Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
[muen/linux.git] / drivers / s390 / block / dasd.c
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_SUPPORTED_DEVICE("dasd");
58 MODULE_LICENSE("GPL");
59
60 /*
61  * SECTION: prototypes for static functions of dasd.c
62  */
63 static int  dasd_alloc_queue(struct dasd_block *);
64 static void dasd_setup_queue(struct dasd_block *);
65 static void dasd_free_queue(struct dasd_block *);
66 static int dasd_flush_block_queue(struct dasd_block *);
67 static void dasd_device_tasklet(struct dasd_device *);
68 static void dasd_block_tasklet(struct dasd_block *);
69 static void do_kick_device(struct work_struct *);
70 static void do_restore_device(struct work_struct *);
71 static void do_reload_device(struct work_struct *);
72 static void do_requeue_requests(struct work_struct *);
73 static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
74 static void dasd_device_timeout(struct timer_list *);
75 static void dasd_block_timeout(struct timer_list *);
76 static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
77 static void dasd_profile_init(struct dasd_profile *, struct dentry *);
78 static void dasd_profile_exit(struct dasd_profile *);
79 static void dasd_hosts_init(struct dentry *, struct dasd_device *);
80 static void dasd_hosts_exit(struct dasd_device *);
81
82 /*
83  * SECTION: Operations on the device structure.
84  */
85 static wait_queue_head_t dasd_init_waitq;
86 static wait_queue_head_t dasd_flush_wq;
87 static wait_queue_head_t generic_waitq;
88 static wait_queue_head_t shutdown_waitq;
89
90 /*
91  * Allocate memory for a new device structure.
92  */
93 struct dasd_device *dasd_alloc_device(void)
94 {
95         struct dasd_device *device;
96
97         device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
98         if (!device)
99                 return ERR_PTR(-ENOMEM);
100
101         /* Get two pages for normal block device operations. */
102         device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
103         if (!device->ccw_mem) {
104                 kfree(device);
105                 return ERR_PTR(-ENOMEM);
106         }
107         /* Get one page for error recovery. */
108         device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
109         if (!device->erp_mem) {
110                 free_pages((unsigned long) device->ccw_mem, 1);
111                 kfree(device);
112                 return ERR_PTR(-ENOMEM);
113         }
114
115         dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
116         dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
117         spin_lock_init(&device->mem_lock);
118         atomic_set(&device->tasklet_scheduled, 0);
119         tasklet_init(&device->tasklet,
120                      (void (*)(unsigned long)) dasd_device_tasklet,
121                      (unsigned long) device);
122         INIT_LIST_HEAD(&device->ccw_queue);
123         timer_setup(&device->timer, dasd_device_timeout, 0);
124         INIT_WORK(&device->kick_work, do_kick_device);
125         INIT_WORK(&device->restore_device, do_restore_device);
126         INIT_WORK(&device->reload_device, do_reload_device);
127         INIT_WORK(&device->requeue_requests, do_requeue_requests);
128         device->state = DASD_STATE_NEW;
129         device->target = DASD_STATE_NEW;
130         mutex_init(&device->state_mutex);
131         spin_lock_init(&device->profile.lock);
132         return device;
133 }
134
135 /*
136  * Free memory of a device structure.
137  */
138 void dasd_free_device(struct dasd_device *device)
139 {
140         kfree(device->private);
141         free_page((unsigned long) device->erp_mem);
142         free_pages((unsigned long) device->ccw_mem, 1);
143         kfree(device);
144 }
145
146 /*
147  * Allocate memory for a new device structure.
148  */
149 struct dasd_block *dasd_alloc_block(void)
150 {
151         struct dasd_block *block;
152
153         block = kzalloc(sizeof(*block), GFP_ATOMIC);
154         if (!block)
155                 return ERR_PTR(-ENOMEM);
156         /* open_count = 0 means device online but not in use */
157         atomic_set(&block->open_count, -1);
158
159         atomic_set(&block->tasklet_scheduled, 0);
160         tasklet_init(&block->tasklet,
161                      (void (*)(unsigned long)) dasd_block_tasklet,
162                      (unsigned long) block);
163         INIT_LIST_HEAD(&block->ccw_queue);
164         spin_lock_init(&block->queue_lock);
165         timer_setup(&block->timer, dasd_block_timeout, 0);
166         spin_lock_init(&block->profile.lock);
167
168         return block;
169 }
170 EXPORT_SYMBOL_GPL(dasd_alloc_block);
171
172 /*
173  * Free memory of a device structure.
174  */
175 void dasd_free_block(struct dasd_block *block)
176 {
177         kfree(block);
178 }
179 EXPORT_SYMBOL_GPL(dasd_free_block);
180
181 /*
182  * Make a new device known to the system.
183  */
184 static int dasd_state_new_to_known(struct dasd_device *device)
185 {
186         int rc;
187
188         /*
189          * As long as the device is not in state DASD_STATE_NEW we want to
190          * keep the reference count > 0.
191          */
192         dasd_get_device(device);
193
194         if (device->block) {
195                 rc = dasd_alloc_queue(device->block);
196                 if (rc) {
197                         dasd_put_device(device);
198                         return rc;
199                 }
200         }
201         device->state = DASD_STATE_KNOWN;
202         return 0;
203 }
204
205 /*
206  * Let the system forget about a device.
207  */
208 static int dasd_state_known_to_new(struct dasd_device *device)
209 {
210         /* Disable extended error reporting for this device. */
211         dasd_eer_disable(device);
212         device->state = DASD_STATE_NEW;
213
214         if (device->block)
215                 dasd_free_queue(device->block);
216
217         /* Give up reference we took in dasd_state_new_to_known. */
218         dasd_put_device(device);
219         return 0;
220 }
221
222 static struct dentry *dasd_debugfs_setup(const char *name,
223                                          struct dentry *base_dentry)
224 {
225         struct dentry *pde;
226
227         if (!base_dentry)
228                 return NULL;
229         pde = debugfs_create_dir(name, base_dentry);
230         if (!pde || IS_ERR(pde))
231                 return NULL;
232         return pde;
233 }
234
235 /*
236  * Request the irq line for the device.
237  */
238 static int dasd_state_known_to_basic(struct dasd_device *device)
239 {
240         struct dasd_block *block = device->block;
241         int rc = 0;
242
243         /* Allocate and register gendisk structure. */
244         if (block) {
245                 rc = dasd_gendisk_alloc(block);
246                 if (rc)
247                         return rc;
248                 block->debugfs_dentry =
249                         dasd_debugfs_setup(block->gdp->disk_name,
250                                            dasd_debugfs_root_entry);
251                 dasd_profile_init(&block->profile, block->debugfs_dentry);
252                 if (dasd_global_profile_level == DASD_PROFILE_ON)
253                         dasd_profile_on(&device->block->profile);
254         }
255         device->debugfs_dentry =
256                 dasd_debugfs_setup(dev_name(&device->cdev->dev),
257                                    dasd_debugfs_root_entry);
258         dasd_profile_init(&device->profile, device->debugfs_dentry);
259         dasd_hosts_init(device->debugfs_dentry, device);
260
261         /* register 'device' debug area, used for all DBF_DEV_XXX calls */
262         device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
263                                             8 * sizeof(long));
264         debug_register_view(device->debug_area, &debug_sprintf_view);
265         debug_set_level(device->debug_area, DBF_WARNING);
266         DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
267
268         device->state = DASD_STATE_BASIC;
269
270         return rc;
271 }
272
273 /*
274  * Release the irq line for the device. Terminate any running i/o.
275  */
276 static int dasd_state_basic_to_known(struct dasd_device *device)
277 {
278         int rc;
279
280         if (device->discipline->basic_to_known) {
281                 rc = device->discipline->basic_to_known(device);
282                 if (rc)
283                         return rc;
284         }
285
286         if (device->block) {
287                 dasd_profile_exit(&device->block->profile);
288                 debugfs_remove(device->block->debugfs_dentry);
289                 dasd_gendisk_free(device->block);
290                 dasd_block_clear_timer(device->block);
291         }
292         rc = dasd_flush_device_queue(device);
293         if (rc)
294                 return rc;
295         dasd_device_clear_timer(device);
296         dasd_profile_exit(&device->profile);
297         dasd_hosts_exit(device);
298         debugfs_remove(device->debugfs_dentry);
299         DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
300         if (device->debug_area != NULL) {
301                 debug_unregister(device->debug_area);
302                 device->debug_area = NULL;
303         }
304         device->state = DASD_STATE_KNOWN;
305         return 0;
306 }
307
308 /*
309  * Do the initial analysis. The do_analysis function may return
310  * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
311  * until the discipline decides to continue the startup sequence
312  * by calling the function dasd_change_state. The eckd disciplines
313  * uses this to start a ccw that detects the format. The completion
314  * interrupt for this detection ccw uses the kernel event daemon to
315  * trigger the call to dasd_change_state. All this is done in the
316  * discipline code, see dasd_eckd.c.
317  * After the analysis ccw is done (do_analysis returned 0) the block
318  * device is setup.
319  * In case the analysis returns an error, the device setup is stopped
320  * (a fake disk was already added to allow formatting).
321  */
322 static int dasd_state_basic_to_ready(struct dasd_device *device)
323 {
324         int rc;
325         struct dasd_block *block;
326         struct gendisk *disk;
327
328         rc = 0;
329         block = device->block;
330         /* make disk known with correct capacity */
331         if (block) {
332                 if (block->base->discipline->do_analysis != NULL)
333                         rc = block->base->discipline->do_analysis(block);
334                 if (rc) {
335                         if (rc != -EAGAIN) {
336                                 device->state = DASD_STATE_UNFMT;
337                                 disk = device->block->gdp;
338                                 kobject_uevent(&disk_to_dev(disk)->kobj,
339                                                KOBJ_CHANGE);
340                                 goto out;
341                         }
342                         return rc;
343                 }
344                 dasd_setup_queue(block);
345                 set_capacity(block->gdp,
346                              block->blocks << block->s2b_shift);
347                 device->state = DASD_STATE_READY;
348                 rc = dasd_scan_partitions(block);
349                 if (rc) {
350                         device->state = DASD_STATE_BASIC;
351                         return rc;
352                 }
353         } else {
354                 device->state = DASD_STATE_READY;
355         }
356 out:
357         if (device->discipline->basic_to_ready)
358                 rc = device->discipline->basic_to_ready(device);
359         return rc;
360 }
361
362 static inline
363 int _wait_for_empty_queues(struct dasd_device *device)
364 {
365         if (device->block)
366                 return list_empty(&device->ccw_queue) &&
367                         list_empty(&device->block->ccw_queue);
368         else
369                 return list_empty(&device->ccw_queue);
370 }
371
372 /*
373  * Remove device from block device layer. Destroy dirty buffers.
374  * Forget format information. Check if the target level is basic
375  * and if it is create fake disk for formatting.
376  */
377 static int dasd_state_ready_to_basic(struct dasd_device *device)
378 {
379         int rc;
380
381         device->state = DASD_STATE_BASIC;
382         if (device->block) {
383                 struct dasd_block *block = device->block;
384                 rc = dasd_flush_block_queue(block);
385                 if (rc) {
386                         device->state = DASD_STATE_READY;
387                         return rc;
388                 }
389                 dasd_destroy_partitions(block);
390                 block->blocks = 0;
391                 block->bp_block = 0;
392                 block->s2b_shift = 0;
393         }
394         return 0;
395 }
396
397 /*
398  * Back to basic.
399  */
400 static int dasd_state_unfmt_to_basic(struct dasd_device *device)
401 {
402         device->state = DASD_STATE_BASIC;
403         return 0;
404 }
405
406 /*
407  * Make the device online and schedule the bottom half to start
408  * the requeueing of requests from the linux request queue to the
409  * ccw queue.
410  */
411 static int
412 dasd_state_ready_to_online(struct dasd_device * device)
413 {
414         struct gendisk *disk;
415         struct disk_part_iter piter;
416         struct hd_struct *part;
417
418         device->state = DASD_STATE_ONLINE;
419         if (device->block) {
420                 dasd_schedule_block_bh(device->block);
421                 if ((device->features & DASD_FEATURE_USERAW)) {
422                         disk = device->block->gdp;
423                         kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
424                         return 0;
425                 }
426                 disk = device->block->bdev->bd_disk;
427                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
428                 while ((part = disk_part_iter_next(&piter)))
429                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
430                 disk_part_iter_exit(&piter);
431         }
432         return 0;
433 }
434
435 /*
436  * Stop the requeueing of requests again.
437  */
438 static int dasd_state_online_to_ready(struct dasd_device *device)
439 {
440         int rc;
441         struct gendisk *disk;
442         struct disk_part_iter piter;
443         struct hd_struct *part;
444
445         if (device->discipline->online_to_ready) {
446                 rc = device->discipline->online_to_ready(device);
447                 if (rc)
448                         return rc;
449         }
450
451         device->state = DASD_STATE_READY;
452         if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
453                 disk = device->block->bdev->bd_disk;
454                 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
455                 while ((part = disk_part_iter_next(&piter)))
456                         kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
457                 disk_part_iter_exit(&piter);
458         }
459         return 0;
460 }
461
462 /*
463  * Device startup state changes.
464  */
465 static int dasd_increase_state(struct dasd_device *device)
466 {
467         int rc;
468
469         rc = 0;
470         if (device->state == DASD_STATE_NEW &&
471             device->target >= DASD_STATE_KNOWN)
472                 rc = dasd_state_new_to_known(device);
473
474         if (!rc &&
475             device->state == DASD_STATE_KNOWN &&
476             device->target >= DASD_STATE_BASIC)
477                 rc = dasd_state_known_to_basic(device);
478
479         if (!rc &&
480             device->state == DASD_STATE_BASIC &&
481             device->target >= DASD_STATE_READY)
482                 rc = dasd_state_basic_to_ready(device);
483
484         if (!rc &&
485             device->state == DASD_STATE_UNFMT &&
486             device->target > DASD_STATE_UNFMT)
487                 rc = -EPERM;
488
489         if (!rc &&
490             device->state == DASD_STATE_READY &&
491             device->target >= DASD_STATE_ONLINE)
492                 rc = dasd_state_ready_to_online(device);
493
494         return rc;
495 }
496
497 /*
498  * Device shutdown state changes.
499  */
500 static int dasd_decrease_state(struct dasd_device *device)
501 {
502         int rc;
503
504         rc = 0;
505         if (device->state == DASD_STATE_ONLINE &&
506             device->target <= DASD_STATE_READY)
507                 rc = dasd_state_online_to_ready(device);
508
509         if (!rc &&
510             device->state == DASD_STATE_READY &&
511             device->target <= DASD_STATE_BASIC)
512                 rc = dasd_state_ready_to_basic(device);
513
514         if (!rc &&
515             device->state == DASD_STATE_UNFMT &&
516             device->target <= DASD_STATE_BASIC)
517                 rc = dasd_state_unfmt_to_basic(device);
518
519         if (!rc &&
520             device->state == DASD_STATE_BASIC &&
521             device->target <= DASD_STATE_KNOWN)
522                 rc = dasd_state_basic_to_known(device);
523
524         if (!rc &&
525             device->state == DASD_STATE_KNOWN &&
526             device->target <= DASD_STATE_NEW)
527                 rc = dasd_state_known_to_new(device);
528
529         return rc;
530 }
531
532 /*
533  * This is the main startup/shutdown routine.
534  */
535 static void dasd_change_state(struct dasd_device *device)
536 {
537         int rc;
538
539         if (device->state == device->target)
540                 /* Already where we want to go today... */
541                 return;
542         if (device->state < device->target)
543                 rc = dasd_increase_state(device);
544         else
545                 rc = dasd_decrease_state(device);
546         if (rc == -EAGAIN)
547                 return;
548         if (rc)
549                 device->target = device->state;
550
551         /* let user-space know that the device status changed */
552         kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
553
554         if (device->state == device->target)
555                 wake_up(&dasd_init_waitq);
556 }
557
558 /*
559  * Kick starter for devices that did not complete the startup/shutdown
560  * procedure or were sleeping because of a pending state.
561  * dasd_kick_device will schedule a call do do_kick_device to the kernel
562  * event daemon.
563  */
564 static void do_kick_device(struct work_struct *work)
565 {
566         struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
567         mutex_lock(&device->state_mutex);
568         dasd_change_state(device);
569         mutex_unlock(&device->state_mutex);
570         dasd_schedule_device_bh(device);
571         dasd_put_device(device);
572 }
573
574 void dasd_kick_device(struct dasd_device *device)
575 {
576         dasd_get_device(device);
577         /* queue call to dasd_kick_device to the kernel event daemon. */
578         if (!schedule_work(&device->kick_work))
579                 dasd_put_device(device);
580 }
581 EXPORT_SYMBOL(dasd_kick_device);
582
583 /*
584  * dasd_reload_device will schedule a call do do_reload_device to the kernel
585  * event daemon.
586  */
587 static void do_reload_device(struct work_struct *work)
588 {
589         struct dasd_device *device = container_of(work, struct dasd_device,
590                                                   reload_device);
591         device->discipline->reload(device);
592         dasd_put_device(device);
593 }
594
595 void dasd_reload_device(struct dasd_device *device)
596 {
597         dasd_get_device(device);
598         /* queue call to dasd_reload_device to the kernel event daemon. */
599         if (!schedule_work(&device->reload_device))
600                 dasd_put_device(device);
601 }
602 EXPORT_SYMBOL(dasd_reload_device);
603
604 /*
605  * dasd_restore_device will schedule a call do do_restore_device to the kernel
606  * event daemon.
607  */
608 static void do_restore_device(struct work_struct *work)
609 {
610         struct dasd_device *device = container_of(work, struct dasd_device,
611                                                   restore_device);
612         device->cdev->drv->restore(device->cdev);
613         dasd_put_device(device);
614 }
615
616 void dasd_restore_device(struct dasd_device *device)
617 {
618         dasd_get_device(device);
619         /* queue call to dasd_restore_device to the kernel event daemon. */
620         if (!schedule_work(&device->restore_device))
621                 dasd_put_device(device);
622 }
623
624 /*
625  * Set the target state for a device and starts the state change.
626  */
627 void dasd_set_target_state(struct dasd_device *device, int target)
628 {
629         dasd_get_device(device);
630         mutex_lock(&device->state_mutex);
631         /* If we are in probeonly mode stop at DASD_STATE_READY. */
632         if (dasd_probeonly && target > DASD_STATE_READY)
633                 target = DASD_STATE_READY;
634         if (device->target != target) {
635                 if (device->state == target)
636                         wake_up(&dasd_init_waitq);
637                 device->target = target;
638         }
639         if (device->state != device->target)
640                 dasd_change_state(device);
641         mutex_unlock(&device->state_mutex);
642         dasd_put_device(device);
643 }
644 EXPORT_SYMBOL(dasd_set_target_state);
645
646 /*
647  * Enable devices with device numbers in [from..to].
648  */
649 static inline int _wait_for_device(struct dasd_device *device)
650 {
651         return (device->state == device->target);
652 }
653
654 void dasd_enable_device(struct dasd_device *device)
655 {
656         dasd_set_target_state(device, DASD_STATE_ONLINE);
657         if (device->state <= DASD_STATE_KNOWN)
658                 /* No discipline for device found. */
659                 dasd_set_target_state(device, DASD_STATE_NEW);
660         /* Now wait for the devices to come up. */
661         wait_event(dasd_init_waitq, _wait_for_device(device));
662
663         dasd_reload_device(device);
664         if (device->discipline->kick_validate)
665                 device->discipline->kick_validate(device);
666 }
667 EXPORT_SYMBOL(dasd_enable_device);
668
669 /*
670  * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
671  */
672
673 unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
674
675 #ifdef CONFIG_DASD_PROFILE
676 struct dasd_profile dasd_global_profile = {
677         .lock = __SPIN_LOCK_UNLOCKED(dasd_global_profile.lock),
678 };
679 static struct dentry *dasd_debugfs_global_entry;
680
681 /*
682  * Add profiling information for cqr before execution.
683  */
684 static void dasd_profile_start(struct dasd_block *block,
685                                struct dasd_ccw_req *cqr,
686                                struct request *req)
687 {
688         struct list_head *l;
689         unsigned int counter;
690         struct dasd_device *device;
691
692         /* count the length of the chanq for statistics */
693         counter = 0;
694         if (dasd_global_profile_level || block->profile.data)
695                 list_for_each(l, &block->ccw_queue)
696                         if (++counter >= 31)
697                                 break;
698
699         spin_lock(&dasd_global_profile.lock);
700         if (dasd_global_profile.data) {
701                 dasd_global_profile.data->dasd_io_nr_req[counter]++;
702                 if (rq_data_dir(req) == READ)
703                         dasd_global_profile.data->dasd_read_nr_req[counter]++;
704         }
705         spin_unlock(&dasd_global_profile.lock);
706
707         spin_lock(&block->profile.lock);
708         if (block->profile.data) {
709                 block->profile.data->dasd_io_nr_req[counter]++;
710                 if (rq_data_dir(req) == READ)
711                         block->profile.data->dasd_read_nr_req[counter]++;
712         }
713         spin_unlock(&block->profile.lock);
714
715         /*
716          * We count the request for the start device, even though it may run on
717          * some other device due to error recovery. This way we make sure that
718          * we count each request only once.
719          */
720         device = cqr->startdev;
721         if (device->profile.data) {
722                 counter = 1; /* request is not yet queued on the start device */
723                 list_for_each(l, &device->ccw_queue)
724                         if (++counter >= 31)
725                                 break;
726         }
727         spin_lock(&device->profile.lock);
728         if (device->profile.data) {
729                 device->profile.data->dasd_io_nr_req[counter]++;
730                 if (rq_data_dir(req) == READ)
731                         device->profile.data->dasd_read_nr_req[counter]++;
732         }
733         spin_unlock(&device->profile.lock);
734 }
735
736 /*
737  * Add profiling information for cqr after execution.
738  */
739
740 #define dasd_profile_counter(value, index)                         \
741 {                                                                  \
742         for (index = 0; index < 31 && value >> (2+index); index++) \
743                 ;                                                  \
744 }
745
746 static void dasd_profile_end_add_data(struct dasd_profile_info *data,
747                                       int is_alias,
748                                       int is_tpm,
749                                       int is_read,
750                                       long sectors,
751                                       int sectors_ind,
752                                       int tottime_ind,
753                                       int tottimeps_ind,
754                                       int strtime_ind,
755                                       int irqtime_ind,
756                                       int irqtimeps_ind,
757                                       int endtime_ind)
758 {
759         /* in case of an overflow, reset the whole profile */
760         if (data->dasd_io_reqs == UINT_MAX) {
761                         memset(data, 0, sizeof(*data));
762                         ktime_get_real_ts64(&data->starttod);
763         }
764         data->dasd_io_reqs++;
765         data->dasd_io_sects += sectors;
766         if (is_alias)
767                 data->dasd_io_alias++;
768         if (is_tpm)
769                 data->dasd_io_tpm++;
770
771         data->dasd_io_secs[sectors_ind]++;
772         data->dasd_io_times[tottime_ind]++;
773         data->dasd_io_timps[tottimeps_ind]++;
774         data->dasd_io_time1[strtime_ind]++;
775         data->dasd_io_time2[irqtime_ind]++;
776         data->dasd_io_time2ps[irqtimeps_ind]++;
777         data->dasd_io_time3[endtime_ind]++;
778
779         if (is_read) {
780                 data->dasd_read_reqs++;
781                 data->dasd_read_sects += sectors;
782                 if (is_alias)
783                         data->dasd_read_alias++;
784                 if (is_tpm)
785                         data->dasd_read_tpm++;
786                 data->dasd_read_secs[sectors_ind]++;
787                 data->dasd_read_times[tottime_ind]++;
788                 data->dasd_read_time1[strtime_ind]++;
789                 data->dasd_read_time2[irqtime_ind]++;
790                 data->dasd_read_time3[endtime_ind]++;
791         }
792 }
793
794 static void dasd_profile_end(struct dasd_block *block,
795                              struct dasd_ccw_req *cqr,
796                              struct request *req)
797 {
798         unsigned long strtime, irqtime, endtime, tottime;
799         unsigned long tottimeps, sectors;
800         struct dasd_device *device;
801         int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
802         int irqtime_ind, irqtimeps_ind, endtime_ind;
803         struct dasd_profile_info *data;
804
805         device = cqr->startdev;
806         if (!(dasd_global_profile_level ||
807               block->profile.data ||
808               device->profile.data))
809                 return;
810
811         sectors = blk_rq_sectors(req);
812         if (!cqr->buildclk || !cqr->startclk ||
813             !cqr->stopclk || !cqr->endclk ||
814             !sectors)
815                 return;
816
817         strtime = ((cqr->startclk - cqr->buildclk) >> 12);
818         irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
819         endtime = ((cqr->endclk - cqr->stopclk) >> 12);
820         tottime = ((cqr->endclk - cqr->buildclk) >> 12);
821         tottimeps = tottime / sectors;
822
823         dasd_profile_counter(sectors, sectors_ind);
824         dasd_profile_counter(tottime, tottime_ind);
825         dasd_profile_counter(tottimeps, tottimeps_ind);
826         dasd_profile_counter(strtime, strtime_ind);
827         dasd_profile_counter(irqtime, irqtime_ind);
828         dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
829         dasd_profile_counter(endtime, endtime_ind);
830
831         spin_lock(&dasd_global_profile.lock);
832         if (dasd_global_profile.data) {
833                 data = dasd_global_profile.data;
834                 data->dasd_sum_times += tottime;
835                 data->dasd_sum_time_str += strtime;
836                 data->dasd_sum_time_irq += irqtime;
837                 data->dasd_sum_time_end += endtime;
838                 dasd_profile_end_add_data(dasd_global_profile.data,
839                                           cqr->startdev != block->base,
840                                           cqr->cpmode == 1,
841                                           rq_data_dir(req) == READ,
842                                           sectors, sectors_ind, tottime_ind,
843                                           tottimeps_ind, strtime_ind,
844                                           irqtime_ind, irqtimeps_ind,
845                                           endtime_ind);
846         }
847         spin_unlock(&dasd_global_profile.lock);
848
849         spin_lock(&block->profile.lock);
850         if (block->profile.data) {
851                 data = block->profile.data;
852                 data->dasd_sum_times += tottime;
853                 data->dasd_sum_time_str += strtime;
854                 data->dasd_sum_time_irq += irqtime;
855                 data->dasd_sum_time_end += endtime;
856                 dasd_profile_end_add_data(block->profile.data,
857                                           cqr->startdev != block->base,
858                                           cqr->cpmode == 1,
859                                           rq_data_dir(req) == READ,
860                                           sectors, sectors_ind, tottime_ind,
861                                           tottimeps_ind, strtime_ind,
862                                           irqtime_ind, irqtimeps_ind,
863                                           endtime_ind);
864         }
865         spin_unlock(&block->profile.lock);
866
867         spin_lock(&device->profile.lock);
868         if (device->profile.data) {
869                 data = device->profile.data;
870                 data->dasd_sum_times += tottime;
871                 data->dasd_sum_time_str += strtime;
872                 data->dasd_sum_time_irq += irqtime;
873                 data->dasd_sum_time_end += endtime;
874                 dasd_profile_end_add_data(device->profile.data,
875                                           cqr->startdev != block->base,
876                                           cqr->cpmode == 1,
877                                           rq_data_dir(req) == READ,
878                                           sectors, sectors_ind, tottime_ind,
879                                           tottimeps_ind, strtime_ind,
880                                           irqtime_ind, irqtimeps_ind,
881                                           endtime_ind);
882         }
883         spin_unlock(&device->profile.lock);
884 }
885
886 void dasd_profile_reset(struct dasd_profile *profile)
887 {
888         struct dasd_profile_info *data;
889
890         spin_lock_bh(&profile->lock);
891         data = profile->data;
892         if (!data) {
893                 spin_unlock_bh(&profile->lock);
894                 return;
895         }
896         memset(data, 0, sizeof(*data));
897         ktime_get_real_ts64(&data->starttod);
898         spin_unlock_bh(&profile->lock);
899 }
900
901 int dasd_profile_on(struct dasd_profile *profile)
902 {
903         struct dasd_profile_info *data;
904
905         data = kzalloc(sizeof(*data), GFP_KERNEL);
906         if (!data)
907                 return -ENOMEM;
908         spin_lock_bh(&profile->lock);
909         if (profile->data) {
910                 spin_unlock_bh(&profile->lock);
911                 kfree(data);
912                 return 0;
913         }
914         ktime_get_real_ts64(&data->starttod);
915         profile->data = data;
916         spin_unlock_bh(&profile->lock);
917         return 0;
918 }
919
920 void dasd_profile_off(struct dasd_profile *profile)
921 {
922         spin_lock_bh(&profile->lock);
923         kfree(profile->data);
924         profile->data = NULL;
925         spin_unlock_bh(&profile->lock);
926 }
927
928 char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
929 {
930         char *buffer;
931
932         buffer = vmalloc(user_len + 1);
933         if (buffer == NULL)
934                 return ERR_PTR(-ENOMEM);
935         if (copy_from_user(buffer, user_buf, user_len) != 0) {
936                 vfree(buffer);
937                 return ERR_PTR(-EFAULT);
938         }
939         /* got the string, now strip linefeed. */
940         if (buffer[user_len - 1] == '\n')
941                 buffer[user_len - 1] = 0;
942         else
943                 buffer[user_len] = 0;
944         return buffer;
945 }
946
947 static ssize_t dasd_stats_write(struct file *file,
948                                 const char __user *user_buf,
949                                 size_t user_len, loff_t *pos)
950 {
951         char *buffer, *str;
952         int rc;
953         struct seq_file *m = (struct seq_file *)file->private_data;
954         struct dasd_profile *prof = m->private;
955
956         if (user_len > 65536)
957                 user_len = 65536;
958         buffer = dasd_get_user_string(user_buf, user_len);
959         if (IS_ERR(buffer))
960                 return PTR_ERR(buffer);
961
962         str = skip_spaces(buffer);
963         rc = user_len;
964         if (strncmp(str, "reset", 5) == 0) {
965                 dasd_profile_reset(prof);
966         } else if (strncmp(str, "on", 2) == 0) {
967                 rc = dasd_profile_on(prof);
968                 if (rc)
969                         goto out;
970                 rc = user_len;
971                 if (prof == &dasd_global_profile) {
972                         dasd_profile_reset(prof);
973                         dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
974                 }
975         } else if (strncmp(str, "off", 3) == 0) {
976                 if (prof == &dasd_global_profile)
977                         dasd_global_profile_level = DASD_PROFILE_OFF;
978                 dasd_profile_off(prof);
979         } else
980                 rc = -EINVAL;
981 out:
982         vfree(buffer);
983         return rc;
984 }
985
986 static void dasd_stats_array(struct seq_file *m, unsigned int *array)
987 {
988         int i;
989
990         for (i = 0; i < 32; i++)
991                 seq_printf(m, "%u ", array[i]);
992         seq_putc(m, '\n');
993 }
994
995 static void dasd_stats_seq_print(struct seq_file *m,
996                                  struct dasd_profile_info *data)
997 {
998         seq_printf(m, "start_time %lld.%09ld\n",
999                    (s64)data->starttod.tv_sec, data->starttod.tv_nsec);
1000         seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
1001         seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
1002         seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
1003         seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
1004         seq_printf(m, "avg_total %lu\n", data->dasd_io_reqs ?
1005                    data->dasd_sum_times / data->dasd_io_reqs : 0UL);
1006         seq_printf(m, "avg_build_to_ssch %lu\n", data->dasd_io_reqs ?
1007                    data->dasd_sum_time_str / data->dasd_io_reqs : 0UL);
1008         seq_printf(m, "avg_ssch_to_irq %lu\n", data->dasd_io_reqs ?
1009                    data->dasd_sum_time_irq / data->dasd_io_reqs : 0UL);
1010         seq_printf(m, "avg_irq_to_end %lu\n", data->dasd_io_reqs ?
1011                    data->dasd_sum_time_end / data->dasd_io_reqs : 0UL);
1012         seq_puts(m, "histogram_sectors ");
1013         dasd_stats_array(m, data->dasd_io_secs);
1014         seq_puts(m, "histogram_io_times ");
1015         dasd_stats_array(m, data->dasd_io_times);
1016         seq_puts(m, "histogram_io_times_weighted ");
1017         dasd_stats_array(m, data->dasd_io_timps);
1018         seq_puts(m, "histogram_time_build_to_ssch ");
1019         dasd_stats_array(m, data->dasd_io_time1);
1020         seq_puts(m, "histogram_time_ssch_to_irq ");
1021         dasd_stats_array(m, data->dasd_io_time2);
1022         seq_puts(m, "histogram_time_ssch_to_irq_weighted ");
1023         dasd_stats_array(m, data->dasd_io_time2ps);
1024         seq_puts(m, "histogram_time_irq_to_end ");
1025         dasd_stats_array(m, data->dasd_io_time3);
1026         seq_puts(m, "histogram_ccw_queue_length ");
1027         dasd_stats_array(m, data->dasd_io_nr_req);
1028         seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
1029         seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
1030         seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
1031         seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
1032         seq_puts(m, "histogram_read_sectors ");
1033         dasd_stats_array(m, data->dasd_read_secs);
1034         seq_puts(m, "histogram_read_times ");
1035         dasd_stats_array(m, data->dasd_read_times);
1036         seq_puts(m, "histogram_read_time_build_to_ssch ");
1037         dasd_stats_array(m, data->dasd_read_time1);
1038         seq_puts(m, "histogram_read_time_ssch_to_irq ");
1039         dasd_stats_array(m, data->dasd_read_time2);
1040         seq_puts(m, "histogram_read_time_irq_to_end ");
1041         dasd_stats_array(m, data->dasd_read_time3);
1042         seq_puts(m, "histogram_read_ccw_queue_length ");
1043         dasd_stats_array(m, data->dasd_read_nr_req);
1044 }
1045
1046 static int dasd_stats_show(struct seq_file *m, void *v)
1047 {
1048         struct dasd_profile *profile;
1049         struct dasd_profile_info *data;
1050
1051         profile = m->private;
1052         spin_lock_bh(&profile->lock);
1053         data = profile->data;
1054         if (!data) {
1055                 spin_unlock_bh(&profile->lock);
1056                 seq_puts(m, "disabled\n");
1057                 return 0;
1058         }
1059         dasd_stats_seq_print(m, data);
1060         spin_unlock_bh(&profile->lock);
1061         return 0;
1062 }
1063
1064 static int dasd_stats_open(struct inode *inode, struct file *file)
1065 {
1066         struct dasd_profile *profile = inode->i_private;
1067         return single_open(file, dasd_stats_show, profile);
1068 }
1069
1070 static const struct file_operations dasd_stats_raw_fops = {
1071         .owner          = THIS_MODULE,
1072         .open           = dasd_stats_open,
1073         .read           = seq_read,
1074         .llseek         = seq_lseek,
1075         .release        = single_release,
1076         .write          = dasd_stats_write,
1077 };
1078
1079 static void dasd_profile_init(struct dasd_profile *profile,
1080                               struct dentry *base_dentry)
1081 {
1082         umode_t mode;
1083         struct dentry *pde;
1084
1085         if (!base_dentry)
1086                 return;
1087         profile->dentry = NULL;
1088         profile->data = NULL;
1089         mode = (S_IRUSR | S_IWUSR | S_IFREG);
1090         pde = debugfs_create_file("statistics", mode, base_dentry,
1091                                   profile, &dasd_stats_raw_fops);
1092         if (pde && !IS_ERR(pde))
1093                 profile->dentry = pde;
1094         return;
1095 }
1096
1097 static void dasd_profile_exit(struct dasd_profile *profile)
1098 {
1099         dasd_profile_off(profile);
1100         debugfs_remove(profile->dentry);
1101         profile->dentry = NULL;
1102 }
1103
1104 static void dasd_statistics_removeroot(void)
1105 {
1106         dasd_global_profile_level = DASD_PROFILE_OFF;
1107         dasd_profile_exit(&dasd_global_profile);
1108         debugfs_remove(dasd_debugfs_global_entry);
1109         debugfs_remove(dasd_debugfs_root_entry);
1110 }
1111
1112 static void dasd_statistics_createroot(void)
1113 {
1114         struct dentry *pde;
1115
1116         dasd_debugfs_root_entry = NULL;
1117         pde = debugfs_create_dir("dasd", NULL);
1118         if (!pde || IS_ERR(pde))
1119                 goto error;
1120         dasd_debugfs_root_entry = pde;
1121         pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
1122         if (!pde || IS_ERR(pde))
1123                 goto error;
1124         dasd_debugfs_global_entry = pde;
1125         dasd_profile_init(&dasd_global_profile, dasd_debugfs_global_entry);
1126         return;
1127
1128 error:
1129         DBF_EVENT(DBF_ERR, "%s",
1130                   "Creation of the dasd debugfs interface failed");
1131         dasd_statistics_removeroot();
1132         return;
1133 }
1134
1135 #else
1136 #define dasd_profile_start(block, cqr, req) do {} while (0)
1137 #define dasd_profile_end(block, cqr, req) do {} while (0)
1138
1139 static void dasd_statistics_createroot(void)
1140 {
1141         return;
1142 }
1143
1144 static void dasd_statistics_removeroot(void)
1145 {
1146         return;
1147 }
1148
1149 int dasd_stats_generic_show(struct seq_file *m, void *v)
1150 {
1151         seq_puts(m, "Statistics are not activated in this kernel\n");
1152         return 0;
1153 }
1154
1155 static void dasd_profile_init(struct dasd_profile *profile,
1156                               struct dentry *base_dentry)
1157 {
1158         return;
1159 }
1160
1161 static void dasd_profile_exit(struct dasd_profile *profile)
1162 {
1163         return;
1164 }
1165
1166 int dasd_profile_on(struct dasd_profile *profile)
1167 {
1168         return 0;
1169 }
1170
1171 #endif                          /* CONFIG_DASD_PROFILE */
1172
1173 static int dasd_hosts_show(struct seq_file *m, void *v)
1174 {
1175         struct dasd_device *device;
1176         int rc = -EOPNOTSUPP;
1177
1178         device = m->private;
1179         dasd_get_device(device);
1180
1181         if (device->discipline->hosts_print)
1182                 rc = device->discipline->hosts_print(device, m);
1183
1184         dasd_put_device(device);
1185         return rc;
1186 }
1187
1188 static int dasd_hosts_open(struct inode *inode, struct file *file)
1189 {
1190         struct dasd_device *device = inode->i_private;
1191
1192         return single_open(file, dasd_hosts_show, device);
1193 }
1194
1195 static const struct file_operations dasd_hosts_fops = {
1196         .owner          = THIS_MODULE,
1197         .open           = dasd_hosts_open,
1198         .read           = seq_read,
1199         .llseek         = seq_lseek,
1200         .release        = single_release,
1201 };
1202
1203 static void dasd_hosts_exit(struct dasd_device *device)
1204 {
1205         debugfs_remove(device->hosts_dentry);
1206         device->hosts_dentry = NULL;
1207 }
1208
1209 static void dasd_hosts_init(struct dentry *base_dentry,
1210                             struct dasd_device *device)
1211 {
1212         struct dentry *pde;
1213         umode_t mode;
1214
1215         if (!base_dentry)
1216                 return;
1217
1218         mode = S_IRUSR | S_IFREG;
1219         pde = debugfs_create_file("host_access_list", mode, base_dentry,
1220                                   device, &dasd_hosts_fops);
1221         if (pde && !IS_ERR(pde))
1222                 device->hosts_dentry = pde;
1223 }
1224
1225 /*
1226  * Allocate memory for a channel program with 'cplength' channel
1227  * command words and 'datasize' additional space. There are two
1228  * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
1229  * memory and 2) dasd_smalloc_request uses the static ccw memory
1230  * that gets allocated for each device.
1231  */
1232 struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1233                                           int datasize,
1234                                           struct dasd_device *device)
1235 {
1236         struct dasd_ccw_req *cqr;
1237
1238         /* Sanity checks */
1239         BUG_ON(datasize > PAGE_SIZE ||
1240              (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
1241
1242         cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
1243         if (cqr == NULL)
1244                 return ERR_PTR(-ENOMEM);
1245         cqr->cpaddr = NULL;
1246         if (cplength > 0) {
1247                 cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
1248                                       GFP_ATOMIC | GFP_DMA);
1249                 if (cqr->cpaddr == NULL) {
1250                         kfree(cqr);
1251                         return ERR_PTR(-ENOMEM);
1252                 }
1253         }
1254         cqr->data = NULL;
1255         if (datasize > 0) {
1256                 cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
1257                 if (cqr->data == NULL) {
1258                         kfree(cqr->cpaddr);
1259                         kfree(cqr);
1260                         return ERR_PTR(-ENOMEM);
1261                 }
1262         }
1263         cqr->magic =  magic;
1264         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1265         dasd_get_device(device);
1266         return cqr;
1267 }
1268 EXPORT_SYMBOL(dasd_kmalloc_request);
1269
1270 struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1271                                           int datasize,
1272                                           struct dasd_device *device)
1273 {
1274         unsigned long flags;
1275         struct dasd_ccw_req *cqr;
1276         char *data;
1277         int size;
1278
1279         size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
1280         if (cplength > 0)
1281                 size += cplength * sizeof(struct ccw1);
1282         if (datasize > 0)
1283                 size += datasize;
1284         spin_lock_irqsave(&device->mem_lock, flags);
1285         cqr = (struct dasd_ccw_req *)
1286                 dasd_alloc_chunk(&device->ccw_chunks, size);
1287         spin_unlock_irqrestore(&device->mem_lock, flags);
1288         if (cqr == NULL)
1289                 return ERR_PTR(-ENOMEM);
1290         memset(cqr, 0, sizeof(struct dasd_ccw_req));
1291         data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
1292         cqr->cpaddr = NULL;
1293         if (cplength > 0) {
1294                 cqr->cpaddr = (struct ccw1 *) data;
1295                 data += cplength*sizeof(struct ccw1);
1296                 memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
1297         }
1298         cqr->data = NULL;
1299         if (datasize > 0) {
1300                 cqr->data = data;
1301                 memset(cqr->data, 0, datasize);
1302         }
1303         cqr->magic = magic;
1304         set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
1305         dasd_get_device(device);
1306         return cqr;
1307 }
1308 EXPORT_SYMBOL(dasd_smalloc_request);
1309
1310 /*
1311  * Free memory of a channel program. This function needs to free all the
1312  * idal lists that might have been created by dasd_set_cda and the
1313  * struct dasd_ccw_req itself.
1314  */
1315 void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1316 {
1317         struct ccw1 *ccw;
1318
1319         /* Clear any idals used for the request. */
1320         ccw = cqr->cpaddr;
1321         do {
1322                 clear_normalized_cda(ccw);
1323         } while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
1324         kfree(cqr->cpaddr);
1325         kfree(cqr->data);
1326         kfree(cqr);
1327         dasd_put_device(device);
1328 }
1329 EXPORT_SYMBOL(dasd_kfree_request);
1330
1331 void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
1332 {
1333         unsigned long flags;
1334
1335         spin_lock_irqsave(&device->mem_lock, flags);
1336         dasd_free_chunk(&device->ccw_chunks, cqr);
1337         spin_unlock_irqrestore(&device->mem_lock, flags);
1338         dasd_put_device(device);
1339 }
1340 EXPORT_SYMBOL(dasd_sfree_request);
1341
1342 /*
1343  * Check discipline magic in cqr.
1344  */
1345 static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
1346 {
1347         struct dasd_device *device;
1348
1349         if (cqr == NULL)
1350                 return -EINVAL;
1351         device = cqr->startdev;
1352         if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
1353                 DBF_DEV_EVENT(DBF_WARNING, device,
1354                             " dasd_ccw_req 0x%08x magic doesn't match"
1355                             " discipline 0x%08x",
1356                             cqr->magic,
1357                             *(unsigned int *) device->discipline->name);
1358                 return -EINVAL;
1359         }
1360         return 0;
1361 }
1362
1363 /*
1364  * Terminate the current i/o and set the request to clear_pending.
1365  * Timer keeps device runnig.
1366  * ccw_device_clear can fail if the i/o subsystem
1367  * is in a bad mood.
1368  */
1369 int dasd_term_IO(struct dasd_ccw_req *cqr)
1370 {
1371         struct dasd_device *device;
1372         int retries, rc;
1373         char errorstring[ERRORLENGTH];
1374
1375         /* Check the cqr */
1376         rc = dasd_check_cqr(cqr);
1377         if (rc)
1378                 return rc;
1379         retries = 0;
1380         device = (struct dasd_device *) cqr->startdev;
1381         while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
1382                 rc = ccw_device_clear(device->cdev, (long) cqr);
1383                 switch (rc) {
1384                 case 0: /* termination successful */
1385                         cqr->status = DASD_CQR_CLEAR_PENDING;
1386                         cqr->stopclk = get_tod_clock();
1387                         cqr->starttime = 0;
1388                         DBF_DEV_EVENT(DBF_DEBUG, device,
1389                                       "terminate cqr %p successful",
1390                                       cqr);
1391                         break;
1392                 case -ENODEV:
1393                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1394                                       "device gone, retry");
1395                         break;
1396                 case -EINVAL:
1397                         /*
1398                          * device not valid so no I/O could be running
1399                          * handle CQR as termination successful
1400                          */
1401                         cqr->status = DASD_CQR_CLEARED;
1402                         cqr->stopclk = get_tod_clock();
1403                         cqr->starttime = 0;
1404                         /* no retries for invalid devices */
1405                         cqr->retries = -1;
1406                         DBF_DEV_EVENT(DBF_ERR, device, "%s",
1407                                       "EINVAL, handle as terminated");
1408                         /* fake rc to success */
1409                         rc = 0;
1410                         break;
1411                 default:
1412                         /* internal error 10 - unknown rc*/
1413                         snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
1414                         dev_err(&device->cdev->dev, "An error occurred in the "
1415                                 "DASD device driver, reason=%s\n", errorstring);
1416                         BUG();
1417                         break;
1418                 }
1419                 retries++;
1420         }
1421         dasd_schedule_device_bh(device);
1422         return rc;
1423 }
1424 EXPORT_SYMBOL(dasd_term_IO);
1425
1426 /*
1427  * Start the i/o. This start_IO can fail if the channel is really busy.
1428  * In that case set up a timer to start the request later.
1429  */
1430 int dasd_start_IO(struct dasd_ccw_req *cqr)
1431 {
1432         struct dasd_device *device;
1433         int rc;
1434         char errorstring[ERRORLENGTH];
1435
1436         /* Check the cqr */
1437         rc = dasd_check_cqr(cqr);
1438         if (rc) {
1439                 cqr->intrc = rc;
1440                 return rc;
1441         }
1442         device = (struct dasd_device *) cqr->startdev;
1443         if (((cqr->block &&
1444               test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
1445              test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
1446             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
1447                 DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
1448                               "because of stolen lock", cqr);
1449                 cqr->status = DASD_CQR_ERROR;
1450                 cqr->intrc = -EPERM;
1451                 return -EPERM;
1452         }
1453         if (cqr->retries < 0) {
1454                 /* internal error 14 - start_IO run out of retries */
1455                 sprintf(errorstring, "14 %p", cqr);
1456                 dev_err(&device->cdev->dev, "An error occurred in the DASD "
1457                         "device driver, reason=%s\n", errorstring);
1458                 cqr->status = DASD_CQR_ERROR;
1459                 return -EIO;
1460         }
1461         cqr->startclk = get_tod_clock();
1462         cqr->starttime = jiffies;
1463         cqr->retries--;
1464         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1465                 cqr->lpm &= dasd_path_get_opm(device);
1466                 if (!cqr->lpm)
1467                         cqr->lpm = dasd_path_get_opm(device);
1468         }
1469         if (cqr->cpmode == 1) {
1470                 rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
1471                                          (long) cqr, cqr->lpm);
1472         } else {
1473                 rc = ccw_device_start(device->cdev, cqr->cpaddr,
1474                                       (long) cqr, cqr->lpm, 0);
1475         }
1476         switch (rc) {
1477         case 0:
1478                 cqr->status = DASD_CQR_IN_IO;
1479                 break;
1480         case -EBUSY:
1481                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1482                               "start_IO: device busy, retry later");
1483                 break;
1484         case -EACCES:
1485                 /* -EACCES indicates that the request used only a subset of the
1486                  * available paths and all these paths are gone. If the lpm of
1487                  * this request was only a subset of the opm (e.g. the ppm) then
1488                  * we just do a retry with all available paths.
1489                  * If we already use the full opm, something is amiss, and we
1490                  * need a full path verification.
1491                  */
1492                 if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1493                         DBF_DEV_EVENT(DBF_WARNING, device,
1494                                       "start_IO: selected paths gone (%x)",
1495                                       cqr->lpm);
1496                 } else if (cqr->lpm != dasd_path_get_opm(device)) {
1497                         cqr->lpm = dasd_path_get_opm(device);
1498                         DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
1499                                       "start_IO: selected paths gone,"
1500                                       " retry on all paths");
1501                 } else {
1502                         DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1503                                       "start_IO: all paths in opm gone,"
1504                                       " do path verification");
1505                         dasd_generic_last_path_gone(device);
1506                         dasd_path_no_path(device);
1507                         dasd_path_set_tbvpm(device,
1508                                           ccw_device_get_path_mask(
1509                                                   device->cdev));
1510                 }
1511                 break;
1512         case -ENODEV:
1513                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1514                               "start_IO: -ENODEV device gone, retry");
1515                 break;
1516         case -EIO:
1517                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1518                               "start_IO: -EIO device gone, retry");
1519                 break;
1520         case -EINVAL:
1521                 /* most likely caused in power management context */
1522                 DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1523                               "start_IO: -EINVAL device currently "
1524                               "not accessible");
1525                 break;
1526         default:
1527                 /* internal error 11 - unknown rc */
1528                 snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
1529                 dev_err(&device->cdev->dev,
1530                         "An error occurred in the DASD device driver, "
1531                         "reason=%s\n", errorstring);
1532                 BUG();
1533                 break;
1534         }
1535         cqr->intrc = rc;
1536         return rc;
1537 }
1538 EXPORT_SYMBOL(dasd_start_IO);
1539
1540 /*
1541  * Timeout function for dasd devices. This is used for different purposes
1542  *  1) missing interrupt handler for normal operation
1543  *  2) delayed start of request where start_IO failed with -EBUSY
1544  *  3) timeout for missing state change interrupts
1545  * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
1546  * DASD_CQR_QUEUED for 2) and 3).
1547  */
1548 static void dasd_device_timeout(struct timer_list *t)
1549 {
1550         unsigned long flags;
1551         struct dasd_device *device;
1552
1553         device = from_timer(device, t, timer);
1554         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
1555         /* re-activate request queue */
1556         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1557         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1558         dasd_schedule_device_bh(device);
1559 }
1560
1561 /*
1562  * Setup timeout for a device in jiffies.
1563  */
1564 void dasd_device_set_timer(struct dasd_device *device, int expires)
1565 {
1566         if (expires == 0)
1567                 del_timer(&device->timer);
1568         else
1569                 mod_timer(&device->timer, jiffies + expires);
1570 }
1571 EXPORT_SYMBOL(dasd_device_set_timer);
1572
1573 /*
1574  * Clear timeout for a device.
1575  */
1576 void dasd_device_clear_timer(struct dasd_device *device)
1577 {
1578         del_timer(&device->timer);
1579 }
1580 EXPORT_SYMBOL(dasd_device_clear_timer);
1581
1582 static void dasd_handle_killed_request(struct ccw_device *cdev,
1583                                        unsigned long intparm)
1584 {
1585         struct dasd_ccw_req *cqr;
1586         struct dasd_device *device;
1587
1588         if (!intparm)
1589                 return;
1590         cqr = (struct dasd_ccw_req *) intparm;
1591         if (cqr->status != DASD_CQR_IN_IO) {
1592                 DBF_EVENT_DEVID(DBF_DEBUG, cdev,
1593                                 "invalid status in handle_killed_request: "
1594                                 "%02x", cqr->status);
1595                 return;
1596         }
1597
1598         device = dasd_device_from_cdev_locked(cdev);
1599         if (IS_ERR(device)) {
1600                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1601                                 "unable to get device from cdev");
1602                 return;
1603         }
1604
1605         if (!cqr->startdev ||
1606             device != cqr->startdev ||
1607             strncmp(cqr->startdev->discipline->ebcname,
1608                     (char *) &cqr->magic, 4)) {
1609                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1610                                 "invalid device in request");
1611                 dasd_put_device(device);
1612                 return;
1613         }
1614
1615         /* Schedule request to be retried. */
1616         cqr->status = DASD_CQR_QUEUED;
1617
1618         dasd_device_clear_timer(device);
1619         dasd_schedule_device_bh(device);
1620         dasd_put_device(device);
1621 }
1622
1623 void dasd_generic_handle_state_change(struct dasd_device *device)
1624 {
1625         /* First of all start sense subsystem status request. */
1626         dasd_eer_snss(device);
1627
1628         dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1629         dasd_schedule_device_bh(device);
1630         if (device->block) {
1631                 dasd_schedule_block_bh(device->block);
1632                 if (device->block->request_queue)
1633                         blk_mq_run_hw_queues(device->block->request_queue,
1634                                              true);
1635         }
1636 }
1637 EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
1638
1639 static int dasd_check_hpf_error(struct irb *irb)
1640 {
1641         return (scsw_tm_is_valid_schxs(&irb->scsw) &&
1642             (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX ||
1643              irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX));
1644 }
1645
1646 /*
1647  * Interrupt handler for "normal" ssch-io based dasd devices.
1648  */
1649 void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
1650                       struct irb *irb)
1651 {
1652         struct dasd_ccw_req *cqr, *next;
1653         struct dasd_device *device;
1654         unsigned long now;
1655         int nrf_suppressed = 0;
1656         int fp_suppressed = 0;
1657         u8 *sense = NULL;
1658         int expires;
1659
1660         cqr = (struct dasd_ccw_req *) intparm;
1661         if (IS_ERR(irb)) {
1662                 switch (PTR_ERR(irb)) {
1663                 case -EIO:
1664                         if (cqr && cqr->status == DASD_CQR_CLEAR_PENDING) {
1665                                 device = cqr->startdev;
1666                                 cqr->status = DASD_CQR_CLEARED;
1667                                 dasd_device_clear_timer(device);
1668                                 wake_up(&dasd_flush_wq);
1669                                 dasd_schedule_device_bh(device);
1670                                 return;
1671                         }
1672                         break;
1673                 case -ETIMEDOUT:
1674                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1675                                         "request timed out\n", __func__);
1676                         break;
1677                 default:
1678                         DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
1679                                         "unknown error %ld\n", __func__,
1680                                         PTR_ERR(irb));
1681                 }
1682                 dasd_handle_killed_request(cdev, intparm);
1683                 return;
1684         }
1685
1686         now = get_tod_clock();
1687         /* check for conditions that should be handled immediately */
1688         if (!cqr ||
1689             !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1690               scsw_cstat(&irb->scsw) == 0)) {
1691                 if (cqr)
1692                         memcpy(&cqr->irb, irb, sizeof(*irb));
1693                 device = dasd_device_from_cdev_locked(cdev);
1694                 if (IS_ERR(device))
1695                         return;
1696                 /* ignore unsolicited interrupts for DIAG discipline */
1697                 if (device->discipline == dasd_diag_discipline_pointer) {
1698                         dasd_put_device(device);
1699                         return;
1700                 }
1701
1702                 /*
1703                  * In some cases 'File Protected' or 'No Record Found' errors
1704                  * might be expected and debug log messages for the
1705                  * corresponding interrupts shouldn't be written then.
1706                  * Check if either of the according suppress bits is set.
1707                  */
1708                 sense = dasd_get_sense(irb);
1709                 if (sense) {
1710                         fp_suppressed = (sense[1] & SNS1_FILE_PROTECTED) &&
1711                                 test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags);
1712                         nrf_suppressed = (sense[1] & SNS1_NO_REC_FOUND) &&
1713                                 test_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
1714                 }
1715                 if (!(fp_suppressed || nrf_suppressed))
1716                         device->discipline->dump_sense_dbf(device, irb, "int");
1717
1718                 if (device->features & DASD_FEATURE_ERPLOG)
1719                         device->discipline->dump_sense(device, cqr, irb);
1720                 device->discipline->check_for_device_change(device, cqr, irb);
1721                 dasd_put_device(device);
1722         }
1723
1724         /* check for for attention message */
1725         if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
1726                 device = dasd_device_from_cdev_locked(cdev);
1727                 if (!IS_ERR(device)) {
1728                         device->discipline->check_attention(device,
1729                                                             irb->esw.esw1.lpum);
1730                         dasd_put_device(device);
1731                 }
1732         }
1733
1734         if (!cqr)
1735                 return;
1736
1737         device = (struct dasd_device *) cqr->startdev;
1738         if (!device ||
1739             strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1740                 DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
1741                                 "invalid device in request");
1742                 return;
1743         }
1744
1745         /* Check for clear pending */
1746         if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1747             scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1748                 cqr->status = DASD_CQR_CLEARED;
1749                 dasd_device_clear_timer(device);
1750                 wake_up(&dasd_flush_wq);
1751                 dasd_schedule_device_bh(device);
1752                 return;
1753         }
1754
1755         /* check status - the request might have been killed by dyn detach */
1756         if (cqr->status != DASD_CQR_IN_IO) {
1757                 DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
1758                               "status %02x", dev_name(&cdev->dev), cqr->status);
1759                 return;
1760         }
1761
1762         next = NULL;
1763         expires = 0;
1764         if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
1765             scsw_cstat(&irb->scsw) == 0) {
1766                 /* request was completed successfully */
1767                 cqr->status = DASD_CQR_SUCCESS;
1768                 cqr->stopclk = now;
1769                 /* Start first request on queue if possible -> fast_io. */
1770                 if (cqr->devlist.next != &device->ccw_queue) {
1771                         next = list_entry(cqr->devlist.next,
1772                                           struct dasd_ccw_req, devlist);
1773                 }
1774         } else {  /* error */
1775                 /* check for HPF error
1776                  * call discipline function to requeue all requests
1777                  * and disable HPF accordingly
1778                  */
1779                 if (cqr->cpmode && dasd_check_hpf_error(irb) &&
1780                     device->discipline->handle_hpf_error)
1781                         device->discipline->handle_hpf_error(device, irb);
1782                 /*
1783                  * If we don't want complex ERP for this request, then just
1784                  * reset this and retry it in the fastpath
1785                  */
1786                 if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1787                     cqr->retries > 0) {
1788                         if (cqr->lpm == dasd_path_get_opm(device))
1789                                 DBF_DEV_EVENT(DBF_DEBUG, device,
1790                                               "default ERP in fastpath "
1791                                               "(%i retries left)",
1792                                               cqr->retries);
1793                         if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
1794                                 cqr->lpm = dasd_path_get_opm(device);
1795                         cqr->status = DASD_CQR_QUEUED;
1796                         next = cqr;
1797                 } else
1798                         cqr->status = DASD_CQR_ERROR;
1799         }
1800         if (next && (next->status == DASD_CQR_QUEUED) &&
1801             (!device->stopped)) {
1802                 if (device->discipline->start_IO(next) == 0)
1803                         expires = next->expires;
1804         }
1805         if (expires != 0)
1806                 dasd_device_set_timer(device, expires);
1807         else
1808                 dasd_device_clear_timer(device);
1809         dasd_schedule_device_bh(device);
1810 }
1811 EXPORT_SYMBOL(dasd_int_handler);
1812
1813 enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
1814 {
1815         struct dasd_device *device;
1816
1817         device = dasd_device_from_cdev_locked(cdev);
1818
1819         if (IS_ERR(device))
1820                 goto out;
1821         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
1822            device->state != device->target ||
1823            !device->discipline->check_for_device_change){
1824                 dasd_put_device(device);
1825                 goto out;
1826         }
1827         if (device->discipline->dump_sense_dbf)
1828                 device->discipline->dump_sense_dbf(device, irb, "uc");
1829         device->discipline->check_for_device_change(device, NULL, irb);
1830         dasd_put_device(device);
1831 out:
1832         return UC_TODO_RETRY;
1833 }
1834 EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);
1835
1836 /*
1837  * If we have an error on a dasd_block layer request then we cancel
1838  * and return all further requests from the same dasd_block as well.
1839  */
1840 static void __dasd_device_recovery(struct dasd_device *device,
1841                                    struct dasd_ccw_req *ref_cqr)
1842 {
1843         struct list_head *l, *n;
1844         struct dasd_ccw_req *cqr;
1845
1846         /*
1847          * only requeue request that came from the dasd_block layer
1848          */
1849         if (!ref_cqr->block)
1850                 return;
1851
1852         list_for_each_safe(l, n, &device->ccw_queue) {
1853                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1854                 if (cqr->status == DASD_CQR_QUEUED &&
1855                     ref_cqr->block == cqr->block) {
1856                         cqr->status = DASD_CQR_CLEARED;
1857                 }
1858         }
1859 };
1860
1861 /*
1862  * Remove those ccw requests from the queue that need to be returned
1863  * to the upper layer.
1864  */
1865 static void __dasd_device_process_ccw_queue(struct dasd_device *device,
1866                                             struct list_head *final_queue)
1867 {
1868         struct list_head *l, *n;
1869         struct dasd_ccw_req *cqr;
1870
1871         /* Process request with final status. */
1872         list_for_each_safe(l, n, &device->ccw_queue) {
1873                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1874
1875                 /* Skip any non-final request. */
1876                 if (cqr->status == DASD_CQR_QUEUED ||
1877                     cqr->status == DASD_CQR_IN_IO ||
1878                     cqr->status == DASD_CQR_CLEAR_PENDING)
1879                         continue;
1880                 if (cqr->status == DASD_CQR_ERROR) {
1881                         __dasd_device_recovery(device, cqr);
1882                 }
1883                 /* Rechain finished requests to final queue */
1884                 list_move_tail(&cqr->devlist, final_queue);
1885         }
1886 }
1887
1888 /*
1889  * the cqrs from the final queue are returned to the upper layer
1890  * by setting a dasd_block state and calling the callback function
1891  */
1892 static void __dasd_device_process_final_queue(struct dasd_device *device,
1893                                               struct list_head *final_queue)
1894 {
1895         struct list_head *l, *n;
1896         struct dasd_ccw_req *cqr;
1897         struct dasd_block *block;
1898         void (*callback)(struct dasd_ccw_req *, void *data);
1899         void *callback_data;
1900         char errorstring[ERRORLENGTH];
1901
1902         list_for_each_safe(l, n, final_queue) {
1903                 cqr = list_entry(l, struct dasd_ccw_req, devlist);
1904                 list_del_init(&cqr->devlist);
1905                 block = cqr->block;
1906                 callback = cqr->callback;
1907                 callback_data = cqr->callback_data;
1908                 if (block)
1909                         spin_lock_bh(&block->queue_lock);
1910                 switch (cqr->status) {
1911                 case DASD_CQR_SUCCESS:
1912                         cqr->status = DASD_CQR_DONE;
1913                         break;
1914                 case DASD_CQR_ERROR:
1915                         cqr->status = DASD_CQR_NEED_ERP;
1916                         break;
1917                 case DASD_CQR_CLEARED:
1918                         cqr->status = DASD_CQR_TERMINATED;
1919                         break;
1920                 default:
1921                         /* internal error 12 - wrong cqr status*/
1922                         snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
1923                         dev_err(&device->cdev->dev,
1924                                 "An error occurred in the DASD device driver, "
1925                                 "reason=%s\n", errorstring);
1926                         BUG();
1927                 }
1928                 if (cqr->callback != NULL)
1929                         (callback)(cqr, callback_data);
1930                 if (block)
1931                         spin_unlock_bh(&block->queue_lock);
1932         }
1933 }
1934
1935 /*
1936  * Take a look at the first request on the ccw queue and check
1937  * if it reached its expire time. If so, terminate the IO.
1938  */
1939 static void __dasd_device_check_expire(struct dasd_device *device)
1940 {
1941         struct dasd_ccw_req *cqr;
1942
1943         if (list_empty(&device->ccw_queue))
1944                 return;
1945         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1946         if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
1947             (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
1948                 if (test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1949                         /*
1950                          * IO in safe offline processing should not
1951                          * run out of retries
1952                          */
1953                         cqr->retries++;
1954                 }
1955                 if (device->discipline->term_IO(cqr) != 0) {
1956                         /* Hmpf, try again in 5 sec */
1957                         dev_err(&device->cdev->dev,
1958                                 "cqr %p timed out (%lus) but cannot be "
1959                                 "ended, retrying in 5 s\n",
1960                                 cqr, (cqr->expires/HZ));
1961                         cqr->expires += 5*HZ;
1962                         dasd_device_set_timer(device, 5*HZ);
1963                 } else {
1964                         dev_err(&device->cdev->dev,
1965                                 "cqr %p timed out (%lus), %i retries "
1966                                 "remaining\n", cqr, (cqr->expires/HZ),
1967                                 cqr->retries);
1968                 }
1969         }
1970 }
1971
1972 /*
1973  * return 1 when device is not eligible for IO
1974  */
1975 static int __dasd_device_is_unusable(struct dasd_device *device,
1976                                      struct dasd_ccw_req *cqr)
1977 {
1978         int mask = ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM);
1979
1980         if (test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
1981             !test_bit(DASD_FLAG_SAFE_OFFLINE_RUNNING, &device->flags)) {
1982                 /*
1983                  * dasd is being set offline
1984                  * but it is no safe offline where we have to allow I/O
1985                  */
1986                 return 1;
1987         }
1988         if (device->stopped) {
1989                 if (device->stopped & mask) {
1990                         /* stopped and CQR will not change that. */
1991                         return 1;
1992                 }
1993                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
1994                         /* CQR is not able to change device to
1995                          * operational. */
1996                         return 1;
1997                 }
1998                 /* CQR required to get device operational. */
1999         }
2000         return 0;
2001 }
2002
2003 /*
2004  * Take a look at the first request on the ccw queue and check
2005  * if it needs to be started.
2006  */
2007 static void __dasd_device_start_head(struct dasd_device *device)
2008 {
2009         struct dasd_ccw_req *cqr;
2010         int rc;
2011
2012         if (list_empty(&device->ccw_queue))
2013                 return;
2014         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2015         if (cqr->status != DASD_CQR_QUEUED)
2016                 return;
2017         /* if device is not usable return request to upper layer */
2018         if (__dasd_device_is_unusable(device, cqr)) {
2019                 cqr->intrc = -EAGAIN;
2020                 cqr->status = DASD_CQR_CLEARED;
2021                 dasd_schedule_device_bh(device);
2022                 return;
2023         }
2024
2025         rc = device->discipline->start_IO(cqr);
2026         if (rc == 0)
2027                 dasd_device_set_timer(device, cqr->expires);
2028         else if (rc == -EACCES) {
2029                 dasd_schedule_device_bh(device);
2030         } else
2031                 /* Hmpf, try again in 1/2 sec */
2032                 dasd_device_set_timer(device, 50);
2033 }
2034
2035 static void __dasd_device_check_path_events(struct dasd_device *device)
2036 {
2037         int rc;
2038
2039         if (!dasd_path_get_tbvpm(device))
2040                 return;
2041
2042         if (device->stopped &
2043             ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
2044                 return;
2045         rc = device->discipline->verify_path(device,
2046                                              dasd_path_get_tbvpm(device));
2047         if (rc)
2048                 dasd_device_set_timer(device, 50);
2049         else
2050                 dasd_path_clear_all_verify(device);
2051 };
2052
2053 /*
2054  * Go through all request on the dasd_device request queue,
2055  * terminate them on the cdev if necessary, and return them to the
2056  * submitting layer via callback.
2057  * Note:
2058  * Make sure that all 'submitting layers' still exist when
2059  * this function is called!. In other words, when 'device' is a base
2060  * device then all block layer requests must have been removed before
2061  * via dasd_flush_block_queue.
2062  */
2063 int dasd_flush_device_queue(struct dasd_device *device)
2064 {
2065         struct dasd_ccw_req *cqr, *n;
2066         int rc;
2067         struct list_head flush_queue;
2068
2069         INIT_LIST_HEAD(&flush_queue);
2070         spin_lock_irq(get_ccwdev_lock(device->cdev));
2071         rc = 0;
2072         list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
2073                 /* Check status and move request to flush_queue */
2074                 switch (cqr->status) {
2075                 case DASD_CQR_IN_IO:
2076                         rc = device->discipline->term_IO(cqr);
2077                         if (rc) {
2078                                 /* unable to terminate requeust */
2079                                 dev_err(&device->cdev->dev,
2080                                         "Flushing the DASD request queue "
2081                                         "failed for request %p\n", cqr);
2082                                 /* stop flush processing */
2083                                 goto finished;
2084                         }
2085                         break;
2086                 case DASD_CQR_QUEUED:
2087                         cqr->stopclk = get_tod_clock();
2088                         cqr->status = DASD_CQR_CLEARED;
2089                         break;
2090                 default: /* no need to modify the others */
2091                         break;
2092                 }
2093                 list_move_tail(&cqr->devlist, &flush_queue);
2094         }
2095 finished:
2096         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2097         /*
2098          * After this point all requests must be in state CLEAR_PENDING,
2099          * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
2100          * one of the others.
2101          */
2102         list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
2103                 wait_event(dasd_flush_wq,
2104                            (cqr->status != DASD_CQR_CLEAR_PENDING));
2105         /*
2106          * Now set each request back to TERMINATED, DONE or NEED_ERP
2107          * and call the callback function of flushed requests
2108          */
2109         __dasd_device_process_final_queue(device, &flush_queue);
2110         return rc;
2111 }
2112 EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
2113
2114 /*
2115  * Acquire the device lock and process queues for the device.
2116  */
2117 static void dasd_device_tasklet(struct dasd_device *device)
2118 {
2119         struct list_head final_queue;
2120
2121         atomic_set (&device->tasklet_scheduled, 0);
2122         INIT_LIST_HEAD(&final_queue);
2123         spin_lock_irq(get_ccwdev_lock(device->cdev));
2124         /* Check expire time of first request on the ccw queue. */
2125         __dasd_device_check_expire(device);
2126         /* find final requests on ccw queue */
2127         __dasd_device_process_ccw_queue(device, &final_queue);
2128         __dasd_device_check_path_events(device);
2129         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2130         /* Now call the callback function of requests with final status */
2131         __dasd_device_process_final_queue(device, &final_queue);
2132         spin_lock_irq(get_ccwdev_lock(device->cdev));
2133         /* Now check if the head of the ccw queue needs to be started. */
2134         __dasd_device_start_head(device);
2135         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2136         if (waitqueue_active(&shutdown_waitq))
2137                 wake_up(&shutdown_waitq);
2138         dasd_put_device(device);
2139 }
2140
2141 /*
2142  * Schedules a call to dasd_tasklet over the device tasklet.
2143  */
2144 void dasd_schedule_device_bh(struct dasd_device *device)
2145 {
2146         /* Protect against rescheduling. */
2147         if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
2148                 return;
2149         dasd_get_device(device);
2150         tasklet_hi_schedule(&device->tasklet);
2151 }
2152 EXPORT_SYMBOL(dasd_schedule_device_bh);
2153
2154 void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
2155 {
2156         device->stopped |= bits;
2157 }
2158 EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);
2159
2160 void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
2161 {
2162         device->stopped &= ~bits;
2163         if (!device->stopped)
2164                 wake_up(&generic_waitq);
2165 }
2166 EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);
2167
2168 /*
2169  * Queue a request to the head of the device ccw_queue.
2170  * Start the I/O if possible.
2171  */
2172 void dasd_add_request_head(struct dasd_ccw_req *cqr)
2173 {
2174         struct dasd_device *device;
2175         unsigned long flags;
2176
2177         device = cqr->startdev;
2178         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2179         cqr->status = DASD_CQR_QUEUED;
2180         list_add(&cqr->devlist, &device->ccw_queue);
2181         /* let the bh start the request to keep them in order */
2182         dasd_schedule_device_bh(device);
2183         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2184 }
2185 EXPORT_SYMBOL(dasd_add_request_head);
2186
2187 /*
2188  * Queue a request to the tail of the device ccw_queue.
2189  * Start the I/O if possible.
2190  */
2191 void dasd_add_request_tail(struct dasd_ccw_req *cqr)
2192 {
2193         struct dasd_device *device;
2194         unsigned long flags;
2195
2196         device = cqr->startdev;
2197         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2198         cqr->status = DASD_CQR_QUEUED;
2199         list_add_tail(&cqr->devlist, &device->ccw_queue);
2200         /* let the bh start the request to keep them in order */
2201         dasd_schedule_device_bh(device);
2202         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2203 }
2204 EXPORT_SYMBOL(dasd_add_request_tail);
2205
2206 /*
2207  * Wakeup helper for the 'sleep_on' functions.
2208  */
2209 void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
2210 {
2211         spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2212         cqr->callback_data = DASD_SLEEPON_END_TAG;
2213         spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
2214         wake_up(&generic_waitq);
2215 }
2216 EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
2217
2218 static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
2219 {
2220         struct dasd_device *device;
2221         int rc;
2222
2223         device = cqr->startdev;
2224         spin_lock_irq(get_ccwdev_lock(device->cdev));
2225         rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
2226         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2227         return rc;
2228 }
2229
2230 /*
2231  * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
2232  */
2233 static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
2234 {
2235         struct dasd_device *device;
2236         dasd_erp_fn_t erp_fn;
2237
2238         if (cqr->status == DASD_CQR_FILLED)
2239                 return 0;
2240         device = cqr->startdev;
2241         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2242                 if (cqr->status == DASD_CQR_TERMINATED) {
2243                         device->discipline->handle_terminated_request(cqr);
2244                         return 1;
2245                 }
2246                 if (cqr->status == DASD_CQR_NEED_ERP) {
2247                         erp_fn = device->discipline->erp_action(cqr);
2248                         erp_fn(cqr);
2249                         return 1;
2250                 }
2251                 if (cqr->status == DASD_CQR_FAILED)
2252                         dasd_log_sense(cqr, &cqr->irb);
2253                 if (cqr->refers) {
2254                         __dasd_process_erp(device, cqr);
2255                         return 1;
2256                 }
2257         }
2258         return 0;
2259 }
2260
2261 static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
2262 {
2263         if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
2264                 if (cqr->refers) /* erp is not done yet */
2265                         return 1;
2266                 return ((cqr->status != DASD_CQR_DONE) &&
2267                         (cqr->status != DASD_CQR_FAILED));
2268         } else
2269                 return (cqr->status == DASD_CQR_FILLED);
2270 }
2271
2272 static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
2273 {
2274         struct dasd_device *device;
2275         int rc;
2276         struct list_head ccw_queue;
2277         struct dasd_ccw_req *cqr;
2278
2279         INIT_LIST_HEAD(&ccw_queue);
2280         maincqr->status = DASD_CQR_FILLED;
2281         device = maincqr->startdev;
2282         list_add(&maincqr->blocklist, &ccw_queue);
2283         for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
2284              cqr = list_first_entry(&ccw_queue,
2285                                     struct dasd_ccw_req, blocklist)) {
2286
2287                 if (__dasd_sleep_on_erp(cqr))
2288                         continue;
2289                 if (cqr->status != DASD_CQR_FILLED) /* could be failed */
2290                         continue;
2291                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2292                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2293                         cqr->status = DASD_CQR_FAILED;
2294                         cqr->intrc = -EPERM;
2295                         continue;
2296                 }
2297                 /* Non-temporary stop condition will trigger fail fast */
2298                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2299                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2300                     (!dasd_eer_enabled(device))) {
2301                         cqr->status = DASD_CQR_FAILED;
2302                         cqr->intrc = -ENOLINK;
2303                         continue;
2304                 }
2305                 /*
2306                  * Don't try to start requests if device is in
2307                  * offline processing, it might wait forever
2308                  */
2309                 if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
2310                         cqr->status = DASD_CQR_FAILED;
2311                         cqr->intrc = -ENODEV;
2312                         continue;
2313                 }
2314                 /*
2315                  * Don't try to start requests if device is stopped
2316                  * except path verification requests
2317                  */
2318                 if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
2319                         if (interruptible) {
2320                                 rc = wait_event_interruptible(
2321                                         generic_waitq, !(device->stopped));
2322                                 if (rc == -ERESTARTSYS) {
2323                                         cqr->status = DASD_CQR_FAILED;
2324                                         maincqr->intrc = rc;
2325                                         continue;
2326                                 }
2327                         } else
2328                                 wait_event(generic_waitq, !(device->stopped));
2329                 }
2330                 if (!cqr->callback)
2331                         cqr->callback = dasd_wakeup_cb;
2332
2333                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2334                 dasd_add_request_tail(cqr);
2335                 if (interruptible) {
2336                         rc = wait_event_interruptible(
2337                                 generic_waitq, _wait_for_wakeup(cqr));
2338                         if (rc == -ERESTARTSYS) {
2339                                 dasd_cancel_req(cqr);
2340                                 /* wait (non-interruptible) for final status */
2341                                 wait_event(generic_waitq,
2342                                            _wait_for_wakeup(cqr));
2343                                 cqr->status = DASD_CQR_FAILED;
2344                                 maincqr->intrc = rc;
2345                                 continue;
2346                         }
2347                 } else
2348                         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2349         }
2350
2351         maincqr->endclk = get_tod_clock();
2352         if ((maincqr->status != DASD_CQR_DONE) &&
2353             (maincqr->intrc != -ERESTARTSYS))
2354                 dasd_log_sense(maincqr, &maincqr->irb);
2355         if (maincqr->status == DASD_CQR_DONE)
2356                 rc = 0;
2357         else if (maincqr->intrc)
2358                 rc = maincqr->intrc;
2359         else
2360                 rc = -EIO;
2361         return rc;
2362 }
2363
2364 static inline int _wait_for_wakeup_queue(struct list_head *ccw_queue)
2365 {
2366         struct dasd_ccw_req *cqr;
2367
2368         list_for_each_entry(cqr, ccw_queue, blocklist) {
2369                 if (cqr->callback_data != DASD_SLEEPON_END_TAG)
2370                         return 0;
2371         }
2372
2373         return 1;
2374 }
2375
2376 static int _dasd_sleep_on_queue(struct list_head *ccw_queue, int interruptible)
2377 {
2378         struct dasd_device *device;
2379         struct dasd_ccw_req *cqr, *n;
2380         u8 *sense = NULL;
2381         int rc;
2382
2383 retry:
2384         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2385                 device = cqr->startdev;
2386                 if (cqr->status != DASD_CQR_FILLED) /*could be failed*/
2387                         continue;
2388
2389                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2390                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2391                         cqr->status = DASD_CQR_FAILED;
2392                         cqr->intrc = -EPERM;
2393                         continue;
2394                 }
2395                 /*Non-temporary stop condition will trigger fail fast*/
2396                 if (device->stopped & ~DASD_STOPPED_PENDING &&
2397                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2398                     !dasd_eer_enabled(device)) {
2399                         cqr->status = DASD_CQR_FAILED;
2400                         cqr->intrc = -EAGAIN;
2401                         continue;
2402                 }
2403
2404                 /*Don't try to start requests if device is stopped*/
2405                 if (interruptible) {
2406                         rc = wait_event_interruptible(
2407                                 generic_waitq, !device->stopped);
2408                         if (rc == -ERESTARTSYS) {
2409                                 cqr->status = DASD_CQR_FAILED;
2410                                 cqr->intrc = rc;
2411                                 continue;
2412                         }
2413                 } else
2414                         wait_event(generic_waitq, !(device->stopped));
2415
2416                 if (!cqr->callback)
2417                         cqr->callback = dasd_wakeup_cb;
2418                 cqr->callback_data = DASD_SLEEPON_START_TAG;
2419                 dasd_add_request_tail(cqr);
2420         }
2421
2422         wait_event(generic_waitq, _wait_for_wakeup_queue(ccw_queue));
2423
2424         rc = 0;
2425         list_for_each_entry_safe(cqr, n, ccw_queue, blocklist) {
2426                 /*
2427                  * In some cases the 'File Protected' or 'Incorrect Length'
2428                  * error might be expected and error recovery would be
2429                  * unnecessary in these cases.  Check if the according suppress
2430                  * bit is set.
2431                  */
2432                 sense = dasd_get_sense(&cqr->irb);
2433                 if (sense && sense[1] & SNS1_FILE_PROTECTED &&
2434                     test_bit(DASD_CQR_SUPPRESS_FP, &cqr->flags))
2435                         continue;
2436                 if (scsw_cstat(&cqr->irb.scsw) == 0x40 &&
2437                     test_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags))
2438                         continue;
2439
2440                 /*
2441                  * for alias devices simplify error recovery and
2442                  * return to upper layer
2443                  * do not skip ERP requests
2444                  */
2445                 if (cqr->startdev != cqr->basedev && !cqr->refers &&
2446                     (cqr->status == DASD_CQR_TERMINATED ||
2447                      cqr->status == DASD_CQR_NEED_ERP))
2448                         return -EAGAIN;
2449
2450                 /* normal recovery for basedev IO */
2451                 if (__dasd_sleep_on_erp(cqr))
2452                         /* handle erp first */
2453                         goto retry;
2454         }
2455
2456         return 0;
2457 }
2458
2459 /*
2460  * Queue a request to the tail of the device ccw_queue and wait for
2461  * it's completion.
2462  */
2463 int dasd_sleep_on(struct dasd_ccw_req *cqr)
2464 {
2465         return _dasd_sleep_on(cqr, 0);
2466 }
2467 EXPORT_SYMBOL(dasd_sleep_on);
2468
2469 /*
2470  * Start requests from a ccw_queue and wait for their completion.
2471  */
2472 int dasd_sleep_on_queue(struct list_head *ccw_queue)
2473 {
2474         return _dasd_sleep_on_queue(ccw_queue, 0);
2475 }
2476 EXPORT_SYMBOL(dasd_sleep_on_queue);
2477
2478 /*
2479  * Queue a request to the tail of the device ccw_queue and wait
2480  * interruptible for it's completion.
2481  */
2482 int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
2483 {
2484         return _dasd_sleep_on(cqr, 1);
2485 }
2486 EXPORT_SYMBOL(dasd_sleep_on_interruptible);
2487
2488 /*
2489  * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
2490  * for eckd devices) the currently running request has to be terminated
2491  * and be put back to status queued, before the special request is added
2492  * to the head of the queue. Then the special request is waited on normally.
2493  */
2494 static inline int _dasd_term_running_cqr(struct dasd_device *device)
2495 {
2496         struct dasd_ccw_req *cqr;
2497         int rc;
2498
2499         if (list_empty(&device->ccw_queue))
2500                 return 0;
2501         cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2502         rc = device->discipline->term_IO(cqr);
2503         if (!rc)
2504                 /*
2505                  * CQR terminated because a more important request is pending.
2506                  * Undo decreasing of retry counter because this is
2507                  * not an error case.
2508                  */
2509                 cqr->retries++;
2510         return rc;
2511 }
2512
2513 int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
2514 {
2515         struct dasd_device *device;
2516         int rc;
2517
2518         device = cqr->startdev;
2519         if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
2520             !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2521                 cqr->status = DASD_CQR_FAILED;
2522                 cqr->intrc = -EPERM;
2523                 return -EIO;
2524         }
2525         spin_lock_irq(get_ccwdev_lock(device->cdev));
2526         rc = _dasd_term_running_cqr(device);
2527         if (rc) {
2528                 spin_unlock_irq(get_ccwdev_lock(device->cdev));
2529                 return rc;
2530         }
2531         cqr->callback = dasd_wakeup_cb;
2532         cqr->callback_data = DASD_SLEEPON_START_TAG;
2533         cqr->status = DASD_CQR_QUEUED;
2534         /*
2535          * add new request as second
2536          * first the terminated cqr needs to be finished
2537          */
2538         list_add(&cqr->devlist, device->ccw_queue.next);
2539
2540         /* let the bh start the request to keep them in order */
2541         dasd_schedule_device_bh(device);
2542
2543         spin_unlock_irq(get_ccwdev_lock(device->cdev));
2544
2545         wait_event(generic_waitq, _wait_for_wakeup(cqr));
2546
2547         if (cqr->status == DASD_CQR_DONE)
2548                 rc = 0;
2549         else if (cqr->intrc)
2550                 rc = cqr->intrc;
2551         else
2552                 rc = -EIO;
2553
2554         /* kick tasklets */
2555         dasd_schedule_device_bh(device);
2556         if (device->block)
2557                 dasd_schedule_block_bh(device->block);
2558
2559         return rc;
2560 }
2561 EXPORT_SYMBOL(dasd_sleep_on_immediatly);
2562
2563 /*
2564  * Cancels a request that was started with dasd_sleep_on_req.
2565  * This is useful to timeout requests. The request will be
2566  * terminated if it is currently in i/o.
2567  * Returns 0 if request termination was successful
2568  *         negative error code if termination failed
2569  * Cancellation of a request is an asynchronous operation! The calling
2570  * function has to wait until the request is properly returned via callback.
2571  */
2572 int dasd_cancel_req(struct dasd_ccw_req *cqr)
2573 {
2574         struct dasd_device *device = cqr->startdev;
2575         unsigned long flags;
2576         int rc;
2577
2578         rc = 0;
2579         spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2580         switch (cqr->status) {
2581         case DASD_CQR_QUEUED:
2582                 /* request was not started - just set to cleared */
2583                 cqr->status = DASD_CQR_CLEARED;
2584                 break;
2585         case DASD_CQR_IN_IO:
2586                 /* request in IO - terminate IO and release again */
2587                 rc = device->discipline->term_IO(cqr);
2588                 if (rc) {
2589                         dev_err(&device->cdev->dev,
2590                                 "Cancelling request %p failed with rc=%d\n",
2591                                 cqr, rc);
2592                 } else {
2593                         cqr->stopclk = get_tod_clock();
2594                 }
2595                 break;
2596         default: /* already finished or clear pending - do nothing */
2597                 break;
2598         }
2599         spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
2600         dasd_schedule_device_bh(device);
2601         return rc;
2602 }
2603 EXPORT_SYMBOL(dasd_cancel_req);
2604
2605 /*
2606  * SECTION: Operations of the dasd_block layer.
2607  */
2608
2609 /*
2610  * Timeout function for dasd_block. This is used when the block layer
2611  * is waiting for something that may not come reliably, (e.g. a state
2612  * change interrupt)
2613  */
2614 static void dasd_block_timeout(struct timer_list *t)
2615 {
2616         unsigned long flags;
2617         struct dasd_block *block;
2618
2619         block = from_timer(block, t, timer);
2620         spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
2621         /* re-activate request queue */
2622         dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2623         spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
2624         dasd_schedule_block_bh(block);
2625         blk_mq_run_hw_queues(block->request_queue, true);
2626 }
2627
2628 /*
2629  * Setup timeout for a dasd_block in jiffies.
2630  */
2631 void dasd_block_set_timer(struct dasd_block *block, int expires)
2632 {
2633         if (expires == 0)
2634                 del_timer(&block->timer);
2635         else
2636                 mod_timer(&block->timer, jiffies + expires);
2637 }
2638 EXPORT_SYMBOL(dasd_block_set_timer);
2639
2640 /*
2641  * Clear timeout for a dasd_block.
2642  */
2643 void dasd_block_clear_timer(struct dasd_block *block)
2644 {
2645         del_timer(&block->timer);
2646 }
2647 EXPORT_SYMBOL(dasd_block_clear_timer);
2648
2649 /*
2650  * Process finished error recovery ccw.
2651  */
2652 static void __dasd_process_erp(struct dasd_device *device,
2653                                struct dasd_ccw_req *cqr)
2654 {
2655         dasd_erp_fn_t erp_fn;
2656
2657         if (cqr->status == DASD_CQR_DONE)
2658                 DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
2659         else
2660                 dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2661         erp_fn = device->discipline->erp_postaction(cqr);
2662         erp_fn(cqr);
2663 }
2664
2665 static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
2666 {
2667         struct request *req;
2668         blk_status_t error = BLK_STS_OK;
2669         int status;
2670
2671         req = (struct request *) cqr->callback_data;
2672         dasd_profile_end(cqr->block, cqr, req);
2673
2674         status = cqr->block->base->discipline->free_cp(cqr, req);
2675         if (status < 0)
2676                 error = errno_to_blk_status(status);
2677         else if (status == 0) {
2678                 switch (cqr->intrc) {
2679                 case -EPERM:
2680                         error = BLK_STS_NEXUS;
2681                         break;
2682                 case -ENOLINK:
2683                         error = BLK_STS_TRANSPORT;
2684                         break;
2685                 case -ETIMEDOUT:
2686                         error = BLK_STS_TIMEOUT;
2687                         break;
2688                 default:
2689                         error = BLK_STS_IOERR;
2690                         break;
2691                 }
2692         }
2693
2694         /*
2695          * We need to take care for ETIMEDOUT errors here since the
2696          * complete callback does not get called in this case.
2697          * Take care of all errors here and avoid additional code to
2698          * transfer the error value to the complete callback.
2699          */
2700         if (error) {
2701                 blk_mq_end_request(req, error);
2702                 blk_mq_run_hw_queues(req->q, true);
2703         } else {
2704                 blk_mq_complete_request(req);
2705         }
2706 }
2707
2708 /*
2709  * Process ccw request queue.
2710  */
2711 static void __dasd_process_block_ccw_queue(struct dasd_block *block,
2712                                            struct list_head *final_queue)
2713 {
2714         struct list_head *l, *n;
2715         struct dasd_ccw_req *cqr;
2716         dasd_erp_fn_t erp_fn;
2717         unsigned long flags;
2718         struct dasd_device *base = block->base;
2719
2720 restart:
2721         /* Process request with final status. */
2722         list_for_each_safe(l, n, &block->ccw_queue) {
2723                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2724                 if (cqr->status != DASD_CQR_DONE &&
2725                     cqr->status != DASD_CQR_FAILED &&
2726                     cqr->status != DASD_CQR_NEED_ERP &&
2727                     cqr->status != DASD_CQR_TERMINATED)
2728                         continue;
2729
2730                 if (cqr->status == DASD_CQR_TERMINATED) {
2731                         base->discipline->handle_terminated_request(cqr);
2732                         goto restart;
2733                 }
2734
2735                 /*  Process requests that may be recovered */
2736                 if (cqr->status == DASD_CQR_NEED_ERP) {
2737                         erp_fn = base->discipline->erp_action(cqr);
2738                         if (IS_ERR(erp_fn(cqr)))
2739                                 continue;
2740                         goto restart;
2741                 }
2742
2743                 /* log sense for fatal error */
2744                 if (cqr->status == DASD_CQR_FAILED) {
2745                         dasd_log_sense(cqr, &cqr->irb);
2746                 }
2747
2748                 /* First of all call extended error reporting. */
2749                 if (dasd_eer_enabled(base) &&
2750                     cqr->status == DASD_CQR_FAILED) {
2751                         dasd_eer_write(base, cqr, DASD_EER_FATALERROR);
2752
2753                         /* restart request  */
2754                         cqr->status = DASD_CQR_FILLED;
2755                         cqr->retries = 255;
2756                         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2757                         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2758                         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
2759                                                flags);
2760                         goto restart;
2761                 }
2762
2763                 /* Process finished ERP request. */
2764                 if (cqr->refers) {
2765                         __dasd_process_erp(base, cqr);
2766                         goto restart;
2767                 }
2768
2769                 /* Rechain finished requests to final queue */
2770                 cqr->endclk = get_tod_clock();
2771                 list_move_tail(&cqr->blocklist, final_queue);
2772         }
2773 }
2774
2775 static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
2776 {
2777         dasd_schedule_block_bh(cqr->block);
2778 }
2779
2780 static void __dasd_block_start_head(struct dasd_block *block)
2781 {
2782         struct dasd_ccw_req *cqr;
2783
2784         if (list_empty(&block->ccw_queue))
2785                 return;
2786         /* We allways begin with the first requests on the queue, as some
2787          * of previously started requests have to be enqueued on a
2788          * dasd_device again for error recovery.
2789          */
2790         list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
2791                 if (cqr->status != DASD_CQR_FILLED)
2792                         continue;
2793                 if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
2794                     !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
2795                         cqr->status = DASD_CQR_FAILED;
2796                         cqr->intrc = -EPERM;
2797                         dasd_schedule_block_bh(block);
2798                         continue;
2799                 }
2800                 /* Non-temporary stop condition will trigger fail fast */
2801                 if (block->base->stopped & ~DASD_STOPPED_PENDING &&
2802                     test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
2803                     (!dasd_eer_enabled(block->base))) {
2804                         cqr->status = DASD_CQR_FAILED;
2805                         cqr->intrc = -ENOLINK;
2806                         dasd_schedule_block_bh(block);
2807                         continue;
2808                 }
2809                 /* Don't try to start requests if device is stopped */
2810                 if (block->base->stopped)
2811                         return;
2812
2813                 /* just a fail safe check, should not happen */
2814                 if (!cqr->startdev)
2815                         cqr->startdev = block->base;
2816
2817                 /* make sure that the requests we submit find their way back */
2818                 cqr->callback = dasd_return_cqr_cb;
2819
2820                 dasd_add_request_tail(cqr);
2821         }
2822 }
2823
2824 /*
2825  * Central dasd_block layer routine. Takes requests from the generic
2826  * block layer request queue, creates ccw requests, enqueues them on
2827  * a dasd_device and processes ccw requests that have been returned.
2828  */
2829 static void dasd_block_tasklet(struct dasd_block *block)
2830 {
2831         struct list_head final_queue;
2832         struct list_head *l, *n;
2833         struct dasd_ccw_req *cqr;
2834         struct dasd_queue *dq;
2835
2836         atomic_set(&block->tasklet_scheduled, 0);
2837         INIT_LIST_HEAD(&final_queue);
2838         spin_lock_irq(&block->queue_lock);
2839         /* Finish off requests on ccw queue */
2840         __dasd_process_block_ccw_queue(block, &final_queue);
2841         spin_unlock_irq(&block->queue_lock);
2842
2843         /* Now call the callback function of requests with final status */
2844         list_for_each_safe(l, n, &final_queue) {
2845                 cqr = list_entry(l, struct dasd_ccw_req, blocklist);
2846                 dq = cqr->dq;
2847                 spin_lock_irq(&dq->lock);
2848                 list_del_init(&cqr->blocklist);
2849                 __dasd_cleanup_cqr(cqr);
2850                 spin_unlock_irq(&dq->lock);
2851         }
2852
2853         spin_lock_irq(&block->queue_lock);
2854         /* Now check if the head of the ccw queue needs to be started. */
2855         __dasd_block_start_head(block);
2856         spin_unlock_irq(&block->queue_lock);
2857
2858         if (waitqueue_active(&shutdown_waitq))
2859                 wake_up(&shutdown_waitq);
2860         dasd_put_device(block->base);
2861 }
2862
2863 static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
2864 {
2865         wake_up(&dasd_flush_wq);
2866 }
2867
2868 /*
2869  * Requeue a request back to the block request queue
2870  * only works for block requests
2871  */
2872 static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
2873 {
2874         struct dasd_block *block = cqr->block;
2875         struct request *req;
2876
2877         if (!block)
2878                 return -EINVAL;
2879         spin_lock_irq(&cqr->dq->lock);
2880         req = (struct request *) cqr->callback_data;
2881         blk_mq_requeue_request(req, false);
2882         spin_unlock_irq(&cqr->dq->lock);
2883
2884         return 0;
2885 }
2886
2887 /*
2888  * Go through all request on the dasd_block request queue, cancel them
2889  * on the respective dasd_device, and return them to the generic
2890  * block layer.
2891  */
2892 static int dasd_flush_block_queue(struct dasd_block *block)
2893 {
2894         struct dasd_ccw_req *cqr, *n;
2895         int rc, i;
2896         struct list_head flush_queue;
2897         unsigned long flags;
2898
2899         INIT_LIST_HEAD(&flush_queue);
2900         spin_lock_bh(&block->queue_lock);
2901         rc = 0;
2902 restart:
2903         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
2904                 /* if this request currently owned by a dasd_device cancel it */
2905                 if (cqr->status >= DASD_CQR_QUEUED)
2906                         rc = dasd_cancel_req(cqr);
2907                 if (rc < 0)
2908                         break;
2909                 /* Rechain request (including erp chain) so it won't be
2910                  * touched by the dasd_block_tasklet anymore.
2911                  * Replace the callback so we notice when the request
2912                  * is returned from the dasd_device layer.
2913                  */
2914                 cqr->callback = _dasd_wake_block_flush_cb;
2915                 for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
2916                         list_move_tail(&cqr->blocklist, &flush_queue);
2917                 if (i > 1)
2918                         /* moved more than one request - need to restart */
2919                         goto restart;
2920         }
2921         spin_unlock_bh(&block->queue_lock);
2922         /* Now call the callback function of flushed requests */
2923 restart_cb:
2924         list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
2925                 wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
2926                 /* Process finished ERP request. */
2927                 if (cqr->refers) {
2928                         spin_lock_bh(&block->queue_lock);
2929                         __dasd_process_erp(block->base, cqr);
2930                         spin_unlock_bh(&block->queue_lock);
2931                         /* restart list_for_xx loop since dasd_process_erp
2932                          * might remove multiple elements */
2933                         goto restart_cb;
2934                 }
2935                 /* call the callback function */
2936                 spin_lock_irqsave(&cqr->dq->lock, flags);
2937                 cqr->endclk = get_tod_clock();
2938                 list_del_init(&cqr->blocklist);
2939                 __dasd_cleanup_cqr(cqr);
2940                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
2941         }
2942         return rc;
2943 }
2944
2945 /*
2946  * Schedules a call to dasd_tasklet over the device tasklet.
2947  */
2948 void dasd_schedule_block_bh(struct dasd_block *block)
2949 {
2950         /* Protect against rescheduling. */
2951         if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
2952                 return;
2953         /* life cycle of block is bound to it's base device */
2954         dasd_get_device(block->base);
2955         tasklet_hi_schedule(&block->tasklet);
2956 }
2957 EXPORT_SYMBOL(dasd_schedule_block_bh);
2958
2959
2960 /*
2961  * SECTION: external block device operations
2962  * (request queue handling, open, release, etc.)
2963  */
2964
2965 /*
2966  * Dasd request queue function. Called from ll_rw_blk.c
2967  */
2968 static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
2969                                     const struct blk_mq_queue_data *qd)
2970 {
2971         struct dasd_block *block = hctx->queue->queuedata;
2972         struct dasd_queue *dq = hctx->driver_data;
2973         struct request *req = qd->rq;
2974         struct dasd_device *basedev;
2975         struct dasd_ccw_req *cqr;
2976         blk_status_t rc = BLK_STS_OK;
2977
2978         basedev = block->base;
2979         spin_lock_irq(&dq->lock);
2980         if (basedev->state < DASD_STATE_READY) {
2981                 DBF_DEV_EVENT(DBF_ERR, basedev,
2982                               "device not ready for request %p", req);
2983                 rc = BLK_STS_IOERR;
2984                 goto out;
2985         }
2986
2987         /*
2988          * if device is stopped do not fetch new requests
2989          * except failfast is active which will let requests fail
2990          * immediately in __dasd_block_start_head()
2991          */
2992         if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
2993                 DBF_DEV_EVENT(DBF_ERR, basedev,
2994                               "device stopped request %p", req);
2995                 rc = BLK_STS_RESOURCE;
2996                 goto out;
2997         }
2998
2999         if (basedev->features & DASD_FEATURE_READONLY &&
3000             rq_data_dir(req) == WRITE) {
3001                 DBF_DEV_EVENT(DBF_ERR, basedev,
3002                               "Rejecting write request %p", req);
3003                 rc = BLK_STS_IOERR;
3004                 goto out;
3005         }
3006
3007         if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
3008             (basedev->features & DASD_FEATURE_FAILFAST ||
3009              blk_noretry_request(req))) {
3010                 DBF_DEV_EVENT(DBF_ERR, basedev,
3011                               "Rejecting failfast request %p", req);
3012                 rc = BLK_STS_IOERR;
3013                 goto out;
3014         }
3015
3016         cqr = basedev->discipline->build_cp(basedev, block, req);
3017         if (IS_ERR(cqr)) {
3018                 if (PTR_ERR(cqr) == -EBUSY ||
3019                     PTR_ERR(cqr) == -ENOMEM ||
3020                     PTR_ERR(cqr) == -EAGAIN) {
3021                         rc = BLK_STS_RESOURCE;
3022                         goto out;
3023                 }
3024                 DBF_DEV_EVENT(DBF_ERR, basedev,
3025                               "CCW creation failed (rc=%ld) on request %p",
3026                               PTR_ERR(cqr), req);
3027                 rc = BLK_STS_IOERR;
3028                 goto out;
3029         }
3030         /*
3031          *  Note: callback is set to dasd_return_cqr_cb in
3032          * __dasd_block_start_head to cover erp requests as well
3033          */
3034         cqr->callback_data = req;
3035         cqr->status = DASD_CQR_FILLED;
3036         cqr->dq = dq;
3037         req->completion_data = cqr;
3038         blk_mq_start_request(req);
3039         spin_lock(&block->queue_lock);
3040         list_add_tail(&cqr->blocklist, &block->ccw_queue);
3041         INIT_LIST_HEAD(&cqr->devlist);
3042         dasd_profile_start(block, cqr, req);
3043         dasd_schedule_block_bh(block);
3044         spin_unlock(&block->queue_lock);
3045
3046 out:
3047         spin_unlock_irq(&dq->lock);
3048         return rc;
3049 }
3050
3051 /*
3052  * Block timeout callback, called from the block layer
3053  *
3054  * Return values:
3055  * BLK_EH_RESET_TIMER if the request should be left running
3056  * BLK_EH_NOT_HANDLED if the request is handled or terminated
3057  *                    by the driver.
3058  */
3059 enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
3060 {
3061         struct dasd_ccw_req *cqr = req->completion_data;
3062         struct dasd_block *block = req->q->queuedata;
3063         struct dasd_device *device;
3064         unsigned long flags;
3065         int rc = 0;
3066
3067         if (!cqr)
3068                 return BLK_EH_NOT_HANDLED;
3069
3070         spin_lock_irqsave(&cqr->dq->lock, flags);
3071         device = cqr->startdev ? cqr->startdev : block->base;
3072         if (!device->blk_timeout) {
3073                 spin_unlock_irqrestore(&cqr->dq->lock, flags);
3074                 return BLK_EH_RESET_TIMER;
3075         }
3076         DBF_DEV_EVENT(DBF_WARNING, device,
3077                       " dasd_times_out cqr %p status %x",
3078                       cqr, cqr->status);
3079
3080         spin_lock(&block->queue_lock);
3081         spin_lock(get_ccwdev_lock(device->cdev));
3082         cqr->retries = -1;
3083         cqr->intrc = -ETIMEDOUT;
3084         if (cqr->status >= DASD_CQR_QUEUED) {
3085                 spin_unlock(get_ccwdev_lock(device->cdev));
3086                 rc = dasd_cancel_req(cqr);
3087         } else if (cqr->status == DASD_CQR_FILLED ||
3088                    cqr->status == DASD_CQR_NEED_ERP) {
3089                 cqr->status = DASD_CQR_TERMINATED;
3090                 spin_unlock(get_ccwdev_lock(device->cdev));
3091         } else if (cqr->status == DASD_CQR_IN_ERP) {
3092                 struct dasd_ccw_req *searchcqr, *nextcqr, *tmpcqr;
3093
3094                 list_for_each_entry_safe(searchcqr, nextcqr,
3095                                          &block->ccw_queue, blocklist) {
3096                         tmpcqr = searchcqr;
3097                         while (tmpcqr->refers)
3098                                 tmpcqr = tmpcqr->refers;
3099                         if (tmpcqr != cqr)
3100                                 continue;
3101                         /* searchcqr is an ERP request for cqr */
3102                         searchcqr->retries = -1;
3103                         searchcqr->intrc = -ETIMEDOUT;
3104                         if (searchcqr->status >= DASD_CQR_QUEUED) {
3105                                 spin_unlock(get_ccwdev_lock(device->cdev));
3106                                 rc = dasd_cancel_req(searchcqr);
3107                                 spin_lock(get_ccwdev_lock(device->cdev));
3108                         } else if ((searchcqr->status == DASD_CQR_FILLED) ||
3109                                    (searchcqr->status == DASD_CQR_NEED_ERP)) {
3110                                 searchcqr->status = DASD_CQR_TERMINATED;
3111                                 rc = 0;
3112                         } else if (searchcqr->status == DASD_CQR_IN_ERP) {
3113                                 /*
3114                                  * Shouldn't happen; most recent ERP
3115                                  * request is at the front of queue
3116                                  */
3117                                 continue;
3118                         }
3119                         break;
3120                 }
3121                 spin_unlock(get_ccwdev_lock(device->cdev));
3122         }
3123         dasd_schedule_block_bh(block);
3124         spin_unlock(&block->queue_lock);
3125         spin_unlock_irqrestore(&cqr->dq->lock, flags);
3126
3127         return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
3128 }
3129
3130 static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
3131                           unsigned int idx)
3132 {
3133         struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
3134
3135         if (!dq)
3136                 return -ENOMEM;
3137
3138         spin_lock_init(&dq->lock);
3139         hctx->driver_data = dq;
3140
3141         return 0;
3142 }
3143
3144 static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
3145 {
3146         kfree(hctx->driver_data);
3147         hctx->driver_data = NULL;
3148 }
3149
3150 static void dasd_request_done(struct request *req)
3151 {
3152         blk_mq_end_request(req, 0);
3153         blk_mq_run_hw_queues(req->q, true);
3154 }
3155
3156 static struct blk_mq_ops dasd_mq_ops = {
3157         .queue_rq = do_dasd_request,
3158         .complete = dasd_request_done,
3159         .timeout = dasd_times_out,
3160         .init_hctx = dasd_init_hctx,
3161         .exit_hctx = dasd_exit_hctx,
3162 };
3163
3164 /*
3165  * Allocate and initialize request queue and default I/O scheduler.
3166  */
3167 static int dasd_alloc_queue(struct dasd_block *block)
3168 {
3169         int rc;
3170
3171         block->tag_set.ops = &dasd_mq_ops;
3172         block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES;
3173         block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV;
3174         block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
3175
3176         rc = blk_mq_alloc_tag_set(&block->tag_set);
3177         if (rc)
3178                 return rc;
3179
3180         block->request_queue = blk_mq_init_queue(&block->tag_set);
3181         if (IS_ERR(block->request_queue))
3182                 return PTR_ERR(block->request_queue);
3183
3184         block->request_queue->queuedata = block;
3185
3186         return 0;
3187 }
3188
3189 /*
3190  * Allocate and initialize request queue.
3191  */
3192 static void dasd_setup_queue(struct dasd_block *block)
3193 {
3194         unsigned int logical_block_size = block->bp_block;
3195         struct request_queue *q = block->request_queue;
3196         unsigned int max_bytes, max_discard_sectors;
3197         int max;
3198
3199         if (block->base->features & DASD_FEATURE_USERAW) {
3200                 /*
3201                  * the max_blocks value for raw_track access is 256
3202                  * it is higher than the native ECKD value because we
3203                  * only need one ccw per track
3204                  * so the max_hw_sectors are
3205                  * 2048 x 512B = 1024kB = 16 tracks
3206                  */
3207                 max = 2048;
3208         } else {
3209                 max = block->base->discipline->max_blocks << block->s2b_shift;
3210         }
3211         blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
3212         q->limits.max_dev_sectors = max;
3213         blk_queue_logical_block_size(q, logical_block_size);
3214         blk_queue_max_hw_sectors(q, max);
3215         blk_queue_max_segments(q, USHRT_MAX);
3216         /* with page sized segments we can translate each segement into
3217          * one idaw/tidaw
3218          */
3219         blk_queue_max_segment_size(q, PAGE_SIZE);
3220         blk_queue_segment_boundary(q, PAGE_SIZE - 1);
3221
3222         /* Only activate blocklayer discard support for devices that support it */
3223         if (block->base->features & DASD_FEATURE_DISCARD) {
3224                 q->limits.discard_granularity = logical_block_size;
3225                 q->limits.discard_alignment = PAGE_SIZE;
3226
3227                 /* Calculate max_discard_sectors and make it PAGE aligned */
3228                 max_bytes = USHRT_MAX * logical_block_size;
3229                 max_bytes = ALIGN(max_bytes, PAGE_SIZE) - PAGE_SIZE;
3230                 max_discard_sectors = max_bytes / logical_block_size;
3231
3232                 blk_queue_max_discard_sectors(q, max_discard_sectors);
3233                 blk_queue_max_write_zeroes_sectors(q, max_discard_sectors);
3234                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
3235         }
3236 }
3237
3238 /*
3239  * Deactivate and free request queue.
3240  */
3241 static void dasd_free_queue(struct dasd_block *block)
3242 {
3243         if (block->request_queue) {
3244                 blk_cleanup_queue(block->request_queue);
3245                 blk_mq_free_tag_set(&block->tag_set);
3246                 block->request_queue = NULL;
3247         }
3248 }
3249
3250 static int dasd_open(struct block_device *bdev, fmode_t mode)
3251 {
3252         struct dasd_device *base;
3253         int rc;
3254
3255         base = dasd_device_from_gendisk(bdev->bd_disk);
3256         if (!base)
3257                 return -ENODEV;
3258
3259         atomic_inc(&base->block->open_count);
3260         if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
3261                 rc = -ENODEV;
3262                 goto unlock;
3263         }
3264
3265         if (!try_module_get(base->discipline->owner)) {
3266                 rc = -EINVAL;
3267                 goto unlock;
3268         }
3269
3270         if (dasd_probeonly) {
3271                 dev_info(&base->cdev->dev,
3272                          "Accessing the DASD failed because it is in "
3273                          "probeonly mode\n");
3274                 rc = -EPERM;
3275                 goto out;
3276         }
3277
3278         if (base->state <= DASD_STATE_BASIC) {
3279                 DBF_DEV_EVENT(DBF_ERR, base, " %s",
3280                               " Cannot open unrecognized device");
3281                 rc = -ENODEV;
3282                 goto out;
3283         }
3284
3285         if ((mode & FMODE_WRITE) &&
3286             (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
3287              (base->features & DASD_FEATURE_READONLY))) {
3288                 rc = -EROFS;
3289                 goto out;
3290         }
3291
3292         dasd_put_device(base);
3293         return 0;
3294
3295 out:
3296         module_put(base->discipline->owner);
3297 unlock:
3298         atomic_dec(&base->block->open_count);
3299         dasd_put_device(base);
3300         return rc;
3301 }
3302
3303 static void dasd_release(struct gendisk *disk, fmode_t mode)
3304 {
3305         struct dasd_device *base = dasd_device_from_gendisk(disk);
3306         if (base) {
3307                 atomic_dec(&base->block->open_count);
3308                 module_put(base->discipline->owner);
3309                 dasd_put_device(base);
3310         }
3311 }
3312
3313 /*
3314  * Return disk geometry.
3315  */
3316 static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
3317 {
3318         struct dasd_device *base;
3319
3320         base = dasd_device_from_gendisk(bdev->bd_disk);
3321         if (!base)
3322                 return -ENODEV;
3323
3324         if (!base->discipline ||
3325             !base->discipline->fill_geometry) {
3326                 dasd_put_device(base);
3327                 return -EINVAL;
3328         }
3329         base->discipline->fill_geometry(base->block, geo);
3330         geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
3331         dasd_put_device(base);
3332         return 0;
3333 }
3334
3335 const struct block_device_operations
3336 dasd_device_operations = {
3337         .owner          = THIS_MODULE,
3338         .open           = dasd_open,
3339         .release        = dasd_release,
3340         .ioctl          = dasd_ioctl,
3341         .compat_ioctl   = dasd_ioctl,
3342         .getgeo         = dasd_getgeo,
3343 };
3344
3345 /*******************************************************************************
3346  * end of block device operations
3347  */
3348
3349 static void
3350 dasd_exit(void)
3351 {
3352 #ifdef CONFIG_PROC_FS
3353         dasd_proc_exit();
3354 #endif