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 enum kobject_action action
;
986 if (kobject_action_type(buf
, count
, &action
) == 0)
987 kobject_uevent(&dev
->kobj
, action
);
989 dev_err(dev
, "uevent: unknown action-string\n");
992 static DEVICE_ATTR_RW(uevent
);
994 static ssize_t
online_show(struct device
*dev
, struct device_attribute
*attr
,
1000 val
= !dev
->offline
;
1002 return sprintf(buf
, "%u\n", val
);
1005 static ssize_t
online_store(struct device
*dev
, struct device_attribute
*attr
,
1006 const char *buf
, size_t count
)
1011 ret
= strtobool(buf
, &val
);
1015 ret
= lock_device_hotplug_sysfs();
1019 ret
= val
? device_online(dev
) : device_offline(dev
);
1020 unlock_device_hotplug();
1021 return ret
< 0 ? ret
: count
;
1023 static DEVICE_ATTR_RW(online
);
1025 int device_add_groups(struct device
*dev
, const struct attribute_group
**groups
)
1027 return sysfs_create_groups(&dev
->kobj
, groups
);
1029 EXPORT_SYMBOL_GPL(device_add_groups
);
1031 void device_remove_groups(struct device
*dev
,
1032 const struct attribute_group
**groups
)
1034 sysfs_remove_groups(&dev
->kobj
, groups
);
1036 EXPORT_SYMBOL_GPL(device_remove_groups
);
1038 union device_attr_group_devres
{
1039 const struct attribute_group
*group
;
1040 const struct attribute_group
**groups
;
1043 static int devm_attr_group_match(struct device
*dev
, void *res
, void *data
)
1045 return ((union device_attr_group_devres
*)res
)->group
== data
;
1048 static void devm_attr_group_remove(struct device
*dev
, void *res
)
1050 union device_attr_group_devres
*devres
= res
;
1051 const struct attribute_group
*group
= devres
->group
;
1053 dev_dbg(dev
, "%s: removing group %p\n", __func__
, group
);
1054 sysfs_remove_group(&dev
->kobj
, group
);
1057 static void devm_attr_groups_remove(struct device
*dev
, void *res
)
1059 union device_attr_group_devres
*devres
= res
;
1060 const struct attribute_group
**groups
= devres
->groups
;
1062 dev_dbg(dev
, "%s: removing groups %p\n", __func__
, groups
);
1063 sysfs_remove_groups(&dev
->kobj
, groups
);
1067 * devm_device_add_group - given a device, create a managed attribute group
1068 * @dev: The device to create the group for
1069 * @grp: The attribute group to create
1071 * This function creates a group for the first time. It will explicitly
1072 * warn and error if any of the attribute files being created already exist.
1074 * Returns 0 on success or error code on failure.
1076 int devm_device_add_group(struct device
*dev
, const struct attribute_group
*grp
)
1078 union device_attr_group_devres
*devres
;
1081 devres
= devres_alloc(devm_attr_group_remove
,
1082 sizeof(*devres
), GFP_KERNEL
);
1086 error
= sysfs_create_group(&dev
->kobj
, grp
);
1088 devres_free(devres
);
1092 devres
->group
= grp
;
1093 devres_add(dev
, devres
);
1096 EXPORT_SYMBOL_GPL(devm_device_add_group
);
1099 * devm_device_remove_group: remove a managed group from a device
1100 * @dev: device to remove the group from
1101 * @grp: group to remove
1103 * This function removes a group of attributes from a device. The attributes
1104 * previously have to have been created for this group, otherwise it will fail.
1106 void devm_device_remove_group(struct device
*dev
,
1107 const struct attribute_group
*grp
)
1109 WARN_ON(devres_release(dev
, devm_attr_group_remove
,
1110 devm_attr_group_match
,
1111 /* cast away const */ (void *)grp
));
1113 EXPORT_SYMBOL_GPL(devm_device_remove_group
);
1116 * devm_device_add_groups - create a bunch of managed attribute groups
1117 * @dev: The device to create the group for
1118 * @groups: The attribute groups to create, NULL terminated
1120 * This function creates a bunch of managed attribute groups. If an error
1121 * occurs when creating a group, all previously created groups will be
1122 * removed, unwinding everything back to the original state when this
1123 * function was called. It will explicitly warn and error if any of the
1124 * attribute files being created already exist.
1126 * Returns 0 on success or error code from sysfs_create_group on failure.
1128 int devm_device_add_groups(struct device
*dev
,
1129 const struct attribute_group
**groups
)
1131 union device_attr_group_devres
*devres
;
1134 devres
= devres_alloc(devm_attr_groups_remove
,
1135 sizeof(*devres
), GFP_KERNEL
);
1139 error
= sysfs_create_groups(&dev
->kobj
, groups
);
1141 devres_free(devres
);
1145 devres
->groups
= groups
;
1146 devres_add(dev
, devres
);
1149 EXPORT_SYMBOL_GPL(devm_device_add_groups
);
1152 * devm_device_remove_groups - remove a list of managed groups
1154 * @dev: The device for the groups to be removed from
1155 * @groups: NULL terminated list of groups to be removed
1157 * If groups is not NULL, remove the specified groups from the device.
1159 void devm_device_remove_groups(struct device
*dev
,
1160 const struct attribute_group
**groups
)
1162 WARN_ON(devres_release(dev
, devm_attr_groups_remove
,
1163 devm_attr_group_match
,
1164 /* cast away const */ (void *)groups
));
1166 EXPORT_SYMBOL_GPL(devm_device_remove_groups
);
1168 static int device_add_attrs(struct device
*dev
)
1170 struct class *class = dev
->class;
1171 const struct device_type
*type
= dev
->type
;
1175 error
= device_add_groups(dev
, class->dev_groups
);
1181 error
= device_add_groups(dev
, type
->groups
);
1183 goto err_remove_class_groups
;
1186 error
= device_add_groups(dev
, dev
->groups
);
1188 goto err_remove_type_groups
;
1190 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
1191 error
= device_create_file(dev
, &dev_attr_online
);
1193 goto err_remove_dev_groups
;
1198 err_remove_dev_groups
:
1199 device_remove_groups(dev
, dev
->groups
);
1200 err_remove_type_groups
:
1202 device_remove_groups(dev
, type
->groups
);
1203 err_remove_class_groups
:
1205 device_remove_groups(dev
, class->dev_groups
);
1210 static void device_remove_attrs(struct device
*dev
)
1212 struct class *class = dev
->class;
1213 const struct device_type
*type
= dev
->type
;
1215 device_remove_file(dev
, &dev_attr_online
);
1216 device_remove_groups(dev
, dev
->groups
);
1219 device_remove_groups(dev
, type
->groups
);
1222 device_remove_groups(dev
, class->dev_groups
);
1225 static ssize_t
dev_show(struct device
*dev
, struct device_attribute
*attr
,
1228 return print_dev_t(buf
, dev
->devt
);
1230 static DEVICE_ATTR_RO(dev
);
1233 struct kset
*devices_kset
;
1236 * devices_kset_move_before - Move device in the devices_kset's list.
1237 * @deva: Device to move.
1238 * @devb: Device @deva should come before.
1240 static void devices_kset_move_before(struct device
*deva
, struct device
*devb
)
1244 pr_debug("devices_kset: Moving %s before %s\n",
1245 dev_name(deva
), dev_name(devb
));
1246 spin_lock(&devices_kset
->list_lock
);
1247 list_move_tail(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1248 spin_unlock(&devices_kset
->list_lock
);
1252 * devices_kset_move_after - Move device in the devices_kset's list.
1253 * @deva: Device to move
1254 * @devb: Device @deva should come after.
1256 static void devices_kset_move_after(struct device
*deva
, struct device
*devb
)
1260 pr_debug("devices_kset: Moving %s after %s\n",
1261 dev_name(deva
), dev_name(devb
));
1262 spin_lock(&devices_kset
->list_lock
);
1263 list_move(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1264 spin_unlock(&devices_kset
->list_lock
);
1268 * devices_kset_move_last - move the device to the end of devices_kset's list.
1269 * @dev: device to move
1271 void devices_kset_move_last(struct device
*dev
)
1275 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev
));
1276 spin_lock(&devices_kset
->list_lock
);
1277 list_move_tail(&dev
->kobj
.entry
, &devices_kset
->list
);
1278 spin_unlock(&devices_kset
->list_lock
);
1282 * device_create_file - create sysfs attribute file for device.
1284 * @attr: device attribute descriptor.
1286 int device_create_file(struct device
*dev
,
1287 const struct device_attribute
*attr
)
1292 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
1293 "Attribute %s: write permission without 'store'\n",
1295 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
1296 "Attribute %s: read permission without 'show'\n",
1298 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
1303 EXPORT_SYMBOL_GPL(device_create_file
);
1306 * device_remove_file - remove sysfs attribute file.
1308 * @attr: device attribute descriptor.
1310 void device_remove_file(struct device
*dev
,
1311 const struct device_attribute
*attr
)
1314 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
1316 EXPORT_SYMBOL_GPL(device_remove_file
);
1319 * device_remove_file_self - remove sysfs attribute file from its own method.
1321 * @attr: device attribute descriptor.
1323 * See kernfs_remove_self() for details.
1325 bool device_remove_file_self(struct device
*dev
,
1326 const struct device_attribute
*attr
)
1329 return sysfs_remove_file_self(&dev
->kobj
, &attr
->attr
);
1333 EXPORT_SYMBOL_GPL(device_remove_file_self
);
1336 * device_create_bin_file - create sysfs binary attribute file for device.
1338 * @attr: device binary attribute descriptor.
1340 int device_create_bin_file(struct device
*dev
,
1341 const struct bin_attribute
*attr
)
1343 int error
= -EINVAL
;
1345 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
1348 EXPORT_SYMBOL_GPL(device_create_bin_file
);
1351 * device_remove_bin_file - remove sysfs binary attribute file
1353 * @attr: device binary attribute descriptor.
1355 void device_remove_bin_file(struct device
*dev
,
1356 const struct bin_attribute
*attr
)
1359 sysfs_remove_bin_file(&dev
->kobj
, attr
);
1361 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
1363 static void klist_children_get(struct klist_node
*n
)
1365 struct device_private
*p
= to_device_private_parent(n
);
1366 struct device
*dev
= p
->device
;
1371 static void klist_children_put(struct klist_node
*n
)
1373 struct device_private
*p
= to_device_private_parent(n
);
1374 struct device
*dev
= p
->device
;
1380 * device_initialize - init device structure.
1383 * This prepares the device for use by other layers by initializing
1385 * It is the first half of device_register(), if called by
1386 * that function, though it can also be called separately, so one
1387 * may use @dev's fields. In particular, get_device()/put_device()
1388 * may be used for reference counting of @dev after calling this
1391 * All fields in @dev must be initialized by the caller to 0, except
1392 * for those explicitly set to some other value. The simplest
1393 * approach is to use kzalloc() to allocate the structure containing
1396 * NOTE: Use put_device() to give up your reference instead of freeing
1397 * @dev directly once you have called this function.
1399 void device_initialize(struct device
*dev
)
1401 dev
->kobj
.kset
= devices_kset
;
1402 kobject_init(&dev
->kobj
, &device_ktype
);
1403 INIT_LIST_HEAD(&dev
->dma_pools
);
1404 mutex_init(&dev
->mutex
);
1405 lockdep_set_novalidate_class(&dev
->mutex
);
1406 spin_lock_init(&dev
->devres_lock
);
1407 INIT_LIST_HEAD(&dev
->devres_head
);
1408 device_pm_init(dev
);
1409 set_dev_node(dev
, -1);
1410 #ifdef CONFIG_GENERIC_MSI_IRQ
1411 INIT_LIST_HEAD(&dev
->msi_list
);
1413 INIT_LIST_HEAD(&dev
->links
.consumers
);
1414 INIT_LIST_HEAD(&dev
->links
.suppliers
);
1415 dev
->links
.status
= DL_DEV_NO_DRIVER
;
1417 EXPORT_SYMBOL_GPL(device_initialize
);
1419 struct kobject
*virtual_device_parent(struct device
*dev
)
1421 static struct kobject
*virtual_dir
= NULL
;
1424 virtual_dir
= kobject_create_and_add("virtual",
1425 &devices_kset
->kobj
);
1431 struct kobject kobj
;
1432 struct class *class;
1435 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1437 static void class_dir_release(struct kobject
*kobj
)
1439 struct class_dir
*dir
= to_class_dir(kobj
);
1444 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
1446 struct class_dir
*dir
= to_class_dir(kobj
);
1447 return dir
->class->ns_type
;
1450 static struct kobj_type class_dir_ktype
= {
1451 .release
= class_dir_release
,
1452 .sysfs_ops
= &kobj_sysfs_ops
,
1453 .child_ns_type
= class_dir_child_ns_type
1456 static struct kobject
*
1457 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
1459 struct class_dir
*dir
;
1462 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1467 kobject_init(&dir
->kobj
, &class_dir_ktype
);
1469 dir
->kobj
.kset
= &class->p
->glue_dirs
;
1471 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
1473 kobject_put(&dir
->kobj
);
1479 static DEFINE_MUTEX(gdp_mutex
);
1481 static struct kobject
*get_device_parent(struct device
*dev
,
1482 struct device
*parent
)
1485 struct kobject
*kobj
= NULL
;
1486 struct kobject
*parent_kobj
;
1490 /* block disks show up in /sys/block */
1491 if (sysfs_deprecated
&& dev
->class == &block_class
) {
1492 if (parent
&& parent
->class == &block_class
)
1493 return &parent
->kobj
;
1494 return &block_class
.p
->subsys
.kobj
;
1499 * If we have no parent, we live in "virtual".
1500 * Class-devices with a non class-device as parent, live
1501 * in a "glue" directory to prevent namespace collisions.
1504 parent_kobj
= virtual_device_parent(dev
);
1505 else if (parent
->class && !dev
->class->ns_type
)
1506 return &parent
->kobj
;
1508 parent_kobj
= &parent
->kobj
;
1510 mutex_lock(&gdp_mutex
);
1512 /* find our class-directory at the parent and reference it */
1513 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
1514 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
1515 if (k
->parent
== parent_kobj
) {
1516 kobj
= kobject_get(k
);
1519 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
1521 mutex_unlock(&gdp_mutex
);
1525 /* or create a new class-directory at the parent device */
1526 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
1527 /* do not emit an uevent for this simple "glue" directory */
1528 mutex_unlock(&gdp_mutex
);
1532 /* subsystems can specify a default root directory for their devices */
1533 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
1534 return &dev
->bus
->dev_root
->kobj
;
1537 return &parent
->kobj
;
1541 static inline bool live_in_glue_dir(struct kobject
*kobj
,
1544 if (!kobj
|| !dev
->class ||
1545 kobj
->kset
!= &dev
->class->p
->glue_dirs
)
1550 static inline struct kobject
*get_glue_dir(struct device
*dev
)
1552 return dev
->kobj
.parent
;
1556 * make sure cleaning up dir as the last step, we need to make
1557 * sure .release handler of kobject is run with holding the
1560 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
1562 /* see if we live in a "glue" directory */
1563 if (!live_in_glue_dir(glue_dir
, dev
))
1566 mutex_lock(&gdp_mutex
);
1567 kobject_put(glue_dir
);
1568 mutex_unlock(&gdp_mutex
);
1571 static int device_add_class_symlinks(struct device
*dev
)
1573 struct device_node
*of_node
= dev_of_node(dev
);
1577 error
= sysfs_create_link(&dev
->kobj
, &of_node
->kobj
,"of_node");
1579 dev_warn(dev
, "Error %d creating of_node link\n",error
);
1580 /* An error here doesn't warrant bringing down the device */
1586 error
= sysfs_create_link(&dev
->kobj
,
1587 &dev
->class->p
->subsys
.kobj
,
1592 if (dev
->parent
&& device_is_not_partition(dev
)) {
1593 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
1600 /* /sys/block has directories and does not need symlinks */
1601 if (sysfs_deprecated
&& dev
->class == &block_class
)
1605 /* link in the class directory pointing to the device */
1606 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
1607 &dev
->kobj
, dev_name(dev
));
1614 sysfs_remove_link(&dev
->kobj
, "device");
1617 sysfs_remove_link(&dev
->kobj
, "subsystem");
1619 sysfs_remove_link(&dev
->kobj
, "of_node");
1623 static void device_remove_class_symlinks(struct device
*dev
)
1625 if (dev_of_node(dev
))
1626 sysfs_remove_link(&dev
->kobj
, "of_node");
1631 if (dev
->parent
&& device_is_not_partition(dev
))
1632 sysfs_remove_link(&dev
->kobj
, "device");
1633 sysfs_remove_link(&dev
->kobj
, "subsystem");
1635 if (sysfs_deprecated
&& dev
->class == &block_class
)
1638 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
1642 * dev_set_name - set a device name
1644 * @fmt: format string for the device's name
1646 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
1651 va_start(vargs
, fmt
);
1652 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
1656 EXPORT_SYMBOL_GPL(dev_set_name
);
1659 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1662 * By default we select char/ for new entries. Setting class->dev_obj
1663 * to NULL prevents an entry from being created. class->dev_kobj must
1664 * be set (or cleared) before any devices are registered to the class
1665 * otherwise device_create_sys_dev_entry() and
1666 * device_remove_sys_dev_entry() will disagree about the presence of
1669 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
1671 struct kobject
*kobj
;
1674 kobj
= dev
->class->dev_kobj
;
1676 kobj
= sysfs_dev_char_kobj
;
1681 static int device_create_sys_dev_entry(struct device
*dev
)
1683 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1688 format_dev_t(devt_str
, dev
->devt
);
1689 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
1695 static void device_remove_sys_dev_entry(struct device
*dev
)
1697 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1701 format_dev_t(devt_str
, dev
->devt
);
1702 sysfs_remove_link(kobj
, devt_str
);
1706 int device_private_init(struct device
*dev
)
1708 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1711 dev
->p
->device
= dev
;
1712 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1713 klist_children_put
);
1714 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1719 * device_add - add device to device hierarchy.
1722 * This is part 2 of device_register(), though may be called
1723 * separately _iff_ device_initialize() has been called separately.
1725 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1726 * to the global and sibling lists for the device, then
1727 * adds it to the other relevant subsystems of the driver model.
1729 * Do not call this routine or device_register() more than once for
1730 * any device structure. The driver model core is not designed to work
1731 * with devices that get unregistered and then spring back to life.
1732 * (Among other things, it's very hard to guarantee that all references
1733 * to the previous incarnation of @dev have been dropped.) Allocate
1734 * and register a fresh new struct device instead.
1736 * NOTE: _Never_ directly free @dev after calling this function, even
1737 * if it returned an error! Always use put_device() to give up your
1738 * reference instead.
1740 int device_add(struct device
*dev
)
1742 struct device
*parent
;
1743 struct kobject
*kobj
;
1744 struct class_interface
*class_intf
;
1745 int error
= -EINVAL
;
1746 struct kobject
*glue_dir
= NULL
;
1748 dev
= get_device(dev
);
1753 error
= device_private_init(dev
);
1759 * for statically allocated devices, which should all be converted
1760 * some day, we need to initialize the name. We prevent reading back
1761 * the name, and force the use of dev_name()
1763 if (dev
->init_name
) {
1764 dev_set_name(dev
, "%s", dev
->init_name
);
1765 dev
->init_name
= NULL
;
1768 /* subsystems can specify simple device enumeration */
1769 if (!dev_name(dev
) && dev
->bus
&& dev
->bus
->dev_name
)
1770 dev_set_name(dev
, "%s%u", dev
->bus
->dev_name
, dev
->id
);
1772 if (!dev_name(dev
)) {
1777 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1779 parent
= get_device(dev
->parent
);
1780 kobj
= get_device_parent(dev
, parent
);
1782 dev
->kobj
.parent
= kobj
;
1784 /* use parent numa_node */
1785 if (parent
&& (dev_to_node(dev
) == NUMA_NO_NODE
))
1786 set_dev_node(dev
, dev_to_node(parent
));
1788 /* first, register with generic layer. */
1789 /* we require the name to be set before, and pass NULL */
1790 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
1792 glue_dir
= get_glue_dir(dev
);
1796 /* notify platform of device entry */
1797 if (platform_notify
)
1798 platform_notify(dev
);
1800 error
= device_create_file(dev
, &dev_attr_uevent
);
1804 error
= device_add_class_symlinks(dev
);
1807 error
= device_add_attrs(dev
);
1810 error
= bus_add_device(dev
);
1813 error
= dpm_sysfs_add(dev
);
1818 if (MAJOR(dev
->devt
)) {
1819 error
= device_create_file(dev
, &dev_attr_dev
);
1823 error
= device_create_sys_dev_entry(dev
);
1827 devtmpfs_create_node(dev
);
1830 /* Notify clients of device addition. This call must come
1831 * after dpm_sysfs_add() and before kobject_uevent().
1834 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1835 BUS_NOTIFY_ADD_DEVICE
, dev
);
1837 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1838 bus_probe_device(dev
);
1840 klist_add_tail(&dev
->p
->knode_parent
,
1841 &parent
->p
->klist_children
);
1844 mutex_lock(&dev
->class->p
->mutex
);
1845 /* tie the class to the device */
1846 klist_add_tail(&dev
->knode_class
,
1847 &dev
->class->p
->klist_devices
);
1849 /* notify any interfaces that the device is here */
1850 list_for_each_entry(class_intf
,
1851 &dev
->class->p
->interfaces
, node
)
1852 if (class_intf
->add_dev
)
1853 class_intf
->add_dev(dev
, class_intf
);
1854 mutex_unlock(&dev
->class->p
->mutex
);
1860 if (MAJOR(dev
->devt
))
1861 device_remove_file(dev
, &dev_attr_dev
);
1863 device_pm_remove(dev
);
1864 dpm_sysfs_remove(dev
);
1866 bus_remove_device(dev
);
1868 device_remove_attrs(dev
);
1870 device_remove_class_symlinks(dev
);
1872 device_remove_file(dev
, &dev_attr_uevent
);
1874 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1875 glue_dir
= get_glue_dir(dev
);
1876 kobject_del(&dev
->kobj
);
1878 cleanup_glue_dir(dev
, glue_dir
);
1885 EXPORT_SYMBOL_GPL(device_add
);
1888 * device_register - register a device with the system.
1889 * @dev: pointer to the device structure
1891 * This happens in two clean steps - initialize the device
1892 * and add it to the system. The two steps can be called
1893 * separately, but this is the easiest and most common.
1894 * I.e. you should only call the two helpers separately if
1895 * have a clearly defined need to use and refcount the device
1896 * before it is added to the hierarchy.
1898 * For more information, see the kerneldoc for device_initialize()
1901 * NOTE: _Never_ directly free @dev after calling this function, even
1902 * if it returned an error! Always use put_device() to give up the
1903 * reference initialized in this function instead.
1905 int device_register(struct device
*dev
)
1907 device_initialize(dev
);
1908 return device_add(dev
);
1910 EXPORT_SYMBOL_GPL(device_register
);
1913 * get_device - increment reference count for device.
1916 * This simply forwards the call to kobject_get(), though
1917 * we do take care to provide for the case that we get a NULL
1918 * pointer passed in.
1920 struct device
*get_device(struct device
*dev
)
1922 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1924 EXPORT_SYMBOL_GPL(get_device
);
1927 * put_device - decrement reference count.
1928 * @dev: device in question.
1930 void put_device(struct device
*dev
)
1932 /* might_sleep(); */
1934 kobject_put(&dev
->kobj
);
1936 EXPORT_SYMBOL_GPL(put_device
);
1939 * device_del - delete device from system.
1942 * This is the first part of the device unregistration
1943 * sequence. This removes the device from the lists we control
1944 * from here, has it removed from the other driver model
1945 * subsystems it was added to in device_add(), and removes it
1946 * from the kobject hierarchy.
1948 * NOTE: this should be called manually _iff_ device_add() was
1949 * also called manually.
1951 void device_del(struct device
*dev
)
1953 struct device
*parent
= dev
->parent
;
1954 struct kobject
*glue_dir
= NULL
;
1955 struct class_interface
*class_intf
;
1957 /* Notify clients of device removal. This call must come
1958 * before dpm_sysfs_remove().
1961 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1962 BUS_NOTIFY_DEL_DEVICE
, dev
);
1964 device_links_purge(dev
);
1965 dpm_sysfs_remove(dev
);
1967 klist_del(&dev
->p
->knode_parent
);
1968 if (MAJOR(dev
->devt
)) {
1969 devtmpfs_delete_node(dev
);
1970 device_remove_sys_dev_entry(dev
);
1971 device_remove_file(dev
, &dev_attr_dev
);
1974 device_remove_class_symlinks(dev
);
1976 mutex_lock(&dev
->class->p
->mutex
);
1977 /* notify any interfaces that the device is now gone */
1978 list_for_each_entry(class_intf
,
1979 &dev
->class->p
->interfaces
, node
)
1980 if (class_intf
->remove_dev
)
1981 class_intf
->remove_dev(dev
, class_intf
);
1982 /* remove the device from the class list */
1983 klist_del(&dev
->knode_class
);
1984 mutex_unlock(&dev
->class->p
->mutex
);
1986 device_remove_file(dev
, &dev_attr_uevent
);
1987 device_remove_attrs(dev
);
1988 bus_remove_device(dev
);
1989 device_pm_remove(dev
);
1990 driver_deferred_probe_del(dev
);
1991 device_remove_properties(dev
);
1993 /* Notify the platform of the removal, in case they
1994 * need to do anything...
1996 if (platform_notify_remove
)
1997 platform_notify_remove(dev
);
1999 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
2000 BUS_NOTIFY_REMOVED_DEVICE
, dev
);
2001 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
2002 glue_dir
= get_glue_dir(dev
);
2003 kobject_del(&dev
->kobj
);
2004 cleanup_glue_dir(dev
, glue_dir
);
2007 EXPORT_SYMBOL_GPL(device_del
);
2010 * device_unregister - unregister device from system.
2011 * @dev: device going away.
2013 * We do this in two parts, like we do device_register(). First,
2014 * we remove it from all the subsystems with device_del(), then
2015 * we decrement the reference count via put_device(). If that
2016 * is the final reference count, the device will be cleaned up
2017 * via device_release() above. Otherwise, the structure will
2018 * stick around until the final reference to the device is dropped.
2020 void device_unregister(struct device
*dev
)
2022 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
2026 EXPORT_SYMBOL_GPL(device_unregister
);
2028 static struct device
*prev_device(struct klist_iter
*i
)
2030 struct klist_node
*n
= klist_prev(i
);
2031 struct device
*dev
= NULL
;
2032 struct device_private
*p
;
2035 p
= to_device_private_parent(n
);
2041 static struct device
*next_device(struct klist_iter
*i
)
2043 struct klist_node
*n
= klist_next(i
);
2044 struct device
*dev
= NULL
;
2045 struct device_private
*p
;
2048 p
= to_device_private_parent(n
);
2055 * device_get_devnode - path of device node file
2057 * @mode: returned file access mode
2058 * @uid: returned file owner
2059 * @gid: returned file group
2060 * @tmp: possibly allocated string
2062 * Return the relative path of a possible device node.
2063 * Non-default names may need to allocate a memory to compose
2064 * a name. This memory is returned in tmp and needs to be
2065 * freed by the caller.
2067 const char *device_get_devnode(struct device
*dev
,
2068 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
2075 /* the device type may provide a specific name */
2076 if (dev
->type
&& dev
->type
->devnode
)
2077 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
2081 /* the class may provide a specific name */
2082 if (dev
->class && dev
->class->devnode
)
2083 *tmp
= dev
->class->devnode(dev
, mode
);
2087 /* return name without allocation, tmp == NULL */
2088 if (strchr(dev_name(dev
), '!') == NULL
)
2089 return dev_name(dev
);
2091 /* replace '!' in the name with '/' */
2092 s
= kstrdup(dev_name(dev
), GFP_KERNEL
);
2095 strreplace(s
, '!', '/');
2100 * device_for_each_child - device child iterator.
2101 * @parent: parent struct device.
2102 * @fn: function to be called for each device.
2103 * @data: data for the callback.
2105 * Iterate over @parent's child devices, and call @fn for each,
2108 * We check the return of @fn each time. If it returns anything
2109 * other than 0, we break out and return that value.
2111 int device_for_each_child(struct device
*parent
, void *data
,
2112 int (*fn
)(struct device
*dev
, void *data
))
2114 struct klist_iter i
;
2115 struct device
*child
;
2121 klist_iter_init(&parent
->p
->klist_children
, &i
);
2122 while ((child
= next_device(&i
)) && !error
)
2123 error
= fn(child
, data
);
2124 klist_iter_exit(&i
);
2127 EXPORT_SYMBOL_GPL(device_for_each_child
);
2130 * device_for_each_child_reverse - device child iterator in reversed order.
2131 * @parent: parent struct device.
2132 * @fn: function to be called for each device.
2133 * @data: data for the callback.
2135 * Iterate over @parent's child devices, and call @fn for each,
2138 * We check the return of @fn each time. If it returns anything
2139 * other than 0, we break out and return that value.
2141 int device_for_each_child_reverse(struct device
*parent
, void *data
,
2142 int (*fn
)(struct device
*dev
, void *data
))
2144 struct klist_iter i
;
2145 struct device
*child
;
2151 klist_iter_init(&parent
->p
->klist_children
, &i
);
2152 while ((child
= prev_device(&i
)) && !error
)
2153 error
= fn(child
, data
);
2154 klist_iter_exit(&i
);
2157 EXPORT_SYMBOL_GPL(device_for_each_child_reverse
);
2160 * device_find_child - device iterator for locating a particular device.
2161 * @parent: parent struct device
2162 * @match: Callback function to check device
2163 * @data: Data to pass to match function
2165 * This is similar to the device_for_each_child() function above, but it
2166 * returns a reference to a device that is 'found' for later use, as
2167 * determined by the @match callback.
2169 * The callback should return 0 if the device doesn't match and non-zero
2170 * if it does. If the callback returns non-zero and a reference to the
2171 * current device can be obtained, this function will return to the caller
2172 * and not iterate over any more devices.
2174 * NOTE: you will need to drop the reference with put_device() after use.
2176 struct device
*device_find_child(struct device
*parent
, void *data
,
2177 int (*match
)(struct device
*dev
, void *data
))
2179 struct klist_iter i
;
2180 struct device
*child
;
2185 klist_iter_init(&parent
->p
->klist_children
, &i
);
2186 while ((child
= next_device(&i
)))
2187 if (match(child
, data
) && get_device(child
))
2189 klist_iter_exit(&i
);
2192 EXPORT_SYMBOL_GPL(device_find_child
);
2194 int __init
devices_init(void)
2196 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
2199 dev_kobj
= kobject_create_and_add("dev", NULL
);
2202 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
2203 if (!sysfs_dev_block_kobj
)
2204 goto block_kobj_err
;
2205 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
2206 if (!sysfs_dev_char_kobj
)
2212 kobject_put(sysfs_dev_block_kobj
);
2214 kobject_put(dev_kobj
);
2216 kset_unregister(devices_kset
);
2220 static int device_check_offline(struct device
*dev
, void *not_used
)
2224 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2228 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
2232 * device_offline - Prepare the device for hot-removal.
2233 * @dev: Device to be put offline.
2235 * Execute the device bus type's .offline() callback, if present, to prepare
2236 * the device for a subsequent hot-removal. If that succeeds, the device must
2237 * not be used until either it is removed or its bus type's .online() callback
2240 * Call under device_hotplug_lock.
2242 int device_offline(struct device
*dev
)
2246 if (dev
->offline_disabled
)
2249 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2254 if (device_supports_offline(dev
)) {
2258 ret
= dev
->bus
->offline(dev
);
2260 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
2261 dev
->offline
= true;
2271 * device_online - Put the device back online after successful device_offline().
2272 * @dev: Device to be put back online.
2274 * If device_offline() has been successfully executed for @dev, but the device
2275 * has not been removed subsequently, execute its bus type's .online() callback
2276 * to indicate that the device can be used again.
2278 * Call under device_hotplug_lock.
2280 int device_online(struct device
*dev
)
2285 if (device_supports_offline(dev
)) {
2287 ret
= dev
->bus
->online(dev
);
2289 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
2290 dev
->offline
= false;
2301 struct root_device
{
2303 struct module
*owner
;
2306 static inline struct root_device
*to_root_device(struct device
*d
)
2308 return container_of(d
, struct root_device
, dev
);
2311 static void root_device_release(struct device
*dev
)
2313 kfree(to_root_device(dev
));
2317 * __root_device_register - allocate and register a root device
2318 * @name: root device name
2319 * @owner: owner module of the root device, usually THIS_MODULE
2321 * This function allocates a root device and registers it
2322 * using device_register(). In order to free the returned
2323 * device, use root_device_unregister().
2325 * Root devices are dummy devices which allow other devices
2326 * to be grouped under /sys/devices. Use this function to
2327 * allocate a root device and then use it as the parent of
2328 * any device which should appear under /sys/devices/{name}
2330 * The /sys/devices/{name} directory will also contain a
2331 * 'module' symlink which points to the @owner directory
2334 * Returns &struct device pointer on success, or ERR_PTR() on error.
2336 * Note: You probably want to use root_device_register().
2338 struct device
*__root_device_register(const char *name
, struct module
*owner
)
2340 struct root_device
*root
;
2343 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
2345 return ERR_PTR(err
);
2347 err
= dev_set_name(&root
->dev
, "%s", name
);
2350 return ERR_PTR(err
);
2353 root
->dev
.release
= root_device_release
;
2355 err
= device_register(&root
->dev
);
2357 put_device(&root
->dev
);
2358 return ERR_PTR(err
);
2361 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2363 struct module_kobject
*mk
= &owner
->mkobj
;
2365 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
2367 device_unregister(&root
->dev
);
2368 return ERR_PTR(err
);
2370 root
->owner
= owner
;
2376 EXPORT_SYMBOL_GPL(__root_device_register
);
2379 * root_device_unregister - unregister and free a root device
2380 * @dev: device going away
2382 * This function unregisters and cleans up a device that was created by
2383 * root_device_register().
2385 void root_device_unregister(struct device
*dev
)
2387 struct root_device
*root
= to_root_device(dev
);
2390 sysfs_remove_link(&root
->dev
.kobj
, "module");
2392 device_unregister(dev
);
2394 EXPORT_SYMBOL_GPL(root_device_unregister
);
2397 static void device_create_release(struct device
*dev
)
2399 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
2403 static struct device
*
2404 device_create_groups_vargs(struct class *class, struct device
*parent
,
2405 dev_t devt
, void *drvdata
,
2406 const struct attribute_group
**groups
,
2407 const char *fmt
, va_list args
)
2409 struct device
*dev
= NULL
;
2410 int retval
= -ENODEV
;
2412 if (class == NULL
|| IS_ERR(class))
2415 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
2421 device_initialize(dev
);
2424 dev
->parent
= parent
;
2425 dev
->groups
= groups
;
2426 dev
->release
= device_create_release
;
2427 dev_set_drvdata(dev
, drvdata
);
2429 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
2433 retval
= device_add(dev
);
2441 return ERR_PTR(retval
);
2445 * device_create_vargs - creates a device and registers it with sysfs
2446 * @class: pointer to the struct class that this device should be registered to
2447 * @parent: pointer to the parent struct device of this new device, if any
2448 * @devt: the dev_t for the char device to be added
2449 * @drvdata: the data to be added to the device for callbacks
2450 * @fmt: string for the device's name
2451 * @args: va_list for the device's name
2453 * This function can be used by char device classes. A struct device
2454 * will be created in sysfs, registered to the specified class.
2456 * A "dev" file will be created, showing the dev_t for the device, if
2457 * the dev_t is not 0,0.
2458 * If a pointer to a parent struct device is passed in, the newly created
2459 * struct device will be a child of that device in sysfs.
2460 * The pointer to the struct device will be returned from the call.
2461 * Any further sysfs files that might be required can be created using this
2464 * Returns &struct device pointer on success, or ERR_PTR() on error.
2466 * Note: the struct class passed to this function must have previously
2467 * been created with a call to class_create().
2469 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
2470 dev_t devt
, void *drvdata
, const char *fmt
,
2473 return device_create_groups_vargs(class, parent
, devt
, drvdata
, NULL
,
2476 EXPORT_SYMBOL_GPL(device_create_vargs
);
2479 * device_create - creates a device and registers it with sysfs
2480 * @class: pointer to the struct class that this device should be registered to
2481 * @parent: pointer to the parent struct device of this new device, if any
2482 * @devt: the dev_t for the char device to be added
2483 * @drvdata: the data to be added to the device for callbacks
2484 * @fmt: string for the device's name
2486 * This function can be used by char device classes. A struct device
2487 * will be created in sysfs, registered to the specified class.
2489 * A "dev" file will be created, showing the dev_t for the device, if
2490 * the dev_t is not 0,0.
2491 * If a pointer to a parent struct device is passed in, the newly created
2492 * struct device will be a child of that device in sysfs.
2493 * The pointer to the struct device will be returned from the call.
2494 * Any further sysfs files that might be required can be created using this
2497 * Returns &struct device pointer on success, or ERR_PTR() on error.
2499 * Note: the struct class passed to this function must have previously
2500 * been created with a call to class_create().
2502 struct device
*device_create(struct class *class, struct device
*parent
,
2503 dev_t devt
, void *drvdata
, const char *fmt
, ...)
2508 va_start(vargs
, fmt
);
2509 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
2513 EXPORT_SYMBOL_GPL(device_create
);
2516 * device_create_with_groups - creates a device and registers it with sysfs
2517 * @class: pointer to the struct class that this device should be registered to
2518 * @parent: pointer to the parent struct device of this new device, if any
2519 * @devt: the dev_t for the char device to be added
2520 * @drvdata: the data to be added to the device for callbacks
2521 * @groups: NULL-terminated list of attribute groups to be created
2522 * @fmt: string for the device's name
2524 * This function can be used by char device classes. A struct device
2525 * will be created in sysfs, registered to the specified class.
2526 * Additional attributes specified in the groups parameter will also
2527 * be created automatically.
2529 * A "dev" file will be created, showing the dev_t for the device, if
2530 * the dev_t is not 0,0.
2531 * If a pointer to a parent struct device is passed in, the newly created
2532 * struct device will be a child of that device in sysfs.
2533 * The pointer to the struct device will be returned from the call.
2534 * Any further sysfs files that might be required can be created using this
2537 * Returns &struct device pointer on success, or ERR_PTR() on error.
2539 * Note: the struct class passed to this function must have previously
2540 * been created with a call to class_create().
2542 struct device
*device_create_with_groups(struct class *class,
2543 struct device
*parent
, dev_t devt
,
2545 const struct attribute_group
**groups
,
2546 const char *fmt
, ...)
2551 va_start(vargs
, fmt
);
2552 dev
= device_create_groups_vargs(class, parent
, devt
, drvdata
, groups
,
2557 EXPORT_SYMBOL_GPL(device_create_with_groups
);
2559 static int __match_devt(struct device
*dev
, const void *data
)
2561 const dev_t
*devt
= data
;
2563 return dev
->devt
== *devt
;
2567 * device_destroy - removes a device that was created with device_create()
2568 * @class: pointer to the struct class that this device was registered with
2569 * @devt: the dev_t of the device that was previously registered
2571 * This call unregisters and cleans up a device that was created with a
2572 * call to device_create().
2574 void device_destroy(struct class *class, dev_t devt
)
2578 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
2581 device_unregister(dev
);
2584 EXPORT_SYMBOL_GPL(device_destroy
);
2587 * device_rename - renames a device
2588 * @dev: the pointer to the struct device to be renamed
2589 * @new_name: the new name of the device
2591 * It is the responsibility of the caller to provide mutual
2592 * exclusion between two different calls of device_rename
2593 * on the same device to ensure that new_name is valid and
2594 * won't conflict with other devices.
2596 * Note: Don't call this function. Currently, the networking layer calls this
2597 * function, but that will change. The following text from Kay Sievers offers
2600 * Renaming devices is racy at many levels, symlinks and other stuff are not
2601 * replaced atomically, and you get a "move" uevent, but it's not easy to
2602 * connect the event to the old and new device. Device nodes are not renamed at
2603 * all, there isn't even support for that in the kernel now.
2605 * In the meantime, during renaming, your target name might be taken by another
2606 * driver, creating conflicts. Or the old name is taken directly after you
2607 * renamed it -- then you get events for the same DEVPATH, before you even see
2608 * the "move" event. It's just a mess, and nothing new should ever rely on
2609 * kernel device renaming. Besides that, it's not even implemented now for
2610 * other things than (driver-core wise very simple) network devices.
2612 * We are currently about to change network renaming in udev to completely
2613 * disallow renaming of devices in the same namespace as the kernel uses,
2614 * because we can't solve the problems properly, that arise with swapping names
2615 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2616 * be allowed to some other name than eth[0-9]*, for the aforementioned
2619 * Make up a "real" name in the driver before you register anything, or add
2620 * some other attributes for userspace to find the device, or use udev to add
2621 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2622 * don't even want to get into that and try to implement the missing pieces in
2623 * the core. We really have other pieces to fix in the driver core mess. :)
2625 int device_rename(struct device
*dev
, const char *new_name
)
2627 struct kobject
*kobj
= &dev
->kobj
;
2628 char *old_device_name
= NULL
;
2631 dev
= get_device(dev
);
2635 dev_dbg(dev
, "renaming to %s\n", new_name
);
2637 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
2638 if (!old_device_name
) {
2644 error
= sysfs_rename_link_ns(&dev
->class->p
->subsys
.kobj
,
2645 kobj
, old_device_name
,
2646 new_name
, kobject_namespace(kobj
));
2651 error
= kobject_rename(kobj
, new_name
);
2658 kfree(old_device_name
);
2662 EXPORT_SYMBOL_GPL(device_rename
);
2664 static int device_move_class_links(struct device
*dev
,
2665 struct device
*old_parent
,
2666 struct device
*new_parent
)
2671 sysfs_remove_link(&dev
->kobj
, "device");
2673 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
2679 * device_move - moves a device to a new parent
2680 * @dev: the pointer to the struct device to be moved
2681 * @new_parent: the new parent of the device (can by NULL)
2682 * @dpm_order: how to reorder the dpm_list
2684 int device_move(struct device
*dev
, struct device
*new_parent
,
2685 enum dpm_order dpm_order
)
2688 struct device
*old_parent
;
2689 struct kobject
*new_parent_kobj
;
2691 dev
= get_device(dev
);
2696 new_parent
= get_device(new_parent
);
2697 new_parent_kobj
= get_device_parent(dev
, new_parent
);
2699 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
2700 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
2701 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
2703 cleanup_glue_dir(dev
, new_parent_kobj
);
2704 put_device(new_parent
);
2707 old_parent
= dev
->parent
;
2708 dev
->parent
= new_parent
;
2710 klist_remove(&dev
->p
->knode_parent
);
2712 klist_add_tail(&dev
->p
->knode_parent
,
2713 &new_parent
->p
->klist_children
);
2714 set_dev_node(dev
, dev_to_node(new_parent
));
2718 error
= device_move_class_links(dev
, old_parent
, new_parent
);
2720 /* We ignore errors on cleanup since we're hosed anyway... */
2721 device_move_class_links(dev
, new_parent
, old_parent
);
2722 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
2724 klist_remove(&dev
->p
->knode_parent
);
2725 dev
->parent
= old_parent
;
2727 klist_add_tail(&dev
->p
->knode_parent
,
2728 &old_parent
->p
->klist_children
);
2729 set_dev_node(dev
, dev_to_node(old_parent
));
2732 cleanup_glue_dir(dev
, new_parent_kobj
);
2733 put_device(new_parent
);
2737 switch (dpm_order
) {
2738 case DPM_ORDER_NONE
:
2740 case DPM_ORDER_DEV_AFTER_PARENT
:
2741 device_pm_move_after(dev
, new_parent
);
2742 devices_kset_move_after(dev
, new_parent
);
2744 case DPM_ORDER_PARENT_BEFORE_DEV
:
2745 device_pm_move_before(new_parent
, dev
);
2746 devices_kset_move_before(new_parent
, dev
);
2748 case DPM_ORDER_DEV_LAST
:
2749 device_pm_move_last(dev
);
2750 devices_kset_move_last(dev
);
2754 put_device(old_parent
);
2760 EXPORT_SYMBOL_GPL(device_move
);
2763 * device_shutdown - call ->shutdown() on each device to shutdown.
2765 void device_shutdown(void)
2767 struct device
*dev
, *parent
;
2769 spin_lock(&devices_kset
->list_lock
);
2771 * Walk the devices list backward, shutting down each in turn.
2772 * Beware that device unplug events may also start pulling
2773 * devices offline, even as the system is shutting down.
2775 while (!list_empty(&devices_kset
->list
)) {
2776 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
2780 * hold reference count of device's parent to
2781 * prevent it from being freed because parent's
2782 * lock is to be held
2784 parent
= get_device(dev
->parent
);
2787 * Make sure the device is off the kset list, in the
2788 * event that dev->*->shutdown() doesn't remove it.
2790 list_del_init(&dev
->kobj
.entry
);
2791 spin_unlock(&devices_kset
->list_lock
);
2793 /* hold lock to avoid race with probe/release */
2795 device_lock(parent
);
2798 /* Don't allow any more runtime suspends */
2799 pm_runtime_get_noresume(dev
);
2800 pm_runtime_barrier(dev
);
2802 if (dev
->bus
&& dev
->bus
->shutdown
) {
2804 dev_info(dev
, "shutdown\n");
2805 dev
->bus
->shutdown(dev
);
2806 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2808 dev_info(dev
, "shutdown\n");
2809 dev
->driver
->shutdown(dev
);
2814 device_unlock(parent
);
2819 spin_lock(&devices_kset
->list_lock
);
2821 spin_unlock(&devices_kset
->list_lock
);
2825 * Device logging functions
2828 #ifdef CONFIG_PRINTK
2830 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2836 subsys
= dev
->class->name
;
2838 subsys
= dev
->bus
->name
;
2842 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2847 * Add device identifier DEVICE=:
2851 * +sound:card0 subsystem:devname
2853 if (MAJOR(dev
->devt
)) {
2856 if (strcmp(subsys
, "block") == 0)
2861 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2863 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2864 } else if (strcmp(subsys
, "net") == 0) {
2865 struct net_device
*net
= to_net_dev(dev
);
2868 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2869 "DEVICE=n%u", net
->ifindex
);
2872 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2873 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2882 dev_WARN(dev
, "device/subsystem name too long");
2886 int dev_vprintk_emit(int level
, const struct device
*dev
,
2887 const char *fmt
, va_list args
)
2892 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2894 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2896 EXPORT_SYMBOL(dev_vprintk_emit
);
2898 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2903 va_start(args
, fmt
);
2905 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2911 EXPORT_SYMBOL(dev_printk_emit
);
2913 static void __dev_printk(const char *level
, const struct device
*dev
,
2914 struct va_format
*vaf
)
2917 dev_printk_emit(level
[1] - '0', dev
, "%s %s: %pV",
2918 dev_driver_string(dev
), dev_name(dev
), vaf
);
2920 printk("%s(NULL device *): %pV", level
, vaf
);
2923 void dev_printk(const char *level
, const struct device
*dev
,
2924 const char *fmt
, ...)
2926 struct va_format vaf
;
2929 va_start(args
, fmt
);
2934 __dev_printk(level
, dev
, &vaf
);
2938 EXPORT_SYMBOL(dev_printk
);
2940 #define define_dev_printk_level(func, kern_level) \
2941 void func(const struct device *dev, const char *fmt, ...) \
2943 struct va_format vaf; \
2946 va_start(args, fmt); \
2951 __dev_printk(kern_level, dev, &vaf); \
2955 EXPORT_SYMBOL(func);
2957 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
2958 define_dev_printk_level(dev_alert
, KERN_ALERT
);
2959 define_dev_printk_level(dev_crit
, KERN_CRIT
);
2960 define_dev_printk_level(dev_err
, KERN_ERR
);
2961 define_dev_printk_level(dev_warn
, KERN_WARNING
);
2962 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
2963 define_dev_printk_level(_dev_info
, KERN_INFO
);
2967 static inline bool fwnode_is_primary(struct fwnode_handle
*fwnode
)
2969 return fwnode
&& !IS_ERR(fwnode
->secondary
);
2973 * set_primary_fwnode - Change the primary firmware node of a given device.
2974 * @dev: Device to handle.
2975 * @fwnode: New primary firmware node of the device.
2977 * Set the device's firmware node pointer to @fwnode, but if a secondary
2978 * firmware node of the device is present, preserve it.
2980 void set_primary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
2983 struct fwnode_handle
*fn
= dev
->fwnode
;
2985 if (fwnode_is_primary(fn
))
2989 WARN_ON(fwnode
->secondary
);
2990 fwnode
->secondary
= fn
;
2992 dev
->fwnode
= fwnode
;
2994 dev
->fwnode
= fwnode_is_primary(dev
->fwnode
) ?
2995 dev
->fwnode
->secondary
: NULL
;
2998 EXPORT_SYMBOL_GPL(set_primary_fwnode
);
3001 * set_secondary_fwnode - Change the secondary firmware node of a given device.
3002 * @dev: Device to handle.
3003 * @fwnode: New secondary firmware node of the device.
3005 * If a primary firmware node of the device is present, set its secondary
3006 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
3009 void set_secondary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
3012 fwnode
->secondary
= ERR_PTR(-ENODEV
);
3014 if (fwnode_is_primary(dev
->fwnode
))
3015 dev
->fwnode
->secondary
= fwnode
;
3017 dev
->fwnode
= fwnode
;