539 {
540 	int rc;
541 
542 	if (device->state == device->target)
543 		/* Already where we want to go today... */
544 		return;
545 	if (device->state < device->target)
546 		rc = dasd_increase_state(device);
547 	else
548 		rc = dasd_decrease_state(device);
549 	if (rc == -EAGAIN)
550 		return;
551 	if (rc)
552 		device->target = device->state;
553 
554 	/* let user-space know that the device status changed */
555 	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
556 
557 	if (device->state == device->target)
558 		wake_up(&dasd_init_waitq);
559 }
560 
561 /*
562  * Kick starter for devices that did not complete the startup/shutdown
563  * procedure or were sleeping because of a pending state.
564  * dasd_kick_device will schedule a call do do_kick_device to the kernel
565  * event daemon.
566  */
567 static void do_kick_device(struct work_struct *work)
568 {
569 	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
570 	mutex_lock(&device->state_mutex);
571 	dasd_change_state(device);
572 	mutex_unlock(&device->state_mutex);
573 	dasd_schedule_device_bh(device);
574 	dasd_put_device(device);
575 }
576 
577 void dasd_kick_device(struct dasd_device *device)
578 {
579 	dasd_get_device(device);
580 	/* queue call to dasd_kick_device to the kernel event daemon. */
581 	if (!schedule_work(&device->kick_work))
582 		dasd_put_device(device);
583 }
584 EXPORT_SYMBOL(dasd_kick_device);
585 
586 /*
587  * dasd_reload_device will schedule a call do do_reload_device to the kernel
588  * event daemon.
589  */
590 static void do_reload_device(struct work_struct *work)
591 {
592 	struct dasd_device *device = container_of(work, struct dasd_device,
593 						  reload_device);
594 	device->discipline->reload(device);
595 	dasd_put_device(device);
596 }
597 
598 void dasd_reload_device(struct dasd_device *device)
599 {
600 	dasd_get_device(device);
601 	/* queue call to dasd_reload_device to the kernel event daemon. */
602 	if (!schedule_work(&device->reload_device))
603 		dasd_put_device(device);
604 }
605 EXPORT_SYMBOL(dasd_reload_device);
606 
607 /*
608  * dasd_restore_device will schedule a call do do_restore_device to the kernel
609  * event daemon.
610  */
611 static void do_restore_device(struct work_struct *work)
612 {
613 	struct dasd_device *device = container_of(work, struct dasd_device,
614 						  restore_device);
615 	device->cdev->drv->restore(device->cdev);
616 	dasd_put_device(device);
617 }
618 
619 void dasd_restore_device(struct dasd_device *device)
620 {
621 	dasd_get_device(device);
622 	/* queue call to dasd_restore_device to the kernel event daemon. */
623 	if (!schedule_work(&device->restore_device))
624 		dasd_put_device(device);
625 }
626 
627 /*
628  * Set the target state for a device and starts the state change.
629  */
630 void dasd_set_target_state(struct dasd_device *device, int target)
631 {
632 	dasd_get_device(device);
633 	mutex_lock(&device->state_mutex);
634 	/* If we are in probeonly mode stop at DASD_STATE_READY. */
635 	if (dasd_probeonly && target > DASD_STATE_READY)
636 		target = DASD_STATE_READY;
637 	if (device->target != target) {
638 		if (device->state == target)
639 			wake_up(&dasd_init_waitq);
640 		device->target = target;
641 	}
642 	if (device->state != device->target)
643 		dasd_change_state(device);
644 	mutex_unlock(&device->state_mutex);
645 	dasd_put_device(device);
646 }
647 EXPORT_SYMBOL(dasd_set_target_state);
648 
649 /*
650  * Enable devices with device numbers in [from..to].
651  */
652 static inline int _wait_for_device(struct dasd_device *device)
653 {
654 	return (device->state == device->target);
655 }
656 
657 void dasd_enable_device(struct dasd_device *device)
658 {
659 	dasd_set_target_state(device, DASD_STATE_ONLINE);
660 	if (device->state <= DASD_STATE_KNOWN)
661 		/* No discipline for device found. */
662 		dasd_set_target_state(device, DASD_STATE_NEW);
663 	/* Now wait for the devices to come up. */
664 	wait_event(dasd_init_waitq, _wait_for_device(device));
665 
666 	dasd_reload_device(device);
667 	if (device->discipline->kick_validate)
668 		device->discipline->kick_validate(device);
669 }
670 EXPORT_SYMBOL(dasd_enable_device);
671 
672 /*
673  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
674  */
675 
676 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
677 
678 #ifdef CONFIG_DASD_PROFILE
679 struct dasd_profile dasd_global_profile = {
680 	.lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
681 };
682 static struct dentry *dasd_debugfs_global_entry;
683 
684 /*
685  * Add profiling information for cqr before execution.
686  */
687 static void dasd_profile_start(struct dasd_block *block,
688 			       struct dasd_ccw_req *cqr,
689 			       struct request *req)
690 {
691 	struct list_head *l;
692 	unsigned int counter;
693 	struct dasd_device *device;
694 
695 	/* count the length of the chanq for statistics */
696 	counter = 0;
697 	if (dasd_global_profile_level || block->profile.data)
698 		list_for_each(l, &block->ccw_queue)
699 			if (++counter >= 31)
700 				break;
701 
702 	spin_lock(&dasd_global_profile.lock);
703 	if (dasd_global_profile.data) {
704 		dasd_global_profile.data->dasd_io_nr_req[counter]++;
705 		if (rq_data_dir(req) == READ)
706 			dasd_global_profile.data->dasd_read_nr_req[counter]++;
707 	}
708 	spin_unlock(&dasd_global_profile.lock);
709 
710 	spin_lock(&block->profile.lock);
711 	if (block->profile.data) {
712 		block->profile.data->dasd_io_nr_req[counter]++;
713 		if (rq_data_dir(req) == READ)
714 			block->profile.data->dasd_read_nr_req[counter]++;
715 	}
716 	spin_unlock(&block->profile.lock);
717 
718 	/*
719 	 * We count the request for the start device, even though it may run on
720 	 * some other device due to error recovery. This way we make sure that
721 	 * we count each request only once.
722 	 */
723 	device = cqr->startdev;
724 	if (device->profile.data) {
725 		counter = 1; /* request is not yet queued on the start device */
726 		list_for_each(l, &device->ccw_queue)
727 			if (++counter >= 31)
728 				break;
729 	}
730 	spin_lock(&device->profile.lock);
731 	if (device->profile.data) {
732 		device->profile.data->dasd_io_nr_req[counter]++;
733 		if (rq_data_dir(req) == READ)
734 			device->profile.data->dasd_read_nr_req[counter]++;
735 	}
736 	spin_unlock(&device->profile.lock);
737 }
738 
739 /*
740  * Add profiling information for cqr after execution.
741  */
742 
743 #define dasd_profile_counter(value, index)			   \
744 {								   \
745 	for (index = 0; index < 31 && value >> (2+index); index++) \
746 		;						   \
747 }
748 
749 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
750 				      int is_alias,
751 				      int is_tpm,
752 				      int is_read,
753 				      long sectors,
754 				      int sectors_ind,
755 				      int tottime_ind,
756 				      int tottimeps_ind,
757 				      int strtime_ind,
758 				      int irqtime_ind,
759 				      int irqtimeps_ind,
760 				      int endtime_ind)
761 {
762 	/* in case of an overflow, reset the whole profile */
763 	if (data->dasd_io_reqs == UINT_MAX) {
764 			memset(data, 0, sizeof(*data));
765 			getnstimeofday(&data->starttod);
766 	}
767 	data->dasd_io_reqs++;
768 	data->dasd_io_sects += sectors;
769 	if (is_alias)
770 		data->dasd_io_alias++;
771 	if (is_tpm)
772 		data->dasd_io_tpm++;
773 
774 	data->dasd_io_secs[sectors_ind]++;
775 	data->dasd_io_times[tottime_ind]++;
776 	data->dasd_io_timps[tottimeps_ind]++;
777 	data->dasd_io_time1[strtime_ind]++;
778 	data->dasd_io_time2[irqtime_ind]++;
779 	data->dasd_io_time2ps[irqtimeps_ind]++;
780 	data->dasd_io_time3[endtime_ind]++;
781 
782 	if (is_read) {
783 		data->dasd_read_reqs++;
784 		data->dasd_read_sects += sectors;
785 		if (is_alias)
786 			data->dasd_read_alias++;
787 		if (is_tpm)
788 			data->dasd_read_tpm++;
789 		data->dasd_read_secs[sectors_ind]++;
790 		data->dasd_read_times[tottime_ind]++;
791 		data->dasd_read_time1[strtime_ind]++;
792 		data->dasd_read_time2[irqtime_ind]++;
793 		data->dasd_read_time3[endtime_ind]++;
794 	}
795 }
796 
797 static void dasd_profile_end(struct dasd_block *block,
798 			     struct dasd_ccw_req *cqr,
799 			     struct request *req)
800 {
801 	unsigned long strtime, irqtime, endtime, tottime;
802 	unsigned long tottimeps, sectors;
803 	struct dasd_device *device;
804 	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
805 	int irqtime_ind, irqtimeps_ind, endtime_ind;
806 	struct dasd_profile_info *data;
807 
808 	device = cqr->startdev;
809 	if (!(dasd_global_profile_level ||
810 	      block->profile.data ||
811 	      device->profile.data))
812 		return;
813 
814 	sectors = blk_rq_sectors(req);
815 	if (!cqr->buildclk || !cqr->startclk ||
816 	    !cqr->stopclk || !cqr->endclk ||
817 	    !sectors)
818 		return;
819 
820 	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
821 	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
822 	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
823 	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
824 	tottimeps = tottime / sectors;
825 
826 	dasd_profile_counter(sectors, sectors_ind);
827 	dasd_profile_counter(tottime, tottime_ind);
828 	dasd_profile_counter(tottimeps, tottimeps_ind);
829 	dasd_profile_counter(strtime, strtime_ind);
830 	dasd_profile_counter(irqtime, irqtime_ind);
831 	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
832 	dasd_profile_counter(endtime, endtime_ind);
833 
834 	spin_lock(&dasd_global_profile.lock);
835 	if (dasd_global_profile.data) {
836 		data = dasd_global_profile.data;
837 		data->dasd_sum_times += tottime;
838 		data->dasd_sum_time_str += strtime;
839 		data->dasd_sum_time_irq += irqtime;
840 		data->dasd_sum_time_end += endtime;
841 		dasd_profile_end_add_data(dasd_global_profile.data,
842 					  cqr->startdev != block->base,
843 					  cqr->cpmode == 1,
844 					  rq_data_dir(req) == READ,
845 					  sectors, sectors_ind, tottime_ind,
846 					  tottimeps_ind, strtime_ind,
847 					  irqtime_ind, irqtimeps_ind,
848 					  endtime_ind);
849 	}
850 	spin_unlock(&dasd_global_profile.lock);
851 
852 	spin_lock(&block->profile.lock);
853 	if (block->profile.data) {
854 		data = block->profile.data;
855 		data->dasd_sum_times += tottime;
856 		data->dasd_sum_time_str += strtime;
857 		data->dasd_sum_time_irq += irqtime;
858 		data->dasd_sum_time_end += endtime;
859 		dasd_profile_end_add_data(block->profile.data,
860 					  cqr->startdev != block->base,
861 					  cqr->cpmode == 1,
862 					  rq_data_dir(req) == READ,
863 					  sectors, sectors_ind, tottime_ind,
864 					  tottimeps_ind, strtime_ind,
865 					  irqtime_ind, irqtimeps_ind,
866 					  endtime_ind);
867 	}
868 	spin_unlock(&block->profile.lock);
869 
870 	spin_lock(&device->profile.lock);
871 	if (device->profile.data) {
872 		data = device->profile.data;
873 		data->dasd_sum_times += tottime;
874 		data->dasd_sum_time_str += strtime;
875 		data->dasd_sum_time_irq += irqtime;
876 		data->dasd_sum_time_end += endtime;
877 		dasd_profile_end_add_data(device->profile.data,
878 					  cqr->startdev != block->base,
879 					  cqr->cpmode == 1,
880 					  rq_data_dir(req) == READ,
881 					  sectors, sectors_ind, tottime_ind,
882 					  tottimeps_ind, strtime_ind,
883 					  irqtime_ind, irqtimeps_ind,
884 					  endtime_ind);
885 	}
886 	spin_unlock(&device->profile.lock);
887 }
888 
889 void dasd_profile_reset(struct dasd_profile *profile)
890 {
891 	struct dasd_profile_info *data;
892 
893 	spin_lock_bh(&profile->lock);
894 	data = profile->data;
895 	if (!data) {
896 		spin_unlock_bh(&profile->lock);
897 		return;
898 	}
899 	memset(data, 0, sizeof(*data));
900 	getnstimeofday(&data->starttod);
901 	spin_unlock_bh(&profile->lock);
902 }
903 
904 int dasd_profile_on(struct dasd_profile *profile)
905 {
906 	struct dasd_profile_info *data;
907 
908 	data = kzalloc(sizeof(*data), GFP_KERNEL);
909 	if (!data)
910 		return -ENOMEM;
911 	spin_lock_bh(&profile->lock);
912 	if (profile->data) {
913 		spin_unlock_bh(&profile->lock);
914 		kfree(data);
915 		return 0;
916 	}
917 	getnstimeofday(&data->starttod);
918 	profile->data = data;
919 	spin_unlock_bh(&profile->lock);
920 	return 0;
921 }
922 
923 void dasd_profile_off(struct dasd_profile *profile)
924 {
925 	spin_lock_bh(&profile->lock);
926 	kfree(profile->data);
927 	profile->data = NULL;
928 	spin_unlock_bh(&profile->lock);
929 }
930 
931 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
932 {
933 	char *buffer;
934 
935 	buffer = vmalloc(user_len + 1);
936 	if (buffer == NULL)
937 		return ERR_PTR(-ENOMEM);
938 	if (copy_from_user(buffer, user_buf, user_len) != 0) {
939 		vfree(buffer);
940 		return ERR_PTR(-EFAULT);
941 	}
942 	/* got the string, now strip linefeed. */
943 	if (buffer[user_len - 1] == '\n')
944 		buffer[user_len - 1] = 0;
945 	else
946 		buffer[user_len] = 0;
947 	return buffer;
948 }
949 
950 static ssize_t dasd_stats_write(struct file *file,
951 				const char __user *user_buf,
952 				size_t user_len, loff_t *pos)
953 {
954 	char *buffer, *str;
955 	int rc;
956 	struct seq_file *m = (struct seq_file *)file->private_data;
957 	struct dasd_profile *prof = m->private;
958 
959 	if (user_len > 65536)
960 		user_len = 65536;
961 	buffer = dasd_get_user_string(user_buf, user_len);
962 	if (IS_ERR(buffer))
963 		return PTR_ERR(buffer);
964 
965 	str = skip_spaces(buffer);
966 	rc = user_len;
967 	if (strncmp(str, "reset", 5) == 0) {
968 		dasd_profile_reset(prof);
969 	} else if (strncmp(str, "on", 2) == 0) {
970 		rc = dasd_profile_on(prof);
971 		if (rc)
972 			goto out;
973 		rc = user_len;
974 		if (prof == &dasd_global_profile) {
975 			dasd_profile_reset(prof);
976 			dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
977 		}
978 	} else if (strncmp(str, "off", 3) == 0) {
979 		if (prof == &dasd_global_profile)
980 			dasd_global_profile_level = DASD_PROFILE_OFF;
981 		dasd_profile_off(prof);
982 	} else
983 		rc = -EINVAL;
984 out:
985 	vfree(buffer);
986 	return rc;
987 }
988 
989 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
990 {
991 	int i;
992 
993 	for (i = 0; i < 32; i++)
994 		seq_printf(m, "%u ", array[i]);
995 	seq_putc(m, '\n');
996 }
997 
998 static void dasd_stats_seq_print(struct seq_file *m,
999 				 struct dasd_profile_info *data)
1000 {
1001 	seq_printf(m, "start_time %ld.%09ld\n",
1002 		   data->starttod.tv_sec, data->starttod.tv_nsec);
1003 	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1004 	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1005 	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1006 	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1007 	seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1008 		   data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1009 	seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1010 		   data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1011 	seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1012 		   data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1013 	seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1014 		   data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1015 	seq_puts(m, "histogram_sectors ");
1016 	dasd_stats_array(m, data->dasd_io_secs);
1017 	seq_puts(m, "histogram_io_times ");
1018 	dasd_stats_array(m, data->dasd_io_times);
1019 	seq_puts(m, "histogram_io_times_weighted ");
1020 	dasd_stats_array(m, data->dasd_io_timps);
1021 	seq_puts(m, "histogram_time_build_to_ssch ");
1022 	dasd_stats_array(m, data->dasd_io_time1);
1023 	seq_puts(m, "histogram_time_ssch_to_irq ");
1024 	dasd_stats_array(m, data->dasd_io_time2);
1025 	seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1026 	dasd_stats_array(m, data->dasd_io_time2ps);
1027 	seq_puts(m, "histogram_time_irq_to_end ");
1028 	dasd_stats_array(m, data->dasd_io_time3);
1029 	seq_puts(m, "histogram_ccw_queue_length ");
1030 	dasd_stats_array(m, data->dasd_io_nr_req);
1031 	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1032 	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1033 	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1034 	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1035 	seq_puts(m, "histogram_read_sectors ");
1036 	dasd_stats_array(m, data->dasd_read_secs);
1037 	seq_puts(m, "histogram_read_times ");
1038 	dasd_stats_array(m, data->dasd_read_times);
1039 	seq_puts(m, "histogram_read_time_build_to_ssch ");
1040 	dasd_stats_array(m, data->dasd_read_time1);
1041 	seq_puts(m, "histogram_read_time_ssch_to_irq ");
1042 	dasd_stats_array(m, data->dasd_read_time2);
1043 	seq_puts(m, "histogram_read_time_irq_to_end ");
1044 	dasd_stats_array(m, data->dasd_read_time3);
1045 	seq_puts(m, "histogram_read_ccw_queue_length ");
1046 	dasd_stats_array(m, data->dasd_read_nr_req);
1047 }
1048 
1049 static int dasd_stats_show(struct seq_file *m, void *v)
1050 {
1051 	struct dasd_profile *profile;
1052 	struct dasd_profile_info *data;
1053 
1054 	profile = m->private;
1055 	spin_lock_bh(&profile->lock);
1056 	data = profile->data;
1057 	if (!data) {
1058 		spin_unlock_bh(&profile->lock);
1059 		seq_puts(m, "disabled\n");
1060 		return 0;
1061 	}
1062 	dasd_stats_seq_print(m, data);
1063 	spin_unlock_bh(&profile->lock);
1064 	return 0;
1065 }
1066 
1067 static int dasd_stats_open(struct inode *inode, struct file *file)
1068 {
1069 	struct dasd_profile *profile = inode->i_private;
1070 	return single_open(file, dasd_stats_show, profile);
1071 }
1072 
1073 static const struct file_operations dasd_stats_raw_fops = {
1074 	.owner		= THIS_MODULE,
1075 	.open		= dasd_stats_open,
1076 	.read		= seq_read,
1077 	.llseek		= seq_lseek,
1078 	.release	= single_release,
1079 	.write		= dasd_stats_write,
1080 };
1081 
1082 static void dasd_profile_init(struct dasd_profile *profile,
1083 			      struct dentry *base_dentry)
1084 {
1085 	umode_t mode;
1086 	struct dentry *pde;
1087 
1088 	if (!base_dentry)
1089 		return;
1090 	profile->dentry = NULL;
1091 	profile->data = NULL;
1092 	mode = (S_IRUSR | S_IWUSR | S_IFREG);
1093 	pde = debugfs_create_file("statistics", mode, base_dentry,
1094 				  profile, &dasd_stats_raw_fops);
1095 	if (pde && !IS_ERR(pde))
1096 		profile->dentry = pde;
1097 	return;
1098 }
1099 
1100 static void dasd_profile_exit(struct dasd_profile *profile)
1101 {
1102 	dasd_profile_off(profile);
1103 	debugfs_remove(profile->dentry);
1104 	profile->dentry = NULL;
1105 }
1106 
1107 static void dasd_statistics_removeroot(void)
1108 {
1109 	dasd_global_profile_level = DASD_PROFILE_OFF;
1110 	dasd_profile_exit(&dasd_global_profile);
1111 	debugfs_remove(dasd_debugfs_global_entry);
1112 	debugfs_remove(dasd_debugfs_root_entry);
1113 }
1114 
1115 static void dasd_statistics_createroot(void)
1116 {
1117 	struct dentry *pde;
1118 
1119 	dasd_debugfs_root_entry = NULL;
1120 	pde = debugfs_create_dir("dasd", NULL);
1121 	if (!pde || IS_ERR(pde))
1122 		goto error;
1123 	dasd_debugfs_root_entry = pde;
1124 	pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1125 	if (!pde || IS_ERR(pde))
1126 		goto error;
1127 	dasd_debugfs_global_entry = pde;
1128 	dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1129 	return;
1130 
1131 error:
1132 	DBF_EVENT(DBF_ERR, "%s",
1133 		  "Creation of the dasd debugfs interface failed");
1134 	dasd_statistics_removeroot();
1135 	return;
1136 }
1137 
1138 #else
1139 #define dasd_profile_start(block, cqr, req) do {} while (0)
1140 #define dasd_profile_end(block, cqr, req) do {} while (0)
1141 
1142 static void dasd_statistics_createroot(void)
1143 {
1144 	return;
1145 }
1146 
1147 static void dasd_statistics_removeroot(void)
1148 {
1149 	return;
1150 }
1151 
1152 int dasd_stats_generic_show(struct seq_file *m, void *v)
1153 {
1154 	seq_puts(m, "Statistics are not activated in this kernel\n");
1155 	return 0;
1156 }
1157 
1158 static void dasd_profile_init(struct dasd_profile *profile,
1159 			      struct dentry *base_dentry)
1160 {
1161 	return;
1162 }
1163 
1164 static void dasd_profile_exit(struct dasd_profile *profile)
1165 {
1166 	return;
1167 }
1168 
1169 int dasd_profile_on(struct dasd_profile *profile)
1170 {
1171 	return 0;
1172 }
1173 
1174 #endif				/* CONFIG_DASD_PROFILE */
1175 
1176 static int dasd_hosts_show(struct seq_file *m, void *v)
1177 {
1178 	struct dasd_device *device;
1179 	int rc = -EOPNOTSUPP;
1180 
1181 	device = m->private;
1182 	dasd_get_device(device);
1183 
1184 	if (device->discipline->hosts_print)
1185 		rc = device->discipline->hosts_print(device, m);
1186 
1187 	dasd_put_device(device);
1188 	return rc;
1189 }
1190 
1191 static int dasd_hosts_open(struct inode *inode, struct file *file)
1192 {
1193 	struct dasd_device *device = inode->i_private;
1194 
1195 	return single_open(file, dasd_hosts_show, device);
1196 }
1197 
1198 static const struct file_operations dasd_hosts_fops = {
1199 	.owner		= THIS_MODULE,
1200 	.open		= dasd_hosts_open,
1201 	.read		= seq_read,
1202 	.llseek		= seq_lseek,
1203 	.release	= single_release,
1204 };
1205 
1206 static void dasd_hosts_exit(struct dasd_device *device)
1207 {
1208 	debugfs_remove(device->hosts_dentry);
1209 	device->hosts_dentry = NULL;
1210 }
1211 
1212 static void dasd_hosts_init(struct dentry *base_dentry,
1213 			    struct dasd_device *device)
1214 {
1215 	struct dentry *pde;
1216 	umode_t mode;
1217 
1218 	if (!base_dentry)
1219 		return;
1220 
1221 	mode = S_IRUSR | S_IFREG;
1222 	pde = debugfs_create_file("host_access_list", mode, base_dentry,
1223 				  device, &dasd_hosts_fops);
1224 	if (pde && !IS_ERR(pde))
1225 		device->hosts_dentry = pde;
1226 }
1227 
1228 /*
1229  * Allocate memory for a channel program with 'cplength' channel
1230  * command words and 'datasize' additional space. There are two
1231  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1232  * memory and 2) dasd_smalloc_request uses the static ccw memory
1233  * that gets allocated for each device.
1234  */
1235 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1236 					  int datasize,
1237 					  struct dasd_device *device)
1238 {
1239 	struct dasd_ccw_req *cqr;
1240 
1241 	/* Sanity checks */
1242 	BUG_ON(datasize > PAGE_SIZE ||
1243 	     (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1244 
1245 	cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1246 	if (cqr == NULL)
1247 		return ERR_PTR(-ENOMEM);
1248 	cqr->cpaddr = NULL;
1249 	if (cplength > 0) {
1250 		cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1251 				      GFP_ATOMIC | GFP_DMA);
1252 		if (cqr->cpaddr == NULL) {
1253 			kfree(cqr);
1254 			return ERR_PTR(-ENOMEM);
1255 		}
1256 	}
1257 	cqr->data = NULL;
1258 	if (datasize > 0) {
1259 		cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1260 		if (cqr->data == NULL) {
1261 			kfree(cqr->cpaddr);
1262 			kfree(cqr);
1263 			return ERR_PTR(-ENOMEM);
1264 		}
1265 	}
1266 	cqr->magic =  magic;
1267 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1268 	dasd_get_device(device);
1269 	return cqr;
1270 }
1271 EXPORT_SYMBOL(dasd_kmalloc_request);
1272 
1273 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1274 					  int datasize,
1275 					  struct dasd_device *device)
1276 {
1277 	unsigned long flags;
1278 	struct dasd_ccw_req *cqr;
1279 	char *data;
1280 	int size;
1281 
1282 	size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1283 	if (cplength > 0)
1284 		size += cplength * sizeof(struct ccw1);
1285 	if (datasize > 0)
1286 		size += datasize;
1287 	spin_lock_irqsave(&device->mem_lock, flags);
1288 	cqr = (struct dasd_ccw_req *)
1289 		dasd_alloc_chunk(&device->ccw_chunks, size);
1290 	spin_unlock_irqrestore(&device->mem_lock, flags);
1291 	if (cqr == NULL)
1292 		return ERR_PTR(-ENOMEM);
1293 	memset(cqr, 0, sizeof(struct dasd_ccw_req));
1294 	data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1295 	cqr->cpaddr = NULL;
1296 	if (cplength > 0) {
1297 		cqr->cpaddr = (struct ccw1 *) data;
1298 		data += cplength*sizeof(struct ccw1);
1299 		memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1300 	}
1301 	cqr->data = NULL;
1302 	if (datasize > 0) {
1303 		cqr->data = data;
1304  		memset(cqr->data, 0, datasize);
1305 	}
1306 	cqr->magic = magic;
1307 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1308 	dasd_get_device(device);
1309 	return cqr;
1310 }
1311 EXPORT_SYMBOL(dasd_smalloc_request);
1312 
1313 /*
1314  * Free memory of a channel program. This function needs to free all the
1315  * idal lists that might have been created by dasd_set_cda and the
1316  * struct dasd_ccw_req itself.
1317  */
1318 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1319 {
1320 	struct ccw1 *ccw;
1321 
1322 	/* Clear any idals used for the request. */
1323 	ccw = cqr->cpaddr;
1324 	do {
1325 		clear_normalized_cda(ccw);
1326 	} while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1327 	kfree(cqr->cpaddr);
1328 	kfree(cqr->data);
1329 	kfree(cqr);
1330 	dasd_put_device(device);
1331 }
1332 EXPORT_SYMBOL(dasd_kfree_request);
1333 
1334 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1335 {
1336 	unsigned long flags;
1337 
1338 	spin_lock_irqsave(&device->mem_lock, flags);
1339 	dasd_free_chunk(&device->ccw_chunks, cqr);
1340 	spin_unlock_irqrestore(&device->mem_lock, flags);
1341 	dasd_put_device(device);
1342 }
1343 EXPORT_SYMBOL(dasd_sfree_request);
1344 
1345 /*
1346  * Check discipline magic in cqr.
1347  */
1348 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1349 {
1350 	struct dasd_device *device;
1351 
1352 	if (cqr == NULL)
1353 		return -EINVAL;
1354 	device = cqr->startdev;
1355 	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1356 		DBF_DEV_EVENT(DBF_WARNING, device,
1357 			    " dasd_ccw_req 0x%08x magic doesn't match"
1358 			    " discipline 0x%08x",
1359 			    cqr->magic,
1360 			    *(unsigned int *) device->discipline->name);
1361 		return -EINVAL;
1362 	}
1363 	return 0;
1364 }
1365 
1366 /*
1367  * Terminate the current i/o and set the request to clear_pending.
1368  * Timer keeps device runnig.
1369  * ccw_device_clear can fail if the i/o subsystem
1370  * is in a bad mood.
1371  */
1372 int dasd_term_IO(struct dasd_ccw_req *cqr)
1373 {
1374 	struct dasd_device *device;
1375 	int retries, rc;
1376 	char errorstring[ERRORLENGTH];
1377 
1378 	/* Check the cqr */
1379 	rc = dasd_check_cqr(cqr);
1380 	if (rc)
1381 		return rc;
1382 	retries = 0;
1383 	device = (struct dasd_device *) cqr->startdev;
1384 	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1385 		rc = ccw_device_clear(device->cdev, (long) cqr);
1386 		switch (rc) {
1387 		case 0:	/* termination successful */
1388 			cqr->status = DASD_CQR_CLEAR_PENDING;
1389 			cqr->stopclk = get_tod_clock();
1390 			cqr->starttime = 0;
1391 			DBF_DEV_EVENT(DBF_DEBUG, device,
1392 				      "terminate cqr %p successful",
1393 				      cqr);
1394 			break;
1395 		case -ENODEV:
1396 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1397 				      "device gone, retry");
1398 			break;
1399 		case -EIO:
1400 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1401 				      "I/O error, retry");
1402 			break;
1403 		case -EINVAL:
1404 			/*
1405 			 * device not valid so no I/O could be running
1406 			 * handle CQR as termination successful
1407 			 */
1408 			cqr->status = DASD_CQR_CLEARED;
1409 			cqr->stopclk = get_tod_clock();
1410 			cqr->starttime = 0;
1411 			/* no retries for invalid devices */
1412 			cqr->retries = -1;
1413 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1414 				      "EINVAL, handle as terminated");
1415 			/* fake rc to success */
1416 			rc = 0;
1417 			break;
1418 		case -EBUSY:
1419 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1420 				      "device busy, retry later");
1421 			break;
1422 		default:
1423 			/* internal error 10 - unknown rc*/
1424 			snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1425 			dev_err(&device->cdev->dev, "An error occurred in the "
1426 				"DASD device driver, reason=%s\n", errorstring);
1427 			BUG();
1428 			break;
1429 		}
1430 		retries++;
1431 	}
1432 	dasd_schedule_device_bh(device);
1433 	return rc;
1434 }
1435 EXPORT_SYMBOL(dasd_term_IO);
1436 
1437 /*
1438  * Start the i/o. This start_IO can fail if the channel is really busy.
1439  * In that case set up a timer to start the request later.
1440  */
1441 int dasd_start_IO(struct dasd_ccw_req *cqr)
1442 {
1443 	struct dasd_device *device;
1444 	int rc;
1445 	char errorstring[ERRORLENGTH];
1446 
1447 	/* Check the cqr */
1448 	rc = dasd_check_cqr(cqr);
1449 	if (rc) {
1450 		cqr->intrc = rc;
1451 		return rc;
1452 	}
1453 	device = (struct dasd_device *) cqr->startdev;
1454 	if (((cqr->block &&
1455 	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1456 	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1457 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1458 		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1459 			      "because of stolen lock", cqr);
1460 		cqr->status = DASD_CQR_ERROR;
1461 		cqr->intrc = -EPERM;
1462 		return -EPERM;
1463 	}
1464 	if (cqr->retries < 0) {
1465 		/* internal error 14 - start_IO run out of retries */
1466 		sprintf(errorstring, "14 %p", cqr);
1467 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1468 			"device driver, reason=%s\n", errorstring);
1469 		cqr->status = DASD_CQR_ERROR;
1470 		return -EIO;
1471 	}
1472 	cqr->startclk = get_tod_clock();
1473 	cqr->starttime = jiffies;
1474 	cqr->retries--;
1475 	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1476 		cqr->lpm &= dasd_path_get_opm(device);
1477 		if (!cqr->lpm)
1478 			cqr->lpm = dasd_path_get_opm(device);
1479 	}
1480 	if (cqr->cpmode == 1) {
1481 		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1482 					 (long) cqr, cqr->lpm);
1483 	} else {
1484 		rc = ccw_device_start(device->cdev, cqr->cpaddr,
1485 				      (long) cqr, cqr->lpm, 0);
1486 	}
1487 	switch (rc) {
1488 	case 0:
1489 		cqr->status = DASD_CQR_IN_IO;
1490 		break;
1491 	case -EBUSY:
1492 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1493 			      "start_IO: device busy, retry later");
1494 		break;
1495 	case -ETIMEDOUT:
1496 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1497 			      "start_IO: request timeout, retry later");
1498 		break;
1499 	case -EACCES:
1500 		/* -EACCES indicates that the request used only a subset of the
1501 		 * available paths and all these paths are gone. If the lpm of
1502 		 * this request was only a subset of the opm (e.g. the ppm) then
1503 		 * we just do a retry with all available paths.
1504 		 * If we already use the full opm, something is amiss, and we
1505 		 * need a full path verification.
1506 		 */
1507 		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1508 			DBF_DEV_EVENT(DBF_WARNING, device,
1509 				      "start_IO: selected paths gone (%x)",
1510 				      cqr->lpm);
1511 		} else if (cqr->lpm != dasd_path_get_opm(device)) {
1512 			cqr->lpm = dasd_path_get_opm(device);
1513 			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1514 				      "start_IO: selected paths gone,"
1515 				      " retry on all paths");
1516 		} else {
1517 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1518 				      "start_IO: all paths in opm gone,"
1519 				      " do path verification");
1520 			dasd_generic_last_path_gone(device);
1521 			dasd_path_no_path(device);
1522 			dasd_path_set_tbvpm(device,
1523 					  ccw_device_get_path_mask(
1524 						  device->cdev));
1525 		}
1526 		break;
1527 	case -ENODEV:
1528 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1529 			      "start_IO: -ENODEV device gone, retry");
1530 		break;
1531 	case -EIO:
1532 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1533 			      "start_IO: -EIO device gone, retry");
1534 		break;
1535 	case -EINVAL:
1536 		/* most likely caused in power management context */
1537 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1538 			      "start_IO: -EINVAL device currently "
1539 			      "not accessible");
1540 		break;
1541 	default:
1542 		/* internal error 11 - unknown rc */
1543 		snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1544 		dev_err(&device->cdev->dev,
1545 			"An error occurred in the DASD device driver, "
1546 			"reason=%s\n", errorstring);
1547 		BUG();
1548 		break;
1549 	}
1550 	cqr->intrc = rc;
1551 	return rc;
1552 }
1553 EXPORT_SYMBOL(dasd_start_IO);
1554 
1555 /*
1556  * Timeout function for dasd devices. This is used for different purposes
1557  *  1) missing interrupt handler for normal operation
1558  *  2) delayed start of request where start_IO failed with -EBUSY
1559  *  3) timeout for missing state change interrupts
1560  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1561  * DASD_CQR_QUEUED for 2) and 3).
1562  */
1563 static void dasd_device_timeout(unsigned long ptr)
1564 {
1565 	unsigned long flags;
1566 	struct dasd_device *device;
1567 
1568 	device = (struct dasd_device *) ptr;
1569 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1570 	/* re-activate request queue */
1571 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1572 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1573 	dasd_schedule_device_bh(device);
1574 }
1575 
1576 /*
1577  * Setup timeout for a device in jiffies.
1578  */
1579 void dasd_device_set_timer(struct dasd_device *device, int expires)
1580 {
1581 	if (expires == 0)
1582 		del_timer(&device->timer);
1583 	else
1584 		mod_timer(&device->timer, jiffies + expires);
1585 }
1586 EXPORT_SYMBOL(dasd_device_set_timer);
1587 
1588 /*
1589  * Clear timeout for a device.
1590  */
1591 void dasd_device_clear_timer(struct dasd_device *device)
1592 {
1593 	del_timer(&device->timer);
1594 }
1595 EXPORT_SYMBOL(dasd_device_clear_timer);
1596 
1597 static void dasd_handle_killed_request(struct ccw_device *cdev,
1598 				       unsigned long intparm)
1599 {
1600 	struct dasd_ccw_req *cqr;
1601 	struct dasd_device *device;
1602 
1603 	if (!intparm)
1604 		return;
1605 	cqr = (struct dasd_ccw_req *) intparm;
1606 	if (cqr->status != DASD_CQR_IN_IO) {
1607 		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1608 				"invalid status in handle_killed_request: "
1609 				"%02x", cqr->status);
1610 		return;
1611 	}
1612 
1613 	device = dasd_device_from_cdev_locked(cdev);
1614 	if (IS_ERR(device)) {
1615 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1616 				"unable to get device from cdev");
1617 		return;
1618 	}
1619 
1620 	if (!cqr->startdev ||
1621 	    device != cqr->startdev ||
1622 	    strncmp(cqr->startdev->discipline->ebcname,
1623 		    (char *) &cqr->magic, 4)) {
1624 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1625 				"invalid device in request");
1626 		dasd_put_device(device);
1627 		return;
1628 	}
1629 
1630 	/* Schedule request to be retried. */
1631 	cqr->status = DASD_CQR_QUEUED;
1632 
1633 	dasd_device_clear_timer(device);
1634 	dasd_schedule_device_bh(device);
1635 	dasd_put_device(device);
1636 }
1637 
1638 void dasd_generic_handle_state_change(struct dasd_device *device)
1639 {
1640 	/* First of all start sense subsystem status request. */
1641 	dasd_eer_snss(device);
1642 
1643 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1644 	dasd_schedule_device_bh(device);
1645 	if (device->block) {
1646 		dasd_schedule_block_bh(device->block);
1647 		if (device->block->request_queue)
1648 			blk_mq_run_hw_queues(device->block->request_queue,
1649 					     true);
1650 	}
1651 }
1652 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1653 
1654 static int dasd_check_hpf_error(struct irb *irb)
1655 {
1656 	return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1657 	    (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1658 	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1659 }
1660 
1661 /*
1662  * Interrupt handler for "normal" ssch-io based dasd devices.
1663  */
1664 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1665 		      struct irb *irb)
1666 {
1667 	struct dasd_ccw_req *cqr, *next;
1668 	struct dasd_device *device;
1669 	unsigned long now;
1670 	int nrf_suppressed = 0;
1671 	int fp_suppressed = 0;
1672 	u8 *sense = NULL;
1673 	int expires;
1674 
1675 	cqr = (struct dasd_ccw_req *) intparm;
1676 	if (IS_ERR(irb)) {
1677 		switch (PTR_ERR(irb)) {
1678 		case -EIO:
1679 			if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1680 				device = cqr->startdev;
1681 				cqr->status = DASD_CQR_CLEARED;
1682 				dasd_device_clear_timer(device);
1683 				wake_up(&dasd_flush_wq);
1684 				dasd_schedule_device_bh(device);
1685 				return;
1686 			}
1687 			break;
1688 		case -ETIMEDOUT:
1689 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1690 					"request timed out\n", __func__);
1691 			break;
1692 		default:
1693 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1694 					"unknown error %ld\n", __func__,
1695 					PTR_ERR(irb));
1696 		}
1697 		dasd_handle_killed_request(cdev, intparm);
1698 		return;
1699 	}
1700 
1701 	now = get_tod_clock();
1702 	/* check for conditions that should be handled immediately */
1703 	if (!cqr ||
1704 	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1705 	      scsw_cstat(&irb->scsw) == 0)) {
1706 		if (cqr)
1707 			memcpy(&cqr->irb, irb, sizeof(*irb));
1708 		device = dasd_device_from_cdev_locked(cdev);
1709 		if (IS_ERR(device))
1710 			return;
1711 		/* ignore unsolicited interrupts for DIAG discipline */
1712 		if (device->discipline == dasd_diag_discipline_pointer) {
1713 			dasd_put_device(device);
1714 			return;
1715 		}
1716 
1717 		/*
1718 		 * In some cases 'File Protected' or 'No Record Found' errors
1719 		 * might be expected and debug log messages for the
1720 		 * corresponding interrupts shouldn't be written then.
1721 		 * Check if either of the according suppress bits is set.
1722 		 */
1723 		sense = dasd_get_sense(irb);
1724 		if (sense) {
1725 			fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1726 				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1727 			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1728 				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1729 		}
1730 		if (!(fp_suppressed || nrf_suppressed))
1731 			device->discipline->dump_sense_dbf(device, irb, "int");
1732 
1733 		if (device->features & DASD_FEATURE_ERPLOG)
1734 			device->discipline->dump_sense(device, cqr, irb);
1735 		device->discipline->check_for_device_change(device, cqr, irb);
1736 		dasd_put_device(device);
1737 	}
1738 
1739 	/* check for for attention message */
1740 	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1741 		device = dasd_device_from_cdev_locked(cdev);
1742 		if (!IS_ERR(device)) {
1743 			device->discipline->check_attention(device,
1744 							    irb->esw.esw1.lpum);
1745 			dasd_put_device(device);
1746 		}
1747 	}
1748 
1749 	if (!cqr)
1750 		return;
1751 
1752 	device = (struct dasd_device *) cqr->startdev;
1753 	if (!device ||
1754 	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1755 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1756 				"invalid device in request");
1757 		return;
1758 	}
1759 
1760 	/* Check for clear pending */
1761 	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1762 	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1763 		cqr->status = DASD_CQR_CLEARED;
1764 		dasd_device_clear_timer(device);
1765 		wake_up(&dasd_flush_wq);
1766 		dasd_schedule_device_bh(device);
1767 		return;
1768 	}
1769 
1770 	/* check status - the request might have been killed by dyn detach */
1771 	if (cqr->status != DASD_CQR_IN_IO) {
1772 		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1773 			      "status %02x", dev_name(&cdev->dev), cqr->status);
1774 		return;
1775 	}
1776 
1777 	next = NULL;
1778 	expires = 0;
1779 	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1780 	    scsw_cstat(&irb->scsw) == 0) {
1781 		/* request was completed successfully */
1782 		cqr->status = DASD_CQR_SUCCESS;
1783 		cqr->stopclk = now;
1784 		/* Start first request on queue if possible -> fast_io. */
1785 		if (cqr->devlist.next != &device->ccw_queue) {
1786 			next = list_entry(cqr->devlist.next,
1787 					  struct dasd_ccw_req, devlist);
1788 		}
1789 	} else {  /* error */
1790 		/* check for HPF error
1791 		 * call discipline function to requeue all requests
1792 		 * and disable HPF accordingly
1793 		 */
1794 		if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1795 		    device->discipline->handle_hpf_error)
1796 			device->discipline->handle_hpf_error(device, irb);
1797 		/*
1798 		 * If we don't want complex ERP for this request, then just
1799 		 * reset this and retry it in the fastpath
1800 		 */
1801 		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1802 		    cqr->retries > 0) {
1803 			if (cqr->lpm == dasd_path_get_opm(device))
1804 				DBF_DEV_EVENT(DBF_DEBUG, device,
1805 					      "default ERP in fastpath "
1806 					      "(%i retries left)",
1807 					      cqr->retries);
1808 			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1809 				cqr->lpm = dasd_path_get_opm(device);
1810 			cqr->status = DASD_CQR_QUEUED;
1811 			next = cqr;
1812 		} else
1813 			cqr->status = DASD_CQR_ERROR;
1814 	}
1815 	if (next && (next->status == DASD_CQR_QUEUED) &&
1816 	    (!device->stopped)) {
1817 		if (device->discipline->start_IO(next) == 0)
1818 			expires = next->expires;
1819 	}
1820 	if (expires != 0)
1821 		dasd_device_set_timer(device, expires);
1822 	else
1823 		dasd_device_clear_timer(device);
1824 	dasd_schedule_device_bh(device);
1825 }
1826 EXPORT_SYMBOL(dasd_int_handler);
1827 
1828 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1829 {
1830 	struct dasd_device *device;
1831 
1832 	device = dasd_device_from_cdev_locked(cdev);
1833 
1834 	if (IS_ERR(device))
1835 		goto out;
1836 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1837 	   device->state != device->target ||
1838 	   !device->discipline->check_for_device_change){
1839 		dasd_put_device(device);
1840 		goto out;
1841 	}
1842 	if (device->discipline->dump_sense_dbf)
1843 		device->discipline->dump_sense_dbf(device, irb, "uc");
1844 	device->discipline->check_for_device_change(device, NULL, irb);
1845 	dasd_put_device(device);
1846 out:
1847 	return UC_TODO_RETRY;
1848 }
1849 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1850 
1851 /*
1852  * If we have an error on a dasd_block layer request then we cancel
1853  * and return all further requests from the same dasd_block as well.
1854  */
1855 static void __dasd_device_recovery(struct dasd_device *device,
1856 				   struct dasd_ccw_req *ref_cqr)
1857 {
1858 	struct list_head *l, *n;
1859 	struct dasd_ccw_req *cqr;
1860 
1861 	/*
1862 	 * only requeue request that came from the dasd_block layer
1863 	 */
1864 	if (!ref_cqr->block)
1865 		return;
1866 
1867 	list_for_each_safe(l, n, &device->ccw_queue) {
1868 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1869 		if (cqr->status == DASD_CQR_QUEUED &&
1870 		    ref_cqr->block == cqr->block) {
1871 			cqr->status = DASD_CQR_CLEARED;
1872 		}
1873 	}
1874 };
1875 
1876 /*
1877  * Remove those ccw requests from the queue that need to be returned
1878  * to the upper layer.
1879  */
1880 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1881 					    struct list_head *final_queue)
1882 {
1883 	struct list_head *l, *n;
1884 	struct dasd_ccw_req *cqr;
1885 
1886 	/* Process request with final status. */
1887 	list_for_each_safe(l, n, &device->ccw_queue) {
1888 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1889 
1890 		/* Skip any non-final request. */
1891 		if (cqr->status == DASD_CQR_QUEUED ||
1892 		    cqr->status == DASD_CQR_IN_IO ||
1893 		    cqr->status == DASD_CQR_CLEAR_PENDING)
1894 			continue;
1895 		if (cqr->status == DASD_CQR_ERROR) {
1896 			__dasd_device_recovery(device, cqr);
1897 		}
1898 		/* Rechain finished requests to final queue */
1899 		list_move_tail(&cqr->devlist, final_queue);
1900 	}
1901 }
1902 
1903 /*
1904  * the cqrs from the final queue are returned to the upper layer
1905  * by setting a dasd_block state and calling the callback function
1906  */
1907 static void __dasd_device_process_final_queue(struct dasd_device *device,
1908 					      struct list_head *final_queue)
1909 {
1910 	struct list_head *l, *n;
1911 	struct dasd_ccw_req *cqr;
1912 	struct dasd_block *block;
1913 	void (*callback)(struct dasd_ccw_req *, void *data);
1914 	void *callback_data;
1915 	char errorstring[ERRORLENGTH];
1916 
1917 	list_for_each_safe(l, n, final_queue) {
1918 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1919 		list_del_init(&cqr->devlist);
1920 		block = cqr->block;
1921 		callback = cqr->callback;
1922 		callback_data = cqr->callback_data;
1923 		if (block)
1924 			spin_lock_bh(&block->queue_lock);
1925 		switch (cqr->status) {
1926 		case DASD_CQR_SUCCESS:
1927 			cqr->status = DASD_CQR_DONE;
1928 			break;
1929 		case DASD_CQR_ERROR:
1930 			cqr->status = DASD_CQR_NEED_ERP;
1931 			break;
1932 		case DASD_CQR_CLEARED:
1933 			cqr->status = DASD_CQR_TERMINATED;
1934 			break;
1935 		default:
1936 			/* internal error 12 - wrong cqr status*/
1937 			snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1938 			dev_err(&device->cdev->dev,
1939 				"An error occurred in the DASD device driver, "
1940 				"reason=%s\n", errorstring);
1941 			BUG();
1942 		}
1943 		if (cqr->callback != NULL)
1944 			(callback)(cqr, callback_data);
1945 		if (block)
1946 			spin_unlock_bh(&block->queue_lock);
1947 	}
1948 }
1949 
1950 /*
1951  * Take a look at the first request on the ccw queue and check
1952  * if it reached its expire time. If so, terminate the IO.
1953  */
1954 static void __dasd_device_check_expire(struct dasd_device *device)
1955 {
1956 	struct dasd_ccw_req *cqr;
1957 
1958 	if (list_empty(&device->ccw_queue))
1959 		return;
1960 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1961 	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1962 	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1963 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1964 			/*
1965 			 * IO in safe offline processing should not
1966 			 * run out of retries
1967 			 */
1968 			cqr->retries++;
1969 		}
1970 		if (device->discipline->term_IO(cqr) != 0) {
1971 			/* Hmpf, try again in 5 sec */
1972 			dev_err(&device->cdev->dev,
1973 				"cqr %p timed out (%lus) but cannot be "
1974 				"ended, retrying in 5 s\n",
1975 				cqr, (cqr->expires/HZ));
1976 			cqr->expires += 5*HZ;
1977 			dasd_device_set_timer(device, 5*HZ);
1978 		} else {
1979 			dev_err(&device->cdev->dev,
1980 				"cqr %p timed out (%lus), %i retries "
1981 				"remaining\n", cqr, (cqr->expires/HZ),
1982 				cqr->retries);
1983 		}
1984 	}
1985 }
1986 
1987 /*
1988  * return 1 when device is not eligible for IO
1989  */
1990 static int __dasd_device_is_unusable(struct dasd_device *device,
1991 				     struct dasd_ccw_req *cqr)
1992 {
1993 	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1994 
1995 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
1996 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1997 		/*
1998 		 * dasd is being set offline
1999 		 * but it is no safe offline where we have to allow I/O
2000 		 */
2001 		return 1;
2002 	}
2003 	if (device->stopped) {
2004 		if (device->stopped & mask) {
2005 			/* stopped and CQR will not change that. */
2006 			return 1;
2007 		}
2008 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2009 			/* CQR is not able to change device to
2010 			 * operational. */
2011 			return 1;
2012 		}
2013 		/* CQR required to get device operational. */
2014 	}
2015 	return 0;
2016 }
2017 
2018 /*
2019  * Take a look at the first request on the ccw queue and check
2020  * if it needs to be started.
2021  */
2022 static void __dasd_device_start_head(struct dasd_device *device)
2023 {
2024 	struct dasd_ccw_req *cqr;
2025 	int rc;
2026 
2027 	if (list_empty(&device->ccw_queue))
2028 		return;
2029 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2030 	if (cqr->status != DASD_CQR_QUEUED)
2031 		return;
2032 	/* if device is not usable return request to upper layer */
2033 	if (__dasd_device_is_unusable(device, cqr)) {
2034 		cqr->intrc = -EAGAIN;
2035 		cqr->status = DASD_CQR_CLEARED;
2036 		dasd_schedule_device_bh(device);
2037 		return;
2038 	}
2039 
2040 	rc = device->discipline->start_IO(cqr);
2041 	if (rc == 0)
2042 		dasd_device_set_timer(device, cqr->expires);
2043 	else if (rc == -EACCES) {
2044 		dasd_schedule_device_bh(device);
2045 	} else
2046 		/* Hmpf, try again in 1/2 sec */
2047 		dasd_device_set_timer(device, 50);
2048 }
2049 
2050 static void __dasd_device_check_path_events(struct dasd_device *device)
2051 {
2052 	int rc;
2053 
2054 	if (!dasd_path_get_tbvpm(device))
2055 		return;
2056 
2057 	if (device->stopped &
2058 	    ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2059 		return;
2060 	rc = device->discipline->verify_path(device,
2061 					     dasd_path_get_tbvpm(device));
2062 	if (rc)
2063 		dasd_device_set_timer(device, 50);
2064 	else
2065 		dasd_path_clear_all_verify(device);
2066 };
2067 
2068 /*
2069  * Go through all request on the dasd_device request queue,
2070  * terminate them on the cdev if necessary, and return them to the
2071  * submitting layer via callback.
2072  * Note:
2073  * Make sure that all 'submitting layers' still exist when
2074  * this function is called!. In other words, when 'device' is a base
2075  * device then all block layer requests must have been removed before
2076  * via dasd_flush_block_queue.
2077  */
2078 int dasd_flush_device_queue(struct dasd_device *device)
2079 {
2080 	struct dasd_ccw_req *cqr, *n;
2081 	int rc;
2082 	struct list_head flush_queue;
2083 
2084 	INIT_LIST_HEAD(&flush_queue);
2085 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2086 	rc = 0;
2087 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2088 		/* Check status and move request to flush_queue */
2089 		switch (cqr->status) {
2090 		case DASD_CQR_IN_IO:
2091 			rc = device->discipline->term_IO(cqr);
2092 			if (rc) {
2093 				/* unable to terminate requeust */
2094 				dev_err(&device->cdev->dev,
2095 					"Flushing the DASD request queue "
2096 					"failed for request %p\n", cqr);
2097 				/* stop flush processing */
2098 				goto finished;
2099 			}
2100 			break;
2101 		case DASD_CQR_QUEUED:
2102 			cqr->stopclk = get_tod_clock();
2103 			cqr->status = DASD_CQR_CLEARED;
2104 			break;
2105 		default: /* no need to modify the others */
2106 			break;
2107 		}
2108 		list_move_tail(&cqr->devlist, &flush_queue);
2109 	}
2110 finished:
2111 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2112 	/*
2113 	 * After this point all requests must be in state CLEAR_PENDING,
2114 	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2115 	 * one of the others.
2116 	 */
2117 	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2118 		wait_event(dasd_flush_wq,
2119 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
2120 	/*
2121 	 * Now set each request back to TERMINATED, DONE or NEED_ERP
2122 	 * and call the callback function of flushed requests
2123 	 */
2124 	__dasd_device_process_final_queue(device, &flush_queue);
2125 	return rc;
2126 }
2127 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2128 
2129 /*
2130  * Acquire the device lock and process queues for the device.
2131  */
2132 static void dasd_device_tasklet(struct dasd_device *device)
2133 {
2134 	struct list_head final_queue;
2135 
2136 	atomic_set (&device->tasklet_scheduled, 0);
2137 	INIT_LIST_HEAD(&final_queue);
2138 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2139 	/* Check expire time of first request on the ccw queue. */
2140 	__dasd_device_check_expire(device);
2141 	/* find final requests on ccw queue */
2142 	__dasd_device_process_ccw_queue(device, &final_queue);
2143 	__dasd_device_check_path_events(device);
2144 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2145 	/* Now call the callback function of requests with final status */
2146 	__dasd_device_process_final_queue(device, &final_queue);
2147 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2148 	/* Now check if the head of the ccw queue needs to be started. */
2149 	__dasd_device_start_head(device);
2150 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2151 	if (waitqueue_active(&shutdown_waitq))
2152 		wake_up(&shutdown_waitq);
2153 	dasd_put_device(device);
2154 }
2155 
2156 /*
2157  * Schedules a call to dasd_tasklet over the device tasklet.
2158  */
2159 void dasd_schedule_device_bh(struct dasd_device *device)
2160 {
2161 	/* Protect against rescheduling. */
2162 	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2163 		return;
2164 	dasd_get_device(device);
2165 	tasklet_hi_schedule(&device->tasklet);
2166 }
2167 EXPORT_SYMBOL(dasd_schedule_device_bh);
2168 
2169 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2170 {
2171 	device->stopped |= bits;
2172 }
2173 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2174 
2175 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2176 {
2177 	device->stopped &= ~bits;
2178 	if (!device->stopped)
2179 		wake_up(&generic_waitq);
2180 }
2181 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2182 
2183 /*
2184  * Queue a request to the head of the device ccw_queue.
2185  * Start the I/O if possible.
2186  */
2187 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2188 {
2189 	struct dasd_device *device;
2190 	unsigned long flags;
2191 
2192 	device = cqr->startdev;
2193 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2194 	cqr->status = DASD_CQR_QUEUED;
2195 	list_add(&cqr->devlist, &device->ccw_queue);
2196 	/* let the bh start the request to keep them in order */
2197 	dasd_schedule_device_bh(device);
2198 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2199 }
2200 EXPORT_SYMBOL(dasd_add_request_head);
2201 
2202 /*
2203  * Queue a request to the tail of the device ccw_queue.
2204  * Start the I/O if possible.
2205  */
2206 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2207 {
2208 	struct dasd_device *device;
2209 	unsigned long flags;
2210 
2211 	device = cqr->startdev;
2212 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2213 	cqr->status = DASD_CQR_QUEUED;
2214 	list_add_tail(&cqr->devlist, &device->ccw_queue);
2215 	/* let the bh start the request to keep them in order */
2216 	dasd_schedule_device_bh(device);
2217 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2218 }
2219 EXPORT_SYMBOL(dasd_add_request_tail);
2220 
2221 /*
2222  * Wakeup helper for the 'sleep_on' functions.
2223  */
2224 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2225 {
2226 	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2227 	cqr->callback_data = DASD_SLEEPON_END_TAG;
2228 	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2229 	wake_up(&generic_waitq);
2230 }
2231 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2232 
2233 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2234 {
2235 	struct dasd_device *device;
2236 	int rc;
2237 
2238 	device = cqr->startdev;
2239 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2240 	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2241 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2242 	return rc;
2243 }
2244 
2245 /*
2246  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2247  */
2248 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2249 {
2250 	struct dasd_device *device;
2251 	dasd_erp_fn_t erp_fn;
2252 
2253 	if (cqr->status == DASD_CQR_FILLED)
2254 		return 0;
2255 	device = cqr->startdev;
2256 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2257 		if (cqr->status == DASD_CQR_TERMINATED) {
2258 			device->discipline->handle_terminated_request(cqr);
2259 			return 1;
2260 		}
2261 		if (cqr->status == DASD_CQR_NEED_ERP) {
2262 			erp_fn = device->discipline->erp_action(cqr);
2263 			erp_fn(cqr);
2264 			return 1;
2265 		}
2266 		if (cqr->status == DASD_CQR_FAILED)
2267 			dasd_log_sense(cqr, &cqr->irb);
2268 		if (cqr->refers) {
2269 			__dasd_process_erp(device, cqr);
2270 			return 1;
2271 		}
2272 	}
2273 	return 0;
2274 }
2275 
2276 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2277 {
2278 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2279 		if (cqr->refers) /* erp is not done yet */
2280 			return 1;
2281 		return ((cqr->status != DASD_CQR_DONE) &&
2282 			(cqr->status != DASD_CQR_FAILED));
2283 	} else
2284 		return (cqr->status == DASD_CQR_FILLED);
2285 }
2286 
2287 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2288 {
2289 	struct dasd_device *device;
2290 	int rc;
2291 	struct list_head ccw_queue;
2292 	struct dasd_ccw_req *cqr;
2293 
2294 	INIT_LIST_HEAD(&ccw_queue);
2295 	maincqr->status = DASD_CQR_FILLED;
2296 	device = maincqr->startdev;
2297 	list_add(&maincqr->blocklist, &ccw_queue);
2298 	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2299 	     cqr = list_first_entry(&ccw_queue,
2300 				    struct dasd_ccw_req, blocklist)) {
2301 
2302 		if (__dasd_sleep_on_erp(cqr))
2303 			continue;
2304 		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2305 			continue;
2306 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2307 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2308 			cqr->status = DASD_CQR_FAILED;
2309 			cqr->intrc = -EPERM;
2310 			continue;
2311 		}
2312 		/* Non-temporary stop condition will trigger fail fast */
2313 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2314 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2315 		    (!dasd_eer_enabled(device))) {
2316 			cqr->status = DASD_CQR_FAILED;
2317 			cqr->intrc = -ENOLINK;
2318 			continue;
2319 		}
2320 		/*
2321 		 * Don't try to start requests if device is in
2322 		 * offline processing, it might wait forever
2323 		 */
2324 		if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2325 			cqr->status = DASD_CQR_FAILED;
2326 			cqr->intrc = -ENODEV;
2327 			continue;
2328 		}
2329 		/*
2330 		 * Don't try to start requests if device is stopped
2331 		 * except path verification requests
2332 		 */
2333 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2334 			if (interruptible) {
2335 				rc = wait_event_interruptible(
2336 					generic_waitq, !(device->stopped));
2337 				if (rc == -ERESTARTSYS) {
2338 					cqr->status = DASD_CQR_FAILED;
2339 					maincqr->intrc = rc;
2340 					continue;
2341 				}
2342 			} else
2343 				wait_event(generic_waitq, !(device->stopped));
2344 		}
2345 		if (!cqr->callback)
2346 			cqr->callback = dasd_wakeup_cb;
2347 
2348 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2349 		dasd_add_request_tail(cqr);
2350 		if (interruptible) {
2351 			rc = wait_event_interruptible(
2352 				generic_waitq, _wait_for_wakeup(cqr));
2353 			if (rc == -ERESTARTSYS) {
2354 				dasd_cancel_req(cqr);
2355 				/* wait (non-interruptible) for final status */
2356 				wait_event(generic_waitq,
2357 					   _wait_for_wakeup(cqr));
2358 				cqr->status = DASD_CQR_FAILED;
2359 				maincqr->intrc = rc;
2360 				continue;
2361 			}
2362 		} else
2363 			wait_event(generic_waitq, _wait_for_wakeup(cqr));
2364 	}
2365 
2366 	maincqr->endclk = get_tod_clock();
2367 	if ((maincqr->status != DASD_CQR_DONE) &&
2368 	    (maincqr->intrc != -ERESTARTSYS))
2369 		dasd_log_sense(maincqr, &maincqr->irb);
2370 	if (maincqr->status == DASD_CQR_DONE)
2371 		rc = 0;
2372 	else if (maincqr->intrc)
2373 		rc = maincqr->intrc;
2374 	else
2375 		rc = -EIO;
2376 	return rc;
2377 }
2378 
2379 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2380 {
2381 	struct dasd_ccw_req *cqr;
2382 
2383 	list_for_each_entry(cqr, ccw_queue, blocklist) {
2384 		if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2385 			return 0;
2386 	}
2387 
2388 	return 1;
2389 }
2390 
2391 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2392 {
2393 	struct dasd_device *device;
2394 	struct dasd_ccw_req *cqr, *n;
2395 	u8 *sense = NULL;
2396 	int rc;
2397 
2398 retry:
2399 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2400 		device = cqr->startdev;
2401 		if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2402 			continue;
2403 
2404 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2405 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2406 			cqr->status = DASD_CQR_FAILED;
2407 			cqr->intrc = -EPERM;
2408 			continue;
2409 		}
2410 		/*Non-temporary stop condition will trigger fail fast*/
2411 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2412 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2413 		    !dasd_eer_enabled(device)) {
2414 			cqr->status = DASD_CQR_FAILED;
2415 			cqr->intrc = -EAGAIN;
2416 			continue;
2417 		}
2418 
2419 		/*Don't try to start requests if device is stopped*/
2420 		if (interruptible) {
2421 			rc = wait_event_interruptible(
2422 				generic_waitq, !device->stopped);
2423 			if (rc == -ERESTARTSYS) {
2424 				cqr->status = DASD_CQR_FAILED;
2425 				cqr->intrc = rc;
2426 				continue;
2427 			}
2428 		} else
2429 			wait_event(generic_waitq, !(device->stopped));
2430 
2431 		if (!cqr->callback)
2432 			cqr->callback = dasd_wakeup_cb;
2433 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2434 		dasd_add_request_tail(cqr);
2435 	}
2436 
2437 	wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2438 
2439 	rc = 0;
2440 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2441 		/*
2442 		 * In some cases the 'File Protected' or 'Incorrect Length'
2443 		 * error might be expected and error recovery would be
2444 		 * unnecessary in these cases.	Check if the according suppress
2445 		 * bit is set.
2446 		 */
2447 		sense = dasd_get_sense(&cqr->irb);
2448 		if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2449 		    test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2450 			continue;
2451 		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2452 		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2453 			continue;
2454 
2455 		/*
2456 		 * for alias devices simplify error recovery and
2457 		 * return to upper layer
2458 		 * do not skip ERP requests
2459 		 */
2460 		if (cqr->startdev != cqr->basedev && !cqr->refers &&
2461 		    (cqr->status == DASD_CQR_TERMINATED ||
2462 		     cqr->status == DASD_CQR_NEED_ERP))
2463 			return -EAGAIN;
2464 
2465 		/* normal recovery for basedev IO */
2466 		if (__dasd_sleep_on_erp(cqr))
2467 			/* handle erp first */
2468 			goto retry;
2469 	}
2470 
2471 	return 0;
2472 }
2473 
2474 /*
2475  * Queue a request to the tail of the device ccw_queue and wait for
2476  * it's completion.
2477  */
2478 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2479 {
2480 	return _dasd_sleep_on(cqr, 0);
2481 }
2482 EXPORT_SYMBOL(dasd_sleep_on);
2483 
2484 /*
2485  * Start requests from a ccw_queue and wait for their completion.
2486  */
2487 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2488 {
2489 	return _dasd_sleep_on_queue(ccw_queue, 0);
2490 }
2491 EXPORT_SYMBOL(dasd_sleep_on_queue);
2492 
2493 /*
2494  * Queue a request to the tail of the device ccw_queue and wait
2495  * interruptible for it's completion.
2496  */
2497 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2498 {
2499 	return _dasd_sleep_on(cqr, 1);
2500 }
2501 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2502 
2503 /*
2504  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2505  * for eckd devices) the currently running request has to be terminated
2506  * and be put back to status queued, before the special request is added
2507  * to the head of the queue. Then the special request is waited on normally.
2508  */
2509 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2510 {
2511 	struct dasd_ccw_req *cqr;
2512 	int rc;
2513 
2514 	if (list_empty(&device->ccw_queue))
2515 		return 0;
2516 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2517 	rc = device->discipline->term_IO(cqr);
2518 	if (!rc)
2519 		/*
2520 		 * CQR terminated because a more important request is pending.
2521 		 * Undo decreasing of retry counter because this is
2522 		 * not an error case.
2523 		 */
2524 		cqr->retries++;
2525 	return rc;
2526 }
2527 
2528 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2529 {
2530 	struct dasd_device *device;
2531 	int rc;
2532 
2533 	device = cqr->startdev;
2534 	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2535 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2536 		cqr->status = DASD_CQR_FAILED;
2537 		cqr->intrc = -EPERM;
2538 		return -EIO;
2539 	}
2540 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2541 	rc = _dasd_term_running_cqr(device);
2542 	if (rc) {
2543 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
2544 		return rc;
2545 	}
2546 	cqr->callback = dasd_wakeup_cb;
2547 	cqr->callback_data = DASD_SLEEPON_START_TAG;
2548 	cqr->status = DASD_CQR_QUEUED;
2549 	/*
2550 	 * add new request as second
2551 	 * first the terminated cqr needs to be finished
2552 	 */
2553 	list_add(&cqr->devlist, device->ccw_queue.next);
2554 
2555 	/* let the bh start the request to keep them in order */
2556 	dasd_schedule_device_bh(device);
2557 
2558 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2559 
2560 	wait_event(generic_waitq, _wait_for_wakeup(cqr));
2561 
2562 	if (cqr->status == DASD_CQR_DONE)
2563 		rc = 0;
2564 	else if (cqr->intrc)
2565 		rc = cqr->intrc;
2566 	else
2567 		rc = -EIO;
2568 
2569 	/* kick tasklets */
2570 	dasd_schedule_device_bh(device);
2571 	if (device->block)
2572 		dasd_schedule_block_bh(device->block);
2573 
2574 	return rc;
2575 }
2576 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2577 
2578 /*
2579  * Cancels a request that was started with dasd_sleep_on_req.
2580  * This is useful to timeout requests. The request will be
2581  * terminated if it is currently in i/o.
2582  * Returns 0 if request termination was successful
2583  *	   negative error code if termination failed
2584  * Cancellation of a request is an asynchronous operation! The calling
2585  * function has to wait until the request is properly returned via callback.
2586  */
2587 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2588 {
2589 	struct dasd_device *device = cqr->startdev;
2590 	unsigned long flags;
2591 	int rc;
2592 
2593 	rc = 0;
2594 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2595 	switch (cqr->status) {
2596 	case DASD_CQR_QUEUED:
2597 		/* request was not started - just set to cleared */
2598 		cqr->status = DASD_CQR_CLEARED;
2599 		if (cqr->callback_data == DASD_SLEEPON_START_TAG)
2600 			cqr->callback_data = DASD_SLEEPON_END_TAG;
2601 		break;
2602 	case DASD_CQR_IN_IO:
2603 		/* request in IO - terminate IO and release again */
2604 		rc = device->discipline->term_IO(cqr);
2605 		if (rc) {
2606 			dev_err(&device->cdev->dev,
2607 				"Cancelling request %p failed with rc=%d\n",
2608 				cqr, rc);
2609 		} else {
2610 			cqr->stopclk = get_tod_clock();
2611 		}
2612 		break;
2613 	default: /* already finished or clear pending - do nothing */
2614 		break;
2615 	}
2616 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2617 	dasd_schedule_device_bh(device);
2618 	return rc;
2619 }
2620 EXPORT_SYMBOL(dasd_cancel_req);
2621 
2622 /*
2623  * SECTION: Operations of the dasd_block layer.
2624  */
2625 
2626 /*
2627  * Timeout function for dasd_block. This is used when the block layer
2628  * is waiting for something that may not come reliably, (e.g. a state
2629  * change interrupt)
2630  */
2631 static void dasd_block_timeout(unsigned long ptr)
2632 {
2633 	unsigned long flags;
2634 	struct dasd_block *block;
2635 
2636 	block = (struct dasd_block *) ptr;
2637 	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2638 	/* re-activate request queue */
2639 	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2640 	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2641 	dasd_schedule_block_bh(block);
2642 	blk_mq_run_hw_queues(block->request_queue, true);
2643 }
2644 
2645 /*
2646  * Setup timeout for a dasd_block in jiffies.
2647  */
2648 void dasd_block_set_timer(struct dasd_block *block, int expires)
2649 {
2650 	if (expires == 0)
2651 		del_timer(&block->timer);
2652 	else
2653 		mod_timer(&block->timer, jiffies + expires);
2654 }
2655 EXPORT_SYMBOL(dasd_block_set_timer);
2656 
2657 /*
2658  * Clear timeout for a dasd_block.
2659  */
2660 void dasd_block_clear_timer(struct dasd_block *block)
2661 {
2662 	del_timer(&block->timer);
2663 }
2664 EXPORT_SYMBOL(dasd_block_clear_timer);
2665 
2666 /*
2667  * Process finished error recovery ccw.
2668  */
2669 static void __dasd_process_erp(struct dasd_device *device,
2670 			       struct dasd_ccw_req *cqr)
2671 {
2672 	dasd_erp_fn_t erp_fn;
2673 
2674 	if (cqr->status == DASD_CQR_DONE)
2675 		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2676 	else
2677 		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2678 	erp_fn = device->discipline->erp_postaction(cqr);
2679 	erp_fn(cqr);
2680 }
2681 
2682 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2683 {
2684 	struct request *req;
2685 	blk_status_t error = BLK_STS_OK;
2686 	int status;
2687 
2688 	req = (struct request *) cqr->callback_data;
2689 	dasd_profile_end(cqr->block, cqr, req);
2690 
2691 	status = cqr->block->base->discipline->free_cp(cqr, req);
2692 	if (status < 0)
2693 		error = errno_to_blk_status(status);
2694 	else if (status == 0) {
2695 		switch (cqr->intrc) {
2696 		case -EPERM:
2697 			error = BLK_STS_NEXUS;
2698 			break;
2699 		case -ENOLINK:
2700 			error = BLK_STS_TRANSPORT;
2701 			break;
2702 		case -ETIMEDOUT:
2703 			error = BLK_STS_TIMEOUT;
2704 			break;
2705 		default:
2706 			error = BLK_STS_IOERR;
2707 			break;
2708 		}
2709 	}
2710 
2711 	/*
2712 	 * We need to take care for ETIMEDOUT errors here since the
2713 	 * complete callback does not get called in this case.
2714 	 * Take care of all errors here and avoid additional code to
2715 	 * transfer the error value to the complete callback.
2716 	 */
2717 	if (error) {
2718 		blk_mq_end_request(req, error);
2719 		blk_mq_run_hw_queues(req->q, true);
2720 	} else {
2721 		blk_mq_complete_request(req);
2722 	}
2723 }
2724 
2725 /*
2726  * Process ccw request queue.
2727  */
2728 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2729 					   struct list_head *final_queue)
2730 {
2731 	struct list_head *l, *n;
2732 	struct dasd_ccw_req *cqr;
2733 	dasd_erp_fn_t erp_fn;
2734 	unsigned long flags;
2735 	struct dasd_device *base = block->base;
2736 
2737 restart:
2738 	/* Process request with final status. */
2739 	list_for_each_safe(l, n, &block->ccw_queue) {
2740 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2741 		if (cqr->status != DASD_CQR_DONE &&
2742 		    cqr->status != DASD_CQR_FAILED &&
2743 		    cqr->status != DASD_CQR_NEED_ERP &&
2744 		    cqr->status != DASD_CQR_TERMINATED)
2745 			continue;
2746 
2747 		if (cqr->status == DASD_CQR_TERMINATED) {
2748 			base->discipline->handle_terminated_request(cqr);
2749 			goto restart;
2750 		}
2751 
2752 		/*  Process requests that may be recovered */
2753 		if (cqr->status == DASD_CQR_NEED_ERP) {
2754 			erp_fn = base->discipline->erp_action(cqr);
2755 			if (IS_ERR(erp_fn(cqr)))
2756 				continue;
2757 			goto restart;
2758 		}
2759 
2760 		/* log sense for fatal error */
2761 		if (cqr->status == DASD_CQR_FAILED) {
2762 			dasd_log_sense(cqr, &cqr->irb);
2763 		}
2764 
2765 		/* First of all call extended error reporting. */
2766 		if (dasd_eer_enabled(base) &&
2767 		    cqr->status == DASD_CQR_FAILED) {
2768 			dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2769 
2770 			/* restart request  */
2771 			cqr->status = DASD_CQR_FILLED;
2772 			cqr->retries = 255;
2773 			spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2774 			dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2775 			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2776 					       flags);
2777 			goto restart;
2778 		}
2779 
2780 		/* Process finished ERP request. */
2781 		if (cqr->refers) {
2782 			__dasd_process_erp(base, cqr);
2783 			goto restart;
2784 		}
2785 
2786 		/* Rechain finished requests to final queue */
2787 		cqr->endclk = get_tod_clock();
2788 		list_move_tail(&cqr->blocklist, final_queue);
2789 	}
2790 }
2791 
2792 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2793 {
2794 	dasd_schedule_block_bh(cqr->block);
2795 }
2796 
2797 static void __dasd_block_start_head(struct dasd_block *block)
2798 {
2799 	struct dasd_ccw_req *cqr;
2800 
2801 	if (list_empty(&block->ccw_queue))
2802 		return;
2803 	/* We allways begin with the first requests on the queue, as some
2804 	 * of previously started requests have to be enqueued on a
2805 	 * dasd_device again for error recovery.
2806 	 */
2807 	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2808 		if (cqr->status != DASD_CQR_FILLED)
2809 			continue;
2810 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2811 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2812 			cqr->status = DASD_CQR_FAILED;
2813 			cqr->intrc = -EPERM;
2814 			dasd_schedule_block_bh(block);
2815 			continue;
2816 		}
2817 		/* Non-temporary stop condition will trigger fail fast */
2818 		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2819 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2820 		    (!dasd_eer_enabled(block->base))) {
2821 			cqr->status = DASD_CQR_FAILED;
2822 			cqr->intrc = -ENOLINK;
2823 			dasd_schedule_block_bh(block);
2824 			continue;
2825 		}
2826 		/* Don't try to start requests if device is stopped */
2827 		if (block->base->stopped)
2828 			return;
2829 
2830 		/* just a fail safe check, should not happen */
2831 		if (!cqr->startdev)
2832 			cqr->startdev = block->base;
2833 
2834 		/* make sure that the requests we submit find their way back */
2835 		cqr->callback = dasd_return_cqr_cb;
2836 
2837 		dasd_add_request_tail(cqr);
2838 	}
2839 }
2840 
2841 /*
2842  * Central dasd_block layer routine. Takes requests from the generic
2843  * block layer request queue, creates ccw requests, enqueues them on
2844  * a dasd_device and processes ccw requests that have been returned.
2845  */
2846 static void dasd_block_tasklet(struct dasd_block *block)
2847 {
2848 	struct list_head final_queue;
2849 	struct list_head *l, *n;
2850 	struct dasd_ccw_req *cqr;
2851 	struct dasd_queue *dq;
2852 
2853 	atomic_set(&block->tasklet_scheduled, 0);
2854 	INIT_LIST_HEAD(&final_queue);
2855 	spin_lock_irq(&block->queue_lock);
2856 	/* Finish off requests on ccw queue */
2857 	__dasd_process_block_ccw_queue(block, &final_queue);
2858 	spin_unlock_irq(&block->queue_lock);
2859 
2860 	/* Now call the callback function of requests with final status */
2861 	list_for_each_safe(l, n, &final_queue) {
2862 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2863 		dq = cqr->dq;
2864 		spin_lock_irq(&dq->lock);
2865 		list_del_init(&cqr->blocklist);
2866 		__dasd_cleanup_cqr(cqr);
2867 		spin_unlock_irq(&dq->lock);
2868 	}
2869 
2870 	spin_lock_irq(&block->queue_lock);
2871 	/* Now check if the head of the ccw queue needs to be started. */
2872 	__dasd_block_start_head(block);
2873 	spin_unlock_irq(&block->queue_lock);
2874 
2875 	if (waitqueue_active(&shutdown_waitq))
2876 		wake_up(&shutdown_waitq);
2877 	dasd_put_device(block->base);
2878 }
2879 
2880 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2881 {
2882 	wake_up(&dasd_flush_wq);
2883 }
2884 
2885 /*
2886  * Requeue a request back to the block request queue
2887  * only works for block requests
2888  */
2889 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2890 {
2891 	struct dasd_block *block = cqr->block;
2892 	struct request *req;
2893 
2894 	if (!block)
2895 		return -EINVAL;
2896 	spin_lock_irq(&cqr->dq->lock);
2897 	req = (struct request *) cqr->callback_data;
2898 	blk_mq_requeue_request(req, false);
2899 	spin_unlock_irq(&cqr->dq->lock);
2900 
2901 	return 0;
2902 }
2903 
2904 /*
2905  * Go through all request on the dasd_block request queue, cancel them
2906  * on the respective dasd_device, and return them to the generic
2907  * block layer.
2908  */
2909 static int dasd_flush_block_queue(struct dasd_block *block)
2910 {
2911 	struct dasd_ccw_req *cqr, *n;
2912 	int rc, i;
2913 	struct list_head flush_queue;
2914 	unsigned long flags;
2915 
2916 	INIT_LIST_HEAD(&flush_queue);
2917 	spin_lock_bh(&block->queue_lock);
2918 	rc = 0;
2919 restart:
2920 	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2921 		/* if this request currently owned by a dasd_device cancel it */
2922 		if (cqr->status >= DASD_CQR_QUEUED)
2923 			rc = dasd_cancel_req(cqr);
2924 		if (rc < 0)
2925 			break;
2926 		/* Rechain request (including erp chain) so it won't be
2927 		 * touched by the dasd_block_tasklet anymore.
2928 		 * Replace the callback so we notice when the request
2929 		 * is returned from the dasd_device layer.
2930 		 */
2931 		cqr->callback = _dasd_wake_block_flush_cb;
2932 		for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2933 			list_move_tail(&cqr->blocklist, &flush_queue);
2934 		if (i > 1)
2935 			/* moved more than one request - need to restart */
2936 			goto restart;
2937 	}
2938 	spin_unlock_bh(&block->queue_lock);
2939 	/* Now call the callback function of flushed requests */
2940 restart_cb:
2941 	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2942 		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2943 		/* Process finished ERP request. */
2944 		if (cqr->refers) {
2945 			spin_lock_bh(&block->queue_lock);
2946 			__dasd_process_erp(block->base, cqr);
2947 			spin_unlock_bh(&block->queue_lock);
2948 			/* restart list_for_xx loop since dasd_process_erp
2949 			 * might remove multiple elements */
2950 			goto restart_cb;
2951 		}
2952 		/* call the callback function */
2953 		spin_lock_irqsave(&cqr->dq->lock, flags);
2954 		cqr->endclk = get_tod_clock();
2955 		list_del_init(&cqr->blocklist);
2956 		__dasd_cleanup_cqr(cqr);
2957 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
2958 	}
2959 	return rc;
2960 }
2961 
2962 /*
2963  * Schedules a call to dasd_tasklet over the device tasklet.
2964  */
2965 void dasd_schedule_block_bh(struct dasd_block *block)
2966 {
2967 	/* Protect against rescheduling. */
2968 	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2969 		return;
2970 	/* life cycle of block is bound to it's base device */
2971 	dasd_get_device(block->base);
2972 	tasklet_hi_schedule(&block->tasklet);
2973 }
2974 EXPORT_SYMBOL(dasd_schedule_block_bh);
2975 
2976 
2977 /*
2978  * SECTION: external block device operations
2979  * (request queue handling, open, release, etc.)
2980  */
2981 
2982 /*
2983  * Dasd request queue function. Called from ll_rw_blk.c
2984  */
2985 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
2986 				    const struct blk_mq_queue_data *qd)
2987 {
2988 	struct dasd_block *block = hctx->queue->queuedata;
2989 	struct dasd_queue *dq = hctx->driver_data;
2990 	struct request *req = qd->rq;
2991 	struct dasd_device *basedev;
2992 	struct dasd_ccw_req *cqr;
2993 	blk_status_t rc = BLK_STS_OK;
2994 
2995 	basedev = block->base;
2996 	spin_lock_irq(&dq->lock);
2997 	if (basedev->state < DASD_STATE_READY) {
2998 		DBF_DEV_EVENT(DBF_ERR, basedev,
2999 			      "device not ready for request %p", req);
3000 		rc = BLK_STS_IOERR;
3001 		goto out;
3002 	}
3003 
3004 	/*
3005 	 * if device is stopped do not fetch new requests
3006 	 * except failfast is active which will let requests fail
3007 	 * immediately in __dasd_block_start_head()
3008 	 */
3009 	if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3010 		DBF_DEV_EVENT(DBF_ERR, basedev,
3011 			      "device stopped request %p", req);
3012 		rc = BLK_STS_RESOURCE;
3013 		goto out;
3014 	}
3015 
3016 	if (basedev->features & DASD_FEATURE_READONLY &&
3017 	    rq_data_dir(req) == WRITE) {
3018 		DBF_DEV_EVENT(DBF_ERR, basedev,
3019 			      "Rejecting write request %p", req);
3020 		rc = BLK_STS_IOERR;
3021 		goto out;
3022 	}
3023 
3024 	if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3025 	    (basedev->features & DASD_FEATURE_FAILFAST ||
3026 	     blk_noretry_request(req))) {
3027 		DBF_DEV_EVENT(DBF_ERR, basedev,
3028 			      "Rejecting failfast request %p", req);
3029 		rc = BLK_STS_IOERR;
3030 		goto out;
3031 	}
3032 
3033 	cqr = basedev->discipline->build_cp(basedev, block, req);
3034 	if (IS_ERR(cqr)) {
3035 		if (PTR_ERR(cqr) == -EBUSY ||
3036 		    PTR_ERR(cqr) == -ENOMEM ||
3037 		    PTR_ERR(cqr) == -EAGAIN) {
3038 			rc = BLK_STS_RESOURCE;
3039 			goto out;
3040 		}
3041 		DBF_DEV_EVENT(DBF_ERR, basedev,
3042 			      "CCW creation failed (rc=%ld) on request %p",
3043 			      PTR_ERR(cqr), req);
3044 		rc = BLK_STS_IOERR;
3045 		goto out;
3046 	}
3047 	/*
3048 	 *  Note: callback is set to dasd_return_cqr_cb in
3049 	 * __dasd_block_start_head to cover erp requests as well
3050 	 */
3051 	cqr->callback_data = req;
3052 	cqr->status = DASD_CQR_FILLED;
3053 	cqr->dq = dq;
3054 	req->completion_data = cqr;
3055 	blk_mq_start_request(req);
3056 	spin_lock(&block->queue_lock);
3057 	list_add_tail(&cqr->blocklist, &block->ccw_queue);
3058 	INIT_LIST_HEAD(&cqr->devlist);
3059 	dasd_profile_start(block, cqr, req);
3060 	dasd_schedule_block_bh(block);
3061 	spin_unlock(&block->queue_lock);
3062 
3063 out:
3064 	spin_unlock_irq(&dq->lock);
3065 	return rc;
3066 }
3067 
3068 /*
3069  * Block timeout callback, called from the block layer
3070  *
3071  * Return values:
3072  * BLK_EH_RESET_TIMER if the request should be left running
3073  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3074  *		      by the driver.
3075  */
3076 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3077 {
3078 	struct dasd_ccw_req *cqr = req->completion_data;
3079 	struct dasd_block *block = req->q->queuedata;
3080 	struct dasd_device *device;
3081 	unsigned long flags;
3082 	int rc = 0;
3083 
3084 	if (!cqr)
3085 		return BLK_EH_NOT_HANDLED;
3086 
3087 	spin_lock_irqsave(&cqr->dq->lock, flags);
3088 	device = cqr->startdev ? cqr->startdev : block->base;
3089 	if (!device->blk_timeout) {
3090 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3091 		return BLK_EH_RESET_TIMER;
3092 	}
3093 	DBF_DEV_EVENT(DBF_WARNING, device,
3094 		      " dasd_times_out cqr %p status %x",
3095 		      cqr, cqr->status);
3096 
3097 	spin_lock(&block->queue_lock);
3098 	spin_lock(get_ccwdev_lock(device->cdev));
3099 	cqr->retries = -1;
3100 	cqr->intrc = -ETIMEDOUT;
3101 	if (cqr->status >= DASD_CQR_QUEUED) {
3102 		spin_unlock(get_ccwdev_lock(device->cdev));
3103 		rc = dasd_cancel_req(cqr);
3104 	} else if (cqr->status == DASD_CQR_FILLED ||
3105 		   cqr->status == DASD_CQR_NEED_ERP) {
3106 		cqr->status = DASD_CQR_TERMINATED;
3107 		spin_unlock(get_ccwdev_lock(device->cdev));
3108 	} else if (cqr->status == DASD_CQR_IN_ERP) {
3109 		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3110 
3111 		list_for_each_entry_safe(searchcqr, nextcqr,
3112 					 &block->ccw_queue, blocklist) {
3113 			tmpcqr = searchcqr;
3114 			while (tmpcqr->refers)
3115 				tmpcqr = tmpcqr->refers;
3116 			if (tmpcqr != cqr)
3117 				continue;
3118 			/* searchcqr is an ERP request for cqr */
3119 			searchcqr->retries = -1;
3120 			searchcqr->intrc = -ETIMEDOUT;
3121 			if (searchcqr->status >= DASD_CQR_QUEUED) {
3122 				spin_unlock(get_ccwdev_lock(device->cdev));
3123 				rc = dasd_cancel_req(searchcqr);
3124 				spin_lock(get_ccwdev_lock(device->cdev));
3125 			} else if ((searchcqr->status == DASD_CQR_FILLED) ||
3126 				   (searchcqr->status == DASD_CQR_NEED_ERP)) {
3127 				searchcqr->status = DASD_CQR_TERMINATED;
3128 				rc = 0;
3129 			} else if (searchcqr->status == DASD_CQR_IN_ERP) {
3130 				/*
3131 				 * Shouldn't happen; most recent ERP
3132 				 * request is at the front of queue
3133 				 */
3134 				continue;
3135 			}
3136 			break;
3137 		}
3138 		spin_unlock(get_ccwdev_lock(device->cdev));
3139 	}
3140 	dasd_schedule_block_bh(block);
3141 	spin_unlock(&block->queue_lock);
3142 	spin_unlock_irqrestore(&cqr->dq->lock, flags);
3143 
3144 	return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3145 }
3146 
3147 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3148 			  unsigned int idx)
3149 {
3150 	struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3151 
3152 	if (!dq)
3153 		return -ENOMEM;
3154 
3155 	spin_lock_init(&dq->lock);
3156 	hctx->driver_data = dq;
3157 
3158 	return 0;
3159 }
3160 
3161 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3162 {
3163 	kfree(hctx->driver_data);
3164 	hctx->driver_data = NULL;
3165 }
3166 
3167 static void dasd_request_done(struct request *req)
3168 {
3169 	blk_mq_end_request(req, 0);
3170 	blk_mq_run_hw_queues(req->q, true);
3171 }
3172 
3173 static struct blk_mq_ops dasd_mq_ops = {
3174 	.queue_rq = do_dasd_request,
3175 	.complete = dasd_request_done,
3176 	.timeout = dasd_times_out,
3177 	.init_hctx = dasd_init_hctx,
3178 	.exit_hctx = dasd_exit_hctx,
3179 };
3180 
3181 /*
3182  * Allocate and initialize request queue and default I/O scheduler.
3183  */
3184 static int dasd_alloc_queue(struct dasd_block *block)
3185 {
3186 	int rc;
3187 
3188 	block->tag_set.ops = &dasd_mq_ops;
3189 	block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES;
3190 	block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV;
3191 	block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3192 
3193 	rc = blk_mq_alloc_tag_set(&block->tag_set);
3194 	if (rc)
3195 		return rc;
3196 
3197 	block->request_queue = blk_mq_init_queue(&block->tag_set);
3198 	if (IS_ERR(block->request_queue))
3199 		return PTR_ERR(block->request_queue);
3200 
3201 	block->request_queue->queuedata = block;
3202 
3203 	return 0;
3204 }
3205 
3206 /*
3207  * Allocate and initialize request queue.
3208  */
3209 static void dasd_setup_queue(struct dasd_block *block)
3210 {
3211 	unsigned int logical_block_size = block->bp_block;
3212 	struct request_queue *q = block->request_queue;
3213 	unsigned int max_bytes, max_discard_sectors;
3214 	int max;
3215 
3216 	if (block->base->features & DASD_FEATURE_USERAW) {
3217 		/*
3218 		 * the max_blocks value for raw_track access is 256
3219 		 * it is higher than the native ECKD value because we
3220 		 * only need one ccw per track
3221 		 * so the max_hw_sectors are
3222 		 * 2048 x 512B = 1024kB = 16 tracks
3223 		 */
3224 		max = 2048;
3225 	} else {
3226 		max = block->base->discipline->max_blocks << block->s2b_shift;
3227 	}
3228 	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
3229 	q->limits.max_dev_sectors = max;
3230 	blk_queue_logical_block_size(q, logical_block_size);
3231 	blk_queue_max_hw_sectors(q, max);
3232 	blk_queue_max_segments(q, USHRT_MAX);
3233 	/* with page sized segments we can translate each segement into
3234 	 * one idaw/tidaw
3235 	 */
3236 	blk_queue_max_segment_size(q, PAGE_SIZE);
3237 	blk_queue_segment_boundary(q, PAGE_SIZE - 1);
3238 
3239 	/* Only activate blocklayer discard support for devices that support it */
3240 	if (block->base->features & DASD_FEATURE_DISCARD) {
3241 		q->limits.discard_granularity = logical_block_size;
3242 		q->limits.discard_alignment = PAGE_SIZE;
3243 
3244 		/* Calculate max_discard_sectors and make it PAGE aligned */
3245 		max_bytes = USHRT_MAX * logical_block_size;
3246 		max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE;
3247 		max_discard_sectors = max_bytes / logical_block_size;
3248 
3249 		blk_queue_max_discard_sectors(q, max_discard_sectors);
3250 		blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
3251 		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
3252 	}
3253 }
3254 
3255 /*
3256  * Deactivate and free request queue.
3257  */
3258 static void dasd_free_queue(struct dasd_block *block)
3259 {
3260 	if (block->request_queue) {
3261 		blk_cleanup_queue(block->request_queue);
3262 		blk_mq_free_tag_set(&block->tag_set);
3263 		block->request_queue = NULL;
3264 	}
3265 }
3266 
3267 static int dasd_open(struct block_device *bdev, fmode_t mode)
3268 {
3269 	struct dasd_device *base;
3270 	int rc;
3271 
3272 	base = dasd_device_from_gendisk(bdev->bd_disk);
3273 	if (!base)
3274 		return -ENODEV;
3275 
3276 	atomic_inc(&base->block->open_count);
3277 	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3278 		rc = -ENODEV;
3279 		goto unlock;
3280 	}
3281 
3282 	if (!try_module_get(base->discipline->owner)) {
3283 		rc = -EINVAL;
3284 		goto unlock;
3285 	}
3286 
3287 	if (dasd_probeonly) {
3288 		dev_info(&base->cdev->dev,
3289 			 "Accessing the DASD failed because it is in "
3290 			 "probeonly mode\n");
3291 		rc = -EPERM;
3292 		goto out;
3293 	}
3294 
3295 	if (base->state <= DASD_STATE_BASIC) {
3296 		DBF_DEV_EVENT(DBF_ERR, base, " %s",
3297 			      " Cannot open unrecognized device");
3298 		rc = -ENODEV;
3299 		goto out;
3300 	}
3301 
3302 	if ((mode & FMODE_WRITE) &&
3303 	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3304 	     (base->features & DASD_FEATURE_READONLY))) {
3305 		rc = -EROFS;
3306 		goto out;
3307 	}
3308 
3309 	dasd_put_device(base);
3310 	return 0;
3311 
3312 out:
3313 	module_put(base->discipline->owner);
3314 unlock:
3315 	atomic_dec(&base->block->open_count);
3316 	dasd_put_device(base);
3317 	return rc;
3318 }
3319 
3320 static void dasd_release(struct gendisk *disk, fmode_t mode)
3321 {
3322 	struct dasd_device *base = dasd_device_from_gendisk(disk);
3323 	if (base) {
3324 		atomic_dec(&base->block->open_count);
3325 		module_put(base->discipline->owner);
3326 		dasd_put_device(base);
3327 	}
3328 }
3329 
3330 /*
3331  * Return disk geometry.
3332  */
3333 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3334 {
3335 	struct dasd_device *base;
3336 
3337 	base = dasd_device_from_gendisk(bdev->bd_disk);
3338 	if (!base)
3339 		return -ENODEV;
3340 
3341 	if (!base->discipline ||
3342 	    !base->discipline->fill_geometry) {
3343 		dasd_put_device(base);
3344 		return -EINVAL;
3345 	}
3346 	base->discipline->fill_geometry(base->block, geo);
3347 	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3348 	dasd_put_device(base);
3349 	return 0;
3350 }
3351 
3352 const struct block_device_operations
3353 dasd_device_operations = {
3354 	.owner		= THIS_MODULE,
3355 	.open		= dasd_open,
3356 	.release	= dasd_release,
3357 	.ioctl		= dasd_ioctl,
3358 	.compat_ioctl	= dasd_ioctl,
3359 	.getgeo		= dasd_getgeo,
3360 };
3361 
3362 /*******************************************************************************
3363  * end of block device operations
3364  */
3365 
3366 static void
3367 dasd_exit(void)
3368 {
3369 #ifdef CONFIG_PROC_FS
3370 	dasd_proc_exit();
3371 #endif
3372 	dasd_eer_exit();
3373         if (dasd_page_cache != NULL) {
3374 		kmem_cache_destroy(dasd_page_cache);
3375 		dasd_page_cache = NULL;
3376 	}
3377 	dasd_gendisk_exit();
3378 	dasd_devmap_exit();
3379 	if (dasd_debug_area != NULL) {
3380 		debug_unregister(dasd_debug_area);
3381 		dasd_debug_area = NULL;
3382 	}
3383 	dasd_statistics_removeroot();
3384 }
3385 
3386 /*
3387  * SECTION: common functions for ccw_driver use
3388  */
3389 
3390 /*
3391  * Is the device read-only?
3392  * Note that this function does not report the setting of the
3393  * readonly device attribute, but how it is configured in z/VM.
3394  */
3395 int dasd_device_is_ro(struct dasd_device *device)
3396 {
3397 	struct ccw_dev_id dev_id;
3398 	struct diag210 diag_data;
3399 	int rc;
3400 
3401 	if (!MACHINE_IS_VM)
3402 		return 0;
3403 	ccw_device_get_id(device->cdev, &dev_id);
3404 	memset(&diag_data, 0, sizeof(diag_data));
3405 	diag_data.vrdcdvno = dev_id.devno;
3406 	diag_data.vrdclen = sizeof(diag_data);
3407 	rc = diag210(&diag_data);
3408 	if (rc == 0 || rc == 2) {
3409 		return diag_data.vrdcvfla & 0x80;
3410 	} else {
3411 		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3412 			  dev_id.devno, rc);
3413 		return 0;
3414 	}
3415 }
3416 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3417 
3418 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3419 {
3420 	struct ccw_device *cdev = data;
3421 	int ret;
3422 
3423 	ret = ccw_device_set_online(cdev);
3424 	if (ret)
3425 		pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3426 			dev_name(&cdev->dev), ret);
3427 }
3428 
3429 /*
3430  * Initial attempt at a probe function. this can be simplified once
3431  * the other detection code is gone.
3432  */
3433 int dasd_generic_probe(struct ccw_device *cdev,
3434 		       struct dasd_discipline *discipline)
3435 {
3436 	int ret;
3437 
3438 	ret = dasd_add_sysfs_files(cdev);
3439 	if (ret) {
3440 		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
3441 				"dasd_generic_probe: could not add "
3442 				"sysfs entries");
3443 		return ret;
3444 	}
3445 	cdev->handler = &dasd_int_handler;
3446 
3447 	/*
3448 	 * Automatically online either all dasd devices (dasd_autodetect)
3449 	 * or all devices specified with dasd= parameters during
3450 	 * initial probe.
3451 	 */
3452 	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3453 	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3454 		async_schedule(dasd_generic_auto_online, cdev);
3455 	return 0;
3456 }
3457 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3458 
3459 void dasd_generic_free_discipline(struct dasd_device *device)
3460 {
3461 	/* Forget the discipline information. */
3462 	if (device->discipline) {
3463 		if (device->discipline->uncheck_device)
3464 			device->discipline->uncheck_device(device);
3465 		module_put(device->discipline->owner);
3466 		device->discipline = NULL;
3467 	}
3468 	if (device->base_discipline) {
3469 		module_put(device->base_discipline->owner);
3470 		device->base_discipline = NULL;
3471 	}
3472 }
3473 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3474 
3475 /*
3476  * This will one day be called from a global not_oper handler.
3477  * It is also used by driver_unregister during module unload.
3478  */
3479 void dasd_generic_remove(struct ccw_device *cdev)
3480 {
3481 	struct dasd_device *device;
3482 	struct dasd_block *block;
3483 
3484 	cdev->handler = NULL;
3485 
3486 	device = dasd_device_from_cdev(cdev);
3487 	if (IS_ERR(device)) {
3488 		dasd_remove_sysfs_files(cdev);
3489 		return;
3490 	}
3491 	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3492 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3493 		/* Already doing offline processing */
3494 		dasd_put_device(device);
3495 		dasd_remove_sysfs_files(cdev);
3496 		return;
3497 	}
3498 	/*
3499 	 * This device is removed unconditionally. Set offline
3500 	 * flag to prevent dasd_open from opening it while it is
3501 	 * no quite down yet.
3502 	 */
3503 	dasd_set_target_state(device, DASD_STATE_NEW);
3504 	/* dasd_delete_device destroys the device reference. */
3505 	block = device->block;
3506 	dasd_delete_device(device);
3507 	/*
3508 	 * life cycle of block is bound to device, so delete it after
3509 	 * device was safely removed
3510 	 */
3511 	if (block)
3512 		dasd_free_block(block);
3513 
3514 	dasd_remove_sysfs_files(cdev);
3515 }
3516 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3517 
3518 /*
3519  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3520  * the device is detected for the first time and is supposed to be used
3521  * or the user has started activation through sysfs.
3522  */
3523 int dasd_generic_set_online(struct ccw_device *cdev,
3524 			    struct dasd_discipline *base_discipline)
3525 {
3526 	struct dasd_discipline *discipline;
3527 	struct dasd_device *device;
3528 	int rc;
3529 
3530 	/* first online clears initial online feature flag */
3531 	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3532 	device = dasd_create_device(cdev);
3533 	if (IS_ERR(device))
3534 		return PTR_ERR(device);
3535 
3536 	discipline = base_discipline;
3537 	if (device->features & DASD_FEATURE_USEDIAG) {
3538 	  	if (!dasd_diag_discipline_pointer) {
3539 			/* Try to load the required module. */
3540 			rc = request_module(DASD_DIAG_MOD);
3541 			if (rc) {
3542 				pr_warn("%s Setting the DASD online failed "
3543 					"because the required module %s "
3544 					"could not be loaded (rc=%d)\n",
3545 					dev_name(&cdev->dev), DASD_DIAG_MOD,
3546 					rc);
3547 				dasd_delete_device(device);
3548 				return -ENODEV;
3549 			}
3550 		}
3551 		/* Module init could have failed, so check again here after
3552 		 * request_module(). */
3553 		if (!dasd_diag_discipline_pointer) {
3554 			pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3555 				dev_name(&cdev->dev));
3556 			dasd_delete_device(device);
3557 			return -ENODEV;
3558 		}
3559 		discipline = dasd_diag_discipline_pointer;
3560 	}
3561 	if (!try_module_get(base_discipline->owner)) {
3562 		dasd_delete_device(device);
3563 		return -EINVAL;
3564 	}
3565 	if (!try_module_get(discipline->owner)) {
3566 		module_put(base_discipline->owner);
3567 		dasd_delete_device(device);
3568 		return -EINVAL;
3569 	}
3570 	device->base_discipline = base_discipline;
3571 	device->discipline = discipline;
3572 
3573 	/* check_device will allocate block device if necessary */
3574 	rc = discipline->check_device(device);
3575 	if (rc) {
3576 		pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3577 			dev_name(&cdev->dev), discipline->name, rc);
3578 		module_put(discipline->owner);
3579 		module_put(base_discipline->owner);
3580 		dasd_delete_device(device);
3581 		return rc;
3582 	}
3583 
3584 	dasd_set_target_state(device, DASD_STATE_ONLINE);
3585 	if (device->state <= DASD_STATE_KNOWN) {
3586 		pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3587 			dev_name(&cdev->dev));
3588 		rc = -ENODEV;
3589 		dasd_set_target_state(device, DASD_STATE_NEW);
3590 		if (device->block)
3591 			dasd_free_block(device->block);
3592 		dasd_delete_device(device);
3593 	} else
3594 		pr_debug("dasd_generic device %s found\n",
3595 				dev_name(&cdev->dev));
3596 
3597 	wait_event(dasd_init_waitq, _wait_for_device(device));
3598 
3599 	dasd_put_device(device);
3600 	return rc;
3601 }
3602 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3603 
3604 int dasd_generic_set_offline(struct ccw_device *cdev)
3605 {
3606 	struct dasd_device *device;
3607 	struct dasd_block *block;
3608 	int max_count, open_count, rc;
3609 	unsigned long flags;
3610 
3611 	rc = 0;
3612 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3613 	device = dasd_device_from_cdev_locked(cdev);
3614 	if (IS_ERR(device)) {
3615 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3616 		return PTR_ERR(device);
3617 	}
3618 
3619 	/*
3620 	 * We must make sure that this device is currently not in use.
3621 	 * The open_count is increased for every opener, that includes
3622 	 * the blkdev_get in dasd_scan_partitions. We are only interested
3623 	 * in the other openers.
3624 	 */
3625 	if (device->block) {
3626 		max_count = device->block->bdev ? 0 : -1;
3627 		open_count = atomic_read(&device->block->open_count);
3628 		if (open_count > max_count) {
3629 			if (open_count > 0)
3630 				pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3631 					dev_name(&cdev->dev), open_count);
3632 			else
3633 				pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3634 					dev_name(&cdev->dev));
3635 			rc = -EBUSY;
3636 			goto out_err;
3637 		}
3638 	}
3639 
3640 	/*
3641 	 * Test if the offline processing is already running and exit if so.
3642 	 * If a safe offline is being processed this could only be a normal
3643 	 * offline that should be able to overtake the safe offline and
3644 	 * cancel any I/O we do not want to wait for any longer
3645 	 */
3646 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3647 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3648 			clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3649 				  &device->flags);
3650 		} else {
3651 			rc = -EBUSY;
3652 			goto out_err;
3653 		}
3654 	}
3655 	set_bit(DASD_FLAG_OFFLINE, &device->flags);
3656 
3657 	/*
3658 	 * if safe_offline is called set safe_offline_running flag and
3659 	 * clear safe_offline so that a call to normal offline
3660 	 * can overrun safe_offline processing
3661 	 */
3662 	if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3663 	    !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3664 		/* need to unlock here to wait for outstanding I/O */
3665 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3666 		/*
3667 		 * If we want to set the device safe offline all IO operations
3668 		 * should be finished before continuing the offline process
3669 		 * so sync bdev first and then wait for our queues to become
3670 		 * empty
3671 		 */
3672 		if (device->block) {
3673 			rc = fsync_bdev(device->block->bdev);
3674 			if (rc != 0)
3675 				goto interrupted;
3676 		}
3677 		dasd_schedule_device_bh(device);
3678 		rc = wait_event_interruptible(shutdown_waitq,
3679 					      _wait_for_empty_queues(device));
3680 		if (rc != 0)
3681 			goto interrupted;
3682 
3683 		/*
3684 		 * check if a normal offline process overtook the offline
3685 		 * processing in this case simply do nothing beside returning
3686 		 * that we got interrupted
3687 		 * otherwise mark safe offline as not running any longer and
3688 		 * continue with normal offline
3689 		 */
3690 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3691 		if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3692 			rc = -ERESTARTSYS;
3693 			goto out_err;
3694 		}
3695 		clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3696 	}
3697 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3698 
3699 	dasd_set_target_state(device, DASD_STATE_NEW);
3700 	/* dasd_delete_device destroys the device reference. */
3701 	block = device->block;
3702 	dasd_delete_device(device);
3703 	/*
3704 	 * life cycle of block is bound to device, so delete it after
3705 	 * device was safely removed
3706 	 */
3707 	if (block)
3708 		dasd_free_block(block);
3709 
3710 	return 0;
3711 
3712 interrupted:
3713 	/* interrupted by signal */
3714 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3715 	clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3716 	clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3717 out_err:
3718 	dasd_put_device(device);
3719 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3720 	return rc;
3721 }
3722 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3723 
3724 int dasd_generic_last_path_gone(struct dasd_device *device)
3725 {
3726 	struct dasd_ccw_req *cqr;
3727 
3728 	dev_warn(&device->cdev->dev, "No operational channel path is left "
3729 		 "for the device\n");
3730 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3731 	/* First of all call extended error reporting. */
3732 	dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3733 
3734 	if (device->state < DASD_STATE_BASIC)
3735 		return 0;
3736 	/* Device is active. We want to keep it. */
3737 	list_for_each_entry(cqr, &device->ccw_queue, devlist)
3738 		if ((cqr->status == DASD_CQR_IN_IO) ||
3739 		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3740 			cqr->status = DASD_CQR_QUEUED;
3741 			cqr->retries++;
3742 		}
3743 	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3744 	dasd_device_clear_timer(device);
3745 	dasd_schedule_device_bh(device);
3746 	return 1;
3747 }
3748 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3749 
3750 int dasd_generic_path_operational(struct dasd_device *device)
3751 {
3752 	dev_info(&device->cdev->dev, "A channel path to the device has become "
3753 		 "operational\n");
3754 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3755 	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3756 	if (device->stopped & DASD_UNRESUMED_PM) {
3757 		dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
3758 		dasd_restore_device(device);
3759 		return 1;
3760 	}
3761 	dasd_schedule_device_bh(device);
3762 	if (device->block) {
3763 		dasd_schedule_block_bh(device->block);
3764 		if (device->block->request_queue)
3765 			blk_mq_run_hw_queues(device->block->request_queue,
3766 					     true);
3767 		}
3768 
3769 	if (!device->stopped)
3770 		wake_up(&generic_waitq);
3771 
3772 	return 1;
3773 }
3774 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3775 
3776 int dasd_generic_notify(struct ccw_device *cdev, int event)
3777 {
3778 	struct dasd_device *device;
3779 	int ret;
3780 
3781 	device = dasd_device_from_cdev_locked(cdev);
3782 	if (IS_ERR(device))
3783 		return 0;
3784 	ret = 0;
3785 	switch (event) {
3786 	case CIO_GONE:
3787 	case CIO_BOXED:
3788 	case CIO_NO_PATH:
3789 		dasd_path_no_path(device);
3790 		ret = dasd_generic_last_path_gone(device);
3791 		break;
3792 	case CIO_OPER:
3793 		ret = 1;
3794 		if (dasd_path_get_opm(device))
3795 			ret = dasd_generic_path_operational(device);
3796 		break;
3797 	}
3798 	dasd_put_device(device);
3799 	return ret;
3800 }
3801 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3802 
3803 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3804 {
3805 	struct dasd_device *device;
3806 	int chp, oldopm, hpfpm, ifccpm;
3807 
3808 	device = dasd_device_from_cdev_locked(cdev);
3809 	if (IS_ERR(device))
3810 		return;
3811 
3812 	oldopm = dasd_path_get_opm(device);
3813 	for (chp = 0; chp < 8; chp++) {
3814 		if (path_event[chp] & PE_PATH_GONE) {
3815 			dasd_path_notoper(device, chp);
3816 		}
3817 		if (path_event[chp] & PE_PATH_AVAILABLE) {
3818 			dasd_path_available(device, chp);
3819 			dasd_schedule_device_bh(device);
3820 		}
3821 		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3822 			if (!dasd_path_is_operational(device, chp) &&
3823 			    !dasd_path_need_verify(device, chp)) {
3824 				/*
3825 				 * we can not establish a pathgroup on an
3826 				 * unavailable path, so trigger a path
3827 				 * verification first
3828 				 */
3829 			dasd_path_available(device, chp);
3830 			dasd_schedule_device_bh(device);
3831 			}
3832 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3833 				      "Pathgroup re-established\n");
3834 			if (device->discipline->kick_validate)
3835 				device->discipline->kick_validate(device);
3836 		}
3837 	}
3838 	hpfpm = dasd_path_get_hpfpm(device);
3839 	ifccpm = dasd_path_get_ifccpm(device);
3840 	if (!dasd_path_get_opm(device) && hpfpm) {
3841 		/*
3842 		 * device has no operational paths but at least one path is
3843 		 * disabled due to HPF errors
3844 		 * disable HPF at all and use the path(s) again
3845 		 */
3846 		if (device->discipline->disable_hpf)
3847 			device->discipline->disable_hpf(device);
3848 		dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3849 		dasd_path_set_tbvpm(device, hpfpm);
3850 		dasd_schedule_device_bh(device);
3851 		dasd_schedule_requeue(device);
3852 	} else if (!dasd_path_get_opm(device) && ifccpm) {
3853 		/*
3854 		 * device has no operational paths but at least one path is
3855 		 * disabled due to IFCC errors
3856 		 * trigger path verification on paths with IFCC errors
3857 		 */
3858 		dasd_path_set_tbvpm(device, ifccpm);
3859 		dasd_schedule_device_bh(device);
3860 	}
3861 	if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3862 		dev_warn(&device->cdev->dev,
3863 			 "No verified channel paths remain for the device\n");
3864 		DBF_DEV_EVENT(DBF_WARNING, device,
3865 			      "%s", "last verified path gone");
3866 		dasd_eer_write(device, NULL, DASD_EER_NOPATH);
3867 		dasd_device_set_stop_bits(device,
3868 					  DASD_STOPPED_DC_WAIT);
3869 	}
3870 	dasd_put_device(device);
3871 }
3872 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3873 
3874 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3875 {
3876 	if (!dasd_path_get_opm(device) && lpm) {
3877 		dasd_path_set_opm(device, lpm);
3878 		dasd_generic_path_operational(device);
3879 	} else
3880 		dasd_path_add_opm(device, lpm);
3881 	return 0;
3882 }
3883 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3884 
3885 /*
3886  * clear active requests and requeue them to block layer if possible
3887  */
3888 static int dasd_generic_requeue_all_requests(struct dasd_device *device)
3889 {
3890 	struct list_head requeue_queue;
3891 	struct dasd_ccw_req *cqr, *n;
3892 	struct dasd_ccw_req *refers;
3893 	int rc;
3894 
3895 	INIT_LIST_HEAD(&requeue_queue);
3896 	spin_lock_irq(get_ccwdev_lock(device->cdev));
3897 	rc = 0;
3898 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
3899 		/* Check status and move request to flush_queue */
3900 		if (cqr->status == DASD_CQR_IN_IO) {
3901 			rc = device->discipline->term_IO(cqr);
3902 			if (rc) {
3903 				/* unable to terminate requeust */
3904 				dev_err(&device->cdev->dev,
3905 					"Unable to terminate request %p "
3906 					"on suspend\n", cqr);
3907 				spin_unlock_irq(get_ccwdev_lock(device->cdev));
3908 				dasd_put_device(device);
3909 				return rc;
3910 			}
3911 		}
3912 		list_move_tail(&cqr->devlist, &requeue_queue);
3913 	}
3914 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
3915 
3916 	list_for_each_entry_safe(cqr, n, &requeue_queue, devlist) {
3917 		wait_event(dasd_flush_wq,
3918 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
3919 
3920 		/* mark sleepon requests as ended */
3921 		if (cqr->callback_data == DASD_SLEEPON_START_TAG)
3922 			cqr->callback_data = DASD_SLEEPON_END_TAG;
3923 
3924 		/* remove requests from device and block queue */
3925 		list_del_init(&cqr->devlist);
3926 		while (cqr->refers != NULL) {
3927 			refers = cqr->refers;
3928 			/* remove the request from the block queue */
3929 			list_del(&cqr->blocklist);
3930 			/* free the finished erp request */
3931 			dasd_free_erp_request(cqr, cqr->memdev);
3932 			cqr = refers;
3933 		}
3934 
3935 		/*
3936 		 * requeue requests to blocklayer will only work
3937 		 * for block device requests
3938 		 */
3939 		if (_dasd_requeue_request(cqr))
3940 			continue;
3941 
3942 		if (cqr->block)
3943 			list_del_init(&cqr->blocklist);
3944 		cqr->block->base->discipline->free_cp(
3945 			cqr, (struct request *) cqr->callback_data);
3946 	}
3947 
3948 	/*
3949 	 * if requests remain then they are internal request
3950 	 * and go back to the device queue
3951 	 */
3952 	if (!list_empty(&requeue_queue)) {
3953 		/* move freeze_queue to start of the ccw_queue */
3954 		spin_lock_irq(get_ccwdev_lock(device->cdev));
3955 		list_splice_tail(&requeue_queue, &device->ccw_queue);
3956 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
3957 	}
3958 	/* wake up generic waitqueue for eventually ended sleepon requests */
3959 	wake_up(&generic_waitq);
3960 	return rc;
3961 }
3962 
3963 static void do_requeue_requests(struct work_struct *work)
3964 {
3965 	struct dasd_device *device = container_of(work, struct dasd_device,
3966 						  requeue_requests);
3967 	dasd_generic_requeue_all_requests(device);
3968 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3969 	if (device->block)
3970 		dasd_schedule_block_bh(device->block);
3971 	dasd_put_device(device);
3972 }
3973 
3974 void dasd_schedule_requeue(struct dasd_device *device)
3975 {
3976 	dasd_get_device(device);
3977 	/* queue call to dasd_reload_device to the kernel event daemon. */
3978 	if (!schedule_work(&device->requeue_requests))
3979 		dasd_put_device(device);
3980 }
3981 EXPORT_SYMBOL(dasd_schedule_requeue);
3982 
3983 int dasd_generic_pm_freeze(struct ccw_device *cdev)
3984 {
3985 	struct dasd_device *device = dasd_device_from_cdev(cdev);
3986 
3987 	if (IS_ERR(device))
3988 		return PTR_ERR(device);
3989 
3990 	/* mark device as suspended */
3991 	set_bit(DASD_FLAG_SUSPENDED, &device->flags);
3992 
3993 	if (device->discipline->freeze)
3994 		device->discipline->freeze(device);
3995 
3996 	/* disallow new I/O  */
3997 	dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3998 
3999 	return dasd_generic_requeue_all_requests(device);
4000 }
4001 EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);
4002 
4003 int dasd_generic_restore_device(struct ccw_device *cdev)
4004 {
4005 	struct dasd_device *device = dasd_device_from_cdev(cdev);
4006 	int rc = 0;
4007 
4008 	if (IS_ERR(device))
4009 		return PTR_ERR(device);
4010 
4011 	/* allow new IO again */
4012 	dasd_device_remove_stop_bits(device,
4013 				     (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
4014 
4015 	dasd_schedule_device_bh(device);
4016 
4017 	/*
4018 	 * call discipline restore function
4019 	 * if device is stopped do nothing e.g. for disconnected devices
4020 	 */
4021 	if (device->discipline->restore && !(device->stopped))
4022 		rc = device->discipline->restore(device);
4023 	if (rc || device->stopped)
4024 		/*
4025 		 * if the resume failed for the DASD we put it in
4026 		 * an UNRESUMED stop state
4027 		 */
4028 		device->stopped |= DASD_UNRESUMED_PM;
4029 
4030 	if (device->block) {
4031 		dasd_schedule_block_bh(device->block);
4032 		if (device->block->request_queue)
4033 			blk_mq_run_hw_queues(device->block->request_queue,
4034 					     true);
4035 	}
4036 
4037 	clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
4038 	dasd_put_device(device);
4039 	return 0;
4040 }
4041 EXPORT_SYMBOL_GPL(dasd_generic_restore_device);
4042 
4043 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
4044 						   void *rdc_buffer,
4045 						   int rdc_buffer_size,
4046 						   int magic)
4047 {
4048 	struct dasd_ccw_req *cqr;
4049 	struct ccw1 *ccw;
4050 	unsigned long *idaw;
4051 
4052 	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);
4053 
4054 	if (IS_ERR(cqr)) {
4055 		/* internal error 13 - Allocating the RDC request failed*/
4056 		dev_err(&device->cdev->dev,
4057 			 "An error occurred in the DASD device driver, "
4058 			 "reason=%s\n", "13");
4059 		return cqr;
4060 	}
4061 
4062 	ccw = cqr->cpaddr;
4063 	ccw->cmd_code = CCW_CMD_RDC;
4064 	if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
4065 		idaw = (unsigned long *) (cqr->data);
4066 		ccw->cda = (__u32)(addr_t) idaw;
4067 		ccw->flags = CCW_FLAG_IDA;
4068 		idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
4069 	} else {
4070 		ccw->cda = (__u32)(addr_t) rdc_buffer;
4071 		ccw->flags = 0;
4072 	}
4073 
4074 	ccw->count = rdc_buffer_size;
4075 	cqr->startdev = device;
4076 	cqr->memdev = device;
4077 	cqr->expires = 10*HZ;
4078 	cqr->retries = 256;
4079 	cqr->buildclk = get_tod_clock();
4080 	cqr->status = DASD_CQR_FILLED;
4081 	return cqr;
4082 }
4083 
4084 
4085 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4086 				void *rdc_buffer, int rdc_buffer_size)
4087 {
4088 	int ret;
4089 	struct dasd_ccw_req *cqr;
4090 
4091 	cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
4092 				     magic);
4093 	if (IS_ERR(cqr))
4094 		return PTR_ERR(cqr);
4095 
4096 	ret = dasd_sleep_on(cqr);
4097 	dasd_sfree_request(cqr, cqr->memdev);
4098 	return ret;
4099 }
4100 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4101 
4102 /*
4103  *   In command mode and transport mode we need to look for sense
4104  *   data in different places. The sense data itself is allways
4105  *   an array of 32 bytes, so we can unify the sense data access
4106  *   for both modes.
4107  */
4108 char *dasd_get_sense(struct irb *irb)
4109 {
4110 	struct tsb *tsb = NULL;
4111 	char *sense = NULL;
4112 
4113 	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4114 		if (irb->scsw.tm.tcw)
4115 			tsb = tcw_get_tsb((struct tcw *)(unsigned long)
4116 					  irb->scsw.tm.tcw);
4117 		if (tsb && tsb->length == 64 && tsb->flags)
4118 			switch (tsb->flags & 0x07) {
4119 			case 1:	/* tsa_iostat */
4120 				sense = tsb->tsa.iostat.sense;
4121 				break;
4122 			case 2: /* tsa_ddpc */
4123 				sense = tsb->tsa.ddpc.sense;
4124 				break;
4125 			default:
4126 				/* currently we don't use interrogate data */
4127 				break;
4128 			}
4129 	} else if (irb->esw.esw0.erw.cons) {
4130 		sense = irb->ecw;
4131 	}
4132 	return sense;
4133 }
4134 EXPORT_SYMBOL_GPL(dasd_get_sense);
4135 
4136 void dasd_generic_shutdown(struct ccw_device *cdev)
4137 {
4138 	struct dasd_device *device;
4139 
4140 	device = dasd_device_from_cdev(cdev);
4141 	if (IS_ERR(device))
4142 		return;
4143 
4144 	if (device->block)
4145 		dasd_schedule_block_bh(device->block);
4146 
4147 	dasd_schedule_device_bh(device);
4148 
4149 	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4150 }
4151 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4152 
4153 static int __init dasd_init(void)
4154 {
4155 	int rc;
4156 
4157 	init_waitqueue_head(&dasd_init_waitq);
4158 	init_waitqueue_head(&dasd_flush_wq);
4159 	init_waitqueue_head(&generic_waitq);
4160 	init_waitqueue_head(&shutdown_waitq);
4161 
4162 	/* register 'common' DASD debug area, used for all DBF_XXX calls */
4163 	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4164 	if (dasd_debug_area == NULL) {
4165 		rc = -ENOMEM;
4166 		goto failed;
4167 	}
4168 	debug_register_view(dasd_debug_area, &debug_sprintf_view);
4169 	debug_set_level(dasd_debug_area, DBF_WARNING);
4170 
4171 	DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4172 
4173 	dasd_diag_discipline_pointer = NULL;
4174 
4175 	dasd_statistics_createroot();
4176 
4177 	rc = dasd_devmap_init();
4178 	if (rc)
4179 		goto failed;
4180 	rc = dasd_gendisk_init();
4181 	if (rc)
4182 		goto failed;
4183 	rc = dasd_parse();
4184 	if (rc)
4185 		goto failed;
4186 	rc = dasd_eer_init();
4187 	if (rc)
4188 		goto failed;
4189 #ifdef CONFIG_PROC_FS
4190 	rc = dasd_proc_init();
4191 	if (rc)
4192 		goto failed;
4193 #endif
4194 
4195 	return 0;
4196 failed:
4197 	pr_info("The DASD device driver could not be initialized\n");
4198 	dasd_exit();
4199 	return rc;
4200 }
4201 
4202 module_init(dasd_init);
4203 module_exit(dasd_exit);
4204