2 * drivers/base/core.c - core driver model code (device registration, etc)
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.
9 * This file is released under the GPLv2
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>
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/sched/signal.h>
30 #include <linux/sysfs.h>
33 #include "power/power.h"
35 #ifdef CONFIG_SYSFS_DEPRECATED
36 #ifdef CONFIG_SYSFS_DEPRECATED_V2
37 long sysfs_deprecated
= 1;
39 long sysfs_deprecated
= 0;
41 static int __init
sysfs_deprecated_setup(char *arg
)
43 return kstrtol(arg
, 10, &sysfs_deprecated
);
45 early_param("sysfs.deprecated", sysfs_deprecated_setup
);
48 /* Device links support. */
51 static DEFINE_MUTEX(device_links_lock
);
52 DEFINE_STATIC_SRCU(device_links_srcu
);
54 static inline void device_links_write_lock(void)
56 mutex_lock(&device_links_lock
);
59 static inline void device_links_write_unlock(void)
61 mutex_unlock(&device_links_lock
);
64 int device_links_read_lock(void)
66 return srcu_read_lock(&device_links_srcu
);
69 void device_links_read_unlock(int idx
)
71 srcu_read_unlock(&device_links_srcu
, idx
);
73 #else /* !CONFIG_SRCU */
74 static DECLARE_RWSEM(device_links_lock
);
76 static inline void device_links_write_lock(void)
78 down_write(&device_links_lock
);
81 static inline void device_links_write_unlock(void)
83 up_write(&device_links_lock
);
86 int device_links_read_lock(void)
88 down_read(&device_links_lock
);
92 void device_links_read_unlock(int not_used
)
94 up_read(&device_links_lock
);
96 #endif /* !CONFIG_SRCU */
99 * device_is_dependent - Check if one device depends on another one
100 * @dev: Device to check dependencies for.
101 * @target: Device to check against.
103 * Check if @target depends on @dev or any device dependent on it (its child or
104 * its consumer etc). Return 1 if that is the case or 0 otherwise.
106 static int device_is_dependent(struct device
*dev
, void *target
)
108 struct device_link
*link
;
111 if (WARN_ON(dev
== target
))
114 ret
= device_for_each_child(dev
, target
, device_is_dependent
);
118 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
119 if (WARN_ON(link
->consumer
== target
))
122 ret
= device_is_dependent(link
->consumer
, target
);
129 static int device_reorder_to_tail(struct device
*dev
, void *not_used
)
131 struct device_link
*link
;
134 * Devices that have not been registered yet will be put to the ends
135 * of the lists during the registration, so skip them here.
137 if (device_is_registered(dev
))
138 devices_kset_move_last(dev
);
140 if (device_pm_initialized(dev
))
141 device_pm_move_last(dev
);
143 device_for_each_child(dev
, NULL
, device_reorder_to_tail
);
144 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
)
145 device_reorder_to_tail(link
->consumer
, NULL
);
151 * device_link_add - Create a link between two devices.
152 * @consumer: Consumer end of the link.
153 * @supplier: Supplier end of the link.
154 * @flags: Link flags.
156 * The caller is responsible for the proper synchronization of the link creation
157 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
158 * runtime PM framework to take the link into account. Second, if the
159 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
160 * be forced into the active metastate and reference-counted upon the creation
161 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
164 * If the DL_FLAG_AUTOREMOVE is set, the link will be removed automatically
165 * when the consumer device driver unbinds from it. The combination of both
166 * DL_FLAG_AUTOREMOVE and DL_FLAG_STATELESS set is invalid and will cause NULL
169 * A side effect of the link creation is re-ordering of dpm_list and the
170 * devices_kset list by moving the consumer device and all devices depending
171 * on it to the ends of these lists (that does not happen to devices that have
172 * not been registered when this function is called).
174 * The supplier device is required to be registered when this function is called
175 * and NULL will be returned if that is not the case. The consumer device need
176 * not be registered, however.
178 struct device_link
*device_link_add(struct device
*consumer
,
179 struct device
*supplier
, u32 flags
)
181 struct device_link
*link
;
183 if (!consumer
|| !supplier
||
184 ((flags
& DL_FLAG_STATELESS
) && (flags
& DL_FLAG_AUTOREMOVE
)))
187 device_links_write_lock();
191 * If the supplier has not been fully registered yet or there is a
192 * reverse dependency between the consumer and the supplier already in
193 * the graph, return NULL.
195 if (!device_pm_initialized(supplier
)
196 || device_is_dependent(consumer
, supplier
)) {
201 list_for_each_entry(link
, &supplier
->links
.consumers
, s_node
)
202 if (link
->consumer
== consumer
)
205 link
= kzalloc(sizeof(*link
), GFP_KERNEL
);
209 if (flags
& DL_FLAG_PM_RUNTIME
) {
210 if (flags
& DL_FLAG_RPM_ACTIVE
) {
211 if (pm_runtime_get_sync(supplier
) < 0) {
212 pm_runtime_put_noidle(supplier
);
217 link
->rpm_active
= true;
219 pm_runtime_new_link(consumer
);
221 get_device(supplier
);
222 link
->supplier
= supplier
;
223 INIT_LIST_HEAD(&link
->s_node
);
224 get_device(consumer
);
225 link
->consumer
= consumer
;
226 INIT_LIST_HEAD(&link
->c_node
);
229 /* Determine the initial link state. */
230 if (flags
& DL_FLAG_STATELESS
) {
231 link
->status
= DL_STATE_NONE
;
233 switch (supplier
->links
.status
) {
234 case DL_DEV_DRIVER_BOUND
:
235 switch (consumer
->links
.status
) {
238 * Balance the decrementation of the supplier's
239 * runtime PM usage counter after consumer probe
240 * in driver_probe_device().
242 if (flags
& DL_FLAG_PM_RUNTIME
)
243 pm_runtime_get_sync(supplier
);
245 link
->status
= DL_STATE_CONSUMER_PROBE
;
247 case DL_DEV_DRIVER_BOUND
:
248 link
->status
= DL_STATE_ACTIVE
;
251 link
->status
= DL_STATE_AVAILABLE
;
255 case DL_DEV_UNBINDING
:
256 link
->status
= DL_STATE_SUPPLIER_UNBIND
;
259 link
->status
= DL_STATE_DORMANT
;
265 * Move the consumer and all of the devices depending on it to the end
266 * of dpm_list and the devices_kset list.
268 * It is necessary to hold dpm_list locked throughout all that or else
269 * we may end up suspending with a wrong ordering of it.
271 device_reorder_to_tail(consumer
, NULL
);
273 list_add_tail_rcu(&link
->s_node
, &supplier
->links
.consumers
);
274 list_add_tail_rcu(&link
->c_node
, &consumer
->links
.suppliers
);
276 dev_info(consumer
, "Linked as a consumer to %s\n", dev_name(supplier
));
280 device_links_write_unlock();
283 EXPORT_SYMBOL_GPL(device_link_add
);
285 static void device_link_free(struct device_link
*link
)
287 put_device(link
->consumer
);
288 put_device(link
->supplier
);
293 static void __device_link_free_srcu(struct rcu_head
*rhead
)
295 device_link_free(container_of(rhead
, struct device_link
, rcu_head
));
298 static void __device_link_del(struct device_link
*link
)
300 dev_info(link
->consumer
, "Dropping the link to %s\n",
301 dev_name(link
->supplier
));
303 if (link
->flags
& DL_FLAG_PM_RUNTIME
)
304 pm_runtime_drop_link(link
->consumer
);
306 list_del_rcu(&link
->s_node
);
307 list_del_rcu(&link
->c_node
);
308 call_srcu(&device_links_srcu
, &link
->rcu_head
, __device_link_free_srcu
);
310 #else /* !CONFIG_SRCU */
311 static void __device_link_del(struct device_link
*link
)
313 dev_info(link
->consumer
, "Dropping the link to %s\n",
314 dev_name(link
->supplier
));
316 list_del(&link
->s_node
);
317 list_del(&link
->c_node
);
318 device_link_free(link
);
320 #endif /* !CONFIG_SRCU */
323 * device_link_del - Delete a link between two devices.
324 * @link: Device link to delete.
326 * The caller must ensure proper synchronization of this function with runtime
329 void device_link_del(struct device_link
*link
)
331 device_links_write_lock();
333 __device_link_del(link
);
335 device_links_write_unlock();
337 EXPORT_SYMBOL_GPL(device_link_del
);
339 static void device_links_missing_supplier(struct device
*dev
)
341 struct device_link
*link
;
343 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
)
344 if (link
->status
== DL_STATE_CONSUMER_PROBE
)
345 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
349 * device_links_check_suppliers - Check presence of supplier drivers.
350 * @dev: Consumer device.
352 * Check links from this device to any suppliers. Walk the list of the device's
353 * links to suppliers and see if all of them are available. If not, simply
354 * return -EPROBE_DEFER.
356 * We need to guarantee that the supplier will not go away after the check has
357 * been positive here. It only can go away in __device_release_driver() and
358 * that function checks the device's links to consumers. This means we need to
359 * mark the link as "consumer probe in progress" to make the supplier removal
360 * wait for us to complete (or bad things may happen).
362 * Links with the DL_FLAG_STATELESS flag set are ignored.
364 int device_links_check_suppliers(struct device
*dev
)
366 struct device_link
*link
;
369 device_links_write_lock();
371 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
) {
372 if (link
->flags
& DL_FLAG_STATELESS
)
375 if (link
->status
!= DL_STATE_AVAILABLE
) {
376 device_links_missing_supplier(dev
);
380 WRITE_ONCE(link
->status
, DL_STATE_CONSUMER_PROBE
);
382 dev
->links
.status
= DL_DEV_PROBING
;
384 device_links_write_unlock();
389 * device_links_driver_bound - Update device links after probing its driver.
390 * @dev: Device to update the links for.
392 * The probe has been successful, so update links from this device to any
393 * consumers by changing their status to "available".
395 * Also change the status of @dev's links to suppliers to "active".
397 * Links with the DL_FLAG_STATELESS flag set are ignored.
399 void device_links_driver_bound(struct device
*dev
)
401 struct device_link
*link
;
403 device_links_write_lock();
405 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
406 if (link
->flags
& DL_FLAG_STATELESS
)
409 WARN_ON(link
->status
!= DL_STATE_DORMANT
);
410 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
413 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
) {
414 if (link
->flags
& DL_FLAG_STATELESS
)
417 WARN_ON(link
->status
!= DL_STATE_CONSUMER_PROBE
);
418 WRITE_ONCE(link
->status
, DL_STATE_ACTIVE
);
421 dev
->links
.status
= DL_DEV_DRIVER_BOUND
;
423 device_links_write_unlock();
427 * __device_links_no_driver - Update links of a device without a driver.
428 * @dev: Device without a drvier.
430 * Delete all non-persistent links from this device to any suppliers.
432 * Persistent links stay around, but their status is changed to "available",
433 * unless they already are in the "supplier unbind in progress" state in which
434 * case they need not be updated.
436 * Links with the DL_FLAG_STATELESS flag set are ignored.
438 static void __device_links_no_driver(struct device
*dev
)
440 struct device_link
*link
, *ln
;
442 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.suppliers
, c_node
) {
443 if (link
->flags
& DL_FLAG_STATELESS
)
446 if (link
->flags
& DL_FLAG_AUTOREMOVE
)
447 __device_link_del(link
);
448 else if (link
->status
!= DL_STATE_SUPPLIER_UNBIND
)
449 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
452 dev
->links
.status
= DL_DEV_NO_DRIVER
;
455 void device_links_no_driver(struct device
*dev
)
457 device_links_write_lock();
458 __device_links_no_driver(dev
);
459 device_links_write_unlock();
463 * device_links_driver_cleanup - Update links after driver removal.
464 * @dev: Device whose driver has just gone away.
466 * Update links to consumers for @dev by changing their status to "dormant" and
467 * invoke %__device_links_no_driver() to update links to suppliers for it as
470 * Links with the DL_FLAG_STATELESS flag set are ignored.
472 void device_links_driver_cleanup(struct device
*dev
)
474 struct device_link
*link
;
476 device_links_write_lock();
478 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
479 if (link
->flags
& DL_FLAG_STATELESS
)
482 WARN_ON(link
->flags
& DL_FLAG_AUTOREMOVE
);
483 WARN_ON(link
->status
!= DL_STATE_SUPPLIER_UNBIND
);
484 WRITE_ONCE(link
->status
, DL_STATE_DORMANT
);
487 __device_links_no_driver(dev
);
489 device_links_write_unlock();
493 * device_links_busy - Check if there are any busy links to consumers.
494 * @dev: Device to check.
496 * Check each consumer of the device and return 'true' if its link's status
497 * is one of "consumer probe" or "active" (meaning that the given consumer is
498 * probing right now or its driver is present). Otherwise, change the link
499 * state to "supplier unbind" to prevent the consumer from being probed
500 * successfully going forward.
502 * Return 'false' if there are no probing or active consumers.
504 * Links with the DL_FLAG_STATELESS flag set are ignored.
506 bool device_links_busy(struct device
*dev
)
508 struct device_link
*link
;
511 device_links_write_lock();
513 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
514 if (link
->flags
& DL_FLAG_STATELESS
)
517 if (link
->status
== DL_STATE_CONSUMER_PROBE
518 || link
->status
== DL_STATE_ACTIVE
) {
522 WRITE_ONCE(link
->status
, DL_STATE_SUPPLIER_UNBIND
);
525 dev
->links
.status
= DL_DEV_UNBINDING
;
527 device_links_write_unlock();
532 * device_links_unbind_consumers - Force unbind consumers of the given device.
533 * @dev: Device to unbind the consumers of.
535 * Walk the list of links to consumers for @dev and if any of them is in the
536 * "consumer probe" state, wait for all device probes in progress to complete
539 * If that's not the case, change the status of the link to "supplier unbind"
540 * and check if the link was in the "active" state. If so, force the consumer
541 * driver to unbind and start over (the consumer will not re-probe as we have
542 * changed the state of the link already).
544 * Links with the DL_FLAG_STATELESS flag set are ignored.
546 void device_links_unbind_consumers(struct device
*dev
)
548 struct device_link
*link
;
551 device_links_write_lock();
553 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
554 enum device_link_state status
;
556 if (link
->flags
& DL_FLAG_STATELESS
)
559 status
= link
->status
;
560 if (status
== DL_STATE_CONSUMER_PROBE
) {
561 device_links_write_unlock();
563 wait_for_device_probe();
566 WRITE_ONCE(link
->status
, DL_STATE_SUPPLIER_UNBIND
);
567 if (status
== DL_STATE_ACTIVE
) {
568 struct device
*consumer
= link
->consumer
;
570 get_device(consumer
);
572 device_links_write_unlock();
574 device_release_driver_internal(consumer
, NULL
,
576 put_device(consumer
);
581 device_links_write_unlock();
585 * device_links_purge - Delete existing links to other devices.
586 * @dev: Target device.
588 static void device_links_purge(struct device
*dev
)
590 struct device_link
*link
, *ln
;
593 * Delete all of the remaining links from this device to any other
594 * devices (either consumers or suppliers).
596 device_links_write_lock();
598 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.suppliers
, c_node
) {
599 WARN_ON(link
->status
== DL_STATE_ACTIVE
);
600 __device_link_del(link
);
603 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.consumers
, s_node
) {
604 WARN_ON(link
->status
!= DL_STATE_DORMANT
&&
605 link
->status
!= DL_STATE_NONE
);
606 __device_link_del(link
);
609 device_links_write_unlock();
612 /* Device links support end. */
614 int (*platform_notify
)(struct device
*dev
) = NULL
;
615 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
616 static struct kobject
*dev_kobj
;
617 struct kobject
*sysfs_dev_char_kobj
;
618 struct kobject
*sysfs_dev_block_kobj
;
620 static DEFINE_MUTEX(device_hotplug_lock
);
622 void lock_device_hotplug(void)
624 mutex_lock(&device_hotplug_lock
);
627 void unlock_device_hotplug(void)
629 mutex_unlock(&device_hotplug_lock
);
632 int lock_device_hotplug_sysfs(void)
634 if (mutex_trylock(&device_hotplug_lock
))
637 /* Avoid busy looping (5 ms of sleep should do). */
639 return restart_syscall();
643 static inline int device_is_not_partition(struct device
*dev
)
645 return !(dev
->type
== &part_type
);
648 static inline int device_is_not_partition(struct device
*dev
)
655 * dev_driver_string - Return a device's driver name, if at all possible
656 * @dev: struct device to get the name of
658 * Will return the device's driver's name if it is bound to a device. If
659 * the device is not bound to a driver, it will return the name of the bus
660 * it is attached to. If it is not attached to a bus either, an empty
661 * string will be returned.
663 const char *dev_driver_string(const struct device
*dev
)
665 struct device_driver
*drv
;
667 /* dev->driver can change to NULL underneath us because of unbinding,
668 * so be careful about accessing it. dev->bus and dev->class should
669 * never change once they are set, so they don't need special care.
671 drv
= ACCESS_ONCE(dev
->driver
);
672 return drv
? drv
->name
:
673 (dev
->bus
? dev
->bus
->name
:
674 (dev
->class ? dev
->class->name
: ""));
676 EXPORT_SYMBOL(dev_driver_string
);
678 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
680 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
683 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
684 struct device
*dev
= kobj_to_dev(kobj
);
688 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
689 if (ret
>= (ssize_t
)PAGE_SIZE
) {
690 print_symbol("dev_attr_show: %s returned bad count\n",
691 (unsigned long)dev_attr
->show
);
696 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
697 const char *buf
, size_t count
)
699 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
700 struct device
*dev
= kobj_to_dev(kobj
);
704 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
708 static const struct sysfs_ops dev_sysfs_ops
= {
709 .show
= dev_attr_show
,
710 .store
= dev_attr_store
,
713 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
715 ssize_t
device_store_ulong(struct device
*dev
,
716 struct device_attribute
*attr
,
717 const char *buf
, size_t size
)
719 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
721 unsigned long new = simple_strtoul(buf
, &end
, 0);
724 *(unsigned long *)(ea
->var
) = new;
725 /* Always return full write size even if we didn't consume all */
728 EXPORT_SYMBOL_GPL(device_store_ulong
);
730 ssize_t
device_show_ulong(struct device
*dev
,
731 struct device_attribute
*attr
,
734 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
735 return snprintf(buf
, PAGE_SIZE
, "%lx\n", *(unsigned long *)(ea
->var
));
737 EXPORT_SYMBOL_GPL(device_show_ulong
);
739 ssize_t
device_store_int(struct device
*dev
,
740 struct device_attribute
*attr
,
741 const char *buf
, size_t size
)
743 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
745 long new = simple_strtol(buf
, &end
, 0);
746 if (end
== buf
|| new > INT_MAX
|| new < INT_MIN
)
748 *(int *)(ea
->var
) = new;
749 /* Always return full write size even if we didn't consume all */
752 EXPORT_SYMBOL_GPL(device_store_int
);
754 ssize_t
device_show_int(struct device
*dev
,
755 struct device_attribute
*attr
,
758 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
760 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(int *)(ea
->var
));
762 EXPORT_SYMBOL_GPL(device_show_int
);
764 ssize_t
device_store_bool(struct device
*dev
, struct device_attribute
*attr
,
765 const char *buf
, size_t size
)
767 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
769 if (strtobool(buf
, ea
->var
) < 0)
774 EXPORT_SYMBOL_GPL(device_store_bool
);
776 ssize_t
device_show_bool(struct device
*dev
, struct device_attribute
*attr
,
779 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
781 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(bool *)(ea
->var
));
783 EXPORT_SYMBOL_GPL(device_show_bool
);
786 * device_release - free device structure.
787 * @kobj: device's kobject.
789 * This is called once the reference count for the object
790 * reaches 0. We forward the call to the device's release
791 * method, which should handle actually freeing the structure.
793 static void device_release(struct kobject
*kobj
)
795 struct device
*dev
= kobj_to_dev(kobj
);
796 struct device_private
*p
= dev
->p
;
799 * Some platform devices are driven without driver attached
800 * and managed resources may have been acquired. Make sure
801 * all resources are released.
803 * Drivers still can add resources into device after device
804 * is deleted but alive, so release devres here to avoid
805 * possible memory leak.
807 devres_release_all(dev
);
811 else if (dev
->type
&& dev
->type
->release
)
812 dev
->type
->release(dev
);
813 else if (dev
->class && dev
->class->dev_release
)
814 dev
->class->dev_release(dev
);
816 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
817 "function, it is broken and must be fixed.\n",
822 static const void *device_namespace(struct kobject
*kobj
)
824 struct device
*dev
= kobj_to_dev(kobj
);
825 const void *ns
= NULL
;
827 if (dev
->class && dev
->class->ns_type
)
828 ns
= dev
->class->namespace(dev
);
833 static struct kobj_type device_ktype
= {
834 .release
= device_release
,
835 .sysfs_ops
= &dev_sysfs_ops
,
836 .namespace = device_namespace
,
840 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
842 struct kobj_type
*ktype
= get_ktype(kobj
);
844 if (ktype
== &device_ktype
) {
845 struct device
*dev
= kobj_to_dev(kobj
);
854 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
856 struct device
*dev
= kobj_to_dev(kobj
);
859 return dev
->bus
->name
;
861 return dev
->class->name
;
865 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
866 struct kobj_uevent_env
*env
)
868 struct device
*dev
= kobj_to_dev(kobj
);
871 /* add device node properties if present */
872 if (MAJOR(dev
->devt
)) {
876 kuid_t uid
= GLOBAL_ROOT_UID
;
877 kgid_t gid
= GLOBAL_ROOT_GID
;
879 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
880 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
881 name
= device_get_devnode(dev
, &mode
, &uid
, &gid
, &tmp
);
883 add_uevent_var(env
, "DEVNAME=%s", name
);
885 add_uevent_var(env
, "DEVMODE=%#o", mode
& 0777);
886 if (!uid_eq(uid
, GLOBAL_ROOT_UID
))
887 add_uevent_var(env
, "DEVUID=%u", from_kuid(&init_user_ns
, uid
));
888 if (!gid_eq(gid
, GLOBAL_ROOT_GID
))
889 add_uevent_var(env
, "DEVGID=%u", from_kgid(&init_user_ns
, gid
));
894 if (dev
->type
&& dev
->type
->name
)
895 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
898 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
900 /* Add common DT information about the device */
901 of_device_uevent(dev
, env
);
903 /* have the bus specific function add its stuff */
904 if (dev
->bus
&& dev
->bus
->uevent
) {
905 retval
= dev
->bus
->uevent(dev
, env
);
907 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
908 dev_name(dev
), __func__
, retval
);
911 /* have the class specific function add its stuff */
912 if (dev
->class && dev
->class->dev_uevent
) {
913 retval
= dev
->class->dev_uevent(dev
, env
);
915 pr_debug("device: '%s': %s: class uevent() "
916 "returned %d\n", dev_name(dev
),
920 /* have the device type specific function add its stuff */
921 if (dev
->type
&& dev
->type
->uevent
) {
922 retval
= dev
->type
->uevent(dev
, env
);
924 pr_debug("device: '%s': %s: dev_type uevent() "
925 "returned %d\n", dev_name(dev
),
932 static const struct kset_uevent_ops device_uevent_ops
= {
933 .filter
= dev_uevent_filter
,
934 .name
= dev_uevent_name
,
935 .uevent
= dev_uevent
,
938 static ssize_t
uevent_show(struct device
*dev
, struct device_attribute
*attr
,
941 struct kobject
*top_kobj
;
943 struct kobj_uevent_env
*env
= NULL
;
948 /* search the kset, the device belongs to */
949 top_kobj
= &dev
->kobj
;
950 while (!top_kobj
->kset
&& top_kobj
->parent
)
951 top_kobj
= top_kobj
->parent
;
955 kset
= top_kobj
->kset
;
956 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
960 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
961 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
964 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
968 /* let the kset specific function add its keys */
969 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
973 /* copy keys to file */
974 for (i
= 0; i
< env
->envp_idx
; i
++)
975 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
981 static ssize_t
uevent_store(struct device
*dev
, struct device_attribute
*attr
,
982 const char *buf
, size_t count
)
984 if (kobject_synth_uevent(&dev
->kobj
, buf
, count
))
985 dev_err(dev
, "uevent: failed to send synthetic uevent\n");
989 static DEVICE_ATTR_RW(uevent
);
991 static ssize_t
online_show(struct device
*dev
, struct device_attribute
*attr
,
999 return sprintf(buf
, "%u\n", val
);
1002 static ssize_t
online_store(struct device
*dev
, struct device_attribute
*attr
,
1003 const char *buf
, size_t count
)
1008 ret
= strtobool(buf
, &val
);
1012 ret
= lock_device_hotplug_sysfs();
1016 ret
= val
? device_online(dev
) : device_offline(dev
);
1017 unlock_device_hotplug();
1018 return ret
< 0 ? ret
: count
;
1020 static DEVICE_ATTR_RW(online
);
1022 int device_add_groups(struct device
*dev
, const struct attribute_group
**groups
)
1024 return sysfs_create_groups(&dev
->kobj
, groups
);
1027 void device_remove_groups(struct device
*dev
,
1028 const struct attribute_group
**groups
)
1030 sysfs_remove_groups(&dev
->kobj
, groups
);
1033 static int device_add_attrs(struct device
*dev
)
1035 struct class *class = dev
->class;
1036 const struct device_type
*type
= dev
->type
;
1040 error
= device_add_groups(dev
, class->dev_groups
);
1046 error
= device_add_groups(dev
, type
->groups
);
1048 goto err_remove_class_groups
;
1051 error
= device_add_groups(dev
, dev
->groups
);
1053 goto err_remove_type_groups
;
1055 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
1056 error
= device_create_file(dev
, &dev_attr_online
);
1058 goto err_remove_dev_groups
;
1063 err_remove_dev_groups
:
1064 device_remove_groups(dev
, dev
->groups
);
1065 err_remove_type_groups
:
1067 device_remove_groups(dev
, type
->groups
);
1068 err_remove_class_groups
:
1070 device_remove_groups(dev
, class->dev_groups
);
1075 static void device_remove_attrs(struct device
*dev
)
1077 struct class *class = dev
->class;
1078 const struct device_type
*type
= dev
->type
;
1080 device_remove_file(dev
, &dev_attr_online
);
1081 device_remove_groups(dev
, dev
->groups
);
1084 device_remove_groups(dev
, type
->groups
);
1087 device_remove_groups(dev
, class->dev_groups
);
1090 static ssize_t
dev_show(struct device
*dev
, struct device_attribute
*attr
,
1093 return print_dev_t(buf
, dev
->devt
);
1095 static DEVICE_ATTR_RO(dev
);
1098 struct kset
*devices_kset
;
1101 * devices_kset_move_before - Move device in the devices_kset's list.
1102 * @deva: Device to move.
1103 * @devb: Device @deva should come before.
1105 static void devices_kset_move_before(struct device
*deva
, struct device
*devb
)
1109 pr_debug("devices_kset: Moving %s before %s\n",
1110 dev_name(deva
), dev_name(devb
));
1111 spin_lock(&devices_kset
->list_lock
);
1112 list_move_tail(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1113 spin_unlock(&devices_kset
->list_lock
);
1117 * devices_kset_move_after - Move device in the devices_kset's list.
1118 * @deva: Device to move
1119 * @devb: Device @deva should come after.
1121 static void devices_kset_move_after(struct device
*deva
, struct device
*devb
)
1125 pr_debug("devices_kset: Moving %s after %s\n",
1126 dev_name(deva
), dev_name(devb
));
1127 spin_lock(&devices_kset
->list_lock
);
1128 list_move(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1129 spin_unlock(&devices_kset
->list_lock
);
1133 * devices_kset_move_last - move the device to the end of devices_kset's list.
1134 * @dev: device to move
1136 void devices_kset_move_last(struct device
*dev
)
1140 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev
));
1141 spin_lock(&devices_kset
->list_lock
);
1142 list_move_tail(&dev
->kobj
.entry
, &devices_kset
->list
);
1143 spin_unlock(&devices_kset
->list_lock
);
1147 * device_create_file - create sysfs attribute file for device.
1149 * @attr: device attribute descriptor.
1151 int device_create_file(struct device
*dev
,
1152 const struct device_attribute
*attr
)
1157 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
1158 "Attribute %s: write permission without 'store'\n",
1160 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
1161 "Attribute %s: read permission without 'show'\n",
1163 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
1168 EXPORT_SYMBOL_GPL(device_create_file
);
1171 * device_remove_file - remove sysfs attribute file.
1173 * @attr: device attribute descriptor.
1175 void device_remove_file(struct device
*dev
,
1176 const struct device_attribute
*attr
)
1179 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
1181 EXPORT_SYMBOL_GPL(device_remove_file
);
1184 * device_remove_file_self - remove sysfs attribute file from its own method.
1186 * @attr: device attribute descriptor.
1188 * See kernfs_remove_self() for details.
1190 bool device_remove_file_self(struct device
*dev
,
1191 const struct device_attribute
*attr
)
1194 return sysfs_remove_file_self(&dev
->kobj
, &attr
->attr
);
1198 EXPORT_SYMBOL_GPL(device_remove_file_self
);
1201 * device_create_bin_file - create sysfs binary attribute file for device.
1203 * @attr: device binary attribute descriptor.
1205 int device_create_bin_file(struct device
*dev
,
1206 const struct bin_attribute
*attr
)
1208 int error
= -EINVAL
;
1210 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
1213 EXPORT_SYMBOL_GPL(device_create_bin_file
);
1216 * device_remove_bin_file - remove sysfs binary attribute file
1218 * @attr: device binary attribute descriptor.
1220 void device_remove_bin_file(struct device
*dev
,
1221 const struct bin_attribute
*attr
)
1224 sysfs_remove_bin_file(&dev
->kobj
, attr
);
1226 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
1228 static void klist_children_get(struct klist_node
*n
)
1230 struct device_private
*p
= to_device_private_parent(n
);
1231 struct device
*dev
= p
->device
;
1236 static void klist_children_put(struct klist_node
*n
)
1238 struct device_private
*p
= to_device_private_parent(n
);
1239 struct device
*dev
= p
->device
;
1245 * device_initialize - init device structure.
1248 * This prepares the device for use by other layers by initializing
1250 * It is the first half of device_register(), if called by
1251 * that function, though it can also be called separately, so one
1252 * may use @dev's fields. In particular, get_device()/put_device()
1253 * may be used for reference counting of @dev after calling this
1256 * All fields in @dev must be initialized by the caller to 0, except
1257 * for those explicitly set to some other value. The simplest
1258 * approach is to use kzalloc() to allocate the structure containing
1261 * NOTE: Use put_device() to give up your reference instead of freeing
1262 * @dev directly once you have called this function.
1264 void device_initialize(struct device
*dev
)
1266 dev
->kobj
.kset
= devices_kset
;
1267 kobject_init(&dev
->kobj
, &device_ktype
);
1268 INIT_LIST_HEAD(&dev
->dma_pools
);
1269 mutex_init(&dev
->mutex
);
1270 lockdep_set_novalidate_class(&dev
->mutex
);
1271 spin_lock_init(&dev
->devres_lock
);
1272 INIT_LIST_HEAD(&dev
->devres_head
);
1273 device_pm_init(dev
);
1274 set_dev_node(dev
, -1);
1275 #ifdef CONFIG_GENERIC_MSI_IRQ
1276 INIT_LIST_HEAD(&dev
->msi_list
);
1278 INIT_LIST_HEAD(&dev
->links
.consumers
);
1279 INIT_LIST_HEAD(&dev
->links
.suppliers
);
1280 dev
->links
.status
= DL_DEV_NO_DRIVER
;
1282 EXPORT_SYMBOL_GPL(device_initialize
);
1284 struct kobject
*virtual_device_parent(struct device
*dev
)
1286 static struct kobject
*virtual_dir
= NULL
;
1289 virtual_dir
= kobject_create_and_add("virtual",
1290 &devices_kset
->kobj
);
1296 struct kobject kobj
;
1297 struct class *class;
1300 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1302 static void class_dir_release(struct kobject
*kobj
)
1304 struct class_dir
*dir
= to_class_dir(kobj
);
1309 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
1311 struct class_dir
*dir
= to_class_dir(kobj
);
1312 return dir
->class->ns_type
;
1315 static struct kobj_type class_dir_ktype
= {
1316 .release
= class_dir_release
,
1317 .sysfs_ops
= &kobj_sysfs_ops
,
1318 .child_ns_type
= class_dir_child_ns_type
1321 static struct kobject
*
1322 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
1324 struct class_dir
*dir
;
1327 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1332 kobject_init(&dir
->kobj
, &class_dir_ktype
);
1334 dir
->kobj
.kset
= &class->p
->glue_dirs
;
1336 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
1338 kobject_put(&dir
->kobj
);
1344 static DEFINE_MUTEX(gdp_mutex
);
1346 static struct kobject
*get_device_parent(struct device
*dev
,
1347 struct device
*parent
)
1350 struct kobject
*kobj
= NULL
;
1351 struct kobject
*parent_kobj
;
1355 /* block disks show up in /sys/block */
1356 if (sysfs_deprecated
&& dev
->class == &block_class
) {
1357 if (parent
&& parent
->class == &block_class
)
1358 return &parent
->kobj
;
1359 return &block_class
.p
->subsys
.kobj
;
1364 * If we have no parent, we live in "virtual".
1365 * Class-devices with a non class-device as parent, live
1366 * in a "glue" directory to prevent namespace collisions.
1369 parent_kobj
= virtual_device_parent(dev
);
1370 else if (parent
->class && !dev
->class->ns_type
)
1371 return &parent
->kobj
;
1373 parent_kobj
= &parent
->kobj
;
1375 mutex_lock(&gdp_mutex
);
1377 /* find our class-directory at the parent and reference it */
1378 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
1379 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
1380 if (k
->parent
== parent_kobj
) {
1381 kobj
= kobject_get(k
);
1384 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
1386 mutex_unlock(&gdp_mutex
);
1390 /* or create a new class-directory at the parent device */
1391 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
1392 /* do not emit an uevent for this simple "glue" directory */
1393 mutex_unlock(&gdp_mutex
);
1397 /* subsystems can specify a default root directory for their devices */
1398 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
1399 return &dev
->bus
->dev_root
->kobj
;
1402 return &parent
->kobj
;
1406 static inline bool live_in_glue_dir(struct kobject
*kobj
,
1409 if (!kobj
|| !dev
->class ||
1410 kobj
->kset
!= &dev
->class->p
->glue_dirs
)
1415 static inline struct kobject
*get_glue_dir(struct device
*dev
)
1417 return dev
->kobj
.parent
;
1421 * make sure cleaning up dir as the last step, we need to make
1422 * sure .release handler of kobject is run with holding the
1425 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
1427 /* see if we live in a "glue" directory */
1428 if (!live_in_glue_dir(glue_dir
, dev
))
1431 mutex_lock(&gdp_mutex
);
1432 kobject_put(glue_dir
);
1433 mutex_unlock(&gdp_mutex
);
1436 static int device_add_class_symlinks(struct device
*dev
)
1438 struct device_node
*of_node
= dev_of_node(dev
);
1442 error
= sysfs_create_link(&dev
->kobj
, &of_node
->kobj
,"of_node");
1444 dev_warn(dev
, "Error %d creating of_node link\n",error
);
1445 /* An error here doesn't warrant bringing down the device */
1451 error
= sysfs_create_link(&dev
->kobj
,
1452 &dev
->class->p
->subsys
.kobj
,
1457 if (dev
->parent
&& device_is_not_partition(dev
)) {
1458 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
1465 /* /sys/block has directories and does not need symlinks */
1466 if (sysfs_deprecated
&& dev
->class == &block_class
)
1470 /* link in the class directory pointing to the device */
1471 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
1472 &dev
->kobj
, dev_name(dev
));
1479 sysfs_remove_link(&dev
->kobj
, "device");
1482 sysfs_remove_link(&dev
->kobj
, "subsystem");
1484 sysfs_remove_link(&dev
->kobj
, "of_node");
1488 static void device_remove_class_symlinks(struct device
*dev
)
1490 if (dev_of_node(dev
))
1491 sysfs_remove_link(&dev
->kobj
, "of_node");
1496 if (dev
->parent
&& device_is_not_partition(dev
))
1497 sysfs_remove_link(&dev
->kobj
, "device");
1498 sysfs_remove_link(&dev
->kobj
, "subsystem");
1500 if (sysfs_deprecated
&& dev
->class == &block_class
)
1503 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
1507 * dev_set_name - set a device name
1509 * @fmt: format string for the device's name
1511 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
1516 va_start(vargs
, fmt
);
1517 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
1521 EXPORT_SYMBOL_GPL(dev_set_name
);
1524 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1527 * By default we select char/ for new entries. Setting class->dev_obj
1528 * to NULL prevents an entry from being created. class->dev_kobj must
1529 * be set (or cleared) before any devices are registered to the class
1530 * otherwise device_create_sys_dev_entry() and
1531 * device_remove_sys_dev_entry() will disagree about the presence of
1534 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
1536 struct kobject
*kobj
;
1539 kobj
= dev
->class->dev_kobj
;
1541 kobj
= sysfs_dev_char_kobj
;
1546 static int device_create_sys_dev_entry(struct device
*dev
)
1548 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1553 format_dev_t(devt_str
, dev
->devt
);
1554 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
1560 static void device_remove_sys_dev_entry(struct device
*dev
)
1562 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1566 format_dev_t(devt_str
, dev
->devt
);
1567 sysfs_remove_link(kobj
, devt_str
);
1571 int device_private_init(struct device
*dev
)
1573 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1576 dev
->p
->device
= dev
;
1577 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1578 klist_children_put
);
1579 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1584 * device_add - add device to device hierarchy.
1587 * This is part 2 of device_register(), though may be called
1588 * separately _iff_ device_initialize() has been called separately.
1590 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1591 * to the global and sibling lists for the device, then
1592 * adds it to the other relevant subsystems of the driver model.
1594 * Do not call this routine or device_register() more than once for
1595 * any device structure. The driver model core is not designed to work
1596 * with devices that get unregistered and then spring back to life.
1597 * (Among other things, it's very hard to guarantee that all references
1598 * to the previous incarnation of @dev have been dropped.) Allocate
1599 * and register a fresh new struct device instead.
1601 * NOTE: _Never_ directly free @dev after calling this function, even
1602 * if it returned an error! Always use put_device() to give up your
1603 * reference instead.
1605 int device_add(struct device
*dev
)
1607 struct device
*parent
;
1608 struct kobject
*kobj
;
1609 struct class_interface
*class_intf
;
1610 int error
= -EINVAL
;
1611 struct kobject
*glue_dir
= NULL
;
1613 dev
= get_device(dev
);
1618 error
= device_private_init(dev
);
1624 * for statically allocated devices, which should all be converted
1625 * some day, we need to initialize the name. We prevent reading back
1626 * the name, and force the use of dev_name()
1628 if (dev
->init_name
) {
1629 dev_set_name(dev
, "%s", dev
->init_name
);
1630 dev
->init_name
= NULL
;
1633 /* subsystems can specify simple device enumeration */
1634 if (!dev_name(dev
) && dev
->bus
&& dev
->bus
->dev_name
)
1635 dev_set_name(dev
, "%s%u", dev
->bus
->dev_name
, dev
->id
);
1637 if (!dev_name(dev
)) {
1642 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1644 parent
= get_device(dev
->parent
);
1645 kobj
= get_device_parent(dev
, parent
);
1647 dev
->kobj
.parent
= kobj
;
1649 /* use parent numa_node */
1650 if (parent
&& (dev_to_node(dev
) == NUMA_NO_NODE
))
1651 set_dev_node(dev
, dev_to_node(parent
));
1653 /* first, register with generic layer. */
1654 /* we require the name to be set before, and pass NULL */
1655 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
1657 glue_dir
= get_glue_dir(dev
);
1661 /* notify platform of device entry */
1662 if (platform_notify
)
1663 platform_notify(dev
);
1665 error
= device_create_file(dev
, &dev_attr_uevent
);
1669 error
= device_add_class_symlinks(dev
);
1672 error
= device_add_attrs(dev
);
1675 error
= bus_add_device(dev
);
1678 error
= dpm_sysfs_add(dev
);
1683 if (MAJOR(dev
->devt
)) {
1684 error
= device_create_file(dev
, &dev_attr_dev
);
1688 error
= device_create_sys_dev_entry(dev
);
1692 devtmpfs_create_node(dev
);
1695 /* Notify clients of device addition. This call must come
1696 * after dpm_sysfs_add() and before kobject_uevent().
1699 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1700 BUS_NOTIFY_ADD_DEVICE
, dev
);
1702 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1703 bus_probe_device(dev
);
1705 klist_add_tail(&dev
->p
->knode_parent
,
1706 &parent
->p
->klist_children
);
1709 mutex_lock(&dev
->class->p
->mutex
);
1710 /* tie the class to the device */
1711 klist_add_tail(&dev
->knode_class
,
1712 &dev
->class->p
->klist_devices
);
1714 /* notify any interfaces that the device is here */
1715 list_for_each_entry(class_intf
,
1716 &dev
->class->p
->interfaces
, node
)
1717 if (class_intf
->add_dev
)
1718 class_intf
->add_dev(dev
, class_intf
);
1719 mutex_unlock(&dev
->class->p
->mutex
);
1725 if (MAJOR(dev
->devt
))
1726 device_remove_file(dev
, &dev_attr_dev
);
1728 device_pm_remove(dev
);
1729 dpm_sysfs_remove(dev
);
1731 bus_remove_device(dev
);
1733 device_remove_attrs(dev
);
1735 device_remove_class_symlinks(dev
);
1737 device_remove_file(dev
, &dev_attr_uevent
);
1739 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1740 glue_dir
= get_glue_dir(dev
);
1741 kobject_del(&dev
->kobj
);
1743 cleanup_glue_dir(dev
, glue_dir
);
1750 EXPORT_SYMBOL_GPL(device_add
);
1753 * device_register - register a device with the system.
1754 * @dev: pointer to the device structure
1756 * This happens in two clean steps - initialize the device
1757 * and add it to the system. The two steps can be called
1758 * separately, but this is the easiest and most common.
1759 * I.e. you should only call the two helpers separately if
1760 * have a clearly defined need to use and refcount the device
1761 * before it is added to the hierarchy.
1763 * For more information, see the kerneldoc for device_initialize()
1766 * NOTE: _Never_ directly free @dev after calling this function, even
1767 * if it returned an error! Always use put_device() to give up the
1768 * reference initialized in this function instead.
1770 int device_register(struct device
*dev
)
1772 device_initialize(dev
);
1773 return device_add(dev
);
1775 EXPORT_SYMBOL_GPL(device_register
);
1778 * get_device - increment reference count for device.
1781 * This simply forwards the call to kobject_get(), though
1782 * we do take care to provide for the case that we get a NULL
1783 * pointer passed in.
1785 struct device
*get_device(struct device
*dev
)
1787 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1789 EXPORT_SYMBOL_GPL(get_device
);
1792 * put_device - decrement reference count.
1793 * @dev: device in question.
1795 void put_device(struct device
*dev
)
1797 /* might_sleep(); */
1799 kobject_put(&dev
->kobj
);
1801 EXPORT_SYMBOL_GPL(put_device
);
1804 * device_del - delete device from system.
1807 * This is the first part of the device unregistration
1808 * sequence. This removes the device from the lists we control
1809 * from here, has it removed from the other driver model
1810 * subsystems it was added to in device_add(), and removes it
1811 * from the kobject hierarchy.
1813 * NOTE: this should be called manually _iff_ device_add() was
1814 * also called manually.
1816 void device_del(struct device
*dev
)
1818 struct device
*parent
= dev
->parent
;
1819 struct kobject
*glue_dir
= NULL
;
1820 struct class_interface
*class_intf
;
1822 /* Notify clients of device removal. This call must come
1823 * before dpm_sysfs_remove().
1826 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1827 BUS_NOTIFY_DEL_DEVICE
, dev
);
1829 device_links_purge(dev
);
1830 dpm_sysfs_remove(dev
);
1832 klist_del(&dev
->p
->knode_parent
);
1833 if (MAJOR(dev
->devt
)) {
1834 devtmpfs_delete_node(dev
);
1835 device_remove_sys_dev_entry(dev
);
1836 device_remove_file(dev
, &dev_attr_dev
);
1839 device_remove_class_symlinks(dev
);
1841 mutex_lock(&dev
->class->p
->mutex
);
1842 /* notify any interfaces that the device is now gone */
1843 list_for_each_entry(class_intf
,
1844 &dev
->class->p
->interfaces
, node
)
1845 if (class_intf
->remove_dev
)
1846 class_intf
->remove_dev(dev
, class_intf
);
1847 /* remove the device from the class list */
1848 klist_del(&dev
->knode_class
);
1849 mutex_unlock(&dev
->class->p
->mutex
);
1851 device_remove_file(dev
, &dev_attr_uevent
);
1852 device_remove_attrs(dev
);
1853 bus_remove_device(dev
);
1854 device_pm_remove(dev
);
1855 driver_deferred_probe_del(dev
);
1856 device_remove_properties(dev
);
1858 /* Notify the platform of the removal, in case they
1859 * need to do anything...
1861 if (platform_notify_remove
)
1862 platform_notify_remove(dev
);
1864 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1865 BUS_NOTIFY_REMOVED_DEVICE
, dev
);
1866 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1867 glue_dir
= get_glue_dir(dev
);
1868 kobject_del(&dev
->kobj
);
1869 cleanup_glue_dir(dev
, glue_dir
);
1872 EXPORT_SYMBOL_GPL(device_del
);
1875 * device_unregister - unregister device from system.
1876 * @dev: device going away.
1878 * We do this in two parts, like we do device_register(). First,
1879 * we remove it from all the subsystems with device_del(), then
1880 * we decrement the reference count via put_device(). If that
1881 * is the final reference count, the device will be cleaned up
1882 * via device_release() above. Otherwise, the structure will
1883 * stick around until the final reference to the device is dropped.
1885 void device_unregister(struct device
*dev
)
1887 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1891 EXPORT_SYMBOL_GPL(device_unregister
);
1893 static struct device
*prev_device(struct klist_iter
*i
)
1895 struct klist_node
*n
= klist_prev(i
);
1896 struct device
*dev
= NULL
;
1897 struct device_private
*p
;
1900 p
= to_device_private_parent(n
);
1906 static struct device
*next_device(struct klist_iter
*i
)
1908 struct klist_node
*n
= klist_next(i
);
1909 struct device
*dev
= NULL
;
1910 struct device_private
*p
;
1913 p
= to_device_private_parent(n
);
1920 * device_get_devnode - path of device node file
1922 * @mode: returned file access mode
1923 * @uid: returned file owner
1924 * @gid: returned file group
1925 * @tmp: possibly allocated string
1927 * Return the relative path of a possible device node.
1928 * Non-default names may need to allocate a memory to compose
1929 * a name. This memory is returned in tmp and needs to be
1930 * freed by the caller.
1932 const char *device_get_devnode(struct device
*dev
,
1933 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
1940 /* the device type may provide a specific name */
1941 if (dev
->type
&& dev
->type
->devnode
)
1942 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
1946 /* the class may provide a specific name */
1947 if (dev
->class && dev
->class->devnode
)
1948 *tmp
= dev
->class->devnode(dev
, mode
);
1952 /* return name without allocation, tmp == NULL */
1953 if (strchr(dev_name(dev
), '!') == NULL
)
1954 return dev_name(dev
);
1956 /* replace '!' in the name with '/' */
1957 s
= kstrdup(dev_name(dev
), GFP_KERNEL
);
1960 strreplace(s
, '!', '/');
1965 * device_for_each_child - device child iterator.
1966 * @parent: parent struct device.
1967 * @fn: function to be called for each device.
1968 * @data: data for the callback.
1970 * Iterate over @parent's child devices, and call @fn for each,
1973 * We check the return of @fn each time. If it returns anything
1974 * other than 0, we break out and return that value.
1976 int device_for_each_child(struct device
*parent
, void *data
,
1977 int (*fn
)(struct device
*dev
, void *data
))
1979 struct klist_iter i
;
1980 struct device
*child
;
1986 klist_iter_init(&parent
->p
->klist_children
, &i
);
1987 while ((child
= next_device(&i
)) && !error
)
1988 error
= fn(child
, data
);
1989 klist_iter_exit(&i
);
1992 EXPORT_SYMBOL_GPL(device_for_each_child
);
1995 * device_for_each_child_reverse - device child iterator in reversed order.
1996 * @parent: parent struct device.
1997 * @fn: function to be called for each device.
1998 * @data: data for the callback.
2000 * Iterate over @parent's child devices, and call @fn for each,
2003 * We check the return of @fn each time. If it returns anything
2004 * other than 0, we break out and return that value.
2006 int device_for_each_child_reverse(struct device
*parent
, void *data
,
2007 int (*fn
)(struct device
*dev
, void *data
))
2009 struct klist_iter i
;
2010 struct device
*child
;
2016 klist_iter_init(&parent
->p
->klist_children
, &i
);
2017 while ((child
= prev_device(&i
)) && !error
)
2018 error
= fn(child
, data
);
2019 klist_iter_exit(&i
);
2022 EXPORT_SYMBOL_GPL(device_for_each_child_reverse
);
2025 * device_find_child - device iterator for locating a particular device.
2026 * @parent: parent struct device
2027 * @match: Callback function to check device
2028 * @data: Data to pass to match function
2030 * This is similar to the device_for_each_child() function above, but it
2031 * returns a reference to a device that is 'found' for later use, as
2032 * determined by the @match callback.
2034 * The callback should return 0 if the device doesn't match and non-zero
2035 * if it does. If the callback returns non-zero and a reference to the
2036 * current device can be obtained, this function will return to the caller
2037 * and not iterate over any more devices.
2039 * NOTE: you will need to drop the reference with put_device() after use.
2041 struct device
*device_find_child(struct device
*parent
, void *data
,
2042 int (*match
)(struct device
*dev
, void *data
))
2044 struct klist_iter i
;
2045 struct device
*child
;
2050 klist_iter_init(&parent
->p
->klist_children
, &i
);
2051 while ((child
= next_device(&i
)))
2052 if (match(child
, data
) && get_device(child
))
2054 klist_iter_exit(&i
);
2057 EXPORT_SYMBOL_GPL(device_find_child
);
2059 int __init
devices_init(void)
2061 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
2064 dev_kobj
= kobject_create_and_add("dev", NULL
);
2067 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
2068 if (!sysfs_dev_block_kobj
)
2069 goto block_kobj_err
;
2070 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
2071 if (!sysfs_dev_char_kobj
)
2077 kobject_put(sysfs_dev_block_kobj
);
2079 kobject_put(dev_kobj
);
2081 kset_unregister(devices_kset
);
2085 static int device_check_offline(struct device
*dev
, void *not_used
)
2089 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2093 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
2097 * device_offline - Prepare the device for hot-removal.
2098 * @dev: Device to be put offline.
2100 * Execute the device bus type's .offline() callback, if present, to prepare
2101 * the device for a subsequent hot-removal. If that succeeds, the device must
2102 * not be used until either it is removed or its bus type's .online() callback
2105 * Call under device_hotplug_lock.
2107 int device_offline(struct device
*dev
)
2111 if (dev
->offline_disabled
)
2114 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2119 if (device_supports_offline(dev
)) {
2123 ret
= dev
->bus
->offline(dev
);
2125 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
2126 dev
->offline
= true;
2136 * device_online - Put the device back online after successful device_offline().
2137 * @dev: Device to be put back online.
2139 * If device_offline() has been successfully executed for @dev, but the device
2140 * has not been removed subsequently, execute its bus type's .online() callback
2141 * to indicate that the device can be used again.
2143 * Call under device_hotplug_lock.
2145 int device_online(struct device
*dev
)
2150 if (device_supports_offline(dev
)) {
2152 ret
= dev
->bus
->online(dev
);
2154 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
2155 dev
->offline
= false;
2166 struct root_device
{
2168 struct module
*owner
;
2171 static inline struct root_device
*to_root_device(struct device
*d
)
2173 return container_of(d
, struct root_device
, dev
);
2176 static void root_device_release(struct device
*dev
)
2178 kfree(to_root_device(dev
));
2182 * __root_device_register - allocate and register a root device
2183 * @name: root device name
2184 * @owner: owner module of the root device, usually THIS_MODULE
2186 * This function allocates a root device and registers it
2187 * using device_register(). In order to free the returned
2188 * device, use root_device_unregister().
2190 * Root devices are dummy devices which allow other devices
2191 * to be grouped under /sys/devices. Use this function to
2192 * allocate a root device and then use it as the parent of
2193 * any device which should appear under /sys/devices/{name}
2195 * The /sys/devices/{name} directory will also contain a
2196 * 'module' symlink which points to the @owner directory
2199 * Returns &struct device pointer on success, or ERR_PTR() on error.
2201 * Note: You probably want to use root_device_register().
2203 struct device
*__root_device_register(const char *name
, struct module
*owner
)
2205 struct root_device
*root
;
2208 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
2210 return ERR_PTR(err
);
2212 err
= dev_set_name(&root
->dev
, "%s", name
);
2215 return ERR_PTR(err
);
2218 root
->dev
.release
= root_device_release
;
2220 err
= device_register(&root
->dev
);
2222 put_device(&root
->dev
);
2223 return ERR_PTR(err
);
2226 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2228 struct module_kobject
*mk
= &owner
->mkobj
;
2230 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
2232 device_unregister(&root
->dev
);
2233 return ERR_PTR(err
);
2235 root
->owner
= owner
;
2241 EXPORT_SYMBOL_GPL(__root_device_register
);
2244 * root_device_unregister - unregister and free a root device
2245 * @dev: device going away
2247 * This function unregisters and cleans up a device that was created by
2248 * root_device_register().
2250 void root_device_unregister(struct device
*dev
)
2252 struct root_device
*root
= to_root_device(dev
);
2255 sysfs_remove_link(&root
->dev
.kobj
, "module");
2257 device_unregister(dev
);
2259 EXPORT_SYMBOL_GPL(root_device_unregister
);
2262 static void device_create_release(struct device
*dev
)
2264 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
2268 static struct device
*
2269 device_create_groups_vargs(struct class *class, struct device
*parent
,
2270 dev_t devt
, void *drvdata
,
2271 const struct attribute_group
**groups
,
2272 const char *fmt
, va_list args
)
2274 struct device
*dev
= NULL
;
2275 int retval
= -ENODEV
;
2277 if (class == NULL
|| IS_ERR(class))
2280 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
2286 device_initialize(dev
);
2289 dev
->parent
= parent
;
2290 dev
->groups
= groups
;
2291 dev
->release
= device_create_release
;
2292 dev_set_drvdata(dev
, drvdata
);
2294 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
2298 retval
= device_add(dev
);
2306 return ERR_PTR(retval
);
2310 * device_create_vargs - creates a device and registers it with sysfs
2311 * @class: pointer to the struct class that this device should be registered to
2312 * @parent: pointer to the parent struct device of this new device, if any
2313 * @devt: the dev_t for the char device to be added
2314 * @drvdata: the data to be added to the device for callbacks
2315 * @fmt: string for the device's name
2316 * @args: va_list for the device's name
2318 * This function can be used by char device classes. A struct device
2319 * will be created in sysfs, registered to the specified class.
2321 * A "dev" file will be created, showing the dev_t for the device, if
2322 * the dev_t is not 0,0.
2323 * If a pointer to a parent struct device is passed in, the newly created
2324 * struct device will be a child of that device in sysfs.
2325 * The pointer to the struct device will be returned from the call.
2326 * Any further sysfs files that might be required can be created using this
2329 * Returns &struct device pointer on success, or ERR_PTR() on error.
2331 * Note: the struct class passed to this function must have previously
2332 * been created with a call to class_create().
2334 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
2335 dev_t devt
, void *drvdata
, const char *fmt
,
2338 return device_create_groups_vargs(class, parent
, devt
, drvdata
, NULL
,
2341 EXPORT_SYMBOL_GPL(device_create_vargs
);
2344 * device_create - creates a device and registers it with sysfs
2345 * @class: pointer to the struct class that this device should be registered to
2346 * @parent: pointer to the parent struct device of this new device, if any
2347 * @devt: the dev_t for the char device to be added
2348 * @drvdata: the data to be added to the device for callbacks
2349 * @fmt: string for the device's name
2351 * This function can be used by char device classes. A struct device
2352 * will be created in sysfs, registered to the specified class.
2354 * A "dev" file will be created, showing the dev_t for the device, if
2355 * the dev_t is not 0,0.
2356 * If a pointer to a parent struct device is passed in, the newly created
2357 * struct device will be a child of that device in sysfs.
2358 * The pointer to the struct device will be returned from the call.
2359 * Any further sysfs files that might be required can be created using this
2362 * Returns &struct device pointer on success, or ERR_PTR() on error.
2364 * Note: the struct class passed to this function must have previously
2365 * been created with a call to class_create().
2367 struct device
*device_create(struct class *class, struct device
*parent
,
2368 dev_t devt
, void *drvdata
, const char *fmt
, ...)
2373 va_start(vargs
, fmt
);
2374 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
2378 EXPORT_SYMBOL_GPL(device_create
);
2381 * device_create_with_groups - creates a device and registers it with sysfs
2382 * @class: pointer to the struct class that this device should be registered to
2383 * @parent: pointer to the parent struct device of this new device, if any
2384 * @devt: the dev_t for the char device to be added
2385 * @drvdata: the data to be added to the device for callbacks
2386 * @groups: NULL-terminated list of attribute groups to be created
2387 * @fmt: string for the device's name
2389 * This function can be used by char device classes. A struct device
2390 * will be created in sysfs, registered to the specified class.
2391 * Additional attributes specified in the groups parameter will also
2392 * be created automatically.
2394 * A "dev" file will be created, showing the dev_t for the device, if
2395 * the dev_t is not 0,0.
2396 * If a pointer to a parent struct device is passed in, the newly created
2397 * struct device will be a child of that device in sysfs.
2398 * The pointer to the struct device will be returned from the call.
2399 * Any further sysfs files that might be required can be created using this
2402 * Returns &struct device pointer on success, or ERR_PTR() on error.
2404 * Note: the struct class passed to this function must have previously
2405 * been created with a call to class_create().
2407 struct device
*device_create_with_groups(struct class *class,
2408 struct device
*parent
, dev_t devt
,
2410 const struct attribute_group
**groups
,
2411 const char *fmt
, ...)
2416 va_start(vargs
, fmt
);
2417 dev
= device_create_groups_vargs(class, parent
, devt
, drvdata
, groups
,
2422 EXPORT_SYMBOL_GPL(device_create_with_groups
);
2424 static int __match_devt(struct device
*dev
, const void *data
)
2426 const dev_t
*devt
= data
;
2428 return dev
->devt
== *devt
;
2432 * device_destroy - removes a device that was created with device_create()
2433 * @class: pointer to the struct class that this device was registered with
2434 * @devt: the dev_t of the device that was previously registered
2436 * This call unregisters and cleans up a device that was created with a
2437 * call to device_create().
2439 void device_destroy(struct class *class, dev_t devt
)
2443 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
2446 device_unregister(dev
);
2449 EXPORT_SYMBOL_GPL(device_destroy
);
2452 * device_rename - renames a device
2453 * @dev: the pointer to the struct device to be renamed
2454 * @new_name: the new name of the device
2456 * It is the responsibility of the caller to provide mutual
2457 * exclusion between two different calls of device_rename
2458 * on the same device to ensure that new_name is valid and
2459 * won't conflict with other devices.
2461 * Note: Don't call this function. Currently, the networking layer calls this
2462 * function, but that will change. The following text from Kay Sievers offers
2465 * Renaming devices is racy at many levels, symlinks and other stuff are not
2466 * replaced atomically, and you get a "move" uevent, but it's not easy to
2467 * connect the event to the old and new device. Device nodes are not renamed at
2468 * all, there isn't even support for that in the kernel now.
2470 * In the meantime, during renaming, your target name might be taken by another
2471 * driver, creating conflicts. Or the old name is taken directly after you
2472 * renamed it -- then you get events for the same DEVPATH, before you even see
2473 * the "move" event. It's just a mess, and nothing new should ever rely on
2474 * kernel device renaming. Besides that, it's not even implemented now for
2475 * other things than (driver-core wise very simple) network devices.
2477 * We are currently about to change network renaming in udev to completely
2478 * disallow renaming of devices in the same namespace as the kernel uses,
2479 * because we can't solve the problems properly, that arise with swapping names
2480 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2481 * be allowed to some other name than eth[0-9]*, for the aforementioned
2484 * Make up a "real" name in the driver before you register anything, or add
2485 * some other attributes for userspace to find the device, or use udev to add
2486 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2487 * don't even want to get into that and try to implement the missing pieces in
2488 * the core. We really have other pieces to fix in the driver core mess. :)
2490 int device_rename(struct device
*dev
, const char *new_name
)
2492 struct kobject
*kobj
= &dev
->kobj
;
2493 char *old_device_name
= NULL
;
2496 dev
= get_device(dev
);
2500 dev_dbg(dev
, "renaming to %s\n", new_name
);
2502 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
2503 if (!old_device_name
) {
2509 error
= sysfs_rename_link_ns(&dev
->class->p
->subsys
.kobj
,
2510 kobj
, old_device_name
,
2511 new_name
, kobject_namespace(kobj
));
2516 error
= kobject_rename(kobj
, new_name
);
2523 kfree(old_device_name
);
2527 EXPORT_SYMBOL_GPL(device_rename
);
2529 static int device_move_class_links(struct device
*dev
,
2530 struct device
*old_parent
,
2531 struct device
*new_parent
)
2536 sysfs_remove_link(&dev
->kobj
, "device");
2538 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
2544 * device_move - moves a device to a new parent
2545 * @dev: the pointer to the struct device to be moved
2546 * @new_parent: the new parent of the device (can by NULL)
2547 * @dpm_order: how to reorder the dpm_list
2549 int device_move(struct device
*dev
, struct device
*new_parent
,
2550 enum dpm_order dpm_order
)
2553 struct device
*old_parent
;
2554 struct kobject
*new_parent_kobj
;
2556 dev
= get_device(dev
);
2561 new_parent
= get_device(new_parent
);
2562 new_parent_kobj
= get_device_parent(dev
, new_parent
);
2564 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
2565 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
2566 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
2568 cleanup_glue_dir(dev
, new_parent_kobj
);
2569 put_device(new_parent
);
2572 old_parent
= dev
->parent
;
2573 dev
->parent
= new_parent
;
2575 klist_remove(&dev
->p
->knode_parent
);
2577 klist_add_tail(&dev
->p
->knode_parent
,
2578 &new_parent
->p
->klist_children
);
2579 set_dev_node(dev
, dev_to_node(new_parent
));
2583 error
= device_move_class_links(dev
, old_parent
, new_parent
);
2585 /* We ignore errors on cleanup since we're hosed anyway... */
2586 device_move_class_links(dev
, new_parent
, old_parent
);
2587 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
2589 klist_remove(&dev
->p
->knode_parent
);
2590 dev
->parent
= old_parent
;
2592 klist_add_tail(&dev
->p
->knode_parent
,
2593 &old_parent
->p
->klist_children
);
2594 set_dev_node(dev
, dev_to_node(old_parent
));
2597 cleanup_glue_dir(dev
, new_parent_kobj
);
2598 put_device(new_parent
);
2602 switch (dpm_order
) {
2603 case DPM_ORDER_NONE
:
2605 case DPM_ORDER_DEV_AFTER_PARENT
:
2606 device_pm_move_after(dev
, new_parent
);
2607 devices_kset_move_after(dev
, new_parent
);
2609 case DPM_ORDER_PARENT_BEFORE_DEV
:
2610 device_pm_move_before(new_parent
, dev
);
2611 devices_kset_move_before(new_parent
, dev
);
2613 case DPM_ORDER_DEV_LAST
:
2614 device_pm_move_last(dev
);
2615 devices_kset_move_last(dev
);
2619 put_device(old_parent
);
2625 EXPORT_SYMBOL_GPL(device_move
);
2628 * device_shutdown - call ->shutdown() on each device to shutdown.
2630 void device_shutdown(void)
2632 struct device
*dev
, *parent
;
2634 spin_lock(&devices_kset
->list_lock
);
2636 * Walk the devices list backward, shutting down each in turn.
2637 * Beware that device unplug events may also start pulling
2638 * devices offline, even as the system is shutting down.
2640 while (!list_empty(&devices_kset
->list
)) {
2641 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
2645 * hold reference count of device's parent to
2646 * prevent it from being freed because parent's
2647 * lock is to be held
2649 parent
= get_device(dev
->parent
);
2652 * Make sure the device is off the kset list, in the
2653 * event that dev->*->shutdown() doesn't remove it.
2655 list_del_init(&dev
->kobj
.entry
);
2656 spin_unlock(&devices_kset
->list_lock
);
2658 /* hold lock to avoid race with probe/release */
2660 device_lock(parent
);
2663 /* Don't allow any more runtime suspends */
2664 pm_runtime_get_noresume(dev
);
2665 pm_runtime_barrier(dev
);
2667 if (dev
->class && dev
->class->shutdown
) {
2669 dev_info(dev
, "shutdown\n");
2670 dev
->class->shutdown(dev
);
2671 } else if (dev
->bus
&& dev
->bus
->shutdown
) {
2673 dev_info(dev
, "shutdown\n");
2674 dev
->bus
->shutdown(dev
);
2675 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2677 dev_info(dev
, "shutdown\n");
2678 dev
->driver
->shutdown(dev
);
2683 device_unlock(parent
);
2688 spin_lock(&devices_kset
->list_lock
);
2690 spin_unlock(&devices_kset
->list_lock
);
2694 * Device logging functions
2697 #ifdef CONFIG_PRINTK
2699 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2705 subsys
= dev
->class->name
;
2707 subsys
= dev
->bus
->name
;
2711 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2716 * Add device identifier DEVICE=:
2720 * +sound:card0 subsystem:devname
2722 if (MAJOR(dev
->devt
)) {
2725 if (strcmp(subsys
, "block") == 0)
2730 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2732 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2733 } else if (strcmp(subsys
, "net") == 0) {
2734 struct net_device
*net
= to_net_dev(dev
);
2737 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2738 "DEVICE=n%u", net
->ifindex
);
2741 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2742 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2751 dev_WARN(dev
, "device/subsystem name too long");
2755 int dev_vprintk_emit(int level
, const struct device
*dev
,
2756 const char *fmt
, va_list args
)
2761 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2763 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2765 EXPORT_SYMBOL(dev_vprintk_emit
);
2767 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2772 va_start(args
, fmt
);
2774 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2780 EXPORT_SYMBOL(dev_printk_emit
);
2782 static void __dev_printk(const char *level
, const struct device
*dev
,
2783 struct va_format
*vaf
)
2786 dev_printk_emit(level
[1] - '0', dev
, "%s %s: %pV",
2787 dev_driver_string(dev
), dev_name(dev
), vaf
);
2789 printk("%s(NULL device *): %pV", level
, vaf
);
2792 void dev_printk(const char *level
, const struct device
*dev
,
2793 const char *fmt
, ...)
2795 struct va_format vaf
;
2798 va_start(args
, fmt
);
2803 __dev_printk(level
, dev
, &vaf
);
2807 EXPORT_SYMBOL(dev_printk
);
2809 #define define_dev_printk_level(func, kern_level) \
2810 void func(const struct device *dev, const char *fmt, ...) \
2812 struct va_format vaf; \
2815 va_start(args, fmt); \
2820 __dev_printk(kern_level, dev, &vaf); \
2824 EXPORT_SYMBOL(func);
2826 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
2827 define_dev_printk_level(dev_alert
, KERN_ALERT
);
2828 define_dev_printk_level(dev_crit
, KERN_CRIT
);
2829 define_dev_printk_level(dev_err
, KERN_ERR
);
2830 define_dev_printk_level(dev_warn
, KERN_WARNING
);
2831 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
2832 define_dev_printk_level(_dev_info
, KERN_INFO
);
2836 static inline bool fwnode_is_primary(struct fwnode_handle
*fwnode
)
2838 return fwnode
&& !IS_ERR(fwnode
->secondary
);
2842 * set_primary_fwnode - Change the primary firmware node of a given device.
2843 * @dev: Device to handle.
2844 * @fwnode: New primary firmware node of the device.
2846 * Set the device's firmware node pointer to @fwnode, but if a secondary
2847 * firmware node of the device is present, preserve it.
2849 void set_primary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2852 struct fwnode_handle
*fn
= dev
->fwnode
;
2854 if (fwnode_is_primary(fn
))
2858 WARN_ON(fwnode
->secondary
);
2859 fwnode
->secondary
= fn
;
2861 dev
->fwnode
= fwnode
;
2863 dev
->fwnode
= fwnode_is_primary(dev
->fwnode
) ?
2864 dev
->fwnode
->secondary
: NULL
;
2867 EXPORT_SYMBOL_GPL(set_primary_fwnode
);
2870 * set_secondary_fwnode - Change the secondary firmware node of a given device.
2871 * @dev: Device to handle.
2872 * @fwnode: New secondary firmware node of the device.
2874 * If a primary firmware node of the device is present, set its secondary
2875 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
2878 void set_secondary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2881 fwnode
->secondary
= ERR_PTR(-ENODEV
);
2883 if (fwnode_is_primary(dev
->fwnode
))
2884 dev
->fwnode
->secondary
= fwnode
;
2886 dev
->fwnode
= fwnode
;
2890 * device_set_of_node_from_dev - reuse device-tree node of another device
2891 * @dev: device whose device-tree node is being set
2892 * @dev2: device whose device-tree node is being reused
2894 * Takes another reference to the new device-tree node after first dropping
2895 * any reference held to the old node.
2897 void device_set_of_node_from_dev(struct device
*dev
, const struct device
*dev2
)
2899 of_node_put(dev
->of_node
);
2900 dev
->of_node
= of_node_get(dev2
->of_node
);
2901 dev
->of_node_reused
= true;
2903 EXPORT_SYMBOL_GPL(device_set_of_node_from_dev
);