md/bcache: convert comma to semicolon
[linux-2.6-microblaze.git] / drivers / s390 / cio / device.c
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  *  bus driver for ccw devices
4  *
5  *    Copyright IBM Corp. 2002, 2008
6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
9  */
10
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
13
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/spinlock.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/list.h>
21 #include <linux/device.h>
22 #include <linux/workqueue.h>
23 #include <linux/delay.h>
24 #include <linux/timer.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/sched/signal.h>
27 #include <linux/dma-mapping.h>
28
29 #include <asm/ccwdev.h>
30 #include <asm/cio.h>
31 #include <asm/param.h>          /* HZ */
32 #include <asm/cmb.h>
33 #include <asm/isc.h>
34
35 #include "chp.h"
36 #include "cio.h"
37 #include "cio_debug.h"
38 #include "css.h"
39 #include "device.h"
40 #include "ioasm.h"
41 #include "io_sch.h"
42 #include "blacklist.h"
43 #include "chsc.h"
44
45 static struct timer_list recovery_timer;
46 static DEFINE_SPINLOCK(recovery_lock);
47 static int recovery_phase;
48 static const unsigned long recovery_delay[] = { 3, 30, 300 };
49
50 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
51 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
52 static struct bus_type ccw_bus_type;
53
54 /******************* bus type handling ***********************/
55
56 /* The Linux driver model distinguishes between a bus type and
57  * the bus itself. Of course we only have one channel
58  * subsystem driver and one channel system per machine, but
59  * we still use the abstraction. T.R. says it's a good idea. */
60 static int
61 ccw_bus_match (struct device * dev, struct device_driver * drv)
62 {
63         struct ccw_device *cdev = to_ccwdev(dev);
64         struct ccw_driver *cdrv = to_ccwdrv(drv);
65         const struct ccw_device_id *ids = cdrv->ids, *found;
66
67         if (!ids)
68                 return 0;
69
70         found = ccw_device_id_match(ids, &cdev->id);
71         if (!found)
72                 return 0;
73
74         cdev->id.driver_info = found->driver_info;
75
76         return 1;
77 }
78
79 /* Store modalias string delimited by prefix/suffix string into buffer with
80  * specified size. Return length of resulting string (excluding trailing '\0')
81  * even if string doesn't fit buffer (snprintf semantics). */
82 static int snprint_alias(char *buf, size_t size,
83                          struct ccw_device_id *id, const char *suffix)
84 {
85         int len;
86
87         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
88         if (len > size)
89                 return len;
90         buf += len;
91         size -= len;
92
93         if (id->dev_type != 0)
94                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
95                                 id->dev_model, suffix);
96         else
97                 len += snprintf(buf, size, "dtdm%s", suffix);
98
99         return len;
100 }
101
102 /* Set up environment variables for ccw device uevent. Return 0 on success,
103  * non-zero otherwise. */
104 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
105 {
106         struct ccw_device *cdev = to_ccwdev(dev);
107         struct ccw_device_id *id = &(cdev->id);
108         int ret;
109         char modalias_buf[30];
110
111         /* CU_TYPE= */
112         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
113         if (ret)
114                 return ret;
115
116         /* CU_MODEL= */
117         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
118         if (ret)
119                 return ret;
120
121         /* The next two can be zero, that's ok for us */
122         /* DEV_TYPE= */
123         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
124         if (ret)
125                 return ret;
126
127         /* DEV_MODEL= */
128         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
129         if (ret)
130                 return ret;
131
132         /* MODALIAS=  */
133         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
134         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
135         return ret;
136 }
137
138 static void io_subchannel_irq(struct subchannel *);
139 static int io_subchannel_probe(struct subchannel *);
140 static int io_subchannel_remove(struct subchannel *);
141 static void io_subchannel_shutdown(struct subchannel *);
142 static int io_subchannel_sch_event(struct subchannel *, int);
143 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
144                                    int);
145 static void recovery_func(struct timer_list *unused);
146
147 static struct css_device_id io_subchannel_ids[] = {
148         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
149         { /* end of list */ },
150 };
151
152 static int io_subchannel_settle(void)
153 {
154         int ret;
155
156         ret = wait_event_interruptible(ccw_device_init_wq,
157                                 atomic_read(&ccw_device_init_count) == 0);
158         if (ret)
159                 return -EINTR;
160         flush_workqueue(cio_work_q);
161         return 0;
162 }
163
164 static struct css_driver io_subchannel_driver = {
165         .drv = {
166                 .owner = THIS_MODULE,
167                 .name = "io_subchannel",
168         },
169         .subchannel_type = io_subchannel_ids,
170         .irq = io_subchannel_irq,
171         .sch_event = io_subchannel_sch_event,
172         .chp_event = io_subchannel_chp_event,
173         .probe = io_subchannel_probe,
174         .remove = io_subchannel_remove,
175         .shutdown = io_subchannel_shutdown,
176         .settle = io_subchannel_settle,
177 };
178
179 int __init io_subchannel_init(void)
180 {
181         int ret;
182
183         timer_setup(&recovery_timer, recovery_func, 0);
184         ret = bus_register(&ccw_bus_type);
185         if (ret)
186                 return ret;
187         ret = css_driver_register(&io_subchannel_driver);
188         if (ret)
189                 bus_unregister(&ccw_bus_type);
190
191         return ret;
192 }
193
194
195 /************************ device handling **************************/
196
197 static ssize_t
198 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
199 {
200         struct ccw_device *cdev = to_ccwdev(dev);
201         struct ccw_device_id *id = &(cdev->id);
202
203         if (id->dev_type != 0)
204                 return sprintf(buf, "%04x/%02x\n",
205                                 id->dev_type, id->dev_model);
206         else
207                 return sprintf(buf, "n/a\n");
208 }
209
210 static ssize_t
211 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
212 {
213         struct ccw_device *cdev = to_ccwdev(dev);
214         struct ccw_device_id *id = &(cdev->id);
215
216         return sprintf(buf, "%04x/%02x\n",
217                        id->cu_type, id->cu_model);
218 }
219
220 static ssize_t
221 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
222 {
223         struct ccw_device *cdev = to_ccwdev(dev);
224         struct ccw_device_id *id = &(cdev->id);
225         int len;
226
227         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
228
229         return len > PAGE_SIZE ? PAGE_SIZE : len;
230 }
231
232 static ssize_t
233 online_show (struct device *dev, struct device_attribute *attr, char *buf)
234 {
235         struct ccw_device *cdev = to_ccwdev(dev);
236
237         return sprintf(buf, cdev->online ? "1\n" : "0\n");
238 }
239
240 int ccw_device_is_orphan(struct ccw_device *cdev)
241 {
242         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
243 }
244
245 static void ccw_device_unregister(struct ccw_device *cdev)
246 {
247         if (device_is_registered(&cdev->dev)) {
248                 /* Undo device_add(). */
249                 device_del(&cdev->dev);
250         }
251         if (cdev->private->flags.initialized) {
252                 cdev->private->flags.initialized = 0;
253                 /* Release reference from device_initialize(). */
254                 put_device(&cdev->dev);
255         }
256 }
257
258 static void io_subchannel_quiesce(struct subchannel *);
259
260 /**
261  * ccw_device_set_offline() - disable a ccw device for I/O
262  * @cdev: target ccw device
263  *
264  * This function calls the driver's set_offline() function for @cdev, if
265  * given, and then disables @cdev.
266  * Returns:
267  *   %0 on success and a negative error value on failure.
268  * Context:
269  *  enabled, ccw device lock not held
270  */
271 int ccw_device_set_offline(struct ccw_device *cdev)
272 {
273         struct subchannel *sch;
274         int ret, state;
275
276         if (!cdev)
277                 return -ENODEV;
278         if (!cdev->online || !cdev->drv)
279                 return -EINVAL;
280
281         if (cdev->drv->set_offline) {
282                 ret = cdev->drv->set_offline(cdev);
283                 if (ret != 0)
284                         return ret;
285         }
286         spin_lock_irq(cdev->ccwlock);
287         sch = to_subchannel(cdev->dev.parent);
288         cdev->online = 0;
289         /* Wait until a final state or DISCONNECTED is reached */
290         while (!dev_fsm_final_state(cdev) &&
291                cdev->private->state != DEV_STATE_DISCONNECTED) {
292                 spin_unlock_irq(cdev->ccwlock);
293                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
294                            cdev->private->state == DEV_STATE_DISCONNECTED));
295                 spin_lock_irq(cdev->ccwlock);
296         }
297         do {
298                 ret = ccw_device_offline(cdev);
299                 if (!ret)
300                         break;
301                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
302                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
303                               cdev->private->dev_id.devno);
304                 if (ret != -EBUSY)
305                         goto error;
306                 state = cdev->private->state;
307                 spin_unlock_irq(cdev->ccwlock);
308                 io_subchannel_quiesce(sch);
309                 spin_lock_irq(cdev->ccwlock);
310                 cdev->private->state = state;
311         } while (ret == -EBUSY);
312         spin_unlock_irq(cdev->ccwlock);
313         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
314                    cdev->private->state == DEV_STATE_DISCONNECTED));
315         /* Inform the user if set offline failed. */
316         if (cdev->private->state == DEV_STATE_BOXED) {
317                 pr_warn("%s: The device entered boxed state while being set offline\n",
318                         dev_name(&cdev->dev));
319         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
320                 pr_warn("%s: The device stopped operating while being set offline\n",
321                         dev_name(&cdev->dev));
322         }
323         /* Give up reference from ccw_device_set_online(). */
324         put_device(&cdev->dev);
325         return 0;
326
327 error:
328         cdev->private->state = DEV_STATE_OFFLINE;
329         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
330         spin_unlock_irq(cdev->ccwlock);
331         /* Give up reference from ccw_device_set_online(). */
332         put_device(&cdev->dev);
333         return -ENODEV;
334 }
335
336 /**
337  * ccw_device_set_online() - enable a ccw device for I/O
338  * @cdev: target ccw device
339  *
340  * This function first enables @cdev and then calls the driver's set_online()
341  * function for @cdev, if given. If set_online() returns an error, @cdev is
342  * disabled again.
343  * Returns:
344  *   %0 on success and a negative error value on failure.
345  * Context:
346  *  enabled, ccw device lock not held
347  */
348 int ccw_device_set_online(struct ccw_device *cdev)
349 {
350         int ret;
351         int ret2;
352
353         if (!cdev)
354                 return -ENODEV;
355         if (cdev->online || !cdev->drv)
356                 return -EINVAL;
357         /* Hold on to an extra reference while device is online. */
358         if (!get_device(&cdev->dev))
359                 return -ENODEV;
360
361         spin_lock_irq(cdev->ccwlock);
362         ret = ccw_device_online(cdev);
363         spin_unlock_irq(cdev->ccwlock);
364         if (ret == 0)
365                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
366         else {
367                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
368                               "device 0.%x.%04x\n",
369                               ret, cdev->private->dev_id.ssid,
370                               cdev->private->dev_id.devno);
371                 /* Give up online reference since onlining failed. */
372                 put_device(&cdev->dev);
373                 return ret;
374         }
375         spin_lock_irq(cdev->ccwlock);
376         /* Check if online processing was successful */
377         if ((cdev->private->state != DEV_STATE_ONLINE) &&
378             (cdev->private->state != DEV_STATE_W4SENSE)) {
379                 spin_unlock_irq(cdev->ccwlock);
380                 /* Inform the user that set online failed. */
381                 if (cdev->private->state == DEV_STATE_BOXED) {
382                         pr_warn("%s: Setting the device online failed because it is boxed\n",
383                                 dev_name(&cdev->dev));
384                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
385                         pr_warn("%s: Setting the device online failed because it is not operational\n",
386                                 dev_name(&cdev->dev));
387                 }
388                 /* Give up online reference since onlining failed. */
389                 put_device(&cdev->dev);
390                 return -ENODEV;
391         }
392         spin_unlock_irq(cdev->ccwlock);
393         if (cdev->drv->set_online)
394                 ret = cdev->drv->set_online(cdev);
395         if (ret)
396                 goto rollback;
397
398         spin_lock_irq(cdev->ccwlock);
399         cdev->online = 1;
400         spin_unlock_irq(cdev->ccwlock);
401         return 0;
402
403 rollback:
404         spin_lock_irq(cdev->ccwlock);
405         /* Wait until a final state or DISCONNECTED is reached */
406         while (!dev_fsm_final_state(cdev) &&
407                cdev->private->state != DEV_STATE_DISCONNECTED) {
408                 spin_unlock_irq(cdev->ccwlock);
409                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
410                            cdev->private->state == DEV_STATE_DISCONNECTED));
411                 spin_lock_irq(cdev->ccwlock);
412         }
413         ret2 = ccw_device_offline(cdev);
414         if (ret2)
415                 goto error;
416         spin_unlock_irq(cdev->ccwlock);
417         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
418                    cdev->private->state == DEV_STATE_DISCONNECTED));
419         /* Give up online reference since onlining failed. */
420         put_device(&cdev->dev);
421         return ret;
422
423 error:
424         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
425                       "device 0.%x.%04x\n",
426                       ret2, cdev->private->dev_id.ssid,
427                       cdev->private->dev_id.devno);
428         cdev->private->state = DEV_STATE_OFFLINE;
429         spin_unlock_irq(cdev->ccwlock);
430         /* Give up online reference since onlining failed. */
431         put_device(&cdev->dev);
432         return ret;
433 }
434
435 static int online_store_handle_offline(struct ccw_device *cdev)
436 {
437         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
438                 spin_lock_irq(cdev->ccwlock);
439                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
440                 spin_unlock_irq(cdev->ccwlock);
441                 return 0;
442         }
443         if (cdev->drv && cdev->drv->set_offline)
444                 return ccw_device_set_offline(cdev);
445         return -EINVAL;
446 }
447
448 static int online_store_recog_and_online(struct ccw_device *cdev)
449 {
450         /* Do device recognition, if needed. */
451         if (cdev->private->state == DEV_STATE_BOXED) {
452                 spin_lock_irq(cdev->ccwlock);
453                 ccw_device_recognition(cdev);
454                 spin_unlock_irq(cdev->ccwlock);
455                 wait_event(cdev->private->wait_q,
456                            cdev->private->flags.recog_done);
457                 if (cdev->private->state != DEV_STATE_OFFLINE)
458                         /* recognition failed */
459                         return -EAGAIN;
460         }
461         if (cdev->drv && cdev->drv->set_online)
462                 return ccw_device_set_online(cdev);
463         return -EINVAL;
464 }
465
466 static int online_store_handle_online(struct ccw_device *cdev, int force)
467 {
468         int ret;
469
470         ret = online_store_recog_and_online(cdev);
471         if (ret && !force)
472                 return ret;
473         if (force && cdev->private->state == DEV_STATE_BOXED) {
474                 ret = ccw_device_stlck(cdev);
475                 if (ret)
476                         return ret;
477                 if (cdev->id.cu_type == 0)
478                         cdev->private->state = DEV_STATE_NOT_OPER;
479                 ret = online_store_recog_and_online(cdev);
480                 if (ret)
481                         return ret;
482         }
483         return 0;
484 }
485
486 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
487                              const char *buf, size_t count)
488 {
489         struct ccw_device *cdev = to_ccwdev(dev);
490         int force, ret;
491         unsigned long i;
492
493         /* Prevent conflict between multiple on-/offline processing requests. */
494         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
495                 return -EAGAIN;
496         /* Prevent conflict between internal I/Os and on-/offline processing. */
497         if (!dev_fsm_final_state(cdev) &&
498             cdev->private->state != DEV_STATE_DISCONNECTED) {
499                 ret = -EAGAIN;
500                 goto out;
501         }
502         /* Prevent conflict between pending work and on-/offline processing.*/
503         if (work_pending(&cdev->private->todo_work)) {
504                 ret = -EAGAIN;
505                 goto out;
506         }
507         if (!strncmp(buf, "force\n", count)) {
508                 force = 1;
509                 i = 1;
510                 ret = 0;
511         } else {
512                 force = 0;
513                 ret = kstrtoul(buf, 16, &i);
514         }
515         if (ret)
516                 goto out;
517
518         device_lock(dev);
519         switch (i) {
520         case 0:
521                 ret = online_store_handle_offline(cdev);
522                 break;
523         case 1:
524                 ret = online_store_handle_online(cdev, force);
525                 break;
526         default:
527                 ret = -EINVAL;
528         }
529         device_unlock(dev);
530
531 out:
532         atomic_set(&cdev->private->onoff, 0);
533         return (ret < 0) ? ret : count;
534 }
535
536 static ssize_t
537 available_show (struct device *dev, struct device_attribute *attr, char *buf)
538 {
539         struct ccw_device *cdev = to_ccwdev(dev);
540         struct subchannel *sch;
541
542         if (ccw_device_is_orphan(cdev))
543                 return sprintf(buf, "no device\n");
544         switch (cdev->private->state) {
545         case DEV_STATE_BOXED:
546                 return sprintf(buf, "boxed\n");
547         case DEV_STATE_DISCONNECTED:
548         case DEV_STATE_DISCONNECTED_SENSE_ID:
549         case DEV_STATE_NOT_OPER:
550                 sch = to_subchannel(dev->parent);
551                 if (!sch->lpm)
552                         return sprintf(buf, "no path\n");
553                 else
554                         return sprintf(buf, "no device\n");
555         default:
556                 /* All other states considered fine. */
557                 return sprintf(buf, "good\n");
558         }
559 }
560
561 static ssize_t
562 initiate_logging(struct device *dev, struct device_attribute *attr,
563                  const char *buf, size_t count)
564 {
565         struct subchannel *sch = to_subchannel(dev);
566         int rc;
567
568         rc = chsc_siosl(sch->schid);
569         if (rc < 0) {
570                 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
571                         sch->schid.ssid, sch->schid.sch_no, rc);
572                 return rc;
573         }
574         pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
575                   sch->schid.ssid, sch->schid.sch_no);
576         return count;
577 }
578
579 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
580                         char *buf)
581 {
582         struct subchannel *sch = to_subchannel(dev);
583
584         return sprintf(buf, "%02x\n", sch->vpm);
585 }
586
587 static DEVICE_ATTR_RO(devtype);
588 static DEVICE_ATTR_RO(cutype);
589 static DEVICE_ATTR_RO(modalias);
590 static DEVICE_ATTR_RW(online);
591 static DEVICE_ATTR(availability, 0444, available_show, NULL);
592 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
593 static DEVICE_ATTR_RO(vpm);
594
595 static struct attribute *io_subchannel_attrs[] = {
596         &dev_attr_logging.attr,
597         &dev_attr_vpm.attr,
598         NULL,
599 };
600
601 static const struct attribute_group io_subchannel_attr_group = {
602         .attrs = io_subchannel_attrs,
603 };
604
605 static struct attribute * ccwdev_attrs[] = {
606         &dev_attr_devtype.attr,
607         &dev_attr_cutype.attr,
608         &dev_attr_modalias.attr,
609         &dev_attr_online.attr,
610         &dev_attr_cmb_enable.attr,
611         &dev_attr_availability.attr,
612         NULL,
613 };
614
615 static const struct attribute_group ccwdev_attr_group = {
616         .attrs = ccwdev_attrs,
617 };
618
619 static const struct attribute_group *ccwdev_attr_groups[] = {
620         &ccwdev_attr_group,
621         NULL,
622 };
623
624 static int ccw_device_add(struct ccw_device *cdev)
625 {
626         struct device *dev = &cdev->dev;
627
628         dev->bus = &ccw_bus_type;
629         return device_add(dev);
630 }
631
632 static int match_dev_id(struct device *dev, const void *data)
633 {
634         struct ccw_device *cdev = to_ccwdev(dev);
635         struct ccw_dev_id *dev_id = (void *)data;
636
637         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
638 }
639
640 /**
641  * get_ccwdev_by_dev_id() - obtain device from a ccw device id
642  * @dev_id: id of the device to be searched
643  *
644  * This function searches all devices attached to the ccw bus for a device
645  * matching @dev_id.
646  * Returns:
647  *  If a device is found its reference count is increased and returned;
648  *  else %NULL is returned.
649  */
650 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
651 {
652         struct device *dev;
653
654         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
655
656         return dev ? to_ccwdev(dev) : NULL;
657 }
658 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
659
660 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
661 {
662         int ret;
663
664         if (device_is_registered(&cdev->dev)) {
665                 device_release_driver(&cdev->dev);
666                 ret = device_attach(&cdev->dev);
667                 WARN_ON(ret == -ENODEV);
668         }
669 }
670
671 static void
672 ccw_device_release(struct device *dev)
673 {
674         struct ccw_device *cdev;
675
676         cdev = to_ccwdev(dev);
677         cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
678                         sizeof(*cdev->private->dma_area));
679         cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
680         /* Release reference of parent subchannel. */
681         put_device(cdev->dev.parent);
682         kfree(cdev->private);
683         kfree(cdev);
684 }
685
686 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
687 {
688         struct ccw_device *cdev;
689         struct gen_pool *dma_pool;
690
691         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
692         if (!cdev)
693                 goto err_cdev;
694         cdev->private = kzalloc(sizeof(struct ccw_device_private),
695                                 GFP_KERNEL | GFP_DMA);
696         if (!cdev->private)
697                 goto err_priv;
698         cdev->dev.coherent_dma_mask = sch->dev.coherent_dma_mask;
699         cdev->dev.dma_mask = sch->dev.dma_mask;
700         dma_pool = cio_gp_dma_create(&cdev->dev, 1);
701         if (!dma_pool)
702                 goto err_dma_pool;
703         cdev->private->dma_pool = dma_pool;
704         cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
705                                         sizeof(*cdev->private->dma_area));
706         if (!cdev->private->dma_area)
707                 goto err_dma_area;
708         return cdev;
709 err_dma_area:
710         cio_gp_dma_destroy(dma_pool, &cdev->dev);
711 err_dma_pool:
712         kfree(cdev->private);
713 err_priv:
714         kfree(cdev);
715 err_cdev:
716         return ERR_PTR(-ENOMEM);
717 }
718
719 static void ccw_device_todo(struct work_struct *work);
720
721 static int io_subchannel_initialize_dev(struct subchannel *sch,
722                                         struct ccw_device *cdev)
723 {
724         struct ccw_device_private *priv = cdev->private;
725         int ret;
726
727         priv->cdev = cdev;
728         priv->int_class = IRQIO_CIO;
729         priv->state = DEV_STATE_NOT_OPER;
730         priv->dev_id.devno = sch->schib.pmcw.dev;
731         priv->dev_id.ssid = sch->schid.ssid;
732
733         INIT_WORK(&priv->todo_work, ccw_device_todo);
734         INIT_LIST_HEAD(&priv->cmb_list);
735         init_waitqueue_head(&priv->wait_q);
736         timer_setup(&priv->timer, ccw_device_timeout, 0);
737
738         atomic_set(&priv->onoff, 0);
739         cdev->ccwlock = sch->lock;
740         cdev->dev.parent = &sch->dev;
741         cdev->dev.release = ccw_device_release;
742         cdev->dev.groups = ccwdev_attr_groups;
743         /* Do first half of device_register. */
744         device_initialize(&cdev->dev);
745         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
746                            cdev->private->dev_id.devno);
747         if (ret)
748                 goto out_put;
749         if (!get_device(&sch->dev)) {
750                 ret = -ENODEV;
751                 goto out_put;
752         }
753         priv->flags.initialized = 1;
754         spin_lock_irq(sch->lock);
755         sch_set_cdev(sch, cdev);
756         spin_unlock_irq(sch->lock);
757         return 0;
758
759 out_put:
760         /* Release reference from device_initialize(). */
761         put_device(&cdev->dev);
762         return ret;
763 }
764
765 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
766 {
767         struct ccw_device *cdev;
768         int ret;
769
770         cdev = io_subchannel_allocate_dev(sch);
771         if (!IS_ERR(cdev)) {
772                 ret = io_subchannel_initialize_dev(sch, cdev);
773                 if (ret)
774                         cdev = ERR_PTR(ret);
775         }
776         return cdev;
777 }
778
779 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
780
781 static void sch_create_and_recog_new_device(struct subchannel *sch)
782 {
783         struct ccw_device *cdev;
784
785         /* Need to allocate a new ccw device. */
786         cdev = io_subchannel_create_ccwdev(sch);
787         if (IS_ERR(cdev)) {
788                 /* OK, we did everything we could... */
789                 css_sch_device_unregister(sch);
790                 return;
791         }
792         /* Start recognition for the new ccw device. */
793         io_subchannel_recog(cdev, sch);
794 }
795
796 /*
797  * Register recognized device.
798  */
799 static void io_subchannel_register(struct ccw_device *cdev)
800 {
801         struct subchannel *sch;
802         int ret, adjust_init_count = 1;
803         unsigned long flags;
804
805         sch = to_subchannel(cdev->dev.parent);
806         /*
807          * Check if subchannel is still registered. It may have become
808          * unregistered if a machine check hit us after finishing
809          * device recognition but before the register work could be
810          * queued.
811          */
812         if (!device_is_registered(&sch->dev))
813                 goto out_err;
814         css_update_ssd_info(sch);
815         /*
816          * io_subchannel_register() will also be called after device
817          * recognition has been done for a boxed device (which will already
818          * be registered). We need to reprobe since we may now have sense id
819          * information.
820          */
821         if (device_is_registered(&cdev->dev)) {
822                 if (!cdev->drv) {
823                         ret = device_reprobe(&cdev->dev);
824                         if (ret)
825                                 /* We can't do much here. */
826                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
827                                               " %d for 0.%x.%04x\n", ret,
828                                               cdev->private->dev_id.ssid,
829                                               cdev->private->dev_id.devno);
830                 }
831                 adjust_init_count = 0;
832                 goto out;
833         }
834         /*
835          * Now we know this subchannel will stay, we can throw
836          * our delayed uevent.
837          */
838         if (dev_get_uevent_suppress(&sch->dev)) {
839                 dev_set_uevent_suppress(&sch->dev, 0);
840                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
841         }
842         /* make it known to the system */
843         ret = ccw_device_add(cdev);
844         if (ret) {
845                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
846                               cdev->private->dev_id.ssid,
847                               cdev->private->dev_id.devno, ret);
848                 spin_lock_irqsave(sch->lock, flags);
849                 sch_set_cdev(sch, NULL);
850                 spin_unlock_irqrestore(sch->lock, flags);
851                 /* Release initial device reference. */
852                 put_device(&cdev->dev);
853                 goto out_err;
854         }
855 out:
856         cdev->private->flags.recog_done = 1;
857         wake_up(&cdev->private->wait_q);
858 out_err:
859         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
860                 wake_up(&ccw_device_init_wq);
861 }
862
863 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
864 {
865         struct subchannel *sch;
866
867         /* Get subchannel reference for local processing. */
868         if (!get_device(cdev->dev.parent))
869                 return;
870         sch = to_subchannel(cdev->dev.parent);
871         css_sch_device_unregister(sch);
872         /* Release subchannel reference for local processing. */
873         put_device(&sch->dev);
874 }
875
876 /*
877  * subchannel recognition done. Called from the state machine.
878  */
879 void
880 io_subchannel_recog_done(struct ccw_device *cdev)
881 {
882         if (css_init_done == 0) {
883                 cdev->private->flags.recog_done = 1;
884                 return;
885         }
886         switch (cdev->private->state) {
887         case DEV_STATE_BOXED:
888                 /* Device did not respond in time. */
889         case DEV_STATE_NOT_OPER:
890                 cdev->private->flags.recog_done = 1;
891                 /* Remove device found not operational. */
892                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
893                 if (atomic_dec_and_test(&ccw_device_init_count))
894                         wake_up(&ccw_device_init_wq);
895                 break;
896         case DEV_STATE_OFFLINE:
897                 /*
898                  * We can't register the device in interrupt context so
899                  * we schedule a work item.
900                  */
901                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
902                 break;
903         }
904 }
905
906 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
907 {
908         /* Increase counter of devices currently in recognition. */
909         atomic_inc(&ccw_device_init_count);
910
911         /* Start async. device sensing. */
912         spin_lock_irq(sch->lock);
913         ccw_device_recognition(cdev);
914         spin_unlock_irq(sch->lock);
915 }
916
917 static int ccw_device_move_to_sch(struct ccw_device *cdev,
918                                   struct subchannel *sch)
919 {
920         struct subchannel *old_sch;
921         int rc, old_enabled = 0;
922
923         old_sch = to_subchannel(cdev->dev.parent);
924         /* Obtain child reference for new parent. */
925         if (!get_device(&sch->dev))
926                 return -ENODEV;
927
928         if (!sch_is_pseudo_sch(old_sch)) {
929                 spin_lock_irq(old_sch->lock);
930                 old_enabled = old_sch->schib.pmcw.ena;
931                 rc = 0;
932                 if (old_enabled)
933                         rc = cio_disable_subchannel(old_sch);
934                 spin_unlock_irq(old_sch->lock);
935                 if (rc == -EBUSY) {
936                         /* Release child reference for new parent. */
937                         put_device(&sch->dev);
938                         return rc;
939                 }
940         }
941
942         mutex_lock(&sch->reg_mutex);
943         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
944         mutex_unlock(&sch->reg_mutex);
945         if (rc) {
946                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
947                               cdev->private->dev_id.ssid,
948                               cdev->private->dev_id.devno, sch->schid.ssid,
949                               sch->schib.pmcw.dev, rc);
950                 if (old_enabled) {
951                         /* Try to reenable the old subchannel. */
952                         spin_lock_irq(old_sch->lock);
953                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
954                         spin_unlock_irq(old_sch->lock);
955                 }
956                 /* Release child reference for new parent. */
957                 put_device(&sch->dev);
958                 return rc;
959         }
960         /* Clean up old subchannel. */
961         if (!sch_is_pseudo_sch(old_sch)) {
962                 spin_lock_irq(old_sch->lock);
963                 sch_set_cdev(old_sch, NULL);
964                 spin_unlock_irq(old_sch->lock);
965                 css_schedule_eval(old_sch->schid);
966         }
967         /* Release child reference for old parent. */
968         put_device(&old_sch->dev);
969         /* Initialize new subchannel. */
970         spin_lock_irq(sch->lock);
971         cdev->ccwlock = sch->lock;
972         if (!sch_is_pseudo_sch(sch))
973                 sch_set_cdev(sch, cdev);
974         spin_unlock_irq(sch->lock);
975         if (!sch_is_pseudo_sch(sch))
976                 css_update_ssd_info(sch);
977         return 0;
978 }
979
980 static int ccw_device_move_to_orph(struct ccw_device *cdev)
981 {
982         struct subchannel *sch = to_subchannel(cdev->dev.parent);
983         struct channel_subsystem *css = to_css(sch->dev.parent);
984
985         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
986 }
987
988 static void io_subchannel_irq(struct subchannel *sch)
989 {
990         struct ccw_device *cdev;
991
992         cdev = sch_get_cdev(sch);
993
994         CIO_TRACE_EVENT(6, "IRQ");
995         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
996         if (cdev)
997                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
998         else
999                 inc_irq_stat(IRQIO_CIO);
1000 }
1001
1002 void io_subchannel_init_config(struct subchannel *sch)
1003 {
1004         memset(&sch->config, 0, sizeof(sch->config));
1005         sch->config.csense = 1;
1006 }
1007
1008 static void io_subchannel_init_fields(struct subchannel *sch)
1009 {
1010         if (cio_is_console(sch->schid))
1011                 sch->opm = 0xff;
1012         else
1013                 sch->opm = chp_get_sch_opm(sch);
1014         sch->lpm = sch->schib.pmcw.pam & sch->opm;
1015         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1016
1017         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1018                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
1019                       sch->schib.pmcw.dev, sch->schid.ssid,
1020                       sch->schid.sch_no, sch->schib.pmcw.pim,
1021                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1022
1023         io_subchannel_init_config(sch);
1024 }
1025
1026 /*
1027  * Note: We always return 0 so that we bind to the device even on error.
1028  * This is needed so that our remove function is called on unregister.
1029  */
1030 static int io_subchannel_probe(struct subchannel *sch)
1031 {
1032         struct io_subchannel_private *io_priv;
1033         struct ccw_device *cdev;
1034         int rc;
1035
1036         if (cio_is_console(sch->schid)) {
1037                 rc = sysfs_create_group(&sch->dev.kobj,
1038                                         &io_subchannel_attr_group);
1039                 if (rc)
1040                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1041                                       "attributes for subchannel "
1042                                       "0.%x.%04x (rc=%d)\n",
1043                                       sch->schid.ssid, sch->schid.sch_no, rc);
1044                 /*
1045                  * The console subchannel already has an associated ccw_device.
1046                  * Throw the delayed uevent for the subchannel, register
1047                  * the ccw_device and exit.
1048                  */
1049                 if (dev_get_uevent_suppress(&sch->dev)) {
1050                         /* should always be the case for the console */
1051                         dev_set_uevent_suppress(&sch->dev, 0);
1052                         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1053                 }
1054                 cdev = sch_get_cdev(sch);
1055                 rc = ccw_device_add(cdev);
1056                 if (rc) {
1057                         /* Release online reference. */
1058                         put_device(&cdev->dev);
1059                         goto out_schedule;
1060                 }
1061                 if (atomic_dec_and_test(&ccw_device_init_count))
1062                         wake_up(&ccw_device_init_wq);
1063                 return 0;
1064         }
1065         io_subchannel_init_fields(sch);
1066         rc = cio_commit_config(sch);
1067         if (rc)
1068                 goto out_schedule;
1069         rc = sysfs_create_group(&sch->dev.kobj,
1070                                 &io_subchannel_attr_group);
1071         if (rc)
1072                 goto out_schedule;
1073         /* Allocate I/O subchannel private data. */
1074         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1075         if (!io_priv)
1076                 goto out_schedule;
1077
1078         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1079                                 sizeof(*io_priv->dma_area),
1080                                 &io_priv->dma_area_dma, GFP_KERNEL);
1081         if (!io_priv->dma_area) {
1082                 kfree(io_priv);
1083                 goto out_schedule;
1084         }
1085
1086         set_io_private(sch, io_priv);
1087         css_schedule_eval(sch->schid);
1088         return 0;
1089
1090 out_schedule:
1091         spin_lock_irq(sch->lock);
1092         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1093         spin_unlock_irq(sch->lock);
1094         return 0;
1095 }
1096
1097 static int io_subchannel_remove(struct subchannel *sch)
1098 {
1099         struct io_subchannel_private *io_priv = to_io_private(sch);
1100         struct ccw_device *cdev;
1101
1102         cdev = sch_get_cdev(sch);
1103         if (!cdev)
1104                 goto out_free;
1105
1106         ccw_device_unregister(cdev);
1107         spin_lock_irq(sch->lock);
1108         sch_set_cdev(sch, NULL);
1109         set_io_private(sch, NULL);
1110         spin_unlock_irq(sch->lock);
1111 out_free:
1112         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1113                           io_priv->dma_area, io_priv->dma_area_dma);
1114         kfree(io_priv);
1115         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1116         return 0;
1117 }
1118
1119 static void io_subchannel_verify(struct subchannel *sch)
1120 {
1121         struct ccw_device *cdev;
1122
1123         cdev = sch_get_cdev(sch);
1124         if (cdev)
1125                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1126 }
1127
1128 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1129 {
1130         struct ccw_device *cdev;
1131
1132         cdev = sch_get_cdev(sch);
1133         if (!cdev)
1134                 return;
1135         if (cio_update_schib(sch))
1136                 goto err;
1137         /* Check for I/O on path. */
1138         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1139                 goto out;
1140         if (cdev->private->state == DEV_STATE_ONLINE) {
1141                 ccw_device_kill_io(cdev);
1142                 goto out;
1143         }
1144         if (cio_clear(sch))
1145                 goto err;
1146 out:
1147         /* Trigger path verification. */
1148         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1149         return;
1150
1151 err:
1152         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1153 }
1154
1155 static int io_subchannel_chp_event(struct subchannel *sch,
1156                                    struct chp_link *link, int event)
1157 {
1158         struct ccw_device *cdev = sch_get_cdev(sch);
1159         int mask, chpid, valid_bit;
1160         int path_event[8];
1161
1162         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1163         if (!mask)
1164                 return 0;
1165         switch (event) {
1166         case CHP_VARY_OFF:
1167                 sch->opm &= ~mask;
1168                 sch->lpm &= ~mask;
1169                 if (cdev)
1170                         cdev->private->path_gone_mask |= mask;
1171                 io_subchannel_terminate_path(sch, mask);
1172                 break;
1173         case CHP_VARY_ON:
1174                 sch->opm |= mask;
1175                 sch->lpm |= mask;
1176                 if (cdev)
1177                         cdev->private->path_new_mask |= mask;
1178                 io_subchannel_verify(sch);
1179                 break;
1180         case CHP_OFFLINE:
1181                 if (cio_update_schib(sch))
1182                         return -ENODEV;
1183                 if (cdev)
1184                         cdev->private->path_gone_mask |= mask;
1185                 io_subchannel_terminate_path(sch, mask);
1186                 break;
1187         case CHP_ONLINE:
1188                 if (cio_update_schib(sch))
1189                         return -ENODEV;
1190                 sch->lpm |= mask & sch->opm;
1191                 if (cdev)
1192                         cdev->private->path_new_mask |= mask;
1193                 io_subchannel_verify(sch);
1194                 break;
1195         case CHP_FCES_EVENT:
1196                 /* Forward Endpoint Security event */
1197                 for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1198                                 valid_bit >>= 1) {
1199                         if (mask & valid_bit)
1200                                 path_event[chpid] = PE_PATH_FCES_EVENT;
1201                         else
1202                                 path_event[chpid] = PE_NONE;
1203                 }
1204                 if (cdev)
1205                         cdev->drv->path_event(cdev, path_event);
1206                 break;
1207         }
1208         return 0;
1209 }
1210
1211 static void io_subchannel_quiesce(struct subchannel *sch)
1212 {
1213         struct ccw_device *cdev;
1214         int ret;
1215
1216         spin_lock_irq(sch->lock);
1217         cdev = sch_get_cdev(sch);
1218         if (cio_is_console(sch->schid))
1219                 goto out_unlock;
1220         if (!sch->schib.pmcw.ena)
1221                 goto out_unlock;
1222         ret = cio_disable_subchannel(sch);
1223         if (ret != -EBUSY)
1224                 goto out_unlock;
1225         if (cdev->handler)
1226                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1227         while (ret == -EBUSY) {
1228                 cdev->private->state = DEV_STATE_QUIESCE;
1229                 cdev->private->iretry = 255;
1230                 ret = ccw_device_cancel_halt_clear(cdev);
1231                 if (ret == -EBUSY) {
1232                         ccw_device_set_timeout(cdev, HZ/10);
1233                         spin_unlock_irq(sch->lock);
1234                         wait_event(cdev->private->wait_q,
1235                                    cdev->private->state != DEV_STATE_QUIESCE);
1236                         spin_lock_irq(sch->lock);
1237                 }
1238                 ret = cio_disable_subchannel(sch);
1239         }
1240 out_unlock:
1241         spin_unlock_irq(sch->lock);
1242 }
1243
1244 static void io_subchannel_shutdown(struct subchannel *sch)
1245 {
1246         io_subchannel_quiesce(sch);
1247 }
1248
1249 static int device_is_disconnected(struct ccw_device *cdev)
1250 {
1251         if (!cdev)
1252                 return 0;
1253         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1254                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1255 }
1256
1257 static int recovery_check(struct device *dev, void *data)
1258 {
1259         struct ccw_device *cdev = to_ccwdev(dev);
1260         struct subchannel *sch;
1261         int *redo = data;
1262
1263         spin_lock_irq(cdev->ccwlock);
1264         switch (cdev->private->state) {
1265         case DEV_STATE_ONLINE:
1266                 sch = to_subchannel(cdev->dev.parent);
1267                 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1268                         break;
1269                 fallthrough;
1270         case DEV_STATE_DISCONNECTED:
1271                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1272                               cdev->private->dev_id.ssid,
1273                               cdev->private->dev_id.devno);
1274                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1275                 *redo = 1;
1276                 break;
1277         case DEV_STATE_DISCONNECTED_SENSE_ID:
1278                 *redo = 1;
1279                 break;
1280         }
1281         spin_unlock_irq(cdev->ccwlock);
1282
1283         return 0;
1284 }
1285
1286 static void recovery_work_func(struct work_struct *unused)
1287 {
1288         int redo = 0;
1289
1290         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1291         if (redo) {
1292                 spin_lock_irq(&recovery_lock);
1293                 if (!timer_pending(&recovery_timer)) {
1294                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1295                                 recovery_phase++;
1296                         mod_timer(&recovery_timer, jiffies +
1297                                   recovery_delay[recovery_phase] * HZ);
1298                 }
1299                 spin_unlock_irq(&recovery_lock);
1300         } else
1301                 CIO_MSG_EVENT(3, "recovery: end\n");
1302 }
1303
1304 static DECLARE_WORK(recovery_work, recovery_work_func);
1305
1306 static void recovery_func(struct timer_list *unused)
1307 {
1308         /*
1309          * We can't do our recovery in softirq context and it's not
1310          * performance critical, so we schedule it.
1311          */
1312         schedule_work(&recovery_work);
1313 }
1314
1315 void ccw_device_schedule_recovery(void)
1316 {
1317         unsigned long flags;
1318
1319         CIO_MSG_EVENT(3, "recovery: schedule\n");
1320         spin_lock_irqsave(&recovery_lock, flags);
1321         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1322                 recovery_phase = 0;
1323                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1324         }
1325         spin_unlock_irqrestore(&recovery_lock, flags);
1326 }
1327
1328 static int purge_fn(struct device *dev, void *data)
1329 {
1330         struct ccw_device *cdev = to_ccwdev(dev);
1331         struct ccw_dev_id *id = &cdev->private->dev_id;
1332
1333         spin_lock_irq(cdev->ccwlock);
1334         if (is_blacklisted(id->ssid, id->devno) &&
1335             (cdev->private->state == DEV_STATE_OFFLINE) &&
1336             (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1337                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1338                               id->devno);
1339                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1340                 atomic_set(&cdev->private->onoff, 0);
1341         }
1342         spin_unlock_irq(cdev->ccwlock);
1343         /* Abort loop in case of pending signal. */
1344         if (signal_pending(current))
1345                 return -EINTR;
1346
1347         return 0;
1348 }
1349
1350 /**
1351  * ccw_purge_blacklisted - purge unused, blacklisted devices
1352  *
1353  * Unregister all ccw devices that are offline and on the blacklist.
1354  */
1355 int ccw_purge_blacklisted(void)
1356 {
1357         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1358         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1359         return 0;
1360 }
1361
1362 void ccw_device_set_disconnected(struct ccw_device *cdev)
1363 {
1364         if (!cdev)
1365                 return;
1366         ccw_device_set_timeout(cdev, 0);
1367         cdev->private->flags.fake_irb = 0;
1368         cdev->private->state = DEV_STATE_DISCONNECTED;
1369         if (cdev->online)
1370                 ccw_device_schedule_recovery();
1371 }
1372
1373 void ccw_device_set_notoper(struct ccw_device *cdev)
1374 {
1375         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1376
1377         CIO_TRACE_EVENT(2, "notoper");
1378         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1379         ccw_device_set_timeout(cdev, 0);
1380         cio_disable_subchannel(sch);
1381         cdev->private->state = DEV_STATE_NOT_OPER;
1382 }
1383
1384 enum io_sch_action {
1385         IO_SCH_UNREG,
1386         IO_SCH_ORPH_UNREG,
1387         IO_SCH_ATTACH,
1388         IO_SCH_UNREG_ATTACH,
1389         IO_SCH_ORPH_ATTACH,
1390         IO_SCH_REPROBE,
1391         IO_SCH_VERIFY,
1392         IO_SCH_DISC,
1393         IO_SCH_NOP,
1394 };
1395
1396 static enum io_sch_action sch_get_action(struct subchannel *sch)
1397 {
1398         struct ccw_device *cdev;
1399
1400         cdev = sch_get_cdev(sch);
1401         if (cio_update_schib(sch)) {
1402                 /* Not operational. */
1403                 if (!cdev)
1404                         return IO_SCH_UNREG;
1405                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1406                         return IO_SCH_UNREG;
1407                 return IO_SCH_ORPH_UNREG;
1408         }
1409         /* Operational. */
1410         if (!cdev)
1411                 return IO_SCH_ATTACH;
1412         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1413                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1414                         return IO_SCH_UNREG_ATTACH;
1415                 return IO_SCH_ORPH_ATTACH;
1416         }
1417         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1418                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1419                         return IO_SCH_UNREG;
1420                 return IO_SCH_DISC;
1421         }
1422         if (device_is_disconnected(cdev))
1423                 return IO_SCH_REPROBE;
1424         if (cdev->online)
1425                 return IO_SCH_VERIFY;
1426         if (cdev->private->state == DEV_STATE_NOT_OPER)
1427                 return IO_SCH_UNREG_ATTACH;
1428         return IO_SCH_NOP;
1429 }
1430
1431 /**
1432  * io_subchannel_sch_event - process subchannel event
1433  * @sch: subchannel
1434  * @process: non-zero if function is called in process context
1435  *
1436  * An unspecified event occurred for this subchannel. Adjust data according
1437  * to the current operational state of the subchannel and device. Return
1438  * zero when the event has been handled sufficiently or -EAGAIN when this
1439  * function should be called again in process context.
1440  */
1441 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1442 {
1443         unsigned long flags;
1444         struct ccw_device *cdev;
1445         struct ccw_dev_id dev_id;
1446         enum io_sch_action action;
1447         int rc = -EAGAIN;
1448
1449         spin_lock_irqsave(sch->lock, flags);
1450         if (!device_is_registered(&sch->dev))
1451                 goto out_unlock;
1452         if (work_pending(&sch->todo_work))
1453                 goto out_unlock;
1454         cdev = sch_get_cdev(sch);
1455         if (cdev && work_pending(&cdev->private->todo_work))
1456                 goto out_unlock;
1457         action = sch_get_action(sch);
1458         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1459                       sch->schid.ssid, sch->schid.sch_no, process,
1460                       action);
1461         /* Perform immediate actions while holding the lock. */
1462         switch (action) {
1463         case IO_SCH_REPROBE:
1464                 /* Trigger device recognition. */
1465                 ccw_device_trigger_reprobe(cdev);
1466                 rc = 0;
1467                 goto out_unlock;
1468         case IO_SCH_VERIFY:
1469                 /* Trigger path verification. */
1470                 io_subchannel_verify(sch);
1471                 rc = 0;
1472                 goto out_unlock;
1473         case IO_SCH_DISC:
1474                 ccw_device_set_disconnected(cdev);
1475                 rc = 0;
1476                 goto out_unlock;
1477         case IO_SCH_ORPH_UNREG:
1478         case IO_SCH_ORPH_ATTACH:
1479                 ccw_device_set_disconnected(cdev);
1480                 break;
1481         case IO_SCH_UNREG_ATTACH:
1482         case IO_SCH_UNREG:
1483                 if (!cdev)
1484                         break;
1485                 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1486                         /*
1487                          * Note: delayed work triggered by this event
1488                          * and repeated calls to sch_event are synchronized
1489                          * by the above check for work_pending(cdev).
1490                          */
1491                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1492                 } else
1493                         ccw_device_set_notoper(cdev);
1494                 break;
1495         case IO_SCH_NOP:
1496                 rc = 0;
1497                 goto out_unlock;
1498         default:
1499                 break;
1500         }
1501         spin_unlock_irqrestore(sch->lock, flags);
1502         /* All other actions require process context. */
1503         if (!process)
1504                 goto out;
1505         /* Handle attached ccw device. */
1506         switch (action) {
1507         case IO_SCH_ORPH_UNREG:
1508         case IO_SCH_ORPH_ATTACH:
1509                 /* Move ccw device to orphanage. */
1510                 rc = ccw_device_move_to_orph(cdev);
1511                 if (rc)
1512                         goto out;
1513                 break;
1514         case IO_SCH_UNREG_ATTACH:
1515                 spin_lock_irqsave(sch->lock, flags);
1516                 sch_set_cdev(sch, NULL);
1517                 spin_unlock_irqrestore(sch->lock, flags);
1518                 /* Unregister ccw device. */
1519                 ccw_device_unregister(cdev);
1520                 break;
1521         default:
1522                 break;
1523         }
1524         /* Handle subchannel. */
1525         switch (action) {
1526         case IO_SCH_ORPH_UNREG:
1527         case IO_SCH_UNREG:
1528                 if (!cdev)
1529                         css_sch_device_unregister(sch);
1530                 break;
1531         case IO_SCH_ORPH_ATTACH:
1532         case IO_SCH_UNREG_ATTACH:
1533         case IO_SCH_ATTACH:
1534                 dev_id.ssid = sch->schid.ssid;
1535                 dev_id.devno = sch->schib.pmcw.dev;
1536                 cdev = get_ccwdev_by_dev_id(&dev_id);
1537                 if (!cdev) {
1538                         sch_create_and_recog_new_device(sch);
1539                         break;
1540                 }
1541                 rc = ccw_device_move_to_sch(cdev, sch);
1542                 if (rc) {
1543                         /* Release reference from get_ccwdev_by_dev_id() */
1544                         put_device(&cdev->dev);
1545                         goto out;
1546                 }
1547                 spin_lock_irqsave(sch->lock, flags);
1548                 ccw_device_trigger_reprobe(cdev);
1549                 spin_unlock_irqrestore(sch->lock, flags);
1550                 /* Release reference from get_ccwdev_by_dev_id() */
1551                 put_device(&cdev->dev);
1552                 break;
1553         default:
1554                 break;
1555         }
1556         return 0;
1557
1558 out_unlock:
1559         spin_unlock_irqrestore(sch->lock, flags);
1560 out:
1561         return rc;
1562 }
1563
1564 static void ccw_device_set_int_class(struct ccw_device *cdev)
1565 {
1566         struct ccw_driver *cdrv = cdev->drv;
1567
1568         /* Note: we interpret class 0 in this context as an uninitialized
1569          * field since it translates to a non-I/O interrupt class. */
1570         if (cdrv->int_class != 0)
1571                 cdev->private->int_class = cdrv->int_class;
1572         else
1573                 cdev->private->int_class = IRQIO_CIO;
1574 }
1575
1576 #ifdef CONFIG_CCW_CONSOLE
1577 int __init ccw_device_enable_console(struct ccw_device *cdev)
1578 {
1579         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1580         int rc;
1581
1582         if (!cdev->drv || !cdev->handler)
1583                 return -EINVAL;
1584
1585         io_subchannel_init_fields(sch);
1586         rc = cio_commit_config(sch);
1587         if (rc)
1588                 return rc;
1589         sch->driver = &io_subchannel_driver;
1590         io_subchannel_recog(cdev, sch);
1591         /* Now wait for the async. recognition to come to an end. */
1592         spin_lock_irq(cdev->ccwlock);
1593         while (!dev_fsm_final_state(cdev))
1594                 ccw_device_wait_idle(cdev);
1595
1596         /* Hold on to an extra reference while device is online. */
1597         get_device(&cdev->dev);
1598         rc = ccw_device_online(cdev);
1599         if (rc)
1600                 goto out_unlock;
1601
1602         while (!dev_fsm_final_state(cdev))
1603                 ccw_device_wait_idle(cdev);
1604
1605         if (cdev->private->state == DEV_STATE_ONLINE)
1606                 cdev->online = 1;
1607         else
1608                 rc = -EIO;
1609 out_unlock:
1610         spin_unlock_irq(cdev->ccwlock);
1611         if (rc) /* Give up online reference since onlining failed. */
1612                 put_device(&cdev->dev);
1613         return rc;
1614 }
1615
1616 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1617 {
1618         struct io_subchannel_private *io_priv;
1619         struct ccw_device *cdev;
1620         struct subchannel *sch;
1621
1622         sch = cio_probe_console();
1623         if (IS_ERR(sch))
1624                 return ERR_CAST(sch);
1625
1626         io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1627         if (!io_priv)
1628                 goto err_priv;
1629         io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1630                                 sizeof(*io_priv->dma_area),
1631                                 &io_priv->dma_area_dma, GFP_KERNEL);
1632         if (!io_priv->dma_area)
1633                 goto err_dma_area;
1634         set_io_private(sch, io_priv);
1635         cdev = io_subchannel_create_ccwdev(sch);
1636         if (IS_ERR(cdev)) {
1637                 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1638                                   io_priv->dma_area, io_priv->dma_area_dma);
1639                 set_io_private(sch, NULL);
1640                 put_device(&sch->dev);
1641                 kfree(io_priv);
1642                 return cdev;
1643         }
1644         cdev->drv = drv;
1645         ccw_device_set_int_class(cdev);
1646         return cdev;
1647
1648 err_dma_area:
1649         kfree(io_priv);
1650 err_priv:
1651         put_device(&sch->dev);
1652         return ERR_PTR(-ENOMEM);
1653 }
1654
1655 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1656 {
1657         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1658         struct io_subchannel_private *io_priv = to_io_private(sch);
1659
1660         set_io_private(sch, NULL);
1661         dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1662                           io_priv->dma_area, io_priv->dma_area_dma);
1663         put_device(&sch->dev);
1664         put_device(&cdev->dev);
1665         kfree(io_priv);
1666 }
1667
1668 /**
1669  * ccw_device_wait_idle() - busy wait for device to become idle
1670  * @cdev: ccw device
1671  *
1672  * Poll until activity control is zero, that is, no function or data
1673  * transfer is pending/active.
1674  * Called with device lock being held.
1675  */
1676 void ccw_device_wait_idle(struct ccw_device *cdev)
1677 {
1678         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1679
1680         while (1) {
1681                 cio_tsch(sch);
1682                 if (sch->schib.scsw.cmd.actl == 0)
1683                         break;
1684                 udelay_simple(100);
1685         }
1686 }
1687 #endif
1688
1689 /**
1690  * get_ccwdev_by_busid() - obtain device from a bus id
1691  * @cdrv: driver the device is owned by
1692  * @bus_id: bus id of the device to be searched
1693  *
1694  * This function searches all devices owned by @cdrv for a device with a bus
1695  * id matching @bus_id.
1696  * Returns:
1697  *  If a match is found, its reference count of the found device is increased
1698  *  and it is returned; else %NULL is returned.
1699  */
1700 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1701                                        const char *bus_id)
1702 {
1703         struct device *dev;
1704
1705         dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1706
1707         return dev ? to_ccwdev(dev) : NULL;
1708 }
1709
1710 /************************** device driver handling ************************/
1711
1712 /* This is the implementation of the ccw_driver class. The probe, remove
1713  * and release methods are initially very similar to the device_driver
1714  * implementations, with the difference that they have ccw_device
1715  * arguments.
1716  *
1717  * A ccw driver also contains the information that is needed for
1718  * device matching.
1719  */
1720 static int
1721 ccw_device_probe (struct device *dev)
1722 {
1723         struct ccw_device *cdev = to_ccwdev(dev);
1724         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1725         int ret;
1726
1727         cdev->drv = cdrv; /* to let the driver call _set_online */
1728         ccw_device_set_int_class(cdev);
1729         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1730         if (ret) {
1731                 cdev->drv = NULL;
1732                 cdev->private->int_class = IRQIO_CIO;
1733                 return ret;
1734         }
1735
1736         return 0;
1737 }
1738
1739 static int ccw_device_remove(struct device *dev)
1740 {
1741         struct ccw_device *cdev = to_ccwdev(dev);
1742         struct ccw_driver *cdrv = cdev->drv;
1743         struct subchannel *sch;
1744         int ret;
1745
1746         if (cdrv->remove)
1747                 cdrv->remove(cdev);
1748
1749         spin_lock_irq(cdev->ccwlock);
1750         if (cdev->online) {
1751                 cdev->online = 0;
1752                 ret = ccw_device_offline(cdev);
1753                 spin_unlock_irq(cdev->ccwlock);
1754                 if (ret == 0)
1755                         wait_event(cdev->private->wait_q,
1756                                    dev_fsm_final_state(cdev));
1757                 else
1758                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1759                                       "device 0.%x.%04x\n",
1760                                       ret, cdev->private->dev_id.ssid,
1761                                       cdev->private->dev_id.devno);
1762                 /* Give up reference obtained in ccw_device_set_online(). */
1763                 put_device(&cdev->dev);
1764                 spin_lock_irq(cdev->ccwlock);
1765         }
1766         ccw_device_set_timeout(cdev, 0);
1767         cdev->drv = NULL;
1768         cdev->private->int_class = IRQIO_CIO;
1769         sch = to_subchannel(cdev->dev.parent);
1770         spin_unlock_irq(cdev->ccwlock);
1771         io_subchannel_quiesce(sch);
1772         __disable_cmf(cdev);
1773
1774         return 0;
1775 }
1776
1777 static void ccw_device_shutdown(struct device *dev)
1778 {
1779         struct ccw_device *cdev;
1780
1781         cdev = to_ccwdev(dev);
1782         if (cdev->drv && cdev->drv->shutdown)
1783                 cdev->drv->shutdown(cdev);
1784         __disable_cmf(cdev);
1785 }
1786
1787 static struct bus_type ccw_bus_type = {
1788         .name   = "ccw",
1789         .match  = ccw_bus_match,
1790         .uevent = ccw_uevent,
1791         .probe  = ccw_device_probe,
1792         .remove = ccw_device_remove,
1793         .shutdown = ccw_device_shutdown,
1794 };
1795
1796 /**
1797  * ccw_driver_register() - register a ccw driver
1798  * @cdriver: driver to be registered
1799  *
1800  * This function is mainly a wrapper around driver_register().
1801  * Returns:
1802  *   %0 on success and a negative error value on failure.
1803  */
1804 int ccw_driver_register(struct ccw_driver *cdriver)
1805 {
1806         struct device_driver *drv = &cdriver->driver;
1807
1808         drv->bus = &ccw_bus_type;
1809
1810         return driver_register(drv);
1811 }
1812
1813 /**
1814  * ccw_driver_unregister() - deregister a ccw driver
1815  * @cdriver: driver to be deregistered
1816  *
1817  * This function is mainly a wrapper around driver_unregister().
1818  */
1819 void ccw_driver_unregister(struct ccw_driver *cdriver)
1820 {
1821         driver_unregister(&cdriver->driver);
1822 }
1823
1824 static void ccw_device_todo(struct work_struct *work)
1825 {
1826         struct ccw_device_private *priv;
1827         struct ccw_device *cdev;
1828         struct subchannel *sch;
1829         enum cdev_todo todo;
1830
1831         priv = container_of(work, struct ccw_device_private, todo_work);
1832         cdev = priv->cdev;
1833         sch = to_subchannel(cdev->dev.parent);
1834         /* Find out todo. */
1835         spin_lock_irq(cdev->ccwlock);
1836         todo = priv->todo;
1837         priv->todo = CDEV_TODO_NOTHING;
1838         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1839                       priv->dev_id.ssid, priv->dev_id.devno, todo);
1840         spin_unlock_irq(cdev->ccwlock);
1841         /* Perform todo. */
1842         switch (todo) {
1843         case CDEV_TODO_ENABLE_CMF:
1844                 cmf_reenable(cdev);
1845                 break;
1846         case CDEV_TODO_REBIND:
1847                 ccw_device_do_unbind_bind(cdev);
1848                 break;
1849         case CDEV_TODO_REGISTER:
1850                 io_subchannel_register(cdev);
1851                 break;
1852         case CDEV_TODO_UNREG_EVAL:
1853                 if (!sch_is_pseudo_sch(sch))
1854                         css_schedule_eval(sch->schid);
1855                 fallthrough;
1856         case CDEV_TODO_UNREG:
1857                 if (sch_is_pseudo_sch(sch))
1858                         ccw_device_unregister(cdev);
1859                 else
1860                         ccw_device_call_sch_unregister(cdev);
1861                 break;
1862         default:
1863                 break;
1864         }
1865         /* Release workqueue ref. */
1866         put_device(&cdev->dev);
1867 }
1868
1869 /**
1870  * ccw_device_sched_todo - schedule ccw device operation
1871  * @cdev: ccw device
1872  * @todo: todo
1873  *
1874  * Schedule the operation identified by @todo to be performed on the slow path
1875  * workqueue. Do nothing if another operation with higher priority is already
1876  * scheduled. Needs to be called with ccwdev lock held.
1877  */
1878 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1879 {
1880         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1881                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1882                       todo);
1883         if (cdev->private->todo >= todo)
1884                 return;
1885         cdev->private->todo = todo;
1886         /* Get workqueue ref. */
1887         if (!get_device(&cdev->dev))
1888                 return;
1889         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1890                 /* Already queued, release workqueue ref. */
1891                 put_device(&cdev->dev);
1892         }
1893 }
1894
1895 /**
1896  * ccw_device_siosl() - initiate logging
1897  * @cdev: ccw device
1898  *
1899  * This function is used to invoke model-dependent logging within the channel
1900  * subsystem.
1901  */
1902 int ccw_device_siosl(struct ccw_device *cdev)
1903 {
1904         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1905
1906         return chsc_siosl(sch->schid);
1907 }
1908 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1909
1910 EXPORT_SYMBOL(ccw_device_set_online);
1911 EXPORT_SYMBOL(ccw_device_set_offline);
1912 EXPORT_SYMBOL(ccw_driver_register);
1913 EXPORT_SYMBOL(ccw_driver_unregister);
1914 EXPORT_SYMBOL(get_ccwdev_by_busid);