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Merge tag 'perf-urgent-for-mingo-4.10-20170117' of git://git.kernel.org/pub/scm/linux...
[mirror_ubuntu-zesty-kernel.git] / drivers / base / core.c
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
36 long sysfs_deprecated = 1;
37 #else
38 long sysfs_deprecated = 0;
39 #endif
40 static int __init sysfs_deprecated_setup(char *arg)
41 {
42 return kstrtol(arg, 10, &sysfs_deprecated);
43 }
44 early_param("sysfs.deprecated", sysfs_deprecated_setup);
45 #endif
46
47 /* Device links support. */
48
49 #ifdef CONFIG_SRCU
50 static DEFINE_MUTEX(device_links_lock);
51 DEFINE_STATIC_SRCU(device_links_srcu);
52
53 static inline void device_links_write_lock(void)
54 {
55 mutex_lock(&device_links_lock);
56 }
57
58 static inline void device_links_write_unlock(void)
59 {
60 mutex_unlock(&device_links_lock);
61 }
62
63 int device_links_read_lock(void)
64 {
65 return srcu_read_lock(&device_links_srcu);
66 }
67
68 void device_links_read_unlock(int idx)
69 {
70 srcu_read_unlock(&device_links_srcu, idx);
71 }
72 #else /* !CONFIG_SRCU */
73 static DECLARE_RWSEM(device_links_lock);
74
75 static inline void device_links_write_lock(void)
76 {
77 down_write(&device_links_lock);
78 }
79
80 static inline void device_links_write_unlock(void)
81 {
82 up_write(&device_links_lock);
83 }
84
85 int device_links_read_lock(void)
86 {
87 down_read(&device_links_lock);
88 return 0;
89 }
90
91 void device_links_read_unlock(int not_used)
92 {
93 up_read(&device_links_lock);
94 }
95 #endif /* !CONFIG_SRCU */
96
97 /**
98 * device_is_dependent - Check if one device depends on another one
99 * @dev: Device to check dependencies for.
100 * @target: Device to check against.
101 *
102 * Check if @target depends on @dev or any device dependent on it (its child or
103 * its consumer etc). Return 1 if that is the case or 0 otherwise.
104 */
105 static int device_is_dependent(struct device *dev, void *target)
106 {
107 struct device_link *link;
108 int ret;
109
110 if (WARN_ON(dev == target))
111 return 1;
112
113 ret = device_for_each_child(dev, target, device_is_dependent);
114 if (ret)
115 return ret;
116
117 list_for_each_entry(link, &dev->links.consumers, s_node) {
118 if (WARN_ON(link->consumer == target))
119 return 1;
120
121 ret = device_is_dependent(link->consumer, target);
122 if (ret)
123 break;
124 }
125 return ret;
126 }
127
128 static int device_reorder_to_tail(struct device *dev, void *not_used)
129 {
130 struct device_link *link;
131
132 /*
133 * Devices that have not been registered yet will be put to the ends
134 * of the lists during the registration, so skip them here.
135 */
136 if (device_is_registered(dev))
137 devices_kset_move_last(dev);
138
139 if (device_pm_initialized(dev))
140 device_pm_move_last(dev);
141
142 device_for_each_child(dev, NULL, device_reorder_to_tail);
143 list_for_each_entry(link, &dev->links.consumers, s_node)
144 device_reorder_to_tail(link->consumer, NULL);
145
146 return 0;
147 }
148
149 /**
150 * device_link_add - Create a link between two devices.
151 * @consumer: Consumer end of the link.
152 * @supplier: Supplier end of the link.
153 * @flags: Link flags.
154 *
155 * The caller is responsible for the proper synchronization of the link creation
156 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
157 * runtime PM framework to take the link into account. Second, if the
158 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
159 * be forced into the active metastate and reference-counted upon the creation
160 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
161 * ignored.
162 *
163 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
164 * when the consumer device driver unbinds from it. The combination of both
165 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
166 * to be returned.
167 *
168 * A side effect of the link creation is re-ordering of dpm_list and the
169 * devices_kset list by moving the consumer device and all devices depending
170 * on it to the ends of these lists (that does not happen to devices that have
171 * not been registered when this function is called).
172 *
173 * The supplier device is required to be registered when this function is called
174 * and NULL will be returned if that is not the case. The consumer device need
175 * not be registered, however.
176 */
177 struct device_link *device_link_add(struct device *consumer,
178 struct device *supplier, u32 flags)
179 {
180 struct device_link *link;
181
182 if (!consumer || !supplier ||
183 ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE)))
184 return NULL;
185
186 device_links_write_lock();
187 device_pm_lock();
188
189 /*
190 * If the supplier has not been fully registered yet or there is a
191 * reverse dependency between the consumer and the supplier already in
192 * the graph, return NULL.
193 */
194 if (!device_pm_initialized(supplier)
195 || device_is_dependent(consumer, supplier)) {
196 link = NULL;
197 goto out;
198 }
199
200 list_for_each_entry(link, &supplier->links.consumers, s_node)
201 if (link->consumer == consumer)
202 goto out;
203
204 link = kzalloc(sizeof(*link), GFP_KERNEL);
205 if (!link)
206 goto out;
207
208 if (flags & DL_FLAG_PM_RUNTIME) {
209 if (flags & DL_FLAG_RPM_ACTIVE) {
210 if (pm_runtime_get_sync(supplier) < 0) {
211 pm_runtime_put_noidle(supplier);
212 kfree(link);
213 link = NULL;
214 goto out;
215 }
216 link->rpm_active = true;
217 }
218 pm_runtime_new_link(consumer);
219 }
220 get_device(supplier);
221 link->supplier = supplier;
222 INIT_LIST_HEAD(&link->s_node);
223 get_device(consumer);
224 link->consumer = consumer;
225 INIT_LIST_HEAD(&link->c_node);
226 link->flags = flags;
227
228 /* Determine the initial link state. */
229 if (flags & DL_FLAG_STATELESS) {
230 link->status = DL_STATE_NONE;
231 } else {
232 switch (supplier->links.status) {
233 case DL_DEV_DRIVER_BOUND:
234 switch (consumer->links.status) {
235 case DL_DEV_PROBING:
236 /*
237 * Balance the decrementation of the supplier's
238 * runtime PM usage counter after consumer probe
239 * in driver_probe_device().
240 */
241 if (flags & DL_FLAG_PM_RUNTIME)
242 pm_runtime_get_sync(supplier);
243
244 link->status = DL_STATE_CONSUMER_PROBE;
245 break;
246 case DL_DEV_DRIVER_BOUND:
247 link->status = DL_STATE_ACTIVE;
248 break;
249 default:
250 link->status = DL_STATE_AVAILABLE;
251 break;
252 }
253 break;
254 case DL_DEV_UNBINDING:
255 link->status = DL_STATE_SUPPLIER_UNBIND;
256 break;
257 default:
258 link->status = DL_STATE_DORMANT;
259 break;
260 }
261 }
262
263 /*
264 * Move the consumer and all of the devices depending on it to the end
265 * of dpm_list and the devices_kset list.
266 *
267 * It is necessary to hold dpm_list locked throughout all that or else
268 * we may end up suspending with a wrong ordering of it.
269 */
270 device_reorder_to_tail(consumer, NULL);
271
272 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
273 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
274
275 dev_info(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
276
277 out:
278 device_pm_unlock();
279 device_links_write_unlock();
280 return link;
281 }
282 EXPORT_SYMBOL_GPL(device_link_add);
283
284 static void device_link_free(struct device_link *link)
285 {
286 put_device(link->consumer);
287 put_device(link->supplier);
288 kfree(link);
289 }
290
291 #ifdef CONFIG_SRCU
292 static void __device_link_free_srcu(struct rcu_head *rhead)
293 {
294 device_link_free(container_of(rhead, struct device_link, rcu_head));
295 }
296
297 static void __device_link_del(struct device_link *link)
298 {
299 dev_info(link->consumer, "Dropping the link to %s\n",
300 dev_name(link->supplier));
301
302 if (link->flags & DL_FLAG_PM_RUNTIME)
303 pm_runtime_drop_link(link->consumer);
304
305 list_del_rcu(&link->s_node);
306 list_del_rcu(&link->c_node);
307 call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
308 }
309 #else /* !CONFIG_SRCU */
310 static void __device_link_del(struct device_link *link)
311 {
312 dev_info(link->consumer, "Dropping the link to %s\n",
313 dev_name(link->supplier));
314
315 list_del(&link->s_node);
316 list_del(&link->c_node);
317 device_link_free(link);
318 }
319 #endif /* !CONFIG_SRCU */
320
321 /**
322 * device_link_del - Delete a link between two devices.
323 * @link: Device link to delete.
324 *
325 * The caller must ensure proper synchronization of this function with runtime
326 * PM.
327 */
328 void device_link_del(struct device_link *link)
329 {
330 device_links_write_lock();
331 device_pm_lock();
332 __device_link_del(link);
333 device_pm_unlock();
334 device_links_write_unlock();
335 }
336 EXPORT_SYMBOL_GPL(device_link_del);
337
338 static void device_links_missing_supplier(struct device *dev)
339 {
340 struct device_link *link;
341
342 list_for_each_entry(link, &dev->links.suppliers, c_node)
343 if (link->status == DL_STATE_CONSUMER_PROBE)
344 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
345 }
346
347 /**
348 * device_links_check_suppliers - Check presence of supplier drivers.
349 * @dev: Consumer device.
350 *
351 * Check links from this device to any suppliers. Walk the list of the device's
352 * links to suppliers and see if all of them are available. If not, simply
353 * return -EPROBE_DEFER.
354 *
355 * We need to guarantee that the supplier will not go away after the check has
356 * been positive here. It only can go away in __device_release_driver() and
357 * that function checks the device's links to consumers. This means we need to
358 * mark the link as "consumer probe in progress" to make the supplier removal
359 * wait for us to complete (or bad things may happen).
360 *
361 * Links with the DL_FLAG_STATELESS flag set are ignored.
362 */
363 int device_links_check_suppliers(struct device *dev)
364 {
365 struct device_link *link;
366 int ret = 0;
367
368 device_links_write_lock();
369
370 list_for_each_entry(link, &dev->links.suppliers, c_node) {
371 if (link->flags & DL_FLAG_STATELESS)
372 continue;
373
374 if (link->status != DL_STATE_AVAILABLE) {
375 device_links_missing_supplier(dev);
376 ret = -EPROBE_DEFER;
377 break;
378 }
379 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
380 }
381 dev->links.status = DL_DEV_PROBING;
382
383 device_links_write_unlock();
384 return ret;
385 }
386
387 /**
388 * device_links_driver_bound - Update device links after probing its driver.
389 * @dev: Device to update the links for.
390 *
391 * The probe has been successful, so update links from this device to any
392 * consumers by changing their status to "available".
393 *
394 * Also change the status of @dev's links to suppliers to "active".
395 *
396 * Links with the DL_FLAG_STATELESS flag set are ignored.
397 */
398 void device_links_driver_bound(struct device *dev)
399 {
400 struct device_link *link;
401
402 device_links_write_lock();
403
404 list_for_each_entry(link, &dev->links.consumers, s_node) {
405 if (link->flags & DL_FLAG_STATELESS)
406 continue;
407
408 WARN_ON(link->status != DL_STATE_DORMANT);
409 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
410 }
411
412 list_for_each_entry(link, &dev->links.suppliers, c_node) {
413 if (link->flags & DL_FLAG_STATELESS)
414 continue;
415
416 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
417 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
418 }
419
420 dev->links.status = DL_DEV_DRIVER_BOUND;
421
422 device_links_write_unlock();
423 }
424
425 /**
426 * __device_links_no_driver - Update links of a device without a driver.
427 * @dev: Device without a drvier.
428 *
429 * Delete all non-persistent links from this device to any suppliers.
430 *
431 * Persistent links stay around, but their status is changed to "available",
432 * unless they already are in the "supplier unbind in progress" state in which
433 * case they need not be updated.
434 *
435 * Links with the DL_FLAG_STATELESS flag set are ignored.
436 */
437 static void __device_links_no_driver(struct device *dev)
438 {
439 struct device_link *link, *ln;
440
441 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
442 if (link->flags & DL_FLAG_STATELESS)
443 continue;
444
445 if (link->flags & DL_FLAG_AUTOREMOVE)
446 __device_link_del(link);
447 else if (link->status != DL_STATE_SUPPLIER_UNBIND)
448 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
449 }
450
451 dev->links.status = DL_DEV_NO_DRIVER;
452 }
453
454 void device_links_no_driver(struct device *dev)
455 {
456 device_links_write_lock();
457 __device_links_no_driver(dev);
458 device_links_write_unlock();
459 }
460
461 /**
462 * device_links_driver_cleanup - Update links after driver removal.
463 * @dev: Device whose driver has just gone away.
464 *
465 * Update links to consumers for @dev by changing their status to "dormant" and
466 * invoke %__device_links_no_driver() to update links to suppliers for it as
467 * appropriate.
468 *
469 * Links with the DL_FLAG_STATELESS flag set are ignored.
470 */
471 void device_links_driver_cleanup(struct device *dev)
472 {
473 struct device_link *link;
474
475 device_links_write_lock();
476
477 list_for_each_entry(link, &dev->links.consumers, s_node) {
478 if (link->flags & DL_FLAG_STATELESS)
479 continue;
480
481 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE);
482 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
483 WRITE_ONCE(link->status, DL_STATE_DORMANT);
484 }
485
486 __device_links_no_driver(dev);
487
488 device_links_write_unlock();
489 }
490
491 /**
492 * device_links_busy - Check if there are any busy links to consumers.
493 * @dev: Device to check.
494 *
495 * Check each consumer of the device and return 'true' if its link's status
496 * is one of "consumer probe" or "active" (meaning that the given consumer is
497 * probing right now or its driver is present). Otherwise, change the link
498 * state to "supplier unbind" to prevent the consumer from being probed
499 * successfully going forward.
500 *
501 * Return 'false' if there are no probing or active consumers.
502 *
503 * Links with the DL_FLAG_STATELESS flag set are ignored.
504 */
505 bool device_links_busy(struct device *dev)
506 {
507 struct device_link *link;
508 bool ret = false;
509
510 device_links_write_lock();
511
512 list_for_each_entry(link, &dev->links.consumers, s_node) {
513 if (link->flags & DL_FLAG_STATELESS)
514 continue;
515
516 if (link->status == DL_STATE_CONSUMER_PROBE
517 || link->status == DL_STATE_ACTIVE) {
518 ret = true;
519 break;
520 }
521 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
522 }
523
524 dev->links.status = DL_DEV_UNBINDING;
525
526 device_links_write_unlock();
527 return ret;
528 }
529
530 /**
531 * device_links_unbind_consumers - Force unbind consumers of the given device.
532 * @dev: Device to unbind the consumers of.
533 *
534 * Walk the list of links to consumers for @dev and if any of them is in the
535 * "consumer probe" state, wait for all device probes in progress to complete
536 * and start over.
537 *
538 * If that's not the case, change the status of the link to "supplier unbind"
539 * and check if the link was in the "active" state. If so, force the consumer
540 * driver to unbind and start over (the consumer will not re-probe as we have
541 * changed the state of the link already).
542 *
543 * Links with the DL_FLAG_STATELESS flag set are ignored.
544 */
545 void device_links_unbind_consumers(struct device *dev)
546 {
547 struct device_link *link;
548
549 start:
550 device_links_write_lock();
551
552 list_for_each_entry(link, &dev->links.consumers, s_node) {
553 enum device_link_state status;
554
555 if (link->flags & DL_FLAG_STATELESS)
556 continue;
557
558 status = link->status;
559 if (status == DL_STATE_CONSUMER_PROBE) {
560 device_links_write_unlock();
561
562 wait_for_device_probe();
563 goto start;
564 }
565 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
566 if (status == DL_STATE_ACTIVE) {
567 struct device *consumer = link->consumer;
568
569 get_device(consumer);
570
571 device_links_write_unlock();
572
573 device_release_driver_internal(consumer, NULL,
574 consumer->parent);
575 put_device(consumer);
576 goto start;
577 }
578 }
579
580 device_links_write_unlock();
581 }
582
583 /**
584 * device_links_purge - Delete existing links to other devices.
585 * @dev: Target device.
586 */
587 static void device_links_purge(struct device *dev)
588 {
589 struct device_link *link, *ln;
590
591 /*
592 * Delete all of the remaining links from this device to any other
593 * devices (either consumers or suppliers).
594 */
595 device_links_write_lock();
596
597 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
598 WARN_ON(link->status == DL_STATE_ACTIVE);
599 __device_link_del(link);
600 }
601
602 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
603 WARN_ON(link->status != DL_STATE_DORMANT &&
604 link->status != DL_STATE_NONE);
605 __device_link_del(link);
606 }
607
608 device_links_write_unlock();
609 }
610
611 /* Device links support end. */
612
613 int (*platform_notify)(struct device *dev) = NULL;
614 int (*platform_notify_remove)(struct device *dev) = NULL;
615 static struct kobject *dev_kobj;
616 struct kobject *sysfs_dev_char_kobj;
617 struct kobject *sysfs_dev_block_kobj;
618
619 static DEFINE_MUTEX(device_hotplug_lock);
620
621 void lock_device_hotplug(void)
622 {
623 mutex_lock(&device_hotplug_lock);
624 }
625
626 void unlock_device_hotplug(void)
627 {
628 mutex_unlock(&device_hotplug_lock);
629 }
630
631 int lock_device_hotplug_sysfs(void)
632 {
633 if (mutex_trylock(&device_hotplug_lock))
634 return 0;
635
636 /* Avoid busy looping (5 ms of sleep should do). */
637 msleep(5);
638 return restart_syscall();
639 }
640
641 #ifdef CONFIG_BLOCK
642 static inline int device_is_not_partition(struct device *dev)
643 {
644 return !(dev->type == &part_type);
645 }
646 #else
647 static inline int device_is_not_partition(struct device *dev)
648 {
649 return 1;
650 }
651 #endif
652
653 /**
654 * dev_driver_string - Return a device's driver name, if at all possible
655 * @dev: struct device to get the name of
656 *
657 * Will return the device's driver's name if it is bound to a device. If
658 * the device is not bound to a driver, it will return the name of the bus
659 * it is attached to. If it is not attached to a bus either, an empty
660 * string will be returned.
661 */
662 const char *dev_driver_string(const struct device *dev)
663 {
664 struct device_driver *drv;
665
666 /* dev->driver can change to NULL underneath us because of unbinding,
667 * so be careful about accessing it. dev->bus and dev->class should
668 * never change once they are set, so they don't need special care.
669 */
670 drv = ACCESS_ONCE(dev->driver);
671 return drv ? drv->name :
672 (dev->bus ? dev->bus->name :
673 (dev->class ? dev->class->name : ""));
674 }
675 EXPORT_SYMBOL(dev_driver_string);
676
677 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
678
679 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
680 char *buf)
681 {
682 struct device_attribute *dev_attr = to_dev_attr(attr);
683 struct device *dev = kobj_to_dev(kobj);
684 ssize_t ret = -EIO;
685
686 if (dev_attr->show)
687 ret = dev_attr->show(dev, dev_attr, buf);
688 if (ret >= (ssize_t)PAGE_SIZE) {
689 print_symbol("dev_attr_show: %s returned bad count\n",
690 (unsigned long)dev_attr->show);
691 }
692 return ret;
693 }
694
695 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
696 const char *buf, size_t count)
697 {
698 struct device_attribute *dev_attr = to_dev_attr(attr);
699 struct device *dev = kobj_to_dev(kobj);
700 ssize_t ret = -EIO;
701
702 if (dev_attr->store)
703 ret = dev_attr->store(dev, dev_attr, buf, count);
704 return ret;
705 }
706
707 static const struct sysfs_ops dev_sysfs_ops = {
708 .show = dev_attr_show,
709 .store = dev_attr_store,
710 };
711
712 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
713
714 ssize_t device_store_ulong(struct device *dev,
715 struct device_attribute *attr,
716 const char *buf, size_t size)
717 {
718 struct dev_ext_attribute *ea = to_ext_attr(attr);
719 char *end;
720 unsigned long new = simple_strtoul(buf, &end, 0);
721 if (end == buf)
722 return -EINVAL;
723 *(unsigned long *)(ea->var) = new;
724 /* Always return full write size even if we didn't consume all */
725 return size;
726 }
727 EXPORT_SYMBOL_GPL(device_store_ulong);
728
729 ssize_t device_show_ulong(struct device *dev,
730 struct device_attribute *attr,
731 char *buf)
732 {
733 struct dev_ext_attribute *ea = to_ext_attr(attr);
734 return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
735 }
736 EXPORT_SYMBOL_GPL(device_show_ulong);
737
738 ssize_t device_store_int(struct device *dev,
739 struct device_attribute *attr,
740 const char *buf, size_t size)
741 {
742 struct dev_ext_attribute *ea = to_ext_attr(attr);
743 char *end;
744 long new = simple_strtol(buf, &end, 0);
745 if (end == buf || new > INT_MAX || new < INT_MIN)
746 return -EINVAL;
747 *(int *)(ea->var) = new;
748 /* Always return full write size even if we didn't consume all */
749 return size;
750 }
751 EXPORT_SYMBOL_GPL(device_store_int);
752
753 ssize_t device_show_int(struct device *dev,
754 struct device_attribute *attr,
755 char *buf)
756 {
757 struct dev_ext_attribute *ea = to_ext_attr(attr);
758
759 return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
760 }
761 EXPORT_SYMBOL_GPL(device_show_int);
762
763 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
764 const char *buf, size_t size)
765 {
766 struct dev_ext_attribute *ea = to_ext_attr(attr);
767
768 if (strtobool(buf, ea->var) < 0)
769 return -EINVAL;
770
771 return size;
772 }
773 EXPORT_SYMBOL_GPL(device_store_bool);
774
775 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
776 char *buf)
777 {
778 struct dev_ext_attribute *ea = to_ext_attr(attr);
779
780 return snprintf(buf, PAGE_SIZE, "%d\n", *(bool *)(ea->var));
781 }
782 EXPORT_SYMBOL_GPL(device_show_bool);
783
784 /**
785 * device_release - free device structure.
786 * @kobj: device's kobject.
787 *
788 * This is called once the reference count for the object
789 * reaches 0. We forward the call to the device's release
790 * method, which should handle actually freeing the structure.
791 */
792 static void device_release(struct kobject *kobj)
793 {
794 struct device *dev = kobj_to_dev(kobj);
795 struct device_private *p = dev->p;
796
797 /*
798 * Some platform devices are driven without driver attached
799 * and managed resources may have been acquired. Make sure
800 * all resources are released.
801 *
802 * Drivers still can add resources into device after device
803 * is deleted but alive, so release devres here to avoid
804 * possible memory leak.
805 */
806 devres_release_all(dev);
807
808 if (dev->release)
809 dev->release(dev);
810 else if (dev->type && dev->type->release)
811 dev->type->release(dev);
812 else if (dev->class && dev->class->dev_release)
813 dev->class->dev_release(dev);
814 else
815 WARN(1, KERN_ERR "Device '%s' does not have a release() "
816 "function, it is broken and must be fixed.\n",
817 dev_name(dev));
818 kfree(p);
819 }
820
821 static const void *device_namespace(struct kobject *kobj)
822 {
823 struct device *dev = kobj_to_dev(kobj);
824 const void *ns = NULL;
825
826 if (dev->class && dev->class->ns_type)
827 ns = dev->class->namespace(dev);
828
829 return ns;
830 }
831
832 static struct kobj_type device_ktype = {
833 .release = device_release,
834 .sysfs_ops = &dev_sysfs_ops,
835 .namespace = device_namespace,
836 };
837
838
839 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
840 {
841 struct kobj_type *ktype = get_ktype(kobj);
842
843 if (ktype == &device_ktype) {
844 struct device *dev = kobj_to_dev(kobj);
845 if (dev->bus)
846 return 1;
847 if (dev->class)
848 return 1;
849 }
850 return 0;
851 }
852
853 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
854 {
855 struct device *dev = kobj_to_dev(kobj);
856
857 if (dev->bus)
858 return dev->bus->name;
859 if (dev->class)
860 return dev->class->name;
861 return NULL;
862 }
863
864 static int dev_uevent(struct kset *kset, struct kobject *kobj,
865 struct kobj_uevent_env *env)
866 {
867 struct device *dev = kobj_to_dev(kobj);
868 int retval = 0;
869
870 /* add device node properties if present */
871 if (MAJOR(dev->devt)) {
872 const char *tmp;
873 const char *name;
874 umode_t mode = 0;
875 kuid_t uid = GLOBAL_ROOT_UID;
876 kgid_t gid = GLOBAL_ROOT_GID;
877
878 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
879 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
880 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
881 if (name) {
882 add_uevent_var(env, "DEVNAME=%s", name);
883 if (mode)
884 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
885 if (!uid_eq(uid, GLOBAL_ROOT_UID))
886 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
887 if (!gid_eq(gid, GLOBAL_ROOT_GID))
888 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
889 kfree(tmp);
890 }
891 }
892
893 if (dev->type && dev->type->name)
894 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
895
896 if (dev->driver)
897 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
898
899 /* Add common DT information about the device */
900 of_device_uevent(dev, env);
901
902 /* have the bus specific function add its stuff */
903 if (dev->bus && dev->bus->uevent) {
904 retval = dev->bus->uevent(dev, env);
905 if (retval)
906 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
907 dev_name(dev), __func__, retval);
908 }
909
910 /* have the class specific function add its stuff */
911 if (dev->class && dev->class->dev_uevent) {
912 retval = dev->class->dev_uevent(dev, env);
913 if (retval)
914 pr_debug("device: '%s': %s: class uevent() "
915 "returned %d\n", dev_name(dev),
916 __func__, retval);
917 }
918
919 /* have the device type specific function add its stuff */
920 if (dev->type && dev->type->uevent) {
921 retval = dev->type->uevent(dev, env);
922 if (retval)
923 pr_debug("device: '%s': %s: dev_type uevent() "
924 "returned %d\n", dev_name(dev),
925 __func__, retval);
926 }
927
928 return retval;
929 }
930
931 static const struct kset_uevent_ops device_uevent_ops = {
932 .filter = dev_uevent_filter,
933 .name = dev_uevent_name,
934 .uevent = dev_uevent,
935 };
936
937 static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
938 char *buf)
939 {
940 struct kobject *top_kobj;
941 struct kset *kset;
942 struct kobj_uevent_env *env = NULL;
943 int i;
944 size_t count = 0;
945 int retval;
946
947 /* search the kset, the device belongs to */
948 top_kobj = &dev->kobj;
949 while (!top_kobj->kset && top_kobj->parent)
950 top_kobj = top_kobj->parent;
951 if (!top_kobj->kset)
952 goto out;
953
954 kset = top_kobj->kset;
955 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
956 goto out;
957
958 /* respect filter */
959 if (kset->uevent_ops && kset->uevent_ops->filter)
960 if (!kset->uevent_ops->filter(kset, &dev->kobj))
961 goto out;
962
963 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
964 if (!env)
965 return -ENOMEM;
966
967 /* let the kset specific function add its keys */
968 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
969 if (retval)
970 goto out;
971
972 /* copy keys to file */
973 for (i = 0; i < env->envp_idx; i++)
974 count += sprintf(&buf[count], "%s\n", env->envp[i]);
975 out:
976 kfree(env);
977 return count;
978 }
979
980 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
981 const char *buf, size_t count)
982 {
983 enum kobject_action action;
984
985 if (kobject_action_type(buf, count, &action) == 0)
986 kobject_uevent(&dev->kobj, action);
987 else
988 dev_err(dev, "uevent: unknown action-string\n");
989 return count;
990 }
991 static DEVICE_ATTR_RW(uevent);
992
993 static ssize_t online_show(struct device *dev, struct device_attribute *attr,
994 char *buf)
995 {
996 bool val;
997
998 device_lock(dev);
999 val = !dev->offline;
1000 device_unlock(dev);
1001 return sprintf(buf, "%u\n", val);
1002 }
1003
1004 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
1005 const char *buf, size_t count)
1006 {
1007 bool val;
1008 int ret;
1009
1010 ret = strtobool(buf, &val);
1011 if (ret < 0)
1012 return ret;
1013
1014 ret = lock_device_hotplug_sysfs();
1015 if (ret)
1016 return ret;
1017
1018 ret = val ? device_online(dev) : device_offline(dev);
1019 unlock_device_hotplug();
1020 return ret < 0 ? ret : count;
1021 }
1022 static DEVICE_ATTR_RW(online);
1023
1024 int device_add_groups(struct device *dev, const struct attribute_group **groups)
1025 {
1026 return sysfs_create_groups(&dev->kobj, groups);
1027 }
1028
1029 void device_remove_groups(struct device *dev,
1030 const struct attribute_group **groups)
1031 {
1032 sysfs_remove_groups(&dev->kobj, groups);
1033 }
1034
1035 static int device_add_attrs(struct device *dev)
1036 {
1037 struct class *class = dev->class;
1038 const struct device_type *type = dev->type;
1039 int error;
1040
1041 if (class) {
1042 error = device_add_groups(dev, class->dev_groups);
1043 if (error)
1044 return error;
1045 }
1046
1047 if (type) {
1048 error = device_add_groups(dev, type->groups);
1049 if (error)
1050 goto err_remove_class_groups;
1051 }
1052
1053 error = device_add_groups(dev, dev->groups);
1054 if (error)
1055 goto err_remove_type_groups;
1056
1057 if (device_supports_offline(dev) && !dev->offline_disabled) {
1058 error = device_create_file(dev, &dev_attr_online);
1059 if (error)
1060 goto err_remove_dev_groups;
1061 }
1062
1063 return 0;
1064
1065 err_remove_dev_groups:
1066 device_remove_groups(dev, dev->groups);
1067 err_remove_type_groups:
1068 if (type)
1069 device_remove_groups(dev, type->groups);
1070 err_remove_class_groups:
1071 if (class)
1072 device_remove_groups(dev, class->dev_groups);
1073
1074 return error;
1075 }
1076
1077 static void device_remove_attrs(struct device *dev)
1078 {
1079 struct class *class = dev->class;
1080 const struct device_type *type = dev->type;
1081
1082 device_remove_file(dev, &dev_attr_online);
1083 device_remove_groups(dev, dev->groups);
1084
1085 if (type)
1086 device_remove_groups(dev, type->groups);
1087
1088 if (class)
1089 device_remove_groups(dev, class->dev_groups);
1090 }
1091
1092 static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
1093 char *buf)
1094 {
1095 return print_dev_t(buf, dev->devt);
1096 }
1097 static DEVICE_ATTR_RO(dev);
1098
1099 /* /sys/devices/ */
1100 struct kset *devices_kset;
1101
1102 /**
1103 * devices_kset_move_before - Move device in the devices_kset's list.
1104 * @deva: Device to move.
1105 * @devb: Device @deva should come before.
1106 */
1107 static void devices_kset_move_before(struct device *deva, struct device *devb)
1108 {
1109 if (!devices_kset)
1110 return;
1111 pr_debug("devices_kset: Moving %s before %s\n",
1112 dev_name(deva), dev_name(devb));
1113 spin_lock(&devices_kset->list_lock);
1114 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
1115 spin_unlock(&devices_kset->list_lock);
1116 }
1117
1118 /**
1119 * devices_kset_move_after - Move device in the devices_kset's list.
1120 * @deva: Device to move
1121 * @devb: Device @deva should come after.
1122 */
1123 static void devices_kset_move_after(struct device *deva, struct device *devb)
1124 {
1125 if (!devices_kset)
1126 return;
1127 pr_debug("devices_kset: Moving %s after %s\n",
1128 dev_name(deva), dev_name(devb));
1129 spin_lock(&devices_kset->list_lock);
1130 list_move(&deva->kobj.entry, &devb->kobj.entry);
1131 spin_unlock(&devices_kset->list_lock);
1132 }
1133
1134 /**
1135 * devices_kset_move_last - move the device to the end of devices_kset's list.
1136 * @dev: device to move
1137 */
1138 void devices_kset_move_last(struct device *dev)
1139 {
1140 if (!devices_kset)
1141 return;
1142 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
1143 spin_lock(&devices_kset->list_lock);
1144 list_move_tail(&dev->kobj.entry, &devices_kset->list);
1145 spin_unlock(&devices_kset->list_lock);
1146 }
1147
1148 /**
1149 * device_create_file - create sysfs attribute file for device.
1150 * @dev: device.
1151 * @attr: device attribute descriptor.
1152 */
1153 int device_create_file(struct device *dev,
1154 const struct device_attribute *attr)
1155 {
1156 int error = 0;
1157
1158 if (dev) {
1159 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
1160 "Attribute %s: write permission without 'store'\n",
1161 attr->attr.name);
1162 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
1163 "Attribute %s: read permission without 'show'\n",
1164 attr->attr.name);
1165 error = sysfs_create_file(&dev->kobj, &attr->attr);
1166 }
1167
1168 return error;
1169 }
1170 EXPORT_SYMBOL_GPL(device_create_file);
1171
1172 /**
1173 * device_remove_file - remove sysfs attribute file.
1174 * @dev: device.
1175 * @attr: device attribute descriptor.
1176 */
1177 void device_remove_file(struct device *dev,
1178 const struct device_attribute *attr)
1179 {
1180 if (dev)
1181 sysfs_remove_file(&dev->kobj, &attr->attr);
1182 }
1183 EXPORT_SYMBOL_GPL(device_remove_file);
1184
1185 /**
1186 * device_remove_file_self - remove sysfs attribute file from its own method.
1187 * @dev: device.
1188 * @attr: device attribute descriptor.
1189 *
1190 * See kernfs_remove_self() for details.
1191 */
1192 bool device_remove_file_self(struct device *dev,
1193 const struct device_attribute *attr)
1194 {
1195 if (dev)
1196 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
1197 else
1198 return false;
1199 }
1200 EXPORT_SYMBOL_GPL(device_remove_file_self);
1201
1202 /**
1203 * device_create_bin_file - create sysfs binary attribute file for device.
1204 * @dev: device.
1205 * @attr: device binary attribute descriptor.
1206 */
1207 int device_create_bin_file(struct device *dev,
1208 const struct bin_attribute *attr)
1209 {
1210 int error = -EINVAL;
1211 if (dev)
1212 error = sysfs_create_bin_file(&dev->kobj, attr);
1213 return error;
1214 }
1215 EXPORT_SYMBOL_GPL(device_create_bin_file);
1216
1217 /**
1218 * device_remove_bin_file - remove sysfs binary attribute file
1219 * @dev: device.
1220 * @attr: device binary attribute descriptor.
1221 */
1222 void device_remove_bin_file(struct device *dev,
1223 const struct bin_attribute *attr)
1224 {
1225 if (dev)
1226 sysfs_remove_bin_file(&dev->kobj, attr);
1227 }
1228 EXPORT_SYMBOL_GPL(device_remove_bin_file);
1229
1230 static void klist_children_get(struct klist_node *n)
1231 {
1232 struct device_private *p = to_device_private_parent(n);
1233 struct device *dev = p->device;
1234
1235 get_device(dev);
1236 }
1237
1238 static void klist_children_put(struct klist_node *n)
1239 {
1240 struct device_private *p = to_device_private_parent(n);
1241 struct device *dev = p->device;
1242
1243 put_device(dev);
1244 }
1245
1246 /**
1247 * device_initialize - init device structure.
1248 * @dev: device.
1249 *
1250 * This prepares the device for use by other layers by initializing
1251 * its fields.
1252 * It is the first half of device_register(), if called by
1253 * that function, though it can also be called separately, so one
1254 * may use @dev's fields. In particular, get_device()/put_device()
1255 * may be used for reference counting of @dev after calling this
1256 * function.
1257 *
1258 * All fields in @dev must be initialized by the caller to 0, except
1259 * for those explicitly set to some other value. The simplest
1260 * approach is to use kzalloc() to allocate the structure containing
1261 * @dev.
1262 *
1263 * NOTE: Use put_device() to give up your reference instead of freeing
1264 * @dev directly once you have called this function.
1265 */
1266 void device_initialize(struct device *dev)
1267 {
1268 dev->kobj.kset = devices_kset;
1269 kobject_init(&dev->kobj, &device_ktype);
1270 INIT_LIST_HEAD(&dev->dma_pools);
1271 mutex_init(&dev->mutex);
1272 lockdep_set_novalidate_class(&dev->mutex);
1273 spin_lock_init(&dev->devres_lock);
1274 INIT_LIST_HEAD(&dev->devres_head);
1275 device_pm_init(dev);
1276 set_dev_node(dev, -1);
1277 #ifdef CONFIG_GENERIC_MSI_IRQ
1278 INIT_LIST_HEAD(&dev->msi_list);
1279 #endif
1280 INIT_LIST_HEAD(&dev->links.consumers);
1281 INIT_LIST_HEAD(&dev->links.suppliers);
1282 dev->links.status = DL_DEV_NO_DRIVER;
1283 }
1284 EXPORT_SYMBOL_GPL(device_initialize);
1285
1286 struct kobject *virtual_device_parent(struct device *dev)
1287 {
1288 static struct kobject *virtual_dir = NULL;
1289
1290 if (!virtual_dir)
1291 virtual_dir = kobject_create_and_add("virtual",
1292 &devices_kset->kobj);
1293
1294 return virtual_dir;
1295 }
1296
1297 struct class_dir {
1298 struct kobject kobj;
1299 struct class *class;
1300 };
1301
1302 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1303
1304 static void class_dir_release(struct kobject *kobj)
1305 {
1306 struct class_dir *dir = to_class_dir(kobj);
1307 kfree(dir);
1308 }
1309
1310 static const
1311 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
1312 {
1313 struct class_dir *dir = to_class_dir(kobj);
1314 return dir->class->ns_type;
1315 }
1316
1317 static struct kobj_type class_dir_ktype = {
1318 .release = class_dir_release,
1319 .sysfs_ops = &kobj_sysfs_ops,
1320 .child_ns_type = class_dir_child_ns_type
1321 };
1322
1323 static struct kobject *
1324 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
1325 {
1326 struct class_dir *dir;
1327 int retval;
1328
1329 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
1330 if (!dir)
1331 return NULL;
1332
1333 dir->class = class;
1334 kobject_init(&dir->kobj, &class_dir_ktype);
1335
1336 dir->kobj.kset = &class->p->glue_dirs;
1337
1338 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
1339 if (retval < 0) {
1340 kobject_put(&dir->kobj);
1341 return NULL;
1342 }
1343 return &dir->kobj;
1344 }
1345
1346 static DEFINE_MUTEX(gdp_mutex);
1347
1348 static struct kobject *get_device_parent(struct device *dev,
1349 struct device *parent)
1350 {
1351 if (dev->class) {
1352 struct kobject *kobj = NULL;
1353 struct kobject *parent_kobj;
1354 struct kobject *k;
1355
1356 #ifdef CONFIG_BLOCK
1357 /* block disks show up in /sys/block */
1358 if (sysfs_deprecated && dev->class == &block_class) {
1359 if (parent && parent->class == &block_class)
1360 return &parent->kobj;
1361 return &block_class.p->subsys.kobj;
1362 }
1363 #endif
1364
1365 /*
1366 * If we have no parent, we live in "virtual".
1367 * Class-devices with a non class-device as parent, live
1368 * in a "glue" directory to prevent namespace collisions.
1369 */
1370 if (parent == NULL)
1371 parent_kobj = virtual_device_parent(dev);
1372 else if (parent->class && !dev->class->ns_type)
1373 return &parent->kobj;
1374 else
1375 parent_kobj = &parent->kobj;
1376
1377 mutex_lock(&gdp_mutex);
1378
1379 /* find our class-directory at the parent and reference it */
1380 spin_lock(&dev->class->p->glue_dirs.list_lock);
1381 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
1382 if (k->parent == parent_kobj) {
1383 kobj = kobject_get(k);
1384 break;
1385 }
1386 spin_unlock(&dev->class->p->glue_dirs.list_lock);
1387 if (kobj) {
1388 mutex_unlock(&gdp_mutex);
1389 return kobj;
1390 }
1391
1392 /* or create a new class-directory at the parent device */
1393 k = class_dir_create_and_add(dev->class, parent_kobj);
1394 /* do not emit an uevent for this simple "glue" directory */
1395 mutex_unlock(&gdp_mutex);
1396 return k;
1397 }
1398
1399 /* subsystems can specify a default root directory for their devices */
1400 if (!parent && dev->bus && dev->bus->dev_root)
1401 return &dev->bus->dev_root->kobj;
1402
1403 if (parent)
1404 return &parent->kobj;
1405 return NULL;
1406 }
1407
1408 static inline bool live_in_glue_dir(struct kobject *kobj,
1409 struct device *dev)
1410 {
1411 if (!kobj || !dev->class ||
1412 kobj->kset != &dev->class->p->glue_dirs)
1413 return false;
1414 return true;
1415 }
1416
1417 static inline struct kobject *get_glue_dir(struct device *dev)
1418 {
1419 return dev->kobj.parent;
1420 }
1421
1422 /*
1423 * make sure cleaning up dir as the last step, we need to make
1424 * sure .release handler of kobject is run with holding the
1425 * global lock
1426 */
1427 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
1428 {
1429 /* see if we live in a "glue" directory */
1430 if (!live_in_glue_dir(glue_dir, dev))
1431 return;
1432
1433 mutex_lock(&gdp_mutex);
1434 kobject_put(glue_dir);
1435 mutex_unlock(&gdp_mutex);
1436 }
1437
1438 static int device_add_class_symlinks(struct device *dev)
1439 {
1440 struct device_node *of_node = dev_of_node(dev);
1441 int error;
1442
1443 if (of_node) {
1444 error = sysfs_create_link(&dev->kobj, &of_node->kobj,"of_node");
1445 if (error)
1446 dev_warn(dev, "Error %d creating of_node link\n",error);
1447 /* An error here doesn't warrant bringing down the device */
1448 }
1449
1450 if (!dev->class)
1451 return 0;
1452
1453 error = sysfs_create_link(&dev->kobj,
1454 &dev->class->p->subsys.kobj,
1455 "subsystem");
1456 if (error)
1457 goto out_devnode;
1458
1459 if (dev->parent && device_is_not_partition(dev)) {
1460 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
1461 "device");
1462 if (error)
1463 goto out_subsys;
1464 }
1465
1466 #ifdef CONFIG_BLOCK
1467 /* /sys/block has directories and does not need symlinks */
1468 if (sysfs_deprecated && dev->class == &block_class)
1469 return 0;
1470 #endif
1471
1472 /* link in the class directory pointing to the device */
1473 error = sysfs_create_link(&dev->class->p->subsys.kobj,
1474 &dev->kobj, dev_name(dev));
1475 if (error)
1476 goto out_device;
1477
1478 return 0;
1479
1480 out_device:
1481 sysfs_remove_link(&dev->kobj, "device");
1482
1483 out_subsys:
1484 sysfs_remove_link(&dev->kobj, "subsystem");
1485 out_devnode:
1486 sysfs_remove_link(&dev->kobj, "of_node");
1487 return error;
1488 }
1489
1490 static void device_remove_class_symlinks(struct device *dev)
1491 {
1492 if (dev_of_node(dev))
1493 sysfs_remove_link(&dev->kobj, "of_node");
1494
1495 if (!dev->class)
1496 return;
1497
1498 if (dev->parent && device_is_not_partition(dev))
1499 sysfs_remove_link(&dev->kobj, "device");
1500 sysfs_remove_link(&dev->kobj, "subsystem");
1501 #ifdef CONFIG_BLOCK
1502 if (sysfs_deprecated && dev->class == &block_class)
1503 return;
1504 #endif
1505 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
1506 }
1507
1508 /**
1509 * dev_set_name - set a device name
1510 * @dev: device
1511 * @fmt: format string for the device's name
1512 */
1513 int dev_set_name(struct device *dev, const char *fmt, ...)
1514 {
1515 va_list vargs;
1516 int err;
1517
1518 va_start(vargs, fmt);
1519 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
1520 va_end(vargs);
1521 return err;
1522 }
1523 EXPORT_SYMBOL_GPL(dev_set_name);
1524
1525 /**
1526 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1527 * @dev: device
1528 *
1529 * By default we select char/ for new entries. Setting class->dev_obj
1530 * to NULL prevents an entry from being created. class->dev_kobj must
1531 * be set (or cleared) before any devices are registered to the class
1532 * otherwise device_create_sys_dev_entry() and
1533 * device_remove_sys_dev_entry() will disagree about the presence of
1534 * the link.
1535 */
1536 static struct kobject *device_to_dev_kobj(struct device *dev)
1537 {
1538 struct kobject *kobj;
1539
1540 if (dev->class)
1541 kobj = dev->class->dev_kobj;
1542 else
1543 kobj = sysfs_dev_char_kobj;
1544
1545 return kobj;
1546 }
1547
1548 static int device_create_sys_dev_entry(struct device *dev)
1549 {
1550 struct kobject *kobj = device_to_dev_kobj(dev);
1551 int error = 0;
1552 char devt_str[15];
1553
1554 if (kobj) {
1555 format_dev_t(devt_str, dev->devt);
1556 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
1557 }
1558
1559 return error;
1560 }
1561
1562 static void device_remove_sys_dev_entry(struct device *dev)
1563 {
1564 struct kobject *kobj = device_to_dev_kobj(dev);
1565 char devt_str[15];
1566
1567 if (kobj) {
1568 format_dev_t(devt_str, dev->devt);
1569 sysfs_remove_link(kobj, devt_str);
1570 }
1571 }
1572
1573 int device_private_init(struct device *dev)
1574 {
1575 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
1576 if (!dev->p)
1577 return -ENOMEM;
1578 dev->p->device = dev;
1579 klist_init(&dev->p->klist_children, klist_children_get,
1580 klist_children_put);
1581 INIT_LIST_HEAD(&dev->p->deferred_probe);
1582 return 0;
1583 }
1584
1585 /**
1586 * device_add - add device to device hierarchy.
1587 * @dev: device.
1588 *
1589 * This is part 2 of device_register(), though may be called
1590 * separately _iff_ device_initialize() has been called separately.
1591 *
1592 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1593 * to the global and sibling lists for the device, then
1594 * adds it to the other relevant subsystems of the driver model.
1595 *
1596 * Do not call this routine or device_register() more than once for
1597 * any device structure. The driver model core is not designed to work
1598 * with devices that get unregistered and then spring back to life.
1599 * (Among other things, it's very hard to guarantee that all references
1600 * to the previous incarnation of @dev have been dropped.) Allocate
1601 * and register a fresh new struct device instead.
1602 *
1603 * NOTE: _Never_ directly free @dev after calling this function, even
1604 * if it returned an error! Always use put_device() to give up your
1605 * reference instead.
1606 */
1607 int device_add(struct device *dev)
1608 {
1609 struct device *parent = NULL;
1610 struct kobject *kobj;
1611 struct class_interface *class_intf;
1612 int error = -EINVAL;
1613 struct kobject *glue_dir = NULL;
1614
1615 dev = get_device(dev);
1616 if (!dev)
1617 goto done;
1618
1619 if (!dev->p) {
1620 error = device_private_init(dev);
1621 if (error)
1622 goto done;
1623 }
1624
1625 /*
1626 * for statically allocated devices, which should all be converted
1627 * some day, we need to initialize the name. We prevent reading back
1628 * the name, and force the use of dev_name()
1629 */
1630 if (dev->init_name) {
1631 dev_set_name(dev, "%s", dev->init_name);
1632 dev->init_name = NULL;
1633 }
1634
1635 /* subsystems can specify simple device enumeration */
1636 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
1637 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
1638
1639 if (!dev_name(dev)) {
1640 error = -EINVAL;
1641 goto name_error;
1642 }
1643
1644 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1645
1646 parent = get_device(dev->parent);
1647 kobj = get_device_parent(dev, parent);
1648 if (kobj)
1649 dev->kobj.parent = kobj;
1650
1651 /* use parent numa_node */
1652 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
1653 set_dev_node(dev, dev_to_node(parent));
1654
1655 /* first, register with generic layer. */
1656 /* we require the name to be set before, and pass NULL */
1657 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
1658 if (error) {
1659 glue_dir = get_glue_dir(dev);
1660 goto Error;
1661 }
1662
1663 /* notify platform of device entry */
1664 if (platform_notify)
1665 platform_notify(dev);
1666
1667 error = device_create_file(dev, &dev_attr_uevent);
1668 if (error)
1669 goto attrError;
1670
1671 error = device_add_class_symlinks(dev);
1672 if (error)
1673 goto SymlinkError;
1674 error = device_add_attrs(dev);
1675 if (error)
1676 goto AttrsError;
1677 error = bus_add_device(dev);
1678 if (error)
1679 goto BusError;
1680 error = dpm_sysfs_add(dev);
1681 if (error)
1682 goto DPMError;
1683 device_pm_add(dev);
1684
1685 if (MAJOR(dev->devt)) {
1686 error = device_create_file(dev, &dev_attr_dev);
1687 if (error)
1688 goto DevAttrError;
1689
1690 error = device_create_sys_dev_entry(dev);
1691 if (error)
1692 goto SysEntryError;
1693
1694 devtmpfs_create_node(dev);
1695 }
1696
1697 /* Notify clients of device addition. This call must come
1698 * after dpm_sysfs_add() and before kobject_uevent().
1699 */
1700 if (dev->bus)
1701 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1702 BUS_NOTIFY_ADD_DEVICE, dev);
1703
1704 kobject_uevent(&dev->kobj, KOBJ_ADD);
1705 bus_probe_device(dev);
1706 if (parent)
1707 klist_add_tail(&dev->p->knode_parent,
1708 &parent->p->klist_children);
1709
1710 if (dev->class) {
1711 mutex_lock(&dev->class->p->mutex);
1712 /* tie the class to the device */
1713 klist_add_tail(&dev->knode_class,
1714 &dev->class->p->klist_devices);
1715
1716 /* notify any interfaces that the device is here */
1717 list_for_each_entry(class_intf,
1718 &dev->class->p->interfaces, node)
1719 if (class_intf->add_dev)
1720 class_intf->add_dev(dev, class_intf);
1721 mutex_unlock(&dev->class->p->mutex);
1722 }
1723 done:
1724 put_device(dev);
1725 return error;
1726 SysEntryError:
1727 if (MAJOR(dev->devt))
1728 device_remove_file(dev, &dev_attr_dev);
1729 DevAttrError:
1730 device_pm_remove(dev);
1731 dpm_sysfs_remove(dev);
1732 DPMError:
1733 bus_remove_device(dev);
1734 BusError:
1735 device_remove_attrs(dev);
1736 AttrsError:
1737 device_remove_class_symlinks(dev);
1738 SymlinkError:
1739 device_remove_file(dev, &dev_attr_uevent);
1740 attrError:
1741 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1742 glue_dir = get_glue_dir(dev);
1743 kobject_del(&dev->kobj);
1744 Error:
1745 cleanup_glue_dir(dev, glue_dir);
1746 put_device(parent);
1747 name_error:
1748 kfree(dev->p);
1749 dev->p = NULL;
1750 goto done;
1751 }
1752 EXPORT_SYMBOL_GPL(device_add);
1753
1754 /**
1755 * device_register - register a device with the system.
1756 * @dev: pointer to the device structure
1757 *
1758 * This happens in two clean steps - initialize the device
1759 * and add it to the system. The two steps can be called
1760 * separately, but this is the easiest and most common.
1761 * I.e. you should only call the two helpers separately if
1762 * have a clearly defined need to use and refcount the device
1763 * before it is added to the hierarchy.
1764 *
1765 * For more information, see the kerneldoc for device_initialize()
1766 * and device_add().
1767 *
1768 * NOTE: _Never_ directly free @dev after calling this function, even
1769 * if it returned an error! Always use put_device() to give up the
1770 * reference initialized in this function instead.
1771 */
1772 int device_register(struct device *dev)
1773 {
1774 device_initialize(dev);
1775 return device_add(dev);
1776 }
1777 EXPORT_SYMBOL_GPL(device_register);
1778
1779 /**
1780 * get_device - increment reference count for device.
1781 * @dev: device.
1782 *
1783 * This simply forwards the call to kobject_get(), though
1784 * we do take care to provide for the case that we get a NULL
1785 * pointer passed in.
1786 */
1787 struct device *get_device(struct device *dev)
1788 {
1789 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
1790 }
1791 EXPORT_SYMBOL_GPL(get_device);
1792
1793 /**
1794 * put_device - decrement reference count.
1795 * @dev: device in question.
1796 */
1797 void put_device(struct device *dev)
1798 {
1799 /* might_sleep(); */
1800 if (dev)
1801 kobject_put(&dev->kobj);
1802 }
1803 EXPORT_SYMBOL_GPL(put_device);
1804
1805 /**
1806 * device_del - delete device from system.
1807 * @dev: device.
1808 *
1809 * This is the first part of the device unregistration
1810 * sequence. This removes the device from the lists we control
1811 * from here, has it removed from the other driver model
1812 * subsystems it was added to in device_add(), and removes it
1813 * from the kobject hierarchy.
1814 *
1815 * NOTE: this should be called manually _iff_ device_add() was
1816 * also called manually.
1817 */
1818 void device_del(struct device *dev)
1819 {
1820 struct device *parent = dev->parent;
1821 struct kobject *glue_dir = NULL;
1822 struct class_interface *class_intf;
1823
1824 /* Notify clients of device removal. This call must come
1825 * before dpm_sysfs_remove().
1826 */
1827 if (dev->bus)
1828 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1829 BUS_NOTIFY_DEL_DEVICE, dev);
1830
1831 device_links_purge(dev);
1832 dpm_sysfs_remove(dev);
1833 if (parent)
1834 klist_del(&dev->p->knode_parent);
1835 if (MAJOR(dev->devt)) {
1836 devtmpfs_delete_node(dev);
1837 device_remove_sys_dev_entry(dev);
1838 device_remove_file(dev, &dev_attr_dev);
1839 }
1840 if (dev->class) {
1841 device_remove_class_symlinks(dev);
1842
1843 mutex_lock(&dev->class->p->mutex);
1844 /* notify any interfaces that the device is now gone */
1845 list_for_each_entry(class_intf,
1846 &dev->class->p->interfaces, node)
1847 if (class_intf->remove_dev)
1848 class_intf->remove_dev(dev, class_intf);
1849 /* remove the device from the class list */
1850 klist_del(&dev->knode_class);
1851 mutex_unlock(&dev->class->p->mutex);
1852 }
1853 device_remove_file(dev, &dev_attr_uevent);
1854 device_remove_attrs(dev);
1855 bus_remove_device(dev);
1856 device_pm_remove(dev);
1857 driver_deferred_probe_del(dev);
1858 device_remove_properties(dev);
1859
1860 /* Notify the platform of the removal, in case they
1861 * need to do anything...
1862 */
1863 if (platform_notify_remove)
1864 platform_notify_remove(dev);
1865 if (dev->bus)
1866 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
1867 BUS_NOTIFY_REMOVED_DEVICE, dev);
1868 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
1869 glue_dir = get_glue_dir(dev);
1870 kobject_del(&dev->kobj);
1871 cleanup_glue_dir(dev, glue_dir);
1872 put_device(parent);
1873 }
1874 EXPORT_SYMBOL_GPL(device_del);
1875
1876 /**
1877 * device_unregister - unregister device from system.
1878 * @dev: device going away.
1879 *
1880 * We do this in two parts, like we do device_register(). First,
1881 * we remove it from all the subsystems with device_del(), then
1882 * we decrement the reference count via put_device(). If that
1883 * is the final reference count, the device will be cleaned up
1884 * via device_release() above. Otherwise, the structure will
1885 * stick around until the final reference to the device is dropped.
1886 */
1887 void device_unregister(struct device *dev)
1888 {
1889 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
1890 device_del(dev);
1891 put_device(dev);
1892 }
1893 EXPORT_SYMBOL_GPL(device_unregister);
1894
1895 static struct device *prev_device(struct klist_iter *i)
1896 {
1897 struct klist_node *n = klist_prev(i);
1898 struct device *dev = NULL;
1899 struct device_private *p;
1900
1901 if (n) {
1902 p = to_device_private_parent(n);
1903 dev = p->device;
1904 }
1905 return dev;
1906 }
1907
1908 static struct device *next_device(struct klist_iter *i)
1909 {
1910 struct klist_node *n = klist_next(i);
1911 struct device *dev = NULL;
1912 struct device_private *p;
1913
1914 if (n) {
1915 p = to_device_private_parent(n);
1916 dev = p->device;
1917 }
1918 return dev;
1919 }
1920
1921 /**
1922 * device_get_devnode - path of device node file
1923 * @dev: device
1924 * @mode: returned file access mode
1925 * @uid: returned file owner
1926 * @gid: returned file group
1927 * @tmp: possibly allocated string
1928 *
1929 * Return the relative path of a possible device node.
1930 * Non-default names may need to allocate a memory to compose
1931 * a name. This memory is returned in tmp and needs to be
1932 * freed by the caller.
1933 */
1934 const char *device_get_devnode(struct device *dev,
1935 umode_t *mode, kuid_t *uid, kgid_t *gid,
1936 const char **tmp)
1937 {
1938 char *s;
1939
1940 *tmp = NULL;
1941
1942 /* the device type may provide a specific name */
1943 if (dev->type && dev->type->devnode)
1944 *tmp = dev->type->devnode(dev, mode, uid, gid);
1945 if (*tmp)
1946 return *tmp;
1947
1948 /* the class may provide a specific name */
1949 if (dev->class && dev->class->devnode)
1950 *tmp = dev->class->devnode(dev, mode);
1951 if (*tmp)
1952 return *tmp;
1953
1954 /* return name without allocation, tmp == NULL */
1955 if (strchr(dev_name(dev), '!') == NULL)
1956 return dev_name(dev);
1957
1958 /* replace '!' in the name with '/' */
1959 s = kstrdup(dev_name(dev), GFP_KERNEL);
1960 if (!s)
1961 return NULL;
1962 strreplace(s, '!', '/');
1963 return *tmp = s;
1964 }
1965
1966 /**
1967 * device_for_each_child - device child iterator.
1968 * @parent: parent struct device.
1969 * @fn: function to be called for each device.
1970 * @data: data for the callback.
1971 *
1972 * Iterate over @parent's child devices, and call @fn for each,
1973 * passing it @data.
1974 *
1975 * We check the return of @fn each time. If it returns anything
1976 * other than 0, we break out and return that value.
1977 */
1978 int device_for_each_child(struct device *parent, void *data,
1979 int (*fn)(struct device *dev, void *data))
1980 {
1981 struct klist_iter i;
1982 struct device *child;
1983 int error = 0;
1984
1985 if (!parent->p)
1986 return 0;
1987
1988 klist_iter_init(&parent->p->klist_children, &i);
1989 while ((child = next_device(&i)) && !error)
1990 error = fn(child, data);
1991 klist_iter_exit(&i);
1992 return error;
1993 }
1994 EXPORT_SYMBOL_GPL(device_for_each_child);
1995
1996 /**
1997 * device_for_each_child_reverse - device child iterator in reversed order.
1998 * @parent: parent struct device.
1999 * @fn: function to be called for each device.
2000 * @data: data for the callback.
2001 *
2002 * Iterate over @parent's child devices, and call @fn for each,
2003 * passing it @data.
2004 *
2005 * We check the return of @fn each time. If it returns anything
2006 * other than 0, we break out and return that value.
2007 */
2008 int device_for_each_child_reverse(struct device *parent, void *data,
2009 int (*fn)(struct device *dev, void *data))
2010 {
2011 struct klist_iter i;
2012 struct device *child;
2013 int error = 0;
2014
2015 if (!parent->p)
2016 return 0;
2017
2018 klist_iter_init(&parent->p->klist_children, &i);
2019 while ((child = prev_device(&i)) && !error)
2020 error = fn(child, data);
2021 klist_iter_exit(&i);
2022 return error;
2023 }
2024 EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
2025
2026 /**
2027 * device_find_child - device iterator for locating a particular device.
2028 * @parent: parent struct device
2029 * @match: Callback function to check device
2030 * @data: Data to pass to match function
2031 *
2032 * This is similar to the device_for_each_child() function above, but it
2033 * returns a reference to a device that is 'found' for later use, as
2034 * determined by the @match callback.
2035 *
2036 * The callback should return 0 if the device doesn't match and non-zero
2037 * if it does. If the callback returns non-zero and a reference to the
2038 * current device can be obtained, this function will return to the caller
2039 * and not iterate over any more devices.
2040 *
2041 * NOTE: you will need to drop the reference with put_device() after use.
2042 */
2043 struct device *device_find_child(struct device *parent, void *data,
2044 int (*match)(struct device *dev, void *data))
2045 {
2046 struct klist_iter i;
2047 struct device *child;
2048
2049 if (!parent)
2050 return NULL;
2051
2052 klist_iter_init(&parent->p->klist_children, &i);
2053 while ((child = next_device(&i)))
2054 if (match(child, data) && get_device(child))
2055 break;
2056 klist_iter_exit(&i);
2057 return child;
2058 }
2059 EXPORT_SYMBOL_GPL(device_find_child);
2060
2061 int __init devices_init(void)
2062 {
2063 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
2064 if (!devices_kset)
2065 return -ENOMEM;
2066 dev_kobj = kobject_create_and_add("dev", NULL);
2067 if (!dev_kobj)
2068 goto dev_kobj_err;
2069 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
2070 if (!sysfs_dev_block_kobj)
2071 goto block_kobj_err;
2072 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
2073 if (!sysfs_dev_char_kobj)
2074 goto char_kobj_err;
2075
2076 return 0;
2077
2078 char_kobj_err:
2079 kobject_put(sysfs_dev_block_kobj);
2080 block_kobj_err:
2081 kobject_put(dev_kobj);
2082 dev_kobj_err:
2083 kset_unregister(devices_kset);
2084 return -ENOMEM;
2085 }
2086
2087 static int device_check_offline(struct device *dev, void *not_used)
2088 {
2089 int ret;
2090
2091 ret = device_for_each_child(dev, NULL, device_check_offline);
2092 if (ret)
2093 return ret;
2094
2095 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
2096 }
2097
2098 /**
2099 * device_offline - Prepare the device for hot-removal.
2100 * @dev: Device to be put offline.
2101 *
2102 * Execute the device bus type's .offline() callback, if present, to prepare
2103 * the device for a subsequent hot-removal. If that succeeds, the device must
2104 * not be used until either it is removed or its bus type's .online() callback
2105 * is executed.
2106 *
2107 * Call under device_hotplug_lock.
2108 */
2109 int device_offline(struct device *dev)
2110 {
2111 int ret;
2112
2113 if (dev->offline_disabled)
2114 return -EPERM;
2115
2116 ret = device_for_each_child(dev, NULL, device_check_offline);
2117 if (ret)
2118 return ret;
2119
2120 device_lock(dev);
2121 if (device_supports_offline(dev)) {
2122 if (dev->offline) {
2123 ret = 1;
2124 } else {
2125 ret = dev->bus->offline(dev);
2126 if (!ret) {
2127 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
2128 dev->offline = true;
2129 }
2130 }
2131 }
2132 device_unlock(dev);
2133
2134 return ret;
2135 }
2136
2137 /**
2138 * device_online - Put the device back online after successful device_offline().
2139 * @dev: Device to be put back online.
2140 *
2141 * If device_offline() has been successfully executed for @dev, but the device
2142 * has not been removed subsequently, execute its bus type's .online() callback
2143 * to indicate that the device can be used again.
2144 *
2145 * Call under device_hotplug_lock.
2146 */
2147 int device_online(struct device *dev)
2148 {
2149 int ret = 0;
2150
2151 device_lock(dev);
2152 if (device_supports_offline(dev)) {
2153 if (dev->offline) {
2154 ret = dev->bus->online(dev);
2155 if (!ret) {
2156 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
2157 dev->offline = false;
2158 }
2159 } else {
2160 ret = 1;
2161 }
2162 }
2163 device_unlock(dev);
2164
2165 return ret;
2166 }
2167
2168 struct root_device {
2169 struct device dev;
2170 struct module *owner;
2171 };
2172
2173 static inline struct root_device *to_root_device(struct device *d)
2174 {
2175 return container_of(d, struct root_device, dev);
2176 }
2177
2178 static void root_device_release(struct device *dev)
2179 {
2180 kfree(to_root_device(dev));
2181 }
2182
2183 /**
2184 * __root_device_register - allocate and register a root device
2185 * @name: root device name
2186 * @owner: owner module of the root device, usually THIS_MODULE
2187 *
2188 * This function allocates a root device and registers it
2189 * using device_register(). In order to free the returned
2190 * device, use root_device_unregister().
2191 *
2192 * Root devices are dummy devices which allow other devices
2193 * to be grouped under /sys/devices. Use this function to
2194 * allocate a root device and then use it as the parent of
2195 * any device which should appear under /sys/devices/{name}
2196 *
2197 * The /sys/devices/{name} directory will also contain a
2198 * 'module' symlink which points to the @owner directory
2199 * in sysfs.
2200 *
2201 * Returns &struct device pointer on success, or ERR_PTR() on error.
2202 *
2203 * Note: You probably want to use root_device_register().
2204 */
2205 struct device *__root_device_register(const char *name, struct module *owner)
2206 {
2207 struct root_device *root;
2208 int err = -ENOMEM;
2209
2210 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
2211 if (!root)
2212 return ERR_PTR(err);
2213
2214 err = dev_set_name(&root->dev, "%s", name);
2215 if (err) {
2216 kfree(root);
2217 return ERR_PTR(err);
2218 }
2219
2220 root->dev.release = root_device_release;
2221
2222 err = device_register(&root->dev);
2223 if (err) {
2224 put_device(&root->dev);
2225 return ERR_PTR(err);
2226 }
2227
2228 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2229 if (owner) {
2230 struct module_kobject *mk = &owner->mkobj;
2231
2232 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
2233 if (err) {
2234 device_unregister(&root->dev);
2235 return ERR_PTR(err);
2236 }
2237 root->owner = owner;
2238 }
2239 #endif
2240
2241 return &root->dev;
2242 }
2243 EXPORT_SYMBOL_GPL(__root_device_register);
2244
2245 /**
2246 * root_device_unregister - unregister and free a root device
2247 * @dev: device going away
2248 *
2249 * This function unregisters and cleans up a device that was created by
2250 * root_device_register().
2251 */
2252 void root_device_unregister(struct device *dev)
2253 {
2254 struct root_device *root = to_root_device(dev);
2255
2256 if (root->owner)
2257 sysfs_remove_link(&root->dev.kobj, "module");
2258
2259 device_unregister(dev);
2260 }
2261 EXPORT_SYMBOL_GPL(root_device_unregister);
2262
2263
2264 static void device_create_release(struct device *dev)
2265 {
2266 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
2267 kfree(dev);
2268 }
2269
2270 static struct device *
2271 device_create_groups_vargs(struct class *class, struct device *parent,
2272 dev_t devt, void *drvdata,
2273 const struct attribute_group **groups,
2274 const char *fmt, va_list args)
2275 {
2276 struct device *dev = NULL;
2277 int retval = -ENODEV;
2278
2279 if (class == NULL || IS_ERR(class))
2280 goto error;
2281
2282 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
2283 if (!dev) {
2284 retval = -ENOMEM;
2285 goto error;
2286 }
2287
2288 device_initialize(dev);
2289 dev->devt = devt;
2290 dev->class = class;
2291 dev->parent = parent;
2292 dev->groups = groups;
2293 dev->release = device_create_release;
2294 dev_set_drvdata(dev, drvdata);
2295
2296 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
2297 if (retval)
2298 goto error;
2299
2300 retval = device_add(dev);
2301 if (retval)
2302 goto error;
2303
2304 return dev;
2305
2306 error:
2307 put_device(dev);
2308 return ERR_PTR(retval);
2309 }
2310
2311 /**
2312 * device_create_vargs - creates a device and registers it with sysfs
2313 * @class: pointer to the struct class that this device should be registered to
2314 * @parent: pointer to the parent struct device of this new device, if any
2315 * @devt: the dev_t for the char device to be added
2316 * @drvdata: the data to be added to the device for callbacks
2317 * @fmt: string for the device's name
2318 * @args: va_list for the device's name
2319 *
2320 * This function can be used by char device classes. A struct device
2321 * will be created in sysfs, registered to the specified class.
2322 *
2323 * A "dev" file will be created, showing the dev_t for the device, if
2324 * the dev_t is not 0,0.
2325 * If a pointer to a parent struct device is passed in, the newly created
2326 * struct device will be a child of that device in sysfs.
2327 * The pointer to the struct device will be returned from the call.
2328 * Any further sysfs files that might be required can be created using this
2329 * pointer.
2330 *
2331 * Returns &struct device pointer on success, or ERR_PTR() on error.
2332 *
2333 * Note: the struct class passed to this function must have previously
2334 * been created with a call to class_create().
2335 */
2336 struct device *device_create_vargs(struct class *class, struct device *parent,
2337 dev_t devt, void *drvdata, const char *fmt,
2338 va_list args)
2339 {
2340 return device_create_groups_vargs(class, parent, devt, drvdata, NULL,
2341 fmt, args);
2342 }
2343 EXPORT_SYMBOL_GPL(device_create_vargs);
2344
2345 /**
2346 * device_create - creates a device and registers it with sysfs
2347 * @class: pointer to the struct class that this device should be registered to
2348 * @parent: pointer to the parent struct device of this new device, if any
2349 * @devt: the dev_t for the char device to be added
2350 * @drvdata: the data to be added to the device for callbacks
2351 * @fmt: string for the device's name
2352 *
2353 * This function can be used by char device classes. A struct device
2354 * will be created in sysfs, registered to the specified class.
2355 *
2356 * A "dev" file will be created, showing the dev_t for the device, if
2357 * the dev_t is not 0,0.
2358 * If a pointer to a parent struct device is passed in, the newly created
2359 * struct device will be a child of that device in sysfs.
2360 * The pointer to the struct device will be returned from the call.
2361 * Any further sysfs files that might be required can be created using this
2362 * pointer.
2363 *
2364 * Returns &struct device pointer on success, or ERR_PTR() on error.
2365 *
2366 * Note: the struct class passed to this function must have previously
2367 * been created with a call to class_create().
2368 */
2369 struct device *device_create(struct class *class, struct device *parent,
2370 dev_t devt, void *drvdata, const char *fmt, ...)
2371 {
2372 va_list vargs;
2373 struct device *dev;
2374
2375 va_start(vargs, fmt);
2376 dev = device_create_vargs(class, parent, devt, drvdata, fmt, vargs);
2377 va_end(vargs);
2378 return dev;
2379 }
2380 EXPORT_SYMBOL_GPL(device_create);
2381
2382 /**
2383 * device_create_with_groups - creates a device and registers it with sysfs
2384 * @class: pointer to the struct class that this device should be registered to
2385 * @parent: pointer to the parent struct device of this new device, if any
2386 * @devt: the dev_t for the char device to be added
2387 * @drvdata: the data to be added to the device for callbacks
2388 * @groups: NULL-terminated list of attribute groups to be created
2389 * @fmt: string for the device's name
2390 *
2391 * This function can be used by char device classes. A struct device
2392 * will be created in sysfs, registered to the specified class.
2393 * Additional attributes specified in the groups parameter will also
2394 * be created automatically.
2395 *
2396 * A "dev" file will be created, showing the dev_t for the device, if
2397 * the dev_t is not 0,0.
2398 * If a pointer to a parent struct device is passed in, the newly created
2399 * struct device will be a child of that device in sysfs.
2400 * The pointer to the struct device will be returned from the call.
2401 * Any further sysfs files that might be required can be created using this
2402 * pointer.
2403 *
2404 * Returns &struct device pointer on success, or ERR_PTR() on error.
2405 *
2406 * Note: the struct class passed to this function must have previously
2407 * been created with a call to class_create().
2408 */
2409 struct device *device_create_with_groups(struct class *class,
2410 struct device *parent, dev_t devt,
2411 void *drvdata,
2412 const struct attribute_group **groups,
2413 const char *fmt, ...)
2414 {
2415 va_list vargs;
2416 struct device *dev;
2417
2418 va_start(vargs, fmt);
2419 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
2420 fmt, vargs);
2421 va_end(vargs);
2422 return dev;
2423 }
2424 EXPORT_SYMBOL_GPL(device_create_with_groups);
2425
2426 static int __match_devt(struct device *dev, const void *data)
2427 {
2428 const dev_t *devt = data;
2429
2430 return dev->devt == *devt;
2431 }
2432
2433 /**
2434 * device_destroy - removes a device that was created with device_create()
2435 * @class: pointer to the struct class that this device was registered with
2436 * @devt: the dev_t of the device that was previously registered
2437 *
2438 * This call unregisters and cleans up a device that was created with a
2439 * call to device_create().
2440 */
2441 void device_destroy(struct class *class, dev_t devt)
2442 {
2443 struct device *dev;
2444
2445 dev = class_find_device(class, NULL, &devt, __match_devt);
2446 if (dev) {
2447 put_device(dev);
2448 device_unregister(dev);
2449 }
2450 }
2451 EXPORT_SYMBOL_GPL(device_destroy);
2452
2453 /**
2454 * device_rename - renames a device
2455 * @dev: the pointer to the struct device to be renamed
2456 * @new_name: the new name of the device
2457 *
2458 * It is the responsibility of the caller to provide mutual
2459 * exclusion between two different calls of device_rename
2460 * on the same device to ensure that new_name is valid and
2461 * won't conflict with other devices.
2462 *
2463 * Note: Don't call this function. Currently, the networking layer calls this
2464 * function, but that will change. The following text from Kay Sievers offers
2465 * some insight:
2466 *
2467 * Renaming devices is racy at many levels, symlinks and other stuff are not
2468 * replaced atomically, and you get a "move" uevent, but it's not easy to
2469 * connect the event to the old and new device. Device nodes are not renamed at
2470 * all, there isn't even support for that in the kernel now.
2471 *
2472 * In the meantime, during renaming, your target name might be taken by another
2473 * driver, creating conflicts. Or the old name is taken directly after you
2474 * renamed it -- then you get events for the same DEVPATH, before you even see
2475 * the "move" event. It's just a mess, and nothing new should ever rely on
2476 * kernel device renaming. Besides that, it's not even implemented now for
2477 * other things than (driver-core wise very simple) network devices.
2478 *
2479 * We are currently about to change network renaming in udev to completely
2480 * disallow renaming of devices in the same namespace as the kernel uses,
2481 * because we can't solve the problems properly, that arise with swapping names
2482 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2483 * be allowed to some other name than eth[0-9]*, for the aforementioned
2484 * reasons.
2485 *
2486 * Make up a "real" name in the driver before you register anything, or add
2487 * some other attributes for userspace to find the device, or use udev to add
2488 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2489 * don't even want to get into that and try to implement the missing pieces in
2490 * the core. We really have other pieces to fix in the driver core mess. :)
2491 */
2492 int device_rename(struct device *dev, const char *new_name)
2493 {
2494 struct kobject *kobj = &dev->kobj;
2495 char *old_device_name = NULL;
2496 int error;
2497
2498 dev = get_device(dev);
2499 if (!dev)
2500 return -EINVAL;
2501
2502 dev_dbg(dev, "renaming to %s\n", new_name);
2503
2504 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
2505 if (!old_device_name) {
2506 error = -ENOMEM;
2507 goto out;
2508 }
2509
2510 if (dev->class) {
2511 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
2512 kobj, old_device_name,
2513 new_name, kobject_namespace(kobj));
2514 if (error)
2515 goto out;
2516 }
2517
2518 error = kobject_rename(kobj, new_name);
2519 if (error)
2520 goto out;
2521
2522 out:
2523 put_device(dev);
2524
2525 kfree(old_device_name);
2526
2527 return error;
2528 }
2529 EXPORT_SYMBOL_GPL(device_rename);
2530
2531 static int device_move_class_links(struct device *dev,
2532 struct device *old_parent,
2533 struct device *new_parent)
2534 {
2535 int error = 0;
2536
2537 if (old_parent)
2538 sysfs_remove_link(&dev->kobj, "device");
2539 if (new_parent)
2540 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
2541 "device");
2542 return error;
2543 }
2544
2545 /**
2546 * device_move - moves a device to a new parent
2547 * @dev: the pointer to the struct device to be moved
2548 * @new_parent: the new parent of the device (can by NULL)
2549 * @dpm_order: how to reorder the dpm_list
2550 */
2551 int device_move(struct device *dev, struct device *new_parent,
2552 enum dpm_order dpm_order)
2553 {
2554 int error;
2555 struct device *old_parent;
2556 struct kobject *new_parent_kobj;
2557
2558 dev = get_device(dev);
2559 if (!dev)
2560 return -EINVAL;
2561
2562 device_pm_lock();
2563 new_parent = get_device(new_parent);
2564 new_parent_kobj = get_device_parent(dev, new_parent);
2565
2566 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
2567 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
2568 error = kobject_move(&dev->kobj, new_parent_kobj);
2569 if (error) {
2570 cleanup_glue_dir(dev, new_parent_kobj);
2571 put_device(new_parent);
2572 goto out;
2573 }
2574 old_parent = dev->parent;
2575 dev->parent = new_parent;
2576 if (old_parent)
2577 klist_remove(&dev->p->knode_parent);
2578 if (new_parent) {
2579 klist_add_tail(&dev->p->knode_parent,
2580 &new_parent->p->klist_children);
2581 set_dev_node(dev, dev_to_node(new_parent));
2582 }
2583
2584 if (dev->class) {
2585 error = device_move_class_links(dev, old_parent, new_parent);
2586 if (error) {
2587 /* We ignore errors on cleanup since we're hosed anyway... */
2588 device_move_class_links(dev, new_parent, old_parent);
2589 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
2590 if (new_parent)
2591 klist_remove(&dev->p->knode_parent);
2592 dev->parent = old_parent;
2593 if (old_parent) {
2594 klist_add_tail(&dev->p->knode_parent,
2595 &old_parent->p->klist_children);
2596 set_dev_node(dev, dev_to_node(old_parent));
2597 }
2598 }
2599 cleanup_glue_dir(dev, new_parent_kobj);
2600 put_device(new_parent);
2601 goto out;
2602 }
2603 }
2604 switch (dpm_order) {
2605 case DPM_ORDER_NONE:
2606 break;
2607 case DPM_ORDER_DEV_AFTER_PARENT:
2608 device_pm_move_after(dev, new_parent);
2609 devices_kset_move_after(dev, new_parent);
2610 break;
2611 case DPM_ORDER_PARENT_BEFORE_DEV:
2612 device_pm_move_before(new_parent, dev);
2613 devices_kset_move_before(new_parent, dev);
2614 break;
2615 case DPM_ORDER_DEV_LAST:
2616 device_pm_move_last(dev);
2617 devices_kset_move_last(dev);
2618 break;
2619 }
2620
2621 put_device(old_parent);
2622 out:
2623 device_pm_unlock();
2624 put_device(dev);
2625 return error;
2626 }
2627 EXPORT_SYMBOL_GPL(device_move);
2628
2629 /**
2630 * device_shutdown - call ->shutdown() on each device to shutdown.
2631 */
2632 void device_shutdown(void)
2633 {
2634 struct device *dev, *parent;
2635
2636 spin_lock(&devices_kset->list_lock);
2637 /*
2638 * Walk the devices list backward, shutting down each in turn.
2639 * Beware that device unplug events may also start pulling
2640 * devices offline, even as the system is shutting down.
2641 */
2642 while (!list_empty(&devices_kset->list)) {
2643 dev = list_entry(devices_kset->list.prev, struct device,
2644 kobj.entry);
2645
2646 /*
2647 * hold reference count of device's parent to
2648 * prevent it from being freed because parent's
2649 * lock is to be held
2650 */
2651 parent = get_device(dev->parent);
2652 get_device(dev);
2653 /*
2654 * Make sure the device is off the kset list, in the
2655 * event that dev->*->shutdown() doesn't remove it.
2656 */
2657 list_del_init(&dev->kobj.entry);
2658 spin_unlock(&devices_kset->list_lock);
2659
2660 /* hold lock to avoid race with probe/release */
2661 if (parent)
2662 device_lock(parent);
2663 device_lock(dev);
2664
2665 /* Don't allow any more runtime suspends */
2666 pm_runtime_get_noresume(dev);
2667 pm_runtime_barrier(dev);
2668
2669 if (dev->bus && dev->bus->shutdown) {
2670 if (initcall_debug)
2671 dev_info(dev, "shutdown\n");
2672 dev->bus->shutdown(dev);
2673 } else if (dev->driver && dev->driver->shutdown) {
2674 if (initcall_debug)
2675 dev_info(dev, "shutdown\n");
2676 dev->driver->shutdown(dev);
2677 }
2678
2679 device_unlock(dev);
2680 if (parent)
2681 device_unlock(parent);
2682
2683 put_device(dev);
2684 put_device(parent);
2685
2686 spin_lock(&devices_kset->list_lock);
2687 }
2688 spin_unlock(&devices_kset->list_lock);
2689 }
2690
2691 /*
2692 * Device logging functions
2693 */
2694
2695 #ifdef CONFIG_PRINTK
2696 static int
2697 create_syslog_header(const struct device *dev, char *hdr, size_t hdrlen)
2698 {
2699 const char *subsys;
2700 size_t pos = 0;
2701
2702 if (dev->class)
2703 subsys = dev->class->name;
2704 else if (dev->bus)
2705 subsys = dev->bus->name;
2706 else
2707 return 0;
2708
2709 pos += snprintf(hdr + pos, hdrlen - pos, "SUBSYSTEM=%s", subsys);
2710 if (pos >= hdrlen)
2711 goto overflow;
2712
2713 /*
2714 * Add device identifier DEVICE=:
2715 * b12:8 block dev_t
2716 * c127:3 char dev_t
2717 * n8 netdev ifindex
2718 * +sound:card0 subsystem:devname
2719 */
2720 if (MAJOR(dev->devt)) {
2721 char c;
2722
2723 if (strcmp(subsys, "block") == 0)
2724 c = 'b';
2725 else
2726 c = 'c';
2727 pos++;
2728 pos += snprintf(hdr + pos, hdrlen - pos,
2729 "DEVICE=%c%u:%u",
2730 c, MAJOR(dev->devt), MINOR(dev->devt));
2731 } else if (strcmp(subsys, "net") == 0) {
2732 struct net_device *net = to_net_dev(dev);
2733
2734 pos++;
2735 pos += snprintf(hdr + pos, hdrlen - pos,
2736 "DEVICE=n%u", net->ifindex);
2737 } else {
2738 pos++;
2739 pos += snprintf(hdr + pos, hdrlen - pos,
2740 "DEVICE=+%s:%s", subsys, dev_name(dev));
2741 }
2742
2743 if (pos >= hdrlen)
2744 goto overflow;
2745
2746 return pos;
2747
2748 overflow:
2749 dev_WARN(dev, "device/subsystem name too long");
2750 return 0;
2751 }
2752
2753 int dev_vprintk_emit(int level, const struct device *dev,
2754 const char *fmt, va_list args)
2755 {
2756 char hdr[128];
2757 size_t hdrlen;
2758
2759 hdrlen = create_syslog_header(dev, hdr, sizeof(hdr));
2760
2761 return vprintk_emit(0, level, hdrlen ? hdr : NULL, hdrlen, fmt, args);
2762 }
2763 EXPORT_SYMBOL(dev_vprintk_emit);
2764
2765 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
2766 {
2767 va_list args;
2768 int r;
2769
2770 va_start(args, fmt);
2771
2772 r = dev_vprintk_emit(level, dev, fmt, args);
2773
2774 va_end(args);
2775
2776 return r;
2777 }
2778 EXPORT_SYMBOL(dev_printk_emit);
2779
2780 static void __dev_printk(const char *level, const struct device *dev,
2781 struct va_format *vaf)
2782 {
2783 if (dev)
2784 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
2785 dev_driver_string(dev), dev_name(dev), vaf);
2786 else
2787 printk("%s(NULL device *): %pV", level, vaf);
2788 }
2789
2790 void dev_printk(const char *level, const struct device *dev,
2791 const char *fmt, ...)
2792 {
2793 struct va_format vaf;
2794 va_list args;
2795
2796 va_start(args, fmt);
2797
2798 vaf.fmt = fmt;
2799 vaf.va = &args;
2800
2801 __dev_printk(level, dev, &vaf);
2802
2803 va_end(args);
2804 }
2805 EXPORT_SYMBOL(dev_printk);
2806
2807 #define define_dev_printk_level(func, kern_level) \
2808 void func(const struct device *dev, const char *fmt, ...) \
2809 { \
2810 struct va_format vaf; \
2811 va_list args; \
2812 \
2813 va_start(args, fmt); \
2814 \
2815 vaf.fmt = fmt; \
2816 vaf.va = &args; \
2817 \
2818 __dev_printk(kern_level, dev, &vaf); \
2819 \
2820 va_end(args); \
2821 } \
2822 EXPORT_SYMBOL(func);
2823
2824 define_dev_printk_level(dev_emerg, KERN_EMERG);
2825 define_dev_printk_level(dev_alert, KERN_ALERT);
2826 define_dev_printk_level(dev_crit, KERN_CRIT);
2827 define_dev_printk_level(dev_err, KERN_ERR);
2828 define_dev_printk_level(dev_warn, KERN_WARNING);
2829 define_dev_printk_level(dev_notice, KERN_NOTICE);
2830 define_dev_printk_level(_dev_info, KERN_INFO);
2831
2832 #endif
2833
2834 static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
2835 {
2836 return fwnode && !IS_ERR(fwnode->secondary);
2837 }
2838
2839 /**
2840 * set_primary_fwnode - Change the primary firmware node of a given device.
2841 * @dev: Device to handle.
2842 * @fwnode: New primary firmware node of the device.
2843 *
2844 * Set the device's firmware node pointer to @fwnode, but if a secondary
2845 * firmware node of the device is present, preserve it.
2846 */
2847 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2848 {
2849 if (fwnode) {
2850 struct fwnode_handle *fn = dev->fwnode;
2851
2852 if (fwnode_is_primary(fn))
2853 fn = fn->secondary;
2854
2855 if (fn) {
2856 WARN_ON(fwnode->secondary);
2857 fwnode->secondary = fn;
2858 }
2859 dev->fwnode = fwnode;
2860 } else {
2861 dev->fwnode = fwnode_is_primary(dev->fwnode) ?
2862 dev->fwnode->secondary : NULL;
2863 }
2864 }
2865 EXPORT_SYMBOL_GPL(set_primary_fwnode);
2866
2867 /**
2868 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2869 * @dev: Device to handle.
2870 * @fwnode: New secondary firmware node of the device.
2871 *
2872 * If a primary firmware node of the device is present, set its secondary
2873 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2874 * @fwnode.
2875 */
2876 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
2877 {
2878 if (fwnode)
2879 fwnode->secondary = ERR_PTR(-ENODEV);
2880
2881 if (fwnode_is_primary(dev->fwnode))
2882 dev->fwnode->secondary = fwnode;
2883 else
2884 dev->fwnode = fwnode;
2885 }