2 * drivers/s390/cio/device.c
3 * bus driver for ccw devices
5 * Copyright IBM Corp. 2002,2008
6 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
7 * Cornelia Huck (cornelia.huck@de.ibm.com)
8 * Martin Schwidefsky (schwidefsky@de.ibm.com)
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/spinlock.h>
13 #include <linux/errno.h>
14 #include <linux/err.h>
15 #include <linux/slab.h>
16 #include <linux/list.h>
17 #include <linux/device.h>
18 #include <linux/workqueue.h>
19 #include <linux/timer.h>
21 #include <asm/ccwdev.h>
23 #include <asm/param.h> /* HZ */
29 #include "cio_debug.h"
34 #include "blacklist.h"
36 static struct timer_list recovery_timer;
37 static DEFINE_SPINLOCK(recovery_lock);
38 static int recovery_phase;
39 static const unsigned long recovery_delay[] = { 3, 30, 300 };
41 /******************* bus type handling ***********************/
43 /* The Linux driver model distinguishes between a bus type and
44 * the bus itself. Of course we only have one channel
45 * subsystem driver and one channel system per machine, but
46 * we still use the abstraction. T.R. says it's a good idea. */
48 ccw_bus_match (struct device * dev, struct device_driver * drv)
50 struct ccw_device *cdev = to_ccwdev(dev);
51 struct ccw_driver *cdrv = to_ccwdrv(drv);
52 const struct ccw_device_id *ids = cdrv->ids, *found;
57 found = ccw_device_id_match(ids, &cdev->id);
61 cdev->id.driver_info = found->driver_info;
66 /* Store modalias string delimited by prefix/suffix string into buffer with
67 * specified size. Return length of resulting string (excluding trailing '\0')
68 * even if string doesn't fit buffer (snprintf semantics). */
69 static int snprint_alias(char *buf, size_t size,
70 struct ccw_device_id *id, const char *suffix)
74 len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
80 if (id->dev_type != 0)
81 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
82 id->dev_model, suffix);
84 len += snprintf(buf, size, "dtdm%s", suffix);
89 /* Set up environment variables for ccw device uevent. Return 0 on success,
90 * non-zero otherwise. */
91 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
93 struct ccw_device *cdev = to_ccwdev(dev);
94 struct ccw_device_id *id = &(cdev->id);
96 char modalias_buf[30];
99 ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
104 ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
108 /* The next two can be zero, that's ok for us */
110 ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
115 ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
120 snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
121 ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
125 struct bus_type ccw_bus_type;
127 static void io_subchannel_irq(struct subchannel *);
128 static int io_subchannel_probe(struct subchannel *);
129 static int io_subchannel_remove(struct subchannel *);
130 static void io_subchannel_shutdown(struct subchannel *);
131 static int io_subchannel_sch_event(struct subchannel *, int);
132 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
135 static struct css_device_id io_subchannel_ids[] = {
136 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
137 { /* end of list */ },
139 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
141 static struct css_driver io_subchannel_driver = {
142 .owner = THIS_MODULE,
143 .subchannel_type = io_subchannel_ids,
144 .name = "io_subchannel",
145 .irq = io_subchannel_irq,
146 .sch_event = io_subchannel_sch_event,
147 .chp_event = io_subchannel_chp_event,
148 .probe = io_subchannel_probe,
149 .remove = io_subchannel_remove,
150 .shutdown = io_subchannel_shutdown,
153 struct workqueue_struct *ccw_device_work;
154 wait_queue_head_t ccw_device_init_wq;
155 atomic_t ccw_device_init_count;
157 static void recovery_func(unsigned long data);
160 init_ccw_bus_type (void)
164 init_waitqueue_head(&ccw_device_init_wq);
165 atomic_set(&ccw_device_init_count, 0);
166 setup_timer(&recovery_timer, recovery_func, 0);
168 ccw_device_work = create_singlethread_workqueue("cio");
169 if (!ccw_device_work)
170 return -ENOMEM; /* FIXME: better errno ? */
171 slow_path_wq = create_singlethread_workqueue("kslowcrw");
173 ret = -ENOMEM; /* FIXME: better errno ? */
176 if ((ret = bus_register (&ccw_bus_type)))
179 ret = css_driver_register(&io_subchannel_driver);
183 wait_event(ccw_device_init_wq,
184 atomic_read(&ccw_device_init_count) == 0);
185 flush_workqueue(ccw_device_work);
189 destroy_workqueue(ccw_device_work);
191 destroy_workqueue(slow_path_wq);
196 cleanup_ccw_bus_type (void)
198 css_driver_unregister(&io_subchannel_driver);
199 bus_unregister(&ccw_bus_type);
200 destroy_workqueue(ccw_device_work);
203 subsys_initcall(init_ccw_bus_type);
204 module_exit(cleanup_ccw_bus_type);
206 /************************ device handling **************************/
209 * A ccw_device has some interfaces in sysfs in addition to the
211 * The following entries are designed to export the information which
212 * resided in 2.4 in /proc/subchannels. Subchannel and device number
213 * are obvious, so they don't have an entry :)
214 * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
217 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
219 struct subchannel *sch = to_subchannel(dev);
220 struct chsc_ssd_info *ssd = &sch->ssd_info;
225 for (chp = 0; chp < 8; chp++) {
227 if (ssd->path_mask & mask)
228 ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
230 ret += sprintf(buf + ret, "00 ");
232 ret += sprintf (buf+ret, "\n");
233 return min((ssize_t)PAGE_SIZE, ret);
237 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
239 struct subchannel *sch = to_subchannel(dev);
240 struct pmcw *pmcw = &sch->schib.pmcw;
242 return sprintf (buf, "%02x %02x %02x\n",
243 pmcw->pim, pmcw->pam, pmcw->pom);
247 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
249 struct ccw_device *cdev = to_ccwdev(dev);
250 struct ccw_device_id *id = &(cdev->id);
252 if (id->dev_type != 0)
253 return sprintf(buf, "%04x/%02x\n",
254 id->dev_type, id->dev_model);
256 return sprintf(buf, "n/a\n");
260 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
262 struct ccw_device *cdev = to_ccwdev(dev);
263 struct ccw_device_id *id = &(cdev->id);
265 return sprintf(buf, "%04x/%02x\n",
266 id->cu_type, id->cu_model);
270 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
272 struct ccw_device *cdev = to_ccwdev(dev);
273 struct ccw_device_id *id = &(cdev->id);
276 len = snprint_alias(buf, PAGE_SIZE, id, "\n");
278 return len > PAGE_SIZE ? PAGE_SIZE : len;
282 online_show (struct device *dev, struct device_attribute *attr, char *buf)
284 struct ccw_device *cdev = to_ccwdev(dev);
286 return sprintf(buf, cdev->online ? "1\n" : "0\n");
289 int ccw_device_is_orphan(struct ccw_device *cdev)
291 return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
294 static void ccw_device_unregister(struct ccw_device *cdev)
296 if (test_and_clear_bit(1, &cdev->private->registered))
297 device_del(&cdev->dev);
300 static void ccw_device_remove_orphan_cb(struct work_struct *work)
302 struct ccw_device_private *priv;
303 struct ccw_device *cdev;
305 priv = container_of(work, struct ccw_device_private, kick_work);
307 ccw_device_unregister(cdev);
308 put_device(&cdev->dev);
309 /* Release cdev reference for workqueue processing. */
310 put_device(&cdev->dev);
313 static void ccw_device_call_sch_unregister(struct work_struct *work);
316 ccw_device_remove_disconnected(struct ccw_device *cdev)
321 * Forced offline in disconnected state means
322 * 'throw away device'.
324 /* Get cdev reference for workqueue processing. */
325 if (!get_device(&cdev->dev))
327 if (ccw_device_is_orphan(cdev)) {
329 * Deregister ccw device.
330 * Unfortunately, we cannot do this directly from the
333 spin_lock_irqsave(cdev->ccwlock, flags);
334 cdev->private->state = DEV_STATE_NOT_OPER;
335 spin_unlock_irqrestore(cdev->ccwlock, flags);
336 PREPARE_WORK(&cdev->private->kick_work,
337 ccw_device_remove_orphan_cb);
339 /* Deregister subchannel, which will kill the ccw device. */
340 PREPARE_WORK(&cdev->private->kick_work,
341 ccw_device_call_sch_unregister);
342 queue_work(slow_path_wq, &cdev->private->kick_work);
346 * ccw_device_set_offline() - disable a ccw device for I/O
347 * @cdev: target ccw device
349 * This function calls the driver's set_offline() function for @cdev, if
350 * given, and then disables @cdev.
352 * %0 on success and a negative error value on failure.
354 * enabled, ccw device lock not held
356 int ccw_device_set_offline(struct ccw_device *cdev)
362 if (!cdev->online || !cdev->drv)
365 if (cdev->drv->set_offline) {
366 ret = cdev->drv->set_offline(cdev);
371 spin_lock_irq(cdev->ccwlock);
372 ret = ccw_device_offline(cdev);
373 if (ret == -ENODEV) {
374 if (cdev->private->state != DEV_STATE_NOT_OPER) {
375 cdev->private->state = DEV_STATE_OFFLINE;
376 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
378 spin_unlock_irq(cdev->ccwlock);
381 spin_unlock_irq(cdev->ccwlock);
383 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
385 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
386 "device 0.%x.%04x\n",
387 ret, cdev->private->dev_id.ssid,
388 cdev->private->dev_id.devno);
395 * ccw_device_set_online() - enable a ccw device for I/O
396 * @cdev: target ccw device
398 * This function first enables @cdev and then calls the driver's set_online()
399 * function for @cdev, if given. If set_online() returns an error, @cdev is
402 * %0 on success and a negative error value on failure.
404 * enabled, ccw device lock not held
406 int ccw_device_set_online(struct ccw_device *cdev)
412 if (cdev->online || !cdev->drv)
415 spin_lock_irq(cdev->ccwlock);
416 ret = ccw_device_online(cdev);
417 spin_unlock_irq(cdev->ccwlock);
419 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
421 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
422 "device 0.%x.%04x\n",
423 ret, cdev->private->dev_id.ssid,
424 cdev->private->dev_id.devno);
427 if (cdev->private->state != DEV_STATE_ONLINE)
429 if (!cdev->drv->set_online || cdev->drv->set_online(cdev) == 0) {
433 spin_lock_irq(cdev->ccwlock);
434 ret = ccw_device_offline(cdev);
435 spin_unlock_irq(cdev->ccwlock);
437 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
439 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
440 "device 0.%x.%04x\n",
441 ret, cdev->private->dev_id.ssid,
442 cdev->private->dev_id.devno);
443 return (ret == 0) ? -ENODEV : ret;
446 static void online_store_handle_offline(struct ccw_device *cdev)
448 if (cdev->private->state == DEV_STATE_DISCONNECTED)
449 ccw_device_remove_disconnected(cdev);
450 else if (cdev->drv && cdev->drv->set_offline)
451 ccw_device_set_offline(cdev);
454 static int online_store_recog_and_online(struct ccw_device *cdev)
458 /* Do device recognition, if needed. */
459 if (cdev->id.cu_type == 0) {
460 ret = ccw_device_recognition(cdev);
462 CIO_MSG_EVENT(0, "Couldn't start recognition "
463 "for device 0.%x.%04x (ret=%d)\n",
464 cdev->private->dev_id.ssid,
465 cdev->private->dev_id.devno, ret);
468 wait_event(cdev->private->wait_q,
469 cdev->private->flags.recog_done);
471 if (cdev->drv && cdev->drv->set_online)
472 ccw_device_set_online(cdev);
475 static int online_store_handle_online(struct ccw_device *cdev, int force)
479 ret = online_store_recog_and_online(cdev);
482 if (force && cdev->private->state == DEV_STATE_BOXED) {
483 ret = ccw_device_stlck(cdev);
486 if (cdev->id.cu_type == 0)
487 cdev->private->state = DEV_STATE_NOT_OPER;
488 online_store_recog_and_online(cdev);
493 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
494 const char *buf, size_t count)
496 struct ccw_device *cdev = to_ccwdev(dev);
500 if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
503 if (cdev->drv && !try_module_get(cdev->drv->owner)) {
504 atomic_set(&cdev->private->onoff, 0);
507 if (!strncmp(buf, "force\n", count)) {
513 ret = strict_strtoul(buf, 16, &i);
519 online_store_handle_offline(cdev);
523 ret = online_store_handle_online(cdev, force);
532 module_put(cdev->drv->owner);
533 atomic_set(&cdev->private->onoff, 0);
538 available_show (struct device *dev, struct device_attribute *attr, char *buf)
540 struct ccw_device *cdev = to_ccwdev(dev);
541 struct subchannel *sch;
543 if (ccw_device_is_orphan(cdev))
544 return sprintf(buf, "no device\n");
545 switch (cdev->private->state) {
546 case DEV_STATE_BOXED:
547 return sprintf(buf, "boxed\n");
548 case DEV_STATE_DISCONNECTED:
549 case DEV_STATE_DISCONNECTED_SENSE_ID:
550 case DEV_STATE_NOT_OPER:
551 sch = to_subchannel(dev->parent);
553 return sprintf(buf, "no path\n");
555 return sprintf(buf, "no device\n");
557 /* All other states considered fine. */
558 return sprintf(buf, "good\n");
562 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
563 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
564 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
565 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
566 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
567 static DEVICE_ATTR(online, 0644, online_show, online_store);
568 static DEVICE_ATTR(availability, 0444, available_show, NULL);
570 static struct attribute *io_subchannel_attrs[] = {
571 &dev_attr_chpids.attr,
572 &dev_attr_pimpampom.attr,
576 static struct attribute_group io_subchannel_attr_group = {
577 .attrs = io_subchannel_attrs,
580 static struct attribute * ccwdev_attrs[] = {
581 &dev_attr_devtype.attr,
582 &dev_attr_cutype.attr,
583 &dev_attr_modalias.attr,
584 &dev_attr_online.attr,
585 &dev_attr_cmb_enable.attr,
586 &dev_attr_availability.attr,
590 static struct attribute_group ccwdev_attr_group = {
591 .attrs = ccwdev_attrs,
594 static struct attribute_group *ccwdev_attr_groups[] = {
599 /* this is a simple abstraction for device_register that sets the
600 * correct bus type and adds the bus specific files */
601 static int ccw_device_register(struct ccw_device *cdev)
603 struct device *dev = &cdev->dev;
606 dev->bus = &ccw_bus_type;
608 if ((ret = device_add(dev)))
611 set_bit(1, &cdev->private->registered);
616 struct ccw_dev_id dev_id;
617 struct ccw_device * sibling;
621 match_devno(struct device * dev, void * data)
623 struct match_data * d = data;
624 struct ccw_device * cdev;
626 cdev = to_ccwdev(dev);
627 if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
628 !ccw_device_is_orphan(cdev) &&
629 ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) &&
630 (cdev != d->sibling))
635 static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id,
636 struct ccw_device *sibling)
639 struct match_data data;
641 data.dev_id = *dev_id;
642 data.sibling = sibling;
643 dev = bus_find_device(&ccw_bus_type, NULL, &data, match_devno);
645 return dev ? to_ccwdev(dev) : NULL;
648 static int match_orphan(struct device *dev, void *data)
650 struct ccw_dev_id *dev_id;
651 struct ccw_device *cdev;
654 cdev = to_ccwdev(dev);
655 return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
658 static struct ccw_device *
659 get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css,
660 struct ccw_dev_id *dev_id)
664 dev = device_find_child(&css->pseudo_subchannel->dev, dev_id,
667 return dev ? to_ccwdev(dev) : NULL;
671 ccw_device_add_changed(struct work_struct *work)
673 struct ccw_device_private *priv;
674 struct ccw_device *cdev;
676 priv = container_of(work, struct ccw_device_private, kick_work);
678 if (device_add(&cdev->dev)) {
679 put_device(&cdev->dev);
682 set_bit(1, &cdev->private->registered);
685 void ccw_device_do_unreg_rereg(struct work_struct *work)
687 struct ccw_device_private *priv;
688 struct ccw_device *cdev;
689 struct subchannel *sch;
691 priv = container_of(work, struct ccw_device_private, kick_work);
693 sch = to_subchannel(cdev->dev.parent);
695 ccw_device_unregister(cdev);
696 PREPARE_WORK(&cdev->private->kick_work,
697 ccw_device_add_changed);
698 queue_work(ccw_device_work, &cdev->private->kick_work);
702 ccw_device_release(struct device *dev)
704 struct ccw_device *cdev;
706 cdev = to_ccwdev(dev);
707 kfree(cdev->private);
711 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
713 struct ccw_device *cdev;
715 cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
717 cdev->private = kzalloc(sizeof(struct ccw_device_private),
718 GFP_KERNEL | GFP_DMA);
723 return ERR_PTR(-ENOMEM);
726 static int io_subchannel_initialize_dev(struct subchannel *sch,
727 struct ccw_device *cdev)
729 cdev->private->cdev = cdev;
730 atomic_set(&cdev->private->onoff, 0);
731 cdev->dev.parent = &sch->dev;
732 cdev->dev.release = ccw_device_release;
733 INIT_WORK(&cdev->private->kick_work, NULL);
734 cdev->dev.groups = ccwdev_attr_groups;
735 /* Do first half of device_register. */
736 device_initialize(&cdev->dev);
737 if (!get_device(&sch->dev)) {
738 if (cdev->dev.release)
739 cdev->dev.release(&cdev->dev);
745 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
747 struct ccw_device *cdev;
750 cdev = io_subchannel_allocate_dev(sch);
752 ret = io_subchannel_initialize_dev(sch, cdev);
761 static int io_subchannel_recog(struct ccw_device *, struct subchannel *);
763 static void sch_attach_device(struct subchannel *sch,
764 struct ccw_device *cdev)
766 css_update_ssd_info(sch);
767 spin_lock_irq(sch->lock);
768 sch_set_cdev(sch, cdev);
769 cdev->private->schid = sch->schid;
770 cdev->ccwlock = sch->lock;
771 ccw_device_trigger_reprobe(cdev);
772 spin_unlock_irq(sch->lock);
775 static void sch_attach_disconnected_device(struct subchannel *sch,
776 struct ccw_device *cdev)
778 struct subchannel *other_sch;
781 other_sch = to_subchannel(get_device(cdev->dev.parent));
782 ret = device_move(&cdev->dev, &sch->dev);
784 CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "
785 "(ret=%d)!\n", cdev->private->dev_id.ssid,
786 cdev->private->dev_id.devno, ret);
787 put_device(&other_sch->dev);
790 sch_set_cdev(other_sch, NULL);
791 /* No need to keep a subchannel without ccw device around. */
792 css_sch_device_unregister(other_sch);
793 put_device(&other_sch->dev);
794 sch_attach_device(sch, cdev);
797 static void sch_attach_orphaned_device(struct subchannel *sch,
798 struct ccw_device *cdev)
802 /* Try to move the ccw device to its new subchannel. */
803 ret = device_move(&cdev->dev, &sch->dev);
805 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "
806 "failed (ret=%d)!\n",
807 cdev->private->dev_id.ssid,
808 cdev->private->dev_id.devno, ret);
811 sch_attach_device(sch, cdev);
814 static void sch_create_and_recog_new_device(struct subchannel *sch)
816 struct ccw_device *cdev;
818 /* Need to allocate a new ccw device. */
819 cdev = io_subchannel_create_ccwdev(sch);
821 /* OK, we did everything we could... */
822 css_sch_device_unregister(sch);
825 spin_lock_irq(sch->lock);
826 sch_set_cdev(sch, cdev);
827 spin_unlock_irq(sch->lock);
828 /* Start recognition for the new ccw device. */
829 if (io_subchannel_recog(cdev, sch)) {
830 spin_lock_irq(sch->lock);
831 sch_set_cdev(sch, NULL);
832 spin_unlock_irq(sch->lock);
833 if (cdev->dev.release)
834 cdev->dev.release(&cdev->dev);
835 css_sch_device_unregister(sch);
840 void ccw_device_move_to_orphanage(struct work_struct *work)
842 struct ccw_device_private *priv;
843 struct ccw_device *cdev;
844 struct ccw_device *replacing_cdev;
845 struct subchannel *sch;
847 struct channel_subsystem *css;
848 struct ccw_dev_id dev_id;
850 priv = container_of(work, struct ccw_device_private, kick_work);
852 sch = to_subchannel(cdev->dev.parent);
853 css = to_css(sch->dev.parent);
854 dev_id.devno = sch->schib.pmcw.dev;
855 dev_id.ssid = sch->schid.ssid;
858 * Move the orphaned ccw device to the orphanage so the replacing
859 * ccw device can take its place on the subchannel.
861 ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);
863 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "
864 "(ret=%d)!\n", cdev->private->dev_id.ssid,
865 cdev->private->dev_id.devno, ret);
868 cdev->ccwlock = css->pseudo_subchannel->lock;
870 * Search for the replacing ccw device
871 * - among the disconnected devices
874 replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev);
875 if (replacing_cdev) {
876 sch_attach_disconnected_device(sch, replacing_cdev);
879 replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id);
880 if (replacing_cdev) {
881 sch_attach_orphaned_device(sch, replacing_cdev);
884 sch_create_and_recog_new_device(sch);
888 * Register recognized device.
891 io_subchannel_register(struct work_struct *work)
893 struct ccw_device_private *priv;
894 struct ccw_device *cdev;
895 struct subchannel *sch;
899 priv = container_of(work, struct ccw_device_private, kick_work);
901 sch = to_subchannel(cdev->dev.parent);
902 css_update_ssd_info(sch);
904 * io_subchannel_register() will also be called after device
905 * recognition has been done for a boxed device (which will already
906 * be registered). We need to reprobe since we may now have sense id
909 if (klist_node_attached(&cdev->dev.knode_parent)) {
911 ret = device_reprobe(&cdev->dev);
913 /* We can't do much here. */
914 CIO_MSG_EVENT(0, "device_reprobe() returned"
915 " %d for 0.%x.%04x\n", ret,
916 cdev->private->dev_id.ssid,
917 cdev->private->dev_id.devno);
922 * Now we know this subchannel will stay, we can throw
923 * our delayed uevent.
925 sch->dev.uevent_suppress = 0;
926 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
927 /* make it known to the system */
928 ret = ccw_device_register(cdev);
930 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
931 cdev->private->dev_id.ssid,
932 cdev->private->dev_id.devno, ret);
933 put_device(&cdev->dev);
934 spin_lock_irqsave(sch->lock, flags);
935 sch_set_cdev(sch, NULL);
936 spin_unlock_irqrestore(sch->lock, flags);
937 kfree (cdev->private);
939 put_device(&sch->dev);
940 if (atomic_dec_and_test(&ccw_device_init_count))
941 wake_up(&ccw_device_init_wq);
944 put_device(&cdev->dev);
946 cdev->private->flags.recog_done = 1;
947 put_device(&sch->dev);
948 wake_up(&cdev->private->wait_q);
949 if (atomic_dec_and_test(&ccw_device_init_count))
950 wake_up(&ccw_device_init_wq);
953 static void ccw_device_call_sch_unregister(struct work_struct *work)
955 struct ccw_device_private *priv;
956 struct ccw_device *cdev;
957 struct subchannel *sch;
959 priv = container_of(work, struct ccw_device_private, kick_work);
961 /* Get subchannel reference for local processing. */
962 if (!get_device(cdev->dev.parent))
964 sch = to_subchannel(cdev->dev.parent);
965 css_sch_device_unregister(sch);
966 /* Reset intparm to zeroes. */
967 sch->schib.pmcw.intparm = 0;
969 /* Release cdev reference for workqueue processing.*/
970 put_device(&cdev->dev);
971 /* Release subchannel reference for local processing. */
972 put_device(&sch->dev);
976 * subchannel recognition done. Called from the state machine.
979 io_subchannel_recog_done(struct ccw_device *cdev)
981 struct subchannel *sch;
983 if (css_init_done == 0) {
984 cdev->private->flags.recog_done = 1;
987 switch (cdev->private->state) {
988 case DEV_STATE_NOT_OPER:
989 cdev->private->flags.recog_done = 1;
990 /* Remove device found not operational. */
991 if (!get_device(&cdev->dev))
993 sch = to_subchannel(cdev->dev.parent);
994 PREPARE_WORK(&cdev->private->kick_work,
995 ccw_device_call_sch_unregister);
996 queue_work(slow_path_wq, &cdev->private->kick_work);
997 /* Release subchannel reference for asynchronous recognition. */
998 put_device(&sch->dev);
999 if (atomic_dec_and_test(&ccw_device_init_count))
1000 wake_up(&ccw_device_init_wq);
1002 case DEV_STATE_BOXED:
1003 /* Device did not respond in time. */
1004 case DEV_STATE_OFFLINE:
1006 * We can't register the device in interrupt context so
1007 * we schedule a work item.
1009 if (!get_device(&cdev->dev))
1011 PREPARE_WORK(&cdev->private->kick_work,
1012 io_subchannel_register);
1013 queue_work(slow_path_wq, &cdev->private->kick_work);
1019 io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
1022 struct ccw_device_private *priv;
1024 sch_set_cdev(sch, cdev);
1025 cdev->ccwlock = sch->lock;
1027 /* Init private data. */
1028 priv = cdev->private;
1029 priv->dev_id.devno = sch->schib.pmcw.dev;
1030 priv->dev_id.ssid = sch->schid.ssid;
1031 priv->schid = sch->schid;
1032 priv->state = DEV_STATE_NOT_OPER;
1033 INIT_LIST_HEAD(&priv->cmb_list);
1034 init_waitqueue_head(&priv->wait_q);
1035 init_timer(&priv->timer);
1037 /* Set an initial name for the device. */
1038 snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x",
1039 sch->schid.ssid, sch->schib.pmcw.dev);
1041 /* Increase counter of devices currently in recognition. */
1042 atomic_inc(&ccw_device_init_count);
1044 /* Start async. device sensing. */
1045 spin_lock_irq(sch->lock);
1046 rc = ccw_device_recognition(cdev);
1047 spin_unlock_irq(sch->lock);
1049 if (atomic_dec_and_test(&ccw_device_init_count))
1050 wake_up(&ccw_device_init_wq);
1055 static void ccw_device_move_to_sch(struct work_struct *work)
1057 struct ccw_device_private *priv;
1059 struct subchannel *sch;
1060 struct ccw_device *cdev;
1061 struct subchannel *former_parent;
1063 priv = container_of(work, struct ccw_device_private, kick_work);
1066 former_parent = ccw_device_is_orphan(cdev) ?
1067 NULL : to_subchannel(get_device(cdev->dev.parent));
1068 mutex_lock(&sch->reg_mutex);
1069 /* Try to move the ccw device to its new subchannel. */
1070 rc = device_move(&cdev->dev, &sch->dev);
1071 mutex_unlock(&sch->reg_mutex);
1073 CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "
1074 "0.%x.%04x failed (ret=%d)!\n",
1075 cdev->private->dev_id.ssid,
1076 cdev->private->dev_id.devno, sch->schid.ssid,
1077 sch->schid.sch_no, rc);
1078 css_sch_device_unregister(sch);
1081 if (former_parent) {
1082 spin_lock_irq(former_parent->lock);
1083 sch_set_cdev(former_parent, NULL);
1084 spin_unlock_irq(former_parent->lock);
1085 css_sch_device_unregister(former_parent);
1086 /* Reset intparm to zeroes. */
1087 former_parent->schib.pmcw.intparm = 0;
1088 cio_modify(former_parent);
1090 sch_attach_device(sch, cdev);
1093 put_device(&former_parent->dev);
1094 put_device(&cdev->dev);
1097 static void io_subchannel_irq(struct subchannel *sch)
1099 struct ccw_device *cdev;
1101 cdev = sch_get_cdev(sch);
1103 CIO_TRACE_EVENT(3, "IRQ");
1104 CIO_TRACE_EVENT(3, dev_name(&sch->dev));
1106 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1109 static void io_subchannel_init_fields(struct subchannel *sch)
1111 if (cio_is_console(sch->schid))
1114 sch->opm = chp_get_sch_opm(sch);
1115 sch->lpm = sch->schib.pmcw.pam & sch->opm;
1116 sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1118 CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1119 " - PIM = %02X, PAM = %02X, POM = %02X\n",
1120 sch->schib.pmcw.dev, sch->schid.ssid,
1121 sch->schid.sch_no, sch->schib.pmcw.pim,
1122 sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1123 /* Initially set up some fields in the pmcw. */
1124 sch->schib.pmcw.ena = 0;
1125 sch->schib.pmcw.csense = 1; /* concurrent sense */
1126 if ((sch->lpm & (sch->lpm - 1)) != 0)
1127 sch->schib.pmcw.mp = 1; /* multipath mode */
1128 /* clean up possible residual cmf stuff */
1129 sch->schib.pmcw.mme = 0;
1130 sch->schib.pmcw.mbfc = 0;
1131 sch->schib.pmcw.mbi = 0;
1135 static int io_subchannel_probe(struct subchannel *sch)
1137 struct ccw_device *cdev;
1139 unsigned long flags;
1140 struct ccw_dev_id dev_id;
1142 cdev = sch_get_cdev(sch);
1144 rc = sysfs_create_group(&sch->dev.kobj,
1145 &io_subchannel_attr_group);
1147 CIO_MSG_EVENT(0, "Failed to create io subchannel "
1148 "attributes for subchannel "
1149 "0.%x.%04x (rc=%d)\n",
1150 sch->schid.ssid, sch->schid.sch_no, rc);
1152 * This subchannel already has an associated ccw_device.
1153 * Throw the delayed uevent for the subchannel, register
1154 * the ccw_device and exit. This happens for all early
1155 * devices, e.g. the console.
1157 sch->dev.uevent_suppress = 0;
1158 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1159 cdev->dev.groups = ccwdev_attr_groups;
1160 device_initialize(&cdev->dev);
1161 ccw_device_register(cdev);
1163 * Check if the device is already online. If it is
1164 * the reference count needs to be corrected
1165 * (see ccw_device_online and css_init_done for the
1168 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1169 cdev->private->state != DEV_STATE_OFFLINE &&
1170 cdev->private->state != DEV_STATE_BOXED)
1171 get_device(&cdev->dev);
1174 io_subchannel_init_fields(sch);
1176 * First check if a fitting device may be found amongst the
1177 * disconnected devices or in the orphanage.
1179 dev_id.devno = sch->schib.pmcw.dev;
1180 dev_id.ssid = sch->schid.ssid;
1181 rc = sysfs_create_group(&sch->dev.kobj,
1182 &io_subchannel_attr_group);
1185 /* Allocate I/O subchannel private data. */
1186 sch->private = kzalloc(sizeof(struct io_subchannel_private),
1187 GFP_KERNEL | GFP_DMA);
1188 if (!sch->private) {
1192 cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL);
1194 cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent),
1198 * Schedule moving the device until when we have a registered
1199 * subchannel to move to and succeed the probe. We can
1200 * unregister later again, when the probe is through.
1202 cdev->private->sch = sch;
1203 PREPARE_WORK(&cdev->private->kick_work,
1204 ccw_device_move_to_sch);
1205 queue_work(slow_path_wq, &cdev->private->kick_work);
1208 cdev = io_subchannel_create_ccwdev(sch);
1213 rc = io_subchannel_recog(cdev, sch);
1215 spin_lock_irqsave(sch->lock, flags);
1216 sch_set_cdev(sch, NULL);
1217 spin_unlock_irqrestore(sch->lock, flags);
1218 if (cdev->dev.release)
1219 cdev->dev.release(&cdev->dev);
1224 kfree(sch->private);
1225 sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1230 io_subchannel_remove (struct subchannel *sch)
1232 struct ccw_device *cdev;
1233 unsigned long flags;
1235 cdev = sch_get_cdev(sch);
1238 /* Set ccw device to not operational and drop reference. */
1239 spin_lock_irqsave(cdev->ccwlock, flags);
1240 sch_set_cdev(sch, NULL);
1241 cdev->private->state = DEV_STATE_NOT_OPER;
1242 spin_unlock_irqrestore(cdev->ccwlock, flags);
1243 ccw_device_unregister(cdev);
1244 put_device(&cdev->dev);
1245 kfree(sch->private);
1246 sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1250 static int io_subchannel_notify(struct subchannel *sch, int event)
1252 struct ccw_device *cdev;
1254 cdev = sch_get_cdev(sch);
1257 return ccw_device_notify(cdev, event);
1260 static void io_subchannel_verify(struct subchannel *sch)
1262 struct ccw_device *cdev;
1264 cdev = sch_get_cdev(sch);
1266 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1269 static int check_for_io_on_path(struct subchannel *sch, int mask)
1273 cc = stsch(sch->schid, &sch->schib);
1276 if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
1281 static void terminate_internal_io(struct subchannel *sch,
1282 struct ccw_device *cdev)
1284 if (cio_clear(sch)) {
1285 /* Recheck device in case clear failed. */
1288 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1290 css_schedule_eval(sch->schid);
1293 cdev->private->state = DEV_STATE_CLEAR_VERIFY;
1294 /* Request retry of internal operation. */
1295 cdev->private->flags.intretry = 1;
1298 cdev->handler(cdev, cdev->private->intparm,
1302 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1304 struct ccw_device *cdev;
1306 cdev = sch_get_cdev(sch);
1309 if (check_for_io_on_path(sch, mask)) {
1310 if (cdev->private->state == DEV_STATE_ONLINE)
1311 ccw_device_kill_io(cdev);
1313 terminate_internal_io(sch, cdev);
1314 /* Re-start path verification. */
1315 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1318 /* trigger path verification. */
1319 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1323 static int io_subchannel_chp_event(struct subchannel *sch,
1324 struct chp_link *link, int event)
1328 mask = chp_ssd_get_mask(&sch->ssd_info, link);
1335 io_subchannel_terminate_path(sch, mask);
1340 io_subchannel_verify(sch);
1343 if (stsch(sch->schid, &sch->schib))
1345 if (!css_sch_is_valid(&sch->schib))
1347 io_subchannel_terminate_path(sch, mask);
1350 if (stsch(sch->schid, &sch->schib))
1352 sch->lpm |= mask & sch->opm;
1353 io_subchannel_verify(sch);
1360 io_subchannel_shutdown(struct subchannel *sch)
1362 struct ccw_device *cdev;
1365 cdev = sch_get_cdev(sch);
1367 if (cio_is_console(sch->schid))
1369 if (!sch->schib.pmcw.ena)
1370 /* Nothing to do. */
1372 ret = cio_disable_subchannel(sch);
1374 /* Subchannel is disabled, we're done. */
1376 cdev->private->state = DEV_STATE_QUIESCE;
1378 cdev->handler(cdev, cdev->private->intparm,
1380 ret = ccw_device_cancel_halt_clear(cdev);
1381 if (ret == -EBUSY) {
1382 ccw_device_set_timeout(cdev, HZ/10);
1383 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1385 cio_disable_subchannel(sch);
1388 static int io_subchannel_get_status(struct subchannel *sch)
1392 if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
1394 if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
1395 return CIO_REVALIDATE;
1401 static int device_is_disconnected(struct ccw_device *cdev)
1405 return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1406 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1409 static int recovery_check(struct device *dev, void *data)
1411 struct ccw_device *cdev = to_ccwdev(dev);
1414 spin_lock_irq(cdev->ccwlock);
1415 switch (cdev->private->state) {
1416 case DEV_STATE_DISCONNECTED:
1417 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1418 cdev->private->dev_id.ssid,
1419 cdev->private->dev_id.devno);
1420 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1423 case DEV_STATE_DISCONNECTED_SENSE_ID:
1427 spin_unlock_irq(cdev->ccwlock);
1432 static void recovery_work_func(struct work_struct *unused)
1436 bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1438 spin_lock_irq(&recovery_lock);
1439 if (!timer_pending(&recovery_timer)) {
1440 if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1442 mod_timer(&recovery_timer, jiffies +
1443 recovery_delay[recovery_phase] * HZ);
1445 spin_unlock_irq(&recovery_lock);
1447 CIO_MSG_EVENT(4, "recovery: end\n");
1450 static DECLARE_WORK(recovery_work, recovery_work_func);
1452 static void recovery_func(unsigned long data)
1455 * We can't do our recovery in softirq context and it's not
1456 * performance critical, so we schedule it.
1458 schedule_work(&recovery_work);
1461 static void ccw_device_schedule_recovery(void)
1463 unsigned long flags;
1465 CIO_MSG_EVENT(4, "recovery: schedule\n");
1466 spin_lock_irqsave(&recovery_lock, flags);
1467 if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1469 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1471 spin_unlock_irqrestore(&recovery_lock, flags);
1474 static int purge_fn(struct device *dev, void *data)
1476 struct ccw_device *cdev = to_ccwdev(dev);
1477 struct ccw_device_private *priv = cdev->private;
1480 spin_lock_irq(cdev->ccwlock);
1481 unreg = is_blacklisted(priv->dev_id.ssid, priv->dev_id.devno) &&
1482 (priv->state == DEV_STATE_OFFLINE);
1483 spin_unlock_irq(cdev->ccwlock);
1486 if (!get_device(&cdev->dev))
1488 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", priv->dev_id.ssid,
1489 priv->dev_id.devno);
1490 PREPARE_WORK(&cdev->private->kick_work, ccw_device_call_sch_unregister);
1491 queue_work(slow_path_wq, &cdev->private->kick_work);
1494 /* Abort loop in case of pending signal. */
1495 if (signal_pending(current))
1502 * ccw_purge_blacklisted - purge unused, blacklisted devices
1504 * Unregister all ccw devices that are offline and on the blacklist.
1506 int ccw_purge_blacklisted(void)
1508 CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1509 bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1513 static void device_set_disconnected(struct ccw_device *cdev)
1517 ccw_device_set_timeout(cdev, 0);
1518 cdev->private->flags.fake_irb = 0;
1519 cdev->private->state = DEV_STATE_DISCONNECTED;
1521 ccw_device_schedule_recovery();
1524 void ccw_device_set_notoper(struct ccw_device *cdev)
1526 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1528 CIO_TRACE_EVENT(2, "notoper");
1529 CIO_TRACE_EVENT(2, sch->dev.bus_id);
1530 ccw_device_set_timeout(cdev, 0);
1531 cio_disable_subchannel(sch);
1532 cdev->private->state = DEV_STATE_NOT_OPER;
1535 static int io_subchannel_sch_event(struct subchannel *sch, int slow)
1537 int event, ret, disc;
1538 unsigned long flags;
1539 enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE, DISC } action;
1540 struct ccw_device *cdev;
1542 spin_lock_irqsave(sch->lock, flags);
1543 cdev = sch_get_cdev(sch);
1544 disc = device_is_disconnected(cdev);
1546 /* Disconnected devices are evaluated directly only.*/
1547 spin_unlock_irqrestore(sch->lock, flags);
1550 /* No interrupt after machine check - kill pending timers. */
1552 ccw_device_set_timeout(cdev, 0);
1553 if (!disc && !slow) {
1554 /* Non-disconnected devices are evaluated on the slow path. */
1555 spin_unlock_irqrestore(sch->lock, flags);
1558 event = io_subchannel_get_status(sch);
1559 CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
1560 sch->schid.ssid, sch->schid.sch_no, event,
1561 disc ? "disconnected" : "normal",
1562 slow ? "slow" : "fast");
1563 /* Analyze subchannel status. */
1568 /* Check if paths have become available. */
1574 /* Ask driver what to do with device. */
1575 if (io_subchannel_notify(sch, event))
1578 action = UNREGISTER;
1580 case CIO_REVALIDATE:
1581 /* Device will be removed, so no notify necessary. */
1583 /* Reprobe because immediate unregister might block. */
1586 action = UNREGISTER_PROBE;
1590 /* Get device operational again. */
1594 /* Perform action. */
1598 case UNREGISTER_PROBE:
1599 ccw_device_set_notoper(cdev);
1600 /* Unregister device (will use subchannel lock). */
1601 spin_unlock_irqrestore(sch->lock, flags);
1602 css_sch_device_unregister(sch);
1603 spin_lock_irqsave(sch->lock, flags);
1605 /* Reset intparm to zeroes. */
1606 sch->schib.pmcw.intparm = 0;
1610 ccw_device_trigger_reprobe(cdev);
1613 device_set_disconnected(cdev);
1618 spin_unlock_irqrestore(sch->lock, flags);
1619 /* Probe if necessary. */
1620 if (action == UNREGISTER_PROBE)
1621 ret = css_probe_device(sch->schid);
1626 #ifdef CONFIG_CCW_CONSOLE
1627 static struct ccw_device console_cdev;
1628 static struct ccw_device_private console_private;
1629 static int console_cdev_in_use;
1631 static DEFINE_SPINLOCK(ccw_console_lock);
1633 spinlock_t * cio_get_console_lock(void)
1635 return &ccw_console_lock;
1638 static int ccw_device_console_enable(struct ccw_device *cdev,
1639 struct subchannel *sch)
1643 /* Attach subchannel private data. */
1644 sch->private = cio_get_console_priv();
1645 memset(sch->private, 0, sizeof(struct io_subchannel_private));
1646 io_subchannel_init_fields(sch);
1647 sch->driver = &io_subchannel_driver;
1648 /* Initialize the ccw_device structure. */
1649 cdev->dev.parent= &sch->dev;
1650 rc = io_subchannel_recog(cdev, sch);
1654 /* Now wait for the async. recognition to come to an end. */
1655 spin_lock_irq(cdev->ccwlock);
1656 while (!dev_fsm_final_state(cdev))
1659 if (cdev->private->state != DEV_STATE_OFFLINE)
1661 ccw_device_online(cdev);
1662 while (!dev_fsm_final_state(cdev))
1664 if (cdev->private->state != DEV_STATE_ONLINE)
1668 spin_unlock_irq(cdev->ccwlock);
1673 ccw_device_probe_console(void)
1675 struct subchannel *sch;
1678 if (xchg(&console_cdev_in_use, 1) != 0)
1679 return ERR_PTR(-EBUSY);
1680 sch = cio_probe_console();
1682 console_cdev_in_use = 0;
1683 return (void *) sch;
1685 memset(&console_cdev, 0, sizeof(struct ccw_device));
1686 memset(&console_private, 0, sizeof(struct ccw_device_private));
1687 console_cdev.private = &console_private;
1688 console_private.cdev = &console_cdev;
1689 ret = ccw_device_console_enable(&console_cdev, sch);
1691 cio_release_console();
1692 console_cdev_in_use = 0;
1693 return ERR_PTR(ret);
1695 console_cdev.online = 1;
1696 return &console_cdev;
1701 * get ccw_device matching the busid, but only if owned by cdrv
1704 __ccwdev_check_busid(struct device *dev, void *id)
1710 return (strncmp(bus_id, dev_name(dev), BUS_ID_SIZE) == 0);
1715 * get_ccwdev_by_busid() - obtain device from a bus id
1716 * @cdrv: driver the device is owned by
1717 * @bus_id: bus id of the device to be searched
1719 * This function searches all devices owned by @cdrv for a device with a bus
1720 * id matching @bus_id.
1722 * If a match is found, its reference count of the found device is increased
1723 * and it is returned; else %NULL is returned.
1725 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1729 struct device_driver *drv;
1731 drv = get_driver(&cdrv->driver);
1735 dev = driver_find_device(drv, NULL, (void *)bus_id,
1736 __ccwdev_check_busid);
1739 return dev ? to_ccwdev(dev) : NULL;
1742 /************************** device driver handling ************************/
1744 /* This is the implementation of the ccw_driver class. The probe, remove
1745 * and release methods are initially very similar to the device_driver
1746 * implementations, with the difference that they have ccw_device
1749 * A ccw driver also contains the information that is needed for
1753 ccw_device_probe (struct device *dev)
1755 struct ccw_device *cdev = to_ccwdev(dev);
1756 struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1759 cdev->drv = cdrv; /* to let the driver call _set_online */
1761 ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1772 ccw_device_remove (struct device *dev)
1774 struct ccw_device *cdev = to_ccwdev(dev);
1775 struct ccw_driver *cdrv = cdev->drv;
1782 spin_lock_irq(cdev->ccwlock);
1783 ret = ccw_device_offline(cdev);
1784 spin_unlock_irq(cdev->ccwlock);
1786 wait_event(cdev->private->wait_q,
1787 dev_fsm_final_state(cdev));
1789 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1790 "device 0.%x.%04x\n",
1791 ret, cdev->private->dev_id.ssid,
1792 cdev->private->dev_id.devno);
1794 ccw_device_set_timeout(cdev, 0);
1799 static void ccw_device_shutdown(struct device *dev)
1801 struct ccw_device *cdev;
1803 cdev = to_ccwdev(dev);
1804 if (cdev->drv && cdev->drv->shutdown)
1805 cdev->drv->shutdown(cdev);
1809 struct bus_type ccw_bus_type = {
1811 .match = ccw_bus_match,
1812 .uevent = ccw_uevent,
1813 .probe = ccw_device_probe,
1814 .remove = ccw_device_remove,
1815 .shutdown = ccw_device_shutdown,
1819 * ccw_driver_register() - register a ccw driver
1820 * @cdriver: driver to be registered
1822 * This function is mainly a wrapper around driver_register().
1824 * %0 on success and a negative error value on failure.
1826 int ccw_driver_register(struct ccw_driver *cdriver)
1828 struct device_driver *drv = &cdriver->driver;
1830 drv->bus = &ccw_bus_type;
1831 drv->name = cdriver->name;
1832 drv->owner = cdriver->owner;
1834 return driver_register(drv);
1838 * ccw_driver_unregister() - deregister a ccw driver
1839 * @cdriver: driver to be deregistered
1841 * This function is mainly a wrapper around driver_unregister().
1843 void ccw_driver_unregister(struct ccw_driver *cdriver)
1845 driver_unregister(&cdriver->driver);
1848 /* Helper func for qdio. */
1849 struct subchannel_id
1850 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1852 struct subchannel *sch;
1854 sch = to_subchannel(cdev->dev.parent);
1858 MODULE_LICENSE("GPL");
1859 EXPORT_SYMBOL(ccw_device_set_online);
1860 EXPORT_SYMBOL(ccw_device_set_offline);
1861 EXPORT_SYMBOL(ccw_driver_register);
1862 EXPORT_SYMBOL(ccw_driver_unregister);
1863 EXPORT_SYMBOL(get_ccwdev_by_busid);
1864 EXPORT_SYMBOL(ccw_bus_type);
1865 EXPORT_SYMBOL(ccw_device_work);
1866 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);