1 // SPDX-License-Identifier: GPL-1.0+
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)
11 #define KMSG_COMPONENT "cio"
12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
14 #include <linux/export.h>
15 #include <linux/init.h>
16 #include <linux/spinlock.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 #include <linux/list.h>
21 #include <linux/device.h>
22 #include <linux/workqueue.h>
23 #include <linux/delay.h>
24 #include <linux/timer.h>
25 #include <linux/kernel_stat.h>
26 #include <linux/sched/signal.h>
27 #include <linux/dma-mapping.h>
29 #include <asm/ccwdev.h>
31 #include <asm/param.h> /* HZ */
37 #include "cio_debug.h"
42 #include "blacklist.h"
45 static struct timer_list recovery_timer;
46 static DEFINE_SPINLOCK(recovery_lock);
47 static int recovery_phase;
48 static const unsigned long recovery_delay[] = { 3, 30, 300 };
50 static atomic_t ccw_device_init_count = ATOMIC_INIT(0);
51 static DECLARE_WAIT_QUEUE_HEAD(ccw_device_init_wq);
52 static struct bus_type ccw_bus_type;
54 /******************* bus type handling ***********************/
56 /* The Linux driver model distinguishes between a bus type and
57 * the bus itself. Of course we only have one channel
58 * subsystem driver and one channel system per machine, but
59 * we still use the abstraction. T.R. says it's a good idea. */
61 ccw_bus_match (struct device * dev, struct device_driver * drv)
63 struct ccw_device *cdev = to_ccwdev(dev);
64 struct ccw_driver *cdrv = to_ccwdrv(drv);
65 const struct ccw_device_id *ids = cdrv->ids, *found;
70 found = ccw_device_id_match(ids, &cdev->id);
74 cdev->id.driver_info = found->driver_info;
79 /* Store modalias string delimited by prefix/suffix string into buffer with
80 * specified size. Return length of resulting string (excluding trailing '\0')
81 * even if string doesn't fit buffer (snprintf semantics). */
82 static int snprint_alias(char *buf, size_t size,
83 const struct ccw_device_id *id, const char *suffix)
87 len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
93 if (id->dev_type != 0)
94 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
95 id->dev_model, suffix);
97 len += snprintf(buf, size, "dtdm%s", suffix);
102 /* Set up environment variables for ccw device uevent. Return 0 on success,
103 * non-zero otherwise. */
104 static int ccw_uevent(const struct device *dev, struct kobj_uevent_env *env)
106 const struct ccw_device *cdev = to_ccwdev(dev);
107 const struct ccw_device_id *id = &(cdev->id);
109 char modalias_buf[30];
112 ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
117 ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
121 /* The next two can be zero, that's ok for us */
123 ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
128 ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
133 snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
134 ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
138 static void io_subchannel_irq(struct subchannel *);
139 static int io_subchannel_probe(struct subchannel *);
140 static void io_subchannel_remove(struct subchannel *);
141 static void io_subchannel_shutdown(struct subchannel *);
142 static int io_subchannel_sch_event(struct subchannel *, int);
143 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
145 static void recovery_func(struct timer_list *unused);
147 static struct css_device_id io_subchannel_ids[] = {
148 { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
149 { /* end of list */ },
152 static int io_subchannel_settle(void)
156 ret = wait_event_interruptible(ccw_device_init_wq,
157 atomic_read(&ccw_device_init_count) == 0);
160 flush_workqueue(cio_work_q);
164 static struct css_driver io_subchannel_driver = {
166 .owner = THIS_MODULE,
167 .name = "io_subchannel",
169 .subchannel_type = io_subchannel_ids,
170 .irq = io_subchannel_irq,
171 .sch_event = io_subchannel_sch_event,
172 .chp_event = io_subchannel_chp_event,
173 .probe = io_subchannel_probe,
174 .remove = io_subchannel_remove,
175 .shutdown = io_subchannel_shutdown,
176 .settle = io_subchannel_settle,
179 int __init io_subchannel_init(void)
183 timer_setup(&recovery_timer, recovery_func, 0);
184 ret = bus_register(&ccw_bus_type);
187 ret = css_driver_register(&io_subchannel_driver);
189 bus_unregister(&ccw_bus_type);
195 /************************ device handling **************************/
198 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
200 struct ccw_device *cdev = to_ccwdev(dev);
201 struct ccw_device_id *id = &(cdev->id);
203 if (id->dev_type != 0)
204 return sprintf(buf, "%04x/%02x\n",
205 id->dev_type, id->dev_model);
207 return sprintf(buf, "n/a\n");
211 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
213 struct ccw_device *cdev = to_ccwdev(dev);
214 struct ccw_device_id *id = &(cdev->id);
216 return sprintf(buf, "%04x/%02x\n",
217 id->cu_type, id->cu_model);
221 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
223 struct ccw_device *cdev = to_ccwdev(dev);
224 struct ccw_device_id *id = &(cdev->id);
227 len = snprint_alias(buf, PAGE_SIZE, id, "\n");
229 return len > PAGE_SIZE ? PAGE_SIZE : len;
233 online_show (struct device *dev, struct device_attribute *attr, char *buf)
235 struct ccw_device *cdev = to_ccwdev(dev);
237 return sprintf(buf, cdev->online ? "1\n" : "0\n");
240 int ccw_device_is_orphan(struct ccw_device *cdev)
242 return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
245 static void ccw_device_unregister(struct ccw_device *cdev)
247 mutex_lock(&cdev->reg_mutex);
248 if (device_is_registered(&cdev->dev)) {
249 /* Undo device_add(). */
250 device_del(&cdev->dev);
252 mutex_unlock(&cdev->reg_mutex);
254 if (cdev->private->flags.initialized) {
255 cdev->private->flags.initialized = 0;
256 /* Release reference from device_initialize(). */
257 put_device(&cdev->dev);
261 static void io_subchannel_quiesce(struct subchannel *);
264 * ccw_device_set_offline() - disable a ccw device for I/O
265 * @cdev: target ccw device
267 * This function calls the driver's set_offline() function for @cdev, if
268 * given, and then disables @cdev.
270 * %0 on success and a negative error value on failure.
272 * enabled, ccw device lock not held
274 int ccw_device_set_offline(struct ccw_device *cdev)
276 struct subchannel *sch;
281 if (!cdev->online || !cdev->drv)
284 if (cdev->drv->set_offline) {
285 ret = cdev->drv->set_offline(cdev);
289 spin_lock_irq(cdev->ccwlock);
290 sch = to_subchannel(cdev->dev.parent);
292 /* Wait until a final state or DISCONNECTED is reached */
293 while (!dev_fsm_final_state(cdev) &&
294 cdev->private->state != DEV_STATE_DISCONNECTED) {
295 spin_unlock_irq(cdev->ccwlock);
296 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
297 cdev->private->state == DEV_STATE_DISCONNECTED));
298 spin_lock_irq(cdev->ccwlock);
301 ret = ccw_device_offline(cdev);
304 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
305 "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
306 cdev->private->dev_id.devno);
309 state = cdev->private->state;
310 spin_unlock_irq(cdev->ccwlock);
311 io_subchannel_quiesce(sch);
312 spin_lock_irq(cdev->ccwlock);
313 cdev->private->state = state;
314 } while (ret == -EBUSY);
315 spin_unlock_irq(cdev->ccwlock);
316 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
317 cdev->private->state == DEV_STATE_DISCONNECTED));
318 /* Inform the user if set offline failed. */
319 if (cdev->private->state == DEV_STATE_BOXED) {
320 pr_warn("%s: The device entered boxed state while being set offline\n",
321 dev_name(&cdev->dev));
322 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
323 pr_warn("%s: The device stopped operating while being set offline\n",
324 dev_name(&cdev->dev));
326 /* Give up reference from ccw_device_set_online(). */
327 put_device(&cdev->dev);
331 cdev->private->state = DEV_STATE_OFFLINE;
332 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
333 spin_unlock_irq(cdev->ccwlock);
334 /* Give up reference from ccw_device_set_online(). */
335 put_device(&cdev->dev);
340 * ccw_device_set_online() - enable a ccw device for I/O
341 * @cdev: target ccw device
343 * This function first enables @cdev and then calls the driver's set_online()
344 * function for @cdev, if given. If set_online() returns an error, @cdev is
347 * %0 on success and a negative error value on failure.
349 * enabled, ccw device lock not held
351 int ccw_device_set_online(struct ccw_device *cdev)
358 if (cdev->online || !cdev->drv)
360 /* Hold on to an extra reference while device is online. */
361 if (!get_device(&cdev->dev))
364 spin_lock_irq(cdev->ccwlock);
365 ret = ccw_device_online(cdev);
367 spin_unlock_irq(cdev->ccwlock);
368 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
369 "device 0.%x.%04x\n",
370 ret, cdev->private->dev_id.ssid,
371 cdev->private->dev_id.devno);
372 /* Give up online reference since onlining failed. */
373 put_device(&cdev->dev);
376 /* Wait until a final state is reached */
377 while (!dev_fsm_final_state(cdev)) {
378 spin_unlock_irq(cdev->ccwlock);
379 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
380 spin_lock_irq(cdev->ccwlock);
382 /* Check if online processing was successful */
383 if ((cdev->private->state != DEV_STATE_ONLINE) &&
384 (cdev->private->state != DEV_STATE_W4SENSE)) {
385 spin_unlock_irq(cdev->ccwlock);
386 /* Inform the user that set online failed. */
387 if (cdev->private->state == DEV_STATE_BOXED) {
388 pr_warn("%s: Setting the device online failed because it is boxed\n",
389 dev_name(&cdev->dev));
390 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
391 pr_warn("%s: Setting the device online failed because it is not operational\n",
392 dev_name(&cdev->dev));
394 /* Give up online reference since onlining failed. */
395 put_device(&cdev->dev);
398 spin_unlock_irq(cdev->ccwlock);
399 if (cdev->drv->set_online)
400 ret = cdev->drv->set_online(cdev);
404 spin_lock_irq(cdev->ccwlock);
406 spin_unlock_irq(cdev->ccwlock);
410 spin_lock_irq(cdev->ccwlock);
411 /* Wait until a final state or DISCONNECTED is reached */
412 while (!dev_fsm_final_state(cdev) &&
413 cdev->private->state != DEV_STATE_DISCONNECTED) {
414 spin_unlock_irq(cdev->ccwlock);
415 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
416 cdev->private->state == DEV_STATE_DISCONNECTED));
417 spin_lock_irq(cdev->ccwlock);
419 ret2 = ccw_device_offline(cdev);
422 spin_unlock_irq(cdev->ccwlock);
423 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
424 cdev->private->state == DEV_STATE_DISCONNECTED));
425 /* Give up online reference since onlining failed. */
426 put_device(&cdev->dev);
430 CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
431 "device 0.%x.%04x\n",
432 ret2, cdev->private->dev_id.ssid,
433 cdev->private->dev_id.devno);
434 cdev->private->state = DEV_STATE_OFFLINE;
435 spin_unlock_irq(cdev->ccwlock);
436 /* Give up online reference since onlining failed. */
437 put_device(&cdev->dev);
441 static int online_store_handle_offline(struct ccw_device *cdev)
443 if (cdev->private->state == DEV_STATE_DISCONNECTED) {
444 spin_lock_irq(cdev->ccwlock);
445 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
446 spin_unlock_irq(cdev->ccwlock);
449 if (cdev->drv && cdev->drv->set_offline)
450 return ccw_device_set_offline(cdev);
454 static int online_store_recog_and_online(struct ccw_device *cdev)
456 /* Do device recognition, if needed. */
457 if (cdev->private->state == DEV_STATE_BOXED) {
458 spin_lock_irq(cdev->ccwlock);
459 ccw_device_recognition(cdev);
460 spin_unlock_irq(cdev->ccwlock);
461 wait_event(cdev->private->wait_q,
462 cdev->private->flags.recog_done);
463 if (cdev->private->state != DEV_STATE_OFFLINE)
464 /* recognition failed */
467 if (cdev->drv && cdev->drv->set_online)
468 return ccw_device_set_online(cdev);
472 static int online_store_handle_online(struct ccw_device *cdev, int force)
476 ret = online_store_recog_and_online(cdev);
479 if (force && cdev->private->state == DEV_STATE_BOXED) {
480 ret = ccw_device_stlck(cdev);
483 if (cdev->id.cu_type == 0)
484 cdev->private->state = DEV_STATE_NOT_OPER;
485 ret = online_store_recog_and_online(cdev);
492 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
493 const char *buf, size_t count)
495 struct ccw_device *cdev = to_ccwdev(dev);
499 /* Prevent conflict between multiple on-/offline processing requests. */
500 if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
502 /* Prevent conflict between internal I/Os and on-/offline processing. */
503 if (!dev_fsm_final_state(cdev) &&
504 cdev->private->state != DEV_STATE_DISCONNECTED) {
508 /* Prevent conflict between pending work and on-/offline processing.*/
509 if (work_pending(&cdev->private->todo_work)) {
513 if (!strncmp(buf, "force\n", count)) {
519 ret = kstrtoul(buf, 16, &i);
527 ret = online_store_handle_offline(cdev);
530 ret = online_store_handle_online(cdev, force);
538 atomic_set(&cdev->private->onoff, 0);
539 return (ret < 0) ? ret : count;
543 available_show (struct device *dev, struct device_attribute *attr, char *buf)
545 struct ccw_device *cdev = to_ccwdev(dev);
546 struct subchannel *sch;
548 if (ccw_device_is_orphan(cdev))
549 return sprintf(buf, "no device\n");
550 switch (cdev->private->state) {
551 case DEV_STATE_BOXED:
552 return sprintf(buf, "boxed\n");
553 case DEV_STATE_DISCONNECTED:
554 case DEV_STATE_DISCONNECTED_SENSE_ID:
555 case DEV_STATE_NOT_OPER:
556 sch = to_subchannel(dev->parent);
558 return sprintf(buf, "no path\n");
560 return sprintf(buf, "no device\n");
562 /* All other states considered fine. */
563 return sprintf(buf, "good\n");
568 initiate_logging(struct device *dev, struct device_attribute *attr,
569 const char *buf, size_t count)
571 struct subchannel *sch = to_subchannel(dev);
574 rc = chsc_siosl(sch->schid);
576 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
577 sch->schid.ssid, sch->schid.sch_no, rc);
580 pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
581 sch->schid.ssid, sch->schid.sch_no);
585 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
588 struct subchannel *sch = to_subchannel(dev);
590 return sprintf(buf, "%02x\n", sch->vpm);
593 static DEVICE_ATTR_RO(devtype);
594 static DEVICE_ATTR_RO(cutype);
595 static DEVICE_ATTR_RO(modalias);
596 static DEVICE_ATTR_RW(online);
597 static DEVICE_ATTR(availability, 0444, available_show, NULL);
598 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
599 static DEVICE_ATTR_RO(vpm);
601 static struct attribute *io_subchannel_attrs[] = {
602 &dev_attr_logging.attr,
607 static const struct attribute_group io_subchannel_attr_group = {
608 .attrs = io_subchannel_attrs,
611 static struct attribute * ccwdev_attrs[] = {
612 &dev_attr_devtype.attr,
613 &dev_attr_cutype.attr,
614 &dev_attr_modalias.attr,
615 &dev_attr_online.attr,
616 &dev_attr_cmb_enable.attr,
617 &dev_attr_availability.attr,
621 static const struct attribute_group ccwdev_attr_group = {
622 .attrs = ccwdev_attrs,
625 static const struct attribute_group *ccwdev_attr_groups[] = {
630 static int match_dev_id(struct device *dev, const void *data)
632 struct ccw_device *cdev = to_ccwdev(dev);
633 struct ccw_dev_id *dev_id = (void *)data;
635 return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
639 * get_ccwdev_by_dev_id() - obtain device from a ccw device id
640 * @dev_id: id of the device to be searched
642 * This function searches all devices attached to the ccw bus for a device
645 * If a device is found its reference count is increased and returned;
646 * else %NULL is returned.
648 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
652 dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
654 return dev ? to_ccwdev(dev) : NULL;
656 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
658 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
662 mutex_lock(&cdev->reg_mutex);
663 if (device_is_registered(&cdev->dev)) {
664 device_release_driver(&cdev->dev);
665 ret = device_attach(&cdev->dev);
666 WARN_ON(ret == -ENODEV);
668 mutex_unlock(&cdev->reg_mutex);
672 ccw_device_release(struct device *dev)
674 struct ccw_device *cdev;
676 cdev = to_ccwdev(dev);
677 cio_gp_dma_free(cdev->private->dma_pool, cdev->private->dma_area,
678 sizeof(*cdev->private->dma_area));
679 cio_gp_dma_destroy(cdev->private->dma_pool, &cdev->dev);
680 /* Release reference of parent subchannel. */
681 put_device(cdev->dev.parent);
682 kfree(cdev->private);
686 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
688 struct ccw_device *cdev;
689 struct gen_pool *dma_pool;
692 cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
697 cdev->private = kzalloc(sizeof(struct ccw_device_private),
698 GFP_KERNEL | GFP_DMA);
699 if (!cdev->private) {
704 cdev->dev.dma_mask = sch->dev.dma_mask;
705 ret = dma_set_coherent_mask(&cdev->dev, sch->dev.coherent_dma_mask);
707 goto err_coherent_mask;
709 dma_pool = cio_gp_dma_create(&cdev->dev, 1);
714 cdev->private->dma_pool = dma_pool;
715 cdev->private->dma_area = cio_gp_dma_zalloc(dma_pool, &cdev->dev,
716 sizeof(*cdev->private->dma_area));
717 if (!cdev->private->dma_area) {
723 cio_gp_dma_destroy(dma_pool, &cdev->dev);
726 kfree(cdev->private);
733 static void ccw_device_todo(struct work_struct *work);
735 static int io_subchannel_initialize_dev(struct subchannel *sch,
736 struct ccw_device *cdev)
738 struct ccw_device_private *priv = cdev->private;
742 priv->int_class = IRQIO_CIO;
743 priv->state = DEV_STATE_NOT_OPER;
744 priv->dev_id.devno = sch->schib.pmcw.dev;
745 priv->dev_id.ssid = sch->schid.ssid;
747 INIT_WORK(&priv->todo_work, ccw_device_todo);
748 INIT_LIST_HEAD(&priv->cmb_list);
749 init_waitqueue_head(&priv->wait_q);
750 timer_setup(&priv->timer, ccw_device_timeout, 0);
751 mutex_init(&cdev->reg_mutex);
753 atomic_set(&priv->onoff, 0);
754 cdev->ccwlock = &sch->lock;
755 cdev->dev.parent = &sch->dev;
756 cdev->dev.release = ccw_device_release;
757 cdev->dev.bus = &ccw_bus_type;
758 cdev->dev.groups = ccwdev_attr_groups;
759 /* Do first half of device_register. */
760 device_initialize(&cdev->dev);
761 ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
762 cdev->private->dev_id.devno);
765 if (!get_device(&sch->dev)) {
769 priv->flags.initialized = 1;
770 spin_lock_irq(&sch->lock);
771 sch_set_cdev(sch, cdev);
772 spin_unlock_irq(&sch->lock);
776 /* Release reference from device_initialize(). */
777 put_device(&cdev->dev);
781 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
783 struct ccw_device *cdev;
786 cdev = io_subchannel_allocate_dev(sch);
788 ret = io_subchannel_initialize_dev(sch, cdev);
795 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
797 static void sch_create_and_recog_new_device(struct subchannel *sch)
799 struct ccw_device *cdev;
801 /* Need to allocate a new ccw device. */
802 cdev = io_subchannel_create_ccwdev(sch);
804 /* OK, we did everything we could... */
805 css_sch_device_unregister(sch);
808 /* Start recognition for the new ccw device. */
809 io_subchannel_recog(cdev, sch);
813 * Register recognized device.
815 static void io_subchannel_register(struct ccw_device *cdev)
817 struct subchannel *sch;
818 int ret, adjust_init_count = 1;
821 sch = to_subchannel(cdev->dev.parent);
823 * Check if subchannel is still registered. It may have become
824 * unregistered if a machine check hit us after finishing
825 * device recognition but before the register work could be
828 if (!device_is_registered(&sch->dev))
830 css_update_ssd_info(sch);
832 * io_subchannel_register() will also be called after device
833 * recognition has been done for a boxed device (which will already
834 * be registered). We need to reprobe since we may now have sense id
837 mutex_lock(&cdev->reg_mutex);
838 if (device_is_registered(&cdev->dev)) {
840 ret = device_reprobe(&cdev->dev);
842 /* We can't do much here. */
843 CIO_MSG_EVENT(0, "device_reprobe() returned"
844 " %d for 0.%x.%04x\n", ret,
845 cdev->private->dev_id.ssid,
846 cdev->private->dev_id.devno);
848 adjust_init_count = 0;
851 /* make it known to the system */
852 ret = device_add(&cdev->dev);
854 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
855 cdev->private->dev_id.ssid,
856 cdev->private->dev_id.devno, ret);
857 spin_lock_irqsave(&sch->lock, flags);
858 sch_set_cdev(sch, NULL);
859 spin_unlock_irqrestore(&sch->lock, flags);
860 mutex_unlock(&cdev->reg_mutex);
861 /* Release initial device reference. */
862 put_device(&cdev->dev);
866 cdev->private->flags.recog_done = 1;
867 mutex_unlock(&cdev->reg_mutex);
868 wake_up(&cdev->private->wait_q);
870 if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
871 wake_up(&ccw_device_init_wq);
875 * subchannel recognition done. Called from the state machine.
878 io_subchannel_recog_done(struct ccw_device *cdev)
880 if (css_init_done == 0) {
881 cdev->private->flags.recog_done = 1;
884 switch (cdev->private->state) {
885 case DEV_STATE_BOXED:
886 /* Device did not respond in time. */
887 case DEV_STATE_NOT_OPER:
888 cdev->private->flags.recog_done = 1;
889 /* Remove device found not operational. */
890 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
891 if (atomic_dec_and_test(&ccw_device_init_count))
892 wake_up(&ccw_device_init_wq);
894 case DEV_STATE_OFFLINE:
896 * We can't register the device in interrupt context so
897 * we schedule a work item.
899 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
904 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
906 /* Increase counter of devices currently in recognition. */
907 atomic_inc(&ccw_device_init_count);
909 /* Start async. device sensing. */
910 spin_lock_irq(&sch->lock);
911 ccw_device_recognition(cdev);
912 spin_unlock_irq(&sch->lock);
915 static int ccw_device_move_to_sch(struct ccw_device *cdev,
916 struct subchannel *sch)
918 struct subchannel *old_sch;
919 int rc, old_enabled = 0;
921 old_sch = to_subchannel(cdev->dev.parent);
922 /* Obtain child reference for new parent. */
923 if (!get_device(&sch->dev))
926 if (!sch_is_pseudo_sch(old_sch)) {
927 spin_lock_irq(&old_sch->lock);
928 old_enabled = old_sch->schib.pmcw.ena;
931 rc = cio_disable_subchannel(old_sch);
932 spin_unlock_irq(&old_sch->lock);
934 /* Release child reference for new parent. */
935 put_device(&sch->dev);
940 mutex_lock(&sch->reg_mutex);
941 rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
942 mutex_unlock(&sch->reg_mutex);
944 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
945 cdev->private->dev_id.ssid,
946 cdev->private->dev_id.devno, sch->schid.ssid,
947 sch->schib.pmcw.dev, rc);
949 /* Try to re-enable the old subchannel. */
950 spin_lock_irq(&old_sch->lock);
951 cio_enable_subchannel(old_sch, (u32)virt_to_phys(old_sch));
952 spin_unlock_irq(&old_sch->lock);
954 /* Release child reference for new parent. */
955 put_device(&sch->dev);
958 /* Clean up old subchannel. */
959 if (!sch_is_pseudo_sch(old_sch)) {
960 spin_lock_irq(&old_sch->lock);
961 sch_set_cdev(old_sch, NULL);
962 spin_unlock_irq(&old_sch->lock);
963 css_schedule_eval(old_sch->schid);
965 /* Release child reference for old parent. */
966 put_device(&old_sch->dev);
967 /* Initialize new subchannel. */
968 spin_lock_irq(&sch->lock);
969 cdev->ccwlock = &sch->lock;
970 if (!sch_is_pseudo_sch(sch))
971 sch_set_cdev(sch, cdev);
972 spin_unlock_irq(&sch->lock);
973 if (!sch_is_pseudo_sch(sch))
974 css_update_ssd_info(sch);
978 static int ccw_device_move_to_orph(struct ccw_device *cdev)
980 struct subchannel *sch = to_subchannel(cdev->dev.parent);
981 struct channel_subsystem *css = to_css(sch->dev.parent);
983 return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
986 static void io_subchannel_irq(struct subchannel *sch)
988 struct ccw_device *cdev;
990 cdev = sch_get_cdev(sch);
992 CIO_TRACE_EVENT(6, "IRQ");
993 CIO_TRACE_EVENT(6, dev_name(&sch->dev));
995 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
997 inc_irq_stat(IRQIO_CIO);
1000 void io_subchannel_init_config(struct subchannel *sch)
1002 memset(&sch->config, 0, sizeof(sch->config));
1003 sch->config.csense = 1;
1006 static void io_subchannel_init_fields(struct subchannel *sch)
1008 if (cio_is_console(sch->schid))
1011 sch->opm = chp_get_sch_opm(sch);
1012 sch->lpm = sch->schib.pmcw.pam & sch->opm;
1013 sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1015 CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1016 " - PIM = %02X, PAM = %02X, POM = %02X\n",
1017 sch->schib.pmcw.dev, sch->schid.ssid,
1018 sch->schid.sch_no, sch->schib.pmcw.pim,
1019 sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1021 io_subchannel_init_config(sch);
1025 * Note: We always return 0 so that we bind to the device even on error.
1026 * This is needed so that our remove function is called on unregister.
1028 static int io_subchannel_probe(struct subchannel *sch)
1030 struct io_subchannel_private *io_priv;
1031 struct ccw_device *cdev;
1034 if (cio_is_console(sch->schid)) {
1035 rc = sysfs_create_group(&sch->dev.kobj,
1036 &io_subchannel_attr_group);
1038 CIO_MSG_EVENT(0, "Failed to create io subchannel "
1039 "attributes for subchannel "
1040 "0.%x.%04x (rc=%d)\n",
1041 sch->schid.ssid, sch->schid.sch_no, rc);
1043 * The console subchannel already has an associated ccw_device.
1044 * Register it and exit.
1046 cdev = sch_get_cdev(sch);
1047 rc = device_add(&cdev->dev);
1049 /* Release online reference. */
1050 put_device(&cdev->dev);
1053 if (atomic_dec_and_test(&ccw_device_init_count))
1054 wake_up(&ccw_device_init_wq);
1057 io_subchannel_init_fields(sch);
1058 rc = cio_commit_config(sch);
1061 rc = sysfs_create_group(&sch->dev.kobj,
1062 &io_subchannel_attr_group);
1065 /* Allocate I/O subchannel private data. */
1066 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1070 io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1071 sizeof(*io_priv->dma_area),
1072 &io_priv->dma_area_dma, GFP_KERNEL);
1073 if (!io_priv->dma_area) {
1078 set_io_private(sch, io_priv);
1079 css_schedule_eval(sch->schid);
1083 spin_lock_irq(&sch->lock);
1084 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1085 spin_unlock_irq(&sch->lock);
1089 static void io_subchannel_remove(struct subchannel *sch)
1091 struct io_subchannel_private *io_priv = to_io_private(sch);
1092 struct ccw_device *cdev;
1094 cdev = sch_get_cdev(sch);
1098 ccw_device_unregister(cdev);
1099 spin_lock_irq(&sch->lock);
1100 sch_set_cdev(sch, NULL);
1101 set_io_private(sch, NULL);
1102 spin_unlock_irq(&sch->lock);
1104 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1105 io_priv->dma_area, io_priv->dma_area_dma);
1107 sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1110 static void io_subchannel_verify(struct subchannel *sch)
1112 struct ccw_device *cdev;
1114 cdev = sch_get_cdev(sch);
1116 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1118 css_schedule_eval(sch->schid);
1121 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1123 struct ccw_device *cdev;
1125 cdev = sch_get_cdev(sch);
1128 if (cio_update_schib(sch))
1130 /* Check for I/O on path. */
1131 if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1133 if (cdev->private->state == DEV_STATE_ONLINE) {
1134 ccw_device_kill_io(cdev);
1140 /* Trigger path verification. */
1141 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1145 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1148 static int io_subchannel_chp_event(struct subchannel *sch,
1149 struct chp_link *link, int event)
1151 struct ccw_device *cdev = sch_get_cdev(sch);
1152 int mask, chpid, valid_bit;
1155 mask = chp_ssd_get_mask(&sch->ssd_info, link);
1163 cdev->private->path_gone_mask |= mask;
1164 io_subchannel_terminate_path(sch, mask);
1170 cdev->private->path_new_mask |= mask;
1171 io_subchannel_verify(sch);
1174 if (cio_update_schib(sch))
1177 cdev->private->path_gone_mask |= mask;
1178 io_subchannel_terminate_path(sch, mask);
1181 if (cio_update_schib(sch))
1183 sch->lpm |= mask & sch->opm;
1185 cdev->private->path_new_mask |= mask;
1186 io_subchannel_verify(sch);
1188 case CHP_FCES_EVENT:
1189 /* Forward Endpoint Security event */
1190 for (chpid = 0, valid_bit = 0x80; chpid < 8; chpid++,
1192 if (mask & valid_bit)
1193 path_event[chpid] = PE_PATH_FCES_EVENT;
1195 path_event[chpid] = PE_NONE;
1197 if (cdev && cdev->drv && cdev->drv->path_event)
1198 cdev->drv->path_event(cdev, path_event);
1204 static void io_subchannel_quiesce(struct subchannel *sch)
1206 struct ccw_device *cdev;
1209 spin_lock_irq(&sch->lock);
1210 cdev = sch_get_cdev(sch);
1211 if (cio_is_console(sch->schid))
1213 if (!sch->schib.pmcw.ena)
1215 ret = cio_disable_subchannel(sch);
1219 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1220 while (ret == -EBUSY) {
1221 cdev->private->state = DEV_STATE_QUIESCE;
1222 cdev->private->iretry = 255;
1223 ret = ccw_device_cancel_halt_clear(cdev);
1224 if (ret == -EBUSY) {
1225 ccw_device_set_timeout(cdev, HZ/10);
1226 spin_unlock_irq(&sch->lock);
1227 wait_event(cdev->private->wait_q,
1228 cdev->private->state != DEV_STATE_QUIESCE);
1229 spin_lock_irq(&sch->lock);
1231 ret = cio_disable_subchannel(sch);
1234 spin_unlock_irq(&sch->lock);
1237 static void io_subchannel_shutdown(struct subchannel *sch)
1239 io_subchannel_quiesce(sch);
1242 static int device_is_disconnected(struct ccw_device *cdev)
1246 return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1247 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1250 static int recovery_check(struct device *dev, void *data)
1252 struct ccw_device *cdev = to_ccwdev(dev);
1253 struct subchannel *sch;
1256 spin_lock_irq(cdev->ccwlock);
1257 switch (cdev->private->state) {
1258 case DEV_STATE_ONLINE:
1259 sch = to_subchannel(cdev->dev.parent);
1260 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1263 case DEV_STATE_DISCONNECTED:
1264 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1265 cdev->private->dev_id.ssid,
1266 cdev->private->dev_id.devno);
1267 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1270 case DEV_STATE_DISCONNECTED_SENSE_ID:
1274 spin_unlock_irq(cdev->ccwlock);
1279 static void recovery_work_func(struct work_struct *unused)
1283 bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1285 spin_lock_irq(&recovery_lock);
1286 if (!timer_pending(&recovery_timer)) {
1287 if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1289 mod_timer(&recovery_timer, jiffies +
1290 recovery_delay[recovery_phase] * HZ);
1292 spin_unlock_irq(&recovery_lock);
1294 CIO_MSG_EVENT(3, "recovery: end\n");
1297 static DECLARE_WORK(recovery_work, recovery_work_func);
1299 static void recovery_func(struct timer_list *unused)
1302 * We can't do our recovery in softirq context and it's not
1303 * performance critical, so we schedule it.
1305 schedule_work(&recovery_work);
1308 void ccw_device_schedule_recovery(void)
1310 unsigned long flags;
1312 CIO_MSG_EVENT(3, "recovery: schedule\n");
1313 spin_lock_irqsave(&recovery_lock, flags);
1314 if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1316 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1318 spin_unlock_irqrestore(&recovery_lock, flags);
1321 static int purge_fn(struct device *dev, void *data)
1323 struct ccw_device *cdev = to_ccwdev(dev);
1324 struct ccw_dev_id *id = &cdev->private->dev_id;
1325 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1327 spin_lock_irq(cdev->ccwlock);
1328 if (is_blacklisted(id->ssid, id->devno) &&
1329 (cdev->private->state == DEV_STATE_OFFLINE) &&
1330 (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1331 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1333 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1334 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1335 atomic_set(&cdev->private->onoff, 0);
1337 spin_unlock_irq(cdev->ccwlock);
1338 /* Abort loop in case of pending signal. */
1339 if (signal_pending(current))
1346 * ccw_purge_blacklisted - purge unused, blacklisted devices
1348 * Unregister all ccw devices that are offline and on the blacklist.
1350 int ccw_purge_blacklisted(void)
1352 CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1353 bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1357 void ccw_device_set_disconnected(struct ccw_device *cdev)
1361 ccw_device_set_timeout(cdev, 0);
1362 cdev->private->flags.fake_irb = 0;
1363 cdev->private->state = DEV_STATE_DISCONNECTED;
1365 ccw_device_schedule_recovery();
1368 void ccw_device_set_notoper(struct ccw_device *cdev)
1370 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1372 CIO_TRACE_EVENT(2, "notoper");
1373 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1374 ccw_device_set_timeout(cdev, 0);
1375 cio_disable_subchannel(sch);
1376 cdev->private->state = DEV_STATE_NOT_OPER;
1379 enum io_sch_action {
1384 IO_SCH_UNREG_ATTACH,
1392 static enum io_sch_action sch_get_action(struct subchannel *sch)
1394 struct ccw_device *cdev;
1396 cdev = sch_get_cdev(sch);
1397 if (cio_update_schib(sch)) {
1398 /* Not operational. */
1400 return IO_SCH_UNREG;
1401 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1402 return IO_SCH_UNREG;
1403 return IO_SCH_ORPH_UNREG;
1407 return IO_SCH_ATTACH;
1408 if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1409 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1410 return IO_SCH_UNREG_ATTACH;
1411 return IO_SCH_ORPH_ATTACH;
1413 if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1414 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1415 return IO_SCH_UNREG_CDEV;
1418 if (device_is_disconnected(cdev))
1419 return IO_SCH_REPROBE;
1421 return IO_SCH_VERIFY;
1422 if (cdev->private->state == DEV_STATE_NOT_OPER)
1423 return IO_SCH_UNREG_ATTACH;
1428 * io_subchannel_sch_event - process subchannel event
1430 * @process: non-zero if function is called in process context
1432 * An unspecified event occurred for this subchannel. Adjust data according
1433 * to the current operational state of the subchannel and device. Return
1434 * zero when the event has been handled sufficiently or -EAGAIN when this
1435 * function should be called again in process context.
1437 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1439 unsigned long flags;
1440 struct ccw_device *cdev;
1441 struct ccw_dev_id dev_id;
1442 enum io_sch_action action;
1445 spin_lock_irqsave(&sch->lock, flags);
1446 if (!device_is_registered(&sch->dev))
1448 if (work_pending(&sch->todo_work))
1450 cdev = sch_get_cdev(sch);
1451 if (cdev && work_pending(&cdev->private->todo_work))
1453 action = sch_get_action(sch);
1454 CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1455 sch->schid.ssid, sch->schid.sch_no, process,
1457 /* Perform immediate actions while holding the lock. */
1459 case IO_SCH_REPROBE:
1460 /* Trigger device recognition. */
1461 ccw_device_trigger_reprobe(cdev);
1465 /* Trigger path verification. */
1466 io_subchannel_verify(sch);
1470 ccw_device_set_disconnected(cdev);
1473 case IO_SCH_ORPH_UNREG:
1474 case IO_SCH_ORPH_ATTACH:
1475 ccw_device_set_disconnected(cdev);
1477 case IO_SCH_UNREG_CDEV:
1478 case IO_SCH_UNREG_ATTACH:
1482 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1484 * Note: delayed work triggered by this event
1485 * and repeated calls to sch_event are synchronized
1486 * by the above check for work_pending(cdev).
1488 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1490 ccw_device_set_notoper(cdev);
1498 spin_unlock_irqrestore(&sch->lock, flags);
1499 /* All other actions require process context. */
1502 /* Handle attached ccw device. */
1504 case IO_SCH_ORPH_UNREG:
1505 case IO_SCH_ORPH_ATTACH:
1506 /* Move ccw device to orphanage. */
1507 rc = ccw_device_move_to_orph(cdev);
1511 case IO_SCH_UNREG_CDEV:
1512 case IO_SCH_UNREG_ATTACH:
1513 spin_lock_irqsave(&sch->lock, flags);
1514 sch_set_cdev(sch, NULL);
1515 spin_unlock_irqrestore(&sch->lock, flags);
1516 /* Unregister ccw device. */
1517 ccw_device_unregister(cdev);
1522 /* Handle subchannel. */
1524 case IO_SCH_ORPH_UNREG:
1526 css_sch_device_unregister(sch);
1528 case IO_SCH_ORPH_ATTACH:
1529 case IO_SCH_UNREG_ATTACH:
1531 dev_id.ssid = sch->schid.ssid;
1532 dev_id.devno = sch->schib.pmcw.dev;
1533 cdev = get_ccwdev_by_dev_id(&dev_id);
1535 sch_create_and_recog_new_device(sch);
1538 rc = ccw_device_move_to_sch(cdev, sch);
1540 /* Release reference from get_ccwdev_by_dev_id() */
1541 put_device(&cdev->dev);
1544 spin_lock_irqsave(&sch->lock, flags);
1545 ccw_device_trigger_reprobe(cdev);
1546 spin_unlock_irqrestore(&sch->lock, flags);
1547 /* Release reference from get_ccwdev_by_dev_id() */
1548 put_device(&cdev->dev);
1556 spin_unlock_irqrestore(&sch->lock, flags);
1561 static void ccw_device_set_int_class(struct ccw_device *cdev)
1563 struct ccw_driver *cdrv = cdev->drv;
1565 /* Note: we interpret class 0 in this context as an uninitialized
1566 * field since it translates to a non-I/O interrupt class. */
1567 if (cdrv->int_class != 0)
1568 cdev->private->int_class = cdrv->int_class;
1570 cdev->private->int_class = IRQIO_CIO;
1573 #ifdef CONFIG_CCW_CONSOLE
1574 int __init ccw_device_enable_console(struct ccw_device *cdev)
1576 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1579 if (!cdev->drv || !cdev->handler)
1582 io_subchannel_init_fields(sch);
1583 rc = cio_commit_config(sch);
1586 sch->driver = &io_subchannel_driver;
1587 io_subchannel_recog(cdev, sch);
1588 /* Now wait for the async. recognition to come to an end. */
1589 spin_lock_irq(cdev->ccwlock);
1590 while (!dev_fsm_final_state(cdev))
1591 ccw_device_wait_idle(cdev);
1593 /* Hold on to an extra reference while device is online. */
1594 get_device(&cdev->dev);
1595 rc = ccw_device_online(cdev);
1599 while (!dev_fsm_final_state(cdev))
1600 ccw_device_wait_idle(cdev);
1602 if (cdev->private->state == DEV_STATE_ONLINE)
1607 spin_unlock_irq(cdev->ccwlock);
1608 if (rc) /* Give up online reference since onlining failed. */
1609 put_device(&cdev->dev);
1613 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1615 struct io_subchannel_private *io_priv;
1616 struct ccw_device *cdev;
1617 struct subchannel *sch;
1619 sch = cio_probe_console();
1621 return ERR_CAST(sch);
1623 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1626 io_priv->dma_area = dma_alloc_coherent(&sch->dev,
1627 sizeof(*io_priv->dma_area),
1628 &io_priv->dma_area_dma, GFP_KERNEL);
1629 if (!io_priv->dma_area)
1631 set_io_private(sch, io_priv);
1632 cdev = io_subchannel_create_ccwdev(sch);
1634 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1635 io_priv->dma_area, io_priv->dma_area_dma);
1636 set_io_private(sch, NULL);
1637 put_device(&sch->dev);
1642 ccw_device_set_int_class(cdev);
1648 put_device(&sch->dev);
1649 return ERR_PTR(-ENOMEM);
1652 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1654 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1655 struct io_subchannel_private *io_priv = to_io_private(sch);
1657 set_io_private(sch, NULL);
1658 dma_free_coherent(&sch->dev, sizeof(*io_priv->dma_area),
1659 io_priv->dma_area, io_priv->dma_area_dma);
1660 put_device(&sch->dev);
1661 put_device(&cdev->dev);
1666 * ccw_device_wait_idle() - busy wait for device to become idle
1669 * Poll until activity control is zero, that is, no function or data
1670 * transfer is pending/active.
1671 * Called with device lock being held.
1673 void ccw_device_wait_idle(struct ccw_device *cdev)
1675 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1679 if (sch->schib.scsw.cmd.actl == 0)
1687 * get_ccwdev_by_busid() - obtain device from a bus id
1688 * @cdrv: driver the device is owned by
1689 * @bus_id: bus id of the device to be searched
1691 * This function searches all devices owned by @cdrv for a device with a bus
1692 * id matching @bus_id.
1694 * If a match is found, its reference count of the found device is increased
1695 * and it is returned; else %NULL is returned.
1697 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1702 dev = driver_find_device_by_name(&cdrv->driver, bus_id);
1704 return dev ? to_ccwdev(dev) : NULL;
1707 /************************** device driver handling ************************/
1709 /* This is the implementation of the ccw_driver class. The probe, remove
1710 * and release methods are initially very similar to the device_driver
1711 * implementations, with the difference that they have ccw_device
1714 * A ccw driver also contains the information that is needed for
1718 ccw_device_probe (struct device *dev)
1720 struct ccw_device *cdev = to_ccwdev(dev);
1721 struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1724 cdev->drv = cdrv; /* to let the driver call _set_online */
1725 ccw_device_set_int_class(cdev);
1726 ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1729 cdev->private->int_class = IRQIO_CIO;
1736 static void ccw_device_remove(struct device *dev)
1738 struct ccw_device *cdev = to_ccwdev(dev);
1739 struct ccw_driver *cdrv = cdev->drv;
1740 struct subchannel *sch;
1746 spin_lock_irq(cdev->ccwlock);
1749 ret = ccw_device_offline(cdev);
1750 spin_unlock_irq(cdev->ccwlock);
1752 wait_event(cdev->private->wait_q,
1753 dev_fsm_final_state(cdev));
1755 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1756 "device 0.%x.%04x\n",
1757 ret, cdev->private->dev_id.ssid,
1758 cdev->private->dev_id.devno);
1759 /* Give up reference obtained in ccw_device_set_online(). */
1760 put_device(&cdev->dev);
1761 spin_lock_irq(cdev->ccwlock);
1763 ccw_device_set_timeout(cdev, 0);
1765 cdev->private->int_class = IRQIO_CIO;
1766 sch = to_subchannel(cdev->dev.parent);
1767 spin_unlock_irq(cdev->ccwlock);
1768 io_subchannel_quiesce(sch);
1769 __disable_cmf(cdev);
1772 static void ccw_device_shutdown(struct device *dev)
1774 struct ccw_device *cdev;
1776 cdev = to_ccwdev(dev);
1777 if (cdev->drv && cdev->drv->shutdown)
1778 cdev->drv->shutdown(cdev);
1779 __disable_cmf(cdev);
1782 static struct bus_type ccw_bus_type = {
1784 .match = ccw_bus_match,
1785 .uevent = ccw_uevent,
1786 .probe = ccw_device_probe,
1787 .remove = ccw_device_remove,
1788 .shutdown = ccw_device_shutdown,
1792 * ccw_driver_register() - register a ccw driver
1793 * @cdriver: driver to be registered
1795 * This function is mainly a wrapper around driver_register().
1797 * %0 on success and a negative error value on failure.
1799 int ccw_driver_register(struct ccw_driver *cdriver)
1801 struct device_driver *drv = &cdriver->driver;
1803 drv->bus = &ccw_bus_type;
1805 return driver_register(drv);
1809 * ccw_driver_unregister() - deregister a ccw driver
1810 * @cdriver: driver to be deregistered
1812 * This function is mainly a wrapper around driver_unregister().
1814 void ccw_driver_unregister(struct ccw_driver *cdriver)
1816 driver_unregister(&cdriver->driver);
1819 static void ccw_device_todo(struct work_struct *work)
1821 struct ccw_device_private *priv;
1822 struct ccw_device *cdev;
1823 struct subchannel *sch;
1824 enum cdev_todo todo;
1826 priv = container_of(work, struct ccw_device_private, todo_work);
1828 sch = to_subchannel(cdev->dev.parent);
1829 /* Find out todo. */
1830 spin_lock_irq(cdev->ccwlock);
1832 priv->todo = CDEV_TODO_NOTHING;
1833 CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1834 priv->dev_id.ssid, priv->dev_id.devno, todo);
1835 spin_unlock_irq(cdev->ccwlock);
1838 case CDEV_TODO_ENABLE_CMF:
1841 case CDEV_TODO_REBIND:
1842 ccw_device_do_unbind_bind(cdev);
1844 case CDEV_TODO_REGISTER:
1845 io_subchannel_register(cdev);
1847 case CDEV_TODO_UNREG_EVAL:
1848 if (!sch_is_pseudo_sch(sch))
1849 css_schedule_eval(sch->schid);
1851 case CDEV_TODO_UNREG:
1852 spin_lock_irq(&sch->lock);
1853 sch_set_cdev(sch, NULL);
1854 spin_unlock_irq(&sch->lock);
1855 ccw_device_unregister(cdev);
1860 /* Release workqueue ref. */
1861 put_device(&cdev->dev);
1865 * ccw_device_sched_todo - schedule ccw device operation
1869 * Schedule the operation identified by @todo to be performed on the slow path
1870 * workqueue. Do nothing if another operation with higher priority is already
1871 * scheduled. Needs to be called with ccwdev lock held.
1873 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
1875 CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
1876 cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
1878 if (cdev->private->todo >= todo)
1880 cdev->private->todo = todo;
1881 /* Get workqueue ref. */
1882 if (!get_device(&cdev->dev))
1884 if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
1885 /* Already queued, release workqueue ref. */
1886 put_device(&cdev->dev);
1891 * ccw_device_siosl() - initiate logging
1894 * This function is used to invoke model-dependent logging within the channel
1897 int ccw_device_siosl(struct ccw_device *cdev)
1899 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1901 return chsc_siosl(sch->schid);
1903 EXPORT_SYMBOL_GPL(ccw_device_siosl);
1905 EXPORT_SYMBOL(ccw_device_set_online);
1906 EXPORT_SYMBOL(ccw_device_set_offline);
1907 EXPORT_SYMBOL(ccw_driver_register);
1908 EXPORT_SYMBOL(ccw_driver_unregister);
1909 EXPORT_SYMBOL(get_ccwdev_by_busid);