94bdd4d8a4c9c205b72ef1b92dc598fb37b38d0e
[linux-2.6.git] / 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
21 #include <asm/ccwdev.h>
22 #include <asm/cio.h>
23 #include <asm/param.h>          /* HZ */
24
25 #include "cio.h"
26 #include "css.h"
27 #include "device.h"
28 #include "ioasm.h"
29
30 /******************* bus type handling ***********************/
31
32 /* The Linux driver model distinguishes between a bus type and
33  * the bus itself. Of course we only have one channel
34  * subsystem driver and one channel system per machine, but
35  * we still use the abstraction. T.R. says it's a good idea. */
36 static int
37 ccw_bus_match (struct device * dev, struct device_driver * drv)
38 {
39         struct ccw_device *cdev = to_ccwdev(dev);
40         struct ccw_driver *cdrv = to_ccwdrv(drv);
41         const struct ccw_device_id *ids = cdrv->ids, *found;
42
43         if (!ids)
44                 return 0;
45
46         found = ccw_device_id_match(ids, &cdev->id);
47         if (!found)
48                 return 0;
49
50         cdev->id.driver_info = found->driver_info;
51
52         return 1;
53 }
54
55 /* Store modalias string delimited by prefix/suffix string into buffer with
56  * specified size. Return length of resulting string (excluding trailing '\0')
57  * even if string doesn't fit buffer (snprintf semantics). */
58 static int snprint_alias(char *buf, size_t size, const char *prefix,
59                          struct ccw_device_id *id, const char *suffix)
60 {
61         int len;
62
63         len = snprintf(buf, size, "%sccw:t%04Xm%02X", prefix, id->cu_type,
64                        id->cu_model);
65         if (len > size)
66                 return len;
67         buf += len;
68         size -= len;
69
70         if (id->dev_type != 0)
71                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
72                                 id->dev_model, suffix);
73         else
74                 len += snprintf(buf, size, "dtdm%s", suffix);
75
76         return len;
77 }
78
79 /* Set up environment variables for ccw device uevent. Return 0 on success,
80  * non-zero otherwise. */
81 static int ccw_uevent(struct device *dev, char **envp, int num_envp,
82                       char *buffer, int buffer_size)
83 {
84         struct ccw_device *cdev = to_ccwdev(dev);
85         struct ccw_device_id *id = &(cdev->id);
86         int i = 0;
87         int len;
88
89         /* CU_TYPE= */
90         len = snprintf(buffer, buffer_size, "CU_TYPE=%04X", id->cu_type) + 1;
91         if (len > buffer_size || i >= num_envp)
92                 return -ENOMEM;
93         envp[i++] = buffer;
94         buffer += len;
95         buffer_size -= len;
96
97         /* CU_MODEL= */
98         len = snprintf(buffer, buffer_size, "CU_MODEL=%02X", id->cu_model) + 1;
99         if (len > buffer_size || i >= num_envp)
100                 return -ENOMEM;
101         envp[i++] = buffer;
102         buffer += len;
103         buffer_size -= len;
104
105         /* The next two can be zero, that's ok for us */
106         /* DEV_TYPE= */
107         len = snprintf(buffer, buffer_size, "DEV_TYPE=%04X", id->dev_type) + 1;
108         if (len > buffer_size || i >= num_envp)
109                 return -ENOMEM;
110         envp[i++] = buffer;
111         buffer += len;
112         buffer_size -= len;
113
114         /* DEV_MODEL= */
115         len = snprintf(buffer, buffer_size, "DEV_MODEL=%02X",
116                         (unsigned char) id->dev_model) + 1;
117         if (len > buffer_size || i >= num_envp)
118                 return -ENOMEM;
119         envp[i++] = buffer;
120         buffer += len;
121         buffer_size -= len;
122
123         /* MODALIAS=  */
124         len = snprint_alias(buffer, buffer_size, "MODALIAS=", id, "") + 1;
125         if (len > buffer_size || i >= num_envp)
126                 return -ENOMEM;
127         envp[i++] = buffer;
128         buffer += len;
129         buffer_size -= len;
130
131         envp[i] = NULL;
132
133         return 0;
134 }
135
136 struct bus_type ccw_bus_type;
137
138 static int io_subchannel_probe (struct subchannel *);
139 static int io_subchannel_remove (struct subchannel *);
140 void io_subchannel_irq (struct device *);
141 static int io_subchannel_notify(struct device *, int);
142 static void io_subchannel_verify(struct device *);
143 static void io_subchannel_ioterm(struct device *);
144 static void io_subchannel_shutdown(struct subchannel *);
145
146 struct css_driver io_subchannel_driver = {
147         .subchannel_type = SUBCHANNEL_TYPE_IO,
148         .drv = {
149                 .name = "io_subchannel",
150                 .bus  = &css_bus_type,
151         },
152         .irq = io_subchannel_irq,
153         .notify = io_subchannel_notify,
154         .verify = io_subchannel_verify,
155         .termination = io_subchannel_ioterm,
156         .probe = io_subchannel_probe,
157         .remove = io_subchannel_remove,
158         .shutdown = io_subchannel_shutdown,
159 };
160
161 struct workqueue_struct *ccw_device_work;
162 struct workqueue_struct *ccw_device_notify_work;
163 wait_queue_head_t ccw_device_init_wq;
164 atomic_t ccw_device_init_count;
165
166 static int __init
167 init_ccw_bus_type (void)
168 {
169         int ret;
170
171         init_waitqueue_head(&ccw_device_init_wq);
172         atomic_set(&ccw_device_init_count, 0);
173
174         ccw_device_work = create_singlethread_workqueue("cio");
175         if (!ccw_device_work)
176                 return -ENOMEM; /* FIXME: better errno ? */
177         ccw_device_notify_work = create_singlethread_workqueue("cio_notify");
178         if (!ccw_device_notify_work) {
179                 ret = -ENOMEM; /* FIXME: better errno ? */
180                 goto out_err;
181         }
182         slow_path_wq = create_singlethread_workqueue("kslowcrw");
183         if (!slow_path_wq) {
184                 ret = -ENOMEM; /* FIXME: better errno ? */
185                 goto out_err;
186         }
187         if ((ret = bus_register (&ccw_bus_type)))
188                 goto out_err;
189
190         if ((ret = driver_register(&io_subchannel_driver.drv)))
191                 goto out_err;
192
193         wait_event(ccw_device_init_wq,
194                    atomic_read(&ccw_device_init_count) == 0);
195         flush_workqueue(ccw_device_work);
196         return 0;
197 out_err:
198         if (ccw_device_work)
199                 destroy_workqueue(ccw_device_work);
200         if (ccw_device_notify_work)
201                 destroy_workqueue(ccw_device_notify_work);
202         if (slow_path_wq)
203                 destroy_workqueue(slow_path_wq);
204         return ret;
205 }
206
207 static void __exit
208 cleanup_ccw_bus_type (void)
209 {
210         driver_unregister(&io_subchannel_driver.drv);
211         bus_unregister(&ccw_bus_type);
212         destroy_workqueue(ccw_device_notify_work);
213         destroy_workqueue(ccw_device_work);
214 }
215
216 subsys_initcall(init_ccw_bus_type);
217 module_exit(cleanup_ccw_bus_type);
218
219 /************************ device handling **************************/
220
221 /*
222  * A ccw_device has some interfaces in sysfs in addition to the
223  * standard ones.
224  * The following entries are designed to export the information which
225  * resided in 2.4 in /proc/subchannels. Subchannel and device number
226  * are obvious, so they don't have an entry :)
227  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
228  */
229 static ssize_t
230 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
231 {
232         struct subchannel *sch = to_subchannel(dev);
233         struct ssd_info *ssd = &sch->ssd_info;
234         ssize_t ret = 0;
235         int chp;
236
237         for (chp = 0; chp < 8; chp++)
238                 ret += sprintf (buf+ret, "%02x ", ssd->chpid[chp]);
239
240         ret += sprintf (buf+ret, "\n");
241         return min((ssize_t)PAGE_SIZE, ret);
242 }
243
244 static ssize_t
245 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
246 {
247         struct subchannel *sch = to_subchannel(dev);
248         struct pmcw *pmcw = &sch->schib.pmcw;
249
250         return sprintf (buf, "%02x %02x %02x\n",
251                         pmcw->pim, pmcw->pam, pmcw->pom);
252 }
253
254 static ssize_t
255 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
256 {
257         struct ccw_device *cdev = to_ccwdev(dev);
258         struct ccw_device_id *id = &(cdev->id);
259
260         if (id->dev_type != 0)
261                 return sprintf(buf, "%04x/%02x\n",
262                                 id->dev_type, id->dev_model);
263         else
264                 return sprintf(buf, "n/a\n");
265 }
266
267 static ssize_t
268 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
269 {
270         struct ccw_device *cdev = to_ccwdev(dev);
271         struct ccw_device_id *id = &(cdev->id);
272
273         return sprintf(buf, "%04x/%02x\n",
274                        id->cu_type, id->cu_model);
275 }
276
277 static ssize_t
278 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
279 {
280         struct ccw_device *cdev = to_ccwdev(dev);
281         struct ccw_device_id *id = &(cdev->id);
282         int len;
283
284         len = snprint_alias(buf, PAGE_SIZE, "", id, "\n") + 1;
285
286         return len > PAGE_SIZE ? PAGE_SIZE : len;
287 }
288
289 static ssize_t
290 online_show (struct device *dev, struct device_attribute *attr, char *buf)
291 {
292         struct ccw_device *cdev = to_ccwdev(dev);
293
294         return sprintf(buf, cdev->online ? "1\n" : "0\n");
295 }
296
297 static void
298 ccw_device_remove_disconnected(struct ccw_device *cdev)
299 {
300         struct subchannel *sch;
301         /*
302          * Forced offline in disconnected state means
303          * 'throw away device'.
304          */
305         sch = to_subchannel(cdev->dev.parent);
306         css_sch_device_unregister(sch);
307         /* Reset intparm to zeroes. */
308         sch->schib.pmcw.intparm = 0;
309         cio_modify(sch);
310         put_device(&sch->dev);
311 }
312
313 int
314 ccw_device_set_offline(struct ccw_device *cdev)
315 {
316         int ret;
317
318         if (!cdev)
319                 return -ENODEV;
320         if (!cdev->online || !cdev->drv)
321                 return -EINVAL;
322
323         if (cdev->drv->set_offline) {
324                 ret = cdev->drv->set_offline(cdev);
325                 if (ret != 0)
326                         return ret;
327         }
328         cdev->online = 0;
329         spin_lock_irq(cdev->ccwlock);
330         ret = ccw_device_offline(cdev);
331         if (ret == -ENODEV) {
332                 if (cdev->private->state != DEV_STATE_NOT_OPER) {
333                         cdev->private->state = DEV_STATE_OFFLINE;
334                         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
335                 }
336                 spin_unlock_irq(cdev->ccwlock);
337                 return ret;
338         }
339         spin_unlock_irq(cdev->ccwlock);
340         if (ret == 0)
341                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
342         else {
343                 pr_debug("ccw_device_offline returned %d, device %s\n",
344                          ret, cdev->dev.bus_id);
345                 cdev->online = 1;
346         }
347         return ret;
348 }
349
350 int
351 ccw_device_set_online(struct ccw_device *cdev)
352 {
353         int ret;
354
355         if (!cdev)
356                 return -ENODEV;
357         if (cdev->online || !cdev->drv)
358                 return -EINVAL;
359
360         spin_lock_irq(cdev->ccwlock);
361         ret = ccw_device_online(cdev);
362         spin_unlock_irq(cdev->ccwlock);
363         if (ret == 0)
364                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
365         else {
366                 pr_debug("ccw_device_online returned %d, device %s\n",
367                          ret, cdev->dev.bus_id);
368                 return ret;
369         }
370         if (cdev->private->state != DEV_STATE_ONLINE)
371                 return -ENODEV;
372         if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
373                 cdev->online = 1;
374                 return 0;
375         }
376         spin_lock_irq(cdev->ccwlock);
377         ret = ccw_device_offline(cdev);
378         spin_unlock_irq(cdev->ccwlock);
379         if (ret == 0)
380                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
381         else 
382                 pr_debug("ccw_device_offline returned %d, device %s\n",
383                          ret, cdev->dev.bus_id);
384         return (ret == 0) ? -ENODEV : ret;
385 }
386
387 static ssize_t
388 online_store (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
389 {
390         struct ccw_device *cdev = to_ccwdev(dev);
391         int i, force, ret;
392         char *tmp;
393
394         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
395                 return -EAGAIN;
396
397         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
398                 atomic_set(&cdev->private->onoff, 0);
399                 return -EINVAL;
400         }
401         if (!strncmp(buf, "force\n", count)) {
402                 force = 1;
403                 i = 1;
404         } else {
405                 force = 0;
406                 i = simple_strtoul(buf, &tmp, 16);
407         }
408         if (i == 1) {
409                 /* Do device recognition, if needed. */
410                 if (cdev->id.cu_type == 0) {
411                         ret = ccw_device_recognition(cdev);
412                         if (ret) {
413                                 printk(KERN_WARNING"Couldn't start recognition "
414                                        "for device %s (ret=%d)\n",
415                                        cdev->dev.bus_id, ret);
416                                 goto out;
417                         }
418                         wait_event(cdev->private->wait_q,
419                                    cdev->private->flags.recog_done);
420                 }
421                 if (cdev->drv && cdev->drv->set_online)
422                         ccw_device_set_online(cdev);
423         } else if (i == 0) {
424                 if (cdev->private->state == DEV_STATE_DISCONNECTED)
425                         ccw_device_remove_disconnected(cdev);
426                 else if (cdev->drv && cdev->drv->set_offline)
427                         ccw_device_set_offline(cdev);
428         }
429         if (force && cdev->private->state == DEV_STATE_BOXED) {
430                 ret = ccw_device_stlck(cdev);
431                 if (ret) {
432                         printk(KERN_WARNING"ccw_device_stlck for device %s "
433                                "returned %d!\n", cdev->dev.bus_id, ret);
434                         goto out;
435                 }
436                 /* Do device recognition, if needed. */
437                 if (cdev->id.cu_type == 0) {
438                         cdev->private->state = DEV_STATE_NOT_OPER;
439                         ret = ccw_device_recognition(cdev);
440                         if (ret) {
441                                 printk(KERN_WARNING"Couldn't start recognition "
442                                        "for device %s (ret=%d)\n",
443                                        cdev->dev.bus_id, ret);
444                                 goto out;
445                         }
446                         wait_event(cdev->private->wait_q,
447                                    cdev->private->flags.recog_done);
448                 }
449                 if (cdev->drv && cdev->drv->set_online)
450                         ccw_device_set_online(cdev);
451         }
452         out:
453         if (cdev->drv)
454                 module_put(cdev->drv->owner);
455         atomic_set(&cdev->private->onoff, 0);
456         return count;
457 }
458
459 static ssize_t
460 available_show (struct device *dev, struct device_attribute *attr, char *buf)
461 {
462         struct ccw_device *cdev = to_ccwdev(dev);
463         struct subchannel *sch;
464
465         switch (cdev->private->state) {
466         case DEV_STATE_BOXED:
467                 return sprintf(buf, "boxed\n");
468         case DEV_STATE_DISCONNECTED:
469         case DEV_STATE_DISCONNECTED_SENSE_ID:
470         case DEV_STATE_NOT_OPER:
471                 sch = to_subchannel(dev->parent);
472                 if (!sch->lpm)
473                         return sprintf(buf, "no path\n");
474                 else
475                         return sprintf(buf, "no device\n");
476         default:
477                 /* All other states considered fine. */
478                 return sprintf(buf, "good\n");
479         }
480 }
481
482 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
483 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
484 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
485 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
486 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
487 static DEVICE_ATTR(online, 0644, online_show, online_store);
488 extern struct device_attribute dev_attr_cmb_enable;
489 static DEVICE_ATTR(availability, 0444, available_show, NULL);
490
491 static struct attribute * subch_attrs[] = {
492         &dev_attr_chpids.attr,
493         &dev_attr_pimpampom.attr,
494         NULL,
495 };
496
497 static struct attribute_group subch_attr_group = {
498         .attrs = subch_attrs,
499 };
500
501 static inline int
502 subchannel_add_files (struct device *dev)
503 {
504         return sysfs_create_group(&dev->kobj, &subch_attr_group);
505 }
506
507 static struct attribute * ccwdev_attrs[] = {
508         &dev_attr_devtype.attr,
509         &dev_attr_cutype.attr,
510         &dev_attr_modalias.attr,
511         &dev_attr_online.attr,
512         &dev_attr_cmb_enable.attr,
513         &dev_attr_availability.attr,
514         NULL,
515 };
516
517 static struct attribute_group ccwdev_attr_group = {
518         .attrs = ccwdev_attrs,
519 };
520
521 static inline int
522 device_add_files (struct device *dev)
523 {
524         return sysfs_create_group(&dev->kobj, &ccwdev_attr_group);
525 }
526
527 static inline void
528 device_remove_files(struct device *dev)
529 {
530         sysfs_remove_group(&dev->kobj, &ccwdev_attr_group);
531 }
532
533 /* this is a simple abstraction for device_register that sets the
534  * correct bus type and adds the bus specific files */
535 int
536 ccw_device_register(struct ccw_device *cdev)
537 {
538         struct device *dev = &cdev->dev;
539         int ret;
540
541         dev->bus = &ccw_bus_type;
542
543         if ((ret = device_add(dev)))
544                 return ret;
545
546         set_bit(1, &cdev->private->registered);
547         if ((ret = device_add_files(dev))) {
548                 if (test_and_clear_bit(1, &cdev->private->registered))
549                         device_del(dev);
550         }
551         return ret;
552 }
553
554 struct match_data {
555         struct ccw_dev_id dev_id;
556         struct ccw_device * sibling;
557 };
558
559 static int
560 match_devno(struct device * dev, void * data)
561 {
562         struct match_data * d = data;
563         struct ccw_device * cdev;
564
565         cdev = to_ccwdev(dev);
566         if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
567             ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
568             (cdev != d->sibling)) {
569                 cdev->private->state = DEV_STATE_NOT_OPER;
570                 return 1;
571         }
572         return 0;
573 }
574
575 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
576                                                      struct ccw_device *sibling)
577 {
578         struct device *dev;
579         struct match_data data;
580
581         data.dev_id = *dev_id;
582         data.sibling = sibling;
583         dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
584
585         return dev ? to_ccwdev(dev) : NULL;
586 }
587
588 static void
589 ccw_device_add_changed(void *data)
590 {
591
592         struct ccw_device *cdev;
593
594         cdev = data;
595         if (device_add(&cdev->dev)) {
596                 put_device(&cdev->dev);
597                 return;
598         }
599         set_bit(1, &cdev->private->registered);
600         if (device_add_files(&cdev->dev)) {
601                 if (test_and_clear_bit(1, &cdev->private->registered))
602                         device_unregister(&cdev->dev);
603         }
604 }
605
606 extern int css_get_ssd_info(struct subchannel *sch);
607
608 void
609 ccw_device_do_unreg_rereg(void *data)
610 {
611         struct ccw_device *cdev;
612         struct subchannel *sch;
613         int need_rename;
614
615         cdev = data;
616         sch = to_subchannel(cdev->dev.parent);
617         if (cdev->private->dev_id.devno != sch->schib.pmcw.dev) {
618                 /*
619                  * The device number has changed. This is usually only when
620                  * a device has been detached under VM and then re-appeared
621                  * on another subchannel because of a different attachment
622                  * order than before. Ideally, we should should just switch
623                  * subchannels, but unfortunately, this is not possible with
624                  * the current implementation.
625                  * Instead, we search for the old subchannel for this device
626                  * number and deregister so there are no collisions with the
627                  * newly registered ccw_device.
628                  * FIXME: Find another solution so the block layer doesn't
629                  *        get possibly sick...
630                  */
631                 struct ccw_device *other_cdev;
632                 struct ccw_dev_id dev_id;
633
634                 need_rename = 1;
635                 dev_id.devno = sch->schib.pmcw.dev;
636                 dev_id.ssid = sch->schid.ssid;
637                 other_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
638                 if (other_cdev) {
639                         struct subchannel *other_sch;
640
641                         other_sch = to_subchannel(other_cdev->dev.parent);
642                         if (get_device(&other_sch->dev)) {
643                                 stsch(other_sch->schid, &other_sch->schib);
644                                 if (other_sch->schib.pmcw.dnv) {
645                                         other_sch->schib.pmcw.intparm = 0;
646                                         cio_modify(other_sch);
647                                 }
648                                 css_sch_device_unregister(other_sch);
649                         }
650                 }
651                 /* Update ssd info here. */
652                 css_get_ssd_info(sch);
653                 cdev->private->dev_id.devno = sch->schib.pmcw.dev;
654         } else
655                 need_rename = 0;
656         device_remove_files(&cdev->dev);
657         if (test_and_clear_bit(1, &cdev->private->registered))
658                 device_del(&cdev->dev);
659         if (need_rename)
660                 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
661                           sch->schid.ssid, sch->schib.pmcw.dev);
662         PREPARE_WORK(&cdev->private->kick_work,
663                      ccw_device_add_changed, cdev);
664         queue_work(ccw_device_work, &cdev->private->kick_work);
665 }
666
667 static void
668 ccw_device_release(struct device *dev)
669 {
670         struct ccw_device *cdev;
671
672         cdev = to_ccwdev(dev);
673         kfree(cdev->private);
674         kfree(cdev);
675 }
676
677 /*
678  * Register recognized device.
679  */
680 static void
681 io_subchannel_register(void *data)
682 {
683         struct ccw_device *cdev;
684         struct subchannel *sch;
685         int ret;
686         unsigned long flags;
687
688         cdev = data;
689         sch = to_subchannel(cdev->dev.parent);
690
691         if (klist_node_attached(&cdev->dev.knode_parent)) {
692                 bus_rescan_devices(&ccw_bus_type);
693                 goto out;
694         }
695         /* make it known to the system */
696         ret = ccw_device_register(cdev);
697         if (ret) {
698                 printk (KERN_WARNING "%s: could not register %s\n",
699                         __func__, cdev->dev.bus_id);
700                 put_device(&cdev->dev);
701                 spin_lock_irqsave(&sch->lock, flags);
702                 sch->dev.driver_data = NULL;
703                 spin_unlock_irqrestore(&sch->lock, flags);
704                 kfree (cdev->private);
705                 kfree (cdev);
706                 put_device(&sch->dev);
707                 if (atomic_dec_and_test(&ccw_device_init_count))
708                         wake_up(&ccw_device_init_wq);
709                 return;
710         }
711
712         ret = subchannel_add_files(cdev->dev.parent);
713         if (ret)
714                 printk(KERN_WARNING "%s: could not add attributes to %s\n",
715                        __func__, sch->dev.bus_id);
716         put_device(&cdev->dev);
717 out:
718         cdev->private->flags.recog_done = 1;
719         put_device(&sch->dev);
720         wake_up(&cdev->private->wait_q);
721         if (atomic_dec_and_test(&ccw_device_init_count))
722                 wake_up(&ccw_device_init_wq);
723 }
724
725 void
726 ccw_device_call_sch_unregister(void *data)
727 {
728         struct ccw_device *cdev = data;
729         struct subchannel *sch;
730
731         sch = to_subchannel(cdev->dev.parent);
732         css_sch_device_unregister(sch);
733         /* Reset intparm to zeroes. */
734         sch->schib.pmcw.intparm = 0;
735         cio_modify(sch);
736         put_device(&cdev->dev);
737         put_device(&sch->dev);
738 }
739
740 /*
741  * subchannel recognition done. Called from the state machine.
742  */
743 void
744 io_subchannel_recog_done(struct ccw_device *cdev)
745 {
746         struct subchannel *sch;
747
748         if (css_init_done == 0) {
749                 cdev->private->flags.recog_done = 1;
750                 return;
751         }
752         switch (cdev->private->state) {
753         case DEV_STATE_NOT_OPER:
754                 cdev->private->flags.recog_done = 1;
755                 /* Remove device found not operational. */
756                 if (!get_device(&cdev->dev))
757                         break;
758                 sch = to_subchannel(cdev->dev.parent);
759                 PREPARE_WORK(&cdev->private->kick_work,
760                              ccw_device_call_sch_unregister, cdev);
761                 queue_work(slow_path_wq, &cdev->private->kick_work);
762                 if (atomic_dec_and_test(&ccw_device_init_count))
763                         wake_up(&ccw_device_init_wq);
764                 break;
765         case DEV_STATE_BOXED:
766                 /* Device did not respond in time. */
767         case DEV_STATE_OFFLINE:
768                 /* 
769                  * We can't register the device in interrupt context so
770                  * we schedule a work item.
771                  */
772                 if (!get_device(&cdev->dev))
773                         break;
774                 PREPARE_WORK(&cdev->private->kick_work,
775                              io_subchannel_register, cdev);
776                 queue_work(slow_path_wq, &cdev->private->kick_work);
777                 break;
778         }
779 }
780
781 static int
782 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
783 {
784         int rc;
785         struct ccw_device_private *priv;
786
787         sch->dev.driver_data = cdev;
788         sch->driver = &io_subchannel_driver;
789         cdev->ccwlock = &sch->lock;
790
791         /* Init private data. */
792         priv = cdev->private;
793         priv->dev_id.devno = sch->schib.pmcw.dev;
794         priv->dev_id.ssid = sch->schid.ssid;
795         priv->schid = sch->schid;
796         priv->state = DEV_STATE_NOT_OPER;
797         INIT_LIST_HEAD(&priv->cmb_list);
798         init_waitqueue_head(&priv->wait_q);
799         init_timer(&priv->timer);
800
801         /* Set an initial name for the device. */
802         snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
803                   sch->schid.ssid, sch->schib.pmcw.dev);
804
805         /* Increase counter of devices currently in recognition. */
806         atomic_inc(&ccw_device_init_count);
807
808         /* Start async. device sensing. */
809         spin_lock_irq(&sch->lock);
810         rc = ccw_device_recognition(cdev);
811         spin_unlock_irq(&sch->lock);
812         if (rc) {
813                 if (atomic_dec_and_test(&ccw_device_init_count))
814                         wake_up(&ccw_device_init_wq);
815         }
816         return rc;
817 }
818
819 static int
820 io_subchannel_probe (struct subchannel *sch)
821 {
822         struct ccw_device *cdev;
823         int rc;
824         unsigned long flags;
825
826         if (sch->dev.driver_data) {
827                 /*
828                  * This subchannel already has an associated ccw_device.
829                  * Register it and exit. This happens for all early
830                  * device, e.g. the console.
831                  */
832                 cdev = sch->dev.driver_data;
833                 device_initialize(&cdev->dev);
834                 ccw_device_register(cdev);
835                 subchannel_add_files(&sch->dev);
836                 /*
837                  * Check if the device is already online. If it is
838                  * the reference count needs to be corrected
839                  * (see ccw_device_online and css_init_done for the
840                  * ugly details).
841                  */
842                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
843                     cdev->private->state != DEV_STATE_OFFLINE &&
844                     cdev->private->state != DEV_STATE_BOXED)
845                         get_device(&cdev->dev);
846                 return 0;
847         }
848         cdev = kzalloc (sizeof(*cdev), GFP_KERNEL);
849         if (!cdev)
850                 return -ENOMEM;
851         cdev->private = kzalloc(sizeof(struct ccw_device_private),
852                                 GFP_KERNEL | GFP_DMA);
853         if (!cdev->private) {
854                 kfree(cdev);
855                 return -ENOMEM;
856         }
857         atomic_set(&cdev->private->onoff, 0);
858         cdev->dev.parent = &sch->dev;
859         cdev->dev.release = ccw_device_release;
860         INIT_LIST_HEAD(&cdev->private->kick_work.entry);
861         /* Do first half of device_register. */
862         device_initialize(&cdev->dev);
863
864         if (!get_device(&sch->dev)) {
865                 if (cdev->dev.release)
866                         cdev->dev.release(&cdev->dev);
867                 return -ENODEV;
868         }
869
870         rc = io_subchannel_recog(cdev, sch);
871         if (rc) {
872                 spin_lock_irqsave(&sch->lock, flags);
873                 sch->dev.driver_data = NULL;
874                 spin_unlock_irqrestore(&sch->lock, flags);
875                 if (cdev->dev.release)
876                         cdev->dev.release(&cdev->dev);
877         }
878
879         return rc;
880 }
881
882 static void
883 ccw_device_unregister(void *data)
884 {
885         struct ccw_device *cdev;
886
887         cdev = (struct ccw_device *)data;
888         if (test_and_clear_bit(1, &cdev->private->registered))
889                 device_unregister(&cdev->dev);
890         put_device(&cdev->dev);
891 }
892
893 static int
894 io_subchannel_remove (struct subchannel *sch)
895 {
896         struct ccw_device *cdev;
897         unsigned long flags;
898
899         if (!sch->dev.driver_data)
900                 return 0;
901         cdev = sch->dev.driver_data;
902         /* Set ccw device to not operational and drop reference. */
903         spin_lock_irqsave(cdev->ccwlock, flags);
904         sch->dev.driver_data = NULL;
905         cdev->private->state = DEV_STATE_NOT_OPER;
906         spin_unlock_irqrestore(cdev->ccwlock, flags);
907         /*
908          * Put unregistration on workqueue to avoid livelocks on the css bus
909          * semaphore.
910          */
911         if (get_device(&cdev->dev)) {
912                 PREPARE_WORK(&cdev->private->kick_work,
913                              ccw_device_unregister, cdev);
914                 queue_work(ccw_device_work, &cdev->private->kick_work);
915         }
916         return 0;
917 }
918
919 static int
920 io_subchannel_notify(struct device *dev, int event)
921 {
922         struct ccw_device *cdev;
923
924         cdev = dev->driver_data;
925         if (!cdev)
926                 return 0;
927         if (!cdev->drv)
928                 return 0;
929         if (!cdev->online)
930                 return 0;
931         return cdev->drv->notify ? cdev->drv->notify(cdev, event) : 0;
932 }
933
934 static void
935 io_subchannel_verify(struct device *dev)
936 {
937         struct ccw_device *cdev;
938
939         cdev = dev->driver_data;
940         if (cdev)
941                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
942 }
943
944 static void
945 io_subchannel_ioterm(struct device *dev)
946 {
947         struct ccw_device *cdev;
948
949         cdev = dev->driver_data;
950         if (!cdev)
951                 return;
952         cdev->private->state = DEV_STATE_CLEAR_VERIFY;
953         if (cdev->handler)
954                 cdev->handler(cdev, cdev->private->intparm,
955                               ERR_PTR(-EIO));
956 }
957
958 static void
959 io_subchannel_shutdown(struct subchannel *sch)
960 {
961         struct ccw_device *cdev;
962         int ret;
963
964         cdev = sch->dev.driver_data;
965
966         if (cio_is_console(sch->schid))
967                 return;
968         if (!sch->schib.pmcw.ena)
969                 /* Nothing to do. */
970                 return;
971         ret = cio_disable_subchannel(sch);
972         if (ret != -EBUSY)
973                 /* Subchannel is disabled, we're done. */
974                 return;
975         cdev->private->state = DEV_STATE_QUIESCE;
976         if (cdev->handler)
977                 cdev->handler(cdev, cdev->private->intparm,
978                               ERR_PTR(-EIO));
979         ret = ccw_device_cancel_halt_clear(cdev);
980         if (ret == -EBUSY) {
981                 ccw_device_set_timeout(cdev, HZ/10);
982                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
983         }
984         cio_disable_subchannel(sch);
985 }
986
987 #ifdef CONFIG_CCW_CONSOLE
988 static struct ccw_device console_cdev;
989 static struct ccw_device_private console_private;
990 static int console_cdev_in_use;
991
992 static int
993 ccw_device_console_enable (struct ccw_device *cdev, struct subchannel *sch)
994 {
995         int rc;
996
997         /* Initialize the ccw_device structure. */
998         cdev->dev.parent= &sch->dev;
999         rc = io_subchannel_recog(cdev, sch);
1000         if (rc)
1001                 return rc;
1002
1003         /* Now wait for the async. recognition to come to an end. */
1004         spin_lock_irq(cdev->ccwlock);
1005         while (!dev_fsm_final_state(cdev))
1006                 wait_cons_dev();
1007         rc = -EIO;
1008         if (cdev->private->state != DEV_STATE_OFFLINE)
1009                 goto out_unlock;
1010         ccw_device_online(cdev);
1011         while (!dev_fsm_final_state(cdev))
1012                 wait_cons_dev();
1013         if (cdev->private->state != DEV_STATE_ONLINE)
1014                 goto out_unlock;
1015         rc = 0;
1016 out_unlock:
1017         spin_unlock_irq(cdev->ccwlock);
1018         return 0;
1019 }
1020
1021 struct ccw_device *
1022 ccw_device_probe_console(void)
1023 {
1024         struct subchannel *sch;
1025         int ret;
1026
1027         if (xchg(&console_cdev_in_use, 1) != 0)
1028                 return ERR_PTR(-EBUSY);
1029         sch = cio_probe_console();
1030         if (IS_ERR(sch)) {
1031                 console_cdev_in_use = 0;
1032                 return (void *) sch;
1033         }
1034         memset(&console_cdev, 0, sizeof(struct ccw_device));
1035         memset(&console_private, 0, sizeof(struct ccw_device_private));
1036         console_cdev.private = &console_private;
1037         ret = ccw_device_console_enable(&console_cdev, sch);
1038         if (ret) {
1039                 cio_release_console();
1040                 console_cdev_in_use = 0;
1041                 return ERR_PTR(ret);
1042         }
1043         console_cdev.online = 1;
1044         return &console_cdev;
1045 }
1046 #endif
1047
1048 /*
1049  * get ccw_device matching the busid, but only if owned by cdrv
1050  */
1051 static int
1052 __ccwdev_check_busid(struct device *dev, void *id)
1053 {
1054         char *bus_id;
1055
1056         bus_id = id;
1057
1058         return (strncmp(bus_id, dev->bus_id, BUS_ID_SIZE) == 0);
1059 }
1060
1061
1062 struct ccw_device *
1063 get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
1064 {
1065         struct device *dev;
1066         struct device_driver *drv;
1067
1068         drv = get_driver(&cdrv->driver);
1069         if (!drv)
1070                 return NULL;
1071
1072         dev = driver_find_device(drv, NULL, (void *)bus_id,
1073                                  __ccwdev_check_busid);
1074         put_driver(drv);
1075
1076         return dev ? to_ccwdev(dev) : NULL;
1077 }
1078
1079 /************************** device driver handling ************************/
1080
1081 /* This is the implementation of the ccw_driver class. The probe, remove
1082  * and release methods are initially very similar to the device_driver
1083  * implementations, with the difference that they have ccw_device
1084  * arguments.
1085  *
1086  * A ccw driver also contains the information that is needed for
1087  * device matching.
1088  */
1089 static int
1090 ccw_device_probe (struct device *dev)
1091 {
1092         struct ccw_device *cdev = to_ccwdev(dev);
1093         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1094         int ret;
1095
1096         cdev->drv = cdrv; /* to let the driver call _set_online */
1097
1098         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1099
1100         if (ret) {
1101                 cdev->drv = NULL;
1102                 return ret;
1103         }
1104
1105         return 0;
1106 }
1107
1108 static int
1109 ccw_device_remove (struct device *dev)
1110 {
1111         struct ccw_device *cdev = to_ccwdev(dev);
1112         struct ccw_driver *cdrv = cdev->drv;
1113         int ret;
1114
1115         pr_debug("removing device %s\n", cdev->dev.bus_id);
1116         if (cdrv->remove)
1117                 cdrv->remove(cdev);
1118         if (cdev->online) {
1119                 cdev->online = 0;
1120                 spin_lock_irq(cdev->ccwlock);
1121                 ret = ccw_device_offline(cdev);
1122                 spin_unlock_irq(cdev->ccwlock);
1123                 if (ret == 0)
1124                         wait_event(cdev->private->wait_q,
1125                                    dev_fsm_final_state(cdev));
1126                 else
1127                         //FIXME: we can't fail!
1128                         pr_debug("ccw_device_offline returned %d, device %s\n",
1129                                  ret, cdev->dev.bus_id);
1130         }
1131         ccw_device_set_timeout(cdev, 0);
1132         cdev->drv = NULL;
1133         return 0;
1134 }
1135
1136 struct bus_type ccw_bus_type = {
1137         .name   = "ccw",
1138         .match  = ccw_bus_match,
1139         .uevent = ccw_uevent,
1140         .probe  = ccw_device_probe,
1141         .remove = ccw_device_remove,
1142 };
1143
1144 int
1145 ccw_driver_register (struct ccw_driver *cdriver)
1146 {
1147         struct device_driver *drv = &cdriver->driver;
1148
1149         drv->bus = &ccw_bus_type;
1150         drv->name = cdriver->name;
1151
1152         return driver_register(drv);
1153 }
1154
1155 void
1156 ccw_driver_unregister (struct ccw_driver *cdriver)
1157 {
1158         driver_unregister(&cdriver->driver);
1159 }
1160
1161 /* Helper func for qdio. */
1162 struct subchannel_id
1163 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1164 {
1165         struct subchannel *sch;
1166
1167         sch = to_subchannel(cdev->dev.parent);
1168         return sch->schid;
1169 }
1170
1171 MODULE_LICENSE("GPL");
1172 EXPORT_SYMBOL(ccw_device_set_online);
1173 EXPORT_SYMBOL(ccw_device_set_offline);
1174 EXPORT_SYMBOL(ccw_driver_register);
1175 EXPORT_SYMBOL(ccw_driver_unregister);
1176 EXPORT_SYMBOL(get_ccwdev_by_busid);
1177 EXPORT_SYMBOL(ccw_bus_type);
1178 EXPORT_SYMBOL(ccw_device_work);
1179 EXPORT_SYMBOL(ccw_device_notify_work);
1180 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);