1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4  *		    Horst Hummel <Horst.Hummel@de.ibm.com>
5  *		    Carsten Otte <Cotte@de.ibm.com>
6  *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
7  * Bugreports.to..: <Linux390@de.ibm.com>
8  * Copyright IBM Corp. 1999, 2009
9  */
10 
11 #define KMSG_COMPONENT "dasd"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13 
14 #include <linux/kmod.h>
15 #include <linux/init.h>
16 #include <linux/interrupt.h>
17 #include <linux/ctype.h>
18 #include <linux/major.h>
19 #include <linux/slab.h>
20 #include <linux/hdreg.h>
21 #include <linux/async.h>
22 #include <linux/mutex.h>
23 #include <linux/debugfs.h>
24 #include <linux/seq_file.h>
25 #include <linux/vmalloc.h>
26 
27 #include <asm/ccwdev.h>
28 #include <asm/ebcdic.h>
29 #include <asm/idals.h>
30 #include <asm/itcw.h>
31 #include <asm/diag.h>
32 
33 /* This is ugly... */
34 #define PRINTK_HEADER "dasd:"
35 
36 #include "dasd_int.h"
37 /*
38  * SECTION: Constant definitions to be used within this file
39  */
40 #define DASD_CHANQ_MAX_SIZE 4
41 
42 #define DASD_DIAG_MOD		"dasd_diag_mod"
43 
44 /*
45  * SECTION: exported variables of dasd.c
46  */
47 debug_info_t *dasd_debug_area;
48 EXPORT_SYMBOL(dasd_debug_area);
49 static struct dentry *dasd_debugfs_root_entry;
50 struct dasd_discipline *dasd_diag_discipline_pointer;
51 EXPORT_SYMBOL(dasd_diag_discipline_pointer);
52 void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
53 
54 MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
55 MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
56 		   " Copyright IBM Corp. 2000");
57 MODULE_LICENSE("GPL");
58 
59 /*
60  * SECTION: prototypes for static functions of dasd.c
61  */
62 static int dasd_flush_block_queue(struct dasd_block *);
63 static void dasd_device_tasklet(unsigned long);
64 static void dasd_block_tasklet(unsigned long);
65 static void do_kick_device(struct work_struct *);
66 static void do_reload_device(struct work_struct *);
67 static void do_requeue_requests(struct work_struct *);
68 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
69 static void dasd_device_timeout(struct timer_list *);
70 static void dasd_block_timeout(struct timer_list *);
71 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
72 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
73 static void dasd_profile_exit(struct dasd_profile *);
74 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
75 static void dasd_hosts_exit(struct dasd_device *);
76 static int dasd_handle_autoquiesce(struct dasd_device *, struct dasd_ccw_req *,
77 				   unsigned int);
78 /*
79  * SECTION: Operations on the device structure.
80  */
81 static wait_queue_head_t dasd_init_waitq;
82 static wait_queue_head_t dasd_flush_wq;
83 static wait_queue_head_t generic_waitq;
84 static wait_queue_head_t shutdown_waitq;
85 
86 /*
87  * Allocate memory for a new device structure.
88  */
dasd_alloc_device(void)89 struct dasd_device *dasd_alloc_device(void)
90 {
91 	struct dasd_device *device;
92 
93 	device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
94 	if (!device)
95 		return ERR_PTR(-ENOMEM);
96 
97 	/* Get two pages for normal block device operations. */
98 	device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
99 	if (!device->ccw_mem) {
100 		kfree(device);
101 		return ERR_PTR(-ENOMEM);
102 	}
103 	/* Get one page for error recovery. */
104 	device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
105 	if (!device->erp_mem) {
106 		free_pages((unsigned long) device->ccw_mem, 1);
107 		kfree(device);
108 		return ERR_PTR(-ENOMEM);
109 	}
110 	/* Get two pages for ese format. */
111 	device->ese_mem = (void *)__get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
112 	if (!device->ese_mem) {
113 		free_page((unsigned long) device->erp_mem);
114 		free_pages((unsigned long) device->ccw_mem, 1);
115 		kfree(device);
116 		return ERR_PTR(-ENOMEM);
117 	}
118 
119 	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
120 	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
121 	dasd_init_chunklist(&device->ese_chunks, device->ese_mem, PAGE_SIZE * 2);
122 	spin_lock_init(&device->mem_lock);
123 	atomic_set(&device->tasklet_scheduled, 0);
124 	tasklet_init(&device->tasklet, dasd_device_tasklet,
125 		     (unsigned long) device);
126 	INIT_LIST_HEAD(&device->ccw_queue);
127 	timer_setup(&device->timer, dasd_device_timeout, 0);
128 	INIT_WORK(&device->kick_work, do_kick_device);
129 	INIT_WORK(&device->reload_device, do_reload_device);
130 	INIT_WORK(&device->requeue_requests, do_requeue_requests);
131 	device->state = DASD_STATE_NEW;
132 	device->target = DASD_STATE_NEW;
133 	mutex_init(&device->state_mutex);
134 	spin_lock_init(&device->profile.lock);
135 	return device;
136 }
137 
138 /*
139  * Free memory of a device structure.
140  */
dasd_free_device(struct dasd_device * device)141 void dasd_free_device(struct dasd_device *device)
142 {
143 	kfree(device->private);
144 	free_pages((unsigned long) device->ese_mem, 1);
145 	free_page((unsigned long) device->erp_mem);
146 	free_pages((unsigned long) device->ccw_mem, 1);
147 	kfree(device);
148 }
149 
150 /*
151  * Allocate memory for a new device structure.
152  */
dasd_alloc_block(void)153 struct dasd_block *dasd_alloc_block(void)
154 {
155 	struct dasd_block *block;
156 
157 	block = kzalloc(sizeof(*block), GFP_ATOMIC);
158 	if (!block)
159 		return ERR_PTR(-ENOMEM);
160 	/* open_count = 0 means device online but not in use */
161 	atomic_set(&block->open_count, -1);
162 
163 	atomic_set(&block->tasklet_scheduled, 0);
164 	tasklet_init(&block->tasklet, dasd_block_tasklet,
165 		     (unsigned long) block);
166 	INIT_LIST_HEAD(&block->ccw_queue);
167 	spin_lock_init(&block->queue_lock);
168 	INIT_LIST_HEAD(&block->format_list);
169 	spin_lock_init(&block->format_lock);
170 	timer_setup(&block->timer, dasd_block_timeout, 0);
171 	spin_lock_init(&block->profile.lock);
172 
173 	return block;
174 }
175 EXPORT_SYMBOL_GPL(dasd_alloc_block);
176 
177 /*
178  * Free memory of a device structure.
179  */
dasd_free_block(struct dasd_block * block)180 void dasd_free_block(struct dasd_block *block)
181 {
182 	kfree(block);
183 }
184 EXPORT_SYMBOL_GPL(dasd_free_block);
185 
186 /*
187  * Make a new device known to the system.
188  */
dasd_state_new_to_known(struct dasd_device * device)189 static int dasd_state_new_to_known(struct dasd_device *device)
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 	device->state = DASD_STATE_KNOWN;
197 	return 0;
198 }
199 
200 /*
201  * Let the system forget about a device.
202  */
dasd_state_known_to_new(struct dasd_device * device)203 static int dasd_state_known_to_new(struct dasd_device *device)
204 {
205 	/* Disable extended error reporting for this device. */
206 	dasd_eer_disable(device);
207 	device->state = DASD_STATE_NEW;
208 
209 	/* Give up reference we took in dasd_state_new_to_known. */
210 	dasd_put_device(device);
211 	return 0;
212 }
213 
dasd_debugfs_setup(const char * name,struct dentry * base_dentry)214 static struct dentry *dasd_debugfs_setup(const char *name,
215 					 struct dentry *base_dentry)
216 {
217 	struct dentry *pde;
218 
219 	if (!base_dentry)
220 		return NULL;
221 	pde = debugfs_create_dir(name, base_dentry);
222 	if (!pde || IS_ERR(pde))
223 		return NULL;
224 	return pde;
225 }
226 
227 /*
228  * Request the irq line for the device.
229  */
dasd_state_known_to_basic(struct dasd_device * device)230 static int dasd_state_known_to_basic(struct dasd_device *device)
231 {
232 	struct dasd_block *block = device->block;
233 	int rc = 0;
234 
235 	/* Allocate and register gendisk structure. */
236 	if (block) {
237 		rc = dasd_gendisk_alloc(block);
238 		if (rc)
239 			return rc;
240 		block->debugfs_dentry =
241 			dasd_debugfs_setup(block->gdp->disk_name,
242 					   dasd_debugfs_root_entry);
243 		dasd_profile_init(&block->profile, block->debugfs_dentry);
244 		if (dasd_global_profile_level == DASD_PROFILE_ON)
245 			dasd_profile_on(&device->block->profile);
246 	}
247 	device->debugfs_dentry =
248 		dasd_debugfs_setup(dev_name(&device->cdev->dev),
249 				   dasd_debugfs_root_entry);
250 	dasd_profile_init(&device->profile, device->debugfs_dentry);
251 	dasd_hosts_init(device->debugfs_dentry, device);
252 
253 	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
254 	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
255 					    8 * sizeof(long));
256 	debug_register_view(device->debug_area, &debug_sprintf_view);
257 	debug_set_level(device->debug_area, DBF_WARNING);
258 	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
259 
260 	device->state = DASD_STATE_BASIC;
261 
262 	return rc;
263 }
264 
265 /*
266  * Release the irq line for the device. Terminate any running i/o.
267  */
dasd_state_basic_to_known(struct dasd_device * device)268 static int dasd_state_basic_to_known(struct dasd_device *device)
269 {
270 	int rc;
271 
272 	if (device->discipline->basic_to_known) {
273 		rc = device->discipline->basic_to_known(device);
274 		if (rc)
275 			return rc;
276 	}
277 
278 	if (device->block) {
279 		dasd_profile_exit(&device->block->profile);
280 		debugfs_remove(device->block->debugfs_dentry);
281 		dasd_gendisk_free(device->block);
282 		dasd_block_clear_timer(device->block);
283 	}
284 	rc = dasd_flush_device_queue(device);
285 	if (rc)
286 		return rc;
287 	dasd_device_clear_timer(device);
288 	dasd_profile_exit(&device->profile);
289 	dasd_hosts_exit(device);
290 	debugfs_remove(device->debugfs_dentry);
291 	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
292 	if (device->debug_area != NULL) {
293 		debug_unregister(device->debug_area);
294 		device->debug_area = NULL;
295 	}
296 	device->state = DASD_STATE_KNOWN;
297 	return 0;
298 }
299 
300 /*
301  * Do the initial analysis. The do_analysis function may return
302  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
303  * until the discipline decides to continue the startup sequence
304  * by calling the function dasd_change_state. The eckd disciplines
305  * uses this to start a ccw that detects the format. The completion
306  * interrupt for this detection ccw uses the kernel event daemon to
307  * trigger the call to dasd_change_state. All this is done in the
308  * discipline code, see dasd_eckd.c.
309  * After the analysis ccw is done (do_analysis returned 0) the block
310  * device is setup.
311  * In case the analysis returns an error, the device setup is stopped
312  * (a fake disk was already added to allow formatting).
313  */
dasd_state_basic_to_ready(struct dasd_device * device)314 static int dasd_state_basic_to_ready(struct dasd_device *device)
315 {
316 	int rc;
317 	struct dasd_block *block;
318 	struct gendisk *disk;
319 
320 	rc = 0;
321 	block = device->block;
322 	/* make disk known with correct capacity */
323 	if (block) {
324 		if (block->base->discipline->do_analysis != NULL)
325 			rc = block->base->discipline->do_analysis(block);
326 		if (rc) {
327 			if (rc != -EAGAIN) {
328 				device->state = DASD_STATE_UNFMT;
329 				disk = device->block->gdp;
330 				kobject_uevent(&disk_to_dev(disk)->kobj,
331 					       KOBJ_CHANGE);
332 				goto out;
333 			}
334 			return rc;
335 		}
336 		if (device->discipline->setup_blk_queue)
337 			device->discipline->setup_blk_queue(block);
338 		set_capacity(block->gdp,
339 			     block->blocks << block->s2b_shift);
340 		device->state = DASD_STATE_READY;
341 		rc = dasd_scan_partitions(block);
342 		if (rc) {
343 			device->state = DASD_STATE_BASIC;
344 			return rc;
345 		}
346 	} else {
347 		device->state = DASD_STATE_READY;
348 	}
349 out:
350 	if (device->discipline->basic_to_ready)
351 		rc = device->discipline->basic_to_ready(device);
352 	return rc;
353 }
354 
355 static inline
_wait_for_empty_queues(struct dasd_device * device)356 int _wait_for_empty_queues(struct dasd_device *device)
357 {
358 	if (device->block)
359 		return list_empty(&device->ccw_queue) &&
360 			list_empty(&device->block->ccw_queue);
361 	else
362 		return list_empty(&device->ccw_queue);
363 }
364 
365 /*
366  * Remove device from block device layer. Destroy dirty buffers.
367  * Forget format information. Check if the target level is basic
368  * and if it is create fake disk for formatting.
369  */
dasd_state_ready_to_basic(struct dasd_device * device)370 static int dasd_state_ready_to_basic(struct dasd_device *device)
371 {
372 	int rc;
373 
374 	device->state = DASD_STATE_BASIC;
375 	if (device->block) {
376 		struct dasd_block *block = device->block;
377 		rc = dasd_flush_block_queue(block);
378 		if (rc) {
379 			device->state = DASD_STATE_READY;
380 			return rc;
381 		}
382 		dasd_destroy_partitions(block);
383 		block->blocks = 0;
384 		block->bp_block = 0;
385 		block->s2b_shift = 0;
386 	}
387 	return 0;
388 }
389 
390 /*
391  * Back to basic.
392  */
dasd_state_unfmt_to_basic(struct dasd_device * device)393 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
394 {
395 	device->state = DASD_STATE_BASIC;
396 	return 0;
397 }
398 
399 /*
400  * Make the device online and schedule the bottom half to start
401  * the requeueing of requests from the linux request queue to the
402  * ccw queue.
403  */
404 static int
dasd_state_ready_to_online(struct dasd_device * device)405 dasd_state_ready_to_online(struct dasd_device * device)
406 {
407 	device->state = DASD_STATE_ONLINE;
408 	if (device->block) {
409 		dasd_schedule_block_bh(device->block);
410 		if ((device->features & DASD_FEATURE_USERAW)) {
411 			kobject_uevent(&disk_to_dev(device->block->gdp)->kobj,
412 					KOBJ_CHANGE);
413 			return 0;
414 		}
415 		disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
416 	}
417 	return 0;
418 }
419 
420 /*
421  * Stop the requeueing of requests again.
422  */
dasd_state_online_to_ready(struct dasd_device * device)423 static int dasd_state_online_to_ready(struct dasd_device *device)
424 {
425 	int rc;
426 
427 	if (device->discipline->online_to_ready) {
428 		rc = device->discipline->online_to_ready(device);
429 		if (rc)
430 			return rc;
431 	}
432 
433 	device->state = DASD_STATE_READY;
434 	if (device->block && !(device->features & DASD_FEATURE_USERAW))
435 		disk_uevent(device->block->bdev->bd_disk, KOBJ_CHANGE);
436 	return 0;
437 }
438 
439 /*
440  * Device startup state changes.
441  */
dasd_increase_state(struct dasd_device * device)442 static int dasd_increase_state(struct dasd_device *device)
443 {
444 	int rc;
445 
446 	rc = 0;
447 	if (device->state == DASD_STATE_NEW &&
448 	    device->target >= DASD_STATE_KNOWN)
449 		rc = dasd_state_new_to_known(device);
450 
451 	if (!rc &&
452 	    device->state == DASD_STATE_KNOWN &&
453 	    device->target >= DASD_STATE_BASIC)
454 		rc = dasd_state_known_to_basic(device);
455 
456 	if (!rc &&
457 	    device->state == DASD_STATE_BASIC &&
458 	    device->target >= DASD_STATE_READY)
459 		rc = dasd_state_basic_to_ready(device);
460 
461 	if (!rc &&
462 	    device->state == DASD_STATE_UNFMT &&
463 	    device->target > DASD_STATE_UNFMT)
464 		rc = -EPERM;
465 
466 	if (!rc &&
467 	    device->state == DASD_STATE_READY &&
468 	    device->target >= DASD_STATE_ONLINE)
469 		rc = dasd_state_ready_to_online(device);
470 
471 	return rc;
472 }
473 
474 /*
475  * Device shutdown state changes.
476  */
dasd_decrease_state(struct dasd_device * device)477 static int dasd_decrease_state(struct dasd_device *device)
478 {
479 	int rc;
480 
481 	rc = 0;
482 	if (device->state == DASD_STATE_ONLINE &&
483 	    device->target <= DASD_STATE_READY)
484 		rc = dasd_state_online_to_ready(device);
485 
486 	if (!rc &&
487 	    device->state == DASD_STATE_READY &&
488 	    device->target <= DASD_STATE_BASIC)
489 		rc = dasd_state_ready_to_basic(device);
490 
491 	if (!rc &&
492 	    device->state == DASD_STATE_UNFMT &&
493 	    device->target <= DASD_STATE_BASIC)
494 		rc = dasd_state_unfmt_to_basic(device);
495 
496 	if (!rc &&
497 	    device->state == DASD_STATE_BASIC &&
498 	    device->target <= DASD_STATE_KNOWN)
499 		rc = dasd_state_basic_to_known(device);
500 
501 	if (!rc &&
502 	    device->state == DASD_STATE_KNOWN &&
503 	    device->target <= DASD_STATE_NEW)
504 		rc = dasd_state_known_to_new(device);
505 
506 	return rc;
507 }
508 
509 /*
510  * This is the main startup/shutdown routine.
511  */
dasd_change_state(struct dasd_device * device)512 static void dasd_change_state(struct dasd_device *device)
513 {
514 	int rc;
515 
516 	if (device->state == device->target)
517 		/* Already where we want to go today... */
518 		return;
519 	if (device->state < device->target)
520 		rc = dasd_increase_state(device);
521 	else
522 		rc = dasd_decrease_state(device);
523 	if (rc == -EAGAIN)
524 		return;
525 	if (rc)
526 		device->target = device->state;
527 
528 	/* let user-space know that the device status changed */
529 	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
530 
531 	if (device->state == device->target)
532 		wake_up(&dasd_init_waitq);
533 }
534 
535 /*
536  * Kick starter for devices that did not complete the startup/shutdown
537  * procedure or were sleeping because of a pending state.
538  * dasd_kick_device will schedule a call do do_kick_device to the kernel
539  * event daemon.
540  */
do_kick_device(struct work_struct * work)541 static void do_kick_device(struct work_struct *work)
542 {
543 	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
544 	mutex_lock(&device->state_mutex);
545 	dasd_change_state(device);
546 	mutex_unlock(&device->state_mutex);
547 	dasd_schedule_device_bh(device);
548 	dasd_put_device(device);
549 }
550 
dasd_kick_device(struct dasd_device * device)551 void dasd_kick_device(struct dasd_device *device)
552 {
553 	dasd_get_device(device);
554 	/* queue call to dasd_kick_device to the kernel event daemon. */
555 	if (!schedule_work(&device->kick_work))
556 		dasd_put_device(device);
557 }
558 EXPORT_SYMBOL(dasd_kick_device);
559 
560 /*
561  * dasd_reload_device will schedule a call do do_reload_device to the kernel
562  * event daemon.
563  */
do_reload_device(struct work_struct * work)564 static void do_reload_device(struct work_struct *work)
565 {
566 	struct dasd_device *device = container_of(work, struct dasd_device,
567 						  reload_device);
568 	device->discipline->reload(device);
569 	dasd_put_device(device);
570 }
571 
dasd_reload_device(struct dasd_device * device)572 void dasd_reload_device(struct dasd_device *device)
573 {
574 	dasd_get_device(device);
575 	/* queue call to dasd_reload_device to the kernel event daemon. */
576 	if (!schedule_work(&device->reload_device))
577 		dasd_put_device(device);
578 }
579 EXPORT_SYMBOL(dasd_reload_device);
580 
581 /*
582  * Set the target state for a device and starts the state change.
583  */
dasd_set_target_state(struct dasd_device * device,int target)584 void dasd_set_target_state(struct dasd_device *device, int target)
585 {
586 	dasd_get_device(device);
587 	mutex_lock(&device->state_mutex);
588 	/* If we are in probeonly mode stop at DASD_STATE_READY. */
589 	if (dasd_probeonly && target > DASD_STATE_READY)
590 		target = DASD_STATE_READY;
591 	if (device->target != target) {
592 		if (device->state == target)
593 			wake_up(&dasd_init_waitq);
594 		device->target = target;
595 	}
596 	if (device->state != device->target)
597 		dasd_change_state(device);
598 	mutex_unlock(&device->state_mutex);
599 	dasd_put_device(device);
600 }
601 
602 /*
603  * Enable devices with device numbers in [from..to].
604  */
_wait_for_device(struct dasd_device * device)605 static inline int _wait_for_device(struct dasd_device *device)
606 {
607 	return (device->state == device->target);
608 }
609 
dasd_enable_device(struct dasd_device * device)610 void dasd_enable_device(struct dasd_device *device)
611 {
612 	dasd_set_target_state(device, DASD_STATE_ONLINE);
613 	if (device->state <= DASD_STATE_KNOWN)
614 		/* No discipline for device found. */
615 		dasd_set_target_state(device, DASD_STATE_NEW);
616 	/* Now wait for the devices to come up. */
617 	wait_event(dasd_init_waitq, _wait_for_device(device));
618 
619 	dasd_reload_device(device);
620 	if (device->discipline->kick_validate)
621 		device->discipline->kick_validate(device);
622 }
623 EXPORT_SYMBOL(dasd_enable_device);
624 
625 /*
626  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
627  */
628 
629 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
630 
631 #ifdef CONFIG_DASD_PROFILE
632 struct dasd_profile dasd_global_profile = {
633 	.lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
634 };
635 static struct dentry *dasd_debugfs_global_entry;
636 
637 /*
638  * Add profiling information for cqr before execution.
639  */
dasd_profile_start(struct dasd_block * block,struct dasd_ccw_req * cqr,struct request * req)640 static void dasd_profile_start(struct dasd_block *block,
641 			       struct dasd_ccw_req *cqr,
642 			       struct request *req)
643 {
644 	struct list_head *l;
645 	unsigned int counter;
646 	struct dasd_device *device;
647 
648 	/* count the length of the chanq for statistics */
649 	counter = 0;
650 	if (dasd_global_profile_level || block->profile.data)
651 		list_for_each(l, &block->ccw_queue)
652 			if (++counter >= 31)
653 				break;
654 
655 	spin_lock(&dasd_global_profile.lock);
656 	if (dasd_global_profile.data) {
657 		dasd_global_profile.data->dasd_io_nr_req[counter]++;
658 		if (rq_data_dir(req) == READ)
659 			dasd_global_profile.data->dasd_read_nr_req[counter]++;
660 	}
661 	spin_unlock(&dasd_global_profile.lock);
662 
663 	spin_lock(&block->profile.lock);
664 	if (block->profile.data) {
665 		block->profile.data->dasd_io_nr_req[counter]++;
666 		if (rq_data_dir(req) == READ)
667 			block->profile.data->dasd_read_nr_req[counter]++;
668 	}
669 	spin_unlock(&block->profile.lock);
670 
671 	/*
672 	 * We count the request for the start device, even though it may run on
673 	 * some other device due to error recovery. This way we make sure that
674 	 * we count each request only once.
675 	 */
676 	device = cqr->startdev;
677 	if (!device->profile.data)
678 		return;
679 
680 	spin_lock(get_ccwdev_lock(device->cdev));
681 	counter = 1; /* request is not yet queued on the start device */
682 	list_for_each(l, &device->ccw_queue)
683 		if (++counter >= 31)
684 			break;
685 	spin_unlock(get_ccwdev_lock(device->cdev));
686 
687 	spin_lock(&device->profile.lock);
688 	device->profile.data->dasd_io_nr_req[counter]++;
689 	if (rq_data_dir(req) == READ)
690 		device->profile.data->dasd_read_nr_req[counter]++;
691 	spin_unlock(&device->profile.lock);
692 }
693 
694 /*
695  * Add profiling information for cqr after execution.
696  */
697 
698 #define dasd_profile_counter(value, index)			   \
699 {								   \
700 	for (index = 0; index < 31 && value >> (2+index); index++) \
701 		;						   \
702 }
703 
dasd_profile_end_add_data(struct dasd_profile_info * data,int is_alias,int is_tpm,int is_read,long sectors,int sectors_ind,int tottime_ind,int tottimeps_ind,int strtime_ind,int irqtime_ind,int irqtimeps_ind,int endtime_ind)704 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
705 				      int is_alias,
706 				      int is_tpm,
707 				      int is_read,
708 				      long sectors,
709 				      int sectors_ind,
710 				      int tottime_ind,
711 				      int tottimeps_ind,
712 				      int strtime_ind,
713 				      int irqtime_ind,
714 				      int irqtimeps_ind,
715 				      int endtime_ind)
716 {
717 	/* in case of an overflow, reset the whole profile */
718 	if (data->dasd_io_reqs == UINT_MAX) {
719 			memset(data, 0, sizeof(*data));
720 			ktime_get_real_ts64(&data->starttod);
721 	}
722 	data->dasd_io_reqs++;
723 	data->dasd_io_sects += sectors;
724 	if (is_alias)
725 		data->dasd_io_alias++;
726 	if (is_tpm)
727 		data->dasd_io_tpm++;
728 
729 	data->dasd_io_secs[sectors_ind]++;
730 	data->dasd_io_times[tottime_ind]++;
731 	data->dasd_io_timps[tottimeps_ind]++;
732 	data->dasd_io_time1[strtime_ind]++;
733 	data->dasd_io_time2[irqtime_ind]++;
734 	data->dasd_io_time2ps[irqtimeps_ind]++;
735 	data->dasd_io_time3[endtime_ind]++;
736 
737 	if (is_read) {
738 		data->dasd_read_reqs++;
739 		data->dasd_read_sects += sectors;
740 		if (is_alias)
741 			data->dasd_read_alias++;
742 		if (is_tpm)
743 			data->dasd_read_tpm++;
744 		data->dasd_read_secs[sectors_ind]++;
745 		data->dasd_read_times[tottime_ind]++;
746 		data->dasd_read_time1[strtime_ind]++;
747 		data->dasd_read_time2[irqtime_ind]++;
748 		data->dasd_read_time3[endtime_ind]++;
749 	}
750 }
751 
dasd_profile_end(struct dasd_block * block,struct dasd_ccw_req * cqr,struct request * req)752 static void dasd_profile_end(struct dasd_block *block,
753 			     struct dasd_ccw_req *cqr,
754 			     struct request *req)
755 {
756 	unsigned long strtime, irqtime, endtime, tottime;
757 	unsigned long tottimeps, sectors;
758 	struct dasd_device *device;
759 	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
760 	int irqtime_ind, irqtimeps_ind, endtime_ind;
761 	struct dasd_profile_info *data;
762 
763 	device = cqr->startdev;
764 	if (!(dasd_global_profile_level ||
765 	      block->profile.data ||
766 	      device->profile.data))
767 		return;
768 
769 	sectors = blk_rq_sectors(req);
770 	if (!cqr->buildclk || !cqr->startclk ||
771 	    !cqr->stopclk || !cqr->endclk ||
772 	    !sectors)
773 		return;
774 
775 	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
776 	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
777 	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
778 	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
779 	tottimeps = tottime / sectors;
780 
781 	dasd_profile_counter(sectors, sectors_ind);
782 	dasd_profile_counter(tottime, tottime_ind);
783 	dasd_profile_counter(tottimeps, tottimeps_ind);
784 	dasd_profile_counter(strtime, strtime_ind);
785 	dasd_profile_counter(irqtime, irqtime_ind);
786 	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
787 	dasd_profile_counter(endtime, endtime_ind);
788 
789 	spin_lock(&dasd_global_profile.lock);
790 	if (dasd_global_profile.data) {
791 		data = dasd_global_profile.data;
792 		data->dasd_sum_times += tottime;
793 		data->dasd_sum_time_str += strtime;
794 		data->dasd_sum_time_irq += irqtime;
795 		data->dasd_sum_time_end += endtime;
796 		dasd_profile_end_add_data(dasd_global_profile.data,
797 					  cqr->startdev != block->base,
798 					  cqr->cpmode == 1,
799 					  rq_data_dir(req) == READ,
800 					  sectors, sectors_ind, tottime_ind,
801 					  tottimeps_ind, strtime_ind,
802 					  irqtime_ind, irqtimeps_ind,
803 					  endtime_ind);
804 	}
805 	spin_unlock(&dasd_global_profile.lock);
806 
807 	spin_lock(&block->profile.lock);
808 	if (block->profile.data) {
809 		data = block->profile.data;
810 		data->dasd_sum_times += tottime;
811 		data->dasd_sum_time_str += strtime;
812 		data->dasd_sum_time_irq += irqtime;
813 		data->dasd_sum_time_end += endtime;
814 		dasd_profile_end_add_data(block->profile.data,
815 					  cqr->startdev != block->base,
816 					  cqr->cpmode == 1,
817 					  rq_data_dir(req) == READ,
818 					  sectors, sectors_ind, tottime_ind,
819 					  tottimeps_ind, strtime_ind,
820 					  irqtime_ind, irqtimeps_ind,
821 					  endtime_ind);
822 	}
823 	spin_unlock(&block->profile.lock);
824 
825 	spin_lock(&device->profile.lock);
826 	if (device->profile.data) {
827 		data = device->profile.data;
828 		data->dasd_sum_times += tottime;
829 		data->dasd_sum_time_str += strtime;
830 		data->dasd_sum_time_irq += irqtime;
831 		data->dasd_sum_time_end += endtime;
832 		dasd_profile_end_add_data(device->profile.data,
833 					  cqr->startdev != block->base,
834 					  cqr->cpmode == 1,
835 					  rq_data_dir(req) == READ,
836 					  sectors, sectors_ind, tottime_ind,
837 					  tottimeps_ind, strtime_ind,
838 					  irqtime_ind, irqtimeps_ind,
839 					  endtime_ind);
840 	}
841 	spin_unlock(&device->profile.lock);
842 }
843 
dasd_profile_reset(struct dasd_profile * profile)844 void dasd_profile_reset(struct dasd_profile *profile)
845 {
846 	struct dasd_profile_info *data;
847 
848 	spin_lock_bh(&profile->lock);
849 	data = profile->data;
850 	if (!data) {
851 		spin_unlock_bh(&profile->lock);
852 		return;
853 	}
854 	memset(data, 0, sizeof(*data));
855 	ktime_get_real_ts64(&data->starttod);
856 	spin_unlock_bh(&profile->lock);
857 }
858 
dasd_profile_on(struct dasd_profile * profile)859 int dasd_profile_on(struct dasd_profile *profile)
860 {
861 	struct dasd_profile_info *data;
862 
863 	data = kzalloc(sizeof(*data), GFP_KERNEL);
864 	if (!data)
865 		return -ENOMEM;
866 	spin_lock_bh(&profile->lock);
867 	if (profile->data) {
868 		spin_unlock_bh(&profile->lock);
869 		kfree(data);
870 		return 0;
871 	}
872 	ktime_get_real_ts64(&data->starttod);
873 	profile->data = data;
874 	spin_unlock_bh(&profile->lock);
875 	return 0;
876 }
877 
dasd_profile_off(struct dasd_profile * profile)878 void dasd_profile_off(struct dasd_profile *profile)
879 {
880 	spin_lock_bh(&profile->lock);
881 	kfree(profile->data);
882 	profile->data = NULL;
883 	spin_unlock_bh(&profile->lock);
884 }
885 
dasd_get_user_string(const char __user * user_buf,size_t user_len)886 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
887 {
888 	char *buffer;
889 
890 	buffer = vmalloc(user_len + 1);
891 	if (buffer == NULL)
892 		return ERR_PTR(-ENOMEM);
893 	if (copy_from_user(buffer, user_buf, user_len) != 0) {
894 		vfree(buffer);
895 		return ERR_PTR(-EFAULT);
896 	}
897 	/* got the string, now strip linefeed. */
898 	if (buffer[user_len - 1] == '\n')
899 		buffer[user_len - 1] = 0;
900 	else
901 		buffer[user_len] = 0;
902 	return buffer;
903 }
904 
dasd_stats_write(struct file * file,const char __user * user_buf,size_t user_len,loff_t * pos)905 static ssize_t dasd_stats_write(struct file *file,
906 				const char __user *user_buf,
907 				size_t user_len, loff_t *pos)
908 {
909 	char *buffer, *str;
910 	int rc;
911 	struct seq_file *m = (struct seq_file *)file->private_data;
912 	struct dasd_profile *prof = m->private;
913 
914 	if (user_len > 65536)
915 		user_len = 65536;
916 	buffer = dasd_get_user_string(user_buf, user_len);
917 	if (IS_ERR(buffer))
918 		return PTR_ERR(buffer);
919 
920 	str = skip_spaces(buffer);
921 	rc = user_len;
922 	if (strncmp(str, "reset", 5) == 0) {
923 		dasd_profile_reset(prof);
924 	} else if (strncmp(str, "on", 2) == 0) {
925 		rc = dasd_profile_on(prof);
926 		if (rc)
927 			goto out;
928 		rc = user_len;
929 		if (prof == &dasd_global_profile) {
930 			dasd_profile_reset(prof);
931 			dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
932 		}
933 	} else if (strncmp(str, "off", 3) == 0) {
934 		if (prof == &dasd_global_profile)
935 			dasd_global_profile_level = DASD_PROFILE_OFF;
936 		dasd_profile_off(prof);
937 	} else
938 		rc = -EINVAL;
939 out:
940 	vfree(buffer);
941 	return rc;
942 }
943 
dasd_stats_array(struct seq_file * m,unsigned int * array)944 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
945 {
946 	int i;
947 
948 	for (i = 0; i < 32; i++)
949 		seq_printf(m, "%u ", array[i]);
950 	seq_putc(m, '\n');
951 }
952 
dasd_stats_seq_print(struct seq_file * m,struct dasd_profile_info * data)953 static void dasd_stats_seq_print(struct seq_file *m,
954 				 struct dasd_profile_info *data)
955 {
956 	seq_printf(m, "start_time %lld.%09ld\n",
957 		   (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
958 	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
959 	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
960 	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
961 	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
962 	seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
963 		   data->dasd_sum_times / data->dasd_io_reqs : 0UL);
964 	seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
965 		   data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
966 	seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
967 		   data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
968 	seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
969 		   data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
970 	seq_puts(m, "histogram_sectors ");
971 	dasd_stats_array(m, data->dasd_io_secs);
972 	seq_puts(m, "histogram_io_times ");
973 	dasd_stats_array(m, data->dasd_io_times);
974 	seq_puts(m, "histogram_io_times_weighted ");
975 	dasd_stats_array(m, data->dasd_io_timps);
976 	seq_puts(m, "histogram_time_build_to_ssch ");
977 	dasd_stats_array(m, data->dasd_io_time1);
978 	seq_puts(m, "histogram_time_ssch_to_irq ");
979 	dasd_stats_array(m, data->dasd_io_time2);
980 	seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
981 	dasd_stats_array(m, data->dasd_io_time2ps);
982 	seq_puts(m, "histogram_time_irq_to_end ");
983 	dasd_stats_array(m, data->dasd_io_time3);
984 	seq_puts(m, "histogram_ccw_queue_length ");
985 	dasd_stats_array(m, data->dasd_io_nr_req);
986 	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
987 	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
988 	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
989 	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
990 	seq_puts(m, "histogram_read_sectors ");
991 	dasd_stats_array(m, data->dasd_read_secs);
992 	seq_puts(m, "histogram_read_times ");
993 	dasd_stats_array(m, data->dasd_read_times);
994 	seq_puts(m, "histogram_read_time_build_to_ssch ");
995 	dasd_stats_array(m, data->dasd_read_time1);
996 	seq_puts(m, "histogram_read_time_ssch_to_irq ");
997 	dasd_stats_array(m, data->dasd_read_time2);
998 	seq_puts(m, "histogram_read_time_irq_to_end ");
999 	dasd_stats_array(m, data->dasd_read_time3);
1000 	seq_puts(m, "histogram_read_ccw_queue_length ");
1001 	dasd_stats_array(m, data->dasd_read_nr_req);
1002 }
1003 
dasd_stats_show(struct seq_file * m,void * v)1004 static int dasd_stats_show(struct seq_file *m, void *v)
1005 {
1006 	struct dasd_profile *profile;
1007 	struct dasd_profile_info *data;
1008 
1009 	profile = m->private;
1010 	spin_lock_bh(&profile->lock);
1011 	data = profile->data;
1012 	if (!data) {
1013 		spin_unlock_bh(&profile->lock);
1014 		seq_puts(m, "disabled\n");
1015 		return 0;
1016 	}
1017 	dasd_stats_seq_print(m, data);
1018 	spin_unlock_bh(&profile->lock);
1019 	return 0;
1020 }
1021 
dasd_stats_open(struct inode * inode,struct file * file)1022 static int dasd_stats_open(struct inode *inode, struct file *file)
1023 {
1024 	struct dasd_profile *profile = inode->i_private;
1025 	return single_open(file, dasd_stats_show, profile);
1026 }
1027 
1028 static const struct file_operations dasd_stats_raw_fops = {
1029 	.owner		= THIS_MODULE,
1030 	.open		= dasd_stats_open,
1031 	.read		= seq_read,
1032 	.llseek		= seq_lseek,
1033 	.release	= single_release,
1034 	.write		= dasd_stats_write,
1035 };
1036 
dasd_profile_init(struct dasd_profile * profile,struct dentry * base_dentry)1037 static void dasd_profile_init(struct dasd_profile *profile,
1038 			      struct dentry *base_dentry)
1039 {
1040 	umode_t mode;
1041 	struct dentry *pde;
1042 
1043 	if (!base_dentry)
1044 		return;
1045 	profile->dentry = NULL;
1046 	profile->data = NULL;
1047 	mode = (S_IRUSR | S_IWUSR | S_IFREG);
1048 	pde = debugfs_create_file("statistics", mode, base_dentry,
1049 				  profile, &dasd_stats_raw_fops);
1050 	if (pde && !IS_ERR(pde))
1051 		profile->dentry = pde;
1052 	return;
1053 }
1054 
dasd_profile_exit(struct dasd_profile * profile)1055 static void dasd_profile_exit(struct dasd_profile *profile)
1056 {
1057 	dasd_profile_off(profile);
1058 	debugfs_remove(profile->dentry);
1059 	profile->dentry = NULL;
1060 }
1061 
dasd_statistics_removeroot(void)1062 static void dasd_statistics_removeroot(void)
1063 {
1064 	dasd_global_profile_level = DASD_PROFILE_OFF;
1065 	dasd_profile_exit(&dasd_global_profile);
1066 	debugfs_remove(dasd_debugfs_global_entry);
1067 	debugfs_remove(dasd_debugfs_root_entry);
1068 }
1069 
dasd_statistics_createroot(void)1070 static void dasd_statistics_createroot(void)
1071 {
1072 	struct dentry *pde;
1073 
1074 	dasd_debugfs_root_entry = NULL;
1075 	pde = debugfs_create_dir("dasd", NULL);
1076 	if (!pde || IS_ERR(pde))
1077 		goto error;
1078 	dasd_debugfs_root_entry = pde;
1079 	pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1080 	if (!pde || IS_ERR(pde))
1081 		goto error;
1082 	dasd_debugfs_global_entry = pde;
1083 	dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1084 	return;
1085 
1086 error:
1087 	DBF_EVENT(DBF_ERR, "%s",
1088 		  "Creation of the dasd debugfs interface failed");
1089 	dasd_statistics_removeroot();
1090 	return;
1091 }
1092 
1093 #else
1094 #define dasd_profile_start(block, cqr, req) do {} while (0)
1095 #define dasd_profile_end(block, cqr, req) do {} while (0)
1096 
dasd_statistics_createroot(void)1097 static void dasd_statistics_createroot(void)
1098 {
1099 	return;
1100 }
1101 
dasd_statistics_removeroot(void)1102 static void dasd_statistics_removeroot(void)
1103 {
1104 	return;
1105 }
1106 
dasd_stats_generic_show(struct seq_file * m,void * v)1107 int dasd_stats_generic_show(struct seq_file *m, void *v)
1108 {
1109 	seq_puts(m, "Statistics are not activated in this kernel\n");
1110 	return 0;
1111 }
1112 
dasd_profile_init(struct dasd_profile * profile,struct dentry * base_dentry)1113 static void dasd_profile_init(struct dasd_profile *profile,
1114 			      struct dentry *base_dentry)
1115 {
1116 	return;
1117 }
1118 
dasd_profile_exit(struct dasd_profile * profile)1119 static void dasd_profile_exit(struct dasd_profile *profile)
1120 {
1121 	return;
1122 }
1123 
dasd_profile_on(struct dasd_profile * profile)1124 int dasd_profile_on(struct dasd_profile *profile)
1125 {
1126 	return 0;
1127 }
1128 
1129 #endif				/* CONFIG_DASD_PROFILE */
1130 
dasd_hosts_show(struct seq_file * m,void * v)1131 static int dasd_hosts_show(struct seq_file *m, void *v)
1132 {
1133 	struct dasd_device *device;
1134 	int rc = -EOPNOTSUPP;
1135 
1136 	device = m->private;
1137 	dasd_get_device(device);
1138 
1139 	if (device->discipline->hosts_print)
1140 		rc = device->discipline->hosts_print(device, m);
1141 
1142 	dasd_put_device(device);
1143 	return rc;
1144 }
1145 
1146 DEFINE_SHOW_ATTRIBUTE(dasd_hosts);
1147 
dasd_hosts_exit(struct dasd_device * device)1148 static void dasd_hosts_exit(struct dasd_device *device)
1149 {
1150 	debugfs_remove(device->hosts_dentry);
1151 	device->hosts_dentry = NULL;
1152 }
1153 
dasd_hosts_init(struct dentry * base_dentry,struct dasd_device * device)1154 static void dasd_hosts_init(struct dentry *base_dentry,
1155 			    struct dasd_device *device)
1156 {
1157 	struct dentry *pde;
1158 	umode_t mode;
1159 
1160 	if (!base_dentry)
1161 		return;
1162 
1163 	mode = S_IRUSR | S_IFREG;
1164 	pde = debugfs_create_file("host_access_list", mode, base_dentry,
1165 				  device, &dasd_hosts_fops);
1166 	if (pde && !IS_ERR(pde))
1167 		device->hosts_dentry = pde;
1168 }
1169 
dasd_smalloc_request(int magic,int cplength,int datasize,struct dasd_device * device,struct dasd_ccw_req * cqr)1170 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength, int datasize,
1171 					  struct dasd_device *device,
1172 					  struct dasd_ccw_req *cqr)
1173 {
1174 	unsigned long flags;
1175 	char *data, *chunk;
1176 	int size = 0;
1177 
1178 	if (cplength > 0)
1179 		size += cplength * sizeof(struct ccw1);
1180 	if (datasize > 0)
1181 		size += datasize;
1182 	if (!cqr)
1183 		size += (sizeof(*cqr) + 7L) & -8L;
1184 
1185 	spin_lock_irqsave(&device->mem_lock, flags);
1186 	data = chunk = dasd_alloc_chunk(&device->ccw_chunks, size);
1187 	spin_unlock_irqrestore(&device->mem_lock, flags);
1188 	if (!chunk)
1189 		return ERR_PTR(-ENOMEM);
1190 	if (!cqr) {
1191 		cqr = (void *) data;
1192 		data += (sizeof(*cqr) + 7L) & -8L;
1193 	}
1194 	memset(cqr, 0, sizeof(*cqr));
1195 	cqr->mem_chunk = chunk;
1196 	if (cplength > 0) {
1197 		cqr->cpaddr = data;
1198 		data += cplength * sizeof(struct ccw1);
1199 		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1200 	}
1201 	if (datasize > 0) {
1202 		cqr->data = data;
1203  		memset(cqr->data, 0, datasize);
1204 	}
1205 	cqr->magic = magic;
1206 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1207 	dasd_get_device(device);
1208 	return cqr;
1209 }
1210 EXPORT_SYMBOL(dasd_smalloc_request);
1211 
dasd_fmalloc_request(int magic,int cplength,int datasize,struct dasd_device * device)1212 struct dasd_ccw_req *dasd_fmalloc_request(int magic, int cplength,
1213 					  int datasize,
1214 					  struct dasd_device *device)
1215 {
1216 	struct dasd_ccw_req *cqr;
1217 	unsigned long flags;
1218 	int size, cqr_size;
1219 	char *data;
1220 
1221 	cqr_size = (sizeof(*cqr) + 7L) & -8L;
1222 	size = cqr_size;
1223 	if (cplength > 0)
1224 		size += cplength * sizeof(struct ccw1);
1225 	if (datasize > 0)
1226 		size += datasize;
1227 
1228 	spin_lock_irqsave(&device->mem_lock, flags);
1229 	cqr = dasd_alloc_chunk(&device->ese_chunks, size);
1230 	spin_unlock_irqrestore(&device->mem_lock, flags);
1231 	if (!cqr)
1232 		return ERR_PTR(-ENOMEM);
1233 	memset(cqr, 0, sizeof(*cqr));
1234 	data = (char *)cqr + cqr_size;
1235 	cqr->cpaddr = NULL;
1236 	if (cplength > 0) {
1237 		cqr->cpaddr = data;
1238 		data += cplength * sizeof(struct ccw1);
1239 		memset(cqr->cpaddr, 0, cplength * sizeof(struct ccw1));
1240 	}
1241 	cqr->data = NULL;
1242 	if (datasize > 0) {
1243 		cqr->data = data;
1244 		memset(cqr->data, 0, datasize);
1245 	}
1246 
1247 	cqr->magic = magic;
1248 	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1249 	dasd_get_device(device);
1250 
1251 	return cqr;
1252 }
1253 EXPORT_SYMBOL(dasd_fmalloc_request);
1254 
dasd_sfree_request(struct dasd_ccw_req * cqr,struct dasd_device * device)1255 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1256 {
1257 	unsigned long flags;
1258 
1259 	spin_lock_irqsave(&device->mem_lock, flags);
1260 	dasd_free_chunk(&device->ccw_chunks, cqr->mem_chunk);
1261 	spin_unlock_irqrestore(&device->mem_lock, flags);
1262 	dasd_put_device(device);
1263 }
1264 EXPORT_SYMBOL(dasd_sfree_request);
1265 
dasd_ffree_request(struct dasd_ccw_req * cqr,struct dasd_device * device)1266 void dasd_ffree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1267 {
1268 	unsigned long flags;
1269 
1270 	spin_lock_irqsave(&device->mem_lock, flags);
1271 	dasd_free_chunk(&device->ese_chunks, cqr);
1272 	spin_unlock_irqrestore(&device->mem_lock, flags);
1273 	dasd_put_device(device);
1274 }
1275 EXPORT_SYMBOL(dasd_ffree_request);
1276 
1277 /*
1278  * Check discipline magic in cqr.
1279  */
dasd_check_cqr(struct dasd_ccw_req * cqr)1280 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1281 {
1282 	struct dasd_device *device;
1283 
1284 	if (cqr == NULL)
1285 		return -EINVAL;
1286 	device = cqr->startdev;
1287 	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1288 		DBF_DEV_EVENT(DBF_WARNING, device,
1289 			    " dasd_ccw_req 0x%08x magic doesn't match"
1290 			    " discipline 0x%08x",
1291 			    cqr->magic,
1292 			    *(unsigned int *) device->discipline->name);
1293 		return -EINVAL;
1294 	}
1295 	return 0;
1296 }
1297 
1298 /*
1299  * Terminate the current i/o and set the request to clear_pending.
1300  * Timer keeps device runnig.
1301  * ccw_device_clear can fail if the i/o subsystem
1302  * is in a bad mood.
1303  */
dasd_term_IO(struct dasd_ccw_req * cqr)1304 int dasd_term_IO(struct dasd_ccw_req *cqr)
1305 {
1306 	struct dasd_device *device;
1307 	int retries, rc;
1308 	char errorstring[ERRORLENGTH];
1309 
1310 	/* Check the cqr */
1311 	rc = dasd_check_cqr(cqr);
1312 	if (rc)
1313 		return rc;
1314 	retries = 0;
1315 	device = (struct dasd_device *) cqr->startdev;
1316 	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1317 		rc = ccw_device_clear(device->cdev, (long) cqr);
1318 		switch (rc) {
1319 		case 0:	/* termination successful */
1320 			cqr->status = DASD_CQR_CLEAR_PENDING;
1321 			cqr->stopclk = get_tod_clock();
1322 			cqr->starttime = 0;
1323 			DBF_DEV_EVENT(DBF_DEBUG, device,
1324 				      "terminate cqr %p successful",
1325 				      cqr);
1326 			break;
1327 		case -ENODEV:
1328 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1329 				      "device gone, retry");
1330 			break;
1331 		case -EINVAL:
1332 			/*
1333 			 * device not valid so no I/O could be running
1334 			 * handle CQR as termination successful
1335 			 */
1336 			cqr->status = DASD_CQR_CLEARED;
1337 			cqr->stopclk = get_tod_clock();
1338 			cqr->starttime = 0;
1339 			/* no retries for invalid devices */
1340 			cqr->retries = -1;
1341 			DBF_DEV_EVENT(DBF_ERR, device, "%s",
1342 				      "EINVAL, handle as terminated");
1343 			/* fake rc to success */
1344 			rc = 0;
1345 			break;
1346 		default:
1347 			/* internal error 10 - unknown rc*/
1348 			snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1349 			dev_err(&device->cdev->dev, "An error occurred in the "
1350 				"DASD device driver, reason=%s\n", errorstring);
1351 			BUG();
1352 			break;
1353 		}
1354 		retries++;
1355 	}
1356 	dasd_schedule_device_bh(device);
1357 	return rc;
1358 }
1359 EXPORT_SYMBOL(dasd_term_IO);
1360 
1361 /*
1362  * Start the i/o. This start_IO can fail if the channel is really busy.
1363  * In that case set up a timer to start the request later.
1364  */
dasd_start_IO(struct dasd_ccw_req * cqr)1365 int dasd_start_IO(struct dasd_ccw_req *cqr)
1366 {
1367 	struct dasd_device *device;
1368 	int rc;
1369 	char errorstring[ERRORLENGTH];
1370 
1371 	/* Check the cqr */
1372 	rc = dasd_check_cqr(cqr);
1373 	if (rc) {
1374 		cqr->intrc = rc;
1375 		return rc;
1376 	}
1377 	device = (struct dasd_device *) cqr->startdev;
1378 	if (((cqr->block &&
1379 	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1380 	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1381 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1382 		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1383 			      "because of stolen lock", cqr);
1384 		cqr->status = DASD_CQR_ERROR;
1385 		cqr->intrc = -EPERM;
1386 		return -EPERM;
1387 	}
1388 	if (cqr->retries < 0) {
1389 		/* internal error 14 - start_IO run out of retries */
1390 		sprintf(errorstring, "14 %p", cqr);
1391 		dev_err(&device->cdev->dev, "An error occurred in the DASD "
1392 			"device driver, reason=%s\n", errorstring);
1393 		cqr->status = DASD_CQR_ERROR;
1394 		return -EIO;
1395 	}
1396 	cqr->startclk = get_tod_clock();
1397 	cqr->starttime = jiffies;
1398 	cqr->retries--;
1399 	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1400 		cqr->lpm &= dasd_path_get_opm(device);
1401 		if (!cqr->lpm)
1402 			cqr->lpm = dasd_path_get_opm(device);
1403 	}
1404 	/*
1405 	 * remember the amount of formatted tracks to prevent double format on
1406 	 * ESE devices
1407 	 */
1408 	if (cqr->block)
1409 		cqr->trkcount = atomic_read(&cqr->block->trkcount);
1410 
1411 	if (cqr->cpmode == 1) {
1412 		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1413 					 (long) cqr, cqr->lpm);
1414 	} else {
1415 		rc = ccw_device_start(device->cdev, cqr->cpaddr,
1416 				      (long) cqr, cqr->lpm, 0);
1417 	}
1418 	switch (rc) {
1419 	case 0:
1420 		cqr->status = DASD_CQR_IN_IO;
1421 		break;
1422 	case -EBUSY:
1423 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1424 			      "start_IO: device busy, retry later");
1425 		break;
1426 	case -EACCES:
1427 		/* -EACCES indicates that the request used only a subset of the
1428 		 * available paths and all these paths are gone. If the lpm of
1429 		 * this request was only a subset of the opm (e.g. the ppm) then
1430 		 * we just do a retry with all available paths.
1431 		 * If we already use the full opm, something is amiss, and we
1432 		 * need a full path verification.
1433 		 */
1434 		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1435 			DBF_DEV_EVENT(DBF_WARNING, device,
1436 				      "start_IO: selected paths gone (%x)",
1437 				      cqr->lpm);
1438 		} else if (cqr->lpm != dasd_path_get_opm(device)) {
1439 			cqr->lpm = dasd_path_get_opm(device);
1440 			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1441 				      "start_IO: selected paths gone,"
1442 				      " retry on all paths");
1443 		} else {
1444 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1445 				      "start_IO: all paths in opm gone,"
1446 				      " do path verification");
1447 			dasd_generic_last_path_gone(device);
1448 			dasd_path_no_path(device);
1449 			dasd_path_set_tbvpm(device,
1450 					  ccw_device_get_path_mask(
1451 						  device->cdev));
1452 		}
1453 		break;
1454 	case -ENODEV:
1455 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1456 			      "start_IO: -ENODEV device gone, retry");
1457 		/* this is equivalent to CC=3 for SSCH report this to EER */
1458 		dasd_handle_autoquiesce(device, cqr, DASD_EER_STARTIO);
1459 		break;
1460 	case -EIO:
1461 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1462 			      "start_IO: -EIO device gone, retry");
1463 		break;
1464 	case -EINVAL:
1465 		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1466 			      "start_IO: -EINVAL device currently "
1467 			      "not accessible");
1468 		break;
1469 	default:
1470 		/* internal error 11 - unknown rc */
1471 		snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1472 		dev_err(&device->cdev->dev,
1473 			"An error occurred in the DASD device driver, "
1474 			"reason=%s\n", errorstring);
1475 		BUG();
1476 		break;
1477 	}
1478 	cqr->intrc = rc;
1479 	return rc;
1480 }
1481 EXPORT_SYMBOL(dasd_start_IO);
1482 
1483 /*
1484  * Timeout function for dasd devices. This is used for different purposes
1485  *  1) missing interrupt handler for normal operation
1486  *  2) delayed start of request where start_IO failed with -EBUSY
1487  *  3) timeout for missing state change interrupts
1488  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1489  * DASD_CQR_QUEUED for 2) and 3).
1490  */
dasd_device_timeout(struct timer_list * t)1491 static void dasd_device_timeout(struct timer_list *t)
1492 {
1493 	unsigned long flags;
1494 	struct dasd_device *device;
1495 
1496 	device = from_timer(device, t, timer);
1497 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1498 	/* re-activate request queue */
1499 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1500 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1501 	dasd_schedule_device_bh(device);
1502 }
1503 
1504 /*
1505  * Setup timeout for a device in jiffies.
1506  */
dasd_device_set_timer(struct dasd_device * device,int expires)1507 void dasd_device_set_timer(struct dasd_device *device, int expires)
1508 {
1509 	if (expires == 0)
1510 		del_timer(&device->timer);
1511 	else
1512 		mod_timer(&device->timer, jiffies + expires);
1513 }
1514 EXPORT_SYMBOL(dasd_device_set_timer);
1515 
1516 /*
1517  * Clear timeout for a device.
1518  */
dasd_device_clear_timer(struct dasd_device * device)1519 void dasd_device_clear_timer(struct dasd_device *device)
1520 {
1521 	del_timer(&device->timer);
1522 }
1523 EXPORT_SYMBOL(dasd_device_clear_timer);
1524 
dasd_handle_killed_request(struct ccw_device * cdev,unsigned long intparm)1525 static void dasd_handle_killed_request(struct ccw_device *cdev,
1526 				       unsigned long intparm)
1527 {
1528 	struct dasd_ccw_req *cqr;
1529 	struct dasd_device *device;
1530 
1531 	if (!intparm)
1532 		return;
1533 	cqr = (struct dasd_ccw_req *) intparm;
1534 	if (cqr->status != DASD_CQR_IN_IO) {
1535 		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1536 				"invalid status in handle_killed_request: "
1537 				"%02x", cqr->status);
1538 		return;
1539 	}
1540 
1541 	device = dasd_device_from_cdev_locked(cdev);
1542 	if (IS_ERR(device)) {
1543 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1544 				"unable to get device from cdev");
1545 		return;
1546 	}
1547 
1548 	if (!cqr->startdev ||
1549 	    device != cqr->startdev ||
1550 	    strncmp(cqr->startdev->discipline->ebcname,
1551 		    (char *) &cqr->magic, 4)) {
1552 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1553 				"invalid device in request");
1554 		dasd_put_device(device);
1555 		return;
1556 	}
1557 
1558 	/* Schedule request to be retried. */
1559 	cqr->status = DASD_CQR_QUEUED;
1560 
1561 	dasd_device_clear_timer(device);
1562 	dasd_schedule_device_bh(device);
1563 	dasd_put_device(device);
1564 }
1565 
dasd_generic_handle_state_change(struct dasd_device * device)1566 void dasd_generic_handle_state_change(struct dasd_device *device)
1567 {
1568 	/* First of all start sense subsystem status request. */
1569 	dasd_eer_snss(device);
1570 
1571 	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1572 	dasd_schedule_device_bh(device);
1573 	if (device->block) {
1574 		dasd_schedule_block_bh(device->block);
1575 		if (device->block->gdp)
1576 			blk_mq_run_hw_queues(device->block->gdp->queue, true);
1577 	}
1578 }
1579 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1580 
dasd_check_hpf_error(struct irb * irb)1581 static int dasd_check_hpf_error(struct irb *irb)
1582 {
1583 	return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1584 	    (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1585 	     irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1586 }
1587 
dasd_ese_needs_format(struct dasd_block * block,struct irb * irb)1588 static int dasd_ese_needs_format(struct dasd_block *block, struct irb *irb)
1589 {
1590 	struct dasd_device *device = NULL;
1591 	u8 *sense = NULL;
1592 
1593 	if (!block)
1594 		return 0;
1595 	device = block->base;
1596 	if (!device || !device->discipline->is_ese)
1597 		return 0;
1598 	if (!device->discipline->is_ese(device))
1599 		return 0;
1600 
1601 	sense = dasd_get_sense(irb);
1602 	if (!sense)
1603 		return 0;
1604 
1605 	return !!(sense[1] & SNS1_NO_REC_FOUND) ||
1606 		!!(sense[1] & SNS1_FILE_PROTECTED) ||
1607 		scsw_cstat(&irb->scsw) == SCHN_STAT_INCORR_LEN;
1608 }
1609 
dasd_ese_oos_cond(u8 * sense)1610 static int dasd_ese_oos_cond(u8 *sense)
1611 {
1612 	return sense[0] & SNS0_EQUIPMENT_CHECK &&
1613 		sense[1] & SNS1_PERM_ERR &&
1614 		sense[1] & SNS1_WRITE_INHIBITED &&
1615 		sense[25] == 0x01;
1616 }
1617 
1618 /*
1619  * Interrupt handler for "normal" ssch-io based dasd devices.
1620  */
dasd_int_handler(struct ccw_device * cdev,unsigned long intparm,struct irb * irb)1621 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1622 		      struct irb *irb)
1623 {
1624 	struct dasd_ccw_req *cqr, *next, *fcqr;
1625 	struct dasd_device *device;
1626 	unsigned long now;
1627 	int nrf_suppressed = 0;
1628 	int fp_suppressed = 0;
1629 	struct request *req;
1630 	u8 *sense = NULL;
1631 	int expires;
1632 
1633 	cqr = (struct dasd_ccw_req *) intparm;
1634 	if (IS_ERR(irb)) {
1635 		switch (PTR_ERR(irb)) {
1636 		case -EIO:
1637 			if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1638 				device = cqr->startdev;
1639 				cqr->status = DASD_CQR_CLEARED;
1640 				dasd_device_clear_timer(device);
1641 				wake_up(&dasd_flush_wq);
1642 				dasd_schedule_device_bh(device);
1643 				return;
1644 			}
1645 			break;
1646 		case -ETIMEDOUT:
1647 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1648 					"request timed out\n", __func__);
1649 			break;
1650 		default:
1651 			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1652 					"unknown error %ld\n", __func__,
1653 					PTR_ERR(irb));
1654 		}
1655 		dasd_handle_killed_request(cdev, intparm);
1656 		return;
1657 	}
1658 
1659 	now = get_tod_clock();
1660 	/* check for conditions that should be handled immediately */
1661 	if (!cqr ||
1662 	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1663 	      scsw_cstat(&irb->scsw) == 0)) {
1664 		if (cqr)
1665 			memcpy(&cqr->irb, irb, sizeof(*irb));
1666 		device = dasd_device_from_cdev_locked(cdev);
1667 		if (IS_ERR(device))
1668 			return;
1669 		/* ignore unsolicited interrupts for DIAG discipline */
1670 		if (device->discipline == dasd_diag_discipline_pointer) {
1671 			dasd_put_device(device);
1672 			return;
1673 		}
1674 
1675 		/*
1676 		 * In some cases 'File Protected' or 'No Record Found' errors
1677 		 * might be expected and debug log messages for the
1678 		 * corresponding interrupts shouldn't be written then.
1679 		 * Check if either of the according suppress bits is set.
1680 		 */
1681 		sense = dasd_get_sense(irb);
1682 		if (sense) {
1683 			fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1684 				test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1685 			nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1686 				test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1687 
1688 			/*
1689 			 * Extent pool probably out-of-space.
1690 			 * Stop device and check exhaust level.
1691 			 */
1692 			if (dasd_ese_oos_cond(sense)) {
1693 				dasd_generic_space_exhaust(device, cqr);
1694 				device->discipline->ext_pool_exhaust(device, cqr);
1695 				dasd_put_device(device);
1696 				return;
1697 			}
1698 		}
1699 		if (!(fp_suppressed || nrf_suppressed))
1700 			device->discipline->dump_sense_dbf(device, irb, "int");
1701 
1702 		if (device->features & DASD_FEATURE_ERPLOG)
1703 			device->discipline->dump_sense(device, cqr, irb);
1704 		device->discipline->check_for_device_change(device, cqr, irb);
1705 		dasd_put_device(device);
1706 	}
1707 
1708 	/* check for attention message */
1709 	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1710 		device = dasd_device_from_cdev_locked(cdev);
1711 		if (!IS_ERR(device)) {
1712 			device->discipline->check_attention(device,
1713 							    irb->esw.esw1.lpum);
1714 			dasd_put_device(device);
1715 		}
1716 	}
1717 
1718 	if (!cqr)
1719 		return;
1720 
1721 	device = (struct dasd_device *) cqr->startdev;
1722 	if (!device ||
1723 	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1724 		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1725 				"invalid device in request");
1726 		return;
1727 	}
1728 
1729 	if (dasd_ese_needs_format(cqr->block, irb)) {
1730 		req = dasd_get_callback_data(cqr);
1731 		if (!req) {
1732 			cqr->status = DASD_CQR_ERROR;
1733 			return;
1734 		}
1735 		if (rq_data_dir(req) == READ) {
1736 			device->discipline->ese_read(cqr, irb);
1737 			cqr->status = DASD_CQR_SUCCESS;
1738 			cqr->stopclk = now;
1739 			dasd_device_clear_timer(device);
1740 			dasd_schedule_device_bh(device);
1741 			return;
1742 		}
1743 		fcqr = device->discipline->ese_format(device, cqr, irb);
1744 		if (IS_ERR(fcqr)) {
1745 			if (PTR_ERR(fcqr) == -EINVAL) {
1746 				cqr->status = DASD_CQR_ERROR;
1747 				return;
1748 			}
1749 			/*
1750 			 * If we can't format now, let the request go
1751 			 * one extra round. Maybe we can format later.
1752 			 */
1753 			cqr->status = DASD_CQR_QUEUED;
1754 			dasd_schedule_device_bh(device);
1755 			return;
1756 		} else {
1757 			fcqr->status = DASD_CQR_QUEUED;
1758 			cqr->status = DASD_CQR_QUEUED;
1759 			list_add(&fcqr->devlist, &device->ccw_queue);
1760 			dasd_schedule_device_bh(device);
1761 			return;
1762 		}
1763 	}
1764 
1765 	/* Check for clear pending */
1766 	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1767 	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1768 		cqr->status = DASD_CQR_CLEARED;
1769 		dasd_device_clear_timer(device);
1770 		wake_up(&dasd_flush_wq);
1771 		dasd_schedule_device_bh(device);
1772 		return;
1773 	}
1774 
1775 	/* check status - the request might have been killed by dyn detach */
1776 	if (cqr->status != DASD_CQR_IN_IO) {
1777 		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1778 			      "status %02x", dev_name(&cdev->dev), cqr->status);
1779 		return;
1780 	}
1781 
1782 	next = NULL;
1783 	expires = 0;
1784 	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1785 	    scsw_cstat(&irb->scsw) == 0) {
1786 		/* request was completed successfully */
1787 		cqr->status = DASD_CQR_SUCCESS;
1788 		cqr->stopclk = now;
1789 		/* Start first request on queue if possible -> fast_io. */
1790 		if (cqr->devlist.next != &device->ccw_queue) {
1791 			next = list_entry(cqr->devlist.next,
1792 					  struct dasd_ccw_req, devlist);
1793 		}
1794 	} else {  /* error */
1795 		/* check for HPF error
1796 		 * call discipline function to requeue all requests
1797 		 * and disable HPF accordingly
1798 		 */
1799 		if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1800 		    device->discipline->handle_hpf_error)
1801 			device->discipline->handle_hpf_error(device, irb);
1802 		/*
1803 		 * If we don't want complex ERP for this request, then just
1804 		 * reset this and retry it in the fastpath
1805 		 */
1806 		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1807 		    cqr->retries > 0) {
1808 			if (cqr->lpm == dasd_path_get_opm(device))
1809 				DBF_DEV_EVENT(DBF_DEBUG, device,
1810 					      "default ERP in fastpath "
1811 					      "(%i retries left)",
1812 					      cqr->retries);
1813 			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1814 				cqr->lpm = dasd_path_get_opm(device);
1815 			cqr->status = DASD_CQR_QUEUED;
1816 			next = cqr;
1817 		} else
1818 			cqr->status = DASD_CQR_ERROR;
1819 	}
1820 	if (next && (next->status == DASD_CQR_QUEUED) &&
1821 	    (!device->stopped)) {
1822 		if (device->discipline->start_IO(next) == 0)
1823 			expires = next->expires;
1824 	}
1825 	if (expires != 0)
1826 		dasd_device_set_timer(device, expires);
1827 	else
1828 		dasd_device_clear_timer(device);
1829 	dasd_schedule_device_bh(device);
1830 }
1831 EXPORT_SYMBOL(dasd_int_handler);
1832 
dasd_generic_uc_handler(struct ccw_device * cdev,struct irb * irb)1833 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1834 {
1835 	struct dasd_device *device;
1836 
1837 	device = dasd_device_from_cdev_locked(cdev);
1838 
1839 	if (IS_ERR(device))
1840 		goto out;
1841 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1842 	   device->state != device->target ||
1843 	   !device->discipline->check_for_device_change){
1844 		dasd_put_device(device);
1845 		goto out;
1846 	}
1847 	if (device->discipline->dump_sense_dbf)
1848 		device->discipline->dump_sense_dbf(device, irb, "uc");
1849 	device->discipline->check_for_device_change(device, NULL, irb);
1850 	dasd_put_device(device);
1851 out:
1852 	return UC_TODO_RETRY;
1853 }
1854 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1855 
1856 /*
1857  * If we have an error on a dasd_block layer request then we cancel
1858  * and return all further requests from the same dasd_block as well.
1859  */
__dasd_device_recovery(struct dasd_device * device,struct dasd_ccw_req * ref_cqr)1860 static void __dasd_device_recovery(struct dasd_device *device,
1861 				   struct dasd_ccw_req *ref_cqr)
1862 {
1863 	struct list_head *l, *n;
1864 	struct dasd_ccw_req *cqr;
1865 
1866 	/*
1867 	 * only requeue request that came from the dasd_block layer
1868 	 */
1869 	if (!ref_cqr->block)
1870 		return;
1871 
1872 	list_for_each_safe(l, n, &device->ccw_queue) {
1873 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1874 		if (cqr->status == DASD_CQR_QUEUED &&
1875 		    ref_cqr->block == cqr->block) {
1876 			cqr->status = DASD_CQR_CLEARED;
1877 		}
1878 	}
1879 };
1880 
1881 /*
1882  * Remove those ccw requests from the queue that need to be returned
1883  * to the upper layer.
1884  */
__dasd_device_process_ccw_queue(struct dasd_device * device,struct list_head * final_queue)1885 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1886 					    struct list_head *final_queue)
1887 {
1888 	struct list_head *l, *n;
1889 	struct dasd_ccw_req *cqr;
1890 
1891 	/* Process request with final status. */
1892 	list_for_each_safe(l, n, &device->ccw_queue) {
1893 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1894 
1895 		/* Skip any non-final request. */
1896 		if (cqr->status == DASD_CQR_QUEUED ||
1897 		    cqr->status == DASD_CQR_IN_IO ||
1898 		    cqr->status == DASD_CQR_CLEAR_PENDING)
1899 			continue;
1900 		if (cqr->status == DASD_CQR_ERROR) {
1901 			__dasd_device_recovery(device, cqr);
1902 		}
1903 		/* Rechain finished requests to final queue */
1904 		list_move_tail(&cqr->devlist, final_queue);
1905 	}
1906 }
1907 
__dasd_process_cqr(struct dasd_device * device,struct dasd_ccw_req * cqr)1908 static void __dasd_process_cqr(struct dasd_device *device,
1909 			       struct dasd_ccw_req *cqr)
1910 {
1911 	char errorstring[ERRORLENGTH];
1912 
1913 	switch (cqr->status) {
1914 	case DASD_CQR_SUCCESS:
1915 		cqr->status = DASD_CQR_DONE;
1916 		break;
1917 	case DASD_CQR_ERROR:
1918 		cqr->status = DASD_CQR_NEED_ERP;
1919 		break;
1920 	case DASD_CQR_CLEARED:
1921 		cqr->status = DASD_CQR_TERMINATED;
1922 		break;
1923 	default:
1924 		/* internal error 12 - wrong cqr status*/
1925 		snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1926 		dev_err(&device->cdev->dev,
1927 			"An error occurred in the DASD device driver, "
1928 			"reason=%s\n", errorstring);
1929 		BUG();
1930 	}
1931 	if (cqr->callback)
1932 		cqr->callback(cqr, cqr->callback_data);
1933 }
1934 
1935 /*
1936  * the cqrs from the final queue are returned to the upper layer
1937  * by setting a dasd_block state and calling the callback function
1938  */
__dasd_device_process_final_queue(struct dasd_device * device,struct list_head * final_queue)1939 static void __dasd_device_process_final_queue(struct dasd_device *device,
1940 					      struct list_head *final_queue)
1941 {
1942 	struct list_head *l, *n;
1943 	struct dasd_ccw_req *cqr;
1944 	struct dasd_block *block;
1945 
1946 	list_for_each_safe(l, n, final_queue) {
1947 		cqr = list_entry(l, struct dasd_ccw_req, devlist);
1948 		list_del_init(&cqr->devlist);
1949 		block = cqr->block;
1950 		if (!block) {
1951 			__dasd_process_cqr(device, cqr);
1952 		} else {
1953 			spin_lock_bh(&block->queue_lock);
1954 			__dasd_process_cqr(device, cqr);
1955 			spin_unlock_bh(&block->queue_lock);
1956 		}
1957 	}
1958 }
1959 
1960 /*
1961  * check if device should be autoquiesced due to too many timeouts
1962  */
__dasd_device_check_autoquiesce_timeout(struct dasd_device * device,struct dasd_ccw_req * cqr)1963 static void __dasd_device_check_autoquiesce_timeout(struct dasd_device *device,
1964 						    struct dasd_ccw_req *cqr)
1965 {
1966 	if ((device->default_retries - cqr->retries) >= device->aq_timeouts)
1967 		dasd_handle_autoquiesce(device, cqr, DASD_EER_TIMEOUTS);
1968 }
1969 
1970 /*
1971  * Take a look at the first request on the ccw queue and check
1972  * if it reached its expire time. If so, terminate the IO.
1973  */
__dasd_device_check_expire(struct dasd_device * device)1974 static void __dasd_device_check_expire(struct dasd_device *device)
1975 {
1976 	struct dasd_ccw_req *cqr;
1977 
1978 	if (list_empty(&device->ccw_queue))
1979 		return;
1980 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1981 	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1982 	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1983 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1984 			/*
1985 			 * IO in safe offline processing should not
1986 			 * run out of retries
1987 			 */
1988 			cqr->retries++;
1989 		}
1990 		if (device->discipline->term_IO(cqr) != 0) {
1991 			/* Hmpf, try again in 5 sec */
1992 			dev_err(&device->cdev->dev,
1993 				"cqr %p timed out (%lus) but cannot be "
1994 				"ended, retrying in 5 s\n",
1995 				cqr, (cqr->expires/HZ));
1996 			cqr->expires += 5*HZ;
1997 			dasd_device_set_timer(device, 5*HZ);
1998 		} else {
1999 			dev_err(&device->cdev->dev,
2000 				"cqr %p timed out (%lus), %i retries "
2001 				"remaining\n", cqr, (cqr->expires/HZ),
2002 				cqr->retries);
2003 		}
2004 		__dasd_device_check_autoquiesce_timeout(device, cqr);
2005 	}
2006 }
2007 
2008 /*
2009  * return 1 when device is not eligible for IO
2010  */
__dasd_device_is_unusable(struct dasd_device * device,struct dasd_ccw_req * cqr)2011 static int __dasd_device_is_unusable(struct dasd_device *device,
2012 				     struct dasd_ccw_req *cqr)
2013 {
2014 	int mask = ~(DASD_STOPPED_DC_WAIT | DASD_STOPPED_NOSPC);
2015 
2016 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
2017 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
2018 		/*
2019 		 * dasd is being set offline
2020 		 * but it is no safe offline where we have to allow I/O
2021 		 */
2022 		return 1;
2023 	}
2024 	if (device->stopped) {
2025 		if (device->stopped & mask) {
2026 			/* stopped and CQR will not change that. */
2027 			return 1;
2028 		}
2029 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2030 			/* CQR is not able to change device to
2031 			 * operational. */
2032 			return 1;
2033 		}
2034 		/* CQR required to get device operational. */
2035 	}
2036 	return 0;
2037 }
2038 
2039 /*
2040  * Take a look at the first request on the ccw queue and check
2041  * if it needs to be started.
2042  */
__dasd_device_start_head(struct dasd_device * device)2043 static void __dasd_device_start_head(struct dasd_device *device)
2044 {
2045 	struct dasd_ccw_req *cqr;
2046 	int rc;
2047 
2048 	if (list_empty(&device->ccw_queue))
2049 		return;
2050 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2051 	if (cqr->status != DASD_CQR_QUEUED)
2052 		return;
2053 	/* if device is not usable return request to upper layer */
2054 	if (__dasd_device_is_unusable(device, cqr)) {
2055 		cqr->intrc = -EAGAIN;
2056 		cqr->status = DASD_CQR_CLEARED;
2057 		dasd_schedule_device_bh(device);
2058 		return;
2059 	}
2060 
2061 	rc = device->discipline->start_IO(cqr);
2062 	if (rc == 0)
2063 		dasd_device_set_timer(device, cqr->expires);
2064 	else if (rc == -EACCES) {
2065 		dasd_schedule_device_bh(device);
2066 	} else
2067 		/* Hmpf, try again in 1/2 sec */
2068 		dasd_device_set_timer(device, 50);
2069 }
2070 
__dasd_device_check_path_events(struct dasd_device * device)2071 static void __dasd_device_check_path_events(struct dasd_device *device)
2072 {
2073 	__u8 tbvpm, fcsecpm;
2074 	int rc;
2075 
2076 	tbvpm = dasd_path_get_tbvpm(device);
2077 	fcsecpm = dasd_path_get_fcsecpm(device);
2078 
2079 	if (!tbvpm && !fcsecpm)
2080 		return;
2081 
2082 	if (device->stopped & ~(DASD_STOPPED_DC_WAIT))
2083 		return;
2084 
2085 	dasd_path_clear_all_verify(device);
2086 	dasd_path_clear_all_fcsec(device);
2087 
2088 	rc = device->discipline->pe_handler(device, tbvpm, fcsecpm);
2089 	if (rc) {
2090 		dasd_path_add_tbvpm(device, tbvpm);
2091 		dasd_path_add_fcsecpm(device, fcsecpm);
2092 		dasd_device_set_timer(device, 50);
2093 	}
2094 };
2095 
2096 /*
2097  * Go through all request on the dasd_device request queue,
2098  * terminate them on the cdev if necessary, and return them to the
2099  * submitting layer via callback.
2100  * Note:
2101  * Make sure that all 'submitting layers' still exist when
2102  * this function is called!. In other words, when 'device' is a base
2103  * device then all block layer requests must have been removed before
2104  * via dasd_flush_block_queue.
2105  */
dasd_flush_device_queue(struct dasd_device * device)2106 int dasd_flush_device_queue(struct dasd_device *device)
2107 {
2108 	struct dasd_ccw_req *cqr, *n;
2109 	int rc;
2110 	struct list_head flush_queue;
2111 
2112 	INIT_LIST_HEAD(&flush_queue);
2113 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2114 	rc = 0;
2115 	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2116 		/* Check status and move request to flush_queue */
2117 		switch (cqr->status) {
2118 		case DASD_CQR_IN_IO:
2119 			rc = device->discipline->term_IO(cqr);
2120 			if (rc) {
2121 				/* unable to terminate requeust */
2122 				dev_err(&device->cdev->dev,
2123 					"Flushing the DASD request queue "
2124 					"failed for request %p\n", cqr);
2125 				/* stop flush processing */
2126 				goto finished;
2127 			}
2128 			break;
2129 		case DASD_CQR_QUEUED:
2130 			cqr->stopclk = get_tod_clock();
2131 			cqr->status = DASD_CQR_CLEARED;
2132 			break;
2133 		default: /* no need to modify the others */
2134 			break;
2135 		}
2136 		list_move_tail(&cqr->devlist, &flush_queue);
2137 	}
2138 finished:
2139 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2140 	/*
2141 	 * After this point all requests must be in state CLEAR_PENDING,
2142 	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2143 	 * one of the others.
2144 	 */
2145 	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2146 		wait_event(dasd_flush_wq,
2147 			   (cqr->status != DASD_CQR_CLEAR_PENDING));
2148 	/*
2149 	 * Now set each request back to TERMINATED, DONE or NEED_ERP
2150 	 * and call the callback function of flushed requests
2151 	 */
2152 	__dasd_device_process_final_queue(device, &flush_queue);
2153 	return rc;
2154 }
2155 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2156 
2157 /*
2158  * Acquire the device lock and process queues for the device.
2159  */
dasd_device_tasklet(unsigned long data)2160 static void dasd_device_tasklet(unsigned long data)
2161 {
2162 	struct dasd_device *device = (struct dasd_device *) data;
2163 	struct list_head final_queue;
2164 
2165 	atomic_set (&device->tasklet_scheduled, 0);
2166 	INIT_LIST_HEAD(&final_queue);
2167 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2168 	/* Check expire time of first request on the ccw queue. */
2169 	__dasd_device_check_expire(device);
2170 	/* find final requests on ccw queue */
2171 	__dasd_device_process_ccw_queue(device, &final_queue);
2172 	__dasd_device_check_path_events(device);
2173 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2174 	/* Now call the callback function of requests with final status */
2175 	__dasd_device_process_final_queue(device, &final_queue);
2176 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2177 	/* Now check if the head of the ccw queue needs to be started. */
2178 	__dasd_device_start_head(device);
2179 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2180 	if (waitqueue_active(&shutdown_waitq))
2181 		wake_up(&shutdown_waitq);
2182 	dasd_put_device(device);
2183 }
2184 
2185 /*
2186  * Schedules a call to dasd_tasklet over the device tasklet.
2187  */
dasd_schedule_device_bh(struct dasd_device * device)2188 void dasd_schedule_device_bh(struct dasd_device *device)
2189 {
2190 	/* Protect against rescheduling. */
2191 	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2192 		return;
2193 	dasd_get_device(device);
2194 	tasklet_hi_schedule(&device->tasklet);
2195 }
2196 EXPORT_SYMBOL(dasd_schedule_device_bh);
2197 
dasd_device_set_stop_bits(struct dasd_device * device,int bits)2198 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2199 {
2200 	device->stopped |= bits;
2201 }
2202 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2203 
dasd_device_remove_stop_bits(struct dasd_device * device,int bits)2204 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2205 {
2206 	device->stopped &= ~bits;
2207 	if (!device->stopped)
2208 		wake_up(&generic_waitq);
2209 }
2210 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2211 
2212 /*
2213  * Queue a request to the head of the device ccw_queue.
2214  * Start the I/O if possible.
2215  */
dasd_add_request_head(struct dasd_ccw_req * cqr)2216 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2217 {
2218 	struct dasd_device *device;
2219 	unsigned long flags;
2220 
2221 	device = cqr->startdev;
2222 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2223 	cqr->status = DASD_CQR_QUEUED;
2224 	list_add(&cqr->devlist, &device->ccw_queue);
2225 	/* let the bh start the request to keep them in order */
2226 	dasd_schedule_device_bh(device);
2227 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2228 }
2229 EXPORT_SYMBOL(dasd_add_request_head);
2230 
2231 /*
2232  * Queue a request to the tail of the device ccw_queue.
2233  * Start the I/O if possible.
2234  */
dasd_add_request_tail(struct dasd_ccw_req * cqr)2235 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2236 {
2237 	struct dasd_device *device;
2238 	unsigned long flags;
2239 
2240 	device = cqr->startdev;
2241 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2242 	cqr->status = DASD_CQR_QUEUED;
2243 	list_add_tail(&cqr->devlist, &device->ccw_queue);
2244 	/* let the bh start the request to keep them in order */
2245 	dasd_schedule_device_bh(device);
2246 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2247 }
2248 EXPORT_SYMBOL(dasd_add_request_tail);
2249 
2250 /*
2251  * Wakeup helper for the 'sleep_on' functions.
2252  */
dasd_wakeup_cb(struct dasd_ccw_req * cqr,void * data)2253 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2254 {
2255 	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2256 	cqr->callback_data = DASD_SLEEPON_END_TAG;
2257 	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2258 	wake_up(&generic_waitq);
2259 }
2260 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2261 
_wait_for_wakeup(struct dasd_ccw_req * cqr)2262 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2263 {
2264 	struct dasd_device *device;
2265 	int rc;
2266 
2267 	device = cqr->startdev;
2268 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2269 	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2270 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2271 	return rc;
2272 }
2273 
2274 /*
2275  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2276  */
__dasd_sleep_on_erp(struct dasd_ccw_req * cqr)2277 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2278 {
2279 	struct dasd_device *device;
2280 	dasd_erp_fn_t erp_fn;
2281 
2282 	if (cqr->status == DASD_CQR_FILLED)
2283 		return 0;
2284 	device = cqr->startdev;
2285 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2286 		if (cqr->status == DASD_CQR_TERMINATED) {
2287 			device->discipline->handle_terminated_request(cqr);
2288 			return 1;
2289 		}
2290 		if (cqr->status == DASD_CQR_NEED_ERP) {
2291 			erp_fn = device->discipline->erp_action(cqr);
2292 			erp_fn(cqr);
2293 			return 1;
2294 		}
2295 		if (cqr->status == DASD_CQR_FAILED)
2296 			dasd_log_sense(cqr, &cqr->irb);
2297 		if (cqr->refers) {
2298 			__dasd_process_erp(device, cqr);
2299 			return 1;
2300 		}
2301 	}
2302 	return 0;
2303 }
2304 
__dasd_sleep_on_loop_condition(struct dasd_ccw_req * cqr)2305 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2306 {
2307 	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2308 		if (cqr->refers) /* erp is not done yet */
2309 			return 1;
2310 		return ((cqr->status != DASD_CQR_DONE) &&
2311 			(cqr->status != DASD_CQR_FAILED));
2312 	} else
2313 		return (cqr->status == DASD_CQR_FILLED);
2314 }
2315 
_dasd_sleep_on(struct dasd_ccw_req * maincqr,int interruptible)2316 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2317 {
2318 	struct dasd_device *device;
2319 	int rc;
2320 	struct list_head ccw_queue;
2321 	struct dasd_ccw_req *cqr;
2322 
2323 	INIT_LIST_HEAD(&ccw_queue);
2324 	maincqr->status = DASD_CQR_FILLED;
2325 	device = maincqr->startdev;
2326 	list_add(&maincqr->blocklist, &ccw_queue);
2327 	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2328 	     cqr = list_first_entry(&ccw_queue,
2329 				    struct dasd_ccw_req, blocklist)) {
2330 
2331 		if (__dasd_sleep_on_erp(cqr))
2332 			continue;
2333 		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2334 			continue;
2335 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2336 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2337 			cqr->status = DASD_CQR_FAILED;
2338 			cqr->intrc = -EPERM;
2339 			continue;
2340 		}
2341 		/* Non-temporary stop condition will trigger fail fast */
2342 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2343 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2344 		    !dasd_eer_enabled(device) && device->aq_mask == 0) {
2345 			cqr->status = DASD_CQR_FAILED;
2346 			cqr->intrc = -ENOLINK;
2347 			continue;
2348 		}
2349 		/*
2350 		 * Don't try to start requests if device is in
2351 		 * offline processing, it might wait forever
2352 		 */
2353 		if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2354 			cqr->status = DASD_CQR_FAILED;
2355 			cqr->intrc = -ENODEV;
2356 			continue;
2357 		}
2358 		/*
2359 		 * Don't try to start requests if device is stopped
2360 		 * except path verification requests
2361 		 */
2362 		if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2363 			if (interruptible) {
2364 				rc = wait_event_interruptible(
2365 					generic_waitq, !(device->stopped));
2366 				if (rc == -ERESTARTSYS) {
2367 					cqr->status = DASD_CQR_FAILED;
2368 					maincqr->intrc = rc;
2369 					continue;
2370 				}
2371 			} else
2372 				wait_event(generic_waitq, !(device->stopped));
2373 		}
2374 		if (!cqr->callback)
2375 			cqr->callback = dasd_wakeup_cb;
2376 
2377 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2378 		dasd_add_request_tail(cqr);
2379 		if (interruptible) {
2380 			rc = wait_event_interruptible(
2381 				generic_waitq, _wait_for_wakeup(cqr));
2382 			if (rc == -ERESTARTSYS) {
2383 				dasd_cancel_req(cqr);
2384 				/* wait (non-interruptible) for final status */
2385 				wait_event(generic_waitq,
2386 					   _wait_for_wakeup(cqr));
2387 				cqr->status = DASD_CQR_FAILED;
2388 				maincqr->intrc = rc;
2389 				continue;
2390 			}
2391 		} else
2392 			wait_event(generic_waitq, _wait_for_wakeup(cqr));
2393 	}
2394 
2395 	maincqr->endclk = get_tod_clock();
2396 	if ((maincqr->status != DASD_CQR_DONE) &&
2397 	    (maincqr->intrc != -ERESTARTSYS))
2398 		dasd_log_sense(maincqr, &maincqr->irb);
2399 	if (maincqr->status == DASD_CQR_DONE)
2400 		rc = 0;
2401 	else if (maincqr->intrc)
2402 		rc = maincqr->intrc;
2403 	else
2404 		rc = -EIO;
2405 	return rc;
2406 }
2407 
_wait_for_wakeup_queue(struct list_head * ccw_queue)2408 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2409 {
2410 	struct dasd_ccw_req *cqr;
2411 
2412 	list_for_each_entry(cqr, ccw_queue, blocklist) {
2413 		if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2414 			return 0;
2415 	}
2416 
2417 	return 1;
2418 }
2419 
_dasd_sleep_on_queue(struct list_head * ccw_queue,int interruptible)2420 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2421 {
2422 	struct dasd_device *device;
2423 	struct dasd_ccw_req *cqr, *n;
2424 	u8 *sense = NULL;
2425 	int rc;
2426 
2427 retry:
2428 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2429 		device = cqr->startdev;
2430 		if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2431 			continue;
2432 
2433 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2434 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2435 			cqr->status = DASD_CQR_FAILED;
2436 			cqr->intrc = -EPERM;
2437 			continue;
2438 		}
2439 		/*Non-temporary stop condition will trigger fail fast*/
2440 		if (device->stopped & ~DASD_STOPPED_PENDING &&
2441 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2442 		    !dasd_eer_enabled(device)) {
2443 			cqr->status = DASD_CQR_FAILED;
2444 			cqr->intrc = -EAGAIN;
2445 			continue;
2446 		}
2447 
2448 		/*Don't try to start requests if device is stopped*/
2449 		if (interruptible) {
2450 			rc = wait_event_interruptible(
2451 				generic_waitq, !device->stopped);
2452 			if (rc == -ERESTARTSYS) {
2453 				cqr->status = DASD_CQR_FAILED;
2454 				cqr->intrc = rc;
2455 				continue;
2456 			}
2457 		} else
2458 			wait_event(generic_waitq, !(device->stopped));
2459 
2460 		if (!cqr->callback)
2461 			cqr->callback = dasd_wakeup_cb;
2462 		cqr->callback_data = DASD_SLEEPON_START_TAG;
2463 		dasd_add_request_tail(cqr);
2464 	}
2465 
2466 	wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2467 
2468 	rc = 0;
2469 	list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2470 		/*
2471 		 * In some cases the 'File Protected' or 'Incorrect Length'
2472 		 * error might be expected and error recovery would be
2473 		 * unnecessary in these cases.	Check if the according suppress
2474 		 * bit is set.
2475 		 */
2476 		sense = dasd_get_sense(&cqr->irb);
2477 		if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2478 		    test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2479 			continue;
2480 		if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2481 		    test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2482 			continue;
2483 
2484 		/*
2485 		 * for alias devices simplify error recovery and
2486 		 * return to upper layer
2487 		 * do not skip ERP requests
2488 		 */
2489 		if (cqr->startdev != cqr->basedev && !cqr->refers &&
2490 		    (cqr->status == DASD_CQR_TERMINATED ||
2491 		     cqr->status == DASD_CQR_NEED_ERP))
2492 			return -EAGAIN;
2493 
2494 		/* normal recovery for basedev IO */
2495 		if (__dasd_sleep_on_erp(cqr))
2496 			/* handle erp first */
2497 			goto retry;
2498 	}
2499 
2500 	return 0;
2501 }
2502 
2503 /*
2504  * Queue a request to the tail of the device ccw_queue and wait for
2505  * it's completion.
2506  */
dasd_sleep_on(struct dasd_ccw_req * cqr)2507 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2508 {
2509 	return _dasd_sleep_on(cqr, 0);
2510 }
2511 EXPORT_SYMBOL(dasd_sleep_on);
2512 
2513 /*
2514  * Start requests from a ccw_queue and wait for their completion.
2515  */
dasd_sleep_on_queue(struct list_head * ccw_queue)2516 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2517 {
2518 	return _dasd_sleep_on_queue(ccw_queue, 0);
2519 }
2520 EXPORT_SYMBOL(dasd_sleep_on_queue);
2521 
2522 /*
2523  * Start requests from a ccw_queue and wait interruptible for their completion.
2524  */
dasd_sleep_on_queue_interruptible(struct list_head * ccw_queue)2525 int dasd_sleep_on_queue_interruptible(struct list_head *ccw_queue)
2526 {
2527 	return _dasd_sleep_on_queue(ccw_queue, 1);
2528 }
2529 EXPORT_SYMBOL(dasd_sleep_on_queue_interruptible);
2530 
2531 /*
2532  * Queue a request to the tail of the device ccw_queue and wait
2533  * interruptible for it's completion.
2534  */
dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)2535 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2536 {
2537 	return _dasd_sleep_on(cqr, 1);
2538 }
2539 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2540 
2541 /*
2542  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2543  * for eckd devices) the currently running request has to be terminated
2544  * and be put back to status queued, before the special request is added
2545  * to the head of the queue. Then the special request is waited on normally.
2546  */
_dasd_term_running_cqr(struct dasd_device * device)2547 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2548 {
2549 	struct dasd_ccw_req *cqr;
2550 	int rc;
2551 
2552 	if (list_empty(&device->ccw_queue))
2553 		return 0;
2554 	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2555 	rc = device->discipline->term_IO(cqr);
2556 	if (!rc)
2557 		/*
2558 		 * CQR terminated because a more important request is pending.
2559 		 * Undo decreasing of retry counter because this is
2560 		 * not an error case.
2561 		 */
2562 		cqr->retries++;
2563 	return rc;
2564 }
2565 
dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)2566 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2567 {
2568 	struct dasd_device *device;
2569 	int rc;
2570 
2571 	device = cqr->startdev;
2572 	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2573 	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2574 		cqr->status = DASD_CQR_FAILED;
2575 		cqr->intrc = -EPERM;
2576 		return -EIO;
2577 	}
2578 	spin_lock_irq(get_ccwdev_lock(device->cdev));
2579 	rc = _dasd_term_running_cqr(device);
2580 	if (rc) {
2581 		spin_unlock_irq(get_ccwdev_lock(device->cdev));
2582 		return rc;
2583 	}
2584 	cqr->callback = dasd_wakeup_cb;
2585 	cqr->callback_data = DASD_SLEEPON_START_TAG;
2586 	cqr->status = DASD_CQR_QUEUED;
2587 	/*
2588 	 * add new request as second
2589 	 * first the terminated cqr needs to be finished
2590 	 */
2591 	list_add(&cqr->devlist, device->ccw_queue.next);
2592 
2593 	/* let the bh start the request to keep them in order */
2594 	dasd_schedule_device_bh(device);
2595 
2596 	spin_unlock_irq(get_ccwdev_lock(device->cdev));
2597 
2598 	wait_event(generic_waitq, _wait_for_wakeup(cqr));
2599 
2600 	if (cqr->status == DASD_CQR_DONE)
2601 		rc = 0;
2602 	else if (cqr->intrc)
2603 		rc = cqr->intrc;
2604 	else
2605 		rc = -EIO;
2606 
2607 	/* kick tasklets */
2608 	dasd_schedule_device_bh(device);
2609 	if (device->block)
2610 		dasd_schedule_block_bh(device->block);
2611 
2612 	return rc;
2613 }
2614 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2615 
2616 /*
2617  * Cancels a request that was started with dasd_sleep_on_req.
2618  * This is useful to timeout requests. The request will be
2619  * terminated if it is currently in i/o.
2620  * Returns 0 if request termination was successful
2621  *	   negative error code if termination failed
2622  * Cancellation of a request is an asynchronous operation! The calling
2623  * function has to wait until the request is properly returned via callback.
2624  */
__dasd_cancel_req(struct dasd_ccw_req * cqr)2625 static int __dasd_cancel_req(struct dasd_ccw_req *cqr)
2626 {
2627 	struct dasd_device *device = cqr->startdev;
2628 	int rc = 0;
2629 
2630 	switch (cqr->status) {
2631 	case DASD_CQR_QUEUED:
2632 		/* request was not started - just set to cleared */
2633 		cqr->status = DASD_CQR_CLEARED;
2634 		break;
2635 	case DASD_CQR_IN_IO:
2636 		/* request in IO - terminate IO and release again */
2637 		rc = device->discipline->term_IO(cqr);
2638 		if (rc) {
2639 			dev_err(&device->cdev->dev,
2640 				"Cancelling request %p failed with rc=%d\n",
2641 				cqr, rc);
2642 		} else {
2643 			cqr->stopclk = get_tod_clock();
2644 		}
2645 		break;
2646 	default: /* already finished or clear pending - do nothing */
2647 		break;
2648 	}
2649 	dasd_schedule_device_bh(device);
2650 	return rc;
2651 }
2652 
dasd_cancel_req(struct dasd_ccw_req * cqr)2653 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2654 {
2655 	struct dasd_device *device = cqr->startdev;
2656 	unsigned long flags;
2657 	int rc;
2658 
2659 	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2660 	rc = __dasd_cancel_req(cqr);
2661 	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2662 	return rc;
2663 }
2664 
2665 /*
2666  * SECTION: Operations of the dasd_block layer.
2667  */
2668 
2669 /*
2670  * Timeout function for dasd_block. This is used when the block layer
2671  * is waiting for something that may not come reliably, (e.g. a state
2672  * change interrupt)
2673  */
dasd_block_timeout(struct timer_list * t)2674 static void dasd_block_timeout(struct timer_list *t)
2675 {
2676 	unsigned long flags;
2677 	struct dasd_block *block;
2678 
2679 	block = from_timer(block, t, timer);
2680 	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2681 	/* re-activate request queue */
2682 	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2683 	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2684 	dasd_schedule_block_bh(block);
2685 	blk_mq_run_hw_queues(block->gdp->queue, true);
2686 }
2687 
2688 /*
2689  * Setup timeout for a dasd_block in jiffies.
2690  */
dasd_block_set_timer(struct dasd_block * block,int expires)2691 void dasd_block_set_timer(struct dasd_block *block, int expires)
2692 {
2693 	if (expires == 0)
2694 		del_timer(&block->timer);
2695 	else
2696 		mod_timer(&block->timer, jiffies + expires);
2697 }
2698 EXPORT_SYMBOL(dasd_block_set_timer);
2699 
2700 /*
2701  * Clear timeout for a dasd_block.
2702  */
dasd_block_clear_timer(struct dasd_block * block)2703 void dasd_block_clear_timer(struct dasd_block *block)
2704 {
2705 	del_timer(&block->timer);
2706 }
2707 EXPORT_SYMBOL(dasd_block_clear_timer);
2708 
2709 /*
2710  * Process finished error recovery ccw.
2711  */
__dasd_process_erp(struct dasd_device * device,struct dasd_ccw_req * cqr)2712 static void __dasd_process_erp(struct dasd_device *device,
2713 			       struct dasd_ccw_req *cqr)
2714 {
2715 	dasd_erp_fn_t erp_fn;
2716 
2717 	if (cqr->status == DASD_CQR_DONE)
2718 		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2719 	else
2720 		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2721 	erp_fn = device->discipline->erp_postaction(cqr);
2722 	erp_fn(cqr);
2723 }
2724 
__dasd_cleanup_cqr(struct dasd_ccw_req * cqr)2725 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2726 {
2727 	struct request *req;
2728 	blk_status_t error = BLK_STS_OK;
2729 	unsigned int proc_bytes;
2730 	int status;
2731 
2732 	req = (struct request *) cqr->callback_data;
2733 	dasd_profile_end(cqr->block, cqr, req);
2734 
2735 	proc_bytes = cqr->proc_bytes;
2736 	status = cqr->block->base->discipline->free_cp(cqr, req);
2737 	if (status < 0)
2738 		error = errno_to_blk_status(status);
2739 	else if (status == 0) {
2740 		switch (cqr->intrc) {
2741 		case -EPERM:
2742 			/*
2743 			 * DASD doesn't implement SCSI/NVMe reservations, but it
2744 			 * implements a locking scheme similar to them. We
2745 			 * return this error when we no longer have the lock.
2746 			 */
2747 			error = BLK_STS_RESV_CONFLICT;
2748 			break;
2749 		case -ENOLINK:
2750 			error = BLK_STS_TRANSPORT;
2751 			break;
2752 		case -ETIMEDOUT:
2753 			error = BLK_STS_TIMEOUT;
2754 			break;
2755 		default:
2756 			error = BLK_STS_IOERR;
2757 			break;
2758 		}
2759 	}
2760 
2761 	/*
2762 	 * We need to take care for ETIMEDOUT errors here since the
2763 	 * complete callback does not get called in this case.
2764 	 * Take care of all errors here and avoid additional code to
2765 	 * transfer the error value to the complete callback.
2766 	 */
2767 	if (error) {
2768 		blk_mq_end_request(req, error);
2769 		blk_mq_run_hw_queues(req->q, true);
2770 	} else {
2771 		/*
2772 		 * Partial completed requests can happen with ESE devices.
2773 		 * During read we might have gotten a NRF error and have to
2774 		 * complete a request partially.
2775 		 */
2776 		if (proc_bytes) {
2777 			blk_update_request(req, BLK_STS_OK, proc_bytes);
2778 			blk_mq_requeue_request(req, true);
2779 		} else if (likely(!blk_should_fake_timeout(req->q))) {
2780 			blk_mq_complete_request(req);
2781 		}
2782 	}
2783 }
2784 
2785 /*
2786  * Process ccw request queue.
2787  */
__dasd_process_block_ccw_queue(struct dasd_block * block,struct list_head * final_queue)2788 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2789 					   struct list_head *final_queue)
2790 {
2791 	struct list_head *l, *n;
2792 	struct dasd_ccw_req *cqr;
2793 	dasd_erp_fn_t erp_fn;
2794 	unsigned long flags;
2795 	struct dasd_device *base = block->base;
2796 
2797 restart:
2798 	/* Process request with final status. */
2799 	list_for_each_safe(l, n, &block->ccw_queue) {
2800 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2801 		if (cqr->status != DASD_CQR_DONE &&
2802 		    cqr->status != DASD_CQR_FAILED &&
2803 		    cqr->status != DASD_CQR_NEED_ERP &&
2804 		    cqr->status != DASD_CQR_TERMINATED)
2805 			continue;
2806 
2807 		if (cqr->status == DASD_CQR_TERMINATED) {
2808 			base->discipline->handle_terminated_request(cqr);
2809 			goto restart;
2810 		}
2811 
2812 		/*  Process requests that may be recovered */
2813 		if (cqr->status == DASD_CQR_NEED_ERP) {
2814 			erp_fn = base->discipline->erp_action(cqr);
2815 			if (IS_ERR(erp_fn(cqr)))
2816 				continue;
2817 			goto restart;
2818 		}
2819 
2820 		/* log sense for fatal error */
2821 		if (cqr->status == DASD_CQR_FAILED) {
2822 			dasd_log_sense(cqr, &cqr->irb);
2823 		}
2824 
2825 		/*
2826 		 * First call extended error reporting and check for autoquiesce
2827 		 */
2828 		spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2829 		if (cqr->status == DASD_CQR_FAILED &&
2830 		    dasd_handle_autoquiesce(base, cqr, DASD_EER_FATALERROR)) {
2831 			cqr->status = DASD_CQR_FILLED;
2832 			cqr->retries = 255;
2833 			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
2834 			goto restart;
2835 		}
2836 		spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
2837 
2838 		/* Process finished ERP request. */
2839 		if (cqr->refers) {
2840 			__dasd_process_erp(base, cqr);
2841 			goto restart;
2842 		}
2843 
2844 		/* Rechain finished requests to final queue */
2845 		cqr->endclk = get_tod_clock();
2846 		list_move_tail(&cqr->blocklist, final_queue);
2847 	}
2848 }
2849 
dasd_return_cqr_cb(struct dasd_ccw_req * cqr,void * data)2850 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2851 {
2852 	dasd_schedule_block_bh(cqr->block);
2853 }
2854 
__dasd_block_start_head(struct dasd_block * block)2855 static void __dasd_block_start_head(struct dasd_block *block)
2856 {
2857 	struct dasd_ccw_req *cqr;
2858 
2859 	if (list_empty(&block->ccw_queue))
2860 		return;
2861 	/* We allways begin with the first requests on the queue, as some
2862 	 * of previously started requests have to be enqueued on a
2863 	 * dasd_device again for error recovery.
2864 	 */
2865 	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2866 		if (cqr->status != DASD_CQR_FILLED)
2867 			continue;
2868 		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2869 		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2870 			cqr->status = DASD_CQR_FAILED;
2871 			cqr->intrc = -EPERM;
2872 			dasd_schedule_block_bh(block);
2873 			continue;
2874 		}
2875 		/* Non-temporary stop condition will trigger fail fast */
2876 		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2877 		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2878 		    !dasd_eer_enabled(block->base) && block->base->aq_mask == 0) {
2879 			cqr->status = DASD_CQR_FAILED;
2880 			cqr->intrc = -ENOLINK;
2881 			dasd_schedule_block_bh(block);
2882 			continue;
2883 		}
2884 		/* Don't try to start requests if device is stopped */
2885 		if (block->base->stopped)
2886 			return;
2887 
2888 		/* just a fail safe check, should not happen */
2889 		if (!cqr->startdev)
2890 			cqr->startdev = block->base;
2891 
2892 		/* make sure that the requests we submit find their way back */
2893 		cqr->callback = dasd_return_cqr_cb;
2894 
2895 		dasd_add_request_tail(cqr);
2896 	}
2897 }
2898 
2899 /*
2900  * Central dasd_block layer routine. Takes requests from the generic
2901  * block layer request queue, creates ccw requests, enqueues them on
2902  * a dasd_device and processes ccw requests that have been returned.
2903  */
dasd_block_tasklet(unsigned long data)2904 static void dasd_block_tasklet(unsigned long data)
2905 {
2906 	struct dasd_block *block = (struct dasd_block *) data;
2907 	struct list_head final_queue;
2908 	struct list_head *l, *n;
2909 	struct dasd_ccw_req *cqr;
2910 	struct dasd_queue *dq;
2911 
2912 	atomic_set(&block->tasklet_scheduled, 0);
2913 	INIT_LIST_HEAD(&final_queue);
2914 	spin_lock_irq(&block->queue_lock);
2915 	/* Finish off requests on ccw queue */
2916 	__dasd_process_block_ccw_queue(block, &final_queue);
2917 	spin_unlock_irq(&block->queue_lock);
2918 
2919 	/* Now call the callback function of requests with final status */
2920 	list_for_each_safe(l, n, &final_queue) {
2921 		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2922 		dq = cqr->dq;
2923 		spin_lock_irq(&dq->lock);
2924 		list_del_init(&cqr->blocklist);
2925 		__dasd_cleanup_cqr(cqr);
2926 		spin_unlock_irq(&dq->lock);
2927 	}
2928 
2929 	spin_lock_irq(&block->queue_lock);
2930 	/* Now check if the head of the ccw queue needs to be started. */
2931 	__dasd_block_start_head(block);
2932 	spin_unlock_irq(&block->queue_lock);
2933 
2934 	if (waitqueue_active(&shutdown_waitq))
2935 		wake_up(&shutdown_waitq);
2936 	dasd_put_device(block->base);
2937 }
2938 
_dasd_wake_block_flush_cb(struct dasd_ccw_req * cqr,void * data)2939 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2940 {
2941 	wake_up(&dasd_flush_wq);
2942 }
2943 
2944 /*
2945  * Requeue a request back to the block request queue
2946  * only works for block requests
2947  */
_dasd_requeue_request(struct dasd_ccw_req * cqr)2948 static void _dasd_requeue_request(struct dasd_ccw_req *cqr)
2949 {
2950 	struct request *req;
2951 
2952 	/*
2953 	 * If the request is an ERP request there is nothing to requeue.
2954 	 * This will be done with the remaining original request.
2955 	 */
2956 	if (cqr->refers)
2957 		return;
2958 	spin_lock_irq(&cqr->dq->lock);
2959 	req = (struct request *) cqr->callback_data;
2960 	blk_mq_requeue_request(req, true);
2961 	spin_unlock_irq(&cqr->dq->lock);
2962 
2963 	return;
2964 }
2965 
_dasd_requests_to_flushqueue(struct dasd_block * block,struct list_head * flush_queue)2966 static int _dasd_requests_to_flushqueue(struct dasd_block *block,
2967 					struct list_head *flush_queue)
2968 {
2969 	struct dasd_ccw_req *cqr, *n;
2970 	unsigned long flags;
2971 	int rc, i;
2972 
2973 	spin_lock_irqsave(&block->queue_lock, flags);
2974 	rc = 0;
2975 restart:
2976 	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2977 		/* if this request currently owned by a dasd_device cancel it */
2978 		if (cqr->status >= DASD_CQR_QUEUED)
2979 			rc = dasd_cancel_req(cqr);
2980 		if (rc < 0)
2981 			break;
2982 		/* Rechain request (including erp chain) so it won't be
2983 		 * touched by the dasd_block_tasklet anymore.
2984 		 * Replace the callback so we notice when the request
2985 		 * is returned from the dasd_device layer.
2986 		 */
2987 		cqr->callback = _dasd_wake_block_flush_cb;
2988 		for (i = 0; cqr; cqr = cqr->refers, i++)
2989 			list_move_tail(&cqr->blocklist, flush_queue);
2990 		if (i > 1)
2991 			/* moved more than one request - need to restart */
2992 			goto restart;
2993 	}
2994 	spin_unlock_irqrestore(&block->queue_lock, flags);
2995 
2996 	return rc;
2997 }
2998 
2999 /*
3000  * Go through all request on the dasd_block request queue, cancel them
3001  * on the respective dasd_device, and return them to the generic
3002  * block layer.
3003  */
dasd_flush_block_queue(struct dasd_block * block)3004 static int dasd_flush_block_queue(struct dasd_block *block)
3005 {
3006 	struct dasd_ccw_req *cqr, *n;
3007 	struct list_head flush_queue;
3008 	unsigned long flags;
3009 	int rc;
3010 
3011 	INIT_LIST_HEAD(&flush_queue);
3012 	rc = _dasd_requests_to_flushqueue(block, &flush_queue);
3013 
3014 	/* Now call the callback function of flushed requests */
3015 restart_cb:
3016 	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
3017 		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3018 		/* Process finished ERP request. */
3019 		if (cqr->refers) {
3020 			spin_lock_bh(&block->queue_lock);
3021 			__dasd_process_erp(block->base, cqr);
3022 			spin_unlock_bh(&block->queue_lock);
3023 			/* restart list_for_xx loop since dasd_process_erp
3024 			 * might remove multiple elements */
3025 			goto restart_cb;
3026 		}
3027 		/* call the callback function */
3028 		spin_lock_irqsave(&cqr->dq->lock, flags);
3029 		cqr->endclk = get_tod_clock();
3030 		list_del_init(&cqr->blocklist);
3031 		__dasd_cleanup_cqr(cqr);
3032 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3033 	}
3034 	return rc;
3035 }
3036 
3037 /*
3038  * Schedules a call to dasd_tasklet over the device tasklet.
3039  */
dasd_schedule_block_bh(struct dasd_block * block)3040 void dasd_schedule_block_bh(struct dasd_block *block)
3041 {
3042 	/* Protect against rescheduling. */
3043 	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
3044 		return;
3045 	/* life cycle of block is bound to it's base device */
3046 	dasd_get_device(block->base);
3047 	tasklet_hi_schedule(&block->tasklet);
3048 }
3049 EXPORT_SYMBOL(dasd_schedule_block_bh);
3050 
3051 
3052 /*
3053  * SECTION: external block device operations
3054  * (request queue handling, open, release, etc.)
3055  */
3056 
3057 /*
3058  * Dasd request queue function. Called from ll_rw_blk.c
3059  */
do_dasd_request(struct blk_mq_hw_ctx * hctx,const struct blk_mq_queue_data * qd)3060 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
3061 				    const struct blk_mq_queue_data *qd)
3062 {
3063 	struct dasd_block *block = hctx->queue->queuedata;
3064 	struct dasd_queue *dq = hctx->driver_data;
3065 	struct request *req = qd->rq;
3066 	struct dasd_device *basedev;
3067 	struct dasd_ccw_req *cqr;
3068 	blk_status_t rc = BLK_STS_OK;
3069 
3070 	basedev = block->base;
3071 	spin_lock_irq(&dq->lock);
3072 	if (basedev->state < DASD_STATE_READY ||
3073 	    test_bit(DASD_FLAG_OFFLINE, &basedev->flags)) {
3074 		DBF_DEV_EVENT(DBF_ERR, basedev,
3075 			      "device not ready for request %p", req);
3076 		rc = BLK_STS_IOERR;
3077 		goto out;
3078 	}
3079 
3080 	/*
3081 	 * if device is stopped do not fetch new requests
3082 	 * except failfast is active which will let requests fail
3083 	 * immediately in __dasd_block_start_head()
3084 	 */
3085 	if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
3086 		DBF_DEV_EVENT(DBF_ERR, basedev,
3087 			      "device stopped request %p", req);
3088 		rc = BLK_STS_RESOURCE;
3089 		goto out;
3090 	}
3091 
3092 	if (basedev->features & DASD_FEATURE_READONLY &&
3093 	    rq_data_dir(req) == WRITE) {
3094 		DBF_DEV_EVENT(DBF_ERR, basedev,
3095 			      "Rejecting write request %p", req);
3096 		rc = BLK_STS_IOERR;
3097 		goto out;
3098 	}
3099 
3100 	if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3101 	    (basedev->features & DASD_FEATURE_FAILFAST ||
3102 	     blk_noretry_request(req))) {
3103 		DBF_DEV_EVENT(DBF_ERR, basedev,
3104 			      "Rejecting failfast request %p", req);
3105 		rc = BLK_STS_IOERR;
3106 		goto out;
3107 	}
3108 
3109 	cqr = basedev->discipline->build_cp(basedev, block, req);
3110 	if (IS_ERR(cqr)) {
3111 		if (PTR_ERR(cqr) == -EBUSY ||
3112 		    PTR_ERR(cqr) == -ENOMEM ||
3113 		    PTR_ERR(cqr) == -EAGAIN) {
3114 			rc = BLK_STS_RESOURCE;
3115 			goto out;
3116 		}
3117 		DBF_DEV_EVENT(DBF_ERR, basedev,
3118 			      "CCW creation failed (rc=%ld) on request %p",
3119 			      PTR_ERR(cqr), req);
3120 		rc = BLK_STS_IOERR;
3121 		goto out;
3122 	}
3123 	/*
3124 	 *  Note: callback is set to dasd_return_cqr_cb in
3125 	 * __dasd_block_start_head to cover erp requests as well
3126 	 */
3127 	cqr->callback_data = req;
3128 	cqr->status = DASD_CQR_FILLED;
3129 	cqr->dq = dq;
3130 
3131 	blk_mq_start_request(req);
3132 	spin_lock(&block->queue_lock);
3133 	list_add_tail(&cqr->blocklist, &block->ccw_queue);
3134 	INIT_LIST_HEAD(&cqr->devlist);
3135 	dasd_profile_start(block, cqr, req);
3136 	dasd_schedule_block_bh(block);
3137 	spin_unlock(&block->queue_lock);
3138 
3139 out:
3140 	spin_unlock_irq(&dq->lock);
3141 	return rc;
3142 }
3143 
3144 /*
3145  * Block timeout callback, called from the block layer
3146  *
3147  * Return values:
3148  * BLK_EH_RESET_TIMER if the request should be left running
3149  * BLK_EH_DONE if the request is handled or terminated
3150  *		      by the driver.
3151  */
dasd_times_out(struct request * req)3152 enum blk_eh_timer_return dasd_times_out(struct request *req)
3153 {
3154 	struct dasd_block *block = req->q->queuedata;
3155 	struct dasd_device *device;
3156 	struct dasd_ccw_req *cqr;
3157 	unsigned long flags;
3158 	int rc = 0;
3159 
3160 	cqr = blk_mq_rq_to_pdu(req);
3161 	if (!cqr)
3162 		return BLK_EH_DONE;
3163 
3164 	spin_lock_irqsave(&cqr->dq->lock, flags);
3165 	device = cqr->startdev ? cqr->startdev : block->base;
3166 	if (!device->blk_timeout) {
3167 		spin_unlock_irqrestore(&cqr->dq->lock, flags);
3168 		return BLK_EH_RESET_TIMER;
3169 	}
3170 	DBF_DEV_EVENT(DBF_WARNING, device,
3171 		      " dasd_times_out cqr %p status %x",
3172 		      cqr, cqr->status);
3173 
3174 	spin_lock(&block->queue_lock);
3175 	spin_lock(get_ccwdev_lock(device->cdev));
3176 	cqr->retries = -1;
3177 	cqr->intrc = -ETIMEDOUT;
3178 	if (cqr->status >= DASD_CQR_QUEUED) {
3179 		rc = __dasd_cancel_req(cqr);
3180 	} else if (cqr->status == DASD_CQR_FILLED ||
3181 		   cqr->status == DASD_CQR_NEED_ERP) {
3182 		cqr->status = DASD_CQR_TERMINATED;
3183 	} else if (cqr->status == DASD_CQR_IN_ERP) {
3184 		struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3185 
3186 		list_for_each_entry_safe(searchcqr, nextcqr,
3187 					 &block->ccw_queue, blocklist) {
3188 			tmpcqr = searchcqr;
3189 			while (tmpcqr->refers)
3190 				tmpcqr = tmpcqr->refers;
3191 			if (tmpcqr != cqr)
3192 				continue;
3193 			/* searchcqr is an ERP request for cqr */
3194 			searchcqr->retries = -1;
3195 			searchcqr->intrc = -ETIMEDOUT;
3196 			if (searchcqr->status >= DASD_CQR_QUEUED) {
3197 				rc = __dasd_cancel_req(searchcqr);
3198 			} else if ((searchcqr->status == DASD_CQR_FILLED) ||
3199 				   (searchcqr->status == DASD_CQR_NEED_ERP)) {
3200 				searchcqr->status = DASD_CQR_TERMINATED;
3201 				rc = 0;
3202 			} else if (searchcqr->status == DASD_CQR_IN_ERP) {
3203 				/*
3204 				 * Shouldn't happen; most recent ERP
3205 				 * request is at the front of queue
3206 				 */
3207 				continue;
3208 			}
3209 			break;
3210 		}
3211 	}
3212 	spin_unlock(get_ccwdev_lock(device->cdev));
3213 	dasd_schedule_block_bh(block);
3214 	spin_unlock(&block->queue_lock);
3215 	spin_unlock_irqrestore(&cqr->dq->lock, flags);
3216 
3217 	return rc ? BLK_EH_RESET_TIMER : BLK_EH_DONE;
3218 }
3219 
dasd_init_hctx(struct blk_mq_hw_ctx * hctx,void * data,unsigned int idx)3220 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3221 			  unsigned int idx)
3222 {
3223 	struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3224 
3225 	if (!dq)
3226 		return -ENOMEM;
3227 
3228 	spin_lock_init(&dq->lock);
3229 	hctx->driver_data = dq;
3230 
3231 	return 0;
3232 }
3233 
dasd_exit_hctx(struct blk_mq_hw_ctx * hctx,unsigned int idx)3234 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3235 {
3236 	kfree(hctx->driver_data);
3237 	hctx->driver_data = NULL;
3238 }
3239 
dasd_request_done(struct request * req)3240 static void dasd_request_done(struct request *req)
3241 {
3242 	blk_mq_end_request(req, 0);
3243 	blk_mq_run_hw_queues(req->q, true);
3244 }
3245 
3246 struct blk_mq_ops dasd_mq_ops = {
3247 	.queue_rq = do_dasd_request,
3248 	.complete = dasd_request_done,
3249 	.timeout = dasd_times_out,
3250 	.init_hctx = dasd_init_hctx,
3251 	.exit_hctx = dasd_exit_hctx,
3252 };
3253 
dasd_open(struct gendisk * disk,blk_mode_t mode)3254 static int dasd_open(struct gendisk *disk, blk_mode_t mode)
3255 {
3256 	struct dasd_device *base;
3257 	int rc;
3258 
3259 	base = dasd_device_from_gendisk(disk);
3260 	if (!base)
3261 		return -ENODEV;
3262 
3263 	atomic_inc(&base->block->open_count);
3264 	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3265 		rc = -ENODEV;
3266 		goto unlock;
3267 	}
3268 
3269 	if (!try_module_get(base->discipline->owner)) {
3270 		rc = -EINVAL;
3271 		goto unlock;
3272 	}
3273 
3274 	if (dasd_probeonly) {
3275 		dev_info(&base->cdev->dev,
3276 			 "Accessing the DASD failed because it is in "
3277 			 "probeonly mode\n");
3278 		rc = -EPERM;
3279 		goto out;
3280 	}
3281 
3282 	if (base->state <= DASD_STATE_BASIC) {
3283 		DBF_DEV_EVENT(DBF_ERR, base, " %s",
3284 			      " Cannot open unrecognized device");
3285 		rc = -ENODEV;
3286 		goto out;
3287 	}
3288 	if ((mode & BLK_OPEN_WRITE) &&
3289 	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3290 	     (base->features & DASD_FEATURE_READONLY))) {
3291 		rc = -EROFS;
3292 		goto out;
3293 	}
3294 	dasd_put_device(base);
3295 	return 0;
3296 
3297 out:
3298 	module_put(base->discipline->owner);
3299 unlock:
3300 	atomic_dec(&base->block->open_count);
3301 	dasd_put_device(base);
3302 	return rc;
3303 }
3304 
dasd_release(struct gendisk * disk)3305 static void dasd_release(struct gendisk *disk)
3306 {
3307 	struct dasd_device *base = dasd_device_from_gendisk(disk);
3308 	if (base) {
3309 		atomic_dec(&base->block->open_count);
3310 		module_put(base->discipline->owner);
3311 		dasd_put_device(base);
3312 	}
3313 }
3314 
3315 /*
3316  * Return disk geometry.
3317  */
dasd_getgeo(struct block_device * bdev,struct hd_geometry * geo)3318 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3319 {
3320 	struct dasd_device *base;
3321 
3322 	base = dasd_device_from_gendisk(bdev->bd_disk);
3323 	if (!base)
3324 		return -ENODEV;
3325 
3326 	if (!base->discipline ||
3327 	    !base->discipline->fill_geometry) {
3328 		dasd_put_device(base);
3329 		return -EINVAL;
3330 	}
3331 	base->discipline->fill_geometry(base->block, geo);
3332 	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3333 	dasd_put_device(base);
3334 	return 0;
3335 }
3336 
3337 const struct block_device_operations
3338 dasd_device_operations = {
3339 	.owner		= THIS_MODULE,
3340 	.open		= dasd_open,
3341 	.release	= dasd_release,
3342 	.ioctl		= dasd_ioctl,
3343 	.compat_ioctl	= dasd_ioctl,
3344 	.getgeo		= dasd_getgeo,
3345 	.set_read_only	= dasd_set_read_only,
3346 };
3347 
3348 /*******************************************************************************
3349  * end of block device operations
3350  */
3351 
3352 static void
dasd_exit(void)3353 dasd_exit(void)
3354 {
3355 #ifdef CONFIG_PROC_FS
3356 	dasd_proc_exit();
3357 #endif
3358 	dasd_eer_exit();
3359 	kmem_cache_destroy(dasd_page_cache);
3360 	dasd_page_cache = NULL;
3361 	dasd_gendisk_exit();
3362 	dasd_devmap_exit();
3363 	if (dasd_debug_area != NULL) {
3364 		debug_unregister(dasd_debug_area);
3365 		dasd_debug_area = NULL;
3366 	}
3367 	dasd_statistics_removeroot();
3368 }
3369 
3370 /*
3371  * SECTION: common functions for ccw_driver use
3372  */
3373 
3374 /*
3375  * Is the device read-only?
3376  * Note that this function does not report the setting of the
3377  * readonly device attribute, but how it is configured in z/VM.
3378  */
dasd_device_is_ro(struct dasd_device * device)3379 int dasd_device_is_ro(struct dasd_device *device)
3380 {
3381 	struct ccw_dev_id dev_id;
3382 	struct diag210 diag_data;
3383 	int rc;
3384 
3385 	if (!MACHINE_IS_VM)
3386 		return 0;
3387 	ccw_device_get_id(device->cdev, &dev_id);
3388 	memset(&diag_data, 0, sizeof(diag_data));
3389 	diag_data.vrdcdvno = dev_id.devno;
3390 	diag_data.vrdclen = sizeof(diag_data);
3391 	rc = diag210(&diag_data);
3392 	if (rc == 0 || rc == 2) {
3393 		return diag_data.vrdcvfla & 0x80;
3394 	} else {
3395 		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
3396 			  dev_id.devno, rc);
3397 		return 0;
3398 	}
3399 }
3400 EXPORT_SYMBOL_GPL(dasd_device_is_ro);
3401 
dasd_generic_auto_online(void * data,async_cookie_t cookie)3402 static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
3403 {
3404 	struct ccw_device *cdev = data;
3405 	int ret;
3406 
3407 	ret = ccw_device_set_online(cdev);
3408 	if (ret)
3409 		pr_warn("%s: Setting the DASD online failed with rc=%d\n",
3410 			dev_name(&cdev->dev), ret);
3411 }
3412 
3413 /*
3414  * Initial attempt at a probe function. this can be simplified once
3415  * the other detection code is gone.
3416  */
dasd_generic_probe(struct ccw_device * cdev)3417 int dasd_generic_probe(struct ccw_device *cdev)
3418 {
3419 	cdev->handler = &dasd_int_handler;
3420 
3421 	/*
3422 	 * Automatically online either all dasd devices (dasd_autodetect)
3423 	 * or all devices specified with dasd= parameters during
3424 	 * initial probe.
3425 	 */
3426 	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3427 	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3428 		async_schedule(dasd_generic_auto_online, cdev);
3429 	return 0;
3430 }
3431 EXPORT_SYMBOL_GPL(dasd_generic_probe);
3432 
dasd_generic_free_discipline(struct dasd_device * device)3433 void dasd_generic_free_discipline(struct dasd_device *device)
3434 {
3435 	/* Forget the discipline information. */
3436 	if (device->discipline) {
3437 		if (device->discipline->uncheck_device)
3438 			device->discipline->uncheck_device(device);
3439 		module_put(device->discipline->owner);
3440 		device->discipline = NULL;
3441 	}
3442 	if (device->base_discipline) {
3443 		module_put(device->base_discipline->owner);
3444 		device->base_discipline = NULL;
3445 	}
3446 }
3447 EXPORT_SYMBOL_GPL(dasd_generic_free_discipline);
3448 
3449 /*
3450  * This will one day be called from a global not_oper handler.
3451  * It is also used by driver_unregister during module unload.
3452  */
dasd_generic_remove(struct ccw_device * cdev)3453 void dasd_generic_remove(struct ccw_device *cdev)
3454 {
3455 	struct dasd_device *device;
3456 	struct dasd_block *block;
3457 
3458 	device = dasd_device_from_cdev(cdev);
3459 	if (IS_ERR(device))
3460 		return;
3461 
3462 	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags) &&
3463 	    !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3464 		/* Already doing offline processing */
3465 		dasd_put_device(device);
3466 		return;
3467 	}
3468 	/*
3469 	 * This device is removed unconditionally. Set offline
3470 	 * flag to prevent dasd_open from opening it while it is
3471 	 * no quite down yet.
3472 	 */
3473 	dasd_set_target_state(device, DASD_STATE_NEW);
3474 	cdev->handler = NULL;
3475 	/* dasd_delete_device destroys the device reference. */
3476 	block = device->block;
3477 	dasd_delete_device(device);
3478 	/*
3479 	 * life cycle of block is bound to device, so delete it after
3480 	 * device was safely removed
3481 	 */
3482 	if (block)
3483 		dasd_free_block(block);
3484 }
3485 EXPORT_SYMBOL_GPL(dasd_generic_remove);
3486 
3487 /*
3488  * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
3489  * the device is detected for the first time and is supposed to be used
3490  * or the user has started activation through sysfs.
3491  */
dasd_generic_set_online(struct ccw_device * cdev,struct dasd_discipline * base_discipline)3492 int dasd_generic_set_online(struct ccw_device *cdev,
3493 			    struct dasd_discipline *base_discipline)
3494 {
3495 	struct dasd_discipline *discipline;
3496 	struct dasd_device *device;
3497 	int rc;
3498 
3499 	/* first online clears initial online feature flag */
3500 	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
3501 	device = dasd_create_device(cdev);
3502 	if (IS_ERR(device))
3503 		return PTR_ERR(device);
3504 
3505 	discipline = base_discipline;
3506 	if (device->features & DASD_FEATURE_USEDIAG) {
3507 	  	if (!dasd_diag_discipline_pointer) {
3508 			/* Try to load the required module. */
3509 			rc = request_module(DASD_DIAG_MOD);
3510 			if (rc) {
3511 				pr_warn("%s Setting the DASD online failed "
3512 					"because the required module %s "
3513 					"could not be loaded (rc=%d)\n",
3514 					dev_name(&cdev->dev), DASD_DIAG_MOD,
3515 					rc);
3516 				dasd_delete_device(device);
3517 				return -ENODEV;
3518 			}
3519 		}
3520 		/* Module init could have failed, so check again here after
3521 		 * request_module(). */
3522 		if (!dasd_diag_discipline_pointer) {
3523 			pr_warn("%s Setting the DASD online failed because of missing DIAG discipline\n",
3524 				dev_name(&cdev->dev));
3525 			dasd_delete_device(device);
3526 			return -ENODEV;
3527 		}
3528 		discipline = dasd_diag_discipline_pointer;
3529 	}
3530 	if (!try_module_get(base_discipline->owner)) {
3531 		dasd_delete_device(device);
3532 		return -EINVAL;
3533 	}
3534 	if (!try_module_get(discipline->owner)) {
3535 		module_put(base_discipline->owner);
3536 		dasd_delete_device(device);
3537 		return -EINVAL;
3538 	}
3539 	device->base_discipline = base_discipline;
3540 	device->discipline = discipline;
3541 
3542 	/* check_device will allocate block device if necessary */
3543 	rc = discipline->check_device(device);
3544 	if (rc) {
3545 		pr_warn("%s Setting the DASD online with discipline %s failed with rc=%i\n",
3546 			dev_name(&cdev->dev), discipline->name, rc);
3547 		module_put(discipline->owner);
3548 		module_put(base_discipline->owner);
3549 		dasd_delete_device(device);
3550 		return rc;
3551 	}
3552 
3553 	dasd_set_target_state(device, DASD_STATE_ONLINE);
3554 	if (device->state <= DASD_STATE_KNOWN) {
3555 		pr_warn("%s Setting the DASD online failed because of a missing discipline\n",
3556 			dev_name(&cdev->dev));
3557 		rc = -ENODEV;
3558 		dasd_set_target_state(device, DASD_STATE_NEW);
3559 		if (device->block)
3560 			dasd_free_block(device->block);
3561 		dasd_delete_device(device);
3562 	} else
3563 		pr_debug("dasd_generic device %s found\n",
3564 				dev_name(&cdev->dev));
3565 
3566 	wait_event(dasd_init_waitq, _wait_for_device(device));
3567 
3568 	dasd_put_device(device);
3569 	return rc;
3570 }
3571 EXPORT_SYMBOL_GPL(dasd_generic_set_online);
3572 
dasd_generic_set_offline(struct ccw_device * cdev)3573 int dasd_generic_set_offline(struct ccw_device *cdev)
3574 {
3575 	struct dasd_device *device;
3576 	struct dasd_block *block;
3577 	int max_count, open_count, rc;
3578 	unsigned long flags;
3579 
3580 	rc = 0;
3581 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3582 	device = dasd_device_from_cdev_locked(cdev);
3583 	if (IS_ERR(device)) {
3584 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3585 		return PTR_ERR(device);
3586 	}
3587 
3588 	/*
3589 	 * We must make sure that this device is currently not in use.
3590 	 * The open_count is increased for every opener, that includes
3591 	 * the blkdev_get in dasd_scan_partitions. We are only interested
3592 	 * in the other openers.
3593 	 */
3594 	if (device->block) {
3595 		max_count = device->block->bdev ? 0 : -1;
3596 		open_count = atomic_read(&device->block->open_count);
3597 		if (open_count > max_count) {
3598 			if (open_count > 0)
3599 				pr_warn("%s: The DASD cannot be set offline with open count %i\n",
3600 					dev_name(&cdev->dev), open_count);
3601 			else
3602 				pr_warn("%s: The DASD cannot be set offline while it is in use\n",
3603 					dev_name(&cdev->dev));
3604 			rc = -EBUSY;
3605 			goto out_err;
3606 		}
3607 	}
3608 
3609 	/*
3610 	 * Test if the offline processing is already running and exit if so.
3611 	 * If a safe offline is being processed this could only be a normal
3612 	 * offline that should be able to overtake the safe offline and
3613 	 * cancel any I/O we do not want to wait for any longer
3614 	 */
3615 	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
3616 		if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3617 			clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING,
3618 				  &device->flags);
3619 		} else {
3620 			rc = -EBUSY;
3621 			goto out_err;
3622 		}
3623 	}
3624 	set_bit(DASD_FLAG_OFFLINE, &device->flags);
3625 
3626 	/*
3627 	 * if safe_offline is called set safe_offline_running flag and
3628 	 * clear safe_offline so that a call to normal offline
3629 	 * can overrun safe_offline processing
3630 	 */
3631 	if (test_and_clear_bit(DASD_FLAG_SAFE_OFFLINE, &device->flags) &&
3632 	    !test_and_set_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3633 		/* need to unlock here to wait for outstanding I/O */
3634 		spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3635 		/*
3636 		 * If we want to set the device safe offline all IO operations
3637 		 * should be finished before continuing the offline process
3638 		 * so sync bdev first and then wait for our queues to become
3639 		 * empty
3640 		 */
3641 		if (device->block)
3642 			bdev_mark_dead(device->block->bdev, false);
3643 		dasd_schedule_device_bh(device);
3644 		rc = wait_event_interruptible(shutdown_waitq,
3645 					      _wait_for_empty_queues(device));
3646 		if (rc != 0)
3647 			goto interrupted;
3648 
3649 		/*
3650 		 * check if a normal offline process overtook the offline
3651 		 * processing in this case simply do nothing beside returning
3652 		 * that we got interrupted
3653 		 * otherwise mark safe offline as not running any longer and
3654 		 * continue with normal offline
3655 		 */
3656 		spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3657 		if (!test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
3658 			rc = -ERESTARTSYS;
3659 			goto out_err;
3660 		}
3661 		clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3662 	}
3663 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3664 
3665 	dasd_set_target_state(device, DASD_STATE_NEW);
3666 	/* dasd_delete_device destroys the device reference. */
3667 	block = device->block;
3668 	dasd_delete_device(device);
3669 	/*
3670 	 * life cycle of block is bound to device, so delete it after
3671 	 * device was safely removed
3672 	 */
3673 	if (block)
3674 		dasd_free_block(block);
3675 
3676 	return 0;
3677 
3678 interrupted:
3679 	/* interrupted by signal */
3680 	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
3681 	clear_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags);
3682 	clear_bit(DASD_FLAG_OFFLINE, &device->flags);
3683 out_err:
3684 	dasd_put_device(device);
3685 	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
3686 	return rc;
3687 }
3688 EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3689 
dasd_generic_last_path_gone(struct dasd_device * device)3690 int dasd_generic_last_path_gone(struct dasd_device *device)
3691 {
3692 	struct dasd_ccw_req *cqr;
3693 
3694 	dev_warn(&device->cdev->dev, "No operational channel path is left "
3695 		 "for the device\n");
3696 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
3697 	/* First call extended error reporting and check for autoquiesce. */
3698 	dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
3699 
3700 	if (device->state < DASD_STATE_BASIC)
3701 		return 0;
3702 	/* Device is active. We want to keep it. */
3703 	list_for_each_entry(cqr, &device->ccw_queue, devlist)
3704 		if ((cqr->status == DASD_CQR_IN_IO) ||
3705 		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
3706 			cqr->status = DASD_CQR_QUEUED;
3707 			cqr->retries++;
3708 		}
3709 	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
3710 	dasd_device_clear_timer(device);
3711 	dasd_schedule_device_bh(device);
3712 	return 1;
3713 }
3714 EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);
3715 
dasd_generic_path_operational(struct dasd_device * device)3716 int dasd_generic_path_operational(struct dasd_device *device)
3717 {
3718 	dev_info(&device->cdev->dev, "A channel path to the device has become "
3719 		 "operational\n");
3720 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
3721 	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
3722 	dasd_schedule_device_bh(device);
3723 	if (device->block) {
3724 		dasd_schedule_block_bh(device->block);
3725 		if (device->block->gdp)
3726 			blk_mq_run_hw_queues(device->block->gdp->queue, true);
3727 	}
3728 
3729 	if (!device->stopped)
3730 		wake_up(&generic_waitq);
3731 
3732 	return 1;
3733 }
3734 EXPORT_SYMBOL_GPL(dasd_generic_path_operational);
3735 
dasd_generic_notify(struct ccw_device * cdev,int event)3736 int dasd_generic_notify(struct ccw_device *cdev, int event)
3737 {
3738 	struct dasd_device *device;
3739 	int ret;
3740 
3741 	device = dasd_device_from_cdev_locked(cdev);
3742 	if (IS_ERR(device))
3743 		return 0;
3744 	ret = 0;
3745 	switch (event) {
3746 	case CIO_GONE:
3747 	case CIO_BOXED:
3748 	case CIO_NO_PATH:
3749 		dasd_path_no_path(device);
3750 		ret = dasd_generic_last_path_gone(device);
3751 		break;
3752 	case CIO_OPER:
3753 		ret = 1;
3754 		if (dasd_path_get_opm(device))
3755 			ret = dasd_generic_path_operational(device);
3756 		break;
3757 	}
3758 	dasd_put_device(device);
3759 	return ret;
3760 }
3761 EXPORT_SYMBOL_GPL(dasd_generic_notify);
3762 
dasd_generic_path_event(struct ccw_device * cdev,int * path_event)3763 void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
3764 {
3765 	struct dasd_device *device;
3766 	int chp, oldopm, hpfpm, ifccpm;
3767 
3768 	device = dasd_device_from_cdev_locked(cdev);
3769 	if (IS_ERR(device))
3770 		return;
3771 
3772 	oldopm = dasd_path_get_opm(device);
3773 	for (chp = 0; chp < 8; chp++) {
3774 		if (path_event[chp] & PE_PATH_GONE) {
3775 			dasd_path_notoper(device, chp);
3776 		}
3777 		if (path_event[chp] & PE_PATH_AVAILABLE) {
3778 			dasd_path_available(device, chp);
3779 			dasd_schedule_device_bh(device);
3780 		}
3781 		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
3782 			if (!dasd_path_is_operational(device, chp) &&
3783 			    !dasd_path_need_verify(device, chp)) {
3784 				/*
3785 				 * we can not establish a pathgroup on an
3786 				 * unavailable path, so trigger a path
3787 				 * verification first
3788 				 */
3789 			dasd_path_available(device, chp);
3790 			dasd_schedule_device_bh(device);
3791 			}
3792 			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
3793 				      "Pathgroup re-established\n");
3794 			if (device->discipline->kick_validate)
3795 				device->discipline->kick_validate(device);
3796 		}
3797 		if (path_event[chp] & PE_PATH_FCES_EVENT) {
3798 			dasd_path_fcsec_update(device, chp);
3799 			dasd_schedule_device_bh(device);
3800 		}
3801 	}
3802 	hpfpm = dasd_path_get_hpfpm(device);
3803 	ifccpm = dasd_path_get_ifccpm(device);
3804 	if (!dasd_path_get_opm(device) && hpfpm) {
3805 		/*
3806 		 * device has no operational paths but at least one path is
3807 		 * disabled due to HPF errors
3808 		 * disable HPF at all and use the path(s) again
3809 		 */
3810 		if (device->discipline->disable_hpf)
3811 			device->discipline->disable_hpf(device);
3812 		dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
3813 		dasd_path_set_tbvpm(device, hpfpm);
3814 		dasd_schedule_device_bh(device);
3815 		dasd_schedule_requeue(device);
3816 	} else if (!dasd_path_get_opm(device) && ifccpm) {
3817 		/*
3818 		 * device has no operational paths but at least one path is
3819 		 * disabled due to IFCC errors
3820 		 * trigger path verification on paths with IFCC errors
3821 		 */
3822 		dasd_path_set_tbvpm(device, ifccpm);
3823 		dasd_schedule_device_bh(device);
3824 	}
3825 	if (oldopm && !dasd_path_get_opm(device) && !hpfpm && !ifccpm) {
3826 		dev_warn(&device->cdev->dev,
3827 			 "No verified channel paths remain for the device\n");
3828 		DBF_DEV_EVENT(DBF_WARNING, device,
3829 			      "%s", "last verified path gone");
3830 		/* First call extended error reporting and check for autoquiesce. */
3831 		dasd_handle_autoquiesce(device, NULL, DASD_EER_NOPATH);
3832 		dasd_device_set_stop_bits(device,
3833 					  DASD_STOPPED_DC_WAIT);
3834 	}
3835 	dasd_put_device(device);
3836 }
3837 EXPORT_SYMBOL_GPL(dasd_generic_path_event);
3838 
dasd_generic_verify_path(struct dasd_device * device,__u8 lpm)3839 int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
3840 {
3841 	if (!dasd_path_get_opm(device) && lpm) {
3842 		dasd_path_set_opm(device, lpm);
3843 		dasd_generic_path_operational(device);
3844 	} else
3845 		dasd_path_add_opm(device, lpm);
3846 	return 0;
3847 }
3848 EXPORT_SYMBOL_GPL(dasd_generic_verify_path);
3849 
dasd_generic_space_exhaust(struct dasd_device * device,struct dasd_ccw_req * cqr)3850 void dasd_generic_space_exhaust(struct dasd_device *device,
3851 				struct dasd_ccw_req *cqr)
3852 {
3853 	/* First call extended error reporting and check for autoquiesce. */
3854 	dasd_handle_autoquiesce(device, NULL, DASD_EER_NOSPC);
3855 
3856 	if (device->state < DASD_STATE_BASIC)
3857 		return;
3858 
3859 	if (cqr->status == DASD_CQR_IN_IO ||
3860 	    cqr->status == DASD_CQR_CLEAR_PENDING) {
3861 		cqr->status = DASD_CQR_QUEUED;
3862 		cqr->retries++;
3863 	}
3864 	dasd_device_set_stop_bits(device, DASD_STOPPED_NOSPC);
3865 	dasd_device_clear_timer(device);
3866 	dasd_schedule_device_bh(device);
3867 }
3868 EXPORT_SYMBOL_GPL(dasd_generic_space_exhaust);
3869 
dasd_generic_space_avail(struct dasd_device * device)3870 void dasd_generic_space_avail(struct dasd_device *device)
3871 {
3872 	dev_info(&device->cdev->dev, "Extent pool space is available\n");
3873 	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "space available");
3874 
3875 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOSPC);
3876 	dasd_schedule_device_bh(device);
3877 
3878 	if (device->block) {
3879 		dasd_schedule_block_bh(device->block);
3880 		if (device->block->gdp)
3881 			blk_mq_run_hw_queues(device->block->gdp->queue, true);
3882 	}
3883 	if (!device->stopped)
3884 		wake_up(&generic_waitq);
3885 }
3886 EXPORT_SYMBOL_GPL(dasd_generic_space_avail);
3887 
3888 /*
3889  * clear active requests and requeue them to block layer if possible
3890  */
dasd_generic_requeue_all_requests(struct dasd_device * device)3891 int dasd_generic_requeue_all_requests(struct dasd_device *device)
3892 {
3893 	struct dasd_block *block = device->block;
3894 	struct list_head requeue_queue;
3895 	struct dasd_ccw_req *cqr, *n;
3896 	int rc;
3897 
3898 	if (!block)
3899 		return 0;
3900 
3901 	INIT_LIST_HEAD(&requeue_queue);
3902 	rc = _dasd_requests_to_flushqueue(block, &requeue_queue);
3903 
3904 	/* Now call the callback function of flushed requests */
3905 restart_cb:
3906 	list_for_each_entry_safe(cqr, n, &requeue_queue, blocklist) {
3907 		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
3908 		/* Process finished ERP request. */
3909 		if (cqr->refers) {
3910 			spin_lock_bh(&block->queue_lock);
3911 			__dasd_process_erp(block->base, cqr);
3912 			spin_unlock_bh(&block->queue_lock);
3913 			/* restart list_for_xx loop since dasd_process_erp
3914 			 * might remove multiple elements
3915 			 */
3916 			goto restart_cb;
3917 		}
3918 		_dasd_requeue_request(cqr);
3919 		list_del_init(&cqr->blocklist);
3920 		cqr->block->base->discipline->free_cp(
3921 			cqr, (struct request *) cqr->callback_data);
3922 	}
3923 	dasd_schedule_device_bh(device);
3924 	return rc;
3925 }
3926 EXPORT_SYMBOL_GPL(dasd_generic_requeue_all_requests);
3927 
do_requeue_requests(struct work_struct * work)3928 static void do_requeue_requests(struct work_struct *work)
3929 {
3930 	struct dasd_device *device = container_of(work, struct dasd_device,
3931 						  requeue_requests);
3932 	dasd_generic_requeue_all_requests(device);
3933 	dasd_device_remove_stop_bits(device, DASD_STOPPED_NOT_ACC);
3934 	if (device->block)
3935 		dasd_schedule_block_bh(device->block);
3936 	dasd_put_device(device);
3937 }
3938 
dasd_schedule_requeue(struct dasd_device * device)3939 void dasd_schedule_requeue(struct dasd_device *device)
3940 {
3941 	dasd_get_device(device);
3942 	/* queue call to dasd_reload_device to the kernel event daemon. */
3943 	if (!schedule_work(&device->requeue_requests))
3944 		dasd_put_device(device);
3945 }
3946 EXPORT_SYMBOL(dasd_schedule_requeue);
3947 
dasd_handle_autoquiesce(struct dasd_device * device,struct dasd_ccw_req * cqr,unsigned int reason)3948 static int dasd_handle_autoquiesce(struct dasd_device *device,
3949 				   struct dasd_ccw_req *cqr,
3950 				   unsigned int reason)
3951 {
3952 	/* in any case write eer message with reason */
3953 	if (dasd_eer_enabled(device))
3954 		dasd_eer_write(device, cqr, reason);
3955 
3956 	if (!test_bit(reason, &device->aq_mask))
3957 		return 0;
3958 
3959 	/* notify eer about autoquiesce */
3960 	if (dasd_eer_enabled(device))
3961 		dasd_eer_write(device, NULL, DASD_EER_AUTOQUIESCE);
3962 
3963 	pr_info("%s: The DASD has been put in the quiesce state\n",
3964 		dev_name(&device->cdev->dev));
3965 	dasd_device_set_stop_bits(device, DASD_STOPPED_QUIESCE);
3966 
3967 	if (device->features & DASD_FEATURE_REQUEUEQUIESCE)
3968 		dasd_schedule_requeue(device);
3969 
3970 	return 1;
3971 }
3972 
dasd_generic_build_rdc(struct dasd_device * device,int rdc_buffer_size,int magic)3973 static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
3974 						   int rdc_buffer_size,
3975 						   int magic)
3976 {
3977 	struct dasd_ccw_req *cqr;
3978 	struct ccw1 *ccw;
3979 
3980 	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device,
3981 				   NULL);
3982 
3983 	if (IS_ERR(cqr)) {
3984 		/* internal error 13 - Allocating the RDC request failed*/
3985 		dev_err(&device->cdev->dev,
3986 			 "An error occurred in the DASD device driver, "
3987 			 "reason=%s\n", "13");
3988 		return cqr;
3989 	}
3990 
3991 	ccw = cqr->cpaddr;
3992 	ccw->cmd_code = CCW_CMD_RDC;
3993 	ccw->cda = (__u32)virt_to_phys(cqr->data);
3994 	ccw->flags = 0;
3995 	ccw->count = rdc_buffer_size;
3996 	cqr->startdev = device;
3997 	cqr->memdev = device;
3998 	cqr->expires = 10*HZ;
3999 	cqr->retries = 256;
4000 	cqr->buildclk = get_tod_clock();
4001 	cqr->status = DASD_CQR_FILLED;
4002 	return cqr;
4003 }
4004 
4005 
dasd_generic_read_dev_chars(struct dasd_device * device,int magic,void * rdc_buffer,int rdc_buffer_size)4006 int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
4007 				void *rdc_buffer, int rdc_buffer_size)
4008 {
4009 	int ret;
4010 	struct dasd_ccw_req *cqr;
4011 
4012 	cqr = dasd_generic_build_rdc(device, rdc_buffer_size, magic);
4013 	if (IS_ERR(cqr))
4014 		return PTR_ERR(cqr);
4015 
4016 	ret = dasd_sleep_on(cqr);
4017 	if (ret == 0)
4018 		memcpy(rdc_buffer, cqr->data, rdc_buffer_size);
4019 	dasd_sfree_request(cqr, cqr->memdev);
4020 	return ret;
4021 }
4022 EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
4023 
4024 /*
4025  *   In command mode and transport mode we need to look for sense
4026  *   data in different places. The sense data itself is allways
4027  *   an array of 32 bytes, so we can unify the sense data access
4028  *   for both modes.
4029  */
dasd_get_sense(struct irb * irb)4030 char *dasd_get_sense(struct irb *irb)
4031 {
4032 	struct tsb *tsb = NULL;
4033 	char *sense = NULL;
4034 
4035 	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
4036 		if (irb->scsw.tm.tcw)
4037 			tsb = tcw_get_tsb(phys_to_virt(irb->scsw.tm.tcw));
4038 		if (tsb && tsb->length == 64 && tsb->flags)
4039 			switch (tsb->flags & 0x07) {
4040 			case 1:	/* tsa_iostat */
4041 				sense = tsb->tsa.iostat.sense;
4042 				break;
4043 			case 2: /* tsa_ddpc */
4044 				sense = tsb->tsa.ddpc.sense;
4045 				break;
4046 			default:
4047 				/* currently we don't use interrogate data */
4048 				break;
4049 			}
4050 	} else if (irb->esw.esw0.erw.cons) {
4051 		sense = irb->ecw;
4052 	}
4053 	return sense;
4054 }
4055 EXPORT_SYMBOL_GPL(dasd_get_sense);
4056 
dasd_generic_shutdown(struct ccw_device * cdev)4057 void dasd_generic_shutdown(struct ccw_device *cdev)
4058 {
4059 	struct dasd_device *device;
4060 
4061 	device = dasd_device_from_cdev(cdev);
4062 	if (IS_ERR(device))
4063 		return;
4064 
4065 	if (device->block)
4066 		dasd_schedule_block_bh(device->block);
4067 
4068 	dasd_schedule_device_bh(device);
4069 
4070 	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
4071 }
4072 EXPORT_SYMBOL_GPL(dasd_generic_shutdown);
4073 
dasd_init(void)4074 static int __init dasd_init(void)
4075 {
4076 	int rc;
4077 
4078 	init_waitqueue_head(&dasd_init_waitq);
4079 	init_waitqueue_head(&dasd_flush_wq);
4080 	init_waitqueue_head(&generic_waitq);
4081 	init_waitqueue_head(&shutdown_waitq);
4082 
4083 	/* register 'common' DASD debug area, used for all DBF_XXX calls */
4084 	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
4085 	if (dasd_debug_area == NULL) {
4086 		rc = -ENOMEM;
4087 		goto failed;
4088 	}
4089 	debug_register_view(dasd_debug_area, &debug_sprintf_view);
4090 	debug_set_level(dasd_debug_area, DBF_WARNING);
4091 
4092 	DBF_EVENT(DBF_EMERG, "%s", "debug area created");
4093 
4094 	dasd_diag_discipline_pointer = NULL;
4095 
4096 	dasd_statistics_createroot();
4097 
4098 	rc = dasd_devmap_init();
4099 	if (rc)
4100 		goto failed;
4101 	rc = dasd_gendisk_init();
4102 	if (rc)
4103 		goto failed;
4104 	rc = dasd_parse();
4105 	if (rc)
4106 		goto failed;
4107 	rc = dasd_eer_init();
4108 	if (rc)
4109 		goto failed;
4110 #ifdef CONFIG_PROC_FS
4111 	rc = dasd_proc_init();
4112 	if (rc)
4113 		goto failed;
4114 #endif
4115 
4116 	return 0;
4117 failed:
4118 	pr_info("The DASD device driver could not be initialized\n");
4119 	dasd_exit();
4120 	return rc;
4121 }
4122 
4123 module_init(dasd_init);
4124 module_exit(dasd_exit);
4125