2 * bus driver for ccw devices
4 * Copyright IBM Corp. 2002, 2008
5 * Author(s): Arnd Bergmann (arndb@de.ibm.com)
6 * Cornelia Huck (cornelia.huck@de.ibm.com)
7 * Martin Schwidefsky (schwidefsky@de.ibm.com)
12 #define KMSG_COMPONENT "cio"
13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15 #include <linux/export.h>
16 #include <linux/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/errno.h>
19 #include <linux/err.h>
20 #include <linux/slab.h>
21 #include <linux/list.h>
22 #include <linux/device.h>
23 #include <linux/workqueue.h>
24 #include <linux/delay.h>
25 #include <linux/timer.h>
26 #include <linux/kernel_stat.h>
28 #include <asm/ccwdev.h>
30 #include <asm/param.h> /* HZ */
36 #include "cio_debug.h"
41 #include "blacklist.h"
44 static struct timer_list recovery_timer;
45 static DEFINE_SPINLOCK(recovery_lock);
46 static int recovery_phase;
47 static const unsigned long recovery_delay[] = { 3, 30, 300 };
49 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
50 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
51 static struct bus_type ccw_bus_type;
53 /******************* bus type handling ***********************/
55 /* The Linux driver model distinguishes between a bus type and
56 * the bus itself. Of course we only have one channel
57 * subsystem driver and one channel system per machine, but
58 * we still use the abstraction. T.R. says it's a good idea. */
60 ccw_bus_match (struct device * dev, struct device_driver * drv)
62 struct ccw_device *cdev = to_ccwdev(dev);
63 struct ccw_driver *cdrv = to_ccwdrv(drv);
64 const struct ccw_device_id *ids = cdrv->ids, *found;
69 found = ccw_device_id_match(ids, &cdev->id);
73 cdev->id.driver_info = found->driver_info;
78 /* Store modalias string delimited by prefix/suffix string into buffer with
79 * specified size. Return length of resulting string (excluding trailing '\0')
80 * even if string doesn't fit buffer (snprintf semantics). */
81 static int snprint_alias(char *buf, size_t size,
82 struct ccw_device_id *id, const char *suffix)
86 len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
92 if (id->dev_type != 0)
93 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
94 id->dev_model, suffix);
96 len += snprintf(buf, size, "dtdm%s", suffix);
101 /* Set up environment variables for ccw device uevent. Return 0 on success,
102 * non-zero otherwise. */
103 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
105 struct ccw_device *cdev = to_ccwdev(dev);
106 struct ccw_device_id *id = &(cdev->id);
108 char modalias_buf[30];
111 ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
116 ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
120 /* The next two can be zero, that's ok for us */
122 ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
127 ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
132 snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
133 ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
137 static void io_subchannel_irq(struct subchannel *);
138 static int io_subchannel_probe(struct subchannel *);
139 static int io_subchannel_remove(struct subchannel *);
140 static void io_subchannel_shutdown(struct subchannel *);
141 static int io_subchannel_sch_event(struct subchannel *, int);
142 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
144 static void recovery_func(unsigned long data);
146 static struct css_device_id io_subchannel_ids[] = {
147 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
148 { /* end of list */ },
151 static int io_subchannel_prepare(struct subchannel *sch)
153 struct ccw_device *cdev;
155 * Don't allow suspend while a ccw device registration
156 * is still outstanding.
158 cdev = sch_get_cdev(sch);
159 if (cdev && !device_is_registered(&cdev->dev))
164 static int io_subchannel_settle(void)
168 ret = wait_event_interruptible(ccw_device_init_wq,
169 atomic_read(&ccw_device_init_count) == 0);
172 flush_workqueue(cio_work_q);
176 static struct css_driver io_subchannel_driver = {
178 .owner = THIS_MODULE,
179 .name = "io_subchannel",
181 .subchannel_type = io_subchannel_ids,
182 .irq = io_subchannel_irq,
183 .sch_event = io_subchannel_sch_event,
184 .chp_event = io_subchannel_chp_event,
185 .probe = io_subchannel_probe,
186 .remove = io_subchannel_remove,
187 .shutdown = io_subchannel_shutdown,
188 .prepare = io_subchannel_prepare,
189 .settle = io_subchannel_settle,
192 int __init io_subchannel_init(void)
196 setup_timer(&recovery_timer, recovery_func, 0);
197 ret = bus_register(&ccw_bus_type);
200 ret = css_driver_register(&io_subchannel_driver);
202 bus_unregister(&ccw_bus_type);
208 /************************ device handling **************************/
211 * A ccw_device has some interfaces in sysfs in addition to the
213 * The following entries are designed to export the information which
214 * resided in 2.4 in /proc/subchannels. Subchannel and device number
215 * are obvious, so they don't have an entry :)
216 * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
219 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
221 struct subchannel *sch = to_subchannel(dev);
222 struct chsc_ssd_info *ssd = &sch->ssd_info;
227 for (chp = 0; chp < 8; chp++) {
229 if (ssd->path_mask & mask)
230 ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
232 ret += sprintf(buf + ret, "00 ");
234 ret += sprintf (buf+ret, "\n");
235 return min((ssize_t)PAGE_SIZE, ret);
239 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
241 struct subchannel *sch = to_subchannel(dev);
242 struct pmcw *pmcw = &sch->schib.pmcw;
244 return sprintf (buf, "%02x %02x %02x\n",
245 pmcw->pim, pmcw->pam, pmcw->pom);
249 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
251 struct ccw_device *cdev = to_ccwdev(dev);
252 struct ccw_device_id *id = &(cdev->id);
254 if (id->dev_type != 0)
255 return sprintf(buf, "%04x/%02x\n",
256 id->dev_type, id->dev_model);
258 return sprintf(buf, "n/a\n");
262 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
264 struct ccw_device *cdev = to_ccwdev(dev);
265 struct ccw_device_id *id = &(cdev->id);
267 return sprintf(buf, "%04x/%02x\n",
268 id->cu_type, id->cu_model);
272 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
274 struct ccw_device *cdev = to_ccwdev(dev);
275 struct ccw_device_id *id = &(cdev->id);
278 len = snprint_alias(buf, PAGE_SIZE, id, "\n");
280 return len > PAGE_SIZE ? PAGE_SIZE : len;
284 online_show (struct device *dev, struct device_attribute *attr, char *buf)
286 struct ccw_device *cdev = to_ccwdev(dev);
288 return sprintf(buf, cdev->online ? "1\n" : "0\n");
291 int ccw_device_is_orphan(struct ccw_device *cdev)
293 return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
296 static void ccw_device_unregister(struct ccw_device *cdev)
298 if (device_is_registered(&cdev->dev)) {
299 /* Undo device_add(). */
300 device_del(&cdev->dev);
302 if (cdev->private->flags.initialized) {
303 cdev->private->flags.initialized = 0;
304 /* Release reference from device_initialize(). */
305 put_device(&cdev->dev);
309 static void io_subchannel_quiesce(struct subchannel *);
312 * ccw_device_set_offline() - disable a ccw device for I/O
313 * @cdev: target ccw device
315 * This function calls the driver's set_offline() function for @cdev, if
316 * given, and then disables @cdev.
318 * %0 on success and a negative error value on failure.
320 * enabled, ccw device lock not held
322 int ccw_device_set_offline(struct ccw_device *cdev)
324 struct subchannel *sch;
329 if (!cdev->online || !cdev->drv)
332 if (cdev->drv->set_offline) {
333 ret = cdev->drv->set_offline(cdev);
337 spin_lock_irq(cdev->ccwlock);
338 sch = to_subchannel(cdev->dev.parent);
340 /* Wait until a final state or DISCONNECTED is reached */
341 while (!dev_fsm_final_state(cdev) &&
342 cdev->private->state != DEV_STATE_DISCONNECTED) {
343 spin_unlock_irq(cdev->ccwlock);
344 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
345 cdev->private->state == DEV_STATE_DISCONNECTED));
346 spin_lock_irq(cdev->ccwlock);
349 ret = ccw_device_offline(cdev);
352 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
353 "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
354 cdev->private->dev_id.devno);
357 state = cdev->private->state;
358 spin_unlock_irq(cdev->ccwlock);
359 io_subchannel_quiesce(sch);
360 spin_lock_irq(cdev->ccwlock);
361 cdev->private->state = state;
362 } while (ret == -EBUSY);
363 spin_unlock_irq(cdev->ccwlock);
364 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
365 cdev->private->state == DEV_STATE_DISCONNECTED));
366 /* Inform the user if set offline failed. */
367 if (cdev->private->state == DEV_STATE_BOXED) {
368 pr_warn("%s: The device entered boxed state while being set offline\n",
369 dev_name(&cdev->dev));
370 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
371 pr_warn("%s: The device stopped operating while being set offline\n",
372 dev_name(&cdev->dev));
374 /* Give up reference from ccw_device_set_online(). */
375 put_device(&cdev->dev);
379 cdev->private->state = DEV_STATE_OFFLINE;
380 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
381 spin_unlock_irq(cdev->ccwlock);
382 /* Give up reference from ccw_device_set_online(). */
383 put_device(&cdev->dev);
388 * ccw_device_set_online() - enable a ccw device for I/O
389 * @cdev: target ccw device
391 * This function first enables @cdev and then calls the driver's set_online()
392 * function for @cdev, if given. If set_online() returns an error, @cdev is
395 * %0 on success and a negative error value on failure.
397 * enabled, ccw device lock not held
399 int ccw_device_set_online(struct ccw_device *cdev)
406 if (cdev->online || !cdev->drv)
408 /* Hold on to an extra reference while device is online. */
409 if (!get_device(&cdev->dev))
412 spin_lock_irq(cdev->ccwlock);
413 ret = ccw_device_online(cdev);
414 spin_unlock_irq(cdev->ccwlock);
416 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
418 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
419 "device 0.%x.%04x\n",
420 ret, cdev->private->dev_id.ssid,
421 cdev->private->dev_id.devno);
422 /* Give up online reference since onlining failed. */
423 put_device(&cdev->dev);
426 spin_lock_irq(cdev->ccwlock);
427 /* Check if online processing was successful */
428 if ((cdev->private->state != DEV_STATE_ONLINE) &&
429 (cdev->private->state != DEV_STATE_W4SENSE)) {
430 spin_unlock_irq(cdev->ccwlock);
431 /* Inform the user that set online failed. */
432 if (cdev->private->state == DEV_STATE_BOXED) {
433 pr_warn("%s: Setting the device online failed because it is boxed\n",
434 dev_name(&cdev->dev));
435 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
436 pr_warn("%s: Setting the device online failed because it is not operational\n",
437 dev_name(&cdev->dev));
439 /* Give up online reference since onlining failed. */
440 put_device(&cdev->dev);
443 spin_unlock_irq(cdev->ccwlock);
444 if (cdev->drv->set_online)
445 ret = cdev->drv->set_online(cdev);
449 spin_lock_irq(cdev->ccwlock);
451 spin_unlock_irq(cdev->ccwlock);
455 spin_lock_irq(cdev->ccwlock);
456 /* Wait until a final state or DISCONNECTED is reached */
457 while (!dev_fsm_final_state(cdev) &&
458 cdev->private->state != DEV_STATE_DISCONNECTED) {
459 spin_unlock_irq(cdev->ccwlock);
460 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
461 cdev->private->state == DEV_STATE_DISCONNECTED));
462 spin_lock_irq(cdev->ccwlock);
464 ret2 = ccw_device_offline(cdev);
467 spin_unlock_irq(cdev->ccwlock);
468 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
469 cdev->private->state == DEV_STATE_DISCONNECTED));
470 /* Give up online reference since onlining failed. */
471 put_device(&cdev->dev);
475 CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
476 "device 0.%x.%04x\n",
477 ret2, cdev->private->dev_id.ssid,
478 cdev->private->dev_id.devno);
479 cdev->private->state = DEV_STATE_OFFLINE;
480 spin_unlock_irq(cdev->ccwlock);
481 /* Give up online reference since onlining failed. */
482 put_device(&cdev->dev);
486 static int online_store_handle_offline(struct ccw_device *cdev)
488 if (cdev->private->state == DEV_STATE_DISCONNECTED) {
489 spin_lock_irq(cdev->ccwlock);
490 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
491 spin_unlock_irq(cdev->ccwlock);
494 if (cdev->drv && cdev->drv->set_offline)
495 return ccw_device_set_offline(cdev);
499 static int online_store_recog_and_online(struct ccw_device *cdev)
501 /* Do device recognition, if needed. */
502 if (cdev->private->state == DEV_STATE_BOXED) {
503 spin_lock_irq(cdev->ccwlock);
504 ccw_device_recognition(cdev);
505 spin_unlock_irq(cdev->ccwlock);
506 wait_event(cdev->private->wait_q,
507 cdev->private->flags.recog_done);
508 if (cdev->private->state != DEV_STATE_OFFLINE)
509 /* recognition failed */
512 if (cdev->drv && cdev->drv->set_online)
513 return ccw_device_set_online(cdev);
517 static int online_store_handle_online(struct ccw_device *cdev, int force)
521 ret = online_store_recog_and_online(cdev);
524 if (force && cdev->private->state == DEV_STATE_BOXED) {
525 ret = ccw_device_stlck(cdev);
528 if (cdev->id.cu_type == 0)
529 cdev->private->state = DEV_STATE_NOT_OPER;
530 ret = online_store_recog_and_online(cdev);
537 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
538 const char *buf, size_t count)
540 struct ccw_device *cdev = to_ccwdev(dev);
544 /* Prevent conflict between multiple on-/offline processing requests. */
545 if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
547 /* Prevent conflict between internal I/Os and on-/offline processing. */
548 if (!dev_fsm_final_state(cdev) &&
549 cdev->private->state != DEV_STATE_DISCONNECTED) {
553 /* Prevent conflict between pending work and on-/offline processing.*/
554 if (work_pending(&cdev->private->todo_work)) {
558 if (!strncmp(buf, "force\n", count)) {
564 ret = kstrtoul(buf, 16, &i);
572 ret = online_store_handle_offline(cdev);
575 ret = online_store_handle_online(cdev, force);
583 atomic_set(&cdev->private->onoff, 0);
584 return (ret < 0) ? ret : count;
588 available_show (struct device *dev, struct device_attribute *attr, char *buf)
590 struct ccw_device *cdev = to_ccwdev(dev);
591 struct subchannel *sch;
593 if (ccw_device_is_orphan(cdev))
594 return sprintf(buf, "no device\n");
595 switch (cdev->private->state) {
596 case DEV_STATE_BOXED:
597 return sprintf(buf, "boxed\n");
598 case DEV_STATE_DISCONNECTED:
599 case DEV_STATE_DISCONNECTED_SENSE_ID:
600 case DEV_STATE_NOT_OPER:
601 sch = to_subchannel(dev->parent);
603 return sprintf(buf, "no path\n");
605 return sprintf(buf, "no device\n");
607 /* All other states considered fine. */
608 return sprintf(buf, "good\n");
613 initiate_logging(struct device *dev, struct device_attribute *attr,
614 const char *buf, size_t count)
616 struct subchannel *sch = to_subchannel(dev);
619 rc = chsc_siosl(sch->schid);
621 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
622 sch->schid.ssid, sch->schid.sch_no, rc);
625 pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
626 sch->schid.ssid, sch->schid.sch_no);
630 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
633 struct subchannel *sch = to_subchannel(dev);
635 return sprintf(buf, "%02x\n", sch->vpm);
638 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
639 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
640 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
641 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
642 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
643 static DEVICE_ATTR(online, 0644, online_show, online_store);
644 static DEVICE_ATTR(availability, 0444, available_show, NULL);
645 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
646 static DEVICE_ATTR(vpm, 0444, vpm_show, NULL);
648 static struct attribute *io_subchannel_attrs[] = {
649 &dev_attr_chpids.attr,
650 &dev_attr_pimpampom.attr,
651 &dev_attr_logging.attr,
656 static struct attribute_group io_subchannel_attr_group = {
657 .attrs = io_subchannel_attrs,
660 static struct attribute * ccwdev_attrs[] = {
661 &dev_attr_devtype.attr,
662 &dev_attr_cutype.attr,
663 &dev_attr_modalias.attr,
664 &dev_attr_online.attr,
665 &dev_attr_cmb_enable.attr,
666 &dev_attr_availability.attr,
670 static struct attribute_group ccwdev_attr_group = {
671 .attrs = ccwdev_attrs,
674 static const struct attribute_group *ccwdev_attr_groups[] = {
679 static int ccw_device_add(struct ccw_device *cdev)
681 struct device *dev = &cdev->dev;
683 dev->bus = &ccw_bus_type;
684 return device_add(dev);
687 static int match_dev_id(struct device *dev, void *data)
689 struct ccw_device *cdev = to_ccwdev(dev);
690 struct ccw_dev_id *dev_id = data;
692 return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
696 * get_ccwdev_by_dev_id() - obtain device from a ccw device id
697 * @dev_id: id of the device to be searched
699 * This function searches all devices attached to the ccw bus for a device
702 * If a device is found its reference count is increased and returned;
703 * else %NULL is returned.
705 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
709 dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
711 return dev ? to_ccwdev(dev) : NULL;
713 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
715 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
719 if (device_is_registered(&cdev->dev)) {
720 device_release_driver(&cdev->dev);
721 ret = device_attach(&cdev->dev);
722 WARN_ON(ret == -ENODEV);
727 ccw_device_release(struct device *dev)
729 struct ccw_device *cdev;
731 cdev = to_ccwdev(dev);
732 /* Release reference of parent subchannel. */
733 put_device(cdev->dev.parent);
734 kfree(cdev->private);
738 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
740 struct ccw_device *cdev;
742 cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
744 cdev->private = kzalloc(sizeof(struct ccw_device_private),
745 GFP_KERNEL | GFP_DMA);
750 return ERR_PTR(-ENOMEM);
753 static void ccw_device_todo(struct work_struct *work);
755 static int io_subchannel_initialize_dev(struct subchannel *sch,
756 struct ccw_device *cdev)
758 struct ccw_device_private *priv = cdev->private;
762 priv->int_class = IRQIO_CIO;
763 priv->state = DEV_STATE_NOT_OPER;
764 priv->dev_id.devno = sch->schib.pmcw.dev;
765 priv->dev_id.ssid = sch->schid.ssid;
767 INIT_WORK(&priv->todo_work, ccw_device_todo);
768 INIT_LIST_HEAD(&priv->cmb_list);
769 init_waitqueue_head(&priv->wait_q);
770 init_timer(&priv->timer);
772 atomic_set(&priv->onoff, 0);
773 cdev->ccwlock = sch->lock;
774 cdev->dev.parent = &sch->dev;
775 cdev->dev.release = ccw_device_release;
776 cdev->dev.groups = ccwdev_attr_groups;
777 /* Do first half of device_register. */
778 device_initialize(&cdev->dev);
779 ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
780 cdev->private->dev_id.devno);
783 if (!get_device(&sch->dev)) {
787 priv->flags.initialized = 1;
788 spin_lock_irq(sch->lock);
789 sch_set_cdev(sch, cdev);
790 spin_unlock_irq(sch->lock);
794 /* Release reference from device_initialize(). */
795 put_device(&cdev->dev);
799 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
801 struct ccw_device *cdev;
804 cdev = io_subchannel_allocate_dev(sch);
806 ret = io_subchannel_initialize_dev(sch, cdev);
813 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
815 static void sch_create_and_recog_new_device(struct subchannel *sch)
817 struct ccw_device *cdev;
819 /* Need to allocate a new ccw device. */
820 cdev = io_subchannel_create_ccwdev(sch);
822 /* OK, we did everything we could... */
823 css_sch_device_unregister(sch);
826 /* Start recognition for the new ccw device. */
827 io_subchannel_recog(cdev, sch);
831 * Register recognized device.
833 static void io_subchannel_register(struct ccw_device *cdev)
835 struct subchannel *sch;
836 int ret, adjust_init_count = 1;
839 sch = to_subchannel(cdev->dev.parent);
841 * Check if subchannel is still registered. It may have become
842 * unregistered if a machine check hit us after finishing
843 * device recognition but before the register work could be
846 if (!device_is_registered(&sch->dev))
848 css_update_ssd_info(sch);
850 * io_subchannel_register() will also be called after device
851 * recognition has been done for a boxed device (which will already
852 * be registered). We need to reprobe since we may now have sense id
855 if (device_is_registered(&cdev->dev)) {
857 ret = device_reprobe(&cdev->dev);
859 /* We can't do much here. */
860 CIO_MSG_EVENT(0, "device_reprobe() returned"
861 " %d for 0.%x.%04x\n", ret,
862 cdev->private->dev_id.ssid,
863 cdev->private->dev_id.devno);
865 adjust_init_count = 0;
869 * Now we know this subchannel will stay, we can throw
870 * our delayed uevent.
872 dev_set_uevent_suppress(&sch->dev, 0);
873 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
874 /* make it known to the system */
875 ret = ccw_device_add(cdev);
877 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
878 cdev->private->dev_id.ssid,
879 cdev->private->dev_id.devno, ret);
880 spin_lock_irqsave(sch->lock, flags);
881 sch_set_cdev(sch, NULL);
882 spin_unlock_irqrestore(sch->lock, flags);
883 /* Release initial device reference. */
884 put_device(&cdev->dev);
888 cdev->private->flags.recog_done = 1;
889 wake_up(&cdev->private->wait_q);
891 if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
892 wake_up(&ccw_device_init_wq);
895 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
897 struct subchannel *sch;
899 /* Get subchannel reference for local processing. */
900 if (!get_device(cdev->dev.parent))
902 sch = to_subchannel(cdev->dev.parent);
903 css_sch_device_unregister(sch);
904 /* Release subchannel reference for local processing. */
905 put_device(&sch->dev);
909 * subchannel recognition done. Called from the state machine.
912 io_subchannel_recog_done(struct ccw_device *cdev)
914 if (css_init_done == 0) {
915 cdev->private->flags.recog_done = 1;
918 switch (cdev->private->state) {
919 case DEV_STATE_BOXED:
920 /* Device did not respond in time. */
921 case DEV_STATE_NOT_OPER:
922 cdev->private->flags.recog_done = 1;
923 /* Remove device found not operational. */
924 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
925 if (atomic_dec_and_test(&ccw_device_init_count))
926 wake_up(&ccw_device_init_wq);
928 case DEV_STATE_OFFLINE:
930 * We can't register the device in interrupt context so
931 * we schedule a work item.
933 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
938 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
940 /* Increase counter of devices currently in recognition. */
941 atomic_inc(&ccw_device_init_count);
943 /* Start async. device sensing. */
944 spin_lock_irq(sch->lock);
945 ccw_device_recognition(cdev);
946 spin_unlock_irq(sch->lock);
949 static int ccw_device_move_to_sch(struct ccw_device *cdev,
950 struct subchannel *sch)
952 struct subchannel *old_sch;
953 int rc, old_enabled = 0;
955 old_sch = to_subchannel(cdev->dev.parent);
956 /* Obtain child reference for new parent. */
957 if (!get_device(&sch->dev))
960 if (!sch_is_pseudo_sch(old_sch)) {
961 spin_lock_irq(old_sch->lock);
962 old_enabled = old_sch->schib.pmcw.ena;
965 rc = cio_disable_subchannel(old_sch);
966 spin_unlock_irq(old_sch->lock);
968 /* Release child reference for new parent. */
969 put_device(&sch->dev);
974 mutex_lock(&sch->reg_mutex);
975 rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
976 mutex_unlock(&sch->reg_mutex);
978 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
979 cdev->private->dev_id.ssid,
980 cdev->private->dev_id.devno, sch->schid.ssid,
981 sch->schib.pmcw.dev, rc);
983 /* Try to reenable the old subchannel. */
984 spin_lock_irq(old_sch->lock);
985 cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
986 spin_unlock_irq(old_sch->lock);
988 /* Release child reference for new parent. */
989 put_device(&sch->dev);
992 /* Clean up old subchannel. */
993 if (!sch_is_pseudo_sch(old_sch)) {
994 spin_lock_irq(old_sch->lock);
995 sch_set_cdev(old_sch, NULL);
996 spin_unlock_irq(old_sch->lock);
997 css_schedule_eval(old_sch->schid);
999 /* Release child reference for old parent. */
1000 put_device(&old_sch->dev);
1001 /* Initialize new subchannel. */
1002 spin_lock_irq(sch->lock);
1003 cdev->ccwlock = sch->lock;
1004 if (!sch_is_pseudo_sch(sch))
1005 sch_set_cdev(sch, cdev);
1006 spin_unlock_irq(sch->lock);
1007 if (!sch_is_pseudo_sch(sch))
1008 css_update_ssd_info(sch);
1012 static int ccw_device_move_to_orph(struct ccw_device *cdev)
1014 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1015 struct channel_subsystem *css = to_css(sch->dev.parent);
1017 return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
1020 static void io_subchannel_irq(struct subchannel *sch)
1022 struct ccw_device *cdev;
1024 cdev = sch_get_cdev(sch);
1026 CIO_TRACE_EVENT(6, "IRQ");
1027 CIO_TRACE_EVENT(6, dev_name(&sch->dev));
1029 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
1031 inc_irq_stat(IRQIO_CIO);
1034 void io_subchannel_init_config(struct subchannel *sch)
1036 memset(&sch->config, 0, sizeof(sch->config));
1037 sch->config.csense = 1;
1040 static void io_subchannel_init_fields(struct subchannel *sch)
1042 if (cio_is_console(sch->schid))
1045 sch->opm = chp_get_sch_opm(sch);
1046 sch->lpm = sch->schib.pmcw.pam & sch->opm;
1047 sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1049 CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1050 " - PIM = %02X, PAM = %02X, POM = %02X\n",
1051 sch->schib.pmcw.dev, sch->schid.ssid,
1052 sch->schid.sch_no, sch->schib.pmcw.pim,
1053 sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1055 io_subchannel_init_config(sch);
1059 * Note: We always return 0 so that we bind to the device even on error.
1060 * This is needed so that our remove function is called on unregister.
1062 static int io_subchannel_probe(struct subchannel *sch)
1064 struct io_subchannel_private *io_priv;
1065 struct ccw_device *cdev;
1068 if (cio_is_console(sch->schid)) {
1069 rc = sysfs_create_group(&sch->dev.kobj,
1070 &io_subchannel_attr_group);
1072 CIO_MSG_EVENT(0, "Failed to create io subchannel "
1073 "attributes for subchannel "
1074 "0.%x.%04x (rc=%d)\n",
1075 sch->schid.ssid, sch->schid.sch_no, rc);
1077 * The console subchannel already has an associated ccw_device.
1078 * Throw the delayed uevent for the subchannel, register
1079 * the ccw_device and exit.
1081 dev_set_uevent_suppress(&sch->dev, 0);
1082 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1083 cdev = sch_get_cdev(sch);
1084 rc = ccw_device_add(cdev);
1086 /* Release online reference. */
1087 put_device(&cdev->dev);
1090 if (atomic_dec_and_test(&ccw_device_init_count))
1091 wake_up(&ccw_device_init_wq);
1094 io_subchannel_init_fields(sch);
1095 rc = cio_commit_config(sch);
1098 rc = sysfs_create_group(&sch->dev.kobj,
1099 &io_subchannel_attr_group);
1102 /* Allocate I/O subchannel private data. */
1103 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1107 set_io_private(sch, io_priv);
1108 css_schedule_eval(sch->schid);
1112 spin_lock_irq(sch->lock);
1113 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1114 spin_unlock_irq(sch->lock);
1119 io_subchannel_remove (struct subchannel *sch)
1121 struct io_subchannel_private *io_priv = to_io_private(sch);
1122 struct ccw_device *cdev;
1124 cdev = sch_get_cdev(sch);
1127 io_subchannel_quiesce(sch);
1128 /* Set ccw device to not operational and drop reference. */
1129 spin_lock_irq(cdev->ccwlock);
1130 sch_set_cdev(sch, NULL);
1131 set_io_private(sch, NULL);
1132 cdev->private->state = DEV_STATE_NOT_OPER;
1133 spin_unlock_irq(cdev->ccwlock);
1134 ccw_device_unregister(cdev);
1137 sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1141 static void io_subchannel_verify(struct subchannel *sch)
1143 struct ccw_device *cdev;
1145 cdev = sch_get_cdev(sch);
1147 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1150 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1152 struct ccw_device *cdev;
1154 cdev = sch_get_cdev(sch);
1157 if (cio_update_schib(sch))
1159 /* Check for I/O on path. */
1160 if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1162 if (cdev->private->state == DEV_STATE_ONLINE) {
1163 ccw_device_kill_io(cdev);
1169 /* Trigger path verification. */
1170 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1174 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1177 static int io_subchannel_chp_event(struct subchannel *sch,
1178 struct chp_link *link, int event)
1180 struct ccw_device *cdev = sch_get_cdev(sch);
1183 mask = chp_ssd_get_mask(&sch->ssd_info, link);
1191 cdev->private->path_gone_mask |= mask;
1192 io_subchannel_terminate_path(sch, mask);
1198 cdev->private->path_new_mask |= mask;
1199 io_subchannel_verify(sch);
1202 if (cio_update_schib(sch))
1205 cdev->private->path_gone_mask |= mask;
1206 io_subchannel_terminate_path(sch, mask);
1209 if (cio_update_schib(sch))
1211 sch->lpm |= mask & sch->opm;
1213 cdev->private->path_new_mask |= mask;
1214 io_subchannel_verify(sch);
1220 static void io_subchannel_quiesce(struct subchannel *sch)
1222 struct ccw_device *cdev;
1225 spin_lock_irq(sch->lock);
1226 cdev = sch_get_cdev(sch);
1227 if (cio_is_console(sch->schid))
1229 if (!sch->schib.pmcw.ena)
1231 ret = cio_disable_subchannel(sch);
1235 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1236 while (ret == -EBUSY) {
1237 cdev->private->state = DEV_STATE_QUIESCE;
1238 cdev->private->iretry = 255;
1239 ret = ccw_device_cancel_halt_clear(cdev);
1240 if (ret == -EBUSY) {
1241 ccw_device_set_timeout(cdev, HZ/10);
1242 spin_unlock_irq(sch->lock);
1243 wait_event(cdev->private->wait_q,
1244 cdev->private->state != DEV_STATE_QUIESCE);
1245 spin_lock_irq(sch->lock);
1247 ret = cio_disable_subchannel(sch);
1250 spin_unlock_irq(sch->lock);
1253 static void io_subchannel_shutdown(struct subchannel *sch)
1255 io_subchannel_quiesce(sch);
1258 static int device_is_disconnected(struct ccw_device *cdev)
1262 return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1263 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1266 static int recovery_check(struct device *dev, void *data)
1268 struct ccw_device *cdev = to_ccwdev(dev);
1271 spin_lock_irq(cdev->ccwlock);
1272 switch (cdev->private->state) {
1273 case DEV_STATE_DISCONNECTED:
1274 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1275 cdev->private->dev_id.ssid,
1276 cdev->private->dev_id.devno);
1277 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1280 case DEV_STATE_DISCONNECTED_SENSE_ID:
1284 spin_unlock_irq(cdev->ccwlock);
1289 static void recovery_work_func(struct work_struct *unused)
1293 bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1295 spin_lock_irq(&recovery_lock);
1296 if (!timer_pending(&recovery_timer)) {
1297 if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1299 mod_timer(&recovery_timer, jiffies +
1300 recovery_delay[recovery_phase] * HZ);
1302 spin_unlock_irq(&recovery_lock);
1304 CIO_MSG_EVENT(4, "recovery: end\n");
1307 static DECLARE_WORK(recovery_work, recovery_work_func);
1309 static void recovery_func(unsigned long data)
1312 * We can't do our recovery in softirq context and it's not
1313 * performance critical, so we schedule it.
1315 schedule_work(&recovery_work);
1318 static void ccw_device_schedule_recovery(void)
1320 unsigned long flags;
1322 CIO_MSG_EVENT(4, "recovery: schedule\n");
1323 spin_lock_irqsave(&recovery_lock, flags);
1324 if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1326 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1328 spin_unlock_irqrestore(&recovery_lock, flags);
1331 static int purge_fn(struct device *dev, void *data)
1333 struct ccw_device *cdev = to_ccwdev(dev);
1334 struct ccw_dev_id *id = &cdev->private->dev_id;
1336 spin_lock_irq(cdev->ccwlock);
1337 if (is_blacklisted(id->ssid, id->devno) &&
1338 (cdev->private->state == DEV_STATE_OFFLINE) &&
1339 (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1340 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1342 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1343 atomic_set(&cdev->private->onoff, 0);
1345 spin_unlock_irq(cdev->ccwlock);
1346 /* Abort loop in case of pending signal. */
1347 if (signal_pending(current))
1354 * ccw_purge_blacklisted - purge unused, blacklisted devices
1356 * Unregister all ccw devices that are offline and on the blacklist.
1358 int ccw_purge_blacklisted(void)
1360 CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1361 bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1365 void ccw_device_set_disconnected(struct ccw_device *cdev)
1369 ccw_device_set_timeout(cdev, 0);
1370 cdev->private->flags.fake_irb = 0;
1371 cdev->private->state = DEV_STATE_DISCONNECTED;
1373 ccw_device_schedule_recovery();
1376 void ccw_device_set_notoper(struct ccw_device *cdev)
1378 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1380 CIO_TRACE_EVENT(2, "notoper");
1381 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1382 ccw_device_set_timeout(cdev, 0);
1383 cio_disable_subchannel(sch);
1384 cdev->private->state = DEV_STATE_NOT_OPER;
1387 enum io_sch_action {
1391 IO_SCH_UNREG_ATTACH,
1399 static enum io_sch_action sch_get_action(struct subchannel *sch)
1401 struct ccw_device *cdev;
1403 cdev = sch_get_cdev(sch);
1404 if (cio_update_schib(sch)) {
1405 /* Not operational. */
1407 return IO_SCH_UNREG;
1408 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1409 return IO_SCH_UNREG;
1410 return IO_SCH_ORPH_UNREG;
1414 return IO_SCH_ATTACH;
1415 if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1416 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1417 return IO_SCH_UNREG_ATTACH;
1418 return IO_SCH_ORPH_ATTACH;
1420 if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1421 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1422 return IO_SCH_UNREG;
1425 if (device_is_disconnected(cdev))
1426 return IO_SCH_REPROBE;
1427 if (cdev->online && !cdev->private->flags.resuming)
1428 return IO_SCH_VERIFY;
1429 if (cdev->private->state == DEV_STATE_NOT_OPER)
1430 return IO_SCH_UNREG_ATTACH;
1435 * io_subchannel_sch_event - process subchannel event
1437 * @process: non-zero if function is called in process context
1439 * An unspecified event occurred for this subchannel. Adjust data according
1440 * to the current operational state of the subchannel and device. Return
1441 * zero when the event has been handled sufficiently or -EAGAIN when this
1442 * function should be called again in process context.
1444 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1446 unsigned long flags;
1447 struct ccw_device *cdev;
1448 struct ccw_dev_id dev_id;
1449 enum io_sch_action action;
1452 spin_lock_irqsave(sch->lock, flags);
1453 if (!device_is_registered(&sch->dev))
1455 if (work_pending(&sch->todo_work))
1457 cdev = sch_get_cdev(sch);
1458 if (cdev && work_pending(&cdev->private->todo_work))
1460 action = sch_get_action(sch);
1461 CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1462 sch->schid.ssid, sch->schid.sch_no, process,
1464 /* Perform immediate actions while holding the lock. */
1466 case IO_SCH_REPROBE:
1467 /* Trigger device recognition. */
1468 ccw_device_trigger_reprobe(cdev);
1472 /* Trigger path verification. */
1473 io_subchannel_verify(sch);
1477 ccw_device_set_disconnected(cdev);
1480 case IO_SCH_ORPH_UNREG:
1481 case IO_SCH_ORPH_ATTACH:
1482 ccw_device_set_disconnected(cdev);
1484 case IO_SCH_UNREG_ATTACH:
1488 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1490 * Note: delayed work triggered by this event
1491 * and repeated calls to sch_event are synchronized
1492 * by the above check for work_pending(cdev).
1494 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1496 ccw_device_set_notoper(cdev);
1504 spin_unlock_irqrestore(sch->lock, flags);
1505 /* All other actions require process context. */
1508 /* Handle attached ccw device. */
1510 case IO_SCH_ORPH_UNREG:
1511 case IO_SCH_ORPH_ATTACH:
1512 /* Move ccw device to orphanage. */
1513 rc = ccw_device_move_to_orph(cdev);
1517 case IO_SCH_UNREG_ATTACH:
1518 spin_lock_irqsave(sch->lock, flags);
1519 if (cdev->private->flags.resuming) {
1520 /* Device will be handled later. */
1524 sch_set_cdev(sch, NULL);
1525 spin_unlock_irqrestore(sch->lock, flags);
1526 /* Unregister ccw device. */
1527 ccw_device_unregister(cdev);
1532 /* Handle subchannel. */
1534 case IO_SCH_ORPH_UNREG:
1536 if (!cdev || !cdev->private->flags.resuming)
1537 css_sch_device_unregister(sch);
1539 case IO_SCH_ORPH_ATTACH:
1540 case IO_SCH_UNREG_ATTACH:
1542 dev_id.ssid = sch->schid.ssid;
1543 dev_id.devno = sch->schib.pmcw.dev;
1544 cdev = get_ccwdev_by_dev_id(&dev_id);
1546 sch_create_and_recog_new_device(sch);
1549 rc = ccw_device_move_to_sch(cdev, sch);
1551 /* Release reference from get_ccwdev_by_dev_id() */
1552 put_device(&cdev->dev);
1555 spin_lock_irqsave(sch->lock, flags);
1556 ccw_device_trigger_reprobe(cdev);
1557 spin_unlock_irqrestore(sch->lock, flags);
1558 /* Release reference from get_ccwdev_by_dev_id() */
1559 put_device(&cdev->dev);
1567 spin_unlock_irqrestore(sch->lock, flags);
1572 static void ccw_device_set_int_class(struct ccw_device *cdev)
1574 struct ccw_driver *cdrv = cdev->drv;
1576 /* Note: we interpret class 0 in this context as an uninitialized
1577 * field since it translates to a non-I/O interrupt class. */
1578 if (cdrv->int_class != 0)
1579 cdev->private->int_class = cdrv->int_class;
1581 cdev->private->int_class = IRQIO_CIO;
1584 #ifdef CONFIG_CCW_CONSOLE
1585 int __init ccw_device_enable_console(struct ccw_device *cdev)
1587 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1590 if (!cdev->drv || !cdev->handler)
1593 io_subchannel_init_fields(sch);
1594 rc = cio_commit_config(sch);
1597 sch->driver = &io_subchannel_driver;
1598 io_subchannel_recog(cdev, sch);
1599 /* Now wait for the async. recognition to come to an end. */
1600 spin_lock_irq(cdev->ccwlock);
1601 while (!dev_fsm_final_state(cdev))
1602 ccw_device_wait_idle(cdev);
1604 /* Hold on to an extra reference while device is online. */
1605 get_device(&cdev->dev);
1606 rc = ccw_device_online(cdev);
1610 while (!dev_fsm_final_state(cdev))
1611 ccw_device_wait_idle(cdev);
1613 if (cdev->private->state == DEV_STATE_ONLINE)
1618 spin_unlock_irq(cdev->ccwlock);
1619 if (rc) /* Give up online reference since onlining failed. */
1620 put_device(&cdev->dev);
1624 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1626 struct io_subchannel_private *io_priv;
1627 struct ccw_device *cdev;
1628 struct subchannel *sch;
1630 sch = cio_probe_console();
1632 return ERR_CAST(sch);
1634 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1636 put_device(&sch->dev);
1637 return ERR_PTR(-ENOMEM);
1639 set_io_private(sch, io_priv);
1640 cdev = io_subchannel_create_ccwdev(sch);
1642 put_device(&sch->dev);
1647 ccw_device_set_int_class(cdev);
1651 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1653 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1654 struct io_subchannel_private *io_priv = to_io_private(sch);
1656 set_io_private(sch, NULL);
1657 put_device(&sch->dev);
1658 put_device(&cdev->dev);
1663 * ccw_device_wait_idle() - busy wait for device to become idle
1666 * Poll until activity control is zero, that is, no function or data
1667 * transfer is pending/active.
1668 * Called with device lock being held.
1670 void ccw_device_wait_idle(struct ccw_device *cdev)
1672 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1676 if (sch->schib.scsw.cmd.actl == 0)
1682 static int ccw_device_pm_restore(struct device *dev);
1684 int ccw_device_force_console(struct ccw_device *cdev)
1686 return ccw_device_pm_restore(&cdev->dev);
1688 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1692 * get ccw_device matching the busid, but only if owned by cdrv
1695 __ccwdev_check_busid(struct device *dev, void *id)
1701 return (strcmp(bus_id, dev_name(dev)) == 0);
1706 * get_ccwdev_by_busid() - obtain device from a bus id
1707 * @cdrv: driver the device is owned by
1708 * @bus_id: bus id of the device to be searched
1710 * This function searches all devices owned by @cdrv for a device with a bus
1711 * id matching @bus_id.
1713 * If a match is found, its reference count of the found device is increased
1714 * and it is returned; else %NULL is returned.
1716 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1721 dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1722 __ccwdev_check_busid);
1724 return dev ? to_ccwdev(dev) : NULL;
1727 /************************** device driver handling ************************/
1729 /* This is the implementation of the ccw_driver class. The probe, remove
1730 * and release methods are initially very similar to the device_driver
1731 * implementations, with the difference that they have ccw_device
1734 * A ccw driver also contains the information that is needed for
1738 ccw_device_probe (struct device *dev)
1740 struct ccw_device *cdev = to_ccwdev(dev);
1741 struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1744 cdev->drv = cdrv; /* to let the driver call _set_online */
1745 ccw_device_set_int_class(cdev);
1746 ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1749 cdev->private->int_class = IRQIO_CIO;
1756 static int ccw_device_remove(struct device *dev)
1758 struct ccw_device *cdev = to_ccwdev(dev);
1759 struct ccw_driver *cdrv = cdev->drv;
1765 spin_lock_irq(cdev->ccwlock);
1768 ret = ccw_device_offline(cdev);
1769 spin_unlock_irq(cdev->ccwlock);
1771 wait_event(cdev->private->wait_q,
1772 dev_fsm_final_state(cdev));
1774 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1775 "device 0.%x.%04x\n",
1776 ret, cdev->private->dev_id.ssid,
1777 cdev->private->dev_id.devno);
1778 /* Give up reference obtained in ccw_device_set_online(). */
1779 put_device(&cdev->dev);
1780 spin_lock_irq(cdev->ccwlock);
1782 ccw_device_set_timeout(cdev, 0);
1784 cdev->private->int_class = IRQIO_CIO;
1785 spin_unlock_irq(cdev->ccwlock);
1786 __disable_cmf(cdev);
1791 static void ccw_device_shutdown(struct device *dev)
1793 struct ccw_device *cdev;
1795 cdev = to_ccwdev(dev);
1796 if (cdev->drv && cdev->drv->shutdown)
1797 cdev->drv->shutdown(cdev);
1798 __disable_cmf(cdev);
1801 static int ccw_device_pm_prepare(struct device *dev)
1803 struct ccw_device *cdev = to_ccwdev(dev);
1805 if (work_pending(&cdev->private->todo_work))
1807 /* Fail while device is being set online/offline. */
1808 if (atomic_read(&cdev->private->onoff))
1811 if (cdev->online && cdev->drv && cdev->drv->prepare)
1812 return cdev->drv->prepare(cdev);
1817 static void ccw_device_pm_complete(struct device *dev)
1819 struct ccw_device *cdev = to_ccwdev(dev);
1821 if (cdev->online && cdev->drv && cdev->drv->complete)
1822 cdev->drv->complete(cdev);
1825 static int ccw_device_pm_freeze(struct device *dev)
1827 struct ccw_device *cdev = to_ccwdev(dev);
1828 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1829 int ret, cm_enabled;
1831 /* Fail suspend while device is in transistional state. */
1832 if (!dev_fsm_final_state(cdev))
1836 if (cdev->drv && cdev->drv->freeze) {
1837 ret = cdev->drv->freeze(cdev);
1842 spin_lock_irq(sch->lock);
1843 cm_enabled = cdev->private->cmb != NULL;
1844 spin_unlock_irq(sch->lock);
1846 /* Don't have the css write on memory. */
1847 ret = ccw_set_cmf(cdev, 0);
1851 /* From here on, disallow device driver I/O. */
1852 spin_lock_irq(sch->lock);
1853 ret = cio_disable_subchannel(sch);
1854 spin_unlock_irq(sch->lock);
1859 static int ccw_device_pm_thaw(struct device *dev)
1861 struct ccw_device *cdev = to_ccwdev(dev);
1862 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1863 int ret, cm_enabled;
1868 spin_lock_irq(sch->lock);
1869 /* Allow device driver I/O again. */
1870 ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1871 cm_enabled = cdev->private->cmb != NULL;
1872 spin_unlock_irq(sch->lock);
1877 ret = ccw_set_cmf(cdev, 1);
1882 if (cdev->drv && cdev->drv->thaw)
1883 ret = cdev->drv->thaw(cdev);
1888 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1890 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1892 spin_lock_irq(sch->lock);
1893 if (cio_is_console(sch->schid)) {
1894 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1898 * While we were sleeping, devices may have gone or become
1899 * available again. Kick re-detection.
1901 cdev->private->flags.resuming = 1;
1902 cdev->private->path_new_mask = LPM_ANYPATH;
1903 css_sched_sch_todo(sch, SCH_TODO_EVAL);
1904 spin_unlock_irq(sch->lock);
1905 css_wait_for_slow_path();
1907 /* cdev may have been moved to a different subchannel. */
1908 sch = to_subchannel(cdev->dev.parent);
1909 spin_lock_irq(sch->lock);
1910 if (cdev->private->state != DEV_STATE_ONLINE &&
1911 cdev->private->state != DEV_STATE_OFFLINE)
1914 ccw_device_recognition(cdev);
1915 spin_unlock_irq(sch->lock);
1916 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1917 cdev->private->state == DEV_STATE_DISCONNECTED);
1918 spin_lock_irq(sch->lock);
1921 cdev->private->flags.resuming = 0;
1922 spin_unlock_irq(sch->lock);
1925 static int resume_handle_boxed(struct ccw_device *cdev)
1927 cdev->private->state = DEV_STATE_BOXED;
1928 if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1930 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1934 static int resume_handle_disc(struct ccw_device *cdev)
1936 cdev->private->state = DEV_STATE_DISCONNECTED;
1937 if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1939 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1943 static int ccw_device_pm_restore(struct device *dev)
1945 struct ccw_device *cdev = to_ccwdev(dev);
1946 struct subchannel *sch;
1949 __ccw_device_pm_restore(cdev);
1950 sch = to_subchannel(cdev->dev.parent);
1951 spin_lock_irq(sch->lock);
1952 if (cio_is_console(sch->schid))
1955 /* check recognition results */
1956 switch (cdev->private->state) {
1957 case DEV_STATE_OFFLINE:
1958 case DEV_STATE_ONLINE:
1959 cdev->private->flags.donotify = 0;
1961 case DEV_STATE_BOXED:
1962 ret = resume_handle_boxed(cdev);
1967 ret = resume_handle_disc(cdev);
1972 /* check if the device type has changed */
1973 if (!ccw_device_test_sense_data(cdev)) {
1974 ccw_device_update_sense_data(cdev);
1975 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1982 if (ccw_device_online(cdev)) {
1983 ret = resume_handle_disc(cdev);
1988 spin_unlock_irq(sch->lock);
1989 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1990 spin_lock_irq(sch->lock);
1992 if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1993 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1998 /* reenable cmf, if needed */
1999 if (cdev->private->cmb) {
2000 spin_unlock_irq(sch->lock);
2001 ret = ccw_set_cmf(cdev, 1);
2002 spin_lock_irq(sch->lock);
2004 CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
2005 "(rc=%d)\n", cdev->private->dev_id.ssid,
2006 cdev->private->dev_id.devno, ret);
2012 spin_unlock_irq(sch->lock);
2013 if (cdev->online && cdev->drv && cdev->drv->restore)
2014 ret = cdev->drv->restore(cdev);
2018 spin_unlock_irq(sch->lock);
2022 static const struct dev_pm_ops ccw_pm_ops = {
2023 .prepare = ccw_device_pm_prepare,
2024 .complete = ccw_device_pm_complete,
2025 .freeze = ccw_device_pm_freeze,
2026 .thaw = ccw_device_pm_thaw,
2027 .restore = ccw_device_pm_restore,
2030 static struct bus_type ccw_bus_type = {
2032 .match = ccw_bus_match,
2033 .uevent = ccw_uevent,
2034 .probe = ccw_device_probe,
2035 .remove = ccw_device_remove,
2036 .shutdown = ccw_device_shutdown,
2041 * ccw_driver_register() - register a ccw driver
2042 * @cdriver: driver to be registered
2044 * This function is mainly a wrapper around driver_register().
2046 * %0 on success and a negative error value on failure.
2048 int ccw_driver_register(struct ccw_driver *cdriver)
2050 struct device_driver *drv = &cdriver->driver;
2052 drv->bus = &ccw_bus_type;
2054 return driver_register(drv);
2058 * ccw_driver_unregister() - deregister a ccw driver
2059 * @cdriver: driver to be deregistered
2061 * This function is mainly a wrapper around driver_unregister().
2063 void ccw_driver_unregister(struct ccw_driver *cdriver)
2065 driver_unregister(&cdriver->driver);
2068 static void ccw_device_todo(struct work_struct *work)
2070 struct ccw_device_private *priv;
2071 struct ccw_device *cdev;
2072 struct subchannel *sch;
2073 enum cdev_todo todo;
2075 priv = container_of(work, struct ccw_device_private, todo_work);
2077 sch = to_subchannel(cdev->dev.parent);
2078 /* Find out todo. */
2079 spin_lock_irq(cdev->ccwlock);
2081 priv->todo = CDEV_TODO_NOTHING;
2082 CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2083 priv->dev_id.ssid, priv->dev_id.devno, todo);
2084 spin_unlock_irq(cdev->ccwlock);
2087 case CDEV_TODO_ENABLE_CMF:
2090 case CDEV_TODO_REBIND:
2091 ccw_device_do_unbind_bind(cdev);
2093 case CDEV_TODO_REGISTER:
2094 io_subchannel_register(cdev);
2096 case CDEV_TODO_UNREG_EVAL:
2097 if (!sch_is_pseudo_sch(sch))
2098 css_schedule_eval(sch->schid);
2100 case CDEV_TODO_UNREG:
2101 if (sch_is_pseudo_sch(sch))
2102 ccw_device_unregister(cdev);
2104 ccw_device_call_sch_unregister(cdev);
2109 /* Release workqueue ref. */
2110 put_device(&cdev->dev);
2114 * ccw_device_sched_todo - schedule ccw device operation
2118 * Schedule the operation identified by @todo to be performed on the slow path
2119 * workqueue. Do nothing if another operation with higher priority is already
2120 * scheduled. Needs to be called with ccwdev lock held.
2122 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2124 CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2125 cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2127 if (cdev->private->todo >= todo)
2129 cdev->private->todo = todo;
2130 /* Get workqueue ref. */
2131 if (!get_device(&cdev->dev))
2133 if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2134 /* Already queued, release workqueue ref. */
2135 put_device(&cdev->dev);
2140 * ccw_device_siosl() - initiate logging
2143 * This function is used to invoke model-dependent logging within the channel
2146 int ccw_device_siosl(struct ccw_device *cdev)
2148 struct subchannel *sch = to_subchannel(cdev->dev.parent);
2150 return chsc_siosl(sch->schid);
2152 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2154 EXPORT_SYMBOL(ccw_device_set_online);
2155 EXPORT_SYMBOL(ccw_device_set_offline);
2156 EXPORT_SYMBOL(ccw_driver_register);
2157 EXPORT_SYMBOL(ccw_driver_unregister);
2158 EXPORT_SYMBOL(get_ccwdev_by_busid);