Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / drivers / s390 / cio / device.c
blobf50ea035aa9b3cf3966a39ee14f7e608c5f9ec54
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
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)
9 */
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>
28 #include <asm/ccwdev.h>
29 #include <asm/cio.h>
30 #include <asm/param.h> /* HZ */
31 #include <asm/cmb.h>
32 #include <asm/isc.h>
34 #include "chp.h"
35 #include "cio.h"
36 #include "cio_debug.h"
37 #include "css.h"
38 #include "device.h"
39 #include "ioasm.h"
40 #include "io_sch.h"
41 #include "blacklist.h"
42 #include "chsc.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. */
59 static int
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;
66 if (!ids)
67 return 0;
69 found = ccw_device_id_match(ids, &cdev->id);
70 if (!found)
71 return 0;
73 cdev->id.driver_info = found->driver_info;
75 return 1;
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)
84 int len;
86 len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
87 if (len > size)
88 return len;
89 buf += len;
90 size -= len;
92 if (id->dev_type != 0)
93 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
94 id->dev_model, suffix);
95 else
96 len += snprintf(buf, size, "dtdm%s", suffix);
98 return len;
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);
107 int ret;
108 char modalias_buf[30];
110 /* CU_TYPE= */
111 ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
112 if (ret)
113 return ret;
115 /* CU_MODEL= */
116 ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
117 if (ret)
118 return ret;
120 /* The next two can be zero, that's ok for us */
121 /* DEV_TYPE= */
122 ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
123 if (ret)
124 return ret;
126 /* DEV_MODEL= */
127 ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
128 if (ret)
129 return ret;
131 /* MODALIAS= */
132 snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
133 ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
134 return ret;
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 *,
143 int);
144 static void recovery_func(struct timer_list *unused);
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))
160 return -EAGAIN;
161 return 0;
164 static int io_subchannel_settle(void)
166 int ret;
168 ret = wait_event_interruptible(ccw_device_init_wq,
169 atomic_read(&ccw_device_init_count) == 0);
170 if (ret)
171 return -EINTR;
172 flush_workqueue(cio_work_q);
173 return 0;
176 static struct css_driver io_subchannel_driver = {
177 .drv = {
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)
194 int ret;
196 timer_setup(&recovery_timer, recovery_func, 0);
197 ret = bus_register(&ccw_bus_type);
198 if (ret)
199 return ret;
200 ret = css_driver_register(&io_subchannel_driver);
201 if (ret)
202 bus_unregister(&ccw_bus_type);
204 return ret;
208 /************************ device handling **************************/
210 static ssize_t
211 devtype_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 if (id->dev_type != 0)
217 return sprintf(buf, "%04x/%02x\n",
218 id->dev_type, id->dev_model);
219 else
220 return sprintf(buf, "n/a\n");
223 static ssize_t
224 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
226 struct ccw_device *cdev = to_ccwdev(dev);
227 struct ccw_device_id *id = &(cdev->id);
229 return sprintf(buf, "%04x/%02x\n",
230 id->cu_type, id->cu_model);
233 static ssize_t
234 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
236 struct ccw_device *cdev = to_ccwdev(dev);
237 struct ccw_device_id *id = &(cdev->id);
238 int len;
240 len = snprint_alias(buf, PAGE_SIZE, id, "\n");
242 return len > PAGE_SIZE ? PAGE_SIZE : len;
245 static ssize_t
246 online_show (struct device *dev, struct device_attribute *attr, char *buf)
248 struct ccw_device *cdev = to_ccwdev(dev);
250 return sprintf(buf, cdev->online ? "1\n" : "0\n");
253 int ccw_device_is_orphan(struct ccw_device *cdev)
255 return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
258 static void ccw_device_unregister(struct ccw_device *cdev)
260 if (device_is_registered(&cdev->dev)) {
261 /* Undo device_add(). */
262 device_del(&cdev->dev);
264 if (cdev->private->flags.initialized) {
265 cdev->private->flags.initialized = 0;
266 /* Release reference from device_initialize(). */
267 put_device(&cdev->dev);
271 static void io_subchannel_quiesce(struct subchannel *);
274 * ccw_device_set_offline() - disable a ccw device for I/O
275 * @cdev: target ccw device
277 * This function calls the driver's set_offline() function for @cdev, if
278 * given, and then disables @cdev.
279 * Returns:
280 * %0 on success and a negative error value on failure.
281 * Context:
282 * enabled, ccw device lock not held
284 int ccw_device_set_offline(struct ccw_device *cdev)
286 struct subchannel *sch;
287 int ret, state;
289 if (!cdev)
290 return -ENODEV;
291 if (!cdev->online || !cdev->drv)
292 return -EINVAL;
294 if (cdev->drv->set_offline) {
295 ret = cdev->drv->set_offline(cdev);
296 if (ret != 0)
297 return ret;
299 spin_lock_irq(cdev->ccwlock);
300 sch = to_subchannel(cdev->dev.parent);
301 cdev->online = 0;
302 /* Wait until a final state or DISCONNECTED is reached */
303 while (!dev_fsm_final_state(cdev) &&
304 cdev->private->state != DEV_STATE_DISCONNECTED) {
305 spin_unlock_irq(cdev->ccwlock);
306 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
307 cdev->private->state == DEV_STATE_DISCONNECTED));
308 spin_lock_irq(cdev->ccwlock);
310 do {
311 ret = ccw_device_offline(cdev);
312 if (!ret)
313 break;
314 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
315 "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
316 cdev->private->dev_id.devno);
317 if (ret != -EBUSY)
318 goto error;
319 state = cdev->private->state;
320 spin_unlock_irq(cdev->ccwlock);
321 io_subchannel_quiesce(sch);
322 spin_lock_irq(cdev->ccwlock);
323 cdev->private->state = state;
324 } while (ret == -EBUSY);
325 spin_unlock_irq(cdev->ccwlock);
326 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
327 cdev->private->state == DEV_STATE_DISCONNECTED));
328 /* Inform the user if set offline failed. */
329 if (cdev->private->state == DEV_STATE_BOXED) {
330 pr_warn("%s: The device entered boxed state while being set offline\n",
331 dev_name(&cdev->dev));
332 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
333 pr_warn("%s: The device stopped operating while being set offline\n",
334 dev_name(&cdev->dev));
336 /* Give up reference from ccw_device_set_online(). */
337 put_device(&cdev->dev);
338 return 0;
340 error:
341 cdev->private->state = DEV_STATE_OFFLINE;
342 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
343 spin_unlock_irq(cdev->ccwlock);
344 /* Give up reference from ccw_device_set_online(). */
345 put_device(&cdev->dev);
346 return -ENODEV;
350 * ccw_device_set_online() - enable a ccw device for I/O
351 * @cdev: target ccw device
353 * This function first enables @cdev and then calls the driver's set_online()
354 * function for @cdev, if given. If set_online() returns an error, @cdev is
355 * disabled again.
356 * Returns:
357 * %0 on success and a negative error value on failure.
358 * Context:
359 * enabled, ccw device lock not held
361 int ccw_device_set_online(struct ccw_device *cdev)
363 int ret;
364 int ret2;
366 if (!cdev)
367 return -ENODEV;
368 if (cdev->online || !cdev->drv)
369 return -EINVAL;
370 /* Hold on to an extra reference while device is online. */
371 if (!get_device(&cdev->dev))
372 return -ENODEV;
374 spin_lock_irq(cdev->ccwlock);
375 ret = ccw_device_online(cdev);
376 spin_unlock_irq(cdev->ccwlock);
377 if (ret == 0)
378 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
379 else {
380 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
381 "device 0.%x.%04x\n",
382 ret, cdev->private->dev_id.ssid,
383 cdev->private->dev_id.devno);
384 /* Give up online reference since onlining failed. */
385 put_device(&cdev->dev);
386 return ret;
388 spin_lock_irq(cdev->ccwlock);
389 /* Check if online processing was successful */
390 if ((cdev->private->state != DEV_STATE_ONLINE) &&
391 (cdev->private->state != DEV_STATE_W4SENSE)) {
392 spin_unlock_irq(cdev->ccwlock);
393 /* Inform the user that set online failed. */
394 if (cdev->private->state == DEV_STATE_BOXED) {
395 pr_warn("%s: Setting the device online failed because it is boxed\n",
396 dev_name(&cdev->dev));
397 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
398 pr_warn("%s: Setting the device online failed because it is not operational\n",
399 dev_name(&cdev->dev));
401 /* Give up online reference since onlining failed. */
402 put_device(&cdev->dev);
403 return -ENODEV;
405 spin_unlock_irq(cdev->ccwlock);
406 if (cdev->drv->set_online)
407 ret = cdev->drv->set_online(cdev);
408 if (ret)
409 goto rollback;
411 spin_lock_irq(cdev->ccwlock);
412 cdev->online = 1;
413 spin_unlock_irq(cdev->ccwlock);
414 return 0;
416 rollback:
417 spin_lock_irq(cdev->ccwlock);
418 /* Wait until a final state or DISCONNECTED is reached */
419 while (!dev_fsm_final_state(cdev) &&
420 cdev->private->state != DEV_STATE_DISCONNECTED) {
421 spin_unlock_irq(cdev->ccwlock);
422 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
423 cdev->private->state == DEV_STATE_DISCONNECTED));
424 spin_lock_irq(cdev->ccwlock);
426 ret2 = ccw_device_offline(cdev);
427 if (ret2)
428 goto error;
429 spin_unlock_irq(cdev->ccwlock);
430 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
431 cdev->private->state == DEV_STATE_DISCONNECTED));
432 /* Give up online reference since onlining failed. */
433 put_device(&cdev->dev);
434 return ret;
436 error:
437 CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
438 "device 0.%x.%04x\n",
439 ret2, cdev->private->dev_id.ssid,
440 cdev->private->dev_id.devno);
441 cdev->private->state = DEV_STATE_OFFLINE;
442 spin_unlock_irq(cdev->ccwlock);
443 /* Give up online reference since onlining failed. */
444 put_device(&cdev->dev);
445 return ret;
448 static int online_store_handle_offline(struct ccw_device *cdev)
450 if (cdev->private->state == DEV_STATE_DISCONNECTED) {
451 spin_lock_irq(cdev->ccwlock);
452 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
453 spin_unlock_irq(cdev->ccwlock);
454 return 0;
456 if (cdev->drv && cdev->drv->set_offline)
457 return ccw_device_set_offline(cdev);
458 return -EINVAL;
461 static int online_store_recog_and_online(struct ccw_device *cdev)
463 /* Do device recognition, if needed. */
464 if (cdev->private->state == DEV_STATE_BOXED) {
465 spin_lock_irq(cdev->ccwlock);
466 ccw_device_recognition(cdev);
467 spin_unlock_irq(cdev->ccwlock);
468 wait_event(cdev->private->wait_q,
469 cdev->private->flags.recog_done);
470 if (cdev->private->state != DEV_STATE_OFFLINE)
471 /* recognition failed */
472 return -EAGAIN;
474 if (cdev->drv && cdev->drv->set_online)
475 return ccw_device_set_online(cdev);
476 return -EINVAL;
479 static int online_store_handle_online(struct ccw_device *cdev, int force)
481 int ret;
483 ret = online_store_recog_and_online(cdev);
484 if (ret && !force)
485 return ret;
486 if (force && cdev->private->state == DEV_STATE_BOXED) {
487 ret = ccw_device_stlck(cdev);
488 if (ret)
489 return ret;
490 if (cdev->id.cu_type == 0)
491 cdev->private->state = DEV_STATE_NOT_OPER;
492 ret = online_store_recog_and_online(cdev);
493 if (ret)
494 return ret;
496 return 0;
499 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
500 const char *buf, size_t count)
502 struct ccw_device *cdev = to_ccwdev(dev);
503 int force, ret;
504 unsigned long i;
506 /* Prevent conflict between multiple on-/offline processing requests. */
507 if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
508 return -EAGAIN;
509 /* Prevent conflict between internal I/Os and on-/offline processing. */
510 if (!dev_fsm_final_state(cdev) &&
511 cdev->private->state != DEV_STATE_DISCONNECTED) {
512 ret = -EAGAIN;
513 goto out;
515 /* Prevent conflict between pending work and on-/offline processing.*/
516 if (work_pending(&cdev->private->todo_work)) {
517 ret = -EAGAIN;
518 goto out;
520 if (!strncmp(buf, "force\n", count)) {
521 force = 1;
522 i = 1;
523 ret = 0;
524 } else {
525 force = 0;
526 ret = kstrtoul(buf, 16, &i);
528 if (ret)
529 goto out;
531 device_lock(dev);
532 switch (i) {
533 case 0:
534 ret = online_store_handle_offline(cdev);
535 break;
536 case 1:
537 ret = online_store_handle_online(cdev, force);
538 break;
539 default:
540 ret = -EINVAL;
542 device_unlock(dev);
544 out:
545 atomic_set(&cdev->private->onoff, 0);
546 return (ret < 0) ? ret : count;
549 static ssize_t
550 available_show (struct device *dev, struct device_attribute *attr, char *buf)
552 struct ccw_device *cdev = to_ccwdev(dev);
553 struct subchannel *sch;
555 if (ccw_device_is_orphan(cdev))
556 return sprintf(buf, "no device\n");
557 switch (cdev->private->state) {
558 case DEV_STATE_BOXED:
559 return sprintf(buf, "boxed\n");
560 case DEV_STATE_DISCONNECTED:
561 case DEV_STATE_DISCONNECTED_SENSE_ID:
562 case DEV_STATE_NOT_OPER:
563 sch = to_subchannel(dev->parent);
564 if (!sch->lpm)
565 return sprintf(buf, "no path\n");
566 else
567 return sprintf(buf, "no device\n");
568 default:
569 /* All other states considered fine. */
570 return sprintf(buf, "good\n");
574 static ssize_t
575 initiate_logging(struct device *dev, struct device_attribute *attr,
576 const char *buf, size_t count)
578 struct subchannel *sch = to_subchannel(dev);
579 int rc;
581 rc = chsc_siosl(sch->schid);
582 if (rc < 0) {
583 pr_warn("Logging for subchannel 0.%x.%04x failed with errno=%d\n",
584 sch->schid.ssid, sch->schid.sch_no, rc);
585 return rc;
587 pr_notice("Logging for subchannel 0.%x.%04x was triggered\n",
588 sch->schid.ssid, sch->schid.sch_no);
589 return count;
592 static ssize_t vpm_show(struct device *dev, struct device_attribute *attr,
593 char *buf)
595 struct subchannel *sch = to_subchannel(dev);
597 return sprintf(buf, "%02x\n", sch->vpm);
600 static DEVICE_ATTR_RO(devtype);
601 static DEVICE_ATTR_RO(cutype);
602 static DEVICE_ATTR_RO(modalias);
603 static DEVICE_ATTR_RW(online);
604 static DEVICE_ATTR(availability, 0444, available_show, NULL);
605 static DEVICE_ATTR(logging, 0200, NULL, initiate_logging);
606 static DEVICE_ATTR_RO(vpm);
608 static struct attribute *io_subchannel_attrs[] = {
609 &dev_attr_logging.attr,
610 &dev_attr_vpm.attr,
611 NULL,
614 static const struct attribute_group io_subchannel_attr_group = {
615 .attrs = io_subchannel_attrs,
618 static struct attribute * ccwdev_attrs[] = {
619 &dev_attr_devtype.attr,
620 &dev_attr_cutype.attr,
621 &dev_attr_modalias.attr,
622 &dev_attr_online.attr,
623 &dev_attr_cmb_enable.attr,
624 &dev_attr_availability.attr,
625 NULL,
628 static const struct attribute_group ccwdev_attr_group = {
629 .attrs = ccwdev_attrs,
632 static const struct attribute_group *ccwdev_attr_groups[] = {
633 &ccwdev_attr_group,
634 NULL,
637 static int ccw_device_add(struct ccw_device *cdev)
639 struct device *dev = &cdev->dev;
641 dev->bus = &ccw_bus_type;
642 return device_add(dev);
645 static int match_dev_id(struct device *dev, void *data)
647 struct ccw_device *cdev = to_ccwdev(dev);
648 struct ccw_dev_id *dev_id = data;
650 return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
654 * get_ccwdev_by_dev_id() - obtain device from a ccw device id
655 * @dev_id: id of the device to be searched
657 * This function searches all devices attached to the ccw bus for a device
658 * matching @dev_id.
659 * Returns:
660 * If a device is found its reference count is increased and returned;
661 * else %NULL is returned.
663 struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
665 struct device *dev;
667 dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
669 return dev ? to_ccwdev(dev) : NULL;
671 EXPORT_SYMBOL_GPL(get_ccwdev_by_dev_id);
673 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
675 int ret;
677 if (device_is_registered(&cdev->dev)) {
678 device_release_driver(&cdev->dev);
679 ret = device_attach(&cdev->dev);
680 WARN_ON(ret == -ENODEV);
684 static void
685 ccw_device_release(struct device *dev)
687 struct ccw_device *cdev;
689 cdev = to_ccwdev(dev);
690 /* Release reference of parent subchannel. */
691 put_device(cdev->dev.parent);
692 kfree(cdev->private);
693 kfree(cdev);
696 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
698 struct ccw_device *cdev;
700 cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
701 if (cdev) {
702 cdev->private = kzalloc(sizeof(struct ccw_device_private),
703 GFP_KERNEL | GFP_DMA);
704 if (cdev->private)
705 return cdev;
707 kfree(cdev);
708 return ERR_PTR(-ENOMEM);
711 static void ccw_device_todo(struct work_struct *work);
713 static int io_subchannel_initialize_dev(struct subchannel *sch,
714 struct ccw_device *cdev)
716 struct ccw_device_private *priv = cdev->private;
717 int ret;
719 priv->cdev = cdev;
720 priv->int_class = IRQIO_CIO;
721 priv->state = DEV_STATE_NOT_OPER;
722 priv->dev_id.devno = sch->schib.pmcw.dev;
723 priv->dev_id.ssid = sch->schid.ssid;
725 INIT_WORK(&priv->todo_work, ccw_device_todo);
726 INIT_LIST_HEAD(&priv->cmb_list);
727 init_waitqueue_head(&priv->wait_q);
728 timer_setup(&priv->timer, ccw_device_timeout, 0);
730 atomic_set(&priv->onoff, 0);
731 cdev->ccwlock = sch->lock;
732 cdev->dev.parent = &sch->dev;
733 cdev->dev.release = ccw_device_release;
734 cdev->dev.groups = ccwdev_attr_groups;
735 /* Do first half of device_register. */
736 device_initialize(&cdev->dev);
737 ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
738 cdev->private->dev_id.devno);
739 if (ret)
740 goto out_put;
741 if (!get_device(&sch->dev)) {
742 ret = -ENODEV;
743 goto out_put;
745 priv->flags.initialized = 1;
746 spin_lock_irq(sch->lock);
747 sch_set_cdev(sch, cdev);
748 spin_unlock_irq(sch->lock);
749 return 0;
751 out_put:
752 /* Release reference from device_initialize(). */
753 put_device(&cdev->dev);
754 return ret;
757 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
759 struct ccw_device *cdev;
760 int ret;
762 cdev = io_subchannel_allocate_dev(sch);
763 if (!IS_ERR(cdev)) {
764 ret = io_subchannel_initialize_dev(sch, cdev);
765 if (ret)
766 cdev = ERR_PTR(ret);
768 return cdev;
771 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
773 static void sch_create_and_recog_new_device(struct subchannel *sch)
775 struct ccw_device *cdev;
777 /* Need to allocate a new ccw device. */
778 cdev = io_subchannel_create_ccwdev(sch);
779 if (IS_ERR(cdev)) {
780 /* OK, we did everything we could... */
781 css_sch_device_unregister(sch);
782 return;
784 /* Start recognition for the new ccw device. */
785 io_subchannel_recog(cdev, sch);
789 * Register recognized device.
791 static void io_subchannel_register(struct ccw_device *cdev)
793 struct subchannel *sch;
794 int ret, adjust_init_count = 1;
795 unsigned long flags;
797 sch = to_subchannel(cdev->dev.parent);
799 * Check if subchannel is still registered. It may have become
800 * unregistered if a machine check hit us after finishing
801 * device recognition but before the register work could be
802 * queued.
804 if (!device_is_registered(&sch->dev))
805 goto out_err;
806 css_update_ssd_info(sch);
808 * io_subchannel_register() will also be called after device
809 * recognition has been done for a boxed device (which will already
810 * be registered). We need to reprobe since we may now have sense id
811 * information.
813 if (device_is_registered(&cdev->dev)) {
814 if (!cdev->drv) {
815 ret = device_reprobe(&cdev->dev);
816 if (ret)
817 /* We can't do much here. */
818 CIO_MSG_EVENT(0, "device_reprobe() returned"
819 " %d for 0.%x.%04x\n", ret,
820 cdev->private->dev_id.ssid,
821 cdev->private->dev_id.devno);
823 adjust_init_count = 0;
824 goto out;
827 * Now we know this subchannel will stay, we can throw
828 * our delayed uevent.
830 dev_set_uevent_suppress(&sch->dev, 0);
831 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
832 /* make it known to the system */
833 ret = ccw_device_add(cdev);
834 if (ret) {
835 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
836 cdev->private->dev_id.ssid,
837 cdev->private->dev_id.devno, ret);
838 spin_lock_irqsave(sch->lock, flags);
839 sch_set_cdev(sch, NULL);
840 spin_unlock_irqrestore(sch->lock, flags);
841 /* Release initial device reference. */
842 put_device(&cdev->dev);
843 goto out_err;
845 out:
846 cdev->private->flags.recog_done = 1;
847 wake_up(&cdev->private->wait_q);
848 out_err:
849 if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
850 wake_up(&ccw_device_init_wq);
853 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
855 struct subchannel *sch;
857 /* Get subchannel reference for local processing. */
858 if (!get_device(cdev->dev.parent))
859 return;
860 sch = to_subchannel(cdev->dev.parent);
861 css_sch_device_unregister(sch);
862 /* Release subchannel reference for local processing. */
863 put_device(&sch->dev);
867 * subchannel recognition done. Called from the state machine.
869 void
870 io_subchannel_recog_done(struct ccw_device *cdev)
872 if (css_init_done == 0) {
873 cdev->private->flags.recog_done = 1;
874 return;
876 switch (cdev->private->state) {
877 case DEV_STATE_BOXED:
878 /* Device did not respond in time. */
879 case DEV_STATE_NOT_OPER:
880 cdev->private->flags.recog_done = 1;
881 /* Remove device found not operational. */
882 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
883 if (atomic_dec_and_test(&ccw_device_init_count))
884 wake_up(&ccw_device_init_wq);
885 break;
886 case DEV_STATE_OFFLINE:
888 * We can't register the device in interrupt context so
889 * we schedule a work item.
891 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
892 break;
896 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
898 /* Increase counter of devices currently in recognition. */
899 atomic_inc(&ccw_device_init_count);
901 /* Start async. device sensing. */
902 spin_lock_irq(sch->lock);
903 ccw_device_recognition(cdev);
904 spin_unlock_irq(sch->lock);
907 static int ccw_device_move_to_sch(struct ccw_device *cdev,
908 struct subchannel *sch)
910 struct subchannel *old_sch;
911 int rc, old_enabled = 0;
913 old_sch = to_subchannel(cdev->dev.parent);
914 /* Obtain child reference for new parent. */
915 if (!get_device(&sch->dev))
916 return -ENODEV;
918 if (!sch_is_pseudo_sch(old_sch)) {
919 spin_lock_irq(old_sch->lock);
920 old_enabled = old_sch->schib.pmcw.ena;
921 rc = 0;
922 if (old_enabled)
923 rc = cio_disable_subchannel(old_sch);
924 spin_unlock_irq(old_sch->lock);
925 if (rc == -EBUSY) {
926 /* Release child reference for new parent. */
927 put_device(&sch->dev);
928 return rc;
932 mutex_lock(&sch->reg_mutex);
933 rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
934 mutex_unlock(&sch->reg_mutex);
935 if (rc) {
936 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
937 cdev->private->dev_id.ssid,
938 cdev->private->dev_id.devno, sch->schid.ssid,
939 sch->schib.pmcw.dev, rc);
940 if (old_enabled) {
941 /* Try to reenable the old subchannel. */
942 spin_lock_irq(old_sch->lock);
943 cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
944 spin_unlock_irq(old_sch->lock);
946 /* Release child reference for new parent. */
947 put_device(&sch->dev);
948 return rc;
950 /* Clean up old subchannel. */
951 if (!sch_is_pseudo_sch(old_sch)) {
952 spin_lock_irq(old_sch->lock);
953 sch_set_cdev(old_sch, NULL);
954 spin_unlock_irq(old_sch->lock);
955 css_schedule_eval(old_sch->schid);
957 /* Release child reference for old parent. */
958 put_device(&old_sch->dev);
959 /* Initialize new subchannel. */
960 spin_lock_irq(sch->lock);
961 cdev->ccwlock = sch->lock;
962 if (!sch_is_pseudo_sch(sch))
963 sch_set_cdev(sch, cdev);
964 spin_unlock_irq(sch->lock);
965 if (!sch_is_pseudo_sch(sch))
966 css_update_ssd_info(sch);
967 return 0;
970 static int ccw_device_move_to_orph(struct ccw_device *cdev)
972 struct subchannel *sch = to_subchannel(cdev->dev.parent);
973 struct channel_subsystem *css = to_css(sch->dev.parent);
975 return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
978 static void io_subchannel_irq(struct subchannel *sch)
980 struct ccw_device *cdev;
982 cdev = sch_get_cdev(sch);
984 CIO_TRACE_EVENT(6, "IRQ");
985 CIO_TRACE_EVENT(6, dev_name(&sch->dev));
986 if (cdev)
987 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
988 else
989 inc_irq_stat(IRQIO_CIO);
992 void io_subchannel_init_config(struct subchannel *sch)
994 memset(&sch->config, 0, sizeof(sch->config));
995 sch->config.csense = 1;
998 static void io_subchannel_init_fields(struct subchannel *sch)
1000 if (cio_is_console(sch->schid))
1001 sch->opm = 0xff;
1002 else
1003 sch->opm = chp_get_sch_opm(sch);
1004 sch->lpm = sch->schib.pmcw.pam & sch->opm;
1005 sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
1007 CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
1008 " - PIM = %02X, PAM = %02X, POM = %02X\n",
1009 sch->schib.pmcw.dev, sch->schid.ssid,
1010 sch->schid.sch_no, sch->schib.pmcw.pim,
1011 sch->schib.pmcw.pam, sch->schib.pmcw.pom);
1013 io_subchannel_init_config(sch);
1017 * Note: We always return 0 so that we bind to the device even on error.
1018 * This is needed so that our remove function is called on unregister.
1020 static int io_subchannel_probe(struct subchannel *sch)
1022 struct io_subchannel_private *io_priv;
1023 struct ccw_device *cdev;
1024 int rc;
1026 if (cio_is_console(sch->schid)) {
1027 rc = sysfs_create_group(&sch->dev.kobj,
1028 &io_subchannel_attr_group);
1029 if (rc)
1030 CIO_MSG_EVENT(0, "Failed to create io subchannel "
1031 "attributes for subchannel "
1032 "0.%x.%04x (rc=%d)\n",
1033 sch->schid.ssid, sch->schid.sch_no, rc);
1035 * The console subchannel already has an associated ccw_device.
1036 * Throw the delayed uevent for the subchannel, register
1037 * the ccw_device and exit.
1039 dev_set_uevent_suppress(&sch->dev, 0);
1040 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1041 cdev = sch_get_cdev(sch);
1042 rc = ccw_device_add(cdev);
1043 if (rc) {
1044 /* Release online reference. */
1045 put_device(&cdev->dev);
1046 goto out_schedule;
1048 if (atomic_dec_and_test(&ccw_device_init_count))
1049 wake_up(&ccw_device_init_wq);
1050 return 0;
1052 io_subchannel_init_fields(sch);
1053 rc = cio_commit_config(sch);
1054 if (rc)
1055 goto out_schedule;
1056 rc = sysfs_create_group(&sch->dev.kobj,
1057 &io_subchannel_attr_group);
1058 if (rc)
1059 goto out_schedule;
1060 /* Allocate I/O subchannel private data. */
1061 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1062 if (!io_priv)
1063 goto out_schedule;
1065 set_io_private(sch, io_priv);
1066 css_schedule_eval(sch->schid);
1067 return 0;
1069 out_schedule:
1070 spin_lock_irq(sch->lock);
1071 css_sched_sch_todo(sch, SCH_TODO_UNREG);
1072 spin_unlock_irq(sch->lock);
1073 return 0;
1076 static int
1077 io_subchannel_remove (struct subchannel *sch)
1079 struct io_subchannel_private *io_priv = to_io_private(sch);
1080 struct ccw_device *cdev;
1082 cdev = sch_get_cdev(sch);
1083 if (!cdev)
1084 goto out_free;
1085 io_subchannel_quiesce(sch);
1086 /* Set ccw device to not operational and drop reference. */
1087 spin_lock_irq(cdev->ccwlock);
1088 sch_set_cdev(sch, NULL);
1089 set_io_private(sch, NULL);
1090 cdev->private->state = DEV_STATE_NOT_OPER;
1091 spin_unlock_irq(cdev->ccwlock);
1092 ccw_device_unregister(cdev);
1093 out_free:
1094 kfree(io_priv);
1095 sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1096 return 0;
1099 static void io_subchannel_verify(struct subchannel *sch)
1101 struct ccw_device *cdev;
1103 cdev = sch_get_cdev(sch);
1104 if (cdev)
1105 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1108 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1110 struct ccw_device *cdev;
1112 cdev = sch_get_cdev(sch);
1113 if (!cdev)
1114 return;
1115 if (cio_update_schib(sch))
1116 goto err;
1117 /* Check for I/O on path. */
1118 if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1119 goto out;
1120 if (cdev->private->state == DEV_STATE_ONLINE) {
1121 ccw_device_kill_io(cdev);
1122 goto out;
1124 if (cio_clear(sch))
1125 goto err;
1126 out:
1127 /* Trigger path verification. */
1128 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1129 return;
1131 err:
1132 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1135 static int io_subchannel_chp_event(struct subchannel *sch,
1136 struct chp_link *link, int event)
1138 struct ccw_device *cdev = sch_get_cdev(sch);
1139 int mask;
1141 mask = chp_ssd_get_mask(&sch->ssd_info, link);
1142 if (!mask)
1143 return 0;
1144 switch (event) {
1145 case CHP_VARY_OFF:
1146 sch->opm &= ~mask;
1147 sch->lpm &= ~mask;
1148 if (cdev)
1149 cdev->private->path_gone_mask |= mask;
1150 io_subchannel_terminate_path(sch, mask);
1151 break;
1152 case CHP_VARY_ON:
1153 sch->opm |= mask;
1154 sch->lpm |= mask;
1155 if (cdev)
1156 cdev->private->path_new_mask |= mask;
1157 io_subchannel_verify(sch);
1158 break;
1159 case CHP_OFFLINE:
1160 if (cio_update_schib(sch))
1161 return -ENODEV;
1162 if (cdev)
1163 cdev->private->path_gone_mask |= mask;
1164 io_subchannel_terminate_path(sch, mask);
1165 break;
1166 case CHP_ONLINE:
1167 if (cio_update_schib(sch))
1168 return -ENODEV;
1169 sch->lpm |= mask & sch->opm;
1170 if (cdev)
1171 cdev->private->path_new_mask |= mask;
1172 io_subchannel_verify(sch);
1173 break;
1175 return 0;
1178 static void io_subchannel_quiesce(struct subchannel *sch)
1180 struct ccw_device *cdev;
1181 int ret;
1183 spin_lock_irq(sch->lock);
1184 cdev = sch_get_cdev(sch);
1185 if (cio_is_console(sch->schid))
1186 goto out_unlock;
1187 if (!sch->schib.pmcw.ena)
1188 goto out_unlock;
1189 ret = cio_disable_subchannel(sch);
1190 if (ret != -EBUSY)
1191 goto out_unlock;
1192 if (cdev->handler)
1193 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1194 while (ret == -EBUSY) {
1195 cdev->private->state = DEV_STATE_QUIESCE;
1196 cdev->private->iretry = 255;
1197 ret = ccw_device_cancel_halt_clear(cdev);
1198 if (ret == -EBUSY) {
1199 ccw_device_set_timeout(cdev, HZ/10);
1200 spin_unlock_irq(sch->lock);
1201 wait_event(cdev->private->wait_q,
1202 cdev->private->state != DEV_STATE_QUIESCE);
1203 spin_lock_irq(sch->lock);
1205 ret = cio_disable_subchannel(sch);
1207 out_unlock:
1208 spin_unlock_irq(sch->lock);
1211 static void io_subchannel_shutdown(struct subchannel *sch)
1213 io_subchannel_quiesce(sch);
1216 static int device_is_disconnected(struct ccw_device *cdev)
1218 if (!cdev)
1219 return 0;
1220 return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1221 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1224 static int recovery_check(struct device *dev, void *data)
1226 struct ccw_device *cdev = to_ccwdev(dev);
1227 struct subchannel *sch;
1228 int *redo = data;
1230 spin_lock_irq(cdev->ccwlock);
1231 switch (cdev->private->state) {
1232 case DEV_STATE_ONLINE:
1233 sch = to_subchannel(cdev->dev.parent);
1234 if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)
1235 break;
1236 /* fall through */
1237 case DEV_STATE_DISCONNECTED:
1238 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1239 cdev->private->dev_id.ssid,
1240 cdev->private->dev_id.devno);
1241 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1242 *redo = 1;
1243 break;
1244 case DEV_STATE_DISCONNECTED_SENSE_ID:
1245 *redo = 1;
1246 break;
1248 spin_unlock_irq(cdev->ccwlock);
1250 return 0;
1253 static void recovery_work_func(struct work_struct *unused)
1255 int redo = 0;
1257 bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1258 if (redo) {
1259 spin_lock_irq(&recovery_lock);
1260 if (!timer_pending(&recovery_timer)) {
1261 if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1262 recovery_phase++;
1263 mod_timer(&recovery_timer, jiffies +
1264 recovery_delay[recovery_phase] * HZ);
1266 spin_unlock_irq(&recovery_lock);
1267 } else
1268 CIO_MSG_EVENT(3, "recovery: end\n");
1271 static DECLARE_WORK(recovery_work, recovery_work_func);
1273 static void recovery_func(struct timer_list *unused)
1276 * We can't do our recovery in softirq context and it's not
1277 * performance critical, so we schedule it.
1279 schedule_work(&recovery_work);
1282 void ccw_device_schedule_recovery(void)
1284 unsigned long flags;
1286 CIO_MSG_EVENT(3, "recovery: schedule\n");
1287 spin_lock_irqsave(&recovery_lock, flags);
1288 if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1289 recovery_phase = 0;
1290 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1292 spin_unlock_irqrestore(&recovery_lock, flags);
1295 static int purge_fn(struct device *dev, void *data)
1297 struct ccw_device *cdev = to_ccwdev(dev);
1298 struct ccw_dev_id *id = &cdev->private->dev_id;
1300 spin_lock_irq(cdev->ccwlock);
1301 if (is_blacklisted(id->ssid, id->devno) &&
1302 (cdev->private->state == DEV_STATE_OFFLINE) &&
1303 (atomic_cmpxchg(&cdev->private->onoff, 0, 1) == 0)) {
1304 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1305 id->devno);
1306 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1307 atomic_set(&cdev->private->onoff, 0);
1309 spin_unlock_irq(cdev->ccwlock);
1310 /* Abort loop in case of pending signal. */
1311 if (signal_pending(current))
1312 return -EINTR;
1314 return 0;
1318 * ccw_purge_blacklisted - purge unused, blacklisted devices
1320 * Unregister all ccw devices that are offline and on the blacklist.
1322 int ccw_purge_blacklisted(void)
1324 CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1325 bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1326 return 0;
1329 void ccw_device_set_disconnected(struct ccw_device *cdev)
1331 if (!cdev)
1332 return;
1333 ccw_device_set_timeout(cdev, 0);
1334 cdev->private->flags.fake_irb = 0;
1335 cdev->private->state = DEV_STATE_DISCONNECTED;
1336 if (cdev->online)
1337 ccw_device_schedule_recovery();
1340 void ccw_device_set_notoper(struct ccw_device *cdev)
1342 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1344 CIO_TRACE_EVENT(2, "notoper");
1345 CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1346 ccw_device_set_timeout(cdev, 0);
1347 cio_disable_subchannel(sch);
1348 cdev->private->state = DEV_STATE_NOT_OPER;
1351 enum io_sch_action {
1352 IO_SCH_UNREG,
1353 IO_SCH_ORPH_UNREG,
1354 IO_SCH_ATTACH,
1355 IO_SCH_UNREG_ATTACH,
1356 IO_SCH_ORPH_ATTACH,
1357 IO_SCH_REPROBE,
1358 IO_SCH_VERIFY,
1359 IO_SCH_DISC,
1360 IO_SCH_NOP,
1363 static enum io_sch_action sch_get_action(struct subchannel *sch)
1365 struct ccw_device *cdev;
1367 cdev = sch_get_cdev(sch);
1368 if (cio_update_schib(sch)) {
1369 /* Not operational. */
1370 if (!cdev)
1371 return IO_SCH_UNREG;
1372 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1373 return IO_SCH_UNREG;
1374 return IO_SCH_ORPH_UNREG;
1376 /* Operational. */
1377 if (!cdev)
1378 return IO_SCH_ATTACH;
1379 if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1380 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1381 return IO_SCH_UNREG_ATTACH;
1382 return IO_SCH_ORPH_ATTACH;
1384 if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1385 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1386 return IO_SCH_UNREG;
1387 return IO_SCH_DISC;
1389 if (device_is_disconnected(cdev))
1390 return IO_SCH_REPROBE;
1391 if (cdev->online && !cdev->private->flags.resuming)
1392 return IO_SCH_VERIFY;
1393 if (cdev->private->state == DEV_STATE_NOT_OPER)
1394 return IO_SCH_UNREG_ATTACH;
1395 return IO_SCH_NOP;
1399 * io_subchannel_sch_event - process subchannel event
1400 * @sch: subchannel
1401 * @process: non-zero if function is called in process context
1403 * An unspecified event occurred for this subchannel. Adjust data according
1404 * to the current operational state of the subchannel and device. Return
1405 * zero when the event has been handled sufficiently or -EAGAIN when this
1406 * function should be called again in process context.
1408 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1410 unsigned long flags;
1411 struct ccw_device *cdev;
1412 struct ccw_dev_id dev_id;
1413 enum io_sch_action action;
1414 int rc = -EAGAIN;
1416 spin_lock_irqsave(sch->lock, flags);
1417 if (!device_is_registered(&sch->dev))
1418 goto out_unlock;
1419 if (work_pending(&sch->todo_work))
1420 goto out_unlock;
1421 cdev = sch_get_cdev(sch);
1422 if (cdev && work_pending(&cdev->private->todo_work))
1423 goto out_unlock;
1424 action = sch_get_action(sch);
1425 CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1426 sch->schid.ssid, sch->schid.sch_no, process,
1427 action);
1428 /* Perform immediate actions while holding the lock. */
1429 switch (action) {
1430 case IO_SCH_REPROBE:
1431 /* Trigger device recognition. */
1432 ccw_device_trigger_reprobe(cdev);
1433 rc = 0;
1434 goto out_unlock;
1435 case IO_SCH_VERIFY:
1436 /* Trigger path verification. */
1437 io_subchannel_verify(sch);
1438 rc = 0;
1439 goto out_unlock;
1440 case IO_SCH_DISC:
1441 ccw_device_set_disconnected(cdev);
1442 rc = 0;
1443 goto out_unlock;
1444 case IO_SCH_ORPH_UNREG:
1445 case IO_SCH_ORPH_ATTACH:
1446 ccw_device_set_disconnected(cdev);
1447 break;
1448 case IO_SCH_UNREG_ATTACH:
1449 case IO_SCH_UNREG:
1450 if (!cdev)
1451 break;
1452 if (cdev->private->state == DEV_STATE_SENSE_ID) {
1454 * Note: delayed work triggered by this event
1455 * and repeated calls to sch_event are synchronized
1456 * by the above check for work_pending(cdev).
1458 dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1459 } else
1460 ccw_device_set_notoper(cdev);
1461 break;
1462 case IO_SCH_NOP:
1463 rc = 0;
1464 goto out_unlock;
1465 default:
1466 break;
1468 spin_unlock_irqrestore(sch->lock, flags);
1469 /* All other actions require process context. */
1470 if (!process)
1471 goto out;
1472 /* Handle attached ccw device. */
1473 switch (action) {
1474 case IO_SCH_ORPH_UNREG:
1475 case IO_SCH_ORPH_ATTACH:
1476 /* Move ccw device to orphanage. */
1477 rc = ccw_device_move_to_orph(cdev);
1478 if (rc)
1479 goto out;
1480 break;
1481 case IO_SCH_UNREG_ATTACH:
1482 spin_lock_irqsave(sch->lock, flags);
1483 if (cdev->private->flags.resuming) {
1484 /* Device will be handled later. */
1485 rc = 0;
1486 goto out_unlock;
1488 sch_set_cdev(sch, NULL);
1489 spin_unlock_irqrestore(sch->lock, flags);
1490 /* Unregister ccw device. */
1491 ccw_device_unregister(cdev);
1492 break;
1493 default:
1494 break;
1496 /* Handle subchannel. */
1497 switch (action) {
1498 case IO_SCH_ORPH_UNREG:
1499 case IO_SCH_UNREG:
1500 if (!cdev || !cdev->private->flags.resuming)
1501 css_sch_device_unregister(sch);
1502 break;
1503 case IO_SCH_ORPH_ATTACH:
1504 case IO_SCH_UNREG_ATTACH:
1505 case IO_SCH_ATTACH:
1506 dev_id.ssid = sch->schid.ssid;
1507 dev_id.devno = sch->schib.pmcw.dev;
1508 cdev = get_ccwdev_by_dev_id(&dev_id);
1509 if (!cdev) {
1510 sch_create_and_recog_new_device(sch);
1511 break;
1513 rc = ccw_device_move_to_sch(cdev, sch);
1514 if (rc) {
1515 /* Release reference from get_ccwdev_by_dev_id() */
1516 put_device(&cdev->dev);
1517 goto out;
1519 spin_lock_irqsave(sch->lock, flags);
1520 ccw_device_trigger_reprobe(cdev);
1521 spin_unlock_irqrestore(sch->lock, flags);
1522 /* Release reference from get_ccwdev_by_dev_id() */
1523 put_device(&cdev->dev);
1524 break;
1525 default:
1526 break;
1528 return 0;
1530 out_unlock:
1531 spin_unlock_irqrestore(sch->lock, flags);
1532 out:
1533 return rc;
1536 static void ccw_device_set_int_class(struct ccw_device *cdev)
1538 struct ccw_driver *cdrv = cdev->drv;
1540 /* Note: we interpret class 0 in this context as an uninitialized
1541 * field since it translates to a non-I/O interrupt class. */
1542 if (cdrv->int_class != 0)
1543 cdev->private->int_class = cdrv->int_class;
1544 else
1545 cdev->private->int_class = IRQIO_CIO;
1548 #ifdef CONFIG_CCW_CONSOLE
1549 int __init ccw_device_enable_console(struct ccw_device *cdev)
1551 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1552 int rc;
1554 if (!cdev->drv || !cdev->handler)
1555 return -EINVAL;
1557 io_subchannel_init_fields(sch);
1558 rc = cio_commit_config(sch);
1559 if (rc)
1560 return rc;
1561 sch->driver = &io_subchannel_driver;
1562 io_subchannel_recog(cdev, sch);
1563 /* Now wait for the async. recognition to come to an end. */
1564 spin_lock_irq(cdev->ccwlock);
1565 while (!dev_fsm_final_state(cdev))
1566 ccw_device_wait_idle(cdev);
1568 /* Hold on to an extra reference while device is online. */
1569 get_device(&cdev->dev);
1570 rc = ccw_device_online(cdev);
1571 if (rc)
1572 goto out_unlock;
1574 while (!dev_fsm_final_state(cdev))
1575 ccw_device_wait_idle(cdev);
1577 if (cdev->private->state == DEV_STATE_ONLINE)
1578 cdev->online = 1;
1579 else
1580 rc = -EIO;
1581 out_unlock:
1582 spin_unlock_irq(cdev->ccwlock);
1583 if (rc) /* Give up online reference since onlining failed. */
1584 put_device(&cdev->dev);
1585 return rc;
1588 struct ccw_device * __init ccw_device_create_console(struct ccw_driver *drv)
1590 struct io_subchannel_private *io_priv;
1591 struct ccw_device *cdev;
1592 struct subchannel *sch;
1594 sch = cio_probe_console();
1595 if (IS_ERR(sch))
1596 return ERR_CAST(sch);
1598 io_priv = kzalloc(sizeof(*io_priv), GFP_KERNEL | GFP_DMA);
1599 if (!io_priv) {
1600 put_device(&sch->dev);
1601 return ERR_PTR(-ENOMEM);
1603 set_io_private(sch, io_priv);
1604 cdev = io_subchannel_create_ccwdev(sch);
1605 if (IS_ERR(cdev)) {
1606 put_device(&sch->dev);
1607 kfree(io_priv);
1608 return cdev;
1610 cdev->drv = drv;
1611 ccw_device_set_int_class(cdev);
1612 return cdev;
1615 void __init ccw_device_destroy_console(struct ccw_device *cdev)
1617 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1618 struct io_subchannel_private *io_priv = to_io_private(sch);
1620 set_io_private(sch, NULL);
1621 put_device(&sch->dev);
1622 put_device(&cdev->dev);
1623 kfree(io_priv);
1627 * ccw_device_wait_idle() - busy wait for device to become idle
1628 * @cdev: ccw device
1630 * Poll until activity control is zero, that is, no function or data
1631 * transfer is pending/active.
1632 * Called with device lock being held.
1634 void ccw_device_wait_idle(struct ccw_device *cdev)
1636 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1638 while (1) {
1639 cio_tsch(sch);
1640 if (sch->schib.scsw.cmd.actl == 0)
1641 break;
1642 udelay_simple(100);
1646 static int ccw_device_pm_restore(struct device *dev);
1648 int ccw_device_force_console(struct ccw_device *cdev)
1650 return ccw_device_pm_restore(&cdev->dev);
1652 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1653 #endif
1656 * get ccw_device matching the busid, but only if owned by cdrv
1658 static int
1659 __ccwdev_check_busid(struct device *dev, void *id)
1661 char *bus_id;
1663 bus_id = id;
1665 return (strcmp(bus_id, dev_name(dev)) == 0);
1670 * get_ccwdev_by_busid() - obtain device from a bus id
1671 * @cdrv: driver the device is owned by
1672 * @bus_id: bus id of the device to be searched
1674 * This function searches all devices owned by @cdrv for a device with a bus
1675 * id matching @bus_id.
1676 * Returns:
1677 * If a match is found, its reference count of the found device is increased
1678 * and it is returned; else %NULL is returned.
1680 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1681 const char *bus_id)
1683 struct device *dev;
1685 dev = driver_find_device(&cdrv->driver, NULL, (void *)bus_id,
1686 __ccwdev_check_busid);
1688 return dev ? to_ccwdev(dev) : NULL;
1691 /************************** device driver handling ************************/
1693 /* This is the implementation of the ccw_driver class. The probe, remove
1694 * and release methods are initially very similar to the device_driver
1695 * implementations, with the difference that they have ccw_device
1696 * arguments.
1698 * A ccw driver also contains the information that is needed for
1699 * device matching.
1701 static int
1702 ccw_device_probe (struct device *dev)
1704 struct ccw_device *cdev = to_ccwdev(dev);
1705 struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1706 int ret;
1708 cdev->drv = cdrv; /* to let the driver call _set_online */
1709 ccw_device_set_int_class(cdev);
1710 ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1711 if (ret) {
1712 cdev->drv = NULL;
1713 cdev->private->int_class = IRQIO_CIO;
1714 return ret;
1717 return 0;
1720 static int ccw_device_remove(struct device *dev)
1722 struct ccw_device *cdev = to_ccwdev(dev);
1723 struct ccw_driver *cdrv = cdev->drv;
1724 int ret;
1726 if (cdrv->remove)
1727 cdrv->remove(cdev);
1729 spin_lock_irq(cdev->ccwlock);
1730 if (cdev->online) {
1731 cdev->online = 0;
1732 ret = ccw_device_offline(cdev);
1733 spin_unlock_irq(cdev->ccwlock);
1734 if (ret == 0)
1735 wait_event(cdev->private->wait_q,
1736 dev_fsm_final_state(cdev));
1737 else
1738 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1739 "device 0.%x.%04x\n",
1740 ret, cdev->private->dev_id.ssid,
1741 cdev->private->dev_id.devno);
1742 /* Give up reference obtained in ccw_device_set_online(). */
1743 put_device(&cdev->dev);
1744 spin_lock_irq(cdev->ccwlock);
1746 ccw_device_set_timeout(cdev, 0);
1747 cdev->drv = NULL;
1748 cdev->private->int_class = IRQIO_CIO;
1749 spin_unlock_irq(cdev->ccwlock);
1750 __disable_cmf(cdev);
1752 return 0;
1755 static void ccw_device_shutdown(struct device *dev)
1757 struct ccw_device *cdev;
1759 cdev = to_ccwdev(dev);
1760 if (cdev->drv && cdev->drv->shutdown)
1761 cdev->drv->shutdown(cdev);
1762 __disable_cmf(cdev);
1765 static int ccw_device_pm_prepare(struct device *dev)
1767 struct ccw_device *cdev = to_ccwdev(dev);
1769 if (work_pending(&cdev->private->todo_work))
1770 return -EAGAIN;
1771 /* Fail while device is being set online/offline. */
1772 if (atomic_read(&cdev->private->onoff))
1773 return -EAGAIN;
1775 if (cdev->online && cdev->drv && cdev->drv->prepare)
1776 return cdev->drv->prepare(cdev);
1778 return 0;
1781 static void ccw_device_pm_complete(struct device *dev)
1783 struct ccw_device *cdev = to_ccwdev(dev);
1785 if (cdev->online && cdev->drv && cdev->drv->complete)
1786 cdev->drv->complete(cdev);
1789 static int ccw_device_pm_freeze(struct device *dev)
1791 struct ccw_device *cdev = to_ccwdev(dev);
1792 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1793 int ret, cm_enabled;
1795 /* Fail suspend while device is in transistional state. */
1796 if (!dev_fsm_final_state(cdev))
1797 return -EAGAIN;
1798 if (!cdev->online)
1799 return 0;
1800 if (cdev->drv && cdev->drv->freeze) {
1801 ret = cdev->drv->freeze(cdev);
1802 if (ret)
1803 return ret;
1806 spin_lock_irq(sch->lock);
1807 cm_enabled = cdev->private->cmb != NULL;
1808 spin_unlock_irq(sch->lock);
1809 if (cm_enabled) {
1810 /* Don't have the css write on memory. */
1811 ret = ccw_set_cmf(cdev, 0);
1812 if (ret)
1813 return ret;
1815 /* From here on, disallow device driver I/O. */
1816 spin_lock_irq(sch->lock);
1817 ret = cio_disable_subchannel(sch);
1818 spin_unlock_irq(sch->lock);
1820 return ret;
1823 static int ccw_device_pm_thaw(struct device *dev)
1825 struct ccw_device *cdev = to_ccwdev(dev);
1826 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1827 int ret, cm_enabled;
1829 if (!cdev->online)
1830 return 0;
1832 spin_lock_irq(sch->lock);
1833 /* Allow device driver I/O again. */
1834 ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1835 cm_enabled = cdev->private->cmb != NULL;
1836 spin_unlock_irq(sch->lock);
1837 if (ret)
1838 return ret;
1840 if (cm_enabled) {
1841 ret = ccw_set_cmf(cdev, 1);
1842 if (ret)
1843 return ret;
1846 if (cdev->drv && cdev->drv->thaw)
1847 ret = cdev->drv->thaw(cdev);
1849 return ret;
1852 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1854 struct subchannel *sch = to_subchannel(cdev->dev.parent);
1856 spin_lock_irq(sch->lock);
1857 if (cio_is_console(sch->schid)) {
1858 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1859 goto out_unlock;
1862 * While we were sleeping, devices may have gone or become
1863 * available again. Kick re-detection.
1865 cdev->private->flags.resuming = 1;
1866 cdev->private->path_new_mask = LPM_ANYPATH;
1867 css_sched_sch_todo(sch, SCH_TODO_EVAL);
1868 spin_unlock_irq(sch->lock);
1869 css_wait_for_slow_path();
1871 /* cdev may have been moved to a different subchannel. */
1872 sch = to_subchannel(cdev->dev.parent);
1873 spin_lock_irq(sch->lock);
1874 if (cdev->private->state != DEV_STATE_ONLINE &&
1875 cdev->private->state != DEV_STATE_OFFLINE)
1876 goto out_unlock;
1878 ccw_device_recognition(cdev);
1879 spin_unlock_irq(sch->lock);
1880 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1881 cdev->private->state == DEV_STATE_DISCONNECTED);
1882 spin_lock_irq(sch->lock);
1884 out_unlock:
1885 cdev->private->flags.resuming = 0;
1886 spin_unlock_irq(sch->lock);
1889 static int resume_handle_boxed(struct ccw_device *cdev)
1891 cdev->private->state = DEV_STATE_BOXED;
1892 if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1893 return 0;
1894 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1895 return -ENODEV;
1898 static int resume_handle_disc(struct ccw_device *cdev)
1900 cdev->private->state = DEV_STATE_DISCONNECTED;
1901 if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1902 return 0;
1903 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1904 return -ENODEV;
1907 static int ccw_device_pm_restore(struct device *dev)
1909 struct ccw_device *cdev = to_ccwdev(dev);
1910 struct subchannel *sch;
1911 int ret = 0;
1913 __ccw_device_pm_restore(cdev);
1914 sch = to_subchannel(cdev->dev.parent);
1915 spin_lock_irq(sch->lock);
1916 if (cio_is_console(sch->schid))
1917 goto out_restore;
1919 /* check recognition results */
1920 switch (cdev->private->state) {
1921 case DEV_STATE_OFFLINE:
1922 case DEV_STATE_ONLINE:
1923 cdev->private->flags.donotify = 0;
1924 break;
1925 case DEV_STATE_BOXED:
1926 ret = resume_handle_boxed(cdev);
1927 if (ret)
1928 goto out_unlock;
1929 goto out_restore;
1930 default:
1931 ret = resume_handle_disc(cdev);
1932 if (ret)
1933 goto out_unlock;
1934 goto out_restore;
1936 /* check if the device type has changed */
1937 if (!ccw_device_test_sense_data(cdev)) {
1938 ccw_device_update_sense_data(cdev);
1939 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1940 ret = -ENODEV;
1941 goto out_unlock;
1943 if (!cdev->online)
1944 goto out_unlock;
1946 if (ccw_device_online(cdev)) {
1947 ret = resume_handle_disc(cdev);
1948 if (ret)
1949 goto out_unlock;
1950 goto out_restore;
1952 spin_unlock_irq(sch->lock);
1953 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1954 spin_lock_irq(sch->lock);
1956 if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1957 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1958 ret = -ENODEV;
1959 goto out_unlock;
1962 /* reenable cmf, if needed */
1963 if (cdev->private->cmb) {
1964 spin_unlock_irq(sch->lock);
1965 ret = ccw_set_cmf(cdev, 1);
1966 spin_lock_irq(sch->lock);
1967 if (ret) {
1968 CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1969 "(rc=%d)\n", cdev->private->dev_id.ssid,
1970 cdev->private->dev_id.devno, ret);
1971 ret = 0;
1975 out_restore:
1976 spin_unlock_irq(sch->lock);
1977 if (cdev->online && cdev->drv && cdev->drv->restore)
1978 ret = cdev->drv->restore(cdev);
1979 return ret;
1981 out_unlock:
1982 spin_unlock_irq(sch->lock);
1983 return ret;
1986 static const struct dev_pm_ops ccw_pm_ops = {
1987 .prepare = ccw_device_pm_prepare,
1988 .complete = ccw_device_pm_complete,
1989 .freeze = ccw_device_pm_freeze,
1990 .thaw = ccw_device_pm_thaw,
1991 .restore = ccw_device_pm_restore,
1994 static struct bus_type ccw_bus_type = {
1995 .name = "ccw",
1996 .match = ccw_bus_match,
1997 .uevent = ccw_uevent,
1998 .probe = ccw_device_probe,
1999 .remove = ccw_device_remove,
2000 .shutdown = ccw_device_shutdown,
2001 .pm = &ccw_pm_ops,
2005 * ccw_driver_register() - register a ccw driver
2006 * @cdriver: driver to be registered
2008 * This function is mainly a wrapper around driver_register().
2009 * Returns:
2010 * %0 on success and a negative error value on failure.
2012 int ccw_driver_register(struct ccw_driver *cdriver)
2014 struct device_driver *drv = &cdriver->driver;
2016 drv->bus = &ccw_bus_type;
2018 return driver_register(drv);
2022 * ccw_driver_unregister() - deregister a ccw driver
2023 * @cdriver: driver to be deregistered
2025 * This function is mainly a wrapper around driver_unregister().
2027 void ccw_driver_unregister(struct ccw_driver *cdriver)
2029 driver_unregister(&cdriver->driver);
2032 static void ccw_device_todo(struct work_struct *work)
2034 struct ccw_device_private *priv;
2035 struct ccw_device *cdev;
2036 struct subchannel *sch;
2037 enum cdev_todo todo;
2039 priv = container_of(work, struct ccw_device_private, todo_work);
2040 cdev = priv->cdev;
2041 sch = to_subchannel(cdev->dev.parent);
2042 /* Find out todo. */
2043 spin_lock_irq(cdev->ccwlock);
2044 todo = priv->todo;
2045 priv->todo = CDEV_TODO_NOTHING;
2046 CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
2047 priv->dev_id.ssid, priv->dev_id.devno, todo);
2048 spin_unlock_irq(cdev->ccwlock);
2049 /* Perform todo. */
2050 switch (todo) {
2051 case CDEV_TODO_ENABLE_CMF:
2052 cmf_reenable(cdev);
2053 break;
2054 case CDEV_TODO_REBIND:
2055 ccw_device_do_unbind_bind(cdev);
2056 break;
2057 case CDEV_TODO_REGISTER:
2058 io_subchannel_register(cdev);
2059 break;
2060 case CDEV_TODO_UNREG_EVAL:
2061 if (!sch_is_pseudo_sch(sch))
2062 css_schedule_eval(sch->schid);
2063 /* fall-through */
2064 case CDEV_TODO_UNREG:
2065 if (sch_is_pseudo_sch(sch))
2066 ccw_device_unregister(cdev);
2067 else
2068 ccw_device_call_sch_unregister(cdev);
2069 break;
2070 default:
2071 break;
2073 /* Release workqueue ref. */
2074 put_device(&cdev->dev);
2078 * ccw_device_sched_todo - schedule ccw device operation
2079 * @cdev: ccw device
2080 * @todo: todo
2082 * Schedule the operation identified by @todo to be performed on the slow path
2083 * workqueue. Do nothing if another operation with higher priority is already
2084 * scheduled. Needs to be called with ccwdev lock held.
2086 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2088 CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2089 cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2090 todo);
2091 if (cdev->private->todo >= todo)
2092 return;
2093 cdev->private->todo = todo;
2094 /* Get workqueue ref. */
2095 if (!get_device(&cdev->dev))
2096 return;
2097 if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2098 /* Already queued, release workqueue ref. */
2099 put_device(&cdev->dev);
2104 * ccw_device_siosl() - initiate logging
2105 * @cdev: ccw device
2107 * This function is used to invoke model-dependent logging within the channel
2108 * subsystem.
2110 int ccw_device_siosl(struct ccw_device *cdev)
2112 struct subchannel *sch = to_subchannel(cdev->dev.parent);
2114 return chsc_siosl(sch->schid);
2116 EXPORT_SYMBOL_GPL(ccw_device_siosl);
2118 EXPORT_SYMBOL(ccw_device_set_online);
2119 EXPORT_SYMBOL(ccw_device_set_offline);
2120 EXPORT_SYMBOL(ccw_driver_register);
2121 EXPORT_SYMBOL(ccw_driver_unregister);
2122 EXPORT_SYMBOL(get_ccwdev_by_busid);