[PATCH] s390: ccw device reconnect oops.
[linux-2.6] / drivers / s390 / cio / device.c
1 /*
2  *  drivers/s390/cio/device.c
3  *  bus driver for ccw devices
4  *   $Revision: 1.131 $
5  *
6  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
7  *                       IBM Corporation
8  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
9  *               Cornelia Huck (cohuck@de.ibm.com)
10  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
11  */
12 #include <linux/config.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/spinlock.h>
16 #include <linux/errno.h>
17 #include <linux/err.h>
18 #include <linux/slab.h>
19 #include <linux/list.h>
20 #include <linux/device.h>
21 #include <linux/workqueue.h>
22
23 #include <asm/ccwdev.h>
24 #include <asm/cio.h>
25
26 #include "cio.h"
27 #include "css.h"
28 #include "device.h"
29 #include "ioasm.h"
30
31 /******************* bus type handling ***********************/
32
33 /* The Linux driver model distinguishes between a bus type and
34  * the bus itself. Of course we only have one channel
35  * subsystem driver and one channel system per machine, but
36  * we still use the abstraction. T.R. says it's a good idea. */
37 static int
38 ccw_bus_match (struct device * dev, struct device_driver * drv)
39 {
40         struct ccw_device *cdev = to_ccwdev(dev);
41         struct ccw_driver *cdrv = to_ccwdrv(drv);
42         const struct ccw_device_id *ids = cdrv->ids, *found;
43
44         if (!ids)
45                 return 0;
46
47         found = ccw_device_id_match(ids, &cdev->id);
48         if (!found)
49                 return 0;
50
51         cdev->id.driver_info = found->driver_info;
52
53         return 1;
54 }
55
56 /*
57  * Hotplugging interface for ccw devices.
58  * Heavily modeled on pci and usb hotplug.
59  */
60 static int
61 ccw_hotplug (struct device *dev, char **envp, int num_envp,
62              char *buffer, int buffer_size)
63 {
64         struct ccw_device *cdev = to_ccwdev(dev);
65         int i = 0;
66         int length = 0;
67
68         if (!cdev)
69                 return -ENODEV;
70
71         /* what we want to pass to /sbin/hotplug */
72
73         envp[i++] = buffer;
74         length += scnprintf(buffer, buffer_size - length, "CU_TYPE=%04X",
75                            cdev->id.cu_type);
76         if ((buffer_size - length <= 0) || (i >= num_envp))
77                 return -ENOMEM;
78         ++length;
79         buffer += length;
80
81         envp[i++] = buffer;
82         length += scnprintf(buffer, buffer_size - length, "CU_MODEL=%02X",
83                            cdev->id.cu_model);
84         if ((buffer_size - length <= 0) || (i >= num_envp))
85                 return -ENOMEM;
86         ++length;
87         buffer += length;
88
89         /* The next two can be zero, that's ok for us */
90         envp[i++] = buffer;
91         length += scnprintf(buffer, buffer_size - length, "DEV_TYPE=%04X",
92                            cdev->id.dev_type);
93         if ((buffer_size - length <= 0) || (i >= num_envp))
94                 return -ENOMEM;
95         ++length;
96         buffer += length;
97
98         envp[i++] = buffer;
99         length += scnprintf(buffer, buffer_size - length, "DEV_MODEL=%02X",
100                            cdev->id.dev_model);
101         if ((buffer_size - length <= 0) || (i >= num_envp))
102                 return -ENOMEM;
103
104         envp[i] = 0;
105
106         return 0;
107 }
108
109 struct bus_type ccw_bus_type = {
110         .name  = "ccw",
111         .match = &ccw_bus_match,
112         .hotplug = &ccw_hotplug,
113 };
114
115 static int io_subchannel_probe (struct device *);
116 static int io_subchannel_remove (struct device *);
117 void io_subchannel_irq (struct device *);
118 static int io_subchannel_notify(struct device *, int);
119 static void io_subchannel_verify(struct device *);
120 static void io_subchannel_ioterm(struct device *);
121 static void io_subchannel_shutdown(struct device *);
122
123 struct css_driver io_subchannel_driver = {
124         .subchannel_type = SUBCHANNEL_TYPE_IO,
125         .drv = {
126                 .name = "io_subchannel",
127                 .bus  = &css_bus_type,
128                 .probe = &io_subchannel_probe,
129                 .remove = &io_subchannel_remove,
130                 .shutdown = &io_subchannel_shutdown,
131         },
132         .irq = io_subchannel_irq,
133         .notify = io_subchannel_notify,
134         .verify = io_subchannel_verify,
135         .termination = io_subchannel_ioterm,
136 };
137
138 struct workqueue_struct *ccw_device_work;
139 struct workqueue_struct *ccw_device_notify_work;
140 static wait_queue_head_t ccw_device_init_wq;
141 static atomic_t ccw_device_init_count;
142
143 static int __init
144 init_ccw_bus_type (void)
145 {
146         int ret;
147
148         init_waitqueue_head(&ccw_device_init_wq);
149         atomic_set(&ccw_device_init_count, 0);
150
151         ccw_device_work = create_singlethread_workqueue("cio");
152         if (!ccw_device_work)
153                 return -ENOMEM; /* FIXME: better errno ? */
154         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
155         if (!ccw_device_notify_work) {
156                 ret = -ENOMEM; /* FIXME: better errno ? */
157                 goto out_err;
158         }
159         slow_path_wq = create_singlethread_workqueue("kslowcrw");
160         if (!slow_path_wq) {
161                 ret = -ENOMEM; /* FIXME: better errno ? */
162                 goto out_err;
163         }
164         if ((ret = bus_register (&ccw_bus_type)))
165                 goto out_err;
166
167         if ((ret = driver_register(&io_subchannel_driver.drv)))
168                 goto out_err;
169
170         wait_event(ccw_device_init_wq,
171                    atomic_read(&ccw_device_init_count) == 0);
172         flush_workqueue(ccw_device_work);
173         return 0;
174 out_err:
175         if (ccw_device_work)
176                 destroy_workqueue(ccw_device_work);
177         if (ccw_device_notify_work)
178                 destroy_workqueue(ccw_device_notify_work);
179         if (slow_path_wq)
180                 destroy_workqueue(slow_path_wq);
181         return ret;
182 }
183
184 static void __exit
185 cleanup_ccw_bus_type (void)
186 {
187         driver_unregister(&io_subchannel_driver.drv);
188         bus_unregister(&ccw_bus_type);
189         destroy_workqueue(ccw_device_notify_work);
190         destroy_workqueue(ccw_device_work);
191 }
192
193 subsys_initcall(init_ccw_bus_type);
194 module_exit(cleanup_ccw_bus_type);
195
196 /************************ device handling **************************/
197
198 /*
199  * A ccw_device has some interfaces in sysfs in addition to the
200  * standard ones.
201  * The following entries are designed to export the information which
202  * resided in 2.4 in /proc/subchannels. Subchannel and device number
203  * are obvious, so they don't have an entry :)
204  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
205  */
206 static ssize_t
207 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
208 {
209         struct subchannel *sch = to_subchannel(dev);
210         struct ssd_info *ssd = &sch->ssd_info;
211         ssize_t ret = 0;
212         int chp;
213
214         for (chp = 0; chp < 8; chp++)
215                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
216
217         ret += sprintf (buf+ret, "\n");
218         return min((ssize_t)PAGE_SIZE, ret);
219 }
220
221 static ssize_t
222 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
223 {
224         struct subchannel *sch = to_subchannel(dev);
225         struct pmcw *pmcw = &sch->schib.pmcw;
226
227         return sprintf (buf, "%02x %02x %02x\n",
228                         pmcw->pim, pmcw->pam, pmcw->pom);
229 }
230
231 static ssize_t
232 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
233 {
234         struct ccw_device *cdev = to_ccwdev(dev);
235         struct ccw_device_id *id = &(cdev->id);
236
237         if (id->dev_type != 0)
238                 return sprintf(buf, "%04x/%02x\n",
239                                 id->dev_type, id->dev_model);
240         else
241                 return sprintf(buf, "n/a\n");
242 }
243
244 static ssize_t
245 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
246 {
247         struct ccw_device *cdev = to_ccwdev(dev);
248         struct ccw_device_id *id = &(cdev->id);
249
250         return sprintf(buf, "%04x/%02x\n",
251                        id->cu_type, id->cu_model);
252 }
253
254 static ssize_t
255 online_show (struct device *dev, struct device_attribute *attr, char *buf)
256 {
257         struct ccw_device *cdev = to_ccwdev(dev);
258
259         return sprintf(buf, cdev->online ? "1\n" : "0\n");
260 }
261
262 static void
263 ccw_device_remove_disconnected(struct ccw_device *cdev)
264 {
265         struct subchannel *sch;
266         /*
267          * Forced offline in disconnected state means
268          * 'throw away device'.
269          */
270         sch = to_subchannel(cdev->dev.parent);
271         device_unregister(&sch->dev);
272         /* Reset intparm to zeroes. */
273         sch->schib.pmcw.intparm = 0;
274         cio_modify(sch);
275         put_device(&sch->dev);
276 }
277
278 int
279 ccw_device_set_offline(struct ccw_device *cdev)
280 {
281         int ret;
282
283         if (!cdev)
284                 return -ENODEV;
285         if (!cdev->online || !cdev->drv)
286                 return -EINVAL;
287
288         if (cdev->drv->set_offline) {
289                 ret = cdev->drv->set_offline(cdev);
290                 if (ret != 0)
291                         return ret;
292         }
293         cdev->online = 0;
294         spin_lock_irq(cdev->ccwlock);
295         ret = ccw_device_offline(cdev);
296         if (ret == -ENODEV) {
297                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
298                         cdev->private->state = DEV_STATE_OFFLINE;
299                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
300                 }
301                 spin_unlock_irq(cdev->ccwlock);
302                 return ret;
303         }
304         spin_unlock_irq(cdev->ccwlock);
305         if (ret == 0)
306                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
307         else {
308                 pr_debug("ccw_device_offline returned %d, device %s\n",
309                          ret, cdev->dev.bus_id);
310                 cdev->online = 1;
311         }
312         return ret;
313 }
314
315 int
316 ccw_device_set_online(struct ccw_device *cdev)
317 {
318         int ret;
319
320         if (!cdev)
321                 return -ENODEV;
322         if (cdev->online || !cdev->drv)
323                 return -EINVAL;
324
325         spin_lock_irq(cdev->ccwlock);
326         ret = ccw_device_online(cdev);
327         spin_unlock_irq(cdev->ccwlock);
328         if (ret == 0)
329                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
330         else {
331                 pr_debug("ccw_device_online returned %d, device %s\n",
332                          ret, cdev->dev.bus_id);
333                 return ret;
334         }
335         if (cdev->private->state != DEV_STATE_ONLINE)
336                 return -ENODEV;
337         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
338                 cdev->online = 1;
339                 return 0;
340         }
341         spin_lock_irq(cdev->ccwlock);
342         ret = ccw_device_offline(cdev);
343         spin_unlock_irq(cdev->ccwlock);
344         if (ret == 0)
345                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
346         else 
347                 pr_debug("ccw_device_offline returned %d, device %s\n",
348                          ret, cdev->dev.bus_id);
349         return (ret = 0) ? -ENODEV : ret;
350 }
351
352 static ssize_t
353 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
354 {
355         struct ccw_device *cdev = to_ccwdev(dev);
356         int i, force, ret;
357         char *tmp;
358
359         if (atomic_compare_and_swap(0, 1, &cdev->private->onoff))
360                 return -EAGAIN;
361
362         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
363                 atomic_set(&cdev->private->onoff, 0);
364                 return -EINVAL;
365         }
366         if (!strncmp(buf, "force\n", count)) {
367                 force = 1;
368                 i = 1;
369         } else {
370                 force = 0;
371                 i = simple_strtoul(buf, &tmp, 16);
372         }
373         if (i == 1) {
374                 /* Do device recognition, if needed. */
375                 if (cdev->id.cu_type == 0) {
376                         ret = ccw_device_recognition(cdev);
377                         if (ret) {
378                                 printk(KERN_WARNING"Couldn't start recognition "
379                                        "for device %s (ret=%d)\n",
380                                        cdev->dev.bus_id, ret);
381                                 goto out;
382                         }
383                         wait_event(cdev->private->wait_q,
384                                    cdev->private->flags.recog_done);
385                 }
386                 if (cdev->drv && cdev->drv->set_online)
387                         ccw_device_set_online(cdev);
388         } else if (i == 0) {
389                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
390                         ccw_device_remove_disconnected(cdev);
391                 else if (cdev->drv && cdev->drv->set_offline)
392                         ccw_device_set_offline(cdev);
393         }
394         if (force && cdev->private->state == DEV_STATE_BOXED) {
395                 ret = ccw_device_stlck(cdev);
396                 if (ret) {
397                         printk(KERN_WARNING"ccw_device_stlck for device %s "
398                                "returned %d!\n", cdev->dev.bus_id, ret);
399                         goto out;
400                 }
401                 /* Do device recognition, if needed. */
402                 if (cdev->id.cu_type == 0) {
403                         cdev->private->state = DEV_STATE_NOT_OPER;
404                         ret = ccw_device_recognition(cdev);
405                         if (ret) {
406                                 printk(KERN_WARNING"Couldn't start recognition "
407                                        "for device %s (ret=%d)\n",
408                                        cdev->dev.bus_id, ret);
409                                 goto out;
410                         }
411                         wait_event(cdev->private->wait_q,
412                                    cdev->private->flags.recog_done);
413                 }
414                 if (cdev->drv && cdev->drv->set_online)
415                         ccw_device_set_online(cdev);
416         }
417         out:
418         if (cdev->drv)
419                 module_put(cdev->drv->owner);
420         atomic_set(&cdev->private->onoff, 0);
421         return count;
422 }
423
424 static ssize_t
425 available_show (struct device *dev, struct device_attribute *attr, char *buf)
426 {
427         struct ccw_device *cdev = to_ccwdev(dev);
428         struct subchannel *sch;
429
430         switch (cdev->private->state) {
431         case DEV_STATE_BOXED:
432                 return sprintf(buf, "boxed\n");
433         case DEV_STATE_DISCONNECTED:
434         case DEV_STATE_DISCONNECTED_SENSE_ID:
435         case DEV_STATE_NOT_OPER:
436                 sch = to_subchannel(dev->parent);
437                 if (!sch->lpm)
438                         return sprintf(buf, "no path\n");
439                 else
440                         return sprintf(buf, "no device\n");
441         default:
442                 /* All other states considered fine. */
443                 return sprintf(buf, "good\n");
444         }
445 }
446
447 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
448 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
449 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
450 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
451 static DEVICE_ATTR(online, 0644, online_show, online_store);
452 extern struct device_attribute dev_attr_cmb_enable;
453 static DEVICE_ATTR(availability, 0444, available_show, NULL);
454
455 static struct attribute * subch_attrs[] = {
456         &dev_attr_chpids.attr,
457         &dev_attr_pimpampom.attr,
458         NULL,
459 };
460
461 static struct attribute_group subch_attr_group = {
462         .attrs = subch_attrs,
463 };
464
465 static inline int
466 subchannel_add_files (struct device *dev)
467 {
468         return sysfs_create_group(&dev->kobj, &subch_attr_group);
469 }
470
471 static struct attribute * ccwdev_attrs[] = {
472         &dev_attr_devtype.attr,
473         &dev_attr_cutype.attr,
474         &dev_attr_online.attr,
475         &dev_attr_cmb_enable.attr,
476         &dev_attr_availability.attr,
477         NULL,
478 };
479
480 static struct attribute_group ccwdev_attr_group = {
481         .attrs = ccwdev_attrs,
482 };
483
484 static inline int
485 device_add_files (struct device *dev)
486 {
487         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
488 }
489
490 static inline void
491 device_remove_files(struct device *dev)
492 {
493         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
494 }
495
496 /* this is a simple abstraction for device_register that sets the
497  * correct bus type and adds the bus specific files */
498 int
499 ccw_device_register(struct ccw_device *cdev)
500 {
501         struct device *dev = &cdev->dev;
502         int ret;
503
504         dev->bus = &ccw_bus_type;
505
506         if ((ret = device_add(dev)))
507                 return ret;
508
509         set_bit(1, &cdev->private->registered);
510         if ((ret = device_add_files(dev))) {
511                 if (test_and_clear_bit(1, &cdev->private->registered))
512                         device_del(dev);
513         }
514         return ret;
515 }
516
517 struct match_data {
518         unsigned int  devno;
519         struct ccw_device * sibling;
520 };
521
522 static int
523 match_devno(struct device * dev, void * data)
524 {
525         struct match_data * d = (struct match_data *)data;
526         struct ccw_device * cdev;
527
528         cdev = to_ccwdev(dev);
529         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
530             (cdev->private->devno == d->devno) &&
531             (cdev != d->sibling)) {
532                 cdev->private->state = DEV_STATE_NOT_OPER;
533                 return 1;
534         }
535         return 0;
536 }
537
538 static struct ccw_device *
539 get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
540 {
541         struct device *dev;
542         struct match_data data = {
543                 .devno  = devno,
544                 .sibling = sibling,
545         };
546
547         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
548
549         return dev ? to_ccwdev(dev) : NULL;
550 }
551
552 static void
553 ccw_device_add_changed(void *data)
554 {
555
556         struct ccw_device *cdev;
557
558         cdev = (struct ccw_device *)data;
559         if (device_add(&cdev->dev)) {
560                 put_device(&cdev->dev);
561                 return;
562         }
563         set_bit(1, &cdev->private->registered);
564         if (device_add_files(&cdev->dev)) {
565                 if (test_and_clear_bit(1, &cdev->private->registered))
566                         device_unregister(&cdev->dev);
567         }
568 }
569
570 extern int css_get_ssd_info(struct subchannel *sch);
571
572 void
573 ccw_device_do_unreg_rereg(void *data)
574 {
575         struct ccw_device *cdev;
576         struct subchannel *sch;
577         int need_rename;
578
579         cdev = (struct ccw_device *)data;
580         sch = to_subchannel(cdev->dev.parent);
581         if (cdev->private->devno != sch->schib.pmcw.dev) {
582                 /*
583                  * The device number has changed. This is usually only when
584                  * a device has been detached under VM and then re-appeared
585                  * on another subchannel because of a different attachment
586                  * order than before. Ideally, we should should just switch
587                  * subchannels, but unfortunately, this is not possible with
588                  * the current implementation.
589                  * Instead, we search for the old subchannel for this device
590                  * number and deregister so there are no collisions with the
591                  * newly registered ccw_device.
592                  * FIXME: Find another solution so the block layer doesn't
593                  *        get possibly sick...
594                  */
595                 struct ccw_device *other_cdev;
596
597                 need_rename = 1;
598                 other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
599                                                       cdev);
600                 if (other_cdev) {
601                         struct subchannel *other_sch;
602
603                         other_sch = to_subchannel(other_cdev->dev.parent);
604                         if (get_device(&other_sch->dev)) {
605                                 stsch(other_sch->irq, &other_sch->schib);
606                                 if (other_sch->schib.pmcw.dnv) {
607                                         other_sch->schib.pmcw.intparm = 0;
608                                         cio_modify(other_sch);
609                                 }
610                                 device_unregister(&other_sch->dev);
611                         }
612                 }
613                 /* Update ssd info here. */
614                 css_get_ssd_info(sch);
615                 cdev->private->devno = sch->schib.pmcw.dev;
616         } else
617                 need_rename = 0;
618         device_remove_files(&cdev->dev);
619         if (test_and_clear_bit(1, &cdev->private->registered))
620                 device_del(&cdev->dev);
621         if (need_rename)
622                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
623                           sch->schib.pmcw.dev);
624         PREPARE_WORK(&cdev->private->kick_work,
625                      ccw_device_add_changed, (void *)cdev);
626         queue_work(ccw_device_work, &cdev->private->kick_work);
627 }
628
629 static void
630 ccw_device_release(struct device *dev)
631 {
632         struct ccw_device *cdev;
633
634         cdev = to_ccwdev(dev);
635         kfree(cdev->private);
636         kfree(cdev);
637 }
638
639 /*
640  * Register recognized device.
641  */
642 static void
643 io_subchannel_register(void *data)
644 {
645         struct ccw_device *cdev;
646         struct subchannel *sch;
647         int ret;
648         unsigned long flags;
649
650         cdev = (struct ccw_device *) data;
651         sch = to_subchannel(cdev->dev.parent);
652
653         if (klist_node_attached(&cdev->dev.knode_parent)) {
654                 bus_rescan_devices(&ccw_bus_type);
655                 goto out;
656         }
657         /* make it known to the system */
658         ret = ccw_device_register(cdev);
659         if (ret) {
660                 printk (KERN_WARNING "%s: could not register %s\n",
661                         __func__, cdev->dev.bus_id);
662                 put_device(&cdev->dev);
663                 spin_lock_irqsave(&sch->lock, flags);
664                 sch->dev.driver_data = NULL;
665                 spin_unlock_irqrestore(&sch->lock, flags);
666                 kfree (cdev->private);
667                 kfree (cdev);
668                 put_device(&sch->dev);
669                 if (atomic_dec_and_test(&ccw_device_init_count))
670                         wake_up(&ccw_device_init_wq);
671                 return;
672         }
673
674         ret = subchannel_add_files(cdev->dev.parent);
675         if (ret)
676                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
677                        __func__, sch->dev.bus_id);
678         put_device(&cdev->dev);
679 out:
680         cdev->private->flags.recog_done = 1;
681         put_device(&sch->dev);
682         wake_up(&cdev->private->wait_q);
683         if (atomic_dec_and_test(&ccw_device_init_count))
684                 wake_up(&ccw_device_init_wq);
685 }
686
687 void
688 ccw_device_call_sch_unregister(void *data)
689 {
690         struct ccw_device *cdev = data;
691         struct subchannel *sch;
692
693         sch = to_subchannel(cdev->dev.parent);
694         device_unregister(&sch->dev);
695         /* Reset intparm to zeroes. */
696         sch->schib.pmcw.intparm = 0;
697         cio_modify(sch);
698         put_device(&cdev->dev);
699         put_device(&sch->dev);
700 }
701
702 /*
703  * subchannel recognition done. Called from the state machine.
704  */
705 void
706 io_subchannel_recog_done(struct ccw_device *cdev)
707 {
708         struct subchannel *sch;
709
710         if (css_init_done == 0) {
711                 cdev->private->flags.recog_done = 1;
712                 return;
713         }
714         switch (cdev->private->state) {
715         case DEV_STATE_NOT_OPER:
716                 cdev->private->flags.recog_done = 1;
717                 /* Remove device found not operational. */
718                 if (!get_device(&cdev->dev))
719                         break;
720                 sch = to_subchannel(cdev->dev.parent);
721                 PREPARE_WORK(&cdev->private->kick_work,
722                              ccw_device_call_sch_unregister, (void *) cdev);
723                 queue_work(slow_path_wq, &cdev->private->kick_work);
724                 if (atomic_dec_and_test(&ccw_device_init_count))
725                         wake_up(&ccw_device_init_wq);
726                 break;
727         case DEV_STATE_BOXED:
728                 /* Device did not respond in time. */
729         case DEV_STATE_OFFLINE:
730                 /* 
731                  * We can't register the device in interrupt context so
732                  * we schedule a work item.
733                  */
734                 if (!get_device(&cdev->dev))
735                         break;
736                 PREPARE_WORK(&cdev->private->kick_work,
737                              io_subchannel_register, (void *) cdev);
738                 queue_work(slow_path_wq, &cdev->private->kick_work);
739                 break;
740         }
741 }
742
743 static int
744 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
745 {
746         int rc;
747         struct ccw_device_private *priv;
748
749         sch->dev.driver_data = cdev;
750         sch->driver = &io_subchannel_driver;
751         cdev->ccwlock = &sch->lock;
752         /* Init private data. */
753         priv = cdev->private;
754         priv->devno = sch->schib.pmcw.dev;
755         priv->irq = sch->irq;
756         priv->state = DEV_STATE_NOT_OPER;
757         INIT_LIST_HEAD(&priv->cmb_list);
758         init_waitqueue_head(&priv->wait_q);
759         init_timer(&priv->timer);
760
761         /* Set an initial name for the device. */
762         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
763                   sch->schib.pmcw.dev);
764
765         /* Increase counter of devices currently in recognition. */
766         atomic_inc(&ccw_device_init_count);
767
768         /* Start async. device sensing. */
769         spin_lock_irq(&sch->lock);
770         rc = ccw_device_recognition(cdev);
771         spin_unlock_irq(&sch->lock);
772         if (rc) {
773                 if (atomic_dec_and_test(&ccw_device_init_count))
774                         wake_up(&ccw_device_init_wq);
775         }
776         return rc;
777 }
778
779 static int
780 io_subchannel_probe (struct device *pdev)
781 {
782         struct subchannel *sch;
783         struct ccw_device *cdev;
784         int rc;
785         unsigned long flags;
786
787         sch = to_subchannel(pdev);
788         if (sch->dev.driver_data) {
789                 /*
790                  * This subchannel already has an associated ccw_device.
791                  * Register it and exit. This happens for all early
792                  * device, e.g. the console.
793                  */
794                 cdev = sch->dev.driver_data;
795                 device_initialize(&cdev->dev);
796                 ccw_device_register(cdev);
797                 subchannel_add_files(&sch->dev);
798                 /*
799                  * Check if the device is already online. If it is
800                  * the reference count needs to be corrected
801                  * (see ccw_device_online and css_init_done for the
802                  * ugly details).
803                  */
804                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
805                     cdev->private->state != DEV_STATE_OFFLINE &&
806                     cdev->private->state != DEV_STATE_BOXED)
807                         get_device(&cdev->dev);
808                 return 0;
809         }
810         cdev  = kmalloc (sizeof(*cdev), GFP_KERNEL);
811         if (!cdev)
812                 return -ENOMEM;
813         memset(cdev, 0, sizeof(struct ccw_device));
814         cdev->private = kmalloc(sizeof(struct ccw_device_private), 
815                                 GFP_KERNEL | GFP_DMA);
816         if (!cdev->private) {
817                 kfree(cdev);
818                 return -ENOMEM;
819         }
820         memset(cdev->private, 0, sizeof(struct ccw_device_private));
821         atomic_set(&cdev->private->onoff, 0);
822         cdev->dev = (struct device) {
823                 .parent = pdev,
824                 .release = ccw_device_release,
825         };
826         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
827         /* Do first half of device_register. */
828         device_initialize(&cdev->dev);
829
830         if (!get_device(&sch->dev)) {
831                 if (cdev->dev.release)
832                         cdev->dev.release(&cdev->dev);
833                 return -ENODEV;
834         }
835
836         rc = io_subchannel_recog(cdev, to_subchannel(pdev));
837         if (rc) {
838                 spin_lock_irqsave(&sch->lock, flags);
839                 sch->dev.driver_data = NULL;
840                 spin_unlock_irqrestore(&sch->lock, flags);
841                 if (cdev->dev.release)
842                         cdev->dev.release(&cdev->dev);
843         }
844
845         return rc;
846 }
847
848 static void
849 ccw_device_unregister(void *data)
850 {
851         struct ccw_device *cdev;
852
853         cdev = (struct ccw_device *)data;
854         if (test_and_clear_bit(1, &cdev->private->registered))
855                 device_unregister(&cdev->dev);
856         put_device(&cdev->dev);
857 }
858
859 static int
860 io_subchannel_remove (struct device *dev)
861 {
862         struct ccw_device *cdev;
863         unsigned long flags;
864
865         if (!dev->driver_data)
866                 return 0;
867         cdev = dev->driver_data;
868         /* Set ccw device to not operational and drop reference. */
869         spin_lock_irqsave(cdev->ccwlock, flags);
870         dev->driver_data = NULL;
871         cdev->private->state = DEV_STATE_NOT_OPER;
872         spin_unlock_irqrestore(cdev->ccwlock, flags);
873         /*
874          * Put unregistration on workqueue to avoid livelocks on the css bus
875          * semaphore.
876          */
877         if (get_device(&cdev->dev)) {
878                 PREPARE_WORK(&cdev->private->kick_work,
879                              ccw_device_unregister, (void *) cdev);
880                 queue_work(ccw_device_work, &cdev->private->kick_work);
881         }
882         return 0;
883 }
884
885 static int
886 io_subchannel_notify(struct device *dev, int event)
887 {
888         struct ccw_device *cdev;
889
890         cdev = dev->driver_data;
891         if (!cdev)
892                 return 0;
893         if (!cdev->drv)
894                 return 0;
895         if (!cdev->online)
896                 return 0;
897         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
898 }
899
900 static void
901 io_subchannel_verify(struct device *dev)
902 {
903         struct ccw_device *cdev;
904
905         cdev = dev->driver_data;
906         if (cdev)
907                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
908 }
909
910 static void
911 io_subchannel_ioterm(struct device *dev)
912 {
913         struct ccw_device *cdev;
914
915         cdev = dev->driver_data;
916         if (!cdev)
917                 return;
918         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
919         if (cdev->handler)
920                 cdev->handler(cdev, cdev->private->intparm,
921                               ERR_PTR(-EIO));
922 }
923
924 static void
925 io_subchannel_shutdown(struct device *dev)
926 {
927         struct subchannel *sch;
928         struct ccw_device *cdev;
929         int ret;
930
931         sch = to_subchannel(dev);
932         cdev = dev->driver_data;
933
934         if (cio_is_console(sch->irq))
935                 return;
936         if (!sch->schib.pmcw.ena)
937                 /* Nothing to do. */
938                 return;
939         ret = cio_disable_subchannel(sch);
940         if (ret != -EBUSY)
941                 /* Subchannel is disabled, we're done. */
942                 return;
943         cdev->private->state = DEV_STATE_QUIESCE;
944         if (cdev->handler)
945                 cdev->handler(cdev, cdev->private->intparm,
946                               ERR_PTR(-EIO));
947         ret = ccw_device_cancel_halt_clear(cdev);
948         if (ret == -EBUSY) {
949                 ccw_device_set_timeout(cdev, HZ/10);
950                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
951         }
952         cio_disable_subchannel(sch);
953 }
954
955 #ifdef CONFIG_CCW_CONSOLE
956 static struct ccw_device console_cdev;
957 static struct ccw_device_private console_private;
958 static int console_cdev_in_use;
959
960 static int
961 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
962 {
963         int rc;
964
965         /* Initialize the ccw_device structure. */
966         cdev->dev = (struct device) {
967                 .parent = &sch->dev,
968         };
969         /* Initialize the subchannel structure */
970         sch->dev.parent = &css_bus_device;
971         sch->dev.bus = &css_bus_type;
972
973         rc = io_subchannel_recog(cdev, sch);
974         if (rc)
975                 return rc;
976
977         /* Now wait for the async. recognition to come to an end. */
978         spin_lock_irq(cdev->ccwlock);
979         while (!dev_fsm_final_state(cdev))
980                 wait_cons_dev();
981         rc = -EIO;
982         if (cdev->private->state != DEV_STATE_OFFLINE)
983                 goto out_unlock;
984         ccw_device_online(cdev);
985         while (!dev_fsm_final_state(cdev))
986                 wait_cons_dev();
987         if (cdev->private->state != DEV_STATE_ONLINE)
988                 goto out_unlock;
989         rc = 0;
990 out_unlock:
991         spin_unlock_irq(cdev->ccwlock);
992         return 0;
993 }
994
995 struct ccw_device *
996 ccw_device_probe_console(void)
997 {
998         struct subchannel *sch;
999         int ret;
1000
1001         if (xchg(&console_cdev_in_use, 1) != 0)
1002                 return NULL;
1003         sch = cio_probe_console();
1004         if (IS_ERR(sch)) {
1005                 console_cdev_in_use = 0;
1006                 return (void *) sch;
1007         }
1008         memset(&console_cdev, 0, sizeof(struct ccw_device));
1009         memset(&console_private, 0, sizeof(struct ccw_device_private));
1010         console_cdev.private = &console_private;
1011         ret = ccw_device_console_enable(&console_cdev, sch);
1012         if (ret) {
1013                 cio_release_console();
1014                 console_cdev_in_use = 0;
1015                 return ERR_PTR(ret);
1016         }
1017         console_cdev.online = 1;
1018         return &console_cdev;
1019 }
1020 #endif
1021
1022 /*
1023  * get ccw_device matching the busid, but only if owned by cdrv
1024  */
1025 static int
1026 __ccwdev_check_busid(struct device *dev, void *id)
1027 {
1028         char *bus_id;
1029
1030         bus_id = (char *)id;
1031
1032         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1033 }
1034
1035
1036 struct ccw_device *
1037 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1038 {
1039         struct device *dev;
1040         struct device_driver *drv;
1041
1042         drv = get_driver(&cdrv->driver);
1043         if (!drv)
1044                 return NULL;
1045
1046         dev = driver_find_device(drv, NULL, (void *)bus_id,
1047                                  __ccwdev_check_busid);
1048         put_driver(drv);
1049
1050         return dev ? to_ccwdev(dev) : 0;
1051 }
1052
1053 /************************** device driver handling ************************/
1054
1055 /* This is the implementation of the ccw_driver class. The probe, remove
1056  * and release methods are initially very similar to the device_driver
1057  * implementations, with the difference that they have ccw_device
1058  * arguments.
1059  *
1060  * A ccw driver also contains the information that is needed for
1061  * device matching.
1062  */
1063 static int
1064 ccw_device_probe (struct device *dev)
1065 {
1066         struct ccw_device *cdev = to_ccwdev(dev);
1067         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1068         int ret;
1069
1070         cdev->drv = cdrv; /* to let the driver call _set_online */
1071
1072         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1073
1074         if (ret) {
1075                 cdev->drv = 0;
1076                 return ret;
1077         }
1078
1079         return 0;
1080 }
1081
1082 static int
1083 ccw_device_remove (struct device *dev)
1084 {
1085         struct ccw_device *cdev = to_ccwdev(dev);
1086         struct ccw_driver *cdrv = cdev->drv;
1087         int ret;
1088
1089         pr_debug("removing device %s\n", cdev->dev.bus_id);
1090         if (cdrv->remove)
1091                 cdrv->remove(cdev);
1092         if (cdev->online) {
1093                 cdev->online = 0;
1094                 spin_lock_irq(cdev->ccwlock);
1095                 ret = ccw_device_offline(cdev);
1096                 spin_unlock_irq(cdev->ccwlock);
1097                 if (ret == 0)
1098                         wait_event(cdev->private->wait_q,
1099                                    dev_fsm_final_state(cdev));
1100                 else
1101                         //FIXME: we can't fail!
1102                         pr_debug("ccw_device_offline returned %d, device %s\n",
1103                                  ret, cdev->dev.bus_id);
1104         }
1105         ccw_device_set_timeout(cdev, 0);
1106         cdev->drv = 0;
1107         return 0;
1108 }
1109
1110 int
1111 ccw_driver_register (struct ccw_driver *cdriver)
1112 {
1113         struct device_driver *drv = &cdriver->driver;
1114
1115         drv->bus = &ccw_bus_type;
1116         drv->name = cdriver->name;
1117         drv->probe = ccw_device_probe;
1118         drv->remove = ccw_device_remove;
1119
1120         return driver_register(drv);
1121 }
1122
1123 void
1124 ccw_driver_unregister (struct ccw_driver *cdriver)
1125 {
1126         driver_unregister(&cdriver->driver);
1127 }
1128
1129 MODULE_LICENSE("GPL");
1130 EXPORT_SYMBOL(ccw_device_set_online);
1131 EXPORT_SYMBOL(ccw_device_set_offline);
1132 EXPORT_SYMBOL(ccw_driver_register);
1133 EXPORT_SYMBOL(ccw_driver_unregister);
1134 EXPORT_SYMBOL(get_ccwdev_by_busid);
1135 EXPORT_SYMBOL(ccw_bus_type);
1136 EXPORT_SYMBOL(ccw_device_work);
1137 EXPORT_SYMBOL(ccw_device_notify_work);