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[linux-2.6] / drivers / s390 / cio / device.c
1 /*
2  *  drivers/s390/cio/device.c
3  *  bus driver for ccw devices
4  *
5  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
6  *                       IBM Corporation
7  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
8  *               Cornelia Huck (cornelia.huck@de.ibm.com)
9  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
10  */
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/spinlock.h>
14 #include <linux/errno.h>
15 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/list.h>
18 #include <linux/device.h>
19 #include <linux/workqueue.h>
20 #include <linux/timer.h>
21
22 #include <asm/ccwdev.h>
23 #include <asm/cio.h>
24 #include <asm/param.h>          /* HZ */
25 #include <asm/cmb.h>
26
27 #include "cio.h"
28 #include "cio_debug.h"
29 #include "css.h"
30 #include "device.h"
31 #include "ioasm.h"
32 #include "io_sch.h"
33
34 static struct timer_list recovery_timer;
35 static spinlock_t recovery_lock;
36 static int recovery_phase;
37 static const unsigned long recovery_delay[] = { 3, 30, 300 };
38
39 /******************* bus type handling ***********************/
40
41 /* The Linux driver model distinguishes between a bus type and
42  * the bus itself. Of course we only have one channel
43  * subsystem driver and one channel system per machine, but
44  * we still use the abstraction. T.R. says it's a good idea. */
45 static int
46 ccw_bus_match (struct device * dev, struct device_driver * drv)
47 {
48         struct ccw_device *cdev = to_ccwdev(dev);
49         struct ccw_driver *cdrv = to_ccwdrv(drv);
50         const struct ccw_device_id *ids = cdrv->ids, *found;
51
52         if (!ids)
53                 return 0;
54
55         found = ccw_device_id_match(ids, &cdev->id);
56         if (!found)
57                 return 0;
58
59         cdev->id.driver_info = found->driver_info;
60
61         return 1;
62 }
63
64 /* Store modalias string delimited by prefix/suffix string into buffer with
65  * specified size. Return length of resulting string (excluding trailing '\0')
66  * even if string doesn't fit buffer (snprintf semantics). */
67 static int snprint_alias(char *buf, size_t size,
68                          struct ccw_device_id *id, const char *suffix)
69 {
70         int len;
71
72         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
73         if (len > size)
74                 return len;
75         buf += len;
76         size -= len;
77
78         if (id->dev_type != 0)
79                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
80                                 id->dev_model, suffix);
81         else
82                 len += snprintf(buf, size, "dtdm%s", suffix);
83
84         return len;
85 }
86
87 /* Set up environment variables for ccw device uevent. Return 0 on success,
88  * non-zero otherwise. */
89 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
90 {
91         struct ccw_device *cdev = to_ccwdev(dev);
92         struct ccw_device_id *id = &(cdev->id);
93         int ret;
94         char modalias_buf[30];
95
96         /* CU_TYPE= */
97         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
98         if (ret)
99                 return ret;
100
101         /* CU_MODEL= */
102         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
103         if (ret)
104                 return ret;
105
106         /* The next two can be zero, that's ok for us */
107         /* DEV_TYPE= */
108         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
109         if (ret)
110                 return ret;
111
112         /* DEV_MODEL= */
113         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
114         if (ret)
115                 return ret;
116
117         /* MODALIAS=  */
118         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
119         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
120         return ret;
121 }
122
123 struct bus_type ccw_bus_type;
124
125 static void io_subchannel_irq(struct subchannel *);
126 static int io_subchannel_probe(struct subchannel *);
127 static int io_subchannel_remove(struct subchannel *);
128 static int io_subchannel_notify(struct subchannel *, int);
129 static void io_subchannel_verify(struct subchannel *);
130 static void io_subchannel_ioterm(struct subchannel *);
131 static void io_subchannel_shutdown(struct subchannel *);
132
133 static struct css_driver io_subchannel_driver = {
134         .owner = THIS_MODULE,
135         .subchannel_type = SUBCHANNEL_TYPE_IO,
136         .name = "io_subchannel",
137         .irq = io_subchannel_irq,
138         .notify = io_subchannel_notify,
139         .verify = io_subchannel_verify,
140         .termination = io_subchannel_ioterm,
141         .probe = io_subchannel_probe,
142         .remove = io_subchannel_remove,
143         .shutdown = io_subchannel_shutdown,
144 };
145
146 struct workqueue_struct *ccw_device_work;
147 struct workqueue_struct *ccw_device_notify_work;
148 wait_queue_head_t ccw_device_init_wq;
149 atomic_t ccw_device_init_count;
150
151 static void recovery_func(unsigned long data);
152
153 static int __init
154 init_ccw_bus_type (void)
155 {
156         int ret;
157
158         init_waitqueue_head(&ccw_device_init_wq);
159         atomic_set(&ccw_device_init_count, 0);
160         setup_timer(&recovery_timer, recovery_func, 0);
161
162         ccw_device_work = create_singlethread_workqueue("cio");
163         if (!ccw_device_work)
164                 return -ENOMEM; /* FIXME: better errno ? */
165         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
166         if (!ccw_device_notify_work) {
167                 ret = -ENOMEM; /* FIXME: better errno ? */
168                 goto out_err;
169         }
170         slow_path_wq = create_singlethread_workqueue("kslowcrw");
171         if (!slow_path_wq) {
172                 ret = -ENOMEM; /* FIXME: better errno ? */
173                 goto out_err;
174         }
175         if ((ret = bus_register (&ccw_bus_type)))
176                 goto out_err;
177
178         ret = css_driver_register(&io_subchannel_driver);
179         if (ret)
180                 goto out_err;
181
182         wait_event(ccw_device_init_wq,
183                    atomic_read(&ccw_device_init_count) == 0);
184         flush_workqueue(ccw_device_work);
185         return 0;
186 out_err:
187         if (ccw_device_work)
188                 destroy_workqueue(ccw_device_work);
189         if (ccw_device_notify_work)
190                 destroy_workqueue(ccw_device_notify_work);
191         if (slow_path_wq)
192                 destroy_workqueue(slow_path_wq);
193         return ret;
194 }
195
196 static void __exit
197 cleanup_ccw_bus_type (void)
198 {
199         css_driver_unregister(&io_subchannel_driver);
200         bus_unregister(&ccw_bus_type);
201         destroy_workqueue(ccw_device_notify_work);
202         destroy_workqueue(ccw_device_work);
203 }
204
205 subsys_initcall(init_ccw_bus_type);
206 module_exit(cleanup_ccw_bus_type);
207
208 /************************ device handling **************************/
209
210 /*
211  * A ccw_device has some interfaces in sysfs in addition to the
212  * standard ones.
213  * The following entries are designed to export the information which
214  * resided in 2.4 in /proc/subchannels. Subchannel and device number
215  * are obvious, so they don't have an entry :)
216  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
217  */
218 static ssize_t
219 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
220 {
221         struct subchannel *sch = to_subchannel(dev);
222         struct chsc_ssd_info *ssd = &sch->ssd_info;
223         ssize_t ret = 0;
224         int chp;
225         int mask;
226
227         for (chp = 0; chp < 8; chp++) {
228                 mask = 0x80 >> chp;
229                 if (ssd->path_mask & mask)
230                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
231                 else
232                         ret += sprintf(buf + ret, "00 ");
233         }
234         ret += sprintf (buf+ret, "\n");
235         return min((ssize_t)PAGE_SIZE, ret);
236 }
237
238 static ssize_t
239 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
240 {
241         struct subchannel *sch = to_subchannel(dev);
242         struct pmcw *pmcw = &sch->schib.pmcw;
243
244         return sprintf (buf, "%02x %02x %02x\n",
245                         pmcw->pim, pmcw->pam, pmcw->pom);
246 }
247
248 static ssize_t
249 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
250 {
251         struct ccw_device *cdev = to_ccwdev(dev);
252         struct ccw_device_id *id = &(cdev->id);
253
254         if (id->dev_type != 0)
255                 return sprintf(buf, "%04x/%02x\n",
256                                 id->dev_type, id->dev_model);
257         else
258                 return sprintf(buf, "n/a\n");
259 }
260
261 static ssize_t
262 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
263 {
264         struct ccw_device *cdev = to_ccwdev(dev);
265         struct ccw_device_id *id = &(cdev->id);
266
267         return sprintf(buf, "%04x/%02x\n",
268                        id->cu_type, id->cu_model);
269 }
270
271 static ssize_t
272 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
273 {
274         struct ccw_device *cdev = to_ccwdev(dev);
275         struct ccw_device_id *id = &(cdev->id);
276         int len;
277
278         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
279
280         return len > PAGE_SIZE ? PAGE_SIZE : len;
281 }
282
283 static ssize_t
284 online_show (struct device *dev, struct device_attribute *attr, char *buf)
285 {
286         struct ccw_device *cdev = to_ccwdev(dev);
287
288         return sprintf(buf, cdev->online ? "1\n" : "0\n");
289 }
290
291 int ccw_device_is_orphan(struct ccw_device *cdev)
292 {
293         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
294 }
295
296 static void ccw_device_unregister(struct ccw_device *cdev)
297 {
298         if (test_and_clear_bit(1, &cdev->private->registered))
299                 device_del(&cdev->dev);
300 }
301
302 static void ccw_device_remove_orphan_cb(struct device *dev)
303 {
304         struct ccw_device *cdev = to_ccwdev(dev);
305
306         ccw_device_unregister(cdev);
307         put_device(&cdev->dev);
308 }
309
310 static void ccw_device_remove_sch_cb(struct device *dev)
311 {
312         struct subchannel *sch;
313
314         sch = to_subchannel(dev);
315         css_sch_device_unregister(sch);
316         /* Reset intparm to zeroes. */
317         sch->schib.pmcw.intparm = 0;
318         cio_modify(sch);
319         put_device(&sch->dev);
320 }
321
322 static void
323 ccw_device_remove_disconnected(struct ccw_device *cdev)
324 {
325         unsigned long flags;
326         int rc;
327
328         /*
329          * Forced offline in disconnected state means
330          * 'throw away device'.
331          */
332         if (ccw_device_is_orphan(cdev)) {
333                 /*
334                  * Deregister ccw device.
335                  * Unfortunately, we cannot do this directly from the
336                  * attribute method.
337                  */
338                 spin_lock_irqsave(cdev->ccwlock, flags);
339                 cdev->private->state = DEV_STATE_NOT_OPER;
340                 spin_unlock_irqrestore(cdev->ccwlock, flags);
341                 rc = device_schedule_callback(&cdev->dev,
342                                               ccw_device_remove_orphan_cb);
343                 if (rc)
344                         CIO_MSG_EVENT(2, "Couldn't unregister orphan "
345                                       "0.%x.%04x\n",
346                                       cdev->private->dev_id.ssid,
347                                       cdev->private->dev_id.devno);
348                 return;
349         }
350         /* Deregister subchannel, which will kill the ccw device. */
351         rc = device_schedule_callback(cdev->dev.parent,
352                                       ccw_device_remove_sch_cb);
353         if (rc)
354                 CIO_MSG_EVENT(2, "Couldn't unregister disconnected device "
355                               "0.%x.%04x\n",
356                               cdev->private->dev_id.ssid,
357                               cdev->private->dev_id.devno);
358 }
359
360 /**
361  * ccw_device_set_offline() - disable a ccw device for I/O
362  * @cdev: target ccw device
363  *
364  * This function calls the driver's set_offline() function for @cdev, if
365  * given, and then disables @cdev.
366  * Returns:
367  *   %0 on success and a negative error value on failure.
368  * Context:
369  *  enabled, ccw device lock not held
370  */
371 int ccw_device_set_offline(struct ccw_device *cdev)
372 {
373         int ret;
374
375         if (!cdev)
376                 return -ENODEV;
377         if (!cdev->online || !cdev->drv)
378                 return -EINVAL;
379
380         if (cdev->drv->set_offline) {
381                 ret = cdev->drv->set_offline(cdev);
382                 if (ret != 0)
383                         return ret;
384         }
385         cdev->online = 0;
386         spin_lock_irq(cdev->ccwlock);
387         ret = ccw_device_offline(cdev);
388         if (ret == -ENODEV) {
389                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
390                         cdev->private->state = DEV_STATE_OFFLINE;
391                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
392                 }
393                 spin_unlock_irq(cdev->ccwlock);
394                 return ret;
395         }
396         spin_unlock_irq(cdev->ccwlock);
397         if (ret == 0)
398                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
399         else {
400                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
401                               "device 0.%x.%04x\n",
402                               ret, cdev->private->dev_id.ssid,
403                               cdev->private->dev_id.devno);
404                 cdev->online = 1;
405         }
406         return ret;
407 }
408
409 /**
410  * ccw_device_set_online() - enable a ccw device for I/O
411  * @cdev: target ccw device
412  *
413  * This function first enables @cdev and then calls the driver's set_online()
414  * function for @cdev, if given. If set_online() returns an error, @cdev is
415  * disabled again.
416  * Returns:
417  *   %0 on success and a negative error value on failure.
418  * Context:
419  *  enabled, ccw device lock not held
420  */
421 int ccw_device_set_online(struct ccw_device *cdev)
422 {
423         int ret;
424
425         if (!cdev)
426                 return -ENODEV;
427         if (cdev->online || !cdev->drv)
428                 return -EINVAL;
429
430         spin_lock_irq(cdev->ccwlock);
431         ret = ccw_device_online(cdev);
432         spin_unlock_irq(cdev->ccwlock);
433         if (ret == 0)
434                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
435         else {
436                 CIO_MSG_EVENT(2, "ccw_device_online returned %d, "
437                               "device 0.%x.%04x\n",
438                               ret, cdev->private->dev_id.ssid,
439                               cdev->private->dev_id.devno);
440                 return ret;
441         }
442         if (cdev->private->state != DEV_STATE_ONLINE)
443                 return -ENODEV;
444         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
445                 cdev->online = 1;
446                 return 0;
447         }
448         spin_lock_irq(cdev->ccwlock);
449         ret = ccw_device_offline(cdev);
450         spin_unlock_irq(cdev->ccwlock);
451         if (ret == 0)
452                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
453         else
454                 CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
455                               "device 0.%x.%04x\n",
456                               ret, cdev->private->dev_id.ssid,
457                               cdev->private->dev_id.devno);
458         return (ret == 0) ? -ENODEV : ret;
459 }
460
461 static void online_store_handle_offline(struct ccw_device *cdev)
462 {
463         if (cdev->private->state == DEV_STATE_DISCONNECTED)
464                 ccw_device_remove_disconnected(cdev);
465         else if (cdev->drv && cdev->drv->set_offline)
466                 ccw_device_set_offline(cdev);
467 }
468
469 static int online_store_recog_and_online(struct ccw_device *cdev)
470 {
471         int ret;
472
473         /* Do device recognition, if needed. */
474         if (cdev->id.cu_type == 0) {
475                 ret = ccw_device_recognition(cdev);
476                 if (ret) {
477                         CIO_MSG_EVENT(0, "Couldn't start recognition "
478                                       "for device 0.%x.%04x (ret=%d)\n",
479                                       cdev->private->dev_id.ssid,
480                                       cdev->private->dev_id.devno, ret);
481                         return ret;
482                 }
483                 wait_event(cdev->private->wait_q,
484                            cdev->private->flags.recog_done);
485         }
486         if (cdev->drv && cdev->drv->set_online)
487                 ccw_device_set_online(cdev);
488         return 0;
489 }
490 static void online_store_handle_online(struct ccw_device *cdev, int force)
491 {
492         int ret;
493
494         ret = online_store_recog_and_online(cdev);
495         if (ret)
496                 return;
497         if (force && cdev->private->state == DEV_STATE_BOXED) {
498                 ret = ccw_device_stlck(cdev);
499                 if (ret) {
500                         dev_warn(&cdev->dev,
501                                  "ccw_device_stlck returned %d!\n", ret);
502                         return;
503                 }
504                 if (cdev->id.cu_type == 0)
505                         cdev->private->state = DEV_STATE_NOT_OPER;
506                 online_store_recog_and_online(cdev);
507         }
508
509 }
510
511 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
512                              const char *buf, size_t count)
513 {
514         struct ccw_device *cdev = to_ccwdev(dev);
515         int i, force;
516         char *tmp;
517
518         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
519                 return -EAGAIN;
520
521         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
522                 atomic_set(&cdev->private->onoff, 0);
523                 return -EINVAL;
524         }
525         if (!strncmp(buf, "force\n", count)) {
526                 force = 1;
527                 i = 1;
528         } else {
529                 force = 0;
530                 i = simple_strtoul(buf, &tmp, 16);
531         }
532
533         switch (i) {
534         case 0:
535                 online_store_handle_offline(cdev);
536                 break;
537         case 1:
538                 online_store_handle_online(cdev, force);
539                 break;
540         default:
541                 count = -EINVAL;
542         }
543         if (cdev->drv)
544                 module_put(cdev->drv->owner);
545         atomic_set(&cdev->private->onoff, 0);
546         return count;
547 }
548
549 static ssize_t
550 available_show (struct device *dev, struct device_attribute *attr, char *buf)
551 {
552         struct ccw_device *cdev = to_ccwdev(dev);
553         struct subchannel *sch;
554
555         if (ccw_device_is_orphan(cdev))
556                 return sprintf(buf, "no device\n");
557         switch (cdev->private->state) {
558         case DEV_STATE_BOXED:
559                 return sprintf(buf, "boxed\n");
560         case DEV_STATE_DISCONNECTED:
561         case DEV_STATE_DISCONNECTED_SENSE_ID:
562         case DEV_STATE_NOT_OPER:
563                 sch = to_subchannel(dev->parent);
564                 if (!sch->lpm)
565                         return sprintf(buf, "no path\n");
566                 else
567                         return sprintf(buf, "no device\n");
568         default:
569                 /* All other states considered fine. */
570                 return sprintf(buf, "good\n");
571         }
572 }
573
574 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
575 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
576 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
577 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
578 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
579 static DEVICE_ATTR(online, 0644, online_show, online_store);
580 extern struct device_attribute dev_attr_cmb_enable;
581 static DEVICE_ATTR(availability, 0444, available_show, NULL);
582
583 static struct attribute * subch_attrs[] = {
584         &dev_attr_chpids.attr,
585         &dev_attr_pimpampom.attr,
586         NULL,
587 };
588
589 static struct attribute_group subch_attr_group = {
590         .attrs = subch_attrs,
591 };
592
593 struct attribute_group *subch_attr_groups[] = {
594         &subch_attr_group,
595         NULL,
596 };
597
598 static struct attribute * ccwdev_attrs[] = {
599         &dev_attr_devtype.attr,
600         &dev_attr_cutype.attr,
601         &dev_attr_modalias.attr,
602         &dev_attr_online.attr,
603         &dev_attr_cmb_enable.attr,
604         &dev_attr_availability.attr,
605         NULL,
606 };
607
608 static struct attribute_group ccwdev_attr_group = {
609         .attrs = ccwdev_attrs,
610 };
611
612 static struct attribute_group *ccwdev_attr_groups[] = {
613         &ccwdev_attr_group,
614         NULL,
615 };
616
617 /* this is a simple abstraction for device_register that sets the
618  * correct bus type and adds the bus specific files */
619 static int ccw_device_register(struct ccw_device *cdev)
620 {
621         struct device *dev = &cdev->dev;
622         int ret;
623
624         dev->bus = &ccw_bus_type;
625
626         if ((ret = device_add(dev)))
627                 return ret;
628
629         set_bit(1, &cdev->private->registered);
630         return ret;
631 }
632
633 struct match_data {
634         struct ccw_dev_id dev_id;
635         struct ccw_device * sibling;
636 };
637
638 static int
639 match_devno(struct device * dev, void * data)
640 {
641         struct match_data * d = data;
642         struct ccw_device * cdev;
643
644         cdev = to_ccwdev(dev);
645         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
646             !ccw_device_is_orphan(cdev) &&
647             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
648             (cdev != d->sibling))
649                 return 1;
650         return 0;
651 }
652
653 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
654                                                      struct ccw_device *sibling)
655 {
656         struct device *dev;
657         struct match_data data;
658
659         data.dev_id = *dev_id;
660         data.sibling = sibling;
661         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
662
663         return dev ? to_ccwdev(dev) : NULL;
664 }
665
666 static int match_orphan(struct device *dev, void *data)
667 {
668         struct ccw_dev_id *dev_id;
669         struct ccw_device *cdev;
670
671         dev_id = data;
672         cdev = to_ccwdev(dev);
673         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
674 }
675
676 static struct ccw_device *
677 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
678                               struct ccw_dev_id *dev_id)
679 {
680         struct device *dev;
681
682         dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
683                                 match_orphan);
684
685         return dev ? to_ccwdev(dev) : NULL;
686 }
687
688 static void
689 ccw_device_add_changed(struct work_struct *work)
690 {
691         struct ccw_device_private *priv;
692         struct ccw_device *cdev;
693
694         priv = container_of(work, struct ccw_device_private, kick_work);
695         cdev = priv->cdev;
696         if (device_add(&cdev->dev)) {
697                 put_device(&cdev->dev);
698                 return;
699         }
700         set_bit(1, &cdev->private->registered);
701 }
702
703 void ccw_device_do_unreg_rereg(struct work_struct *work)
704 {
705         struct ccw_device_private *priv;
706         struct ccw_device *cdev;
707         struct subchannel *sch;
708
709         priv = container_of(work, struct ccw_device_private, kick_work);
710         cdev = priv->cdev;
711         sch = to_subchannel(cdev->dev.parent);
712
713         ccw_device_unregister(cdev);
714         PREPARE_WORK(&cdev->private->kick_work,
715                      ccw_device_add_changed);
716         queue_work(ccw_device_work, &cdev->private->kick_work);
717 }
718
719 static void
720 ccw_device_release(struct device *dev)
721 {
722         struct ccw_device *cdev;
723
724         cdev = to_ccwdev(dev);
725         kfree(cdev->private);
726         kfree(cdev);
727 }
728
729 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
730 {
731         struct ccw_device *cdev;
732
733         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
734         if (cdev) {
735                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
736                                         GFP_KERNEL | GFP_DMA);
737                 if (cdev->private)
738                         return cdev;
739         }
740         kfree(cdev);
741         return ERR_PTR(-ENOMEM);
742 }
743
744 static int io_subchannel_initialize_dev(struct subchannel *sch,
745                                         struct ccw_device *cdev)
746 {
747         cdev->private->cdev = cdev;
748         atomic_set(&cdev->private->onoff, 0);
749         cdev->dev.parent = &sch->dev;
750         cdev->dev.release = ccw_device_release;
751         INIT_WORK(&cdev->private->kick_work, NULL);
752         cdev->dev.groups = ccwdev_attr_groups;
753         /* Do first half of device_register. */
754         device_initialize(&cdev->dev);
755         if (!get_device(&sch->dev)) {
756                 if (cdev->dev.release)
757                         cdev->dev.release(&cdev->dev);
758                 return -ENODEV;
759         }
760         return 0;
761 }
762
763 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
764 {
765         struct ccw_device *cdev;
766         int ret;
767
768         cdev = io_subchannel_allocate_dev(sch);
769         if (!IS_ERR(cdev)) {
770                 ret = io_subchannel_initialize_dev(sch, cdev);
771                 if (ret) {
772                         kfree(cdev);
773                         cdev = ERR_PTR(ret);
774                 }
775         }
776         return cdev;
777 }
778
779 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
780
781 static void sch_attach_device(struct subchannel *sch,
782                               struct ccw_device *cdev)
783 {
784         css_update_ssd_info(sch);
785         spin_lock_irq(sch->lock);
786         sch_set_cdev(sch, cdev);
787         cdev->private->schid = sch->schid;
788         cdev->ccwlock = sch->lock;
789         device_trigger_reprobe(sch);
790         spin_unlock_irq(sch->lock);
791 }
792
793 static void sch_attach_disconnected_device(struct subchannel *sch,
794                                            struct ccw_device *cdev)
795 {
796         struct subchannel *other_sch;
797         int ret;
798
799         other_sch = to_subchannel(get_device(cdev->dev.parent));
800         ret = device_move(&cdev->dev, &sch->dev);
801         if (ret) {
802                 CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed "
803                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
804                               cdev->private->dev_id.devno, ret);
805                 put_device(&other_sch->dev);
806                 return;
807         }
808         sch_set_cdev(other_sch, NULL);
809         /* No need to keep a subchannel without ccw device around. */
810         css_sch_device_unregister(other_sch);
811         put_device(&other_sch->dev);
812         sch_attach_device(sch, cdev);
813 }
814
815 static void sch_attach_orphaned_device(struct subchannel *sch,
816                                        struct ccw_device *cdev)
817 {
818         int ret;
819
820         /* Try to move the ccw device to its new subchannel. */
821         ret = device_move(&cdev->dev, &sch->dev);
822         if (ret) {
823                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
824                               "failed (ret=%d)!\n",
825                               cdev->private->dev_id.ssid,
826                               cdev->private->dev_id.devno, ret);
827                 return;
828         }
829         sch_attach_device(sch, cdev);
830 }
831
832 static void sch_create_and_recog_new_device(struct subchannel *sch)
833 {
834         struct ccw_device *cdev;
835
836         /* Need to allocate a new ccw device. */
837         cdev = io_subchannel_create_ccwdev(sch);
838         if (IS_ERR(cdev)) {
839                 /* OK, we did everything we could... */
840                 css_sch_device_unregister(sch);
841                 return;
842         }
843         spin_lock_irq(sch->lock);
844         sch_set_cdev(sch, cdev);
845         spin_unlock_irq(sch->lock);
846         /* Start recognition for the new ccw device. */
847         if (io_subchannel_recog(cdev, sch)) {
848                 spin_lock_irq(sch->lock);
849                 sch_set_cdev(sch, NULL);
850                 spin_unlock_irq(sch->lock);
851                 if (cdev->dev.release)
852                         cdev->dev.release(&cdev->dev);
853                 css_sch_device_unregister(sch);
854         }
855 }
856
857
858 void ccw_device_move_to_orphanage(struct work_struct *work)
859 {
860         struct ccw_device_private *priv;
861         struct ccw_device *cdev;
862         struct ccw_device *replacing_cdev;
863         struct subchannel *sch;
864         int ret;
865         struct channel_subsystem *css;
866         struct ccw_dev_id dev_id;
867
868         priv = container_of(work, struct ccw_device_private, kick_work);
869         cdev = priv->cdev;
870         sch = to_subchannel(cdev->dev.parent);
871         css = to_css(sch->dev.parent);
872         dev_id.devno = sch->schib.pmcw.dev;
873         dev_id.ssid = sch->schid.ssid;
874
875         /*
876          * Move the orphaned ccw device to the orphanage so the replacing
877          * ccw device can take its place on the subchannel.
878          */
879         ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
880         if (ret) {
881                 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
882                               "(ret=%d)!\n", cdev->private->dev_id.ssid,
883                               cdev->private->dev_id.devno, ret);
884                 return;
885         }
886         cdev->ccwlock = css->pseudo_subchannel->lock;
887         /*
888          * Search for the replacing ccw device
889          * - among the disconnected devices
890          * - in the orphanage
891          */
892         replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
893         if (replacing_cdev) {
894                 sch_attach_disconnected_device(sch, replacing_cdev);
895                 return;
896         }
897         replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
898         if (replacing_cdev) {
899                 sch_attach_orphaned_device(sch, replacing_cdev);
900                 return;
901         }
902         sch_create_and_recog_new_device(sch);
903 }
904
905 /*
906  * Register recognized device.
907  */
908 static void
909 io_subchannel_register(struct work_struct *work)
910 {
911         struct ccw_device_private *priv;
912         struct ccw_device *cdev;
913         struct subchannel *sch;
914         int ret;
915         unsigned long flags;
916
917         priv = container_of(work, struct ccw_device_private, kick_work);
918         cdev = priv->cdev;
919         sch = to_subchannel(cdev->dev.parent);
920         css_update_ssd_info(sch);
921         /*
922          * io_subchannel_register() will also be called after device
923          * recognition has been done for a boxed device (which will already
924          * be registered). We need to reprobe since we may now have sense id
925          * information.
926          */
927         if (klist_node_attached(&cdev->dev.knode_parent)) {
928                 if (!cdev->drv) {
929                         ret = device_reprobe(&cdev->dev);
930                         if (ret)
931                                 /* We can't do much here. */
932                                 CIO_MSG_EVENT(2, "device_reprobe() returned"
933                                               " %d for 0.%x.%04x\n", ret,
934                                               cdev->private->dev_id.ssid,
935                                               cdev->private->dev_id.devno);
936                 }
937                 goto out;
938         }
939         /*
940          * Now we know this subchannel will stay, we can throw
941          * our delayed uevent.
942          */
943         sch->dev.uevent_suppress = 0;
944         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
945         /* make it known to the system */
946         ret = ccw_device_register(cdev);
947         if (ret) {
948                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
949                               cdev->private->dev_id.ssid,
950                               cdev->private->dev_id.devno, ret);
951                 put_device(&cdev->dev);
952                 spin_lock_irqsave(sch->lock, flags);
953                 sch_set_cdev(sch, NULL);
954                 spin_unlock_irqrestore(sch->lock, flags);
955                 kfree (cdev->private);
956                 kfree (cdev);
957                 put_device(&sch->dev);
958                 if (atomic_dec_and_test(&ccw_device_init_count))
959                         wake_up(&ccw_device_init_wq);
960                 return;
961         }
962         put_device(&cdev->dev);
963 out:
964         cdev->private->flags.recog_done = 1;
965         put_device(&sch->dev);
966         wake_up(&cdev->private->wait_q);
967         if (atomic_dec_and_test(&ccw_device_init_count))
968                 wake_up(&ccw_device_init_wq);
969 }
970
971 static void ccw_device_call_sch_unregister(struct work_struct *work)
972 {
973         struct ccw_device_private *priv;
974         struct ccw_device *cdev;
975         struct subchannel *sch;
976
977         priv = container_of(work, struct ccw_device_private, kick_work);
978         cdev = priv->cdev;
979         sch = to_subchannel(cdev->dev.parent);
980         css_sch_device_unregister(sch);
981         /* Reset intparm to zeroes. */
982         sch->schib.pmcw.intparm = 0;
983         cio_modify(sch);
984         put_device(&cdev->dev);
985         put_device(&sch->dev);
986 }
987
988 /*
989  * subchannel recognition done. Called from the state machine.
990  */
991 void
992 io_subchannel_recog_done(struct ccw_device *cdev)
993 {
994         struct subchannel *sch;
995
996         if (css_init_done == 0) {
997                 cdev->private->flags.recog_done = 1;
998                 return;
999         }
1000         switch (cdev->private->state) {
1001         case DEV_STATE_NOT_OPER:
1002                 cdev->private->flags.recog_done = 1;
1003                 /* Remove device found not operational. */
1004                 if (!get_device(&cdev->dev))
1005                         break;
1006                 sch = to_subchannel(cdev->dev.parent);
1007                 PREPARE_WORK(&cdev->private->kick_work,
1008                              ccw_device_call_sch_unregister);
1009                 queue_work(slow_path_wq, &cdev->private->kick_work);
1010                 if (atomic_dec_and_test(&ccw_device_init_count))
1011                         wake_up(&ccw_device_init_wq);
1012                 break;
1013         case DEV_STATE_BOXED:
1014                 /* Device did not respond in time. */
1015         case DEV_STATE_OFFLINE:
1016                 /* 
1017                  * We can't register the device in interrupt context so
1018                  * we schedule a work item.
1019                  */
1020                 if (!get_device(&cdev->dev))
1021                         break;
1022                 PREPARE_WORK(&cdev->private->kick_work,
1023                              io_subchannel_register);
1024                 queue_work(slow_path_wq, &cdev->private->kick_work);
1025                 break;
1026         }
1027 }
1028
1029 static int
1030 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1031 {
1032         int rc;
1033         struct ccw_device_private *priv;
1034
1035         sch_set_cdev(sch, cdev);
1036         sch->driver = &io_subchannel_driver;
1037         cdev->ccwlock = sch->lock;
1038
1039         /* Init private data. */
1040         priv = cdev->private;
1041         priv->dev_id.devno = sch->schib.pmcw.dev;
1042         priv->dev_id.ssid = sch->schid.ssid;
1043         priv->schid = sch->schid;
1044         priv->state = DEV_STATE_NOT_OPER;
1045         INIT_LIST_HEAD(&priv->cmb_list);
1046         init_waitqueue_head(&priv->wait_q);
1047         init_timer(&priv->timer);
1048
1049         /* Set an initial name for the device. */
1050         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1051                   sch->schid.ssid, sch->schib.pmcw.dev);
1052
1053         /* Increase counter of devices currently in recognition. */
1054         atomic_inc(&ccw_device_init_count);
1055
1056         /* Start async. device sensing. */
1057         spin_lock_irq(sch->lock);
1058         rc = ccw_device_recognition(cdev);
1059         spin_unlock_irq(sch->lock);
1060         if (rc) {
1061                 if (atomic_dec_and_test(&ccw_device_init_count))
1062                         wake_up(&ccw_device_init_wq);
1063         }
1064         return rc;
1065 }
1066
1067 static void ccw_device_move_to_sch(struct work_struct *work)
1068 {
1069         struct ccw_device_private *priv;
1070         int rc;
1071         struct subchannel *sch;
1072         struct ccw_device *cdev;
1073         struct subchannel *former_parent;
1074
1075         priv = container_of(work, struct ccw_device_private, kick_work);
1076         sch = priv->sch;
1077         cdev = priv->cdev;
1078         former_parent = ccw_device_is_orphan(cdev) ?
1079                 NULL : to_subchannel(get_device(cdev->dev.parent));
1080         mutex_lock(&sch->reg_mutex);
1081         /* Try to move the ccw device to its new subchannel. */
1082         rc = device_move(&cdev->dev, &sch->dev);
1083         mutex_unlock(&sch->reg_mutex);
1084         if (rc) {
1085                 CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel "
1086                               "0.%x.%04x failed (ret=%d)!\n",
1087                               cdev->private->dev_id.ssid,
1088                               cdev->private->dev_id.devno, sch->schid.ssid,
1089                               sch->schid.sch_no, rc);
1090                 css_sch_device_unregister(sch);
1091                 goto out;
1092         }
1093         if (former_parent) {
1094                 spin_lock_irq(former_parent->lock);
1095                 sch_set_cdev(former_parent, NULL);
1096                 spin_unlock_irq(former_parent->lock);
1097                 css_sch_device_unregister(former_parent);
1098                 /* Reset intparm to zeroes. */
1099                 former_parent->schib.pmcw.intparm = 0;
1100                 cio_modify(former_parent);
1101         }
1102         sch_attach_device(sch, cdev);
1103 out:
1104         if (former_parent)
1105                 put_device(&former_parent->dev);
1106         put_device(&cdev->dev);
1107 }
1108
1109 static void io_subchannel_irq(struct subchannel *sch)
1110 {
1111         struct ccw_device *cdev;
1112
1113         cdev = sch_get_cdev(sch);
1114
1115         CIO_TRACE_EVENT(3, "IRQ");
1116         CIO_TRACE_EVENT(3, sch->dev.bus_id);
1117         if (cdev)
1118                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1119 }
1120
1121 static int
1122 io_subchannel_probe (struct subchannel *sch)
1123 {
1124         struct ccw_device *cdev;
1125         int rc;
1126         unsigned long flags;
1127         struct ccw_dev_id dev_id;
1128
1129         cdev = sch_get_cdev(sch);
1130         if (cdev) {
1131                 /*
1132                  * This subchannel already has an associated ccw_device.
1133                  * Register it and exit. This happens for all early
1134                  * device, e.g. the console.
1135                  */
1136                 cdev->dev.groups = ccwdev_attr_groups;
1137                 device_initialize(&cdev->dev);
1138                 ccw_device_register(cdev);
1139                 /*
1140                  * Check if the device is already online. If it is
1141                  * the reference count needs to be corrected
1142                  * (see ccw_device_online and css_init_done for the
1143                  * ugly details).
1144                  */
1145                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1146                     cdev->private->state != DEV_STATE_OFFLINE &&
1147                     cdev->private->state != DEV_STATE_BOXED)
1148                         get_device(&cdev->dev);
1149                 return 0;
1150         }
1151         /*
1152          * First check if a fitting device may be found amongst the
1153          * disconnected devices or in the orphanage.
1154          */
1155         dev_id.devno = sch->schib.pmcw.dev;
1156         dev_id.ssid = sch->schid.ssid;
1157         /* Allocate I/O subchannel private data. */
1158         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1159                                GFP_KERNEL | GFP_DMA);
1160         if (!sch->private)
1161                 return -ENOMEM;
1162         cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1163         if (!cdev)
1164                 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1165                                                      &dev_id);
1166         if (cdev) {
1167                 /*
1168                  * Schedule moving the device until when we have a registered
1169                  * subchannel to move to and succeed the probe. We can
1170                  * unregister later again, when the probe is through.
1171                  */
1172                 cdev->private->sch = sch;
1173                 PREPARE_WORK(&cdev->private->kick_work,
1174                              ccw_device_move_to_sch);
1175                 queue_work(slow_path_wq, &cdev->private->kick_work);
1176                 return 0;
1177         }
1178         cdev = io_subchannel_create_ccwdev(sch);
1179         if (IS_ERR(cdev)) {
1180                 kfree(sch->private);
1181                 return PTR_ERR(cdev);
1182         }
1183         rc = io_subchannel_recog(cdev, sch);
1184         if (rc) {
1185                 spin_lock_irqsave(sch->lock, flags);
1186                 sch_set_cdev(sch, NULL);
1187                 spin_unlock_irqrestore(sch->lock, flags);
1188                 if (cdev->dev.release)
1189                         cdev->dev.release(&cdev->dev);
1190                 kfree(sch->private);
1191         }
1192
1193         return rc;
1194 }
1195
1196 static int
1197 io_subchannel_remove (struct subchannel *sch)
1198 {
1199         struct ccw_device *cdev;
1200         unsigned long flags;
1201
1202         cdev = sch_get_cdev(sch);
1203         if (!cdev)
1204                 return 0;
1205         /* Set ccw device to not operational and drop reference. */
1206         spin_lock_irqsave(cdev->ccwlock, flags);
1207         sch_set_cdev(sch, NULL);
1208         cdev->private->state = DEV_STATE_NOT_OPER;
1209         spin_unlock_irqrestore(cdev->ccwlock, flags);
1210         ccw_device_unregister(cdev);
1211         put_device(&cdev->dev);
1212         kfree(sch->private);
1213         return 0;
1214 }
1215
1216 static int io_subchannel_notify(struct subchannel *sch, int event)
1217 {
1218         struct ccw_device *cdev;
1219
1220         cdev = sch_get_cdev(sch);
1221         if (!cdev)
1222                 return 0;
1223         if (!cdev->drv)
1224                 return 0;
1225         if (!cdev->online)
1226                 return 0;
1227         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
1228 }
1229
1230 static void io_subchannel_verify(struct subchannel *sch)
1231 {
1232         struct ccw_device *cdev;
1233
1234         cdev = sch_get_cdev(sch);
1235         if (cdev)
1236                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1237 }
1238
1239 static void io_subchannel_ioterm(struct subchannel *sch)
1240 {
1241         struct ccw_device *cdev;
1242
1243         cdev = sch_get_cdev(sch);
1244         if (!cdev)
1245                 return;
1246         /* Internal I/O will be retried by the interrupt handler. */
1247         if (cdev->private->flags.intretry)
1248                 return;
1249         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1250         if (cdev->handler)
1251                 cdev->handler(cdev, cdev->private->intparm,
1252                               ERR_PTR(-EIO));
1253 }
1254
1255 static void
1256 io_subchannel_shutdown(struct subchannel *sch)
1257 {
1258         struct ccw_device *cdev;
1259         int ret;
1260
1261         cdev = sch_get_cdev(sch);
1262
1263         if (cio_is_console(sch->schid))
1264                 return;
1265         if (!sch->schib.pmcw.ena)
1266                 /* Nothing to do. */
1267                 return;
1268         ret = cio_disable_subchannel(sch);
1269         if (ret != -EBUSY)
1270                 /* Subchannel is disabled, we're done. */
1271                 return;
1272         cdev->private->state = DEV_STATE_QUIESCE;
1273         if (cdev->handler)
1274                 cdev->handler(cdev, cdev->private->intparm,
1275                               ERR_PTR(-EIO));
1276         ret = ccw_device_cancel_halt_clear(cdev);
1277         if (ret == -EBUSY) {
1278                 ccw_device_set_timeout(cdev, HZ/10);
1279                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1280         }
1281         cio_disable_subchannel(sch);
1282 }
1283
1284 #ifdef CONFIG_CCW_CONSOLE
1285 static struct ccw_device console_cdev;
1286 static struct ccw_device_private console_private;
1287 static int console_cdev_in_use;
1288
1289 static DEFINE_SPINLOCK(ccw_console_lock);
1290
1291 spinlock_t * cio_get_console_lock(void)
1292 {
1293         return &ccw_console_lock;
1294 }
1295
1296 static int
1297 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
1298 {
1299         int rc;
1300
1301         /* Attach subchannel private data. */
1302         sch->private = cio_get_console_priv();
1303         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1304         /* Initialize the ccw_device structure. */
1305         cdev->dev.parent= &sch->dev;
1306         rc = io_subchannel_recog(cdev, sch);
1307         if (rc)
1308                 return rc;
1309
1310         /* Now wait for the async. recognition to come to an end. */
1311         spin_lock_irq(cdev->ccwlock);
1312         while (!dev_fsm_final_state(cdev))
1313                 wait_cons_dev();
1314         rc = -EIO;
1315         if (cdev->private->state != DEV_STATE_OFFLINE)
1316                 goto out_unlock;
1317         ccw_device_online(cdev);
1318         while (!dev_fsm_final_state(cdev))
1319                 wait_cons_dev();
1320         if (cdev->private->state != DEV_STATE_ONLINE)
1321                 goto out_unlock;
1322         rc = 0;
1323 out_unlock:
1324         spin_unlock_irq(cdev->ccwlock);
1325         return 0;
1326 }
1327
1328 struct ccw_device *
1329 ccw_device_probe_console(void)
1330 {
1331         struct subchannel *sch;
1332         int ret;
1333
1334         if (xchg(&console_cdev_in_use, 1) != 0)
1335                 return ERR_PTR(-EBUSY);
1336         sch = cio_probe_console();
1337         if (IS_ERR(sch)) {
1338                 console_cdev_in_use = 0;
1339                 return (void *) sch;
1340         }
1341         memset(&console_cdev, 0, sizeof(struct ccw_device));
1342         memset(&console_private, 0, sizeof(struct ccw_device_private));
1343         console_cdev.private = &console_private;
1344         console_private.cdev = &console_cdev;
1345         ret = ccw_device_console_enable(&console_cdev, sch);
1346         if (ret) {
1347                 cio_release_console();
1348                 console_cdev_in_use = 0;
1349                 return ERR_PTR(ret);
1350         }
1351         console_cdev.online = 1;
1352         return &console_cdev;
1353 }
1354 #endif
1355
1356 /*
1357  * get ccw_device matching the busid, but only if owned by cdrv
1358  */
1359 static int
1360 __ccwdev_check_busid(struct device *dev, void *id)
1361 {
1362         char *bus_id;
1363
1364         bus_id = id;
1365
1366         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1367 }
1368
1369
1370 /**
1371  * get_ccwdev_by_busid() - obtain device from a bus id
1372  * @cdrv: driver the device is owned by
1373  * @bus_id: bus id of the device to be searched
1374  *
1375  * This function searches all devices owned by @cdrv for a device with a bus
1376  * id matching @bus_id.
1377  * Returns:
1378  *  If a match is found, its reference count of the found device is increased
1379  *  and it is returned; else %NULL is returned.
1380  */
1381 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1382                                        const char *bus_id)
1383 {
1384         struct device *dev;
1385         struct device_driver *drv;
1386
1387         drv = get_driver(&cdrv->driver);
1388         if (!drv)
1389                 return NULL;
1390
1391         dev = driver_find_device(drv, NULL, (void *)bus_id,
1392                                  __ccwdev_check_busid);
1393         put_driver(drv);
1394
1395         return dev ? to_ccwdev(dev) : NULL;
1396 }
1397
1398 /************************** device driver handling ************************/
1399
1400 /* This is the implementation of the ccw_driver class. The probe, remove
1401  * and release methods are initially very similar to the device_driver
1402  * implementations, with the difference that they have ccw_device
1403  * arguments.
1404  *
1405  * A ccw driver also contains the information that is needed for
1406  * device matching.
1407  */
1408 static int
1409 ccw_device_probe (struct device *dev)
1410 {
1411         struct ccw_device *cdev = to_ccwdev(dev);
1412         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1413         int ret;
1414
1415         cdev->drv = cdrv; /* to let the driver call _set_online */
1416
1417         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1418
1419         if (ret) {
1420                 cdev->drv = NULL;
1421                 return ret;
1422         }
1423
1424         return 0;
1425 }
1426
1427 static int
1428 ccw_device_remove (struct device *dev)
1429 {
1430         struct ccw_device *cdev = to_ccwdev(dev);
1431         struct ccw_driver *cdrv = cdev->drv;
1432         int ret;
1433
1434         if (cdrv->remove)
1435                 cdrv->remove(cdev);
1436         if (cdev->online) {
1437                 cdev->online = 0;
1438                 spin_lock_irq(cdev->ccwlock);
1439                 ret = ccw_device_offline(cdev);
1440                 spin_unlock_irq(cdev->ccwlock);
1441                 if (ret == 0)
1442                         wait_event(cdev->private->wait_q,
1443                                    dev_fsm_final_state(cdev));
1444                 else
1445                         //FIXME: we can't fail!
1446                         CIO_MSG_EVENT(2, "ccw_device_offline returned %d, "
1447                                       "device 0.%x.%04x\n",
1448                                       ret, cdev->private->dev_id.ssid,
1449                                       cdev->private->dev_id.devno);
1450         }
1451         ccw_device_set_timeout(cdev, 0);
1452         cdev->drv = NULL;
1453         return 0;
1454 }
1455
1456 static void ccw_device_shutdown(struct device *dev)
1457 {
1458         struct ccw_device *cdev;
1459
1460         cdev = to_ccwdev(dev);
1461         if (cdev->drv && cdev->drv->shutdown)
1462                 cdev->drv->shutdown(cdev);
1463         disable_cmf(cdev);
1464 }
1465
1466 struct bus_type ccw_bus_type = {
1467         .name   = "ccw",
1468         .match  = ccw_bus_match,
1469         .uevent = ccw_uevent,
1470         .probe  = ccw_device_probe,
1471         .remove = ccw_device_remove,
1472         .shutdown = ccw_device_shutdown,
1473 };
1474
1475 /**
1476  * ccw_driver_register() - register a ccw driver
1477  * @cdriver: driver to be registered
1478  *
1479  * This function is mainly a wrapper around driver_register().
1480  * Returns:
1481  *   %0 on success and a negative error value on failure.
1482  */
1483 int ccw_driver_register(struct ccw_driver *cdriver)
1484 {
1485         struct device_driver *drv = &cdriver->driver;
1486
1487         drv->bus = &ccw_bus_type;
1488         drv->name = cdriver->name;
1489         drv->owner = cdriver->owner;
1490
1491         return driver_register(drv);
1492 }
1493
1494 /**
1495  * ccw_driver_unregister() - deregister a ccw driver
1496  * @cdriver: driver to be deregistered
1497  *
1498  * This function is mainly a wrapper around driver_unregister().
1499  */
1500 void ccw_driver_unregister(struct ccw_driver *cdriver)
1501 {
1502         driver_unregister(&cdriver->driver);
1503 }
1504
1505 /* Helper func for qdio. */
1506 struct subchannel_id
1507 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1508 {
1509         struct subchannel *sch;
1510
1511         sch = to_subchannel(cdev->dev.parent);
1512         return sch->schid;
1513 }
1514
1515 static int recovery_check(struct device *dev, void *data)
1516 {
1517         struct ccw_device *cdev = to_ccwdev(dev);
1518         int *redo = data;
1519
1520         spin_lock_irq(cdev->ccwlock);
1521         switch (cdev->private->state) {
1522         case DEV_STATE_DISCONNECTED:
1523                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1524                               cdev->private->dev_id.ssid,
1525                               cdev->private->dev_id.devno);
1526                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1527                 *redo = 1;
1528                 break;
1529         case DEV_STATE_DISCONNECTED_SENSE_ID:
1530                 *redo = 1;
1531                 break;
1532         }
1533         spin_unlock_irq(cdev->ccwlock);
1534
1535         return 0;
1536 }
1537
1538 static void recovery_func(unsigned long data)
1539 {
1540         int redo = 0;
1541
1542         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1543         if (redo) {
1544                 spin_lock_irq(&recovery_lock);
1545                 if (!timer_pending(&recovery_timer)) {
1546                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1547                                 recovery_phase++;
1548                         mod_timer(&recovery_timer, jiffies +
1549                                   recovery_delay[recovery_phase] * HZ);
1550                 }
1551                 spin_unlock_irq(&recovery_lock);
1552         } else
1553                 CIO_MSG_EVENT(2, "recovery: end\n");
1554 }
1555
1556 void ccw_device_schedule_recovery(void)
1557 {
1558         unsigned long flags;
1559
1560         CIO_MSG_EVENT(2, "recovery: schedule\n");
1561         spin_lock_irqsave(&recovery_lock, flags);
1562         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1563                 recovery_phase = 0;
1564                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1565         }
1566         spin_unlock_irqrestore(&recovery_lock, flags);
1567 }
1568
1569 MODULE_LICENSE("GPL");
1570 EXPORT_SYMBOL(ccw_device_set_online);
1571 EXPORT_SYMBOL(ccw_device_set_offline);
1572 EXPORT_SYMBOL(ccw_driver_register);
1573 EXPORT_SYMBOL(ccw_driver_unregister);
1574 EXPORT_SYMBOL(get_ccwdev_by_busid);
1575 EXPORT_SYMBOL(ccw_bus_type);
1576 EXPORT_SYMBOL(ccw_device_work);
1577 EXPORT_SYMBOL(ccw_device_notify_work);
1578 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);