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 * If the link is being added by the consumer driver at probe
222 * time, balance the decrementation of the supplier's runtime PM
223 * usage counter after consumer probe in driver_probe_device().
225 if (consumer
->links
.status
== DL_DEV_PROBING
)
226 pm_runtime_get_noresume(supplier
);
228 get_device(supplier
);
229 link
->supplier
= supplier
;
230 INIT_LIST_HEAD(&link
->s_node
);
231 get_device(consumer
);
232 link
->consumer
= consumer
;
233 INIT_LIST_HEAD(&link
->c_node
);
236 /* Determine the initial link state. */
237 if (flags
& DL_FLAG_STATELESS
) {
238 link
->status
= DL_STATE_NONE
;
240 switch (supplier
->links
.status
) {
241 case DL_DEV_DRIVER_BOUND
:
242 switch (consumer
->links
.status
) {
245 * Some callers expect the link creation during
246 * consumer driver probe to resume the supplier
247 * even without DL_FLAG_RPM_ACTIVE.
249 if (flags
& DL_FLAG_PM_RUNTIME
)
250 pm_runtime_resume(supplier
);
252 link
->status
= DL_STATE_CONSUMER_PROBE
;
254 case DL_DEV_DRIVER_BOUND
:
255 link
->status
= DL_STATE_ACTIVE
;
258 link
->status
= DL_STATE_AVAILABLE
;
262 case DL_DEV_UNBINDING
:
263 link
->status
= DL_STATE_SUPPLIER_UNBIND
;
266 link
->status
= DL_STATE_DORMANT
;
272 * Move the consumer and all of the devices depending on it to the end
273 * of dpm_list and the devices_kset list.
275 * It is necessary to hold dpm_list locked throughout all that or else
276 * we may end up suspending with a wrong ordering of it.
278 device_reorder_to_tail(consumer
, NULL
);
280 list_add_tail_rcu(&link
->s_node
, &supplier
->links
.consumers
);
281 list_add_tail_rcu(&link
->c_node
, &consumer
->links
.suppliers
);
283 dev_info(consumer
, "Linked as a consumer to %s\n", dev_name(supplier
));
287 device_links_write_unlock();
290 EXPORT_SYMBOL_GPL(device_link_add
);
292 static void device_link_free(struct device_link
*link
)
294 put_device(link
->consumer
);
295 put_device(link
->supplier
);
300 static void __device_link_free_srcu(struct rcu_head
*rhead
)
302 device_link_free(container_of(rhead
, struct device_link
, rcu_head
));
305 static void __device_link_del(struct device_link
*link
)
307 dev_info(link
->consumer
, "Dropping the link to %s\n",
308 dev_name(link
->supplier
));
310 if (link
->flags
& DL_FLAG_PM_RUNTIME
)
311 pm_runtime_drop_link(link
->consumer
);
313 list_del_rcu(&link
->s_node
);
314 list_del_rcu(&link
->c_node
);
315 call_srcu(&device_links_srcu
, &link
->rcu_head
, __device_link_free_srcu
);
317 #else /* !CONFIG_SRCU */
318 static void __device_link_del(struct device_link
*link
)
320 dev_info(link
->consumer
, "Dropping the link to %s\n",
321 dev_name(link
->supplier
));
323 if (link
->flags
& DL_FLAG_PM_RUNTIME
)
324 pm_runtime_drop_link(link
->consumer
);
326 list_del(&link
->s_node
);
327 list_del(&link
->c_node
);
328 device_link_free(link
);
330 #endif /* !CONFIG_SRCU */
333 * device_link_del - Delete a link between two devices.
334 * @link: Device link to delete.
336 * The caller must ensure proper synchronization of this function with runtime
339 void device_link_del(struct device_link
*link
)
341 device_links_write_lock();
343 __device_link_del(link
);
345 device_links_write_unlock();
347 EXPORT_SYMBOL_GPL(device_link_del
);
349 static void device_links_missing_supplier(struct device
*dev
)
351 struct device_link
*link
;
353 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
)
354 if (link
->status
== DL_STATE_CONSUMER_PROBE
)
355 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
359 * device_links_check_suppliers - Check presence of supplier drivers.
360 * @dev: Consumer device.
362 * Check links from this device to any suppliers. Walk the list of the device's
363 * links to suppliers and see if all of them are available. If not, simply
364 * return -EPROBE_DEFER.
366 * We need to guarantee that the supplier will not go away after the check has
367 * been positive here. It only can go away in __device_release_driver() and
368 * that function checks the device's links to consumers. This means we need to
369 * mark the link as "consumer probe in progress" to make the supplier removal
370 * wait for us to complete (or bad things may happen).
372 * Links with the DL_FLAG_STATELESS flag set are ignored.
374 int device_links_check_suppliers(struct device
*dev
)
376 struct device_link
*link
;
379 device_links_write_lock();
381 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
) {
382 if (link
->flags
& DL_FLAG_STATELESS
)
385 if (link
->status
!= DL_STATE_AVAILABLE
) {
386 device_links_missing_supplier(dev
);
390 WRITE_ONCE(link
->status
, DL_STATE_CONSUMER_PROBE
);
392 dev
->links
.status
= DL_DEV_PROBING
;
394 device_links_write_unlock();
399 * device_links_driver_bound - Update device links after probing its driver.
400 * @dev: Device to update the links for.
402 * The probe has been successful, so update links from this device to any
403 * consumers by changing their status to "available".
405 * Also change the status of @dev's links to suppliers to "active".
407 * Links with the DL_FLAG_STATELESS flag set are ignored.
409 void device_links_driver_bound(struct device
*dev
)
411 struct device_link
*link
;
413 device_links_write_lock();
415 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
416 if (link
->flags
& DL_FLAG_STATELESS
)
419 WARN_ON(link
->status
!= DL_STATE_DORMANT
);
420 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
423 list_for_each_entry(link
, &dev
->links
.suppliers
, c_node
) {
424 if (link
->flags
& DL_FLAG_STATELESS
)
427 WARN_ON(link
->status
!= DL_STATE_CONSUMER_PROBE
);
428 WRITE_ONCE(link
->status
, DL_STATE_ACTIVE
);
431 dev
->links
.status
= DL_DEV_DRIVER_BOUND
;
433 device_links_write_unlock();
437 * __device_links_no_driver - Update links of a device without a driver.
438 * @dev: Device without a drvier.
440 * Delete all non-persistent links from this device to any suppliers.
442 * Persistent links stay around, but their status is changed to "available",
443 * unless they already are in the "supplier unbind in progress" state in which
444 * case they need not be updated.
446 * Links with the DL_FLAG_STATELESS flag set are ignored.
448 static void __device_links_no_driver(struct device
*dev
)
450 struct device_link
*link
, *ln
;
452 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.suppliers
, c_node
) {
453 if (link
->flags
& DL_FLAG_STATELESS
)
456 if (link
->flags
& DL_FLAG_AUTOREMOVE
)
457 __device_link_del(link
);
458 else if (link
->status
!= DL_STATE_SUPPLIER_UNBIND
)
459 WRITE_ONCE(link
->status
, DL_STATE_AVAILABLE
);
462 dev
->links
.status
= DL_DEV_NO_DRIVER
;
465 void device_links_no_driver(struct device
*dev
)
467 device_links_write_lock();
468 __device_links_no_driver(dev
);
469 device_links_write_unlock();
473 * device_links_driver_cleanup - Update links after driver removal.
474 * @dev: Device whose driver has just gone away.
476 * Update links to consumers for @dev by changing their status to "dormant" and
477 * invoke %__device_links_no_driver() to update links to suppliers for it as
480 * Links with the DL_FLAG_STATELESS flag set are ignored.
482 void device_links_driver_cleanup(struct device
*dev
)
484 struct device_link
*link
;
486 device_links_write_lock();
488 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
489 if (link
->flags
& DL_FLAG_STATELESS
)
492 WARN_ON(link
->flags
& DL_FLAG_AUTOREMOVE
);
493 WARN_ON(link
->status
!= DL_STATE_SUPPLIER_UNBIND
);
494 WRITE_ONCE(link
->status
, DL_STATE_DORMANT
);
497 __device_links_no_driver(dev
);
499 device_links_write_unlock();
503 * device_links_busy - Check if there are any busy links to consumers.
504 * @dev: Device to check.
506 * Check each consumer of the device and return 'true' if its link's status
507 * is one of "consumer probe" or "active" (meaning that the given consumer is
508 * probing right now or its driver is present). Otherwise, change the link
509 * state to "supplier unbind" to prevent the consumer from being probed
510 * successfully going forward.
512 * Return 'false' if there are no probing or active consumers.
514 * Links with the DL_FLAG_STATELESS flag set are ignored.
516 bool device_links_busy(struct device
*dev
)
518 struct device_link
*link
;
521 device_links_write_lock();
523 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
524 if (link
->flags
& DL_FLAG_STATELESS
)
527 if (link
->status
== DL_STATE_CONSUMER_PROBE
528 || link
->status
== DL_STATE_ACTIVE
) {
532 WRITE_ONCE(link
->status
, DL_STATE_SUPPLIER_UNBIND
);
535 dev
->links
.status
= DL_DEV_UNBINDING
;
537 device_links_write_unlock();
542 * device_links_unbind_consumers - Force unbind consumers of the given device.
543 * @dev: Device to unbind the consumers of.
545 * Walk the list of links to consumers for @dev and if any of them is in the
546 * "consumer probe" state, wait for all device probes in progress to complete
549 * If that's not the case, change the status of the link to "supplier unbind"
550 * and check if the link was in the "active" state. If so, force the consumer
551 * driver to unbind and start over (the consumer will not re-probe as we have
552 * changed the state of the link already).
554 * Links with the DL_FLAG_STATELESS flag set are ignored.
556 void device_links_unbind_consumers(struct device
*dev
)
558 struct device_link
*link
;
561 device_links_write_lock();
563 list_for_each_entry(link
, &dev
->links
.consumers
, s_node
) {
564 enum device_link_state status
;
566 if (link
->flags
& DL_FLAG_STATELESS
)
569 status
= link
->status
;
570 if (status
== DL_STATE_CONSUMER_PROBE
) {
571 device_links_write_unlock();
573 wait_for_device_probe();
576 WRITE_ONCE(link
->status
, DL_STATE_SUPPLIER_UNBIND
);
577 if (status
== DL_STATE_ACTIVE
) {
578 struct device
*consumer
= link
->consumer
;
580 get_device(consumer
);
582 device_links_write_unlock();
584 device_release_driver_internal(consumer
, NULL
,
586 put_device(consumer
);
591 device_links_write_unlock();
595 * device_links_purge - Delete existing links to other devices.
596 * @dev: Target device.
598 static void device_links_purge(struct device
*dev
)
600 struct device_link
*link
, *ln
;
603 * Delete all of the remaining links from this device to any other
604 * devices (either consumers or suppliers).
606 device_links_write_lock();
608 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.suppliers
, c_node
) {
609 WARN_ON(link
->status
== DL_STATE_ACTIVE
);
610 __device_link_del(link
);
613 list_for_each_entry_safe_reverse(link
, ln
, &dev
->links
.consumers
, s_node
) {
614 WARN_ON(link
->status
!= DL_STATE_DORMANT
&&
615 link
->status
!= DL_STATE_NONE
);
616 __device_link_del(link
);
619 device_links_write_unlock();
622 /* Device links support end. */
624 int (*platform_notify
)(struct device
*dev
) = NULL
;
625 int (*platform_notify_remove
)(struct device
*dev
) = NULL
;
626 static struct kobject
*dev_kobj
;
627 struct kobject
*sysfs_dev_char_kobj
;
628 struct kobject
*sysfs_dev_block_kobj
;
630 static DEFINE_MUTEX(device_hotplug_lock
);
632 void lock_device_hotplug(void)
634 mutex_lock(&device_hotplug_lock
);
637 void unlock_device_hotplug(void)
639 mutex_unlock(&device_hotplug_lock
);
642 int lock_device_hotplug_sysfs(void)
644 if (mutex_trylock(&device_hotplug_lock
))
647 /* Avoid busy looping (5 ms of sleep should do). */
649 return restart_syscall();
653 static inline int device_is_not_partition(struct device
*dev
)
655 return !(dev
->type
== &part_type
);
658 static inline int device_is_not_partition(struct device
*dev
)
665 * dev_driver_string - Return a device's driver name, if at all possible
666 * @dev: struct device to get the name of
668 * Will return the device's driver's name if it is bound to a device. If
669 * the device is not bound to a driver, it will return the name of the bus
670 * it is attached to. If it is not attached to a bus either, an empty
671 * string will be returned.
673 const char *dev_driver_string(const struct device
*dev
)
675 struct device_driver
*drv
;
677 /* dev->driver can change to NULL underneath us because of unbinding,
678 * so be careful about accessing it. dev->bus and dev->class should
679 * never change once they are set, so they don't need special care.
681 drv
= READ_ONCE(dev
->driver
);
682 return drv
? drv
->name
:
683 (dev
->bus
? dev
->bus
->name
:
684 (dev
->class ? dev
->class->name
: ""));
686 EXPORT_SYMBOL(dev_driver_string
);
688 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
690 static ssize_t
dev_attr_show(struct kobject
*kobj
, struct attribute
*attr
,
693 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
694 struct device
*dev
= kobj_to_dev(kobj
);
698 ret
= dev_attr
->show(dev
, dev_attr
, buf
);
699 if (ret
>= (ssize_t
)PAGE_SIZE
) {
700 print_symbol("dev_attr_show: %s returned bad count\n",
701 (unsigned long)dev_attr
->show
);
706 static ssize_t
dev_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
707 const char *buf
, size_t count
)
709 struct device_attribute
*dev_attr
= to_dev_attr(attr
);
710 struct device
*dev
= kobj_to_dev(kobj
);
714 ret
= dev_attr
->store(dev
, dev_attr
, buf
, count
);
718 static const struct sysfs_ops dev_sysfs_ops
= {
719 .show
= dev_attr_show
,
720 .store
= dev_attr_store
,
723 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
725 ssize_t
device_store_ulong(struct device
*dev
,
726 struct device_attribute
*attr
,
727 const char *buf
, size_t size
)
729 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
731 unsigned long new = simple_strtoul(buf
, &end
, 0);
734 *(unsigned long *)(ea
->var
) = new;
735 /* Always return full write size even if we didn't consume all */
738 EXPORT_SYMBOL_GPL(device_store_ulong
);
740 ssize_t
device_show_ulong(struct device
*dev
,
741 struct device_attribute
*attr
,
744 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
745 return snprintf(buf
, PAGE_SIZE
, "%lx\n", *(unsigned long *)(ea
->var
));
747 EXPORT_SYMBOL_GPL(device_show_ulong
);
749 ssize_t
device_store_int(struct device
*dev
,
750 struct device_attribute
*attr
,
751 const char *buf
, size_t size
)
753 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
755 long new = simple_strtol(buf
, &end
, 0);
756 if (end
== buf
|| new > INT_MAX
|| new < INT_MIN
)
758 *(int *)(ea
->var
) = new;
759 /* Always return full write size even if we didn't consume all */
762 EXPORT_SYMBOL_GPL(device_store_int
);
764 ssize_t
device_show_int(struct device
*dev
,
765 struct device_attribute
*attr
,
768 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
770 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(int *)(ea
->var
));
772 EXPORT_SYMBOL_GPL(device_show_int
);
774 ssize_t
device_store_bool(struct device
*dev
, struct device_attribute
*attr
,
775 const char *buf
, size_t size
)
777 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
779 if (strtobool(buf
, ea
->var
) < 0)
784 EXPORT_SYMBOL_GPL(device_store_bool
);
786 ssize_t
device_show_bool(struct device
*dev
, struct device_attribute
*attr
,
789 struct dev_ext_attribute
*ea
= to_ext_attr(attr
);
791 return snprintf(buf
, PAGE_SIZE
, "%d\n", *(bool *)(ea
->var
));
793 EXPORT_SYMBOL_GPL(device_show_bool
);
796 * device_release - free device structure.
797 * @kobj: device's kobject.
799 * This is called once the reference count for the object
800 * reaches 0. We forward the call to the device's release
801 * method, which should handle actually freeing the structure.
803 static void device_release(struct kobject
*kobj
)
805 struct device
*dev
= kobj_to_dev(kobj
);
806 struct device_private
*p
= dev
->p
;
809 * Some platform devices are driven without driver attached
810 * and managed resources may have been acquired. Make sure
811 * all resources are released.
813 * Drivers still can add resources into device after device
814 * is deleted but alive, so release devres here to avoid
815 * possible memory leak.
817 devres_release_all(dev
);
821 else if (dev
->type
&& dev
->type
->release
)
822 dev
->type
->release(dev
);
823 else if (dev
->class && dev
->class->dev_release
)
824 dev
->class->dev_release(dev
);
826 WARN(1, KERN_ERR
"Device '%s' does not have a release() "
827 "function, it is broken and must be fixed.\n",
832 static const void *device_namespace(struct kobject
*kobj
)
834 struct device
*dev
= kobj_to_dev(kobj
);
835 const void *ns
= NULL
;
837 if (dev
->class && dev
->class->ns_type
)
838 ns
= dev
->class->namespace(dev
);
843 static void device_get_ownership(struct kobject
*kobj
, kuid_t
*uid
, kgid_t
*gid
)
845 struct device
*dev
= kobj_to_dev(kobj
);
847 if (dev
->class && dev
->class->get_ownership
)
848 dev
->class->get_ownership(dev
, uid
, gid
);
851 static struct kobj_type device_ktype
= {
852 .release
= device_release
,
853 .sysfs_ops
= &dev_sysfs_ops
,
854 .namespace = device_namespace
,
855 .get_ownership
= device_get_ownership
,
859 static int dev_uevent_filter(struct kset
*kset
, struct kobject
*kobj
)
861 struct kobj_type
*ktype
= get_ktype(kobj
);
863 if (ktype
== &device_ktype
) {
864 struct device
*dev
= kobj_to_dev(kobj
);
873 static const char *dev_uevent_name(struct kset
*kset
, struct kobject
*kobj
)
875 struct device
*dev
= kobj_to_dev(kobj
);
878 return dev
->bus
->name
;
880 return dev
->class->name
;
884 static int dev_uevent(struct kset
*kset
, struct kobject
*kobj
,
885 struct kobj_uevent_env
*env
)
887 struct device
*dev
= kobj_to_dev(kobj
);
890 /* add device node properties if present */
891 if (MAJOR(dev
->devt
)) {
895 kuid_t uid
= GLOBAL_ROOT_UID
;
896 kgid_t gid
= GLOBAL_ROOT_GID
;
898 add_uevent_var(env
, "MAJOR=%u", MAJOR(dev
->devt
));
899 add_uevent_var(env
, "MINOR=%u", MINOR(dev
->devt
));
900 name
= device_get_devnode(dev
, &mode
, &uid
, &gid
, &tmp
);
902 add_uevent_var(env
, "DEVNAME=%s", name
);
904 add_uevent_var(env
, "DEVMODE=%#o", mode
& 0777);
905 if (!uid_eq(uid
, GLOBAL_ROOT_UID
))
906 add_uevent_var(env
, "DEVUID=%u", from_kuid(&init_user_ns
, uid
));
907 if (!gid_eq(gid
, GLOBAL_ROOT_GID
))
908 add_uevent_var(env
, "DEVGID=%u", from_kgid(&init_user_ns
, gid
));
913 if (dev
->type
&& dev
->type
->name
)
914 add_uevent_var(env
, "DEVTYPE=%s", dev
->type
->name
);
917 add_uevent_var(env
, "DRIVER=%s", dev
->driver
->name
);
919 /* Add common DT information about the device */
920 of_device_uevent(dev
, env
);
922 /* have the bus specific function add its stuff */
923 if (dev
->bus
&& dev
->bus
->uevent
) {
924 retval
= dev
->bus
->uevent(dev
, env
);
926 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
927 dev_name(dev
), __func__
, retval
);
930 /* have the class specific function add its stuff */
931 if (dev
->class && dev
->class->dev_uevent
) {
932 retval
= dev
->class->dev_uevent(dev
, env
);
934 pr_debug("device: '%s': %s: class uevent() "
935 "returned %d\n", dev_name(dev
),
939 /* have the device type specific function add its stuff */
940 if (dev
->type
&& dev
->type
->uevent
) {
941 retval
= dev
->type
->uevent(dev
, env
);
943 pr_debug("device: '%s': %s: dev_type uevent() "
944 "returned %d\n", dev_name(dev
),
951 static const struct kset_uevent_ops device_uevent_ops
= {
952 .filter
= dev_uevent_filter
,
953 .name
= dev_uevent_name
,
954 .uevent
= dev_uevent
,
957 static ssize_t
uevent_show(struct device
*dev
, struct device_attribute
*attr
,
960 struct kobject
*top_kobj
;
962 struct kobj_uevent_env
*env
= NULL
;
967 /* search the kset, the device belongs to */
968 top_kobj
= &dev
->kobj
;
969 while (!top_kobj
->kset
&& top_kobj
->parent
)
970 top_kobj
= top_kobj
->parent
;
974 kset
= top_kobj
->kset
;
975 if (!kset
->uevent_ops
|| !kset
->uevent_ops
->uevent
)
979 if (kset
->uevent_ops
&& kset
->uevent_ops
->filter
)
980 if (!kset
->uevent_ops
->filter(kset
, &dev
->kobj
))
983 env
= kzalloc(sizeof(struct kobj_uevent_env
), GFP_KERNEL
);
987 /* let the kset specific function add its keys */
988 retval
= kset
->uevent_ops
->uevent(kset
, &dev
->kobj
, env
);
992 /* copy keys to file */
993 for (i
= 0; i
< env
->envp_idx
; i
++)
994 count
+= sprintf(&buf
[count
], "%s\n", env
->envp
[i
]);
1000 static ssize_t
uevent_store(struct device
*dev
, struct device_attribute
*attr
,
1001 const char *buf
, size_t count
)
1005 rc
= kobject_synth_uevent(&dev
->kobj
, buf
, count
);
1008 dev_err(dev
, "uevent: failed to send synthetic uevent\n");
1014 static DEVICE_ATTR_RW(uevent
);
1016 static ssize_t
online_show(struct device
*dev
, struct device_attribute
*attr
,
1022 val
= !dev
->offline
;
1024 return sprintf(buf
, "%u\n", val
);
1027 static ssize_t
online_store(struct device
*dev
, struct device_attribute
*attr
,
1028 const char *buf
, size_t count
)
1033 ret
= strtobool(buf
, &val
);
1037 ret
= lock_device_hotplug_sysfs();
1041 ret
= val
? device_online(dev
) : device_offline(dev
);
1042 unlock_device_hotplug();
1043 return ret
< 0 ? ret
: count
;
1045 static DEVICE_ATTR_RW(online
);
1047 int device_add_groups(struct device
*dev
, const struct attribute_group
**groups
)
1049 return sysfs_create_groups(&dev
->kobj
, groups
);
1051 EXPORT_SYMBOL_GPL(device_add_groups
);
1053 void device_remove_groups(struct device
*dev
,
1054 const struct attribute_group
**groups
)
1056 sysfs_remove_groups(&dev
->kobj
, groups
);
1058 EXPORT_SYMBOL_GPL(device_remove_groups
);
1060 union device_attr_group_devres
{
1061 const struct attribute_group
*group
;
1062 const struct attribute_group
**groups
;
1065 static int devm_attr_group_match(struct device
*dev
, void *res
, void *data
)
1067 return ((union device_attr_group_devres
*)res
)->group
== data
;
1070 static void devm_attr_group_remove(struct device
*dev
, void *res
)
1072 union device_attr_group_devres
*devres
= res
;
1073 const struct attribute_group
*group
= devres
->group
;
1075 dev_dbg(dev
, "%s: removing group %p\n", __func__
, group
);
1076 sysfs_remove_group(&dev
->kobj
, group
);
1079 static void devm_attr_groups_remove(struct device
*dev
, void *res
)
1081 union device_attr_group_devres
*devres
= res
;
1082 const struct attribute_group
**groups
= devres
->groups
;
1084 dev_dbg(dev
, "%s: removing groups %p\n", __func__
, groups
);
1085 sysfs_remove_groups(&dev
->kobj
, groups
);
1089 * devm_device_add_group - given a device, create a managed attribute group
1090 * @dev: The device to create the group for
1091 * @grp: The attribute group to create
1093 * This function creates a group for the first time. It will explicitly
1094 * warn and error if any of the attribute files being created already exist.
1096 * Returns 0 on success or error code on failure.
1098 int devm_device_add_group(struct device
*dev
, const struct attribute_group
*grp
)
1100 union device_attr_group_devres
*devres
;
1103 devres
= devres_alloc(devm_attr_group_remove
,
1104 sizeof(*devres
), GFP_KERNEL
);
1108 error
= sysfs_create_group(&dev
->kobj
, grp
);
1110 devres_free(devres
);
1114 devres
->group
= grp
;
1115 devres_add(dev
, devres
);
1118 EXPORT_SYMBOL_GPL(devm_device_add_group
);
1121 * devm_device_remove_group: remove a managed group from a device
1122 * @dev: device to remove the group from
1123 * @grp: group to remove
1125 * This function removes a group of attributes from a device. The attributes
1126 * previously have to have been created for this group, otherwise it will fail.
1128 void devm_device_remove_group(struct device
*dev
,
1129 const struct attribute_group
*grp
)
1131 WARN_ON(devres_release(dev
, devm_attr_group_remove
,
1132 devm_attr_group_match
,
1133 /* cast away const */ (void *)grp
));
1135 EXPORT_SYMBOL_GPL(devm_device_remove_group
);
1138 * devm_device_add_groups - create a bunch of managed attribute groups
1139 * @dev: The device to create the group for
1140 * @groups: The attribute groups to create, NULL terminated
1142 * This function creates a bunch of managed attribute groups. If an error
1143 * occurs when creating a group, all previously created groups will be
1144 * removed, unwinding everything back to the original state when this
1145 * function was called. It will explicitly warn and error if any of the
1146 * attribute files being created already exist.
1148 * Returns 0 on success or error code from sysfs_create_group on failure.
1150 int devm_device_add_groups(struct device
*dev
,
1151 const struct attribute_group
**groups
)
1153 union device_attr_group_devres
*devres
;
1156 devres
= devres_alloc(devm_attr_groups_remove
,
1157 sizeof(*devres
), GFP_KERNEL
);
1161 error
= sysfs_create_groups(&dev
->kobj
, groups
);
1163 devres_free(devres
);
1167 devres
->groups
= groups
;
1168 devres_add(dev
, devres
);
1171 EXPORT_SYMBOL_GPL(devm_device_add_groups
);
1174 * devm_device_remove_groups - remove a list of managed groups
1176 * @dev: The device for the groups to be removed from
1177 * @groups: NULL terminated list of groups to be removed
1179 * If groups is not NULL, remove the specified groups from the device.
1181 void devm_device_remove_groups(struct device
*dev
,
1182 const struct attribute_group
**groups
)
1184 WARN_ON(devres_release(dev
, devm_attr_groups_remove
,
1185 devm_attr_group_match
,
1186 /* cast away const */ (void *)groups
));
1188 EXPORT_SYMBOL_GPL(devm_device_remove_groups
);
1190 static int device_add_attrs(struct device
*dev
)
1192 struct class *class = dev
->class;
1193 const struct device_type
*type
= dev
->type
;
1197 error
= device_add_groups(dev
, class->dev_groups
);
1203 error
= device_add_groups(dev
, type
->groups
);
1205 goto err_remove_class_groups
;
1208 error
= device_add_groups(dev
, dev
->groups
);
1210 goto err_remove_type_groups
;
1212 if (device_supports_offline(dev
) && !dev
->offline_disabled
) {
1213 error
= device_create_file(dev
, &dev_attr_online
);
1215 goto err_remove_dev_groups
;
1220 err_remove_dev_groups
:
1221 device_remove_groups(dev
, dev
->groups
);
1222 err_remove_type_groups
:
1224 device_remove_groups(dev
, type
->groups
);
1225 err_remove_class_groups
:
1227 device_remove_groups(dev
, class->dev_groups
);
1232 static void device_remove_attrs(struct device
*dev
)
1234 struct class *class = dev
->class;
1235 const struct device_type
*type
= dev
->type
;
1237 device_remove_file(dev
, &dev_attr_online
);
1238 device_remove_groups(dev
, dev
->groups
);
1241 device_remove_groups(dev
, type
->groups
);
1244 device_remove_groups(dev
, class->dev_groups
);
1247 static ssize_t
dev_show(struct device
*dev
, struct device_attribute
*attr
,
1250 return print_dev_t(buf
, dev
->devt
);
1252 static DEVICE_ATTR_RO(dev
);
1255 struct kset
*devices_kset
;
1258 * devices_kset_move_before - Move device in the devices_kset's list.
1259 * @deva: Device to move.
1260 * @devb: Device @deva should come before.
1262 static void devices_kset_move_before(struct device
*deva
, struct device
*devb
)
1266 pr_debug("devices_kset: Moving %s before %s\n",
1267 dev_name(deva
), dev_name(devb
));
1268 spin_lock(&devices_kset
->list_lock
);
1269 list_move_tail(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1270 spin_unlock(&devices_kset
->list_lock
);
1274 * devices_kset_move_after - Move device in the devices_kset's list.
1275 * @deva: Device to move
1276 * @devb: Device @deva should come after.
1278 static void devices_kset_move_after(struct device
*deva
, struct device
*devb
)
1282 pr_debug("devices_kset: Moving %s after %s\n",
1283 dev_name(deva
), dev_name(devb
));
1284 spin_lock(&devices_kset
->list_lock
);
1285 list_move(&deva
->kobj
.entry
, &devb
->kobj
.entry
);
1286 spin_unlock(&devices_kset
->list_lock
);
1290 * devices_kset_move_last - move the device to the end of devices_kset's list.
1291 * @dev: device to move
1293 void devices_kset_move_last(struct device
*dev
)
1297 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev
));
1298 spin_lock(&devices_kset
->list_lock
);
1299 list_move_tail(&dev
->kobj
.entry
, &devices_kset
->list
);
1300 spin_unlock(&devices_kset
->list_lock
);
1304 * device_create_file - create sysfs attribute file for device.
1306 * @attr: device attribute descriptor.
1308 int device_create_file(struct device
*dev
,
1309 const struct device_attribute
*attr
)
1314 WARN(((attr
->attr
.mode
& S_IWUGO
) && !attr
->store
),
1315 "Attribute %s: write permission without 'store'\n",
1317 WARN(((attr
->attr
.mode
& S_IRUGO
) && !attr
->show
),
1318 "Attribute %s: read permission without 'show'\n",
1320 error
= sysfs_create_file(&dev
->kobj
, &attr
->attr
);
1325 EXPORT_SYMBOL_GPL(device_create_file
);
1328 * device_remove_file - remove sysfs attribute file.
1330 * @attr: device attribute descriptor.
1332 void device_remove_file(struct device
*dev
,
1333 const struct device_attribute
*attr
)
1336 sysfs_remove_file(&dev
->kobj
, &attr
->attr
);
1338 EXPORT_SYMBOL_GPL(device_remove_file
);
1341 * device_remove_file_self - remove sysfs attribute file from its own method.
1343 * @attr: device attribute descriptor.
1345 * See kernfs_remove_self() for details.
1347 bool device_remove_file_self(struct device
*dev
,
1348 const struct device_attribute
*attr
)
1351 return sysfs_remove_file_self(&dev
->kobj
, &attr
->attr
);
1355 EXPORT_SYMBOL_GPL(device_remove_file_self
);
1358 * device_create_bin_file - create sysfs binary attribute file for device.
1360 * @attr: device binary attribute descriptor.
1362 int device_create_bin_file(struct device
*dev
,
1363 const struct bin_attribute
*attr
)
1365 int error
= -EINVAL
;
1367 error
= sysfs_create_bin_file(&dev
->kobj
, attr
);
1370 EXPORT_SYMBOL_GPL(device_create_bin_file
);
1373 * device_remove_bin_file - remove sysfs binary attribute file
1375 * @attr: device binary attribute descriptor.
1377 void device_remove_bin_file(struct device
*dev
,
1378 const struct bin_attribute
*attr
)
1381 sysfs_remove_bin_file(&dev
->kobj
, attr
);
1383 EXPORT_SYMBOL_GPL(device_remove_bin_file
);
1385 static void klist_children_get(struct klist_node
*n
)
1387 struct device_private
*p
= to_device_private_parent(n
);
1388 struct device
*dev
= p
->device
;
1393 static void klist_children_put(struct klist_node
*n
)
1395 struct device_private
*p
= to_device_private_parent(n
);
1396 struct device
*dev
= p
->device
;
1402 * device_initialize - init device structure.
1405 * This prepares the device for use by other layers by initializing
1407 * It is the first half of device_register(), if called by
1408 * that function, though it can also be called separately, so one
1409 * may use @dev's fields. In particular, get_device()/put_device()
1410 * may be used for reference counting of @dev after calling this
1413 * All fields in @dev must be initialized by the caller to 0, except
1414 * for those explicitly set to some other value. The simplest
1415 * approach is to use kzalloc() to allocate the structure containing
1418 * NOTE: Use put_device() to give up your reference instead of freeing
1419 * @dev directly once you have called this function.
1421 void device_initialize(struct device
*dev
)
1423 dev
->kobj
.kset
= devices_kset
;
1424 kobject_init(&dev
->kobj
, &device_ktype
);
1425 INIT_LIST_HEAD(&dev
->dma_pools
);
1426 mutex_init(&dev
->mutex
);
1427 lockdep_set_novalidate_class(&dev
->mutex
);
1428 spin_lock_init(&dev
->devres_lock
);
1429 INIT_LIST_HEAD(&dev
->devres_head
);
1430 device_pm_init(dev
);
1431 set_dev_node(dev
, -1);
1432 #ifdef CONFIG_GENERIC_MSI_IRQ
1433 INIT_LIST_HEAD(&dev
->msi_list
);
1435 INIT_LIST_HEAD(&dev
->links
.consumers
);
1436 INIT_LIST_HEAD(&dev
->links
.suppliers
);
1437 dev
->links
.status
= DL_DEV_NO_DRIVER
;
1439 EXPORT_SYMBOL_GPL(device_initialize
);
1441 struct kobject
*virtual_device_parent(struct device
*dev
)
1443 static struct kobject
*virtual_dir
= NULL
;
1446 virtual_dir
= kobject_create_and_add("virtual",
1447 &devices_kset
->kobj
);
1453 struct kobject kobj
;
1454 struct class *class;
1457 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
1459 static void class_dir_release(struct kobject
*kobj
)
1461 struct class_dir
*dir
= to_class_dir(kobj
);
1466 struct kobj_ns_type_operations
*class_dir_child_ns_type(struct kobject
*kobj
)
1468 struct class_dir
*dir
= to_class_dir(kobj
);
1469 return dir
->class->ns_type
;
1472 static struct kobj_type class_dir_ktype
= {
1473 .release
= class_dir_release
,
1474 .sysfs_ops
= &kobj_sysfs_ops
,
1475 .child_ns_type
= class_dir_child_ns_type
1478 static struct kobject
*
1479 class_dir_create_and_add(struct class *class, struct kobject
*parent_kobj
)
1481 struct class_dir
*dir
;
1484 dir
= kzalloc(sizeof(*dir
), GFP_KERNEL
);
1486 return ERR_PTR(-ENOMEM
);
1489 kobject_init(&dir
->kobj
, &class_dir_ktype
);
1491 dir
->kobj
.kset
= &class->p
->glue_dirs
;
1493 retval
= kobject_add(&dir
->kobj
, parent_kobj
, "%s", class->name
);
1495 kobject_put(&dir
->kobj
);
1496 return ERR_PTR(retval
);
1501 static DEFINE_MUTEX(gdp_mutex
);
1503 static struct kobject
*get_device_parent(struct device
*dev
,
1504 struct device
*parent
)
1507 struct kobject
*kobj
= NULL
;
1508 struct kobject
*parent_kobj
;
1512 /* block disks show up in /sys/block */
1513 if (sysfs_deprecated
&& dev
->class == &block_class
) {
1514 if (parent
&& parent
->class == &block_class
)
1515 return &parent
->kobj
;
1516 return &block_class
.p
->subsys
.kobj
;
1521 * If we have no parent, we live in "virtual".
1522 * Class-devices with a non class-device as parent, live
1523 * in a "glue" directory to prevent namespace collisions.
1526 parent_kobj
= virtual_device_parent(dev
);
1527 else if (parent
->class && !dev
->class->ns_type
)
1528 return &parent
->kobj
;
1530 parent_kobj
= &parent
->kobj
;
1532 mutex_lock(&gdp_mutex
);
1534 /* find our class-directory at the parent and reference it */
1535 spin_lock(&dev
->class->p
->glue_dirs
.list_lock
);
1536 list_for_each_entry(k
, &dev
->class->p
->glue_dirs
.list
, entry
)
1537 if (k
->parent
== parent_kobj
) {
1538 kobj
= kobject_get(k
);
1541 spin_unlock(&dev
->class->p
->glue_dirs
.list_lock
);
1543 mutex_unlock(&gdp_mutex
);
1547 /* or create a new class-directory at the parent device */
1548 k
= class_dir_create_and_add(dev
->class, parent_kobj
);
1549 /* do not emit an uevent for this simple "glue" directory */
1550 mutex_unlock(&gdp_mutex
);
1554 /* subsystems can specify a default root directory for their devices */
1555 if (!parent
&& dev
->bus
&& dev
->bus
->dev_root
)
1556 return &dev
->bus
->dev_root
->kobj
;
1559 return &parent
->kobj
;
1563 static inline bool live_in_glue_dir(struct kobject
*kobj
,
1566 if (!kobj
|| !dev
->class ||
1567 kobj
->kset
!= &dev
->class->p
->glue_dirs
)
1572 static inline struct kobject
*get_glue_dir(struct device
*dev
)
1574 return dev
->kobj
.parent
;
1578 * make sure cleaning up dir as the last step, we need to make
1579 * sure .release handler of kobject is run with holding the
1582 static void cleanup_glue_dir(struct device
*dev
, struct kobject
*glue_dir
)
1584 /* see if we live in a "glue" directory */
1585 if (!live_in_glue_dir(glue_dir
, dev
))
1588 mutex_lock(&gdp_mutex
);
1589 if (!kobject_has_children(glue_dir
))
1590 kobject_del(glue_dir
);
1591 kobject_put(glue_dir
);
1592 mutex_unlock(&gdp_mutex
);
1595 static int device_add_class_symlinks(struct device
*dev
)
1597 struct device_node
*of_node
= dev_of_node(dev
);
1601 error
= sysfs_create_link(&dev
->kobj
, of_node_kobj(of_node
), "of_node");
1603 dev_warn(dev
, "Error %d creating of_node link\n",error
);
1604 /* An error here doesn't warrant bringing down the device */
1610 error
= sysfs_create_link(&dev
->kobj
,
1611 &dev
->class->p
->subsys
.kobj
,
1616 if (dev
->parent
&& device_is_not_partition(dev
)) {
1617 error
= sysfs_create_link(&dev
->kobj
, &dev
->parent
->kobj
,
1624 /* /sys/block has directories and does not need symlinks */
1625 if (sysfs_deprecated
&& dev
->class == &block_class
)
1629 /* link in the class directory pointing to the device */
1630 error
= sysfs_create_link(&dev
->class->p
->subsys
.kobj
,
1631 &dev
->kobj
, dev_name(dev
));
1638 sysfs_remove_link(&dev
->kobj
, "device");
1641 sysfs_remove_link(&dev
->kobj
, "subsystem");
1643 sysfs_remove_link(&dev
->kobj
, "of_node");
1647 static void device_remove_class_symlinks(struct device
*dev
)
1649 if (dev_of_node(dev
))
1650 sysfs_remove_link(&dev
->kobj
, "of_node");
1655 if (dev
->parent
&& device_is_not_partition(dev
))
1656 sysfs_remove_link(&dev
->kobj
, "device");
1657 sysfs_remove_link(&dev
->kobj
, "subsystem");
1659 if (sysfs_deprecated
&& dev
->class == &block_class
)
1662 sysfs_delete_link(&dev
->class->p
->subsys
.kobj
, &dev
->kobj
, dev_name(dev
));
1666 * dev_set_name - set a device name
1668 * @fmt: format string for the device's name
1670 int dev_set_name(struct device
*dev
, const char *fmt
, ...)
1675 va_start(vargs
, fmt
);
1676 err
= kobject_set_name_vargs(&dev
->kobj
, fmt
, vargs
);
1680 EXPORT_SYMBOL_GPL(dev_set_name
);
1683 * device_to_dev_kobj - select a /sys/dev/ directory for the device
1686 * By default we select char/ for new entries. Setting class->dev_obj
1687 * to NULL prevents an entry from being created. class->dev_kobj must
1688 * be set (or cleared) before any devices are registered to the class
1689 * otherwise device_create_sys_dev_entry() and
1690 * device_remove_sys_dev_entry() will disagree about the presence of
1693 static struct kobject
*device_to_dev_kobj(struct device
*dev
)
1695 struct kobject
*kobj
;
1698 kobj
= dev
->class->dev_kobj
;
1700 kobj
= sysfs_dev_char_kobj
;
1705 static int device_create_sys_dev_entry(struct device
*dev
)
1707 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1712 format_dev_t(devt_str
, dev
->devt
);
1713 error
= sysfs_create_link(kobj
, &dev
->kobj
, devt_str
);
1719 static void device_remove_sys_dev_entry(struct device
*dev
)
1721 struct kobject
*kobj
= device_to_dev_kobj(dev
);
1725 format_dev_t(devt_str
, dev
->devt
);
1726 sysfs_remove_link(kobj
, devt_str
);
1730 int device_private_init(struct device
*dev
)
1732 dev
->p
= kzalloc(sizeof(*dev
->p
), GFP_KERNEL
);
1735 dev
->p
->device
= dev
;
1736 klist_init(&dev
->p
->klist_children
, klist_children_get
,
1737 klist_children_put
);
1738 INIT_LIST_HEAD(&dev
->p
->deferred_probe
);
1743 * device_add - add device to device hierarchy.
1746 * This is part 2 of device_register(), though may be called
1747 * separately _iff_ device_initialize() has been called separately.
1749 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
1750 * to the global and sibling lists for the device, then
1751 * adds it to the other relevant subsystems of the driver model.
1753 * Do not call this routine or device_register() more than once for
1754 * any device structure. The driver model core is not designed to work
1755 * with devices that get unregistered and then spring back to life.
1756 * (Among other things, it's very hard to guarantee that all references
1757 * to the previous incarnation of @dev have been dropped.) Allocate
1758 * and register a fresh new struct device instead.
1760 * NOTE: _Never_ directly free @dev after calling this function, even
1761 * if it returned an error! Always use put_device() to give up your
1762 * reference instead.
1764 int device_add(struct device
*dev
)
1766 struct device
*parent
;
1767 struct kobject
*kobj
;
1768 struct class_interface
*class_intf
;
1769 int error
= -EINVAL
;
1770 struct kobject
*glue_dir
= NULL
;
1772 dev
= get_device(dev
);
1777 error
= device_private_init(dev
);
1783 * for statically allocated devices, which should all be converted
1784 * some day, we need to initialize the name. We prevent reading back
1785 * the name, and force the use of dev_name()
1787 if (dev
->init_name
) {
1788 dev_set_name(dev
, "%s", dev
->init_name
);
1789 dev
->init_name
= NULL
;
1792 /* subsystems can specify simple device enumeration */
1793 if (!dev_name(dev
) && dev
->bus
&& dev
->bus
->dev_name
)
1794 dev_set_name(dev
, "%s%u", dev
->bus
->dev_name
, dev
->id
);
1796 if (!dev_name(dev
)) {
1801 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
1803 parent
= get_device(dev
->parent
);
1804 kobj
= get_device_parent(dev
, parent
);
1806 error
= PTR_ERR(kobj
);
1810 dev
->kobj
.parent
= kobj
;
1812 /* use parent numa_node */
1813 if (parent
&& (dev_to_node(dev
) == NUMA_NO_NODE
))
1814 set_dev_node(dev
, dev_to_node(parent
));
1816 /* first, register with generic layer. */
1817 /* we require the name to be set before, and pass NULL */
1818 error
= kobject_add(&dev
->kobj
, dev
->kobj
.parent
, NULL
);
1820 glue_dir
= get_glue_dir(dev
);
1824 /* notify platform of device entry */
1825 if (platform_notify
)
1826 platform_notify(dev
);
1828 error
= device_create_file(dev
, &dev_attr_uevent
);
1832 error
= device_add_class_symlinks(dev
);
1835 error
= device_add_attrs(dev
);
1838 error
= bus_add_device(dev
);
1841 error
= dpm_sysfs_add(dev
);
1846 if (MAJOR(dev
->devt
)) {
1847 error
= device_create_file(dev
, &dev_attr_dev
);
1851 error
= device_create_sys_dev_entry(dev
);
1855 devtmpfs_create_node(dev
);
1858 /* Notify clients of device addition. This call must come
1859 * after dpm_sysfs_add() and before kobject_uevent().
1862 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
1863 BUS_NOTIFY_ADD_DEVICE
, dev
);
1865 kobject_uevent(&dev
->kobj
, KOBJ_ADD
);
1866 bus_probe_device(dev
);
1868 klist_add_tail(&dev
->p
->knode_parent
,
1869 &parent
->p
->klist_children
);
1872 mutex_lock(&dev
->class->p
->mutex
);
1873 /* tie the class to the device */
1874 klist_add_tail(&dev
->knode_class
,
1875 &dev
->class->p
->klist_devices
);
1877 /* notify any interfaces that the device is here */
1878 list_for_each_entry(class_intf
,
1879 &dev
->class->p
->interfaces
, node
)
1880 if (class_intf
->add_dev
)
1881 class_intf
->add_dev(dev
, class_intf
);
1882 mutex_unlock(&dev
->class->p
->mutex
);
1888 if (MAJOR(dev
->devt
))
1889 device_remove_file(dev
, &dev_attr_dev
);
1891 device_pm_remove(dev
);
1892 dpm_sysfs_remove(dev
);
1894 bus_remove_device(dev
);
1896 device_remove_attrs(dev
);
1898 device_remove_class_symlinks(dev
);
1900 device_remove_file(dev
, &dev_attr_uevent
);
1902 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
1903 glue_dir
= get_glue_dir(dev
);
1904 kobject_del(&dev
->kobj
);
1906 cleanup_glue_dir(dev
, glue_dir
);
1914 EXPORT_SYMBOL_GPL(device_add
);
1917 * device_register - register a device with the system.
1918 * @dev: pointer to the device structure
1920 * This happens in two clean steps - initialize the device
1921 * and add it to the system. The two steps can be called
1922 * separately, but this is the easiest and most common.
1923 * I.e. you should only call the two helpers separately if
1924 * have a clearly defined need to use and refcount the device
1925 * before it is added to the hierarchy.
1927 * For more information, see the kerneldoc for device_initialize()
1930 * NOTE: _Never_ directly free @dev after calling this function, even
1931 * if it returned an error! Always use put_device() to give up the
1932 * reference initialized in this function instead.
1934 int device_register(struct device
*dev
)
1936 device_initialize(dev
);
1937 return device_add(dev
);
1939 EXPORT_SYMBOL_GPL(device_register
);
1942 * get_device - increment reference count for device.
1945 * This simply forwards the call to kobject_get(), though
1946 * we do take care to provide for the case that we get a NULL
1947 * pointer passed in.
1949 struct device
*get_device(struct device
*dev
)
1951 return dev
? kobj_to_dev(kobject_get(&dev
->kobj
)) : NULL
;
1953 EXPORT_SYMBOL_GPL(get_device
);
1956 * put_device - decrement reference count.
1957 * @dev: device in question.
1959 void put_device(struct device
*dev
)
1961 /* might_sleep(); */
1963 kobject_put(&dev
->kobj
);
1965 EXPORT_SYMBOL_GPL(put_device
);
1967 bool kill_device(struct device
*dev
)
1970 * Require the device lock and set the "dead" flag to guarantee that
1971 * the update behavior is consistent with the other bitfields near
1972 * it and that we cannot have an asynchronous probe routine trying
1973 * to run while we are tearing out the bus/class/sysfs from
1974 * underneath the device.
1976 lockdep_assert_held(&dev
->mutex
);
1980 dev
->p
->dead
= true;
1983 EXPORT_SYMBOL_GPL(kill_device
);
1986 * device_del - delete device from system.
1989 * This is the first part of the device unregistration
1990 * sequence. This removes the device from the lists we control
1991 * from here, has it removed from the other driver model
1992 * subsystems it was added to in device_add(), and removes it
1993 * from the kobject hierarchy.
1995 * NOTE: this should be called manually _iff_ device_add() was
1996 * also called manually.
1998 void device_del(struct device
*dev
)
2000 struct device
*parent
= dev
->parent
;
2001 struct kobject
*glue_dir
= NULL
;
2002 struct class_interface
*class_intf
;
2008 /* Notify clients of device removal. This call must come
2009 * before dpm_sysfs_remove().
2012 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
2013 BUS_NOTIFY_DEL_DEVICE
, dev
);
2015 dpm_sysfs_remove(dev
);
2017 klist_del(&dev
->p
->knode_parent
);
2018 if (MAJOR(dev
->devt
)) {
2019 devtmpfs_delete_node(dev
);
2020 device_remove_sys_dev_entry(dev
);
2021 device_remove_file(dev
, &dev_attr_dev
);
2024 device_remove_class_symlinks(dev
);
2026 mutex_lock(&dev
->class->p
->mutex
);
2027 /* notify any interfaces that the device is now gone */
2028 list_for_each_entry(class_intf
,
2029 &dev
->class->p
->interfaces
, node
)
2030 if (class_intf
->remove_dev
)
2031 class_intf
->remove_dev(dev
, class_intf
);
2032 /* remove the device from the class list */
2033 klist_del(&dev
->knode_class
);
2034 mutex_unlock(&dev
->class->p
->mutex
);
2036 device_remove_file(dev
, &dev_attr_uevent
);
2037 device_remove_attrs(dev
);
2038 bus_remove_device(dev
);
2039 device_pm_remove(dev
);
2040 driver_deferred_probe_del(dev
);
2041 device_remove_properties(dev
);
2042 device_links_purge(dev
);
2044 /* Notify the platform of the removal, in case they
2045 * need to do anything...
2047 if (platform_notify_remove
)
2048 platform_notify_remove(dev
);
2050 blocking_notifier_call_chain(&dev
->bus
->p
->bus_notifier
,
2051 BUS_NOTIFY_REMOVED_DEVICE
, dev
);
2052 kobject_uevent(&dev
->kobj
, KOBJ_REMOVE
);
2053 glue_dir
= get_glue_dir(dev
);
2054 kobject_del(&dev
->kobj
);
2055 cleanup_glue_dir(dev
, glue_dir
);
2058 EXPORT_SYMBOL_GPL(device_del
);
2061 * device_unregister - unregister device from system.
2062 * @dev: device going away.
2064 * We do this in two parts, like we do device_register(). First,
2065 * we remove it from all the subsystems with device_del(), then
2066 * we decrement the reference count via put_device(). If that
2067 * is the final reference count, the device will be cleaned up
2068 * via device_release() above. Otherwise, the structure will
2069 * stick around until the final reference to the device is dropped.
2071 void device_unregister(struct device
*dev
)
2073 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
2077 EXPORT_SYMBOL_GPL(device_unregister
);
2079 static struct device
*prev_device(struct klist_iter
*i
)
2081 struct klist_node
*n
= klist_prev(i
);
2082 struct device
*dev
= NULL
;
2083 struct device_private
*p
;
2086 p
= to_device_private_parent(n
);
2092 static struct device
*next_device(struct klist_iter
*i
)
2094 struct klist_node
*n
= klist_next(i
);
2095 struct device
*dev
= NULL
;
2096 struct device_private
*p
;
2099 p
= to_device_private_parent(n
);
2106 * device_get_devnode - path of device node file
2108 * @mode: returned file access mode
2109 * @uid: returned file owner
2110 * @gid: returned file group
2111 * @tmp: possibly allocated string
2113 * Return the relative path of a possible device node.
2114 * Non-default names may need to allocate a memory to compose
2115 * a name. This memory is returned in tmp and needs to be
2116 * freed by the caller.
2118 const char *device_get_devnode(struct device
*dev
,
2119 umode_t
*mode
, kuid_t
*uid
, kgid_t
*gid
,
2126 /* the device type may provide a specific name */
2127 if (dev
->type
&& dev
->type
->devnode
)
2128 *tmp
= dev
->type
->devnode(dev
, mode
, uid
, gid
);
2132 /* the class may provide a specific name */
2133 if (dev
->class && dev
->class->devnode
)
2134 *tmp
= dev
->class->devnode(dev
, mode
);
2138 /* return name without allocation, tmp == NULL */
2139 if (strchr(dev_name(dev
), '!') == NULL
)
2140 return dev_name(dev
);
2142 /* replace '!' in the name with '/' */
2143 s
= kstrdup(dev_name(dev
), GFP_KERNEL
);
2146 strreplace(s
, '!', '/');
2151 * device_for_each_child - device child iterator.
2152 * @parent: parent struct device.
2153 * @fn: function to be called for each device.
2154 * @data: data for the callback.
2156 * Iterate over @parent's child devices, and call @fn for each,
2159 * We check the return of @fn each time. If it returns anything
2160 * other than 0, we break out and return that value.
2162 int device_for_each_child(struct device
*parent
, void *data
,
2163 int (*fn
)(struct device
*dev
, void *data
))
2165 struct klist_iter i
;
2166 struct device
*child
;
2172 klist_iter_init(&parent
->p
->klist_children
, &i
);
2173 while ((child
= next_device(&i
)) && !error
)
2174 error
= fn(child
, data
);
2175 klist_iter_exit(&i
);
2178 EXPORT_SYMBOL_GPL(device_for_each_child
);
2181 * device_for_each_child_reverse - device child iterator in reversed order.
2182 * @parent: parent struct device.
2183 * @fn: function to be called for each device.
2184 * @data: data for the callback.
2186 * Iterate over @parent's child devices, and call @fn for each,
2189 * We check the return of @fn each time. If it returns anything
2190 * other than 0, we break out and return that value.
2192 int device_for_each_child_reverse(struct device
*parent
, void *data
,
2193 int (*fn
)(struct device
*dev
, void *data
))
2195 struct klist_iter i
;
2196 struct device
*child
;
2202 klist_iter_init(&parent
->p
->klist_children
, &i
);
2203 while ((child
= prev_device(&i
)) && !error
)
2204 error
= fn(child
, data
);
2205 klist_iter_exit(&i
);
2208 EXPORT_SYMBOL_GPL(device_for_each_child_reverse
);
2211 * device_find_child - device iterator for locating a particular device.
2212 * @parent: parent struct device
2213 * @match: Callback function to check device
2214 * @data: Data to pass to match function
2216 * This is similar to the device_for_each_child() function above, but it
2217 * returns a reference to a device that is 'found' for later use, as
2218 * determined by the @match callback.
2220 * The callback should return 0 if the device doesn't match and non-zero
2221 * if it does. If the callback returns non-zero and a reference to the
2222 * current device can be obtained, this function will return to the caller
2223 * and not iterate over any more devices.
2225 * NOTE: you will need to drop the reference with put_device() after use.
2227 struct device
*device_find_child(struct device
*parent
, void *data
,
2228 int (*match
)(struct device
*dev
, void *data
))
2230 struct klist_iter i
;
2231 struct device
*child
;
2236 klist_iter_init(&parent
->p
->klist_children
, &i
);
2237 while ((child
= next_device(&i
)))
2238 if (match(child
, data
) && get_device(child
))
2240 klist_iter_exit(&i
);
2243 EXPORT_SYMBOL_GPL(device_find_child
);
2245 int __init
devices_init(void)
2247 devices_kset
= kset_create_and_add("devices", &device_uevent_ops
, NULL
);
2250 dev_kobj
= kobject_create_and_add("dev", NULL
);
2253 sysfs_dev_block_kobj
= kobject_create_and_add("block", dev_kobj
);
2254 if (!sysfs_dev_block_kobj
)
2255 goto block_kobj_err
;
2256 sysfs_dev_char_kobj
= kobject_create_and_add("char", dev_kobj
);
2257 if (!sysfs_dev_char_kobj
)
2263 kobject_put(sysfs_dev_block_kobj
);
2265 kobject_put(dev_kobj
);
2267 kset_unregister(devices_kset
);
2271 static int device_check_offline(struct device
*dev
, void *not_used
)
2275 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2279 return device_supports_offline(dev
) && !dev
->offline
? -EBUSY
: 0;
2283 * device_offline - Prepare the device for hot-removal.
2284 * @dev: Device to be put offline.
2286 * Execute the device bus type's .offline() callback, if present, to prepare
2287 * the device for a subsequent hot-removal. If that succeeds, the device must
2288 * not be used until either it is removed or its bus type's .online() callback
2291 * Call under device_hotplug_lock.
2293 int device_offline(struct device
*dev
)
2297 if (dev
->offline_disabled
)
2300 ret
= device_for_each_child(dev
, NULL
, device_check_offline
);
2305 if (device_supports_offline(dev
)) {
2309 ret
= dev
->bus
->offline(dev
);
2311 kobject_uevent(&dev
->kobj
, KOBJ_OFFLINE
);
2312 dev
->offline
= true;
2322 * device_online - Put the device back online after successful device_offline().
2323 * @dev: Device to be put back online.
2325 * If device_offline() has been successfully executed for @dev, but the device
2326 * has not been removed subsequently, execute its bus type's .online() callback
2327 * to indicate that the device can be used again.
2329 * Call under device_hotplug_lock.
2331 int device_online(struct device
*dev
)
2336 if (device_supports_offline(dev
)) {
2338 ret
= dev
->bus
->online(dev
);
2340 kobject_uevent(&dev
->kobj
, KOBJ_ONLINE
);
2341 dev
->offline
= false;
2352 struct root_device
{
2354 struct module
*owner
;
2357 static inline struct root_device
*to_root_device(struct device
*d
)
2359 return container_of(d
, struct root_device
, dev
);
2362 static void root_device_release(struct device
*dev
)
2364 kfree(to_root_device(dev
));
2368 * __root_device_register - allocate and register a root device
2369 * @name: root device name
2370 * @owner: owner module of the root device, usually THIS_MODULE
2372 * This function allocates a root device and registers it
2373 * using device_register(). In order to free the returned
2374 * device, use root_device_unregister().
2376 * Root devices are dummy devices which allow other devices
2377 * to be grouped under /sys/devices. Use this function to
2378 * allocate a root device and then use it as the parent of
2379 * any device which should appear under /sys/devices/{name}
2381 * The /sys/devices/{name} directory will also contain a
2382 * 'module' symlink which points to the @owner directory
2385 * Returns &struct device pointer on success, or ERR_PTR() on error.
2387 * Note: You probably want to use root_device_register().
2389 struct device
*__root_device_register(const char *name
, struct module
*owner
)
2391 struct root_device
*root
;
2394 root
= kzalloc(sizeof(struct root_device
), GFP_KERNEL
);
2396 return ERR_PTR(err
);
2398 err
= dev_set_name(&root
->dev
, "%s", name
);
2401 return ERR_PTR(err
);
2404 root
->dev
.release
= root_device_release
;
2406 err
= device_register(&root
->dev
);
2408 put_device(&root
->dev
);
2409 return ERR_PTR(err
);
2412 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
2414 struct module_kobject
*mk
= &owner
->mkobj
;
2416 err
= sysfs_create_link(&root
->dev
.kobj
, &mk
->kobj
, "module");
2418 device_unregister(&root
->dev
);
2419 return ERR_PTR(err
);
2421 root
->owner
= owner
;
2427 EXPORT_SYMBOL_GPL(__root_device_register
);
2430 * root_device_unregister - unregister and free a root device
2431 * @dev: device going away
2433 * This function unregisters and cleans up a device that was created by
2434 * root_device_register().
2436 void root_device_unregister(struct device
*dev
)
2438 struct root_device
*root
= to_root_device(dev
);
2441 sysfs_remove_link(&root
->dev
.kobj
, "module");
2443 device_unregister(dev
);
2445 EXPORT_SYMBOL_GPL(root_device_unregister
);
2448 static void device_create_release(struct device
*dev
)
2450 pr_debug("device: '%s': %s\n", dev_name(dev
), __func__
);
2454 static struct device
*
2455 device_create_groups_vargs(struct class *class, struct device
*parent
,
2456 dev_t devt
, void *drvdata
,
2457 const struct attribute_group
**groups
,
2458 const char *fmt
, va_list args
)
2460 struct device
*dev
= NULL
;
2461 int retval
= -ENODEV
;
2463 if (class == NULL
|| IS_ERR(class))
2466 dev
= kzalloc(sizeof(*dev
), GFP_KERNEL
);
2472 device_initialize(dev
);
2475 dev
->parent
= parent
;
2476 dev
->groups
= groups
;
2477 dev
->release
= device_create_release
;
2478 dev_set_drvdata(dev
, drvdata
);
2480 retval
= kobject_set_name_vargs(&dev
->kobj
, fmt
, args
);
2484 retval
= device_add(dev
);
2492 return ERR_PTR(retval
);
2496 * device_create_vargs - creates a device and registers it with sysfs
2497 * @class: pointer to the struct class that this device should be registered to
2498 * @parent: pointer to the parent struct device of this new device, if any
2499 * @devt: the dev_t for the char device to be added
2500 * @drvdata: the data to be added to the device for callbacks
2501 * @fmt: string for the device's name
2502 * @args: va_list for the device's name
2504 * This function can be used by char device classes. A struct device
2505 * will be created in sysfs, registered to the specified class.
2507 * A "dev" file will be created, showing the dev_t for the device, if
2508 * the dev_t is not 0,0.
2509 * If a pointer to a parent struct device is passed in, the newly created
2510 * struct device will be a child of that device in sysfs.
2511 * The pointer to the struct device will be returned from the call.
2512 * Any further sysfs files that might be required can be created using this
2515 * Returns &struct device pointer on success, or ERR_PTR() on error.
2517 * Note: the struct class passed to this function must have previously
2518 * been created with a call to class_create().
2520 struct device
*device_create_vargs(struct class *class, struct device
*parent
,
2521 dev_t devt
, void *drvdata
, const char *fmt
,
2524 return device_create_groups_vargs(class, parent
, devt
, drvdata
, NULL
,
2527 EXPORT_SYMBOL_GPL(device_create_vargs
);
2530 * device_create - creates a device and registers it with sysfs
2531 * @class: pointer to the struct class that this device should be registered to
2532 * @parent: pointer to the parent struct device of this new device, if any
2533 * @devt: the dev_t for the char device to be added
2534 * @drvdata: the data to be added to the device for callbacks
2535 * @fmt: string for the device's name
2537 * This function can be used by char device classes. A struct device
2538 * will be created in sysfs, registered to the specified class.
2540 * A "dev" file will be created, showing the dev_t for the device, if
2541 * the dev_t is not 0,0.
2542 * If a pointer to a parent struct device is passed in, the newly created
2543 * struct device will be a child of that device in sysfs.
2544 * The pointer to the struct device will be returned from the call.
2545 * Any further sysfs files that might be required can be created using this
2548 * Returns &struct device pointer on success, or ERR_PTR() on error.
2550 * Note: the struct class passed to this function must have previously
2551 * been created with a call to class_create().
2553 struct device
*device_create(struct class *class, struct device
*parent
,
2554 dev_t devt
, void *drvdata
, const char *fmt
, ...)
2559 va_start(vargs
, fmt
);
2560 dev
= device_create_vargs(class, parent
, devt
, drvdata
, fmt
, vargs
);
2564 EXPORT_SYMBOL_GPL(device_create
);
2567 * device_create_with_groups - creates a device and registers it with sysfs
2568 * @class: pointer to the struct class that this device should be registered to
2569 * @parent: pointer to the parent struct device of this new device, if any
2570 * @devt: the dev_t for the char device to be added
2571 * @drvdata: the data to be added to the device for callbacks
2572 * @groups: NULL-terminated list of attribute groups to be created
2573 * @fmt: string for the device's name
2575 * This function can be used by char device classes. A struct device
2576 * will be created in sysfs, registered to the specified class.
2577 * Additional attributes specified in the groups parameter will also
2578 * be created automatically.
2580 * A "dev" file will be created, showing the dev_t for the device, if
2581 * the dev_t is not 0,0.
2582 * If a pointer to a parent struct device is passed in, the newly created
2583 * struct device will be a child of that device in sysfs.
2584 * The pointer to the struct device will be returned from the call.
2585 * Any further sysfs files that might be required can be created using this
2588 * Returns &struct device pointer on success, or ERR_PTR() on error.
2590 * Note: the struct class passed to this function must have previously
2591 * been created with a call to class_create().
2593 struct device
*device_create_with_groups(struct class *class,
2594 struct device
*parent
, dev_t devt
,
2596 const struct attribute_group
**groups
,
2597 const char *fmt
, ...)
2602 va_start(vargs
, fmt
);
2603 dev
= device_create_groups_vargs(class, parent
, devt
, drvdata
, groups
,
2608 EXPORT_SYMBOL_GPL(device_create_with_groups
);
2610 static int __match_devt(struct device
*dev
, const void *data
)
2612 const dev_t
*devt
= data
;
2614 return dev
->devt
== *devt
;
2618 * device_destroy - removes a device that was created with device_create()
2619 * @class: pointer to the struct class that this device was registered with
2620 * @devt: the dev_t of the device that was previously registered
2622 * This call unregisters and cleans up a device that was created with a
2623 * call to device_create().
2625 void device_destroy(struct class *class, dev_t devt
)
2629 dev
= class_find_device(class, NULL
, &devt
, __match_devt
);
2632 device_unregister(dev
);
2635 EXPORT_SYMBOL_GPL(device_destroy
);
2638 * device_rename - renames a device
2639 * @dev: the pointer to the struct device to be renamed
2640 * @new_name: the new name of the device
2642 * It is the responsibility of the caller to provide mutual
2643 * exclusion between two different calls of device_rename
2644 * on the same device to ensure that new_name is valid and
2645 * won't conflict with other devices.
2647 * Note: Don't call this function. Currently, the networking layer calls this
2648 * function, but that will change. The following text from Kay Sievers offers
2651 * Renaming devices is racy at many levels, symlinks and other stuff are not
2652 * replaced atomically, and you get a "move" uevent, but it's not easy to
2653 * connect the event to the old and new device. Device nodes are not renamed at
2654 * all, there isn't even support for that in the kernel now.
2656 * In the meantime, during renaming, your target name might be taken by another
2657 * driver, creating conflicts. Or the old name is taken directly after you
2658 * renamed it -- then you get events for the same DEVPATH, before you even see
2659 * the "move" event. It's just a mess, and nothing new should ever rely on
2660 * kernel device renaming. Besides that, it's not even implemented now for
2661 * other things than (driver-core wise very simple) network devices.
2663 * We are currently about to change network renaming in udev to completely
2664 * disallow renaming of devices in the same namespace as the kernel uses,
2665 * because we can't solve the problems properly, that arise with swapping names
2666 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
2667 * be allowed to some other name than eth[0-9]*, for the aforementioned
2670 * Make up a "real" name in the driver before you register anything, or add
2671 * some other attributes for userspace to find the device, or use udev to add
2672 * symlinks -- but never rename kernel devices later, it's a complete mess. We
2673 * don't even want to get into that and try to implement the missing pieces in
2674 * the core. We really have other pieces to fix in the driver core mess. :)
2676 int device_rename(struct device
*dev
, const char *new_name
)
2678 struct kobject
*kobj
= &dev
->kobj
;
2679 char *old_device_name
= NULL
;
2682 dev
= get_device(dev
);
2686 dev_dbg(dev
, "renaming to %s\n", new_name
);
2688 old_device_name
= kstrdup(dev_name(dev
), GFP_KERNEL
);
2689 if (!old_device_name
) {
2695 error
= sysfs_rename_link_ns(&dev
->class->p
->subsys
.kobj
,
2696 kobj
, old_device_name
,
2697 new_name
, kobject_namespace(kobj
));
2702 error
= kobject_rename(kobj
, new_name
);
2709 kfree(old_device_name
);
2713 EXPORT_SYMBOL_GPL(device_rename
);
2715 static int device_move_class_links(struct device
*dev
,
2716 struct device
*old_parent
,
2717 struct device
*new_parent
)
2722 sysfs_remove_link(&dev
->kobj
, "device");
2724 error
= sysfs_create_link(&dev
->kobj
, &new_parent
->kobj
,
2730 * device_move - moves a device to a new parent
2731 * @dev: the pointer to the struct device to be moved
2732 * @new_parent: the new parent of the device (can by NULL)
2733 * @dpm_order: how to reorder the dpm_list
2735 int device_move(struct device
*dev
, struct device
*new_parent
,
2736 enum dpm_order dpm_order
)
2739 struct device
*old_parent
;
2740 struct kobject
*new_parent_kobj
;
2742 dev
= get_device(dev
);
2747 new_parent
= get_device(new_parent
);
2748 new_parent_kobj
= get_device_parent(dev
, new_parent
);
2749 if (IS_ERR(new_parent_kobj
)) {
2750 error
= PTR_ERR(new_parent_kobj
);
2751 put_device(new_parent
);
2755 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev
),
2756 __func__
, new_parent
? dev_name(new_parent
) : "<NULL>");
2757 error
= kobject_move(&dev
->kobj
, new_parent_kobj
);
2759 cleanup_glue_dir(dev
, new_parent_kobj
);
2760 put_device(new_parent
);
2763 old_parent
= dev
->parent
;
2764 dev
->parent
= new_parent
;
2766 klist_remove(&dev
->p
->knode_parent
);
2768 klist_add_tail(&dev
->p
->knode_parent
,
2769 &new_parent
->p
->klist_children
);
2770 set_dev_node(dev
, dev_to_node(new_parent
));
2774 error
= device_move_class_links(dev
, old_parent
, new_parent
);
2776 /* We ignore errors on cleanup since we're hosed anyway... */
2777 device_move_class_links(dev
, new_parent
, old_parent
);
2778 if (!kobject_move(&dev
->kobj
, &old_parent
->kobj
)) {
2780 klist_remove(&dev
->p
->knode_parent
);
2781 dev
->parent
= old_parent
;
2783 klist_add_tail(&dev
->p
->knode_parent
,
2784 &old_parent
->p
->klist_children
);
2785 set_dev_node(dev
, dev_to_node(old_parent
));
2788 cleanup_glue_dir(dev
, new_parent_kobj
);
2789 put_device(new_parent
);
2793 switch (dpm_order
) {
2794 case DPM_ORDER_NONE
:
2796 case DPM_ORDER_DEV_AFTER_PARENT
:
2797 device_pm_move_after(dev
, new_parent
);
2798 devices_kset_move_after(dev
, new_parent
);
2800 case DPM_ORDER_PARENT_BEFORE_DEV
:
2801 device_pm_move_before(new_parent
, dev
);
2802 devices_kset_move_before(new_parent
, dev
);
2804 case DPM_ORDER_DEV_LAST
:
2805 device_pm_move_last(dev
);
2806 devices_kset_move_last(dev
);
2810 put_device(old_parent
);
2816 EXPORT_SYMBOL_GPL(device_move
);
2819 * device_shutdown - call ->shutdown() on each device to shutdown.
2821 void device_shutdown(void)
2823 struct device
*dev
, *parent
;
2825 wait_for_device_probe();
2826 device_block_probing();
2828 spin_lock(&devices_kset
->list_lock
);
2830 * Walk the devices list backward, shutting down each in turn.
2831 * Beware that device unplug events may also start pulling
2832 * devices offline, even as the system is shutting down.
2834 while (!list_empty(&devices_kset
->list
)) {
2835 dev
= list_entry(devices_kset
->list
.prev
, struct device
,
2839 * hold reference count of device's parent to
2840 * prevent it from being freed because parent's
2841 * lock is to be held
2843 parent
= get_device(dev
->parent
);
2846 * Make sure the device is off the kset list, in the
2847 * event that dev->*->shutdown() doesn't remove it.
2849 list_del_init(&dev
->kobj
.entry
);
2850 spin_unlock(&devices_kset
->list_lock
);
2852 /* hold lock to avoid race with probe/release */
2854 device_lock(parent
);
2857 /* Don't allow any more runtime suspends */
2858 pm_runtime_get_noresume(dev
);
2859 pm_runtime_barrier(dev
);
2861 if (dev
->class && dev
->class->shutdown_pre
) {
2863 dev_info(dev
, "shutdown_pre\n");
2864 dev
->class->shutdown_pre(dev
);
2866 if (dev
->bus
&& dev
->bus
->shutdown
) {
2868 dev_info(dev
, "shutdown\n");
2869 dev
->bus
->shutdown(dev
);
2870 } else if (dev
->driver
&& dev
->driver
->shutdown
) {
2872 dev_info(dev
, "shutdown\n");
2873 dev
->driver
->shutdown(dev
);
2878 device_unlock(parent
);
2883 spin_lock(&devices_kset
->list_lock
);
2885 spin_unlock(&devices_kset
->list_lock
);
2889 * Device logging functions
2892 #ifdef CONFIG_PRINTK
2894 create_syslog_header(const struct device
*dev
, char *hdr
, size_t hdrlen
)
2900 subsys
= dev
->class->name
;
2902 subsys
= dev
->bus
->name
;
2906 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
, "SUBSYSTEM=%s", subsys
);
2911 * Add device identifier DEVICE=:
2915 * +sound:card0 subsystem:devname
2917 if (MAJOR(dev
->devt
)) {
2920 if (strcmp(subsys
, "block") == 0)
2925 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2927 c
, MAJOR(dev
->devt
), MINOR(dev
->devt
));
2928 } else if (strcmp(subsys
, "net") == 0) {
2929 struct net_device
*net
= to_net_dev(dev
);
2932 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2933 "DEVICE=n%u", net
->ifindex
);
2936 pos
+= snprintf(hdr
+ pos
, hdrlen
- pos
,
2937 "DEVICE=+%s:%s", subsys
, dev_name(dev
));
2946 dev_WARN(dev
, "device/subsystem name too long");
2950 int dev_vprintk_emit(int level
, const struct device
*dev
,
2951 const char *fmt
, va_list args
)
2956 hdrlen
= create_syslog_header(dev
, hdr
, sizeof(hdr
));
2958 return vprintk_emit(0, level
, hdrlen
? hdr
: NULL
, hdrlen
, fmt
, args
);
2960 EXPORT_SYMBOL(dev_vprintk_emit
);
2962 int dev_printk_emit(int level
, const struct device
*dev
, const char *fmt
, ...)
2967 va_start(args
, fmt
);
2969 r
= dev_vprintk_emit(level
, dev
, fmt
, args
);
2975 EXPORT_SYMBOL(dev_printk_emit
);
2977 static void __dev_printk(const char *level
, const struct device
*dev
,
2978 struct va_format
*vaf
)
2981 dev_printk_emit(level
[1] - '0', dev
, "%s %s: %pV",
2982 dev_driver_string(dev
), dev_name(dev
), vaf
);
2984 printk("%s(NULL device *): %pV", level
, vaf
);
2987 void dev_printk(const char *level
, const struct device
*dev
,
2988 const char *fmt
, ...)
2990 struct va_format vaf
;
2993 va_start(args
, fmt
);
2998 __dev_printk(level
, dev
, &vaf
);
3002 EXPORT_SYMBOL(dev_printk
);
3004 #define define_dev_printk_level(func, kern_level) \
3005 void func(const struct device *dev, const char *fmt, ...) \
3007 struct va_format vaf; \
3010 va_start(args, fmt); \
3015 __dev_printk(kern_level, dev, &vaf); \
3019 EXPORT_SYMBOL(func);
3021 define_dev_printk_level(dev_emerg
, KERN_EMERG
);
3022 define_dev_printk_level(dev_alert
, KERN_ALERT
);
3023 define_dev_printk_level(dev_crit
, KERN_CRIT
);
3024 define_dev_printk_level(dev_err
, KERN_ERR
);
3025 define_dev_printk_level(dev_warn
, KERN_WARNING
);
3026 define_dev_printk_level(dev_notice
, KERN_NOTICE
);
3027 define_dev_printk_level(_dev_info
, KERN_INFO
);
3031 static inline bool fwnode_is_primary(struct fwnode_handle
*fwnode
)
3033 return fwnode
&& !IS_ERR(fwnode
->secondary
);
3037 * set_primary_fwnode - Change the primary firmware node of a given device.
3038 * @dev: Device to handle.
3039 * @fwnode: New primary firmware node of the device.
3041 * Set the device's firmware node pointer to @fwnode, but if a secondary
3042 * firmware node of the device is present, preserve it.
3044 void set_primary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
3047 struct fwnode_handle
*fn
= dev
->fwnode
;
3049 if (fwnode_is_primary(fn
))
3053 WARN_ON(fwnode
->secondary
);
3054 fwnode
->secondary
= fn
;
3056 dev
->fwnode
= fwnode
;
3058 dev
->fwnode
= fwnode_is_primary(dev
->fwnode
) ?
3059 dev
->fwnode
->secondary
: NULL
;
3062 EXPORT_SYMBOL_GPL(set_primary_fwnode
);
3065 * set_secondary_fwnode - Change the secondary firmware node of a given device.
3066 * @dev: Device to handle.
3067 * @fwnode: New secondary firmware node of the device.
3069 * If a primary firmware node of the device is present, set its secondary
3070 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
3073 void set_secondary_fwnode(struct device
*dev
, struct fwnode_handle
*fwnode
)
3076 fwnode
->secondary
= ERR_PTR(-ENODEV
);
3078 if (fwnode_is_primary(dev
->fwnode
))
3079 dev
->fwnode
->secondary
= fwnode
;
3081 dev
->fwnode
= fwnode
;
3085 * device_set_of_node_from_dev - reuse device-tree node of another device
3086 * @dev: device whose device-tree node is being set
3087 * @dev2: device whose device-tree node is being reused
3089 * Takes another reference to the new device-tree node after first dropping
3090 * any reference held to the old node.
3092 void device_set_of_node_from_dev(struct device
*dev
, const struct device
*dev2
)
3094 of_node_put(dev
->of_node
);
3095 dev
->of_node
= of_node_get(dev2
->of_node
);
3096 dev
->of_node_reused
= true;
3098 EXPORT_SYMBOL_GPL(device_set_of_node_from_dev
);