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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * drivers/base/core.c - core driver model code (device registration, etc)
4 *
5 * Copyright (c) 2002-3 Patrick Mochel
6 * Copyright (c) 2002-3 Open Source Development Labs
7 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
8 * Copyright (c) 2006 Novell, Inc.
9 */
10
11#include <linux/acpi.h>
12#include <linux/cpufreq.h>
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/fwnode.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/string.h>
20#include <linux/kdev_t.h>
21#include <linux/notifier.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/genhd.h>
25#include <linux/mutex.h>
26#include <linux/pm_runtime.h>
27#include <linux/netdevice.h>
28#include <linux/sched/signal.h>
29#include <linux/sysfs.h>
30
31#include "base.h"
32#include "power/power.h"
33
34#ifdef CONFIG_SYSFS_DEPRECATED
35#ifdef CONFIG_SYSFS_DEPRECATED_V2
36long sysfs_deprecated = 1;
37#else
38long sysfs_deprecated = 0;
39#endif
40static int __init sysfs_deprecated_setup(char *arg)
41{
42 return kstrtol(arg, 10, &sysfs_deprecated);
43}
44early_param("sysfs.deprecated", sysfs_deprecated_setup);
45#endif
46
47/* Device links support. */
48
49#ifdef CONFIG_SRCU
50static DEFINE_MUTEX(device_links_lock);
51DEFINE_STATIC_SRCU(device_links_srcu);
52
53static inline void device_links_write_lock(void)
54{
55 mutex_lock(&device_links_lock);
56}
57
58static inline void device_links_write_unlock(void)
59{
60 mutex_unlock(&device_links_lock);
61}
62
63int device_links_read_lock(void)
64{
65 return srcu_read_lock(&device_links_srcu);
66}
67
68void device_links_read_unlock(int idx)
69{
70 srcu_read_unlock(&device_links_srcu, idx);
71}
72
73int device_links_read_lock_held(void)
74{
75 return srcu_read_lock_held(&device_links_srcu);
76}
77#else /* !CONFIG_SRCU */
78static DECLARE_RWSEM(device_links_lock);
79
80static inline void device_links_write_lock(void)
81{
82 down_write(&device_links_lock);
83}
84
85static inline void device_links_write_unlock(void)
86{
87 up_write(&device_links_lock);
88}
89
90int device_links_read_lock(void)
91{
92 down_read(&device_links_lock);
93 return 0;
94}
95
96void device_links_read_unlock(int not_used)
97{
98 up_read(&device_links_lock);
99}
100
101#ifdef CONFIG_DEBUG_LOCK_ALLOC
102int device_links_read_lock_held(void)
103{
104 return lockdep_is_held(&device_links_lock);
105}
106#endif
107#endif /* !CONFIG_SRCU */
108
109/**
110 * device_is_dependent - Check if one device depends on another one
111 * @dev: Device to check dependencies for.
112 * @target: Device to check against.
113 *
114 * Check if @target depends on @dev or any device dependent on it (its child or
115 * its consumer etc). Return 1 if that is the case or 0 otherwise.
116 */
117static int device_is_dependent(struct device *dev, void *target)
118{
119 struct device_link *link;
120 int ret;
121
122 if (dev == target)
123 return 1;
124
125 ret = device_for_each_child(dev, target, device_is_dependent);
126 if (ret)
127 return ret;
128
129 list_for_each_entry(link, &dev->links.consumers, s_node) {
130 if (link->consumer == target)
131 return 1;
132
133 ret = device_is_dependent(link->consumer, target);
134 if (ret)
135 break;
136 }
137 return ret;
138}
139
140static void device_link_init_status(struct device_link *link,
141 struct device *consumer,
142 struct device *supplier)
143{
144 switch (supplier->links.status) {
145 case DL_DEV_PROBING:
146 switch (consumer->links.status) {
147 case DL_DEV_PROBING:
148 /*
149 * A consumer driver can create a link to a supplier
150 * that has not completed its probing yet as long as it
151 * knows that the supplier is already functional (for
152 * example, it has just acquired some resources from the
153 * supplier).
154 */
155 link->status = DL_STATE_CONSUMER_PROBE;
156 break;
157 default:
158 link->status = DL_STATE_DORMANT;
159 break;
160 }
161 break;
162 case DL_DEV_DRIVER_BOUND:
163 switch (consumer->links.status) {
164 case DL_DEV_PROBING:
165 link->status = DL_STATE_CONSUMER_PROBE;
166 break;
167 case DL_DEV_DRIVER_BOUND:
168 link->status = DL_STATE_ACTIVE;
169 break;
170 default:
171 link->status = DL_STATE_AVAILABLE;
172 break;
173 }
174 break;
175 case DL_DEV_UNBINDING:
176 link->status = DL_STATE_SUPPLIER_UNBIND;
177 break;
178 default:
179 link->status = DL_STATE_DORMANT;
180 break;
181 }
182}
183
184static int device_reorder_to_tail(struct device *dev, void *not_used)
185{
186 struct device_link *link;
187
188 /*
189 * Devices that have not been registered yet will be put to the ends
190 * of the lists during the registration, so skip them here.
191 */
192 if (device_is_registered(dev))
193 devices_kset_move_last(dev);
194
195 if (device_pm_initialized(dev))
196 device_pm_move_last(dev);
197
198 device_for_each_child(dev, NULL, device_reorder_to_tail);
199 list_for_each_entry(link, &dev->links.consumers, s_node)
200 device_reorder_to_tail(link->consumer, NULL);
201
202 return 0;
203}
204
205/**
206 * device_pm_move_to_tail - Move set of devices to the end of device lists
207 * @dev: Device to move
208 *
209 * This is a device_reorder_to_tail() wrapper taking the requisite locks.
210 *
211 * It moves the @dev along with all of its children and all of its consumers
212 * to the ends of the device_kset and dpm_list, recursively.
213 */
214void device_pm_move_to_tail(struct device *dev)
215{
216 int idx;
217
218 idx = device_links_read_lock();
219 device_pm_lock();
220 device_reorder_to_tail(dev, NULL);
221 device_pm_unlock();
222 device_links_read_unlock(idx);
223}
224
225#define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
226 DL_FLAG_AUTOREMOVE_SUPPLIER | \
227 DL_FLAG_AUTOPROBE_CONSUMER)
228
229#define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
230 DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
231
232/**
233 * device_link_add - Create a link between two devices.
234 * @consumer: Consumer end of the link.
235 * @supplier: Supplier end of the link.
236 * @flags: Link flags.
237 *
238 * The caller is responsible for the proper synchronization of the link creation
239 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
240 * runtime PM framework to take the link into account. Second, if the
241 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
242 * be forced into the active metastate and reference-counted upon the creation
243 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
244 * ignored.
245 *
246 * If DL_FLAG_STATELESS is set in @flags, the caller of this function is
247 * expected to release the link returned by it directly with the help of either
248 * device_link_del() or device_link_remove().
249 *
250 * If that flag is not set, however, the caller of this function is handing the
251 * management of the link over to the driver core entirely and its return value
252 * can only be used to check whether or not the link is present. In that case,
253 * the DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER device link
254 * flags can be used to indicate to the driver core when the link can be safely
255 * deleted. Namely, setting one of them in @flags indicates to the driver core
256 * that the link is not going to be used (by the given caller of this function)
257 * after unbinding the consumer or supplier driver, respectively, from its
258 * device, so the link can be deleted at that point. If none of them is set,
259 * the link will be maintained until one of the devices pointed to by it (either
260 * the consumer or the supplier) is unregistered.
261 *
262 * Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and
263 * DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent
264 * managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can
265 * be used to request the driver core to automaticall probe for a consmer
266 * driver after successfully binding a driver to the supplier device.
267 *
268 * The combination of DL_FLAG_STATELESS and one of DL_FLAG_AUTOREMOVE_CONSUMER,
269 * DL_FLAG_AUTOREMOVE_SUPPLIER, or DL_FLAG_AUTOPROBE_CONSUMER set in @flags at
270 * the same time is invalid and will cause NULL to be returned upfront.
271 * However, if a device link between the given @consumer and @supplier pair
272 * exists already when this function is called for them, the existing link will
273 * be returned regardless of its current type and status (the link's flags may
274 * be modified then). The caller of this function is then expected to treat
275 * the link as though it has just been created, so (in particular) if
276 * DL_FLAG_STATELESS was passed in @flags, the link needs to be released
277 * explicitly when not needed any more (as stated above).
278 *
279 * A side effect of the link creation is re-ordering of dpm_list and the
280 * devices_kset list by moving the consumer device and all devices depending
281 * on it to the ends of these lists (that does not happen to devices that have
282 * not been registered when this function is called).
283 *
284 * The supplier device is required to be registered when this function is called
285 * and NULL will be returned if that is not the case. The consumer device need
286 * not be registered, however.
287 */
288struct device_link *device_link_add(struct device *consumer,
289 struct device *supplier, u32 flags)
290{
291 struct device_link *link;
292
293 if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS ||
294 (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
295 (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
296 flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
297 DL_FLAG_AUTOREMOVE_SUPPLIER)))
298 return NULL;
299
300 if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
301 if (pm_runtime_get_sync(supplier) < 0) {
302 pm_runtime_put_noidle(supplier);
303 return NULL;
304 }
305 }
306
307 if (!(flags & DL_FLAG_STATELESS))
308 flags |= DL_FLAG_MANAGED;
309
310 device_links_write_lock();
311 device_pm_lock();
312
313 /*
314 * If the supplier has not been fully registered yet or there is a
315 * reverse dependency between the consumer and the supplier already in
316 * the graph, return NULL.
317 */
318 if (!device_pm_initialized(supplier)
319 || device_is_dependent(consumer, supplier)) {
320 link = NULL;
321 goto out;
322 }
323
324 /*
325 * DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed
326 * longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both
327 * together doesn't make sense, so prefer DL_FLAG_AUTOREMOVE_SUPPLIER.
328 */
329 if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
330 flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
331
332 list_for_each_entry(link, &supplier->links.consumers, s_node) {
333 if (link->consumer != consumer)
334 continue;
335
336 if (flags & DL_FLAG_PM_RUNTIME) {
337 if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
338 pm_runtime_new_link(consumer);
339 link->flags |= DL_FLAG_PM_RUNTIME;
340 }
341 if (flags & DL_FLAG_RPM_ACTIVE)
342 refcount_inc(&link->rpm_active);
343 }
344
345 if (flags & DL_FLAG_STATELESS) {
346 link->flags |= DL_FLAG_STATELESS;
347 kref_get(&link->kref);
348 goto out;
349 }
350
351 /*
352 * If the life time of the link following from the new flags is
353 * longer than indicated by the flags of the existing link,
354 * update the existing link to stay around longer.
355 */
356 if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) {
357 if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
358 link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
359 link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
360 }
361 } else if (!(flags & DL_FLAG_AUTOREMOVE_CONSUMER)) {
362 link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER |
363 DL_FLAG_AUTOREMOVE_SUPPLIER);
364 }
365 if (!(link->flags & DL_FLAG_MANAGED)) {
366 kref_get(&link->kref);
367 link->flags |= DL_FLAG_MANAGED;
368 device_link_init_status(link, consumer, supplier);
369 }
370 goto out;
371 }
372
373 link = kzalloc(sizeof(*link), GFP_KERNEL);
374 if (!link)
375 goto out;
376
377 refcount_set(&link->rpm_active, 1);
378
379 if (flags & DL_FLAG_PM_RUNTIME) {
380 if (flags & DL_FLAG_RPM_ACTIVE)
381 refcount_inc(&link->rpm_active);
382
383 pm_runtime_new_link(consumer);
384 }
385
386 get_device(supplier);
387 link->supplier = supplier;
388 INIT_LIST_HEAD(&link->s_node);
389 get_device(consumer);
390 link->consumer = consumer;
391 INIT_LIST_HEAD(&link->c_node);
392 link->flags = flags;
393 kref_init(&link->kref);
394
395 /* Determine the initial link state. */
396 if (flags & DL_FLAG_STATELESS)
397 link->status = DL_STATE_NONE;
398 else
399 device_link_init_status(link, consumer, supplier);
400
401 /*
402 * Some callers expect the link creation during consumer driver probe to
403 * resume the supplier even without DL_FLAG_RPM_ACTIVE.
404 */
405 if (link->status == DL_STATE_CONSUMER_PROBE &&
406 flags & DL_FLAG_PM_RUNTIME)
407 pm_runtime_resume(supplier);
408
409 /*
410 * Move the consumer and all of the devices depending on it to the end
411 * of dpm_list and the devices_kset list.
412 *
413 * It is necessary to hold dpm_list locked throughout all that or else
414 * we may end up suspending with a wrong ordering of it.
415 */
416 device_reorder_to_tail(consumer, NULL);
417
418 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
419 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
420
421 dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
422
423 out:
424 device_pm_unlock();
425 device_links_write_unlock();
426
427 if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link)
428 pm_runtime_put(supplier);
429
430 return link;
431}
432EXPORT_SYMBOL_GPL(device_link_add);
433
434static void device_link_free(struct device_link *link)
435{
436 while (refcount_dec_not_one(&link->rpm_active))
437 pm_runtime_put(link->supplier);
438
439 put_device(link->consumer);
440 put_device(link->supplier);
441 kfree(link);
442}
443
444#ifdef CONFIG_SRCU
445static void __device_link_free_srcu(struct rcu_head *rhead)
446{
447 device_link_free(container_of(rhead, struct device_link, rcu_head));
448}
449
450static void __device_link_del(struct kref *kref)
451{
452 struct device_link *link = container_of(kref, struct device_link, kref);
453
454 dev_dbg(link->consumer, "Dropping the link to %s\n",
455 dev_name(link->supplier));
456
457 if (link->flags & DL_FLAG_PM_RUNTIME)
458 pm_runtime_drop_link(link->consumer);
459
460 list_del_rcu(&link->s_node);
461 list_del_rcu(&link->c_node);
462 call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
463}
464#else /* !CONFIG_SRCU */
465static void __device_link_del(struct kref *kref)
466{
467 struct device_link *link = container_of(kref, struct device_link, kref);
468
469 dev_info(link->consumer, "Dropping the link to %s\n",
470 dev_name(link->supplier));
471
472 if (link->flags & DL_FLAG_PM_RUNTIME)
473 pm_runtime_drop_link(link->consumer);
474
475 list_del(&link->s_node);
476 list_del(&link->c_node);
477 device_link_free(link);
478}
479#endif /* !CONFIG_SRCU */
480
481static void device_link_put_kref(struct device_link *link)
482{
483 if (link->flags & DL_FLAG_STATELESS)
484 kref_put(&link->kref, __device_link_del);
485 else
486 WARN(1, "Unable to drop a managed device link reference\n");
487}
488
489/**
490 * device_link_del - Delete a stateless link between two devices.
491 * @link: Device link to delete.
492 *
493 * The caller must ensure proper synchronization of this function with runtime
494 * PM. If the link was added multiple times, it needs to be deleted as often.
495 * Care is required for hotplugged devices: Their links are purged on removal
496 * and calling device_link_del() is then no longer allowed.
497 */
498void device_link_del(struct device_link *link)
499{
500 device_links_write_lock();
501 device_pm_lock();
502 device_link_put_kref(link);
503 device_pm_unlock();
504 device_links_write_unlock();
505}
506EXPORT_SYMBOL_GPL(device_link_del);
507
508/**
509 * device_link_remove - Delete a stateless link between two devices.
510 * @consumer: Consumer end of the link.
511 * @supplier: Supplier end of the link.
512 *
513 * The caller must ensure proper synchronization of this function with runtime
514 * PM.
515 */
516void device_link_remove(void *consumer, struct device *supplier)
517{
518 struct device_link *link;
519
520 if (WARN_ON(consumer == supplier))
521 return;
522
523 device_links_write_lock();
524 device_pm_lock();
525
526 list_for_each_entry(link, &supplier->links.consumers, s_node) {
527 if (link->consumer == consumer) {
528 device_link_put_kref(link);
529 break;
530 }
531 }
532
533 device_pm_unlock();
534 device_links_write_unlock();
535}
536EXPORT_SYMBOL_GPL(device_link_remove);
537
538static void device_links_missing_supplier(struct device *dev)
539{
540 struct device_link *link;
541
542 list_for_each_entry(link, &dev->links.suppliers, c_node)
543 if (link->status == DL_STATE_CONSUMER_PROBE)
544 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
545}
546
547/**
548 * device_links_check_suppliers - Check presence of supplier drivers.
549 * @dev: Consumer device.
550 *
551 * Check links from this device to any suppliers. Walk the list of the device's
552 * links to suppliers and see if all of them are available. If not, simply
553 * return -EPROBE_DEFER.
554 *
555 * We need to guarantee that the supplier will not go away after the check has
556 * been positive here. It only can go away in __device_release_driver() and
557 * that function checks the device's links to consumers. This means we need to
558 * mark the link as "consumer probe in progress" to make the supplier removal
559 * wait for us to complete (or bad things may happen).
560 *
561 * Links without the DL_FLAG_MANAGED flag set are ignored.
562 */
563int device_links_check_suppliers(struct device *dev)
564{
565 struct device_link *link;
566 int ret = 0;
567
568 device_links_write_lock();
569
570 list_for_each_entry(link, &dev->links.suppliers, c_node) {
571 if (!(link->flags & DL_FLAG_MANAGED))
572 continue;
573
574 if (link->status != DL_STATE_AVAILABLE) {
575 device_links_missing_supplier(dev);
576 ret = -EPROBE_DEFER;
577 break;
578 }
579 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
580 }
581 dev->links.status = DL_DEV_PROBING;
582
583 device_links_write_unlock();
584 return ret;
585}
586
587/**
588 * device_links_driver_bound - Update device links after probing its driver.
589 * @dev: Device to update the links for.
590 *
591 * The probe has been successful, so update links from this device to any
592 * consumers by changing their status to "available".
593 *
594 * Also change the status of @dev's links to suppliers to "active".
595 *
596 * Links without the DL_FLAG_MANAGED flag set are ignored.
597 */
598void device_links_driver_bound(struct device *dev)
599{
600 struct device_link *link;
601
602 device_links_write_lock();
603
604 list_for_each_entry(link, &dev->links.consumers, s_node) {
605 if (!(link->flags & DL_FLAG_MANAGED))
606 continue;
607
608 /*
609 * Links created during consumer probe may be in the "consumer
610 * probe" state to start with if the supplier is still probing
611 * when they are created and they may become "active" if the
612 * consumer probe returns first. Skip them here.
613 */
614 if (link->status == DL_STATE_CONSUMER_PROBE ||
615 link->status == DL_STATE_ACTIVE)
616 continue;
617
618 WARN_ON(link->status != DL_STATE_DORMANT);
619 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
620
621 if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
622 driver_deferred_probe_add(link->consumer);
623 }
624
625 list_for_each_entry(link, &dev->links.suppliers, c_node) {
626 if (!(link->flags & DL_FLAG_MANAGED))
627 continue;
628
629 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
630 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
631 }
632
633 dev->links.status = DL_DEV_DRIVER_BOUND;
634
635 device_links_write_unlock();
636}
637
638static void device_link_drop_managed(struct device_link *link)
639{
640 link->flags &= ~DL_FLAG_MANAGED;
641 WRITE_ONCE(link->status, DL_STATE_NONE);
642 kref_put(&link->kref, __device_link_del);
643}
644
645/**
646 * __device_links_no_driver - Update links of a device without a driver.
647 * @dev: Device without a drvier.
648 *
649 * Delete all non-persistent links from this device to any suppliers.
650 *
651 * Persistent links stay around, but their status is changed to "available",
652 * unless they already are in the "supplier unbind in progress" state in which
653 * case they need not be updated.
654 *
655 * Links without the DL_FLAG_MANAGED flag set are ignored.
656 */
657static void __device_links_no_driver(struct device *dev)
658{
659 struct device_link *link, *ln;
660
661 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
662 if (!(link->flags & DL_FLAG_MANAGED))
663 continue;
664
665 if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
666 device_link_drop_managed(link);
667 else if (link->status == DL_STATE_CONSUMER_PROBE ||
668 link->status == DL_STATE_ACTIVE)
669 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
670 }
671
672 dev->links.status = DL_DEV_NO_DRIVER;
673}
674
675/**
676 * device_links_no_driver - Update links after failing driver probe.
677 * @dev: Device whose driver has just failed to probe.
678 *
679 * Clean up leftover links to consumers for @dev and invoke
680 * %__device_links_no_driver() to update links to suppliers for it as
681 * appropriate.
682 *
683 * Links without the DL_FLAG_MANAGED flag set are ignored.
684 */
685void device_links_no_driver(struct device *dev)
686{
687 struct device_link *link;
688
689 device_links_write_lock();
690
691 list_for_each_entry(link, &dev->links.consumers, s_node) {
692 if (!(link->flags & DL_FLAG_MANAGED))
693 continue;
694
695 /*
696 * The probe has failed, so if the status of the link is
697 * "consumer probe" or "active", it must have been added by
698 * a probing consumer while this device was still probing.
699 * Change its state to "dormant", as it represents a valid
700 * relationship, but it is not functionally meaningful.
701 */
702 if (link->status == DL_STATE_CONSUMER_PROBE ||
703 link->status == DL_STATE_ACTIVE)
704 WRITE_ONCE(link->status, DL_STATE_DORMANT);
705 }
706
707 __device_links_no_driver(dev);
708
709 device_links_write_unlock();
710}
711
712/**
713 * device_links_driver_cleanup - Update links after driver removal.
714 * @dev: Device whose driver has just gone away.
715 *
716 * Update links to consumers for @dev by changing their status to "dormant" and
717 * invoke %__device_links_no_driver() to update links to suppliers for it as
718 * appropriate.
719 *
720 * Links without the DL_FLAG_MANAGED flag set are ignored.
721 */
722void device_links_driver_cleanup(struct device *dev)
723{
724 struct device_link *link, *ln;
725
726 device_links_write_lock();
727
728 list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) {
729 if (!(link->flags & DL_FLAG_MANAGED))
730 continue;
731
732 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);
733 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
734
735 /*
736 * autoremove the links between this @dev and its consumer
737 * devices that are not active, i.e. where the link state
738 * has moved to DL_STATE_SUPPLIER_UNBIND.
739 */
740 if (link->status == DL_STATE_SUPPLIER_UNBIND &&
741 link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
742 device_link_drop_managed(link);
743
744 WRITE_ONCE(link->status, DL_STATE_DORMANT);
745 }
746
747 __device_links_no_driver(dev);
748
749 device_links_write_unlock();
750}
751
752/**
753 * device_links_busy - Check if there are any busy links to consumers.
754 * @dev: Device to check.
755 *
756 * Check each consumer of the device and return 'true' if its link's status
757 * is one of "consumer probe" or "active" (meaning that the given consumer is
758 * probing right now or its driver is present). Otherwise, change the link
759 * state to "supplier unbind" to prevent the consumer from being probed
760 * successfully going forward.
761 *
762 * Return 'false' if there are no probing or active consumers.
763 *
764 * Links without the DL_FLAG_MANAGED flag set are ignored.
765 */
766bool device_links_busy(struct device *dev)
767{
768 struct device_link *link;
769 bool ret = false;
770
771 device_links_write_lock();
772
773 list_for_each_entry(link, &dev->links.consumers, s_node) {
774 if (!(link->flags & DL_FLAG_MANAGED))
775 continue;
776
777 if (link->status == DL_STATE_CONSUMER_PROBE
778 || link->status == DL_STATE_ACTIVE) {
779 ret = true;
780 break;
781 }
782 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
783 }
784
785 dev->links.status = DL_DEV_UNBINDING;
786
787 device_links_write_unlock();
788 return ret;
789}
790
791/**
792 * device_links_unbind_consumers - Force unbind consumers of the given device.
793 * @dev: Device to unbind the consumers of.
794 *
795 * Walk the list of links to consumers for @dev and if any of them is in the
796 * "consumer probe" state, wait for all device probes in progress to complete
797 * and start over.
798 *
799 * If that's not the case, change the status of the link to "supplier unbind"
800 * and check if the link was in the "active" state. If so, force the consumer
801 * driver to unbind and start over (the consumer will not re-probe as we have
802 * changed the state of the link already).
803 *
804 * Links without the DL_FLAG_MANAGED flag set are ignored.
805 */
806void device_links_unbind_consumers(struct device *dev)
807{
808 struct device_link *link;
809
810 start:
811 device_links_write_lock();
812
813 list_for_each_entry(link, &dev->links.consumers, s_node) {
814 enum device_link_state status;
815
816 if (!(link->flags & DL_FLAG_MANAGED))
817 continue;
818
819 status = link->status;
820 if (status == DL_STATE_CONSUMER_PROBE) {
821 device_links_write_unlock();
822
823 wait_for_device_probe();
824 goto start;
825 }
826 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
827 if (status == DL_STATE_ACTIVE) {
828 struct device *consumer = link->consumer;
829
830 get_device(consumer);
831
832 device_links_write_unlock();
833
834 device_release_driver_internal(consumer, NULL,
835 consumer->parent);
836 put_device(consumer);
837 goto start;
838 }
839 }
840
841 device_links_write_unlock();
842}
843
844/**
845 * device_links_purge - Delete existing links to other devices.
846 * @dev: Target device.
847 */
848static void device_links_purge(struct device *dev)
849{
850 struct device_link *link, *ln;
851
852 /*
853 * Delete all of the remaining links from this device to any other
854 * devices (either consumers or suppliers).
855 */
856 device_links_write_lock();
857
858 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
859 WARN_ON(link->status == DL_STATE_ACTIVE);
860 __device_link_del(&link->kref);
861 }
862
863 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
864 WARN_ON(link->status != DL_STATE_DORMANT &&
865 link->status != DL_STATE_NONE);
866 __device_link_del(&link->kref);
867 }
868
869 device_links_write_unlock();
870}
871
872/* Device links support end. */
873
874int (*platform_notify)(struct device *dev) = NULL;
875int (*platform_notify_remove)(struct device *dev) = NULL;
876static struct kobject *dev_kobj;
877struct kobject *sysfs_dev_char_kobj;
878struct kobject *sysfs_dev_block_kobj;
879
880static DEFINE_MUTEX(device_hotplug_lock);
881
882void lock_device_hotplug(void)
883{
884 mutex_lock(&device_hotplug_lock);
885}
886
887void unlock_device_hotplug(void)
888{
889 mutex_unlock(&device_hotplug_lock);
890}
891
892int lock_device_hotplug_sysfs(void)
893{
894 if (mutex_trylock(&device_hotplug_lock))
895 return 0;
896
897 /* Avoid busy looping (5 ms of sleep should do). */
898 msleep(5);
899 return restart_syscall();
900}
901
902#ifdef CONFIG_BLOCK
903static inline int device_is_not_partition(struct device *dev)
904{
905 return !(dev->type == &part_type);
906}
907#else
908static inline int device_is_not_partition(struct device *dev)
909{
910 return 1;
911}
912#endif
913
914static int
915device_platform_notify(struct device *dev, enum kobject_action action)
916{
917 int ret;
918
919 ret = acpi_platform_notify(dev, action);
920 if (ret)
921 return ret;
922
923 ret = software_node_notify(dev, action);
924 if (ret)
925 return ret;
926
927 if (platform_notify && action == KOBJ_ADD)
928 platform_notify(dev);
929 else if (platform_notify_remove && action == KOBJ_REMOVE)
930 platform_notify_remove(dev);
931 return 0;
932}
933
934/**
935 * dev_driver_string - Return a device's driver name, if at all possible
936 * @dev: struct device to get the name of
937 *
938 * Will return the device's driver's name if it is bound to a device. If
939 * the device is not bound to a driver, it will return the name of the bus
940 * it is attached to. If it is not attached to a bus either, an empty
941 * string will be returned.
942 */
943const char *dev_driver_string(const struct device *dev)
944{
945 struct device_driver *drv;
946
947 /* dev->driver can change to NULL underneath us because of unbinding,
948 * so be careful about accessing it. dev->bus and dev->class should
949 * never change once they are set, so they don't need special care.
950 */
951 drv = READ_ONCE(dev->driver);
952 return drv ? drv->name :
953 (dev->bus ? dev->bus->name :
954 (dev->class ? dev->class->name : ""));
955}
956EXPORT_SYMBOL(dev_driver_string);
957
958#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
959
960static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
961 char *buf)
962{
963 struct device_attribute *dev_attr = to_dev_attr(attr);
964 struct device *dev = kobj_to_dev(kobj);
965 ssize_t ret = -EIO;
966
967 if (dev_attr->show)
968 ret = dev_attr->show(dev, dev_attr, buf);
969 if (ret >= (ssize_t)PAGE_SIZE) {
970 printk("dev_attr_show: %pS returned bad count\n",
971 dev_attr->show);
972 }
973 return ret;
974}
975
976static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
977 const char *buf, size_t count)
978{
979 struct device_attribute *dev_attr = to_dev_attr(attr);
980 struct device *dev = kobj_to_dev(kobj);
981 ssize_t ret = -EIO;
982
983 if (dev_attr->store)
984 ret = dev_attr->store(dev, dev_attr, buf, count);
985 return ret;
986}
987
988static const struct sysfs_ops dev_sysfs_ops = {
989 .show = dev_attr_show,
990 .store = dev_attr_store,
991};
992
993#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
994
995ssize_t device_store_ulong(struct device *dev,
996 struct device_attribute *attr,
997 const char *buf, size_t size)
998{
999 struct dev_ext_attribute *ea = to_ext_attr(attr);
1000 int ret;
1001 unsigned long new;
1002
1003 ret = kstrtoul(buf, 0, &new);
1004 if (ret)
1005 return ret;
1006 *(unsigned long *)(ea->var) = new;
1007 /* Always return full write size even if we didn't consume all */
1008 return size;
1009}
1010EXPORT_SYMBOL_GPL(device_store_ulong);
1011
1012ssize_t device_show_ulong(struct device *dev,
1013 struct device_attribute *attr,
1014 char *buf)
1015{
1016 struct dev_ext_attribute *ea = to_ext_attr(attr);
1017 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
1018}
1019EXPORT_SYMBOL_GPL(device_show_ulong);
1020
1021ssize_t device_store_int(struct device *dev,
1022 struct device_attribute *attr,
1023 const char *buf, size_t size)
1024{
1025 struct dev_ext_attribute *ea = to_ext_attr(attr);
1026 int ret;
1027 long new;
1028
1029 ret = kstrtol(buf, 0, &new);
1030 if (ret)
1031 return ret;
1032
1033 if (new > INT_MAX || new < INT_MIN)
1034 return -EINVAL;
1035 *(int *)(ea->var) = new;
1036 /* Always return full write size even if we didn't consume all */
1037 return size;
1038}
1039EXPORT_SYMBOL_GPL(device_store_int);
1040
1041ssize_t device_show_int(struct device *dev,
1042 struct device_attribute *attr,
1043 char *buf)
1044{
1045 struct dev_ext_attribute *ea = to_ext_attr(attr);
1046
1047 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
1048}
1049EXPORT_SYMBOL_GPL(device_show_int);
1050
1051ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
1052 const char *buf, size_t size)
1053{
1054 struct dev_ext_attribute *ea = to_ext_attr(attr);
1055
1056 if (strtobool(buf, ea->var) < 0)
1057 return -EINVAL;
1058
1059 return size;
1060}
1061EXPORT_SYMBOL_GPL(device_store_bool);
1062
1063ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
1064 char *buf)
1065{
1066 struct dev_ext_attribute *ea = to_ext_attr(attr);
1067
1068 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
1069}
1070EXPORT_SYMBOL_GPL(device_show_bool);
1071
1072/**
1073 * device_release - free device structure.
1074 * @kobj: device's kobject.
1075 *
1076 * This is called once the reference count for the object
1077 * reaches 0. We forward the call to the device's release
1078 * method, which should handle actually freeing the structure.
1079 */
1080static void device_release(struct kobject *kobj)
1081{
1082 struct device *dev = kobj_to_dev(kobj);
1083 struct device_private *p = dev->p;
1084
1085 /*
1086 * Some platform devices are driven without driver attached
1087 * and managed resources may have been acquired. Make sure
1088 * all resources are released.
1089 *
1090 * Drivers still can add resources into device after device
1091 * is deleted but alive, so release devres here to avoid
1092 * possible memory leak.
1093 */
1094 devres_release_all(dev);
1095
1096 if (dev->release)
1097 dev->release(dev);
1098 else if (dev->type && dev->type->release)
1099 dev->type->release(dev);
1100 else if (dev->class && dev->class->dev_release)
1101 dev->class->dev_release(dev);
1102 else
1103 WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.\n",
1104 dev_name(dev));
1105 kfree(p);
1106}
1107
1108static const void *device_namespace(struct kobject *kobj)
1109{
1110 struct device *dev = kobj_to_dev(kobj);
1111 const void *ns = NULL;
1112
1113 if (dev->class && dev->class->ns_type)
1114 ns = dev->class->namespace(dev);
1115
1116 return ns;
1117}
1118
1119static void device_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
1120{
1121 struct device *dev = kobj_to_dev(kobj);
1122
1123 if (dev->class && dev->class->get_ownership)
1124 dev->class->get_ownership(dev, uid, gid);
1125}
1126
1127static struct kobj_type device_ktype = {
1128 .release = device_release,
1129 .sysfs_ops = &dev_sysfs_ops,
1130 .namespace = device_namespace,
1131 .get_ownership = device_get_ownership,
1132};
1133
1134
1135static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
1136{
1137 struct kobj_type *ktype = get_ktype(kobj);
1138
1139 if (ktype == &device_ktype) {
1140 struct device *dev = kobj_to_dev(kobj);
1141 if (dev->bus)
1142 return 1;
1143 if (dev->class)
1144 return 1;
1145 }
1146 return 0;
1147}
1148
1149static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
1150{
1151 struct device *dev = kobj_to_dev(kobj);
1152
1153 if (dev->bus)
1154 return dev->bus->name;
1155 if (dev->class)
1156 return dev->class->name;
1157 return NULL;
1158}
1159
1160static int dev_uevent(struct kset *kset, struct kobject *kobj,
1161 struct kobj_uevent_env *env)
1162{
1163 struct device *dev = kobj_to_dev(kobj);
1164 int retval = 0;
1165
1166 /* add device node properties if present */
1167 if (MAJOR(dev->devt)) {
1168 const char *tmp;
1169 const char *name;
1170 umode_t mode = 0;
1171 kuid_t uid = GLOBAL_ROOT_UID;
1172 kgid_t gid = GLOBAL_ROOT_GID;
1173
1174 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
1175 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
1176 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
1177 if (name) {
1178 add_uevent_var(env, "DEVNAME=%s", name);
1179 if (mode)
1180 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
1181 if (!uid_eq(uid, GLOBAL_ROOT_UID))
1182 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
1183 if (!gid_eq(gid, GLOBAL_ROOT_GID))
1184 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
1185 kfree(tmp);
1186 }
1187 }
1188
1189 if (dev->type && dev->type->name)
1190 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
1191
1192 if (dev->driver)
1193 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
1194
1195 /* Add common DT information about the device */
1196 of_device_uevent(dev, env);
1197
1198 /* have the bus specific function add its stuff */
1199 if (dev->bus && dev->bus->uevent) {
1200 retval = dev->bus->uevent(dev, env);
1201 if (retval)
1202 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
1203 dev_name(dev), __func__, retval);
1204 }
1205
1206 /* have the class specific function add its stuff */
1207 if (dev->class && dev->class->dev_uevent) {
1208 retval = dev->class->dev_uevent(dev, env);
1209 if (retval)
1210 pr_debug("device: '%s': %s: class uevent() "
1211 "returned %d\n", dev_name(dev),
1212 __func__, retval);
1213 }
1214
1215 /* have the device type specific function add its stuff */
1216 if (dev->type && dev->type->uevent) {
1217 retval = dev->type->uevent(dev, env);
1218 if (retval)
1219 pr_debug("device: '%s': %s: dev_type uevent() "
1220 "returned %d\n", dev_name(dev),
1221 __func__, retval);
1222 }
1223
1224 return retval;
1225}
1226
1227static const struct kset_uevent_ops device_uevent_ops = {
1228 .filter = dev_uevent_filter,
1229 .name = dev_uevent_name,
1230 .uevent = dev_uevent,
1231};
1232
1233static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
1234 char *buf)
1235{
1236 struct kobject *top_kobj;
1237 struct kset *kset;
1238 struct kobj_uevent_env *env = NULL;
1239 int i;
1240 size_t count = 0;
1241 int retval;
1242
1243 /* search the kset, the device belongs to */
1244 top_kobj = &dev->kobj;
1245 while (!top_kobj->kset && top_kobj->parent)
1246 top_kobj = top_kobj->parent;
1247 if (!top_kobj->kset)
1248 goto out;
1249
1250 kset = top_kobj->kset;
1251 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
1252 goto out;
1253
1254 /* respect filter */
1255 if (kset->uevent_ops && kset->uevent_ops->filter)
1256 if (!kset->uevent_ops->filter(kset, &dev->kobj))
1257 goto out;
1258
1259 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
1260 if (!env)
1261 return -ENOMEM;
1262
1263 /* let the kset specific function add its keys */
1264 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
1265 if (retval)
1266 goto out;
1267
1268 /* copy keys to file */
1269 for (i = 0; i < env->envp_idx; i++)
1270 count += sprintf(&buf[count], "%s\n", env->envp[i]);
1271out:
1272 kfree(env);
1273 return count;
1274}
1275
1276static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
1277 const char *buf, size_t count)
1278{
1279 int rc;
1280
1281 rc = kobject_synth_uevent(&dev->kobj, buf, count);
1282
1283 if (rc) {
1284 dev_err(dev, "uevent: failed to send synthetic uevent\n");
1285 return rc;
1286 }
1287
1288 return count;
1289}
1290static DEVICE_ATTR_RW(uevent);
1291
1292static ssize_t online_show(struct device *dev, struct device_attribute *attr,
1293 char *buf)
1294{
1295 bool val;
1296
1297 device_lock(dev);
1298 val = !dev->offline;
1299 device_unlock(dev);
1300 return sprintf(buf, "%u\n", val);
1301}
1302
1303static ssize_t online_store(struct device *dev, struct device_attribute *attr,
1304 const char *buf, size_t count)
1305{
1306 bool val;
1307 int ret;
1308
1309 ret = strtobool(buf, &val);
1310 if (ret < 0)
1311 return ret;
1312
1313 ret = lock_device_hotplug_sysfs();
1314 if (ret)
1315 return ret;
1316
1317 ret = val ? device_online(dev) : device_offline(dev);
1318 unlock_device_hotplug();
1319 return ret < 0 ? ret : count;
1320}
1321static DEVICE_ATTR_RW(online);
1322
1323int device_add_groups(struct device *dev, const struct attribute_group **groups)
1324{
1325 return sysfs_create_groups(&dev->kobj, groups);
1326}
1327EXPORT_SYMBOL_GPL(device_add_groups);
1328
1329void device_remove_groups(struct device *dev,
1330 const struct attribute_group **groups)
1331{
1332 sysfs_remove_groups(&dev->kobj, groups);
1333}
1334EXPORT_SYMBOL_GPL(device_remove_groups);
1335
1336union device_attr_group_devres {
1337 const struct attribute_group *group;
1338 const struct attribute_group **groups;
1339};
1340
1341static int devm_attr_group_match(struct device *dev, void *res, void *data)
1342{
1343 return ((union device_attr_group_devres *)res)->group == data;
1344}
1345
1346static void devm_attr_group_remove(struct device *dev, void *res)
1347{
1348 union device_attr_group_devres *devres = res;
1349 const struct attribute_group *group = devres->group;
1350
1351 dev_dbg(dev, "%s: removing group %p\n", __func__, group);
1352 sysfs_remove_group(&dev->kobj, group);
1353}
1354
1355static void devm_attr_groups_remove(struct device *dev, void *res)
1356{
1357 union device_attr_group_devres *devres = res;
1358 const struct attribute_group **groups = devres->groups;
1359
1360 dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
1361 sysfs_remove_groups(&dev->kobj, groups);
1362}
1363
1364/**
1365 * devm_device_add_group - given a device, create a managed attribute group
1366 * @dev: The device to create the group for
1367 * @grp: The attribute group to create
1368 *
1369 * This function creates a group for the first time. It will explicitly
1370 * warn and error if any of the attribute files being created already exist.
1371 *
1372 * Returns 0 on success or error code on failure.
1373 */
1374int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
1375{
1376 union device_attr_group_devres *devres;
1377 int error;
1378
1379 devres = devres_alloc(devm_attr_group_remove,
1380 sizeof(*devres), GFP_KERNEL);
1381 if (!devres)
1382 return -ENOMEM;
1383
1384 error = sysfs_create_group(&dev->kobj, grp);
1385 if (error) {
1386 devres_free(devres);
1387 return error;
1388 }
1389
1390 devres->group = grp;
1391 devres_add(dev, devres);
1392 return 0;
1393}
1394EXPORT_SYMBOL_GPL(devm_device_add_group);
1395
1396/**
1397 * devm_device_remove_group: remove a managed group from a device
1398 * @dev: device to remove the group from
1399 * @grp: group to remove
1400 *
1401 * This function removes a group of attributes from a device. The attributes
1402 * previously have to have been created for this group, otherwise it will fail.
1403 */
1404void devm_device_remove_group(struct device *dev,
1405 const struct attribute_group *grp)
1406{
1407 WARN_ON(devres_release(dev, devm_attr_group_remove,
1408 devm_attr_group_match,
1409 /* cast away const */ (void *)grp));
1410}
1411EXPORT_SYMBOL_GPL(devm_device_remove_group);
1412
1413/**
1414 * devm_device_add_groups - create a bunch of managed attribute groups
1415 * @dev: The device to create the group for
1416 * @groups: The attribute groups to create, NULL terminated
1417 *
1418 * This function creates a bunch of managed attribute groups. If an error
1419 * occurs when creating a group, all previously created groups will be
1420 * removed, unwinding everything back to the original state when this
1421 * function was called. It will explicitly warn and error if any of the
1422 * attribute files being created already exist.
1423 *
1424 * Returns 0 on success or error code from sysfs_create_group on failure.
1425 */
1426int devm_device_add_groups(struct device *dev,
1427 const struct attribute_group **groups)
1428{
1429 union device_attr_group_devres *devres;
1430 int error;
1431
1432 devres = devres_alloc(devm_attr_groups_remove,
1433 sizeof(*devres), GFP_KERNEL);
1434 if (!devres)
1435 return -ENOMEM;
1436
1437 error = sysfs_create_groups(&dev->kobj, groups);
1438 if (error) {
1439 devres_free(devres);
1440 return error;
1441 }
1442
1443 devres->groups = groups;
1444 devres_add(dev, devres);
1445 return 0;
1446}
1447EXPORT_SYMBOL_GPL(devm_device_add_groups);
1448
1449/**
1450 * devm_device_remove_groups - remove a list of managed groups
1451 *
1452 * @dev: The device for the groups to be removed from
1453 * @groups: NULL terminated list of groups to be removed
1454 *
1455 * If groups is not NULL, remove the specified groups from the device.
1456 */
1457void devm_device_remove_groups(struct device *dev,
1458 const struct attribute_group **groups)
1459{
1460 WARN_ON(devres_release(dev, devm_attr_groups_remove,
1461 devm_attr_group_match,
1462 /* cast away const */ (void *)groups));
1463}
1464EXPORT_SYMBOL_GPL(devm_device_remove_groups);
1465
1466static int device_add_attrs(struct device *dev)
1467{
1468 struct class *class = dev->class;
1469 const struct device_type *type = dev->type;
1470 int error;
1471
1472 if (class) {
1473 error = device_add_groups(dev, class->dev_groups);
1474 if (error)
1475 return error;
1476 }
1477
1478 if (type) {
1479 error = device_add_groups(dev, type->groups);
1480 if (error)
1481 goto err_remove_class_groups;
1482 }
1483
1484 error = device_add_groups(dev, dev->groups);
1485 if (error)
1486 goto err_remove_type_groups;
1487
1488 if (device_supports_offline(dev) && !dev->offline_disabled) {
1489 error = device_create_file(dev, &dev_attr_online);
1490 if (error)
1491 goto err_remove_dev_groups;
1492 }
1493
1494 return 0;
1495
1496 err_remove_dev_groups:
1497 device_remove_groups(dev, dev->groups);
1498 err_remove_type_groups:
1499 if (type)
1500 device_remove_groups(dev, type->groups);
1501 err_remove_class_groups:
1502 if (class)
1503 device_remove_groups(dev, class->dev_groups);
1504
1505 return error;
1506}
1507
1508static void device_remove_attrs(struct device *dev)
1509{
1510 struct class *class = dev->class;
1511 const struct device_type *type = dev->type;
1512
1513 device_remove_file(dev, &dev_attr_online);
1514 device_remove_groups(dev, dev->groups);
1515
1516 if (type)
1517 device_remove_groups(dev, type->groups);
1518
1519 if (class)
1520 device_remove_groups(dev, class->dev_groups);
1521}
1522
1523static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
1524 char *buf)
1525{
1526 return print_dev_t(buf, dev->devt);
1527}
1528static DEVICE_ATTR_RO(dev);
1529
1530/* /sys/devices/ */
1531struct kset *devices_kset;
1532
1533/**
1534 * devices_kset_move_before - Move device in the devices_kset's list.
1535 * @deva: Device to move.
1536 * @devb: Device @deva should come before.
1537 */
1538static void devices_kset_move_before(struct device *deva, struct device *devb)
1539{
1540 if (!devices_kset)
1541 return;
1542 pr_debug("devices_kset: Moving %s before %s\n",
1543 dev_name(deva), dev_name(devb));
1544 spin_lock(&devices_kset->list_lock);
1545 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
1546 spin_unlock(&devices_kset->list_lock);
1547}
1548
1549/**
1550 * devices_kset_move_after - Move device in the devices_kset's list.
1551 * @deva: Device to move
1552 * @devb: Device @deva should come after.
1553 */
1554static void devices_kset_move_after(struct device *deva, struct device *devb)
1555{
1556 if (!devices_kset)
1557 return;
1558 pr_debug("devices_kset: Moving %s after %s\n",
1559 dev_name(deva), dev_name(devb));
1560 spin_lock(&devices_kset->list_lock);
1561 list_move(&deva->kobj.entry, &devb->kobj.entry);
1562 spin_unlock(&devices_kset->list_lock);
1563}
1564
1565/**
1566 * devices_kset_move_last - move the device to the end of devices_kset's list.
1567 * @dev: device to move
1568 */
1569void devices_kset_move_last(struct device *dev)
1570{
1571 if (!devices_kset)
1572 return;
1573 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
1574 spin_lock(&devices_kset->list_lock);
1575 list_move_tail(&dev->kobj.entry, &devices_kset->list);
1576 spin_unlock(&devices_kset->list_lock);
1577}
1578
1579/**
1580 * device_create_file - create sysfs attribute file for device.
1581 * @dev: device.
1582 * @attr: device attribute descriptor.
1583 */
1584int device_create_file(struct device *dev,
1585 const struct device_attribute *attr)
1586{
1587 int error = 0;
1588
1589 if (dev) {
1590 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
1591 "Attribute %s: write permission without 'store'\n",
1592 attr->attr.name);
1593 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
1594 "Attribute %s: read permission without 'show'\n",
1595 attr->attr.name);
1596 error = sysfs_create_file(&dev->kobj, &attr->attr);
1597 }
1598
1599 return error;
1600}
1601EXPORT_SYMBOL_GPL(device_create_file);
1602
1603/**
1604 * device_remove_file - remove sysfs attribute file.
1605 * @dev: device.
1606 * @attr: device attribute descriptor.
1607 */
1608void device_remove_file(struct device *dev,
1609 const struct device_attribute *attr)
1610{
1611 if (dev)
1612 sysfs_remove_file(&dev->kobj, &attr->attr);
1613}
1614EXPORT_SYMBOL_GPL(device_remove_file);
1615
1616/**
1617 * device_remove_file_self - remove sysfs attribute file from its own method.
1618 * @dev: device.
1619 * @attr: device attribute descriptor.
1620 *
1621 * See kernfs_remove_self() for details.
1622 */
1623bool device_remove_file_self(struct device *dev,
1624 const struct device_attribute *attr)
1625{
1626 if (dev)
1627 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
1628 else
1629 return false;
1630}
1631EXPORT_SYMBOL_GPL(device_remove_file_self);
1632
1633/**
1634 * device_create_bin_file - create sysfs binary attribute file for device.
1635 * @dev: device.
1636 * @attr: device binary attribute descriptor.
1637 */
1638int device_create_bin_file(struct device *dev,
1639 const struct bin_attribute *attr)
1640{
1641 int error = -EINVAL;
1642 if (dev)
1643 error = sysfs_create_bin_file(&dev->kobj, attr);
1644 return error;
1645}
1646EXPORT_SYMBOL_GPL(device_create_bin_file);
1647
1648/**
1649 * device_remove_bin_file - remove sysfs binary attribute file
1650 * @dev: device.
1651 * @attr: device binary attribute descriptor.
1652 */
1653void device_remove_bin_file(struct device *dev,
1654 const struct bin_attribute *attr)
1655{
1656 if (dev)
1657 sysfs_remove_bin_file(&dev->kobj, attr);
1658}
1659EXPORT_SYMBOL_GPL(device_remove_bin_file);
1660
1661static void klist_children_get(struct klist_node *n)
1662{
1663 struct device_private *p = to_device_private_parent(n);
1664 struct device *dev = p->device;
1665
1666 get_device(dev);
1667}
1668
1669static void klist_children_put(struct klist_node *n)
1670{
1671 struct device_private *p = to_device_private_parent(n);
1672 struct device *dev = p->device;
1673
1674 put_device(dev);
1675}
1676
1677/**
1678 * device_initialize - init device structure.
1679 * @dev: device.
1680 *
1681 * This prepares the device for use by other layers by initializing
1682 * its fields.
1683 * It is the first half of device_register(), if called by
1684 * that function, though it can also be called separately, so one
1685 * may use @dev's fields. In particular, get_device()/put_device()
1686 * may be used for reference counting of @dev after calling this
1687 * function.
1688 *
1689 * All fields in @dev must be initialized by the caller to 0, except
1690 * for those explicitly set to some other value. The simplest
1691 * approach is to use kzalloc() to allocate the structure containing
1692 * @dev.
1693 *
1694 * NOTE: Use put_device() to give up your reference instead of freeing
1695 * @dev directly once you have called this function.
1696 */
1697void device_initialize(struct device *dev)
1698{
1699 dev->kobj.kset = devices_kset;
1700 kobject_init(&dev->kobj, &device_ktype);
1701 INIT_LIST_HEAD(&dev->dma_pools);
1702 mutex_init(&dev->mutex);
1703#ifdef CONFIG_PROVE_LOCKING
1704 mutex_init(&dev->lockdep_mutex);
1705#endif
1706 lockdep_set_novalidate_class(&dev->mutex);
1707 spin_lock_init(&dev->devres_lock);
1708 INIT_LIST_HEAD(&dev->devres_head);
1709 device_pm_init(dev);
1710 set_dev_node(dev, -1);
1711#ifdef CONFIG_GENERIC_MSI_IRQ
1712 INIT_LIST_HEAD(&dev->msi_list);
1713#endif
1714 INIT_LIST_HEAD(&dev->links.consumers);
1715 INIT_LIST_HEAD(&dev->links.suppliers);
1716 dev->links.status = DL_DEV_NO_DRIVER;
1717}
1718EXPORT_SYMBOL_GPL(device_initialize);
1719
1720struct kobject *virtual_device_parent(struct device *dev)
1721{
1722 static struct kobject *virtual_dir = NULL;
1723
1724 if (!virtual_dir)
1725 virtual_dir = kobject_create_and_add("virtual",
1726 &devices_kset->kobj);
1727
1728 return virtual_dir;
1729}
1730
1731struct class_dir {
1732 struct kobject kobj;
1733 struct class *class;
1734};
1735
1736#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1737
1738static void class_dir_release(struct kobject *kobj)
1739{
1740 struct class_dir *dir = to_class_dir(kobj);
1741 kfree(dir);
1742}
1743
1744static const
1745struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
1746{
1747 struct class_dir *dir = to_class_dir(kobj);
1748 return dir->class->ns_type;
1749}
1750
1751static struct kobj_type class_dir_ktype = {
1752 .release = class_dir_release,
1753 .sysfs_ops = &kobj_sysfs_ops,
1754 .child_ns_type = class_dir_child_ns_type
1755};
1756
1757static struct kobject *
1758class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
1759{
1760 struct class_dir *dir;
1761 int retval;
1762
1763 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1764 if (!dir)
1765 return ERR_PTR(-ENOMEM);
1766
1767 dir->class = class;
1768 kobject_init(&dir->kobj, &class_dir_ktype);
1769
1770 dir->kobj.kset = &class->p->glue_dirs;
1771
1772 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
1773 if (retval < 0) {
1774 kobject_put(&dir->kobj);
1775 return ERR_PTR(retval);
1776 }
1777 return &dir->kobj;
1778}
1779
1780static DEFINE_MUTEX(gdp_mutex);
1781
1782static struct kobject *get_device_parent(struct device *dev,
1783 struct device *parent)
1784{
1785 if (dev->class) {
1786 struct kobject *kobj = NULL;
1787 struct kobject *parent_kobj;
1788 struct kobject *k;
1789
1790#ifdef CONFIG_BLOCK
1791 /* block disks show up in /sys/block */
1792 if (sysfs_deprecated && dev->class == &block_class) {
1793 if (parent && parent->class == &block_class)
1794 return &parent->kobj;
1795 return &block_class.p->subsys.kobj;
1796 }
1797#endif
1798
1799 /*
1800 * If we have no parent, we live in "virtual".
1801 * Class-devices with a non class-device as parent, live
1802 * in a "glue" directory to prevent namespace collisions.
1803 */
1804 if (parent == NULL)
1805 parent_kobj = virtual_device_parent(dev);
1806 else if (parent->class && !dev->class->ns_type)
1807 return &parent->kobj;
1808 else
1809 parent_kobj = &parent->kobj;
1810
1811 mutex_lock(&gdp_mutex);
1812
1813 /* find our class-directory at the parent and reference it */
1814 spin_lock(&dev->class->p->glue_dirs.list_lock);
1815 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
1816 if (k->parent == parent_kobj) {
1817 kobj = kobject_get(k);
1818 break;
1819 }
1820 spin_unlock(&dev->class->p->glue_dirs.list_lock);
1821 if (kobj) {
1822 mutex_unlock(&gdp_mutex);
1823 return kobj;
1824 }
1825
1826 /* or create a new class-directory at the parent device */
1827 k = class_dir_create_and_add(dev->class, parent_kobj);
1828 /* do not emit an uevent for this simple "glue" directory */
1829 mutex_unlock(&gdp_mutex);
1830 return k;
1831 }
1832
1833 /* subsystems can specify a default root directory for their devices */
1834 if (!parent && dev->bus && dev->bus->dev_root)
1835 return &dev->bus->dev_root->kobj;
1836
1837 if (parent)
1838 return &parent->kobj;
1839 return NULL;
1840}
1841
1842static inline bool live_in_glue_dir(struct kobject *kobj,
1843 struct device *dev)
1844{
1845 if (!kobj || !dev->class ||
1846 kobj->kset != &dev->class->p->glue_dirs)
1847 return false;
1848 return true;
1849}
1850
1851static inline struct kobject *get_glue_dir(struct device *dev)
1852{
1853 return dev->kobj.parent;
1854}
1855
1856/*
1857 * make sure cleaning up dir as the last step, we need to make
1858 * sure .release handler of kobject is run with holding the
1859 * global lock
1860 */
1861static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
1862{
1863 unsigned int ref;
1864
1865 /* see if we live in a "glue" directory */
1866 if (!live_in_glue_dir(glue_dir, dev))
1867 return;
1868
1869 mutex_lock(&gdp_mutex);
1870 /**
1871 * There is a race condition between removing glue directory
1872 * and adding a new device under the glue directory.
1873 *
1874 * CPU1: CPU2:
1875 *
1876 * device_add()
1877 * get_device_parent()
1878 * class_dir_create_and_add()
1879 * kobject_add_internal()
1880 * create_dir() // create glue_dir
1881 *
1882 * device_add()
1883 * get_device_parent()
1884 * kobject_get() // get glue_dir
1885 *
1886 * device_del()
1887 * cleanup_glue_dir()
1888 * kobject_del(glue_dir)
1889 *
1890 * kobject_add()
1891 * kobject_add_internal()
1892 * create_dir() // in glue_dir
1893 * sysfs_create_dir_ns()
1894 * kernfs_create_dir_ns(sd)
1895 *
1896 * sysfs_remove_dir() // glue_dir->sd=NULL
1897 * sysfs_put() // free glue_dir->sd
1898 *
1899 * // sd is freed
1900 * kernfs_new_node(sd)
1901 * kernfs_get(glue_dir)
1902 * kernfs_add_one()
1903 * kernfs_put()
1904 *
1905 * Before CPU1 remove last child device under glue dir, if CPU2 add
1906 * a new device under glue dir, the glue_dir kobject reference count
1907 * will be increase to 2 in kobject_get(k). And CPU2 has been called
1908 * kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir()
1909 * and sysfs_put(). This result in glue_dir->sd is freed.
1910 *
1911 * Then the CPU2 will see a stale "empty" but still potentially used
1912 * glue dir around in kernfs_new_node().
1913 *
1914 * In order to avoid this happening, we also should make sure that
1915 * kernfs_node for glue_dir is released in CPU1 only when refcount
1916 * for glue_dir kobj is 1.
1917 */
1918 ref = kref_read(&glue_dir->kref);
1919 if (!kobject_has_children(glue_dir) && !--ref)
1920 kobject_del(glue_dir);
1921 kobject_put(glue_dir);
1922 mutex_unlock(&gdp_mutex);
1923}
1924
1925static int device_add_class_symlinks(struct device *dev)
1926{
1927 struct device_node *of_node = dev_of_node(dev);
1928 int error;
1929
1930 if (of_node) {
1931 error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
1932 if (error)
1933 dev_warn(dev, "Error %d creating of_node link\n",error);
1934 /* An error here doesn't warrant bringing down the device */
1935 }
1936
1937 if (!dev->class)
1938 return 0;
1939
1940 error = sysfs_create_link(&dev->kobj,
1941 &dev->class->p->subsys.kobj,
1942 "subsystem");
1943 if (error)
1944 goto out_devnode;
1945
1946 if (dev->parent && device_is_not_partition(dev)) {
1947 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
1948 "device");
1949 if (error)
1950 goto out_subsys;
1951 }
1952
1953#ifdef CONFIG_BLOCK
1954 /* /sys/block has directories and does not need symlinks */
1955 if (sysfs_deprecated && dev->class == &block_class)
1956 return 0;
1957#endif
1958
1959 /* link in the class directory pointing to the device */
1960 error = sysfs_create_link(&dev->class->p->subsys.kobj,
1961 &dev->kobj, dev_name(dev));
1962 if (error)
1963 goto out_device;
1964
1965 return 0;
1966
1967out_device:
1968 sysfs_remove_link(&dev->kobj, "device");
1969
1970out_subsys:
1971 sysfs_remove_link(&dev->kobj, "subsystem");
1972out_devnode:
1973 sysfs_remove_link(&dev->kobj, "of_node");
1974 return error;
1975}
1976
1977static void device_remove_class_symlinks(struct device *dev)
1978{
1979 if (dev_of_node(dev))
1980 sysfs_remove_link(&dev->kobj, "of_node");
1981
1982 if (!dev->class)
1983 return;
1984
1985 if (dev->parent && device_is_not_partition(dev))
1986 sysfs_remove_link(&dev->kobj, "device");
1987 sysfs_remove_link(&dev->kobj, "subsystem");
1988#ifdef CONFIG_BLOCK
1989 if (sysfs_deprecated && dev->class == &block_class)
1990 return;
1991#endif
1992 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
1993}
1994
1995/**
1996 * dev_set_name - set a device name
1997 * @dev: device
1998 * @fmt: format string for the device's name
1999 */
2000int dev_set_name(struct device *dev, const char *fmt, ...)
2001{
2002 va_list vargs;
2003 int err;
2004
2005 va_start(vargs, fmt);
2006 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
2007 va_end(vargs);
2008 return err;
2009}
2010EXPORT_SYMBOL_GPL(dev_set_name);
2011
2012/**
2013 * device_to_dev_kobj - select a /sys/dev/ directory for the device
2014 * @dev: device
2015 *
2016 * By default we select char/ for new entries. Setting class->dev_obj
2017 * to NULL prevents an entry from being created. class->dev_kobj must
2018 * be set (or cleared) before any devices are registered to the class
2019 * otherwise device_create_sys_dev_entry() and
2020 * device_remove_sys_dev_entry() will disagree about the presence of
2021 * the link.
2022 */
2023static struct kobject *device_to_dev_kobj(struct device *dev)
2024{
2025 struct kobject *kobj;
2026
2027 if (dev->class)
2028 kobj = dev->class->dev_kobj;
2029 else
2030 kobj = sysfs_dev_char_kobj;
2031
2032 return kobj;
2033}
2034
2035static int device_create_sys_dev_entry(struct device *dev)
2036{
2037 struct kobject *kobj = device_to_dev_kobj(dev);
2038 int error = 0;
2039 char devt_str[15];
2040
2041 if (kobj) {
2042 format_dev_t(devt_str, dev->devt);
2043 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
2044 }
2045
2046 return error;
2047}
2048
2049static void device_remove_sys_dev_entry(struct device *dev)
2050{
2051 struct kobject *kobj = device_to_dev_kobj(dev);
2052 char devt_str[15];
2053
2054 if (kobj) {
2055 format_dev_t(devt_str, dev->devt);
2056 sysfs_remove_link(kobj, devt_str);
2057 }
2058}
2059
2060static int device_private_init(struct device *dev)
2061{
2062 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
2063 if (!dev->p)
2064 return -ENOMEM;
2065 dev->p->device = dev;
2066 klist_init(&dev->p->klist_children, klist_children_get,
2067 klist_children_put);
2068 INIT_LIST_HEAD(&dev->p->deferred_probe);
2069 return 0;
2070}
2071
2072/**
2073 * device_add - add device to device hierarchy.
2074 * @dev: device.
2075 *
2076 * This is part 2 of device_register(), though may be called
2077 * separately _iff_ device_initialize() has been called separately.
2078 *
2079 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
2080 * to the global and sibling lists for the device, then
2081 * adds it to the other relevant subsystems of the driver model.
2082 *
2083 * Do not call this routine or device_register() more than once for
2084 * any device structure. The driver model core is not designed to work
2085 * with devices that get unregistered and then spring back to life.
2086 * (Among other things, it's very hard to guarantee that all references
2087 * to the previous incarnation of @dev have been dropped.) Allocate
2088 * and register a fresh new struct device instead.
2089 *
2090 * NOTE: _Never_ directly free @dev after calling this function, even
2091 * if it returned an error! Always use put_device() to give up your
2092 * reference instead.
2093 *
2094 * Rule of thumb is: if device_add() succeeds, you should call
2095 * device_del() when you want to get rid of it. If device_add() has
2096 * *not* succeeded, use *only* put_device() to drop the reference
2097 * count.
2098 */
2099int device_add(struct device *dev)
2100{
2101 struct device *parent;
2102 struct kobject *kobj;
2103 struct class_interface *class_intf;
2104 int error = -EINVAL;
2105 struct kobject *glue_dir = NULL;
2106
2107 dev = get_device(dev);
2108 if (!dev)
2109 goto done;
2110
2111 if (!dev->p) {
2112 error = device_private_init(dev);
2113 if (error)
2114 goto done;
2115 }
2116
2117 /*
2118 * for statically allocated devices, which should all be converted
2119 * some day, we need to initialize the name. We prevent reading back
2120 * the name, and force the use of dev_name()
2121 */
2122 if (dev->init_name) {
2123 dev_set_name(dev, "%s", dev->init_name);
2124 dev->init_name = NULL;
2125 }
2126
2127 /* subsystems can specify simple device enumeration */
2128 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
2129 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
2130
2131 if (!dev_name(dev)) {
2132 error = -EINVAL;
2133 goto name_error;
2134 }
2135
2136 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2137
2138 parent = get_device(dev->parent);
2139 kobj = get_device_parent(dev, parent);
2140 if (IS_ERR(kobj)) {
2141 error = PTR_ERR(kobj);
2142 goto parent_error;
2143 }
2144 if (kobj)
2145 dev->kobj.parent = kobj;
2146
2147 /* use parent numa_node */
2148 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
2149 set_dev_node(dev, dev_to_node(parent));
2150
2151 /* first, register with generic layer. */
2152 /* we require the name to be set before, and pass NULL */
2153 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
2154 if (error) {
2155 glue_dir = get_glue_dir(dev);
2156 goto Error;
2157 }
2158
2159 /* notify platform of device entry */
2160 error = device_platform_notify(dev, KOBJ_ADD);
2161 if (error)
2162 goto platform_error;
2163
2164 error = device_create_file(dev, &dev_attr_uevent);
2165 if (error)
2166 goto attrError;
2167
2168 error = device_add_class_symlinks(dev);
2169 if (error)
2170 goto SymlinkError;
2171 error = device_add_attrs(dev);
2172 if (error)
2173 goto AttrsError;
2174 error = bus_add_device(dev);
2175 if (error)
2176 goto BusError;
2177 error = dpm_sysfs_add(dev);
2178 if (error)
2179 goto DPMError;
2180 device_pm_add(dev);
2181
2182 if (MAJOR(dev->devt)) {
2183 error = device_create_file(dev, &dev_attr_dev);
2184 if (error)
2185 goto DevAttrError;
2186
2187 error = device_create_sys_dev_entry(dev);
2188 if (error)
2189 goto SysEntryError;
2190
2191 devtmpfs_create_node(dev);
2192 }
2193
2194 /* Notify clients of device addition. This call must come
2195 * after dpm_sysfs_add() and before kobject_uevent().
2196 */
2197 if (dev->bus)
2198 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
2199 BUS_NOTIFY_ADD_DEVICE, dev);
2200
2201 kobject_uevent(&dev->kobj, KOBJ_ADD);
2202 bus_probe_device(dev);
2203 if (parent)
2204 klist_add_tail(&dev->p->knode_parent,
2205 &parent->p->klist_children);
2206
2207 if (dev->class) {
2208 mutex_lock(&dev->class->p->mutex);
2209 /* tie the class to the device */
2210 klist_add_tail(&dev->p->knode_class,
2211 &dev->class->p->klist_devices);
2212
2213 /* notify any interfaces that the device is here */
2214 list_for_each_entry(class_intf,
2215 &dev->class->p->interfaces, node)
2216 if (class_intf->add_dev)
2217 class_intf->add_dev(dev, class_intf);
2218 mutex_unlock(&dev->class->p->mutex);
2219 }
2220done:
2221 put_device(dev);
2222 return error;
2223 SysEntryError:
2224 if (MAJOR(dev->devt))
2225 device_remove_file(dev, &dev_attr_dev);
2226 DevAttrError:
2227 device_pm_remove(dev);
2228 dpm_sysfs_remove(dev);
2229 DPMError:
2230 bus_remove_device(dev);
2231 BusError:
2232 device_remove_attrs(dev);
2233 AttrsError:
2234 device_remove_class_symlinks(dev);
2235 SymlinkError:
2236 device_remove_file(dev, &dev_attr_uevent);
2237 attrError:
2238 device_platform_notify(dev, KOBJ_REMOVE);
2239platform_error:
2240 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
2241 glue_dir = get_glue_dir(dev);
2242 kobject_del(&dev->kobj);
2243 Error:
2244 cleanup_glue_dir(dev, glue_dir);
2245parent_error:
2246 put_device(parent);
2247name_error:
2248 kfree(dev->p);
2249 dev->p = NULL;
2250 goto done;
2251}
2252EXPORT_SYMBOL_GPL(device_add);
2253
2254/**
2255 * device_register - register a device with the system.
2256 * @dev: pointer to the device structure
2257 *
2258 * This happens in two clean steps - initialize the device
2259 * and add it to the system. The two steps can be called
2260 * separately, but this is the easiest and most common.
2261 * I.e. you should only call the two helpers separately if
2262 * have a clearly defined need to use and refcount the device
2263 * before it is added to the hierarchy.
2264 *
2265 * For more information, see the kerneldoc for device_initialize()
2266 * and device_add().
2267 *
2268 * NOTE: _Never_ directly free @dev after calling this function, even
2269 * if it returned an error! Always use put_device() to give up the
2270 * reference initialized in this function instead.
2271 */
2272int device_register(struct device *dev)
2273{
2274 device_initialize(dev);
2275 return device_add(dev);
2276}
2277EXPORT_SYMBOL_GPL(device_register);
2278
2279/**
2280 * get_device - increment reference count for device.
2281 * @dev: device.
2282 *
2283 * This simply forwards the call to kobject_get(), though
2284 * we do take care to provide for the case that we get a NULL
2285 * pointer passed in.
2286 */
2287struct device *get_device(struct device *dev)
2288{
2289 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
2290}
2291EXPORT_SYMBOL_GPL(get_device);
2292
2293/**
2294 * put_device - decrement reference count.
2295 * @dev: device in question.
2296 */
2297void put_device(struct device *dev)
2298{
2299 /* might_sleep(); */
2300 if (dev)
2301 kobject_put(&dev->kobj);
2302}
2303EXPORT_SYMBOL_GPL(put_device);
2304
2305bool kill_device(struct device *dev)
2306{
2307 /*
2308 * Require the device lock and set the "dead" flag to guarantee that
2309 * the update behavior is consistent with the other bitfields near
2310 * it and that we cannot have an asynchronous probe routine trying
2311 * to run while we are tearing out the bus/class/sysfs from
2312 * underneath the device.
2313 */
2314 lockdep_assert_held(&dev->mutex);
2315
2316 if (dev->p->dead)
2317 return false;
2318 dev->p->dead = true;
2319 return true;
2320}
2321EXPORT_SYMBOL_GPL(kill_device);
2322
2323/**
2324 * device_del - delete device from system.
2325 * @dev: device.
2326 *
2327 * This is the first part of the device unregistration
2328 * sequence. This removes the device from the lists we control
2329 * from here, has it removed from the other driver model
2330 * subsystems it was added to in device_add(), and removes it
2331 * from the kobject hierarchy.
2332 *
2333 * NOTE: this should be called manually _iff_ device_add() was
2334 * also called manually.
2335 */
2336void device_del(struct device *dev)
2337{
2338 struct device *parent = dev->parent;
2339 struct kobject *glue_dir = NULL;
2340 struct class_interface *class_intf;
2341
2342 device_lock(dev);
2343 kill_device(dev);
2344 device_unlock(dev);
2345
2346 /* Notify clients of device removal. This call must come
2347 * before dpm_sysfs_remove().
2348 */
2349 if (dev->bus)
2350 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
2351 BUS_NOTIFY_DEL_DEVICE, dev);
2352
2353 dpm_sysfs_remove(dev);
2354 if (parent)
2355 klist_del(&dev->p->knode_parent);
2356 if (MAJOR(dev->devt)) {
2357 devtmpfs_delete_node(dev);
2358 device_remove_sys_dev_entry(dev);
2359 device_remove_file(dev, &dev_attr_dev);
2360 }
2361 if (dev->class) {
2362 device_remove_class_symlinks(dev);
2363
2364 mutex_lock(&dev->class->p->mutex);
2365 /* notify any interfaces that the device is now gone */
2366 list_for_each_entry(class_intf,
2367 &dev->class->p->interfaces, node)
2368 if (class_intf->remove_dev)
2369 class_intf->remove_dev(dev, class_intf);
2370 /* remove the device from the class list */
2371 klist_del(&dev->p->knode_class);
2372 mutex_unlock(&dev->class->p->mutex);
2373 }
2374 device_remove_file(dev, &dev_attr_uevent);
2375 device_remove_attrs(dev);
2376 bus_remove_device(dev);
2377 device_pm_remove(dev);
2378 driver_deferred_probe_del(dev);
2379 device_platform_notify(dev, KOBJ_REMOVE);
2380 device_remove_properties(dev);
2381 device_links_purge(dev);
2382
2383 if (dev->bus)
2384 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
2385 BUS_NOTIFY_REMOVED_DEVICE, dev);
2386 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
2387 glue_dir = get_glue_dir(dev);
2388 kobject_del(&dev->kobj);
2389 cleanup_glue_dir(dev, glue_dir);
2390 put_device(parent);
2391}
2392EXPORT_SYMBOL_GPL(device_del);
2393
2394/**
2395 * device_unregister - unregister device from system.
2396 * @dev: device going away.
2397 *
2398 * We do this in two parts, like we do device_register(). First,
2399 * we remove it from all the subsystems with device_del(), then
2400 * we decrement the reference count via put_device(). If that
2401 * is the final reference count, the device will be cleaned up
2402 * via device_release() above. Otherwise, the structure will
2403 * stick around until the final reference to the device is dropped.
2404 */
2405void device_unregister(struct device *dev)
2406{
2407 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2408 device_del(dev);
2409 put_device(dev);
2410}
2411EXPORT_SYMBOL_GPL(device_unregister);
2412
2413static struct device *prev_device(struct klist_iter *i)
2414{
2415 struct klist_node *n = klist_prev(i);
2416 struct device *dev = NULL;
2417 struct device_private *p;
2418
2419 if (n) {
2420 p = to_device_private_parent(n);
2421 dev = p->device;
2422 }
2423 return dev;
2424}
2425
2426static struct device *next_device(struct klist_iter *i)
2427{
2428 struct klist_node *n = klist_next(i);
2429 struct device *dev = NULL;
2430 struct device_private *p;
2431
2432 if (n) {
2433 p = to_device_private_parent(n);
2434 dev = p->device;
2435 }
2436 return dev;
2437}
2438
2439/**
2440 * device_get_devnode - path of device node file
2441 * @dev: device
2442 * @mode: returned file access mode
2443 * @uid: returned file owner
2444 * @gid: returned file group
2445 * @tmp: possibly allocated string
2446 *
2447 * Return the relative path of a possible device node.
2448 * Non-default names may need to allocate a memory to compose
2449 * a name. This memory is returned in tmp and needs to be
2450 * freed by the caller.
2451 */
2452const char *device_get_devnode(struct device *dev,
2453 umode_t *mode, kuid_t *uid, kgid_t *gid,
2454 const char **tmp)
2455{
2456 char *s;
2457
2458 *tmp = NULL;
2459
2460 /* the device type may provide a specific name */
2461 if (dev->type && dev->type->devnode)
2462 *tmp = dev->type->devnode(dev, mode, uid, gid);
2463 if (*tmp)
2464 return *tmp;
2465
2466 /* the class may provide a specific name */
2467 if (dev->class && dev->class->devnode)
2468 *tmp = dev->class->devnode(dev, mode);
2469 if (*tmp)
2470 return *tmp;
2471
2472 /* return name without allocation, tmp == NULL */
2473 if (strchr(dev_name(dev), '!') == NULL)
2474 return dev_name(dev);
2475
2476 /* replace '!' in the name with '/' */
2477 s = kstrdup(dev_name(dev), GFP_KERNEL);
2478 if (!s)
2479 return NULL;
2480 strreplace(s, '!', '/');
2481 return *tmp = s;
2482}
2483
2484/**
2485 * device_for_each_child - device child iterator.
2486 * @parent: parent struct device.
2487 * @fn: function to be called for each device.
2488 * @data: data for the callback.
2489 *
2490 * Iterate over @parent's child devices, and call @fn for each,
2491 * passing it @data.
2492 *
2493 * We check the return of @fn each time. If it returns anything
2494 * other than 0, we break out and return that value.
2495 */
2496int device_for_each_child(struct device *parent, void *data,
2497 int (*fn)(struct device *dev, void *data))
2498{
2499 struct klist_iter i;
2500 struct device *child;
2501 int error = 0;
2502
2503 if (!parent->p)
2504 return 0;
2505
2506 klist_iter_init(&parent->p->klist_children, &i);
2507 while (!error && (child = next_device(&i)))
2508 error = fn(child, data);
2509 klist_iter_exit(&i);
2510 return error;
2511}
2512EXPORT_SYMBOL_GPL(device_for_each_child);
2513
2514/**
2515 * device_for_each_child_reverse - device child iterator in reversed order.
2516 * @parent: parent struct device.
2517 * @fn: function to be called for each device.
2518 * @data: data for the callback.
2519 *
2520 * Iterate over @parent's child devices, and call @fn for each,
2521 * passing it @data.
2522 *
2523 * We check the return of @fn each time. If it returns anything
2524 * other than 0, we break out and return that value.
2525 */
2526int device_for_each_child_reverse(struct device *parent, void *data,
2527 int (*fn)(struct device *dev, void *data))
2528{
2529 struct klist_iter i;
2530 struct device *child;
2531 int error = 0;
2532
2533 if (!parent->p)
2534 return 0;
2535
2536 klist_iter_init(&parent->p->klist_children, &i);
2537 while ((child = prev_device(&i)) && !error)
2538 error = fn(child, data);
2539 klist_iter_exit(&i);
2540 return error;
2541}
2542EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
2543
2544/**
2545 * device_find_child - device iterator for locating a particular device.
2546 * @parent: parent struct device
2547 * @match: Callback function to check device
2548 * @data: Data to pass to match function
2549 *
2550 * This is similar to the device_for_each_child() function above, but it
2551 * returns a reference to a device that is 'found' for later use, as
2552 * determined by the @match callback.
2553 *
2554 * The callback should return 0 if the device doesn't match and non-zero
2555 * if it does. If the callback returns non-zero and a reference to the
2556 * current device can be obtained, this function will return to the caller
2557 * and not iterate over any more devices.
2558 *
2559 * NOTE: you will need to drop the reference with put_device() after use.
2560 */
2561struct device *device_find_child(struct device *parent, void *data,
2562 int (*match)(struct device *dev, void *data))
2563{
2564 struct klist_iter i;
2565 struct device *child;
2566
2567 if (!parent)
2568 return NULL;
2569
2570 klist_iter_init(&parent->p->klist_children, &i);
2571 while ((child = next_device(&i)))
2572 if (match(child, data) && get_device(child))
2573 break;
2574 klist_iter_exit(&i);
2575 return child;
2576}
2577EXPORT_SYMBOL_GPL(device_find_child);
2578
2579/**
2580 * device_find_child_by_name - device iterator for locating a child device.
2581 * @parent: parent struct device
2582 * @name: name of the child device
2583 *
2584 * This is similar to the device_find_child() function above, but it
2585 * returns a reference to a device that has the name @name.
2586 *
2587 * NOTE: you will need to drop the reference with put_device() after use.
2588 */
2589struct device *device_find_child_by_name(struct device *parent,
2590 const char *name)
2591{
2592 struct klist_iter i;
2593 struct device *child;
2594
2595 if (!parent)
2596 return NULL;
2597
2598 klist_iter_init(&parent->p->klist_children, &i);
2599 while ((child = next_device(&i)))
2600 if (!strcmp(dev_name(child), name) && get_device(child))
2601 break;
2602 klist_iter_exit(&i);
2603 return child;
2604}
2605EXPORT_SYMBOL_GPL(device_find_child_by_name);
2606
2607int __init devices_init(void)
2608{
2609 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
2610 if (!devices_kset)
2611 return -ENOMEM;
2612 dev_kobj = kobject_create_and_add("dev", NULL);
2613 if (!dev_kobj)
2614 goto dev_kobj_err;
2615 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
2616 if (!sysfs_dev_block_kobj)
2617 goto block_kobj_err;
2618 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
2619 if (!sysfs_dev_char_kobj)
2620 goto char_kobj_err;
2621
2622 return 0;
2623
2624 char_kobj_err:
2625 kobject_put(sysfs_dev_block_kobj);
2626 block_kobj_err:
2627 kobject_put(dev_kobj);
2628 dev_kobj_err:
2629 kset_unregister(devices_kset);
2630 return -ENOMEM;
2631}
2632
2633static int device_check_offline(struct device *dev, void *not_used)
2634{
2635 int ret;
2636
2637 ret = device_for_each_child(dev, NULL, device_check_offline);
2638 if (ret)
2639 return ret;
2640
2641 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
2642}
2643
2644/**
2645 * device_offline - Prepare the device for hot-removal.
2646 * @dev: Device to be put offline.
2647 *
2648 * Execute the device bus type's .offline() callback, if present, to prepare
2649 * the device for a subsequent hot-removal. If that succeeds, the device must
2650 * not be used until either it is removed or its bus type's .online() callback
2651 * is executed.
2652 *
2653 * Call under device_hotplug_lock.
2654 */
2655int device_offline(struct device *dev)
2656{
2657 int ret;
2658
2659 if (dev->offline_disabled)
2660 return -EPERM;
2661
2662 ret = device_for_each_child(dev, NULL, device_check_offline);
2663 if (ret)
2664 return ret;
2665
2666 device_lock(dev);
2667 if (device_supports_offline(dev)) {
2668 if (dev->offline) {
2669 ret = 1;
2670 } else {
2671 ret = dev->bus->offline(dev);
2672 if (!ret) {
2673 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2674 dev->offline = true;
2675 }
2676 }
2677 }
2678 device_unlock(dev);
2679
2680 return ret;
2681}
2682
2683/**
2684 * device_online - Put the device back online after successful device_offline().
2685 * @dev: Device to be put back online.
2686 *
2687 * If device_offline() has been successfully executed for @dev, but the device
2688 * has not been removed subsequently, execute its bus type's .online() callback
2689 * to indicate that the device can be used again.
2690 *
2691 * Call under device_hotplug_lock.
2692 */
2693int device_online(struct device *dev)
2694{
2695 int ret = 0;
2696
2697 device_lock(dev);
2698 if (device_supports_offline(dev)) {
2699 if (dev->offline) {
2700 ret = dev->bus->online(dev);
2701 if (!ret) {
2702 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2703 dev->offline = false;
2704 }
2705 } else {
2706 ret = 1;
2707 }
2708 }
2709 device_unlock(dev);
2710
2711 return ret;
2712}
2713
2714struct root_device {
2715 struct device dev;
2716 struct module *owner;
2717};
2718
2719static inline struct root_device *to_root_device(struct device *d)
2720{
2721 return container_of(d, struct root_device, dev);
2722}
2723
2724static void root_device_release(struct device *dev)
2725{
2726 kfree(to_root_device(dev));
2727}
2728
2729/**
2730 * __root_device_register - allocate and register a root device
2731 * @name: root device name
2732 * @owner: owner module of the root device, usually THIS_MODULE
2733 *
2734 * This function allocates a root device and registers it
2735 * using device_register(). In order to free the returned
2736 * device, use root_device_unregister().
2737 *
2738 * Root devices are dummy devices which allow other devices
2739 * to be grouped under /sys/devices. Use this function to
2740 * allocate a root device and then use it as the parent of
2741 * any device which should appear under /sys/devices/{name}
2742 *
2743 * The /sys/devices/{name} directory will also contain a
2744 * 'module' symlink which points to the @owner directory
2745 * in sysfs.
2746 *
2747 * Returns &struct device pointer on success, or ERR_PTR() on error.
2748 *
2749 * Note: You probably want to use root_device_register().
2750 */
2751struct device *__root_device_register(const char *name, struct module *owner)
2752{
2753 struct root_device *root;
2754 int err = -ENOMEM;
2755
2756 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
2757 if (!root)
2758 return ERR_PTR(err);
2759
2760 err = dev_set_name(&root->dev, "%s", name);
2761 if (err) {
2762 kfree(root);
2763 return ERR_PTR(err);
2764 }
2765
2766 root->dev.release = root_device_release;
2767
2768 err = device_register(&root->dev);
2769 if (err) {
2770 put_device(&root->dev);
2771 return ERR_PTR(err);
2772 }
2773
2774#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2775 if (owner) {
2776 struct module_kobject *mk = &owner->mkobj;
2777
2778 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
2779 if (err) {
2780 device_unregister(&root->dev);
2781 return ERR_PTR(err);
2782 }
2783 root->owner = owner;
2784 }
2785#endif
2786
2787 return &root->dev;
2788}
2789EXPORT_SYMBOL_GPL(__root_device_register);
2790
2791/**
2792 * root_device_unregister - unregister and free a root device
2793 * @dev: device going away
2794 *
2795 * This function unregisters and cleans up a device that was created by
2796 * root_device_register().
2797 */
2798void root_device_unregister(struct device *dev)
2799{
2800 struct root_device *root = to_root_device(dev);
2801
2802 if (root->owner)
2803 sysfs_remove_link(&root->dev.kobj, "module");
2804
2805 device_unregister(dev);
2806}
2807EXPORT_SYMBOL_GPL(root_device_unregister);
2808
2809
2810static void device_create_release(struct device *dev)
2811{
2812 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2813 kfree(dev);
2814}
2815
2816static __printf(6, 0) struct device *
2817device_create_groups_vargs(struct class *class, struct device *parent,
2818 dev_t devt, void *drvdata,
2819 const struct attribute_group **groups,
2820 const char *fmt, va_list args)
2821{
2822 struct device *dev = NULL;
2823 int retval = -ENODEV;
2824
2825 if (class == NULL || IS_ERR(class))
2826 goto error;
2827
2828 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2829 if (!dev) {
2830 retval = -ENOMEM;
2831 goto error;
2832 }
2833
2834 device_initialize(dev);
2835 dev->devt = devt;
2836 dev->class = class;
2837 dev->parent = parent;
2838 dev->groups = groups;
2839 dev->release = device_create_release;
2840 dev_set_drvdata(dev, drvdata);
2841
2842 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
2843 if (retval)
2844 goto error;
2845
2846 retval = device_add(dev);
2847 if (retval)
2848 goto error;
2849
2850 return dev;
2851
2852error:
2853 put_device(dev);
2854 return ERR_PTR(retval);
2855}
2856
2857/**
2858 * device_create_vargs - creates a device and registers it with sysfs
2859 * @class: pointer to the struct class that this device should be registered to
2860 * @parent: pointer to the parent struct device of this new device, if any
2861 * @devt: the dev_t for the char device to be added
2862 * @drvdata: the data to be added to the device for callbacks
2863 * @fmt: string for the device's name
2864 * @args: va_list for the device's name
2865 *
2866 * This function can be used by char device classes. A struct device
2867 * will be created in sysfs, registered to the specified class.
2868 *
2869 * A "dev" file will be created, showing the dev_t for the device, if
2870 * the dev_t is not 0,0.
2871 * If a pointer to a parent struct device is passed in, the newly created
2872 * struct device will be a child of that device in sysfs.
2873 * The pointer to the struct device will be returned from the call.
2874 * Any further sysfs files that might be required can be created using this
2875 * pointer.
2876 *
2877 * Returns &struct device pointer on success, or ERR_PTR() on error.
2878 *
2879 * Note: the struct class passed to this function must have previously
2880 * been created with a call to class_create().
2881 */
2882struct device *device_create_vargs(struct class *class, struct device *parent,
2883 dev_t devt, void *drvdata, const char *fmt,
2884 va_list args)
2885{
2886 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
2887 fmt, args);
2888}
2889EXPORT_SYMBOL_GPL(device_create_vargs);
2890
2891/**
2892 * device_create - creates a device and registers it with sysfs
2893 * @class: pointer to the struct class that this device should be registered to
2894 * @parent: pointer to the parent struct device of this new device, if any
2895 * @devt: the dev_t for the char device to be added
2896 * @drvdata: the data to be added to the device for callbacks
2897 * @fmt: string for the device's name
2898 *
2899 * This function can be used by char device classes. A struct device
2900 * will be created in sysfs, registered to the specified class.
2901 *
2902 * A "dev" file will be created, showing the dev_t for the device, if
2903 * the dev_t is not 0,0.
2904 * If a pointer to a parent struct device is passed in, the newly created
2905 * struct device will be a child of that device in sysfs.
2906 * The pointer to the struct device will be returned from the call.
2907 * Any further sysfs files that might be required can be created using this
2908 * pointer.
2909 *
2910 * Returns &struct device pointer on success, or ERR_PTR() on error.
2911 *
2912 * Note: the struct class passed to this function must have previously
2913 * been created with a call to class_create().
2914 */
2915struct device *device_create(struct class *class, struct device *parent,
2916 dev_t devt, void *drvdata, const char *fmt, ...)
2917{
2918 va_list vargs;
2919 struct device *dev;
2920
2921 va_start(vargs, fmt);
2922 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
2923 va_end(vargs);
2924 return dev;
2925}
2926EXPORT_SYMBOL_GPL(device_create);
2927
2928/**
2929 * device_create_with_groups - creates a device and registers it with sysfs
2930 * @class: pointer to the struct class that this device should be registered to
2931 * @parent: pointer to the parent struct device of this new device, if any
2932 * @devt: the dev_t for the char device to be added
2933 * @drvdata: the data to be added to the device for callbacks
2934 * @groups: NULL-terminated list of attribute groups to be created
2935 * @fmt: string for the device's name
2936 *
2937 * This function can be used by char device classes. A struct device
2938 * will be created in sysfs, registered to the specified class.
2939 * Additional attributes specified in the groups parameter will also
2940 * be created automatically.
2941 *
2942 * A "dev" file will be created, showing the dev_t for the device, if
2943 * the dev_t is not 0,0.
2944 * If a pointer to a parent struct device is passed in, the newly created
2945 * struct device will be a child of that device in sysfs.
2946 * The pointer to the struct device will be returned from the call.
2947 * Any further sysfs files that might be required can be created using this
2948 * pointer.
2949 *
2950 * Returns &struct device pointer on success, or ERR_PTR() on error.
2951 *
2952 * Note: the struct class passed to this function must have previously
2953 * been created with a call to class_create().
2954 */
2955struct device *device_create_with_groups(struct class *class,
2956 struct device *parent, dev_t devt,
2957 void *drvdata,
2958 const struct attribute_group **groups,
2959 const char *fmt, ...)
2960{
2961 va_list vargs;
2962 struct device *dev;
2963
2964 va_start(vargs, fmt);
2965 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
2966 fmt, vargs);
2967 va_end(vargs);
2968 return dev;
2969}
2970EXPORT_SYMBOL_GPL(device_create_with_groups);
2971
2972/**
2973 * device_destroy - removes a device that was created with device_create()
2974 * @class: pointer to the struct class that this device was registered with
2975 * @devt: the dev_t of the device that was previously registered
2976 *
2977 * This call unregisters and cleans up a device that was created with a
2978 * call to device_create().
2979 */
2980void device_destroy(struct class *class, dev_t devt)
2981{
2982 struct device *dev;
2983
2984 dev = class_find_device_by_devt(class, devt);
2985 if (dev) {
2986 put_device(dev);
2987 device_unregister(dev);
2988 }
2989}
2990EXPORT_SYMBOL_GPL(device_destroy);
2991
2992/**
2993 * device_rename - renames a device
2994 * @dev: the pointer to the struct device to be renamed
2995 * @new_name: the new name of the device
2996 *
2997 * It is the responsibility of the caller to provide mutual
2998 * exclusion between two different calls of device_rename
2999 * on the same device to ensure that new_name is valid and
3000 * won't conflict with other devices.
3001 *
3002 * Note: Don't call this function. Currently, the networking layer calls this
3003 * function, but that will change. The following text from Kay Sievers offers
3004 * some insight:
3005 *
3006 * Renaming devices is racy at many levels, symlinks and other stuff are not
3007 * replaced atomically, and you get a "move" uevent, but it's not easy to
3008 * connect the event to the old and new device. Device nodes are not renamed at
3009 * all, there isn't even support for that in the kernel now.
3010 *
3011 * In the meantime, during renaming, your target name might be taken by another
3012 * driver, creating conflicts. Or the old name is taken directly after you
3013 * renamed it -- then you get events for the same DEVPATH, before you even see
3014 * the "move" event. It's just a mess, and nothing new should ever rely on
3015 * kernel device renaming. Besides that, it's not even implemented now for
3016 * other things than (driver-core wise very simple) network devices.
3017 *
3018 * We are currently about to change network renaming in udev to completely
3019 * disallow renaming of devices in the same namespace as the kernel uses,
3020 * because we can't solve the problems properly, that arise with swapping names
3021 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
3022 * be allowed to some other name than eth[0-9]*, for the aforementioned
3023 * reasons.
3024 *
3025 * Make up a "real" name in the driver before you register anything, or add
3026 * some other attributes for userspace to find the device, or use udev to add
3027 * symlinks -- but never rename kernel devices later, it's a complete mess. We
3028 * don't even want to get into that and try to implement the missing pieces in
3029 * the core. We really have other pieces to fix in the driver core mess. :)
3030 */
3031int device_rename(struct device *dev, const char *new_name)
3032{
3033 struct kobject *kobj = &dev->kobj;
3034 char *old_device_name = NULL;
3035 int error;
3036
3037 dev = get_device(dev);
3038 if (!dev)
3039 return -EINVAL;
3040
3041 dev_dbg(dev, "renaming to %s\n", new_name);
3042
3043 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
3044 if (!old_device_name) {
3045 error = -ENOMEM;
3046 goto out;
3047 }
3048
3049 if (dev->class) {
3050 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
3051 kobj, old_device_name,
3052 new_name, kobject_namespace(kobj));
3053 if (error)
3054 goto out;
3055 }
3056
3057 error = kobject_rename(kobj, new_name);
3058 if (error)
3059 goto out;
3060
3061out:
3062 put_device(dev);
3063
3064 kfree(old_device_name);
3065
3066 return error;
3067}
3068EXPORT_SYMBOL_GPL(device_rename);
3069
3070static int device_move_class_links(struct device *dev,
3071 struct device *old_parent,
3072 struct device *new_parent)
3073{
3074 int error = 0;
3075
3076 if (old_parent)
3077 sysfs_remove_link(&dev->kobj, "device");
3078 if (new_parent)
3079 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
3080 "device");
3081 return error;
3082}
3083
3084/**
3085 * device_move - moves a device to a new parent
3086 * @dev: the pointer to the struct device to be moved
3087 * @new_parent: the new parent of the device (can be NULL)
3088 * @dpm_order: how to reorder the dpm_list
3089 */
3090int device_move(struct device *dev, struct device *new_parent,
3091 enum dpm_order dpm_order)
3092{
3093 int error;
3094 struct device *old_parent;
3095 struct kobject *new_parent_kobj;
3096
3097 dev = get_device(dev);
3098 if (!dev)
3099 return -EINVAL;
3100
3101 device_pm_lock();
3102 new_parent = get_device(new_parent);
3103 new_parent_kobj = get_device_parent(dev, new_parent);
3104 if (IS_ERR(new_parent_kobj)) {
3105 error = PTR_ERR(new_parent_kobj);
3106 put_device(new_parent);
3107 goto out;
3108 }
3109
3110 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
3111 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
3112 error = kobject_move(&dev->kobj, new_parent_kobj);
3113 if (error) {
3114 cleanup_glue_dir(dev, new_parent_kobj);
3115 put_device(new_parent);
3116 goto out;
3117 }
3118 old_parent = dev->parent;
3119 dev->parent = new_parent;
3120 if (old_parent)
3121 klist_remove(&dev->p->knode_parent);
3122 if (new_parent) {
3123 klist_add_tail(&dev->p->knode_parent,
3124 &new_parent->p->klist_children);
3125 set_dev_node(dev, dev_to_node(new_parent));
3126 }
3127
3128 if (dev->class) {
3129 error = device_move_class_links(dev, old_parent, new_parent);
3130 if (error) {
3131 /* We ignore errors on cleanup since we're hosed anyway... */
3132 device_move_class_links(dev, new_parent, old_parent);
3133 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
3134 if (new_parent)
3135 klist_remove(&dev->p->knode_parent);
3136 dev->parent = old_parent;
3137 if (old_parent) {
3138 klist_add_tail(&dev->p->knode_parent,
3139 &old_parent->p->klist_children);
3140 set_dev_node(dev, dev_to_node(old_parent));
3141 }
3142 }
3143 cleanup_glue_dir(dev, new_parent_kobj);
3144 put_device(new_parent);
3145 goto out;
3146 }
3147 }
3148 switch (dpm_order) {
3149 case DPM_ORDER_NONE:
3150 break;
3151 case DPM_ORDER_DEV_AFTER_PARENT:
3152 device_pm_move_after(dev, new_parent);
3153 devices_kset_move_after(dev, new_parent);
3154 break;
3155 case DPM_ORDER_PARENT_BEFORE_DEV:
3156 device_pm_move_before(new_parent, dev);
3157 devices_kset_move_before(new_parent, dev);
3158 break;
3159 case DPM_ORDER_DEV_LAST:
3160 device_pm_move_last(dev);
3161 devices_kset_move_last(dev);
3162 break;
3163 }
3164
3165 put_device(old_parent);
3166out:
3167 device_pm_unlock();
3168 put_device(dev);
3169 return error;
3170}
3171EXPORT_SYMBOL_GPL(device_move);
3172
3173/**
3174 * device_shutdown - call ->shutdown() on each device to shutdown.
3175 */
3176void device_shutdown(void)
3177{
3178 struct device *dev, *parent;
3179
3180 wait_for_device_probe();
3181 device_block_probing();
3182
3183 cpufreq_suspend();
3184
3185 spin_lock(&devices_kset->list_lock);
3186 /*
3187 * Walk the devices list backward, shutting down each in turn.
3188 * Beware that device unplug events may also start pulling
3189 * devices offline, even as the system is shutting down.
3190 */
3191 while (!list_empty(&devices_kset->list)) {
3192 dev = list_entry(devices_kset->list.prev, struct device,
3193 kobj.entry);
3194
3195 /*
3196 * hold reference count of device's parent to
3197 * prevent it from being freed because parent's
3198 * lock is to be held
3199 */
3200 parent = get_device(dev->parent);
3201 get_device(dev);
3202 /*
3203 * Make sure the device is off the kset list, in the
3204 * event that dev->*->shutdown() doesn't remove it.
3205 */
3206 list_del_init(&dev->kobj.entry);
3207 spin_unlock(&devices_kset->list_lock);
3208
3209 /* hold lock to avoid race with probe/release */
3210 if (parent)
3211 device_lock(parent);
3212 device_lock(dev);
3213
3214 /* Don't allow any more runtime suspends */
3215 pm_runtime_get_noresume(dev);
3216 pm_runtime_barrier(dev);
3217
3218 if (dev->class && dev->class->shutdown_pre) {
3219 if (initcall_debug)
3220 dev_info(dev, "shutdown_pre\n");
3221 dev->class->shutdown_pre(dev);
3222 }
3223 if (dev->bus && dev->bus->shutdown) {
3224 if (initcall_debug)
3225 dev_info(dev, "shutdown\n");
3226 dev->bus->shutdown(dev);
3227 } else if (dev->driver && dev->driver->shutdown) {
3228 if (initcall_debug)
3229 dev_info(dev, "shutdown\n");
3230 dev->driver->shutdown(dev);
3231 }
3232
3233 device_unlock(dev);
3234 if (parent)
3235 device_unlock(parent);
3236
3237 put_device(dev);
3238 put_device(parent);
3239
3240 spin_lock(&devices_kset->list_lock);
3241 }
3242 spin_unlock(&devices_kset->list_lock);
3243}
3244
3245/*
3246 * Device logging functions
3247 */
3248
3249#ifdef CONFIG_PRINTK
3250static int
3251create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
3252{
3253 const char *subsys;
3254 size_t pos = 0;
3255
3256 if (dev->class)
3257 subsys = dev->class->name;
3258 else if (dev->bus)
3259 subsys = dev->bus->name;
3260 else
3261 return 0;
3262
3263 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
3264 if (pos >= hdrlen)
3265 goto overflow;
3266
3267 /*
3268 * Add device identifier DEVICE=:
3269 * b12:8 block dev_t
3270 * c127:3 char dev_t
3271 * n8 netdev ifindex
3272 * +sound:card0 subsystem:devname
3273 */
3274 if (MAJOR(dev->devt)) {
3275 char c;
3276
3277 if (strcmp(subsys, "block") == 0)
3278 c = 'b';
3279 else
3280 c = 'c';
3281 pos++;
3282 pos += snprintf(hdr + pos, hdrlen - pos,
3283 "DEVICE=%c%u:%u",
3284 c, MAJOR(dev->devt), MINOR(dev->devt));
3285 } else if (strcmp(subsys, "net") == 0) {
3286 struct net_device *net = to_net_dev(dev);
3287
3288 pos++;
3289 pos += snprintf(hdr + pos, hdrlen - pos,
3290 "DEVICE=n%u", net->ifindex);
3291 } else {
3292 pos++;
3293 pos += snprintf(hdr + pos, hdrlen - pos,
3294 "DEVICE=+%s:%s", subsys, dev_name(dev));
3295 }
3296
3297 if (pos >= hdrlen)
3298 goto overflow;
3299
3300 return pos;
3301
3302overflow:
3303 dev_WARN(dev, "device/subsystem name too long");
3304 return 0;
3305}
3306
3307int dev_vprintk_emit(int level, const struct device *dev,
3308 const char *fmt, va_list args)
3309{
3310 char hdr[128];
3311 size_t hdrlen;
3312
3313 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
3314
3315 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
3316}
3317EXPORT_SYMBOL(dev_vprintk_emit);
3318
3319int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
3320{
3321 va_list args;
3322 int r;
3323
3324 va_start(args, fmt);
3325
3326 r = dev_vprintk_emit(level, dev, fmt, args);
3327
3328 va_end(args);
3329
3330 return r;
3331}
3332EXPORT_SYMBOL(dev_printk_emit);
3333
3334static void __dev_printk(const char *level, const struct device *dev,
3335 struct va_format *vaf)
3336{
3337 if (dev)
3338 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
3339 dev_driver_string(dev), dev_name(dev), vaf);
3340 else
3341 printk("%s(NULL device *): %pV", level, vaf);
3342}
3343
3344void dev_printk(const char *level, const struct device *dev,
3345 const char *fmt, ...)
3346{
3347 struct va_format vaf;
3348 va_list args;
3349
3350 va_start(args, fmt);
3351
3352 vaf.fmt = fmt;
3353 vaf.va = &args;
3354
3355 __dev_printk(level, dev, &vaf);
3356
3357 va_end(args);
3358}
3359EXPORT_SYMBOL(dev_printk);
3360
3361#define define_dev_printk_level(func, kern_level) \
3362void func(const struct device *dev, const char *fmt, ...) \
3363{ \
3364 struct va_format vaf; \
3365 va_list args; \
3366 \
3367 va_start(args, fmt); \
3368 \
3369 vaf.fmt = fmt; \
3370 vaf.va = &args; \
3371 \
3372 __dev_printk(kern_level, dev, &vaf); \
3373 \
3374 va_end(args); \
3375} \
3376EXPORT_SYMBOL(func);
3377
3378define_dev_printk_level(_dev_emerg, KERN_EMERG);
3379define_dev_printk_level(_dev_alert, KERN_ALERT);
3380define_dev_printk_level(_dev_crit, KERN_CRIT);
3381define_dev_printk_level(_dev_err, KERN_ERR);
3382define_dev_printk_level(_dev_warn, KERN_WARNING);
3383define_dev_printk_level(_dev_notice, KERN_NOTICE);
3384define_dev_printk_level(_dev_info, KERN_INFO);
3385
3386#endif
3387
3388static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
3389{
3390 return fwnode && !IS_ERR(fwnode->secondary);
3391}
3392
3393/**
3394 * set_primary_fwnode - Change the primary firmware node of a given device.
3395 * @dev: Device to handle.
3396 * @fwnode: New primary firmware node of the device.
3397 *
3398 * Set the device's firmware node pointer to @fwnode, but if a secondary
3399 * firmware node of the device is present, preserve it.
3400 */
3401void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
3402{
3403 if (fwnode) {
3404 struct fwnode_handle *fn = dev->fwnode;
3405
3406 if (fwnode_is_primary(fn))
3407 fn = fn->secondary;
3408
3409 if (fn) {
3410 WARN_ON(fwnode->secondary);
3411 fwnode->secondary = fn;
3412 }
3413 dev->fwnode = fwnode;
3414 } else {
3415 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
3416 dev->fwnode->secondary : NULL;
3417 }
3418}
3419EXPORT_SYMBOL_GPL(set_primary_fwnode);
3420
3421/**
3422 * set_secondary_fwnode - Change the secondary firmware node of a given device.
3423 * @dev: Device to handle.
3424 * @fwnode: New secondary firmware node of the device.
3425 *
3426 * If a primary firmware node of the device is present, set its secondary
3427 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
3428 * @fwnode.
3429 */
3430void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
3431{
3432 if (fwnode)
3433 fwnode->secondary = ERR_PTR(-ENODEV);
3434
3435 if (fwnode_is_primary(dev->fwnode))
3436 dev->fwnode->secondary = fwnode;
3437 else
3438 dev->fwnode = fwnode;
3439}
3440
3441/**
3442 * device_set_of_node_from_dev - reuse device-tree node of another device
3443 * @dev: device whose device-tree node is being set
3444 * @dev2: device whose device-tree node is being reused
3445 *
3446 * Takes another reference to the new device-tree node after first dropping
3447 * any reference held to the old node.
3448 */
3449void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
3450{
3451 of_node_put(dev->of_node);
3452 dev->of_node = of_node_get(dev2->of_node);
3453 dev->of_node_reused = true;
3454}
3455EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
3456
3457int device_match_name(struct device *dev, const void *name)
3458{
3459 return sysfs_streq(dev_name(dev), name);
3460}
3461EXPORT_SYMBOL_GPL(device_match_name);
3462
3463int device_match_of_node(struct device *dev, const void *np)
3464{
3465 return dev->of_node == np;
3466}
3467EXPORT_SYMBOL_GPL(device_match_of_node);
3468
3469int device_match_fwnode(struct device *dev, const void *fwnode)
3470{
3471 return dev_fwnode(dev) == fwnode;
3472}
3473EXPORT_SYMBOL_GPL(device_match_fwnode);
3474
3475int device_match_devt(struct device *dev, const void *pdevt)
3476{
3477 return dev->devt == *(dev_t *)pdevt;
3478}
3479EXPORT_SYMBOL_GPL(device_match_devt);
3480
3481int device_match_acpi_dev(struct device *dev, const void *adev)
3482{
3483 return ACPI_COMPANION(dev) == adev;
3484}
3485EXPORT_SYMBOL(device_match_acpi_dev);
3486
3487int device_match_any(struct device *dev, const void *unused)
3488{
3489 return 1;
3490}
3491EXPORT_SYMBOL_GPL(device_match_any);
1/*
2 * drivers/base/core.c - core driver model code (device registration, etc)
3 *
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2006 Novell, Inc.
8 *
9 * This file is released under the GPLv2
10 *
11 */
12
13#include <linux/device.h>
14#include <linux/err.h>
15#include <linux/fwnode.h>
16#include <linux/init.h>
17#include <linux/module.h>
18#include <linux/slab.h>
19#include <linux/string.h>
20#include <linux/kdev_t.h>
21#include <linux/notifier.h>
22#include <linux/of.h>
23#include <linux/of_device.h>
24#include <linux/genhd.h>
25#include <linux/kallsyms.h>
26#include <linux/mutex.h>
27#include <linux/pm_runtime.h>
28#include <linux/netdevice.h>
29#include <linux/sysfs.h>
30
31#include "base.h"
32#include "power/power.h"
33
34#ifdef CONFIG_SYSFS_DEPRECATED
35#ifdef CONFIG_SYSFS_DEPRECATED_V2
36long sysfs_deprecated = 1;
37#else
38long sysfs_deprecated = 0;
39#endif
40static int __init sysfs_deprecated_setup(char *arg)
41{
42 return kstrtol(arg, 10, &sysfs_deprecated);
43}
44early_param("sysfs.deprecated", sysfs_deprecated_setup);
45#endif
46
47int (*platform_notify)(struct device *dev) = NULL;
48int (*platform_notify_remove)(struct device *dev) = NULL;
49static struct kobject *dev_kobj;
50struct kobject *sysfs_dev_char_kobj;
51struct kobject *sysfs_dev_block_kobj;
52
53static DEFINE_MUTEX(device_hotplug_lock);
54
55void lock_device_hotplug(void)
56{
57 mutex_lock(&device_hotplug_lock);
58}
59
60void unlock_device_hotplug(void)
61{
62 mutex_unlock(&device_hotplug_lock);
63}
64
65int lock_device_hotplug_sysfs(void)
66{
67 if (mutex_trylock(&device_hotplug_lock))
68 return 0;
69
70 /* Avoid busy looping (5 ms of sleep should do). */
71 msleep(5);
72 return restart_syscall();
73}
74
75#ifdef CONFIG_BLOCK
76static inline int device_is_not_partition(struct device *dev)
77{
78 return !(dev->type == &part_type);
79}
80#else
81static inline int device_is_not_partition(struct device *dev)
82{
83 return 1;
84}
85#endif
86
87/**
88 * dev_driver_string - Return a device's driver name, if at all possible
89 * @dev: struct device to get the name of
90 *
91 * Will return the device's driver's name if it is bound to a device. If
92 * the device is not bound to a driver, it will return the name of the bus
93 * it is attached to. If it is not attached to a bus either, an empty
94 * string will be returned.
95 */
96const char *dev_driver_string(const struct device *dev)
97{
98 struct device_driver *drv;
99
100 /* dev->driver can change to NULL underneath us because of unbinding,
101 * so be careful about accessing it. dev->bus and dev->class should
102 * never change once they are set, so they don't need special care.
103 */
104 drv = ACCESS_ONCE(dev->driver);
105 return drv ? drv->name :
106 (dev->bus ? dev->bus->name :
107 (dev->class ? dev->class->name : ""));
108}
109EXPORT_SYMBOL(dev_driver_string);
110
111#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
112
113static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
114 char *buf)
115{
116 struct device_attribute *dev_attr = to_dev_attr(attr);
117 struct device *dev = kobj_to_dev(kobj);
118 ssize_t ret = -EIO;
119
120 if (dev_attr->show)
121 ret = dev_attr->show(dev, dev_attr, buf);
122 if (ret >= (ssize_t)PAGE_SIZE) {
123 print_symbol("dev_attr_show: %s returned bad count\n",
124 (unsigned long)dev_attr->show);
125 }
126 return ret;
127}
128
129static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
130 const char *buf, size_t count)
131{
132 struct device_attribute *dev_attr = to_dev_attr(attr);
133 struct device *dev = kobj_to_dev(kobj);
134 ssize_t ret = -EIO;
135
136 if (dev_attr->store)
137 ret = dev_attr->store(dev, dev_attr, buf, count);
138 return ret;
139}
140
141static const struct sysfs_ops dev_sysfs_ops = {
142 .show = dev_attr_show,
143 .store = dev_attr_store,
144};
145
146#define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
147
148ssize_t device_store_ulong(struct device *dev,
149 struct device_attribute *attr,
150 const char *buf, size_t size)
151{
152 struct dev_ext_attribute *ea = to_ext_attr(attr);
153 char *end;
154 unsigned long new = simple_strtoul(buf, &end, 0);
155 if (end == buf)
156 return -EINVAL;
157 *(unsigned long *)(ea->var) = new;
158 /* Always return full write size even if we didn't consume all */
159 return size;
160}
161EXPORT_SYMBOL_GPL(device_store_ulong);
162
163ssize_t device_show_ulong(struct device *dev,
164 struct device_attribute *attr,
165 char *buf)
166{
167 struct dev_ext_attribute *ea = to_ext_attr(attr);
168 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
169}
170EXPORT_SYMBOL_GPL(device_show_ulong);
171
172ssize_t device_store_int(struct device *dev,
173 struct device_attribute *attr,
174 const char *buf, size_t size)
175{
176 struct dev_ext_attribute *ea = to_ext_attr(attr);
177 char *end;
178 long new = simple_strtol(buf, &end, 0);
179 if (end == buf || new > INT_MAX || new < INT_MIN)
180 return -EINVAL;
181 *(int *)(ea->var) = new;
182 /* Always return full write size even if we didn't consume all */
183 return size;
184}
185EXPORT_SYMBOL_GPL(device_store_int);
186
187ssize_t device_show_int(struct device *dev,
188 struct device_attribute *attr,
189 char *buf)
190{
191 struct dev_ext_attribute *ea = to_ext_attr(attr);
192
193 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
194}
195EXPORT_SYMBOL_GPL(device_show_int);
196
197ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
198 const char *buf, size_t size)
199{
200 struct dev_ext_attribute *ea = to_ext_attr(attr);
201
202 if (strtobool(buf, ea->var) < 0)
203 return -EINVAL;
204
205 return size;
206}
207EXPORT_SYMBOL_GPL(device_store_bool);
208
209ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
210 char *buf)
211{
212 struct dev_ext_attribute *ea = to_ext_attr(attr);
213
214 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
215}
216EXPORT_SYMBOL_GPL(device_show_bool);
217
218/**
219 * device_release - free device structure.
220 * @kobj: device's kobject.
221 *
222 * This is called once the reference count for the object
223 * reaches 0. We forward the call to the device's release
224 * method, which should handle actually freeing the structure.
225 */
226static void device_release(struct kobject *kobj)
227{
228 struct device *dev = kobj_to_dev(kobj);
229 struct device_private *p = dev->p;
230
231 /*
232 * Some platform devices are driven without driver attached
233 * and managed resources may have been acquired. Make sure
234 * all resources are released.
235 *
236 * Drivers still can add resources into device after device
237 * is deleted but alive, so release devres here to avoid
238 * possible memory leak.
239 */
240 devres_release_all(dev);
241
242 if (dev->release)
243 dev->release(dev);
244 else if (dev->type && dev->type->release)
245 dev->type->release(dev);
246 else if (dev->class && dev->class->dev_release)
247 dev->class->dev_release(dev);
248 else
249 WARN(1, KERN_ERR "Device '%s' does not have a release() "
250 "function, it is broken and must be fixed.\n",
251 dev_name(dev));
252 kfree(p);
253}
254
255static const void *device_namespace(struct kobject *kobj)
256{
257 struct device *dev = kobj_to_dev(kobj);
258 const void *ns = NULL;
259
260 if (dev->class && dev->class->ns_type)
261 ns = dev->class->namespace(dev);
262
263 return ns;
264}
265
266static struct kobj_type device_ktype = {
267 .release = device_release,
268 .sysfs_ops = &dev_sysfs_ops,
269 .namespace = device_namespace,
270};
271
272
273static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
274{
275 struct kobj_type *ktype = get_ktype(kobj);
276
277 if (ktype == &device_ktype) {
278 struct device *dev = kobj_to_dev(kobj);
279 if (dev->bus)
280 return 1;
281 if (dev->class)
282 return 1;
283 }
284 return 0;
285}
286
287static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
288{
289 struct device *dev = kobj_to_dev(kobj);
290
291 if (dev->bus)
292 return dev->bus->name;
293 if (dev->class)
294 return dev->class->name;
295 return NULL;
296}
297
298static int dev_uevent(struct kset *kset, struct kobject *kobj,
299 struct kobj_uevent_env *env)
300{
301 struct device *dev = kobj_to_dev(kobj);
302 int retval = 0;
303
304 /* add device node properties if present */
305 if (MAJOR(dev->devt)) {
306 const char *tmp;
307 const char *name;
308 umode_t mode = 0;
309 kuid_t uid = GLOBAL_ROOT_UID;
310 kgid_t gid = GLOBAL_ROOT_GID;
311
312 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
313 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
314 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
315 if (name) {
316 add_uevent_var(env, "DEVNAME=%s", name);
317 if (mode)
318 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
319 if (!uid_eq(uid, GLOBAL_ROOT_UID))
320 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
321 if (!gid_eq(gid, GLOBAL_ROOT_GID))
322 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
323 kfree(tmp);
324 }
325 }
326
327 if (dev->type && dev->type->name)
328 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
329
330 if (dev->driver)
331 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
332
333 /* Add common DT information about the device */
334 of_device_uevent(dev, env);
335
336 /* have the bus specific function add its stuff */
337 if (dev->bus && dev->bus->uevent) {
338 retval = dev->bus->uevent(dev, env);
339 if (retval)
340 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
341 dev_name(dev), __func__, retval);
342 }
343
344 /* have the class specific function add its stuff */
345 if (dev->class && dev->class->dev_uevent) {
346 retval = dev->class->dev_uevent(dev, env);
347 if (retval)
348 pr_debug("device: '%s': %s: class uevent() "
349 "returned %d\n", dev_name(dev),
350 __func__, retval);
351 }
352
353 /* have the device type specific function add its stuff */
354 if (dev->type && dev->type->uevent) {
355 retval = dev->type->uevent(dev, env);
356 if (retval)
357 pr_debug("device: '%s': %s: dev_type uevent() "
358 "returned %d\n", dev_name(dev),
359 __func__, retval);
360 }
361
362 return retval;
363}
364
365static const struct kset_uevent_ops device_uevent_ops = {
366 .filter = dev_uevent_filter,
367 .name = dev_uevent_name,
368 .uevent = dev_uevent,
369};
370
371static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
372 char *buf)
373{
374 struct kobject *top_kobj;
375 struct kset *kset;
376 struct kobj_uevent_env *env = NULL;
377 int i;
378 size_t count = 0;
379 int retval;
380
381 /* search the kset, the device belongs to */
382 top_kobj = &dev->kobj;
383 while (!top_kobj->kset && top_kobj->parent)
384 top_kobj = top_kobj->parent;
385 if (!top_kobj->kset)
386 goto out;
387
388 kset = top_kobj->kset;
389 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
390 goto out;
391
392 /* respect filter */
393 if (kset->uevent_ops && kset->uevent_ops->filter)
394 if (!kset->uevent_ops->filter(kset, &dev->kobj))
395 goto out;
396
397 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
398 if (!env)
399 return -ENOMEM;
400
401 /* let the kset specific function add its keys */
402 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
403 if (retval)
404 goto out;
405
406 /* copy keys to file */
407 for (i = 0; i < env->envp_idx; i++)
408 count += sprintf(&buf[count], "%s\n", env->envp[i]);
409out:
410 kfree(env);
411 return count;
412}
413
414static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
415 const char *buf, size_t count)
416{
417 enum kobject_action action;
418
419 if (kobject_action_type(buf, count, &action) == 0)
420 kobject_uevent(&dev->kobj, action);
421 else
422 dev_err(dev, "uevent: unknown action-string\n");
423 return count;
424}
425static DEVICE_ATTR_RW(uevent);
426
427static ssize_t online_show(struct device *dev, struct device_attribute *attr,
428 char *buf)
429{
430 bool val;
431
432 device_lock(dev);
433 val = !dev->offline;
434 device_unlock(dev);
435 return sprintf(buf, "%u\n", val);
436}
437
438static ssize_t online_store(struct device *dev, struct device_attribute *attr,
439 const char *buf, size_t count)
440{
441 bool val;
442 int ret;
443
444 ret = strtobool(buf, &val);
445 if (ret < 0)
446 return ret;
447
448 ret = lock_device_hotplug_sysfs();
449 if (ret)
450 return ret;
451
452 ret = val ? device_online(dev) : device_offline(dev);
453 unlock_device_hotplug();
454 return ret < 0 ? ret : count;
455}
456static DEVICE_ATTR_RW(online);
457
458int device_add_groups(struct device *dev, const struct attribute_group **groups)
459{
460 return sysfs_create_groups(&dev->kobj, groups);
461}
462
463void device_remove_groups(struct device *dev,
464 const struct attribute_group **groups)
465{
466 sysfs_remove_groups(&dev->kobj, groups);
467}
468
469static int device_add_attrs(struct device *dev)
470{
471 struct class *class = dev->class;
472 const struct device_type *type = dev->type;
473 int error;
474
475 if (class) {
476 error = device_add_groups(dev, class->dev_groups);
477 if (error)
478 return error;
479 }
480
481 if (type) {
482 error = device_add_groups(dev, type->groups);
483 if (error)
484 goto err_remove_class_groups;
485 }
486
487 error = device_add_groups(dev, dev->groups);
488 if (error)
489 goto err_remove_type_groups;
490
491 if (device_supports_offline(dev) && !dev->offline_disabled) {
492 error = device_create_file(dev, &dev_attr_online);
493 if (error)
494 goto err_remove_dev_groups;
495 }
496
497 return 0;
498
499 err_remove_dev_groups:
500 device_remove_groups(dev, dev->groups);
501 err_remove_type_groups:
502 if (type)
503 device_remove_groups(dev, type->groups);
504 err_remove_class_groups:
505 if (class)
506 device_remove_groups(dev, class->dev_groups);
507
508 return error;
509}
510
511static void device_remove_attrs(struct device *dev)
512{
513 struct class *class = dev->class;
514 const struct device_type *type = dev->type;
515
516 device_remove_file(dev, &dev_attr_online);
517 device_remove_groups(dev, dev->groups);
518
519 if (type)
520 device_remove_groups(dev, type->groups);
521
522 if (class)
523 device_remove_groups(dev, class->dev_groups);
524}
525
526static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
527 char *buf)
528{
529 return print_dev_t(buf, dev->devt);
530}
531static DEVICE_ATTR_RO(dev);
532
533/* /sys/devices/ */
534struct kset *devices_kset;
535
536/**
537 * devices_kset_move_before - Move device in the devices_kset's list.
538 * @deva: Device to move.
539 * @devb: Device @deva should come before.
540 */
541static void devices_kset_move_before(struct device *deva, struct device *devb)
542{
543 if (!devices_kset)
544 return;
545 pr_debug("devices_kset: Moving %s before %s\n",
546 dev_name(deva), dev_name(devb));
547 spin_lock(&devices_kset->list_lock);
548 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
549 spin_unlock(&devices_kset->list_lock);
550}
551
552/**
553 * devices_kset_move_after - Move device in the devices_kset's list.
554 * @deva: Device to move
555 * @devb: Device @deva should come after.
556 */
557static void devices_kset_move_after(struct device *deva, struct device *devb)
558{
559 if (!devices_kset)
560 return;
561 pr_debug("devices_kset: Moving %s after %s\n",
562 dev_name(deva), dev_name(devb));
563 spin_lock(&devices_kset->list_lock);
564 list_move(&deva->kobj.entry, &devb->kobj.entry);
565 spin_unlock(&devices_kset->list_lock);
566}
567
568/**
569 * devices_kset_move_last - move the device to the end of devices_kset's list.
570 * @dev: device to move
571 */
572void devices_kset_move_last(struct device *dev)
573{
574 if (!devices_kset)
575 return;
576 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
577 spin_lock(&devices_kset->list_lock);
578 list_move_tail(&dev->kobj.entry, &devices_kset->list);
579 spin_unlock(&devices_kset->list_lock);
580}
581
582/**
583 * device_create_file - create sysfs attribute file for device.
584 * @dev: device.
585 * @attr: device attribute descriptor.
586 */
587int device_create_file(struct device *dev,
588 const struct device_attribute *attr)
589{
590 int error = 0;
591
592 if (dev) {
593 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
594 "Attribute %s: write permission without 'store'\n",
595 attr->attr.name);
596 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
597 "Attribute %s: read permission without 'show'\n",
598 attr->attr.name);
599 error = sysfs_create_file(&dev->kobj, &attr->attr);
600 }
601
602 return error;
603}
604EXPORT_SYMBOL_GPL(device_create_file);
605
606/**
607 * device_remove_file - remove sysfs attribute file.
608 * @dev: device.
609 * @attr: device attribute descriptor.
610 */
611void device_remove_file(struct device *dev,
612 const struct device_attribute *attr)
613{
614 if (dev)
615 sysfs_remove_file(&dev->kobj, &attr->attr);
616}
617EXPORT_SYMBOL_GPL(device_remove_file);
618
619/**
620 * device_remove_file_self - remove sysfs attribute file from its own method.
621 * @dev: device.
622 * @attr: device attribute descriptor.
623 *
624 * See kernfs_remove_self() for details.
625 */
626bool device_remove_file_self(struct device *dev,
627 const struct device_attribute *attr)
628{
629 if (dev)
630 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
631 else
632 return false;
633}
634EXPORT_SYMBOL_GPL(device_remove_file_self);
635
636/**
637 * device_create_bin_file - create sysfs binary attribute file for device.
638 * @dev: device.
639 * @attr: device binary attribute descriptor.
640 */
641int device_create_bin_file(struct device *dev,
642 const struct bin_attribute *attr)
643{
644 int error = -EINVAL;
645 if (dev)
646 error = sysfs_create_bin_file(&dev->kobj, attr);
647 return error;
648}
649EXPORT_SYMBOL_GPL(device_create_bin_file);
650
651/**
652 * device_remove_bin_file - remove sysfs binary attribute file
653 * @dev: device.
654 * @attr: device binary attribute descriptor.
655 */
656void device_remove_bin_file(struct device *dev,
657 const struct bin_attribute *attr)
658{
659 if (dev)
660 sysfs_remove_bin_file(&dev->kobj, attr);
661}
662EXPORT_SYMBOL_GPL(device_remove_bin_file);
663
664static void klist_children_get(struct klist_node *n)
665{
666 struct device_private *p = to_device_private_parent(n);
667 struct device *dev = p->device;
668
669 get_device(dev);
670}
671
672static void klist_children_put(struct klist_node *n)
673{
674 struct device_private *p = to_device_private_parent(n);
675 struct device *dev = p->device;
676
677 put_device(dev);
678}
679
680/**
681 * device_initialize - init device structure.
682 * @dev: device.
683 *
684 * This prepares the device for use by other layers by initializing
685 * its fields.
686 * It is the first half of device_register(), if called by
687 * that function, though it can also be called separately, so one
688 * may use @dev's fields. In particular, get_device()/put_device()
689 * may be used for reference counting of @dev after calling this
690 * function.
691 *
692 * All fields in @dev must be initialized by the caller to 0, except
693 * for those explicitly set to some other value. The simplest
694 * approach is to use kzalloc() to allocate the structure containing
695 * @dev.
696 *
697 * NOTE: Use put_device() to give up your reference instead of freeing
698 * @dev directly once you have called this function.
699 */
700void device_initialize(struct device *dev)
701{
702 dev->kobj.kset = devices_kset;
703 kobject_init(&dev->kobj, &device_ktype);
704 INIT_LIST_HEAD(&dev->dma_pools);
705 mutex_init(&dev->mutex);
706 lockdep_set_novalidate_class(&dev->mutex);
707 spin_lock_init(&dev->devres_lock);
708 INIT_LIST_HEAD(&dev->devres_head);
709 device_pm_init(dev);
710 set_dev_node(dev, -1);
711#ifdef CONFIG_GENERIC_MSI_IRQ
712 INIT_LIST_HEAD(&dev->msi_list);
713#endif
714}
715EXPORT_SYMBOL_GPL(device_initialize);
716
717struct kobject *virtual_device_parent(struct device *dev)
718{
719 static struct kobject *virtual_dir = NULL;
720
721 if (!virtual_dir)
722 virtual_dir = kobject_create_and_add("virtual",
723 &devices_kset->kobj);
724
725 return virtual_dir;
726}
727
728struct class_dir {
729 struct kobject kobj;
730 struct class *class;
731};
732
733#define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
734
735static void class_dir_release(struct kobject *kobj)
736{
737 struct class_dir *dir = to_class_dir(kobj);
738 kfree(dir);
739}
740
741static const
742struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
743{
744 struct class_dir *dir = to_class_dir(kobj);
745 return dir->class->ns_type;
746}
747
748static struct kobj_type class_dir_ktype = {
749 .release = class_dir_release,
750 .sysfs_ops = &kobj_sysfs_ops,
751 .child_ns_type = class_dir_child_ns_type
752};
753
754static struct kobject *
755class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
756{
757 struct class_dir *dir;
758 int retval;
759
760 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
761 if (!dir)
762 return NULL;
763
764 dir->class = class;
765 kobject_init(&dir->kobj, &class_dir_ktype);
766
767 dir->kobj.kset = &class->p->glue_dirs;
768
769 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
770 if (retval < 0) {
771 kobject_put(&dir->kobj);
772 return NULL;
773 }
774 return &dir->kobj;
775}
776
777static DEFINE_MUTEX(gdp_mutex);
778
779static struct kobject *get_device_parent(struct device *dev,
780 struct device *parent)
781{
782 if (dev->class) {
783 struct kobject *kobj = NULL;
784 struct kobject *parent_kobj;
785 struct kobject *k;
786
787#ifdef CONFIG_BLOCK
788 /* block disks show up in /sys/block */
789 if (sysfs_deprecated && dev->class == &block_class) {
790 if (parent && parent->class == &block_class)
791 return &parent->kobj;
792 return &block_class.p->subsys.kobj;
793 }
794#endif
795
796 /*
797 * If we have no parent, we live in "virtual".
798 * Class-devices with a non class-device as parent, live
799 * in a "glue" directory to prevent namespace collisions.
800 */
801 if (parent == NULL)
802 parent_kobj = virtual_device_parent(dev);
803 else if (parent->class && !dev->class->ns_type)
804 return &parent->kobj;
805 else
806 parent_kobj = &parent->kobj;
807
808 mutex_lock(&gdp_mutex);
809
810 /* find our class-directory at the parent and reference it */
811 spin_lock(&dev->class->p->glue_dirs.list_lock);
812 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
813 if (k->parent == parent_kobj) {
814 kobj = kobject_get(k);
815 break;
816 }
817 spin_unlock(&dev->class->p->glue_dirs.list_lock);
818 if (kobj) {
819 mutex_unlock(&gdp_mutex);
820 return kobj;
821 }
822
823 /* or create a new class-directory at the parent device */
824 k = class_dir_create_and_add(dev->class, parent_kobj);
825 /* do not emit an uevent for this simple "glue" directory */
826 mutex_unlock(&gdp_mutex);
827 return k;
828 }
829
830 /* subsystems can specify a default root directory for their devices */
831 if (!parent && dev->bus && dev->bus->dev_root)
832 return &dev->bus->dev_root->kobj;
833
834 if (parent)
835 return &parent->kobj;
836 return NULL;
837}
838
839static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
840{
841 /* see if we live in a "glue" directory */
842 if (!glue_dir || !dev->class ||
843 glue_dir->kset != &dev->class->p->glue_dirs)
844 return;
845
846 mutex_lock(&gdp_mutex);
847 kobject_put(glue_dir);
848 mutex_unlock(&gdp_mutex);
849}
850
851static void cleanup_device_parent(struct device *dev)
852{
853 cleanup_glue_dir(dev, dev->kobj.parent);
854}
855
856static int device_add_class_symlinks(struct device *dev)
857{
858 struct device_node *of_node = dev_of_node(dev);
859 int error;
860
861 if (of_node) {
862 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
863 if (error)
864 dev_warn(dev, "Error %d creating of_node link\n",error);
865 /* An error here doesn't warrant bringing down the device */
866 }
867
868 if (!dev->class)
869 return 0;
870
871 error = sysfs_create_link(&dev->kobj,
872 &dev->class->p->subsys.kobj,
873 "subsystem");
874 if (error)
875 goto out_devnode;
876
877 if (dev->parent && device_is_not_partition(dev)) {
878 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
879 "device");
880 if (error)
881 goto out_subsys;
882 }
883
884#ifdef CONFIG_BLOCK
885 /* /sys/block has directories and does not need symlinks */
886 if (sysfs_deprecated && dev->class == &block_class)
887 return 0;
888#endif
889
890 /* link in the class directory pointing to the device */
891 error = sysfs_create_link(&dev->class->p->subsys.kobj,
892 &dev->kobj, dev_name(dev));
893 if (error)
894 goto out_device;
895
896 return 0;
897
898out_device:
899 sysfs_remove_link(&dev->kobj, "device");
900
901out_subsys:
902 sysfs_remove_link(&dev->kobj, "subsystem");
903out_devnode:
904 sysfs_remove_link(&dev->kobj, "of_node");
905 return error;
906}
907
908static void device_remove_class_symlinks(struct device *dev)
909{
910 if (dev_of_node(dev))
911 sysfs_remove_link(&dev->kobj, "of_node");
912
913 if (!dev->class)
914 return;
915
916 if (dev->parent && device_is_not_partition(dev))
917 sysfs_remove_link(&dev->kobj, "device");
918 sysfs_remove_link(&dev->kobj, "subsystem");
919#ifdef CONFIG_BLOCK
920 if (sysfs_deprecated && dev->class == &block_class)
921 return;
922#endif
923 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
924}
925
926/**
927 * dev_set_name - set a device name
928 * @dev: device
929 * @fmt: format string for the device's name
930 */
931int dev_set_name(struct device *dev, const char *fmt, ...)
932{
933 va_list vargs;
934 int err;
935
936 va_start(vargs, fmt);
937 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
938 va_end(vargs);
939 return err;
940}
941EXPORT_SYMBOL_GPL(dev_set_name);
942
943/**
944 * device_to_dev_kobj - select a /sys/dev/ directory for the device
945 * @dev: device
946 *
947 * By default we select char/ for new entries. Setting class->dev_obj
948 * to NULL prevents an entry from being created. class->dev_kobj must
949 * be set (or cleared) before any devices are registered to the class
950 * otherwise device_create_sys_dev_entry() and
951 * device_remove_sys_dev_entry() will disagree about the presence of
952 * the link.
953 */
954static struct kobject *device_to_dev_kobj(struct device *dev)
955{
956 struct kobject *kobj;
957
958 if (dev->class)
959 kobj = dev->class->dev_kobj;
960 else
961 kobj = sysfs_dev_char_kobj;
962
963 return kobj;
964}
965
966static int device_create_sys_dev_entry(struct device *dev)
967{
968 struct kobject *kobj = device_to_dev_kobj(dev);
969 int error = 0;
970 char devt_str[15];
971
972 if (kobj) {
973 format_dev_t(devt_str, dev->devt);
974 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
975 }
976
977 return error;
978}
979
980static void device_remove_sys_dev_entry(struct device *dev)
981{
982 struct kobject *kobj = device_to_dev_kobj(dev);
983 char devt_str[15];
984
985 if (kobj) {
986 format_dev_t(devt_str, dev->devt);
987 sysfs_remove_link(kobj, devt_str);
988 }
989}
990
991int device_private_init(struct device *dev)
992{
993 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
994 if (!dev->p)
995 return -ENOMEM;
996 dev->p->device = dev;
997 klist_init(&dev->p->klist_children, klist_children_get,
998 klist_children_put);
999 INIT_LIST_HEAD(&dev->p->deferred_probe);
1000 return 0;
1001}
1002
1003/**
1004 * device_add - add device to device hierarchy.
1005 * @dev: device.
1006 *
1007 * This is part 2 of device_register(), though may be called
1008 * separately _iff_ device_initialize() has been called separately.
1009 *
1010 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1011 * to the global and sibling lists for the device, then
1012 * adds it to the other relevant subsystems of the driver model.
1013 *
1014 * Do not call this routine or device_register() more than once for
1015 * any device structure. The driver model core is not designed to work
1016 * with devices that get unregistered and then spring back to life.
1017 * (Among other things, it's very hard to guarantee that all references
1018 * to the previous incarnation of @dev have been dropped.) Allocate
1019 * and register a fresh new struct device instead.
1020 *
1021 * NOTE: _Never_ directly free @dev after calling this function, even
1022 * if it returned an error! Always use put_device() to give up your
1023 * reference instead.
1024 */
1025int device_add(struct device *dev)
1026{
1027 struct device *parent = NULL;
1028 struct kobject *kobj;
1029 struct class_interface *class_intf;
1030 int error = -EINVAL;
1031
1032 dev = get_device(dev);
1033 if (!dev)
1034 goto done;
1035
1036 if (!dev->p) {
1037 error = device_private_init(dev);
1038 if (error)
1039 goto done;
1040 }
1041
1042 /*
1043 * for statically allocated devices, which should all be converted
1044 * some day, we need to initialize the name. We prevent reading back
1045 * the name, and force the use of dev_name()
1046 */
1047 if (dev->init_name) {
1048 dev_set_name(dev, "%s", dev->init_name);
1049 dev->init_name = NULL;
1050 }
1051
1052 /* subsystems can specify simple device enumeration */
1053 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1054 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1055
1056 if (!dev_name(dev)) {
1057 error = -EINVAL;
1058 goto name_error;
1059 }
1060
1061 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1062
1063 parent = get_device(dev->parent);
1064 kobj = get_device_parent(dev, parent);
1065 if (kobj)
1066 dev->kobj.parent = kobj;
1067
1068 /* use parent numa_node */
1069 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1070 set_dev_node(dev, dev_to_node(parent));
1071
1072 /* first, register with generic layer. */
1073 /* we require the name to be set before, and pass NULL */
1074 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1075 if (error)
1076 goto Error;
1077
1078 /* notify platform of device entry */
1079 if (platform_notify)
1080 platform_notify(dev);
1081
1082 error = device_create_file(dev, &dev_attr_uevent);
1083 if (error)
1084 goto attrError;
1085
1086 error = device_add_class_symlinks(dev);
1087 if (error)
1088 goto SymlinkError;
1089 error = device_add_attrs(dev);
1090 if (error)
1091 goto AttrsError;
1092 error = bus_add_device(dev);
1093 if (error)
1094 goto BusError;
1095 error = dpm_sysfs_add(dev);
1096 if (error)
1097 goto DPMError;
1098 device_pm_add(dev);
1099
1100 if (MAJOR(dev->devt)) {
1101 error = device_create_file(dev, &dev_attr_dev);
1102 if (error)
1103 goto DevAttrError;
1104
1105 error = device_create_sys_dev_entry(dev);
1106 if (error)
1107 goto SysEntryError;
1108
1109 devtmpfs_create_node(dev);
1110 }
1111
1112 /* Notify clients of device addition. This call must come
1113 * after dpm_sysfs_add() and before kobject_uevent().
1114 */
1115 if (dev->bus)
1116 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1117 BUS_NOTIFY_ADD_DEVICE, dev);
1118
1119 kobject_uevent(&dev->kobj, KOBJ_ADD);
1120 bus_probe_device(dev);
1121 if (parent)
1122 klist_add_tail(&dev->p->knode_parent,
1123 &parent->p->klist_children);
1124
1125 if (dev->class) {
1126 mutex_lock(&dev->class->p->mutex);
1127 /* tie the class to the device */
1128 klist_add_tail(&dev->knode_class,
1129 &dev->class->p->klist_devices);
1130
1131 /* notify any interfaces that the device is here */
1132 list_for_each_entry(class_intf,
1133 &dev->class->p->interfaces, node)
1134 if (class_intf->add_dev)
1135 class_intf->add_dev(dev, class_intf);
1136 mutex_unlock(&dev->class->p->mutex);
1137 }
1138done:
1139 put_device(dev);
1140 return error;
1141 SysEntryError:
1142 if (MAJOR(dev->devt))
1143 device_remove_file(dev, &dev_attr_dev);
1144 DevAttrError:
1145 device_pm_remove(dev);
1146 dpm_sysfs_remove(dev);
1147 DPMError:
1148 bus_remove_device(dev);
1149 BusError:
1150 device_remove_attrs(dev);
1151 AttrsError:
1152 device_remove_class_symlinks(dev);
1153 SymlinkError:
1154 device_remove_file(dev, &dev_attr_uevent);
1155 attrError:
1156 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1157 kobject_del(&dev->kobj);
1158 Error:
1159 cleanup_device_parent(dev);
1160 put_device(parent);
1161name_error:
1162 kfree(dev->p);
1163 dev->p = NULL;
1164 goto done;
1165}
1166EXPORT_SYMBOL_GPL(device_add);
1167
1168/**
1169 * device_register - register a device with the system.
1170 * @dev: pointer to the device structure
1171 *
1172 * This happens in two clean steps - initialize the device
1173 * and add it to the system. The two steps can be called
1174 * separately, but this is the easiest and most common.
1175 * I.e. you should only call the two helpers separately if
1176 * have a clearly defined need to use and refcount the device
1177 * before it is added to the hierarchy.
1178 *
1179 * For more information, see the kerneldoc for device_initialize()
1180 * and device_add().
1181 *
1182 * NOTE: _Never_ directly free @dev after calling this function, even
1183 * if it returned an error! Always use put_device() to give up the
1184 * reference initialized in this function instead.
1185 */
1186int device_register(struct device *dev)
1187{
1188 device_initialize(dev);
1189 return device_add(dev);
1190}
1191EXPORT_SYMBOL_GPL(device_register);
1192
1193/**
1194 * get_device - increment reference count for device.
1195 * @dev: device.
1196 *
1197 * This simply forwards the call to kobject_get(), though
1198 * we do take care to provide for the case that we get a NULL
1199 * pointer passed in.
1200 */
1201struct device *get_device(struct device *dev)
1202{
1203 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1204}
1205EXPORT_SYMBOL_GPL(get_device);
1206
1207/**
1208 * put_device - decrement reference count.
1209 * @dev: device in question.
1210 */
1211void put_device(struct device *dev)
1212{
1213 /* might_sleep(); */
1214 if (dev)
1215 kobject_put(&dev->kobj);
1216}
1217EXPORT_SYMBOL_GPL(put_device);
1218
1219/**
1220 * device_del - delete device from system.
1221 * @dev: device.
1222 *
1223 * This is the first part of the device unregistration
1224 * sequence. This removes the device from the lists we control
1225 * from here, has it removed from the other driver model
1226 * subsystems it was added to in device_add(), and removes it
1227 * from the kobject hierarchy.
1228 *
1229 * NOTE: this should be called manually _iff_ device_add() was
1230 * also called manually.
1231 */
1232void device_del(struct device *dev)
1233{
1234 struct device *parent = dev->parent;
1235 struct class_interface *class_intf;
1236
1237 /* Notify clients of device removal. This call must come
1238 * before dpm_sysfs_remove().
1239 */
1240 if (dev->bus)
1241 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1242 BUS_NOTIFY_DEL_DEVICE, dev);
1243 dpm_sysfs_remove(dev);
1244 if (parent)
1245 klist_del(&dev->p->knode_parent);
1246 if (MAJOR(dev->devt)) {
1247 devtmpfs_delete_node(dev);
1248 device_remove_sys_dev_entry(dev);
1249 device_remove_file(dev, &dev_attr_dev);
1250 }
1251 if (dev->class) {
1252 device_remove_class_symlinks(dev);
1253
1254 mutex_lock(&dev->class->p->mutex);
1255 /* notify any interfaces that the device is now gone */
1256 list_for_each_entry(class_intf,
1257 &dev->class->p->interfaces, node)
1258 if (class_intf->remove_dev)
1259 class_intf->remove_dev(dev, class_intf);
1260 /* remove the device from the class list */
1261 klist_del(&dev->knode_class);
1262 mutex_unlock(&dev->class->p->mutex);
1263 }
1264 device_remove_file(dev, &dev_attr_uevent);
1265 device_remove_attrs(dev);
1266 bus_remove_device(dev);
1267 device_pm_remove(dev);
1268 driver_deferred_probe_del(dev);
1269
1270 /* Notify the platform of the removal, in case they
1271 * need to do anything...
1272 */
1273 if (platform_notify_remove)
1274 platform_notify_remove(dev);
1275 if (dev->bus)
1276 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1277 BUS_NOTIFY_REMOVED_DEVICE, dev);
1278 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1279 cleanup_device_parent(dev);
1280 kobject_del(&dev->kobj);
1281 put_device(parent);
1282}
1283EXPORT_SYMBOL_GPL(device_del);
1284
1285/**
1286 * device_unregister - unregister device from system.
1287 * @dev: device going away.
1288 *
1289 * We do this in two parts, like we do device_register(). First,
1290 * we remove it from all the subsystems with device_del(), then
1291 * we decrement the reference count via put_device(). If that
1292 * is the final reference count, the device will be cleaned up
1293 * via device_release() above. Otherwise, the structure will
1294 * stick around until the final reference to the device is dropped.
1295 */
1296void device_unregister(struct device *dev)
1297{
1298 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1299 device_del(dev);
1300 put_device(dev);
1301}
1302EXPORT_SYMBOL_GPL(device_unregister);
1303
1304static struct device *prev_device(struct klist_iter *i)
1305{
1306 struct klist_node *n = klist_prev(i);
1307 struct device *dev = NULL;
1308 struct device_private *p;
1309
1310 if (n) {
1311 p = to_device_private_parent(n);
1312 dev = p->device;
1313 }
1314 return dev;
1315}
1316
1317static struct device *next_device(struct klist_iter *i)
1318{
1319 struct klist_node *n = klist_next(i);
1320 struct device *dev = NULL;
1321 struct device_private *p;
1322
1323 if (n) {
1324 p = to_device_private_parent(n);
1325 dev = p->device;
1326 }
1327 return dev;
1328}
1329
1330/**
1331 * device_get_devnode - path of device node file
1332 * @dev: device
1333 * @mode: returned file access mode
1334 * @uid: returned file owner
1335 * @gid: returned file group
1336 * @tmp: possibly allocated string
1337 *
1338 * Return the relative path of a possible device node.
1339 * Non-default names may need to allocate a memory to compose
1340 * a name. This memory is returned in tmp and needs to be
1341 * freed by the caller.
1342 */
1343const char *device_get_devnode(struct device *dev,
1344 umode_t *mode, kuid_t *uid, kgid_t *gid,
1345 const char **tmp)
1346{
1347 char *s;
1348
1349 *tmp = NULL;
1350
1351 /* the device type may provide a specific name */
1352 if (dev->type && dev->type->devnode)
1353 *tmp = dev->type->devnode(dev, mode, uid, gid);
1354 if (*tmp)
1355 return *tmp;
1356
1357 /* the class may provide a specific name */
1358 if (dev->class && dev->class->devnode)
1359 *tmp = dev->class->devnode(dev, mode);
1360 if (*tmp)
1361 return *tmp;
1362
1363 /* return name without allocation, tmp == NULL */
1364 if (strchr(dev_name(dev), '!') == NULL)
1365 return dev_name(dev);
1366
1367 /* replace '!' in the name with '/' */
1368 s = kstrdup(dev_name(dev), GFP_KERNEL);
1369 if (!s)
1370 return NULL;
1371 strreplace(s, '!', '/');
1372 return *tmp = s;
1373}
1374
1375/**
1376 * device_for_each_child - device child iterator.
1377 * @parent: parent struct device.
1378 * @fn: function to be called for each device.
1379 * @data: data for the callback.
1380 *
1381 * Iterate over @parent's child devices, and call @fn for each,
1382 * passing it @data.
1383 *
1384 * We check the return of @fn each time. If it returns anything
1385 * other than 0, we break out and return that value.
1386 */
1387int device_for_each_child(struct device *parent, void *data,
1388 int (*fn)(struct device *dev, void *data))
1389{
1390 struct klist_iter i;
1391 struct device *child;
1392 int error = 0;
1393
1394 if (!parent->p)
1395 return 0;
1396
1397 klist_iter_init(&parent->p->klist_children, &i);
1398 while ((child = next_device(&i)) && !error)
1399 error = fn(child, data);
1400 klist_iter_exit(&i);
1401 return error;
1402}
1403EXPORT_SYMBOL_GPL(device_for_each_child);
1404
1405/**
1406 * device_for_each_child_reverse - device child iterator in reversed order.
1407 * @parent: parent struct device.
1408 * @fn: function to be called for each device.
1409 * @data: data for the callback.
1410 *
1411 * Iterate over @parent's child devices, and call @fn for each,
1412 * passing it @data.
1413 *
1414 * We check the return of @fn each time. If it returns anything
1415 * other than 0, we break out and return that value.
1416 */
1417int device_for_each_child_reverse(struct device *parent, void *data,
1418 int (*fn)(struct device *dev, void *data))
1419{
1420 struct klist_iter i;
1421 struct device *child;
1422 int error = 0;
1423
1424 if (!parent->p)
1425 return 0;
1426
1427 klist_iter_init(&parent->p->klist_children, &i);
1428 while ((child = prev_device(&i)) && !error)
1429 error = fn(child, data);
1430 klist_iter_exit(&i);
1431 return error;
1432}
1433EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
1434
1435/**
1436 * device_find_child - device iterator for locating a particular device.
1437 * @parent: parent struct device
1438 * @match: Callback function to check device
1439 * @data: Data to pass to match function
1440 *
1441 * This is similar to the device_for_each_child() function above, but it
1442 * returns a reference to a device that is 'found' for later use, as
1443 * determined by the @match callback.
1444 *
1445 * The callback should return 0 if the device doesn't match and non-zero
1446 * if it does. If the callback returns non-zero and a reference to the
1447 * current device can be obtained, this function will return to the caller
1448 * and not iterate over any more devices.
1449 *
1450 * NOTE: you will need to drop the reference with put_device() after use.
1451 */
1452struct device *device_find_child(struct device *parent, void *data,
1453 int (*match)(struct device *dev, void *data))
1454{
1455 struct klist_iter i;
1456 struct device *child;
1457
1458 if (!parent)
1459 return NULL;
1460
1461 klist_iter_init(&parent->p->klist_children, &i);
1462 while ((child = next_device(&i)))
1463 if (match(child, data) && get_device(child))
1464 break;
1465 klist_iter_exit(&i);
1466 return child;
1467}
1468EXPORT_SYMBOL_GPL(device_find_child);
1469
1470int __init devices_init(void)
1471{
1472 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
1473 if (!devices_kset)
1474 return -ENOMEM;
1475 dev_kobj = kobject_create_and_add("dev", NULL);
1476 if (!dev_kobj)
1477 goto dev_kobj_err;
1478 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
1479 if (!sysfs_dev_block_kobj)
1480 goto block_kobj_err;
1481 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
1482 if (!sysfs_dev_char_kobj)
1483 goto char_kobj_err;
1484
1485 return 0;
1486
1487 char_kobj_err:
1488 kobject_put(sysfs_dev_block_kobj);
1489 block_kobj_err:
1490 kobject_put(dev_kobj);
1491 dev_kobj_err:
1492 kset_unregister(devices_kset);
1493 return -ENOMEM;
1494}
1495
1496static int device_check_offline(struct device *dev, void *not_used)
1497{
1498 int ret;
1499
1500 ret = device_for_each_child(dev, NULL, device_check_offline);
1501 if (ret)
1502 return ret;
1503
1504 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
1505}
1506
1507/**
1508 * device_offline - Prepare the device for hot-removal.
1509 * @dev: Device to be put offline.
1510 *
1511 * Execute the device bus type's .offline() callback, if present, to prepare
1512 * the device for a subsequent hot-removal. If that succeeds, the device must
1513 * not be used until either it is removed or its bus type's .online() callback
1514 * is executed.
1515 *
1516 * Call under device_hotplug_lock.
1517 */
1518int device_offline(struct device *dev)
1519{
1520 int ret;
1521
1522 if (dev->offline_disabled)
1523 return -EPERM;
1524
1525 ret = device_for_each_child(dev, NULL, device_check_offline);
1526 if (ret)
1527 return ret;
1528
1529 device_lock(dev);
1530 if (device_supports_offline(dev)) {
1531 if (dev->offline) {
1532 ret = 1;
1533 } else {
1534 ret = dev->bus->offline(dev);
1535 if (!ret) {
1536 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
1537 dev->offline = true;
1538 }
1539 }
1540 }
1541 device_unlock(dev);
1542
1543 return ret;
1544}
1545
1546/**
1547 * device_online - Put the device back online after successful device_offline().
1548 * @dev: Device to be put back online.
1549 *
1550 * If device_offline() has been successfully executed for @dev, but the device
1551 * has not been removed subsequently, execute its bus type's .online() callback
1552 * to indicate that the device can be used again.
1553 *
1554 * Call under device_hotplug_lock.
1555 */
1556int device_online(struct device *dev)
1557{
1558 int ret = 0;
1559
1560 device_lock(dev);
1561 if (device_supports_offline(dev)) {
1562 if (dev->offline) {
1563 ret = dev->bus->online(dev);
1564 if (!ret) {
1565 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
1566 dev->offline = false;
1567 }
1568 } else {
1569 ret = 1;
1570 }
1571 }
1572 device_unlock(dev);
1573
1574 return ret;
1575}
1576
1577struct root_device {
1578 struct device dev;
1579 struct module *owner;
1580};
1581
1582static inline struct root_device *to_root_device(struct device *d)
1583{
1584 return container_of(d, struct root_device, dev);
1585}
1586
1587static void root_device_release(struct device *dev)
1588{
1589 kfree(to_root_device(dev));
1590}
1591
1592/**
1593 * __root_device_register - allocate and register a root device
1594 * @name: root device name
1595 * @owner: owner module of the root device, usually THIS_MODULE
1596 *
1597 * This function allocates a root device and registers it
1598 * using device_register(). In order to free the returned
1599 * device, use root_device_unregister().
1600 *
1601 * Root devices are dummy devices which allow other devices
1602 * to be grouped under /sys/devices. Use this function to
1603 * allocate a root device and then use it as the parent of
1604 * any device which should appear under /sys/devices/{name}
1605 *
1606 * The /sys/devices/{name} directory will also contain a
1607 * 'module' symlink which points to the @owner directory
1608 * in sysfs.
1609 *
1610 * Returns &struct device pointer on success, or ERR_PTR() on error.
1611 *
1612 * Note: You probably want to use root_device_register().
1613 */
1614struct device *__root_device_register(const char *name, struct module *owner)
1615{
1616 struct root_device *root;
1617 int err = -ENOMEM;
1618
1619 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
1620 if (!root)
1621 return ERR_PTR(err);
1622
1623 err = dev_set_name(&root->dev, "%s", name);
1624 if (err) {
1625 kfree(root);
1626 return ERR_PTR(err);
1627 }
1628
1629 root->dev.release = root_device_release;
1630
1631 err = device_register(&root->dev);
1632 if (err) {
1633 put_device(&root->dev);
1634 return ERR_PTR(err);
1635 }
1636
1637#ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
1638 if (owner) {
1639 struct module_kobject *mk = &owner->mkobj;
1640
1641 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
1642 if (err) {
1643 device_unregister(&root->dev);
1644 return ERR_PTR(err);
1645 }
1646 root->owner = owner;
1647 }
1648#endif
1649
1650 return &root->dev;
1651}
1652EXPORT_SYMBOL_GPL(__root_device_register);
1653
1654/**
1655 * root_device_unregister - unregister and free a root device
1656 * @dev: device going away
1657 *
1658 * This function unregisters and cleans up a device that was created by
1659 * root_device_register().
1660 */
1661void root_device_unregister(struct device *dev)
1662{
1663 struct root_device *root = to_root_device(dev);
1664
1665 if (root->owner)
1666 sysfs_remove_link(&root->dev.kobj, "module");
1667
1668 device_unregister(dev);
1669}
1670EXPORT_SYMBOL_GPL(root_device_unregister);
1671
1672
1673static void device_create_release(struct device *dev)
1674{
1675 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1676 kfree(dev);
1677}
1678
1679static struct device *
1680device_create_groups_vargs(struct class *class, struct device *parent,
1681 dev_t devt, void *drvdata,
1682 const struct attribute_group **groups,
1683 const char *fmt, va_list args)
1684{
1685 struct device *dev = NULL;
1686 int retval = -ENODEV;
1687
1688 if (class == NULL || IS_ERR(class))
1689 goto error;
1690
1691 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1692 if (!dev) {
1693 retval = -ENOMEM;
1694 goto error;
1695 }
1696
1697 device_initialize(dev);
1698 dev->devt = devt;
1699 dev->class = class;
1700 dev->parent = parent;
1701 dev->groups = groups;
1702 dev->release = device_create_release;
1703 dev_set_drvdata(dev, drvdata);
1704
1705 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
1706 if (retval)
1707 goto error;
1708
1709 retval = device_add(dev);
1710 if (retval)
1711 goto error;
1712
1713 return dev;
1714
1715error:
1716 put_device(dev);
1717 return ERR_PTR(retval);
1718}
1719
1720/**
1721 * device_create_vargs - creates a device and registers it with sysfs
1722 * @class: pointer to the struct class that this device should be registered to
1723 * @parent: pointer to the parent struct device of this new device, if any
1724 * @devt: the dev_t for the char device to be added
1725 * @drvdata: the data to be added to the device for callbacks
1726 * @fmt: string for the device's name
1727 * @args: va_list for the device's name
1728 *
1729 * This function can be used by char device classes. A struct device
1730 * will be created in sysfs, registered to the specified class.
1731 *
1732 * A "dev" file will be created, showing the dev_t for the device, if
1733 * the dev_t is not 0,0.
1734 * If a pointer to a parent struct device is passed in, the newly created
1735 * struct device will be a child of that device in sysfs.
1736 * The pointer to the struct device will be returned from the call.
1737 * Any further sysfs files that might be required can be created using this
1738 * pointer.
1739 *
1740 * Returns &struct device pointer on success, or ERR_PTR() on error.
1741 *
1742 * Note: the struct class passed to this function must have previously
1743 * been created with a call to class_create().
1744 */
1745struct device *device_create_vargs(struct class *class, struct device *parent,
1746 dev_t devt, void *drvdata, const char *fmt,
1747 va_list args)
1748{
1749 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
1750 fmt, args);
1751}
1752EXPORT_SYMBOL_GPL(device_create_vargs);
1753
1754/**
1755 * device_create - creates a device and registers it with sysfs
1756 * @class: pointer to the struct class that this device should be registered to
1757 * @parent: pointer to the parent struct device of this new device, if any
1758 * @devt: the dev_t for the char device to be added
1759 * @drvdata: the data to be added to the device for callbacks
1760 * @fmt: string for the device's name
1761 *
1762 * This function can be used by char device classes. A struct device
1763 * will be created in sysfs, registered to the specified class.
1764 *
1765 * A "dev" file will be created, showing the dev_t for the device, if
1766 * the dev_t is not 0,0.
1767 * If a pointer to a parent struct device is passed in, the newly created
1768 * struct device will be a child of that device in sysfs.
1769 * The pointer to the struct device will be returned from the call.
1770 * Any further sysfs files that might be required can be created using this
1771 * pointer.
1772 *
1773 * Returns &struct device pointer on success, or ERR_PTR() on error.
1774 *
1775 * Note: the struct class passed to this function must have previously
1776 * been created with a call to class_create().
1777 */
1778struct device *device_create(struct class *class, struct device *parent,
1779 dev_t devt, void *drvdata, const char *fmt, ...)
1780{
1781 va_list vargs;
1782 struct device *dev;
1783
1784 va_start(vargs, fmt);
1785 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
1786 va_end(vargs);
1787 return dev;
1788}
1789EXPORT_SYMBOL_GPL(device_create);
1790
1791/**
1792 * device_create_with_groups - creates a device and registers it with sysfs
1793 * @class: pointer to the struct class that this device should be registered to
1794 * @parent: pointer to the parent struct device of this new device, if any
1795 * @devt: the dev_t for the char device to be added
1796 * @drvdata: the data to be added to the device for callbacks
1797 * @groups: NULL-terminated list of attribute groups to be created
1798 * @fmt: string for the device's name
1799 *
1800 * This function can be used by char device classes. A struct device
1801 * will be created in sysfs, registered to the specified class.
1802 * Additional attributes specified in the groups parameter will also
1803 * be created automatically.
1804 *
1805 * A "dev" file will be created, showing the dev_t for the device, if
1806 * the dev_t is not 0,0.
1807 * If a pointer to a parent struct device is passed in, the newly created
1808 * struct device will be a child of that device in sysfs.
1809 * The pointer to the struct device will be returned from the call.
1810 * Any further sysfs files that might be required can be created using this
1811 * pointer.
1812 *
1813 * Returns &struct device pointer on success, or ERR_PTR() on error.
1814 *
1815 * Note: the struct class passed to this function must have previously
1816 * been created with a call to class_create().
1817 */
1818struct device *device_create_with_groups(struct class *class,
1819 struct device *parent, dev_t devt,
1820 void *drvdata,
1821 const struct attribute_group **groups,
1822 const char *fmt, ...)
1823{
1824 va_list vargs;
1825 struct device *dev;
1826
1827 va_start(vargs, fmt);
1828 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
1829 fmt, vargs);
1830 va_end(vargs);
1831 return dev;
1832}
1833EXPORT_SYMBOL_GPL(device_create_with_groups);
1834
1835static int __match_devt(struct device *dev, const void *data)
1836{
1837 const dev_t *devt = data;
1838
1839 return dev->devt == *devt;
1840}
1841
1842/**
1843 * device_destroy - removes a device that was created with device_create()
1844 * @class: pointer to the struct class that this device was registered with
1845 * @devt: the dev_t of the device that was previously registered
1846 *
1847 * This call unregisters and cleans up a device that was created with a
1848 * call to device_create().
1849 */
1850void device_destroy(struct class *class, dev_t devt)
1851{
1852 struct device *dev;
1853
1854 dev = class_find_device(class, NULL, &devt, __match_devt);
1855 if (dev) {
1856 put_device(dev);
1857 device_unregister(dev);
1858 }
1859}
1860EXPORT_SYMBOL_GPL(device_destroy);
1861
1862/**
1863 * device_rename - renames a device
1864 * @dev: the pointer to the struct device to be renamed
1865 * @new_name: the new name of the device
1866 *
1867 * It is the responsibility of the caller to provide mutual
1868 * exclusion between two different calls of device_rename
1869 * on the same device to ensure that new_name is valid and
1870 * won't conflict with other devices.
1871 *
1872 * Note: Don't call this function. Currently, the networking layer calls this
1873 * function, but that will change. The following text from Kay Sievers offers
1874 * some insight:
1875 *
1876 * Renaming devices is racy at many levels, symlinks and other stuff are not
1877 * replaced atomically, and you get a "move" uevent, but it's not easy to
1878 * connect the event to the old and new device. Device nodes are not renamed at
1879 * all, there isn't even support for that in the kernel now.
1880 *
1881 * In the meantime, during renaming, your target name might be taken by another
1882 * driver, creating conflicts. Or the old name is taken directly after you
1883 * renamed it -- then you get events for the same DEVPATH, before you even see
1884 * the "move" event. It's just a mess, and nothing new should ever rely on
1885 * kernel device renaming. Besides that, it's not even implemented now for
1886 * other things than (driver-core wise very simple) network devices.
1887 *
1888 * We are currently about to change network renaming in udev to completely
1889 * disallow renaming of devices in the same namespace as the kernel uses,
1890 * because we can't solve the problems properly, that arise with swapping names
1891 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
1892 * be allowed to some other name than eth[0-9]*, for the aforementioned
1893 * reasons.
1894 *
1895 * Make up a "real" name in the driver before you register anything, or add
1896 * some other attributes for userspace to find the device, or use udev to add
1897 * symlinks -- but never rename kernel devices later, it's a complete mess. We
1898 * don't even want to get into that and try to implement the missing pieces in
1899 * the core. We really have other pieces to fix in the driver core mess. :)
1900 */
1901int device_rename(struct device *dev, const char *new_name)
1902{
1903 struct kobject *kobj = &dev->kobj;
1904 char *old_device_name = NULL;
1905 int error;
1906
1907 dev = get_device(dev);
1908 if (!dev)
1909 return -EINVAL;
1910
1911 dev_dbg(dev, "renaming to %s\n", new_name);
1912
1913 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
1914 if (!old_device_name) {
1915 error = -ENOMEM;
1916 goto out;
1917 }
1918
1919 if (dev->class) {
1920 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
1921 kobj, old_device_name,
1922 new_name, kobject_namespace(kobj));
1923 if (error)
1924 goto out;
1925 }
1926
1927 error = kobject_rename(kobj, new_name);
1928 if (error)
1929 goto out;
1930
1931out:
1932 put_device(dev);
1933
1934 kfree(old_device_name);
1935
1936 return error;
1937}
1938EXPORT_SYMBOL_GPL(device_rename);
1939
1940static int device_move_class_links(struct device *dev,
1941 struct device *old_parent,
1942 struct device *new_parent)
1943{
1944 int error = 0;
1945
1946 if (old_parent)
1947 sysfs_remove_link(&dev->kobj, "device");
1948 if (new_parent)
1949 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
1950 "device");
1951 return error;
1952}
1953
1954/**
1955 * device_move - moves a device to a new parent
1956 * @dev: the pointer to the struct device to be moved
1957 * @new_parent: the new parent of the device (can by NULL)
1958 * @dpm_order: how to reorder the dpm_list
1959 */
1960int device_move(struct device *dev, struct device *new_parent,
1961 enum dpm_order dpm_order)
1962{
1963 int error;
1964 struct device *old_parent;
1965 struct kobject *new_parent_kobj;
1966
1967 dev = get_device(dev);
1968 if (!dev)
1969 return -EINVAL;
1970
1971 device_pm_lock();
1972 new_parent = get_device(new_parent);
1973 new_parent_kobj = get_device_parent(dev, new_parent);
1974
1975 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
1976 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
1977 error = kobject_move(&dev->kobj, new_parent_kobj);
1978 if (error) {
1979 cleanup_glue_dir(dev, new_parent_kobj);
1980 put_device(new_parent);
1981 goto out;
1982 }
1983 old_parent = dev->parent;
1984 dev->parent = new_parent;
1985 if (old_parent)
1986 klist_remove(&dev->p->knode_parent);
1987 if (new_parent) {
1988 klist_add_tail(&dev->p->knode_parent,
1989 &new_parent->p->klist_children);
1990 set_dev_node(dev, dev_to_node(new_parent));
1991 }
1992
1993 if (dev->class) {
1994 error = device_move_class_links(dev, old_parent, new_parent);
1995 if (error) {
1996 /* We ignore errors on cleanup since we're hosed anyway... */
1997 device_move_class_links(dev, new_parent, old_parent);
1998 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
1999 if (new_parent)
2000 klist_remove(&dev->p->knode_parent);
2001 dev->parent = old_parent;
2002 if (old_parent) {
2003 klist_add_tail(&dev->p->knode_parent,
2004 &old_parent->p->klist_children);
2005 set_dev_node(dev, dev_to_node(old_parent));
2006 }
2007 }
2008 cleanup_glue_dir(dev, new_parent_kobj);
2009 put_device(new_parent);
2010 goto out;
2011 }
2012 }
2013 switch (dpm_order) {
2014 case DPM_ORDER_NONE:
2015 break;
2016 case DPM_ORDER_DEV_AFTER_PARENT:
2017 device_pm_move_after(dev, new_parent);
2018 devices_kset_move_after(dev, new_parent);
2019 break;
2020 case DPM_ORDER_PARENT_BEFORE_DEV:
2021 device_pm_move_before(new_parent, dev);
2022 devices_kset_move_before(new_parent, dev);
2023 break;
2024 case DPM_ORDER_DEV_LAST:
2025 device_pm_move_last(dev);
2026 devices_kset_move_last(dev);
2027 break;
2028 }
2029
2030 put_device(old_parent);
2031out:
2032 device_pm_unlock();
2033 put_device(dev);
2034 return error;
2035}
2036EXPORT_SYMBOL_GPL(device_move);
2037
2038/**
2039 * device_shutdown - call ->shutdown() on each device to shutdown.
2040 */
2041void device_shutdown(void)
2042{
2043 struct device *dev, *parent;
2044
2045 spin_lock(&devices_kset->list_lock);
2046 /*
2047 * Walk the devices list backward, shutting down each in turn.
2048 * Beware that device unplug events may also start pulling
2049 * devices offline, even as the system is shutting down.
2050 */
2051 while (!list_empty(&devices_kset->list)) {
2052 dev = list_entry(devices_kset->list.prev, struct device,
2053 kobj.entry);
2054
2055 /*
2056 * hold reference count of device's parent to
2057 * prevent it from being freed because parent's
2058 * lock is to be held
2059 */
2060 parent = get_device(dev->parent);
2061 get_device(dev);
2062 /*
2063 * Make sure the device is off the kset list, in the
2064 * event that dev->*->shutdown() doesn't remove it.
2065 */
2066 list_del_init(&dev->kobj.entry);
2067 spin_unlock(&devices_kset->list_lock);
2068
2069 /* hold lock to avoid race with probe/release */
2070 if (parent)
2071 device_lock(parent);
2072 device_lock(dev);
2073
2074 /* Don't allow any more runtime suspends */
2075 pm_runtime_get_noresume(dev);
2076 pm_runtime_barrier(dev);
2077
2078 if (dev->bus && dev->bus->shutdown) {
2079 if (initcall_debug)
2080 dev_info(dev, "shutdown\n");
2081 dev->bus->shutdown(dev);
2082 } else if (dev->driver && dev->driver->shutdown) {
2083 if (initcall_debug)
2084 dev_info(dev, "shutdown\n");
2085 dev->driver->shutdown(dev);
2086 }
2087
2088 device_unlock(dev);
2089 if (parent)
2090 device_unlock(parent);
2091
2092 put_device(dev);
2093 put_device(parent);
2094
2095 spin_lock(&devices_kset->list_lock);
2096 }
2097 spin_unlock(&devices_kset->list_lock);
2098}
2099
2100/*
2101 * Device logging functions
2102 */
2103
2104#ifdef CONFIG_PRINTK
2105static int
2106create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2107{
2108 const char *subsys;
2109 size_t pos = 0;
2110
2111 if (dev->class)
2112 subsys = dev->class->name;
2113 else if (dev->bus)
2114 subsys = dev->bus->name;
2115 else
2116 return 0;
2117
2118 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2119 if (pos >= hdrlen)
2120 goto overflow;
2121
2122 /*
2123 * Add device identifier DEVICE=:
2124 * b12:8 block dev_t
2125 * c127:3 char dev_t
2126 * n8 netdev ifindex
2127 * +sound:card0 subsystem:devname
2128 */
2129 if (MAJOR(dev->devt)) {
2130 char c;
2131
2132 if (strcmp(subsys, "block") == 0)
2133 c = 'b';
2134 else
2135 c = 'c';
2136 pos++;
2137 pos += snprintf(hdr + pos, hdrlen - pos,
2138 "DEVICE=%c%u:%u",
2139 c, MAJOR(dev->devt), MINOR(dev->devt));
2140 } else if (strcmp(subsys, "net") == 0) {
2141 struct net_device *net = to_net_dev(dev);
2142
2143 pos++;
2144 pos += snprintf(hdr + pos, hdrlen - pos,
2145 "DEVICE=n%u", net->ifindex);
2146 } else {
2147 pos++;
2148 pos += snprintf(hdr + pos, hdrlen - pos,
2149 "DEVICE=+%s:%s", subsys, dev_name(dev));
2150 }
2151
2152 if (pos >= hdrlen)
2153 goto overflow;
2154
2155 return pos;
2156
2157overflow:
2158 dev_WARN(dev, "device/subsystem name too long");
2159 return 0;
2160}
2161
2162int dev_vprintk_emit(int level, const struct device *dev,
2163 const char *fmt, va_list args)
2164{
2165 char hdr[128];
2166 size_t hdrlen;
2167
2168 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2169
2170 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2171}
2172EXPORT_SYMBOL(dev_vprintk_emit);
2173
2174int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2175{
2176 va_list args;
2177 int r;
2178
2179 va_start(args, fmt);
2180
2181 r = dev_vprintk_emit(level, dev, fmt, args);
2182
2183 va_end(args);
2184
2185 return r;
2186}
2187EXPORT_SYMBOL(dev_printk_emit);
2188
2189static void __dev_printk(const char *level, const struct device *dev,
2190 struct va_format *vaf)
2191{
2192 if (dev)
2193 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2194 dev_driver_string(dev), dev_name(dev), vaf);
2195 else
2196 printk("%s(NULL device *): %pV", level, vaf);
2197}
2198
2199void dev_printk(const char *level, const struct device *dev,
2200 const char *fmt, ...)
2201{
2202 struct va_format vaf;
2203 va_list args;
2204
2205 va_start(args, fmt);
2206
2207 vaf.fmt = fmt;
2208 vaf.va = &args;
2209
2210 __dev_printk(level, dev, &vaf);
2211
2212 va_end(args);
2213}
2214EXPORT_SYMBOL(dev_printk);
2215
2216#define define_dev_printk_level(func, kern_level) \
2217void func(const struct device *dev, const char *fmt, ...) \
2218{ \
2219 struct va_format vaf; \
2220 va_list args; \
2221 \
2222 va_start(args, fmt); \
2223 \
2224 vaf.fmt = fmt; \
2225 vaf.va = &args; \
2226 \
2227 __dev_printk(kern_level, dev, &vaf); \
2228 \
2229 va_end(args); \
2230} \
2231EXPORT_SYMBOL(func);
2232
2233define_dev_printk_level(dev_emerg, KERN_EMERG);
2234define_dev_printk_level(dev_alert, KERN_ALERT);
2235define_dev_printk_level(dev_crit, KERN_CRIT);
2236define_dev_printk_level(dev_err, KERN_ERR);
2237define_dev_printk_level(dev_warn, KERN_WARNING);
2238define_dev_printk_level(dev_notice, KERN_NOTICE);
2239define_dev_printk_level(_dev_info, KERN_INFO);
2240
2241#endif
2242
2243static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2244{
2245 return fwnode && !IS_ERR(fwnode->secondary);
2246}
2247
2248/**
2249 * set_primary_fwnode - Change the primary firmware node of a given device.
2250 * @dev: Device to handle.
2251 * @fwnode: New primary firmware node of the device.
2252 *
2253 * Set the device's firmware node pointer to @fwnode, but if a secondary
2254 * firmware node of the device is present, preserve it.
2255 */
2256void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2257{
2258 if (fwnode) {
2259 struct fwnode_handle *fn = dev->fwnode;
2260
2261 if (fwnode_is_primary(fn))
2262 fn = fn->secondary;
2263
2264 if (fn) {
2265 WARN_ON(fwnode->secondary);
2266 fwnode->secondary = fn;
2267 }
2268 dev->fwnode = fwnode;
2269 } else {
2270 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2271 dev->fwnode->secondary : NULL;
2272 }
2273}
2274EXPORT_SYMBOL_GPL(set_primary_fwnode);
2275
2276/**
2277 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2278 * @dev: Device to handle.
2279 * @fwnode: New secondary firmware node of the device.
2280 *
2281 * If a primary firmware node of the device is present, set its secondary
2282 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2283 * @fwnode.
2284 */
2285void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2286{
2287 if (fwnode)
2288 fwnode->secondary = ERR_PTR(-ENODEV);
2289
2290 if (fwnode_is_primary(dev->fwnode))
2291 dev->fwnode->secondary = fwnode;
2292 else
2293 dev->fwnode = fwnode;
2294}