1 // SPDX-License-Identifier: GPL-2.0
3 * drivers/base/core.c - core driver model code (device registration, etc)
5 * Copyright (c) 2002-3 Patrick Mochel
6 * Copyright (c) 2002-3 Open Source Development Labs
7 * Copyright (c) 2006 Greg Kroah-Hartman <gregkh@suse.de>
8 * Copyright (c) 2006 Novell, Inc.
11 #include <linux/acpi.h>
12 #include <linux/cpufreq.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/fwnode.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/string.h>
20 #include <linux/kdev_t.h>
21 #include <linux/notifier.h>
23 #include <linux/of_device.h>
24 #include <linux/genhd.h>
25 #include <linux/mutex.h>
26 #include <linux/pm_runtime.h>
27 #include <linux/netdevice.h>
28 #include <linux/sched/signal.h>
29 #include <linux/sched/mm.h>
30 #include <linux/sysfs.h>
31 #include <linux/dma-map-ops.h> /* for dma_default_coherent */
34 #include "power/power.h"
36 #ifdef CONFIG_SYSFS_DEPRECATED
37 #ifdef CONFIG_SYSFS_DEPRECATED_V2
38 long sysfs_deprecated = 1;
40 long sysfs_deprecated = 0;
42 static int __init sysfs_deprecated_setup(char *arg)
44 return kstrtol(arg, 10, &sysfs_deprecated);
46 early_param("sysfs.deprecated", sysfs_deprecated_setup);
49 /* Device links support. */
50 static LIST_HEAD(deferred_sync);
51 static unsigned int defer_sync_state_count = 1;
52 static DEFINE_MUTEX(fwnode_link_lock);
53 static bool fw_devlink_is_permissive(void);
56 * fwnode_link_add - Create a link between two fwnode_handles.
57 * @con: Consumer end of the link.
58 * @sup: Supplier end of the link.
60 * Create a fwnode link between fwnode handles @con and @sup. The fwnode link
61 * represents the detail that the firmware lists @sup fwnode as supplying a
64 * The driver core will use the fwnode link to create a device link between the
65 * two device objects corresponding to @con and @sup when they are created. The
66 * driver core will automatically delete the fwnode link between @con and @sup
69 * Attempts to create duplicate links between the same pair of fwnode handles
70 * are ignored and there is no reference counting.
72 int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
74 struct fwnode_link *link;
77 mutex_lock(&fwnode_link_lock);
79 list_for_each_entry(link, &sup->consumers, s_hook)
80 if (link->consumer == con)
83 link = kzalloc(sizeof(*link), GFP_KERNEL);
90 INIT_LIST_HEAD(&link->s_hook);
92 INIT_LIST_HEAD(&link->c_hook);
94 list_add(&link->s_hook, &sup->consumers);
95 list_add(&link->c_hook, &con->suppliers);
97 mutex_unlock(&fwnode_link_lock);
103 * fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle.
104 * @fwnode: fwnode whose supplier links need to be deleted
106 * Deletes all supplier links connecting directly to @fwnode.
108 static void fwnode_links_purge_suppliers(struct fwnode_handle *fwnode)
110 struct fwnode_link *link, *tmp;
112 mutex_lock(&fwnode_link_lock);
113 list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
114 list_del(&link->s_hook);
115 list_del(&link->c_hook);
118 mutex_unlock(&fwnode_link_lock);
122 * fwnode_links_purge_consumers - Delete all consumer links of fwnode_handle.
123 * @fwnode: fwnode whose consumer links need to be deleted
125 * Deletes all consumer links connecting directly to @fwnode.
127 static void fwnode_links_purge_consumers(struct fwnode_handle *fwnode)
129 struct fwnode_link *link, *tmp;
131 mutex_lock(&fwnode_link_lock);
132 list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
133 list_del(&link->s_hook);
134 list_del(&link->c_hook);
137 mutex_unlock(&fwnode_link_lock);
141 * fwnode_links_purge - Delete all links connected to a fwnode_handle.
142 * @fwnode: fwnode whose links needs to be deleted
144 * Deletes all links connecting directly to a fwnode.
146 void fwnode_links_purge(struct fwnode_handle *fwnode)
148 fwnode_links_purge_suppliers(fwnode);
149 fwnode_links_purge_consumers(fwnode);
152 static void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
154 struct fwnode_handle *child;
156 /* Don't purge consumer links of an added child */
160 fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
161 fwnode_links_purge_consumers(fwnode);
163 fwnode_for_each_available_child_node(fwnode, child)
164 fw_devlink_purge_absent_suppliers(child);
168 static DEFINE_MUTEX(device_links_lock);
169 DEFINE_STATIC_SRCU(device_links_srcu);
171 static inline void device_links_write_lock(void)
173 mutex_lock(&device_links_lock);
176 static inline void device_links_write_unlock(void)
178 mutex_unlock(&device_links_lock);
181 int device_links_read_lock(void) __acquires(&device_links_srcu)
183 return srcu_read_lock(&device_links_srcu);
186 void device_links_read_unlock(int idx) __releases(&device_links_srcu)
188 srcu_read_unlock(&device_links_srcu, idx);
191 int device_links_read_lock_held(void)
193 return srcu_read_lock_held(&device_links_srcu);
195 #else /* !CONFIG_SRCU */
196 static DECLARE_RWSEM(device_links_lock);
198 static inline void device_links_write_lock(void)
200 down_write(&device_links_lock);
203 static inline void device_links_write_unlock(void)
205 up_write(&device_links_lock);
208 int device_links_read_lock(void)
210 down_read(&device_links_lock);
214 void device_links_read_unlock(int not_used)
216 up_read(&device_links_lock);
219 #ifdef CONFIG_DEBUG_LOCK_ALLOC
220 int device_links_read_lock_held(void)
222 return lockdep_is_held(&device_links_lock);
225 #endif /* !CONFIG_SRCU */
227 static bool device_is_ancestor(struct device *dev, struct device *target)
229 while (target->parent) {
230 target = target->parent;
238 * device_is_dependent - Check if one device depends on another one
239 * @dev: Device to check dependencies for.
240 * @target: Device to check against.
242 * Check if @target depends on @dev or any device dependent on it (its child or
243 * its consumer etc). Return 1 if that is the case or 0 otherwise.
245 int device_is_dependent(struct device *dev, void *target)
247 struct device_link *link;
251 * The "ancestors" check is needed to catch the case when the target
252 * device has not been completely initialized yet and it is still
253 * missing from the list of children of its parent device.
255 if (dev == target || device_is_ancestor(dev, target))
258 ret = device_for_each_child(dev, target, device_is_dependent);
262 list_for_each_entry(link, &dev->links.consumers, s_node) {
263 if ((link->flags & ~DL_FLAG_INFERRED) ==
264 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
267 if (link->consumer == target)
270 ret = device_is_dependent(link->consumer, target);
277 static void device_link_init_status(struct device_link *link,
278 struct device *consumer,
279 struct device *supplier)
281 switch (supplier->links.status) {
283 switch (consumer->links.status) {
286 * A consumer driver can create a link to a supplier
287 * that has not completed its probing yet as long as it
288 * knows that the supplier is already functional (for
289 * example, it has just acquired some resources from the
292 link->status = DL_STATE_CONSUMER_PROBE;
295 link->status = DL_STATE_DORMANT;
299 case DL_DEV_DRIVER_BOUND:
300 switch (consumer->links.status) {
302 link->status = DL_STATE_CONSUMER_PROBE;
304 case DL_DEV_DRIVER_BOUND:
305 link->status = DL_STATE_ACTIVE;
308 link->status = DL_STATE_AVAILABLE;
312 case DL_DEV_UNBINDING:
313 link->status = DL_STATE_SUPPLIER_UNBIND;
316 link->status = DL_STATE_DORMANT;
321 static int device_reorder_to_tail(struct device *dev, void *not_used)
323 struct device_link *link;
326 * Devices that have not been registered yet will be put to the ends
327 * of the lists during the registration, so skip them here.
329 if (device_is_registered(dev))
330 devices_kset_move_last(dev);
332 if (device_pm_initialized(dev))
333 device_pm_move_last(dev);
335 device_for_each_child(dev, NULL, device_reorder_to_tail);
336 list_for_each_entry(link, &dev->links.consumers, s_node) {
337 if ((link->flags & ~DL_FLAG_INFERRED) ==
338 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
340 device_reorder_to_tail(link->consumer, NULL);
347 * device_pm_move_to_tail - Move set of devices to the end of device lists
348 * @dev: Device to move
350 * This is a device_reorder_to_tail() wrapper taking the requisite locks.
352 * It moves the @dev along with all of its children and all of its consumers
353 * to the ends of the device_kset and dpm_list, recursively.
355 void device_pm_move_to_tail(struct device *dev)
359 idx = device_links_read_lock();
361 device_reorder_to_tail(dev, NULL);
363 device_links_read_unlock(idx);
366 #define to_devlink(dev) container_of((dev), struct device_link, link_dev)
368 static ssize_t status_show(struct device *dev,
369 struct device_attribute *attr, char *buf)
373 switch (to_devlink(dev)->status) {
375 output = "not tracked";
377 case DL_STATE_DORMANT:
380 case DL_STATE_AVAILABLE:
381 output = "available";
383 case DL_STATE_CONSUMER_PROBE:
384 output = "consumer probing";
386 case DL_STATE_ACTIVE:
389 case DL_STATE_SUPPLIER_UNBIND:
390 output = "supplier unbinding";
397 return sysfs_emit(buf, "%s\n", output);
399 static DEVICE_ATTR_RO(status);
401 static ssize_t auto_remove_on_show(struct device *dev,
402 struct device_attribute *attr, char *buf)
404 struct device_link *link = to_devlink(dev);
407 if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
408 output = "supplier unbind";
409 else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
410 output = "consumer unbind";
414 return sysfs_emit(buf, "%s\n", output);
416 static DEVICE_ATTR_RO(auto_remove_on);
418 static ssize_t runtime_pm_show(struct device *dev,
419 struct device_attribute *attr, char *buf)
421 struct device_link *link = to_devlink(dev);
423 return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
425 static DEVICE_ATTR_RO(runtime_pm);
427 static ssize_t sync_state_only_show(struct device *dev,
428 struct device_attribute *attr, char *buf)
430 struct device_link *link = to_devlink(dev);
432 return sysfs_emit(buf, "%d\n",
433 !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
435 static DEVICE_ATTR_RO(sync_state_only);
437 static struct attribute *devlink_attrs[] = {
438 &dev_attr_status.attr,
439 &dev_attr_auto_remove_on.attr,
440 &dev_attr_runtime_pm.attr,
441 &dev_attr_sync_state_only.attr,
444 ATTRIBUTE_GROUPS(devlink);
446 static void device_link_free(struct device_link *link)
448 while (refcount_dec_not_one(&link->rpm_active))
449 pm_runtime_put(link->supplier);
451 put_device(link->consumer);
452 put_device(link->supplier);
457 static void __device_link_free_srcu(struct rcu_head *rhead)
459 device_link_free(container_of(rhead, struct device_link, rcu_head));
462 static void devlink_dev_release(struct device *dev)
464 struct device_link *link = to_devlink(dev);
466 call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
469 static void devlink_dev_release(struct device *dev)
471 device_link_free(to_devlink(dev));
475 static struct class devlink_class = {
477 .owner = THIS_MODULE,
478 .dev_groups = devlink_groups,
479 .dev_release = devlink_dev_release,
482 static int devlink_add_symlinks(struct device *dev,
483 struct class_interface *class_intf)
487 struct device_link *link = to_devlink(dev);
488 struct device *sup = link->supplier;
489 struct device *con = link->consumer;
492 len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
493 strlen(dev_bus_name(con)) + strlen(dev_name(con)));
495 len += strlen("supplier:") + 1;
496 buf = kzalloc(len, GFP_KERNEL);
500 ret = sysfs_create_link(&link->link_dev.kobj, &sup->kobj, "supplier");
504 ret = sysfs_create_link(&link->link_dev.kobj, &con->kobj, "consumer");
508 snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
509 ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf);
513 snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
514 ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf);
521 snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
522 sysfs_remove_link(&sup->kobj, buf);
524 sysfs_remove_link(&link->link_dev.kobj, "consumer");
526 sysfs_remove_link(&link->link_dev.kobj, "supplier");
532 static void devlink_remove_symlinks(struct device *dev,
533 struct class_interface *class_intf)
535 struct device_link *link = to_devlink(dev);
537 struct device *sup = link->supplier;
538 struct device *con = link->consumer;
541 sysfs_remove_link(&link->link_dev.kobj, "consumer");
542 sysfs_remove_link(&link->link_dev.kobj, "supplier");
544 len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
545 strlen(dev_bus_name(con)) + strlen(dev_name(con)));
547 len += strlen("supplier:") + 1;
548 buf = kzalloc(len, GFP_KERNEL);
550 WARN(1, "Unable to properly free device link symlinks!\n");
554 snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
555 sysfs_remove_link(&con->kobj, buf);
556 snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
557 sysfs_remove_link(&sup->kobj, buf);
561 static struct class_interface devlink_class_intf = {
562 .class = &devlink_class,
563 .add_dev = devlink_add_symlinks,
564 .remove_dev = devlink_remove_symlinks,
567 static int __init devlink_class_init(void)
571 ret = class_register(&devlink_class);
575 ret = class_interface_register(&devlink_class_intf);
577 class_unregister(&devlink_class);
581 postcore_initcall(devlink_class_init);
583 #define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
584 DL_FLAG_AUTOREMOVE_SUPPLIER | \
585 DL_FLAG_AUTOPROBE_CONSUMER | \
586 DL_FLAG_SYNC_STATE_ONLY | \
589 #define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
590 DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
593 * device_link_add - Create a link between two devices.
594 * @consumer: Consumer end of the link.
595 * @supplier: Supplier end of the link.
596 * @flags: Link flags.
598 * The caller is responsible for the proper synchronization of the link creation
599 * with runtime PM. First, setting the DL_FLAG_PM_RUNTIME flag will cause the
600 * runtime PM framework to take the link into account. Second, if the
601 * DL_FLAG_RPM_ACTIVE flag is set in addition to it, the supplier devices will
602 * be forced into the active meta state and reference-counted upon the creation
603 * of the link. If DL_FLAG_PM_RUNTIME is not set, DL_FLAG_RPM_ACTIVE will be
606 * If DL_FLAG_STATELESS is set in @flags, the caller of this function is
607 * expected to release the link returned by it directly with the help of either
608 * device_link_del() or device_link_remove().
610 * If that flag is not set, however, the caller of this function is handing the
611 * management of the link over to the driver core entirely and its return value
612 * can only be used to check whether or not the link is present. In that case,
613 * the DL_FLAG_AUTOREMOVE_CONSUMER and DL_FLAG_AUTOREMOVE_SUPPLIER device link
614 * flags can be used to indicate to the driver core when the link can be safely
615 * deleted. Namely, setting one of them in @flags indicates to the driver core
616 * that the link is not going to be used (by the given caller of this function)
617 * after unbinding the consumer or supplier driver, respectively, from its
618 * device, so the link can be deleted at that point. If none of them is set,
619 * the link will be maintained until one of the devices pointed to by it (either
620 * the consumer or the supplier) is unregistered.
622 * Also, if DL_FLAG_STATELESS, DL_FLAG_AUTOREMOVE_CONSUMER and
623 * DL_FLAG_AUTOREMOVE_SUPPLIER are not set in @flags (that is, a persistent
624 * managed device link is being added), the DL_FLAG_AUTOPROBE_CONSUMER flag can
625 * be used to request the driver core to automatically probe for a consumer
626 * driver after successfully binding a driver to the supplier device.
628 * The combination of DL_FLAG_STATELESS and one of DL_FLAG_AUTOREMOVE_CONSUMER,
629 * DL_FLAG_AUTOREMOVE_SUPPLIER, or DL_FLAG_AUTOPROBE_CONSUMER set in @flags at
630 * the same time is invalid and will cause NULL to be returned upfront.
631 * However, if a device link between the given @consumer and @supplier pair
632 * exists already when this function is called for them, the existing link will
633 * be returned regardless of its current type and status (the link's flags may
634 * be modified then). The caller of this function is then expected to treat
635 * the link as though it has just been created, so (in particular) if
636 * DL_FLAG_STATELESS was passed in @flags, the link needs to be released
637 * explicitly when not needed any more (as stated above).
639 * A side effect of the link creation is re-ordering of dpm_list and the
640 * devices_kset list by moving the consumer device and all devices depending
641 * on it to the ends of these lists (that does not happen to devices that have
642 * not been registered when this function is called).
644 * The supplier device is required to be registered when this function is called
645 * and NULL will be returned if that is not the case. The consumer device need
646 * not be registered, however.
648 struct device_link *device_link_add(struct device *consumer,
649 struct device *supplier, u32 flags)
651 struct device_link *link;
653 if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS ||
654 (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
655 (flags & DL_FLAG_SYNC_STATE_ONLY &&
656 (flags & ~DL_FLAG_INFERRED) != DL_FLAG_SYNC_STATE_ONLY) ||
657 (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
658 flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
659 DL_FLAG_AUTOREMOVE_SUPPLIER)))
662 if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) {
663 if (pm_runtime_get_sync(supplier) < 0) {
664 pm_runtime_put_noidle(supplier);
669 if (!(flags & DL_FLAG_STATELESS))
670 flags |= DL_FLAG_MANAGED;
672 device_links_write_lock();
676 * If the supplier has not been fully registered yet or there is a
677 * reverse (non-SYNC_STATE_ONLY) dependency between the consumer and
678 * the supplier already in the graph, return NULL. If the link is a
679 * SYNC_STATE_ONLY link, we don't check for reverse dependencies
680 * because it only affects sync_state() callbacks.
682 if (!device_pm_initialized(supplier)
683 || (!(flags & DL_FLAG_SYNC_STATE_ONLY) &&
684 device_is_dependent(consumer, supplier))) {
690 * SYNC_STATE_ONLY links are useless once a consumer device has probed.
691 * So, only create it if the consumer hasn't probed yet.
693 if (flags & DL_FLAG_SYNC_STATE_ONLY &&
694 consumer->links.status != DL_DEV_NO_DRIVER &&
695 consumer->links.status != DL_DEV_PROBING) {
701 * DL_FLAG_AUTOREMOVE_SUPPLIER indicates that the link will be needed
702 * longer than for DL_FLAG_AUTOREMOVE_CONSUMER and setting them both
703 * together doesn't make sense, so prefer DL_FLAG_AUTOREMOVE_SUPPLIER.
705 if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
706 flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
708 list_for_each_entry(link, &supplier->links.consumers, s_node) {
709 if (link->consumer != consumer)
712 if (link->flags & DL_FLAG_INFERRED &&
713 !(flags & DL_FLAG_INFERRED))
714 link->flags &= ~DL_FLAG_INFERRED;
716 if (flags & DL_FLAG_PM_RUNTIME) {
717 if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
718 pm_runtime_new_link(consumer);
719 link->flags |= DL_FLAG_PM_RUNTIME;
721 if (flags & DL_FLAG_RPM_ACTIVE)
722 refcount_inc(&link->rpm_active);
725 if (flags & DL_FLAG_STATELESS) {
726 kref_get(&link->kref);
727 if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
728 !(link->flags & DL_FLAG_STATELESS)) {
729 link->flags |= DL_FLAG_STATELESS;
732 link->flags |= DL_FLAG_STATELESS;
738 * If the life time of the link following from the new flags is
739 * longer than indicated by the flags of the existing link,
740 * update the existing link to stay around longer.
742 if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) {
743 if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
744 link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
745 link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
747 } else if (!(flags & DL_FLAG_AUTOREMOVE_CONSUMER)) {
748 link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER |
749 DL_FLAG_AUTOREMOVE_SUPPLIER);
751 if (!(link->flags & DL_FLAG_MANAGED)) {
752 kref_get(&link->kref);
753 link->flags |= DL_FLAG_MANAGED;
754 device_link_init_status(link, consumer, supplier);
756 if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
757 !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
758 link->flags &= ~DL_FLAG_SYNC_STATE_ONLY;
765 link = kzalloc(sizeof(*link), GFP_KERNEL);
769 refcount_set(&link->rpm_active, 1);
771 get_device(supplier);
772 link->supplier = supplier;
773 INIT_LIST_HEAD(&link->s_node);
774 get_device(consumer);
775 link->consumer = consumer;
776 INIT_LIST_HEAD(&link->c_node);
778 kref_init(&link->kref);
780 link->link_dev.class = &devlink_class;
781 device_set_pm_not_required(&link->link_dev);
782 dev_set_name(&link->link_dev, "%s:%s--%s:%s",
783 dev_bus_name(supplier), dev_name(supplier),
784 dev_bus_name(consumer), dev_name(consumer));
785 if (device_register(&link->link_dev)) {
786 put_device(consumer);
787 put_device(supplier);
793 if (flags & DL_FLAG_PM_RUNTIME) {
794 if (flags & DL_FLAG_RPM_ACTIVE)
795 refcount_inc(&link->rpm_active);
797 pm_runtime_new_link(consumer);
800 /* Determine the initial link state. */
801 if (flags & DL_FLAG_STATELESS)
802 link->status = DL_STATE_NONE;
804 device_link_init_status(link, consumer, supplier);
807 * Some callers expect the link creation during consumer driver probe to
808 * resume the supplier even without DL_FLAG_RPM_ACTIVE.
810 if (link->status == DL_STATE_CONSUMER_PROBE &&
811 flags & DL_FLAG_PM_RUNTIME)
812 pm_runtime_resume(supplier);
814 list_add_tail_rcu(&link->s_node, &supplier->links.consumers);
815 list_add_tail_rcu(&link->c_node, &consumer->links.suppliers);
817 if (flags & DL_FLAG_SYNC_STATE_ONLY) {
819 "Linked as a sync state only consumer to %s\n",
826 * Move the consumer and all of the devices depending on it to the end
827 * of dpm_list and the devices_kset list.
829 * It is necessary to hold dpm_list locked throughout all that or else
830 * we may end up suspending with a wrong ordering of it.
832 device_reorder_to_tail(consumer, NULL);
834 dev_dbg(consumer, "Linked as a consumer to %s\n", dev_name(supplier));
838 device_links_write_unlock();
840 if ((flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) && !link)
841 pm_runtime_put(supplier);
845 EXPORT_SYMBOL_GPL(device_link_add);
848 static void __device_link_del(struct kref *kref)
850 struct device_link *link = container_of(kref, struct device_link, kref);
852 dev_dbg(link->consumer, "Dropping the link to %s\n",
853 dev_name(link->supplier));
855 pm_runtime_drop_link(link);
857 list_del_rcu(&link->s_node);
858 list_del_rcu(&link->c_node);
859 device_unregister(&link->link_dev);
861 #else /* !CONFIG_SRCU */
862 static void __device_link_del(struct kref *kref)
864 struct device_link *link = container_of(kref, struct device_link, kref);
866 dev_info(link->consumer, "Dropping the link to %s\n",
867 dev_name(link->supplier));
869 pm_runtime_drop_link(link);
871 list_del(&link->s_node);
872 list_del(&link->c_node);
873 device_unregister(&link->link_dev);
875 #endif /* !CONFIG_SRCU */
877 static void device_link_put_kref(struct device_link *link)
879 if (link->flags & DL_FLAG_STATELESS)
880 kref_put(&link->kref, __device_link_del);
882 WARN(1, "Unable to drop a managed device link reference\n");
886 * device_link_del - Delete a stateless link between two devices.
887 * @link: Device link to delete.
889 * The caller must ensure proper synchronization of this function with runtime
890 * PM. If the link was added multiple times, it needs to be deleted as often.
891 * Care is required for hotplugged devices: Their links are purged on removal
892 * and calling device_link_del() is then no longer allowed.
894 void device_link_del(struct device_link *link)
896 device_links_write_lock();
897 device_link_put_kref(link);
898 device_links_write_unlock();
900 EXPORT_SYMBOL_GPL(device_link_del);
903 * device_link_remove - Delete a stateless link between two devices.
904 * @consumer: Consumer end of the link.
905 * @supplier: Supplier end of the link.
907 * The caller must ensure proper synchronization of this function with runtime
910 void device_link_remove(void *consumer, struct device *supplier)
912 struct device_link *link;
914 if (WARN_ON(consumer == supplier))
917 device_links_write_lock();
919 list_for_each_entry(link, &supplier->links.consumers, s_node) {
920 if (link->consumer == consumer) {
921 device_link_put_kref(link);
926 device_links_write_unlock();
928 EXPORT_SYMBOL_GPL(device_link_remove);
930 static void device_links_missing_supplier(struct device *dev)
932 struct device_link *link;
934 list_for_each_entry(link, &dev->links.suppliers, c_node) {
935 if (link->status != DL_STATE_CONSUMER_PROBE)
938 if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
939 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
941 WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
942 WRITE_ONCE(link->status, DL_STATE_DORMANT);
948 * device_links_check_suppliers - Check presence of supplier drivers.
949 * @dev: Consumer device.
951 * Check links from this device to any suppliers. Walk the list of the device's
952 * links to suppliers and see if all of them are available. If not, simply
953 * return -EPROBE_DEFER.
955 * We need to guarantee that the supplier will not go away after the check has
956 * been positive here. It only can go away in __device_release_driver() and
957 * that function checks the device's links to consumers. This means we need to
958 * mark the link as "consumer probe in progress" to make the supplier removal
959 * wait for us to complete (or bad things may happen).
961 * Links without the DL_FLAG_MANAGED flag set are ignored.
963 int device_links_check_suppliers(struct device *dev)
965 struct device_link *link;
969 * Device waiting for supplier to become available is not allowed to
972 mutex_lock(&fwnode_link_lock);
973 if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
974 !fw_devlink_is_permissive()) {
975 dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
976 list_first_entry(&dev->fwnode->suppliers,
979 mutex_unlock(&fwnode_link_lock);
980 return -EPROBE_DEFER;
982 mutex_unlock(&fwnode_link_lock);
984 device_links_write_lock();
986 list_for_each_entry(link, &dev->links.suppliers, c_node) {
987 if (!(link->flags & DL_FLAG_MANAGED))
990 if (link->status != DL_STATE_AVAILABLE &&
991 !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
992 device_links_missing_supplier(dev);
993 dev_dbg(dev, "probe deferral - supplier %s not ready\n",
994 dev_name(link->supplier));
998 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
1000 dev->links.status = DL_DEV_PROBING;
1002 device_links_write_unlock();
1007 * __device_links_queue_sync_state - Queue a device for sync_state() callback
1008 * @dev: Device to call sync_state() on
1009 * @list: List head to queue the @dev on
1011 * Queues a device for a sync_state() callback when the device links write lock
1012 * isn't held. This allows the sync_state() execution flow to use device links
1013 * APIs. The caller must ensure this function is called with
1014 * device_links_write_lock() held.
1016 * This function does a get_device() to make sure the device is not freed while
1019 * So the caller must also ensure that device_links_flush_sync_list() is called
1020 * as soon as the caller releases device_links_write_lock(). This is necessary
1021 * to make sure the sync_state() is called in a timely fashion and the
1022 * put_device() is called on this device.
1024 static void __device_links_queue_sync_state(struct device *dev,
1025 struct list_head *list)
1027 struct device_link *link;
1029 if (!dev_has_sync_state(dev))
1031 if (dev->state_synced)
1034 list_for_each_entry(link, &dev->links.consumers, s_node) {
1035 if (!(link->flags & DL_FLAG_MANAGED))
1037 if (link->status != DL_STATE_ACTIVE)
1042 * Set the flag here to avoid adding the same device to a list more
1043 * than once. This can happen if new consumers get added to the device
1044 * and probed before the list is flushed.
1046 dev->state_synced = true;
1048 if (WARN_ON(!list_empty(&dev->links.defer_sync)))
1052 list_add_tail(&dev->links.defer_sync, list);
1056 * device_links_flush_sync_list - Call sync_state() on a list of devices
1057 * @list: List of devices to call sync_state() on
1058 * @dont_lock_dev: Device for which lock is already held by the caller
1060 * Calls sync_state() on all the devices that have been queued for it. This
1061 * function is used in conjunction with __device_links_queue_sync_state(). The
1062 * @dont_lock_dev parameter is useful when this function is called from a
1063 * context where a device lock is already held.
1065 static void device_links_flush_sync_list(struct list_head *list,
1066 struct device *dont_lock_dev)
1068 struct device *dev, *tmp;
1070 list_for_each_entry_safe(dev, tmp, list, links.defer_sync) {
1071 list_del_init(&dev->links.defer_sync);
1073 if (dev != dont_lock_dev)
1076 if (dev->bus->sync_state)
1077 dev->bus->sync_state(dev);
1078 else if (dev->driver && dev->driver->sync_state)
1079 dev->driver->sync_state(dev);
1081 if (dev != dont_lock_dev)
1088 void device_links_supplier_sync_state_pause(void)
1090 device_links_write_lock();
1091 defer_sync_state_count++;
1092 device_links_write_unlock();
1095 void device_links_supplier_sync_state_resume(void)
1097 struct device *dev, *tmp;
1098 LIST_HEAD(sync_list);
1100 device_links_write_lock();
1101 if (!defer_sync_state_count) {
1102 WARN(true, "Unmatched sync_state pause/resume!");
1105 defer_sync_state_count--;
1106 if (defer_sync_state_count)
1109 list_for_each_entry_safe(dev, tmp, &deferred_sync, links.defer_sync) {
1111 * Delete from deferred_sync list before queuing it to
1112 * sync_list because defer_sync is used for both lists.
1114 list_del_init(&dev->links.defer_sync);
1115 __device_links_queue_sync_state(dev, &sync_list);
1118 device_links_write_unlock();
1120 device_links_flush_sync_list(&sync_list, NULL);
1123 static int sync_state_resume_initcall(void)
1125 device_links_supplier_sync_state_resume();
1128 late_initcall(sync_state_resume_initcall);
1130 static void __device_links_supplier_defer_sync(struct device *sup)
1132 if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup))
1133 list_add_tail(&sup->links.defer_sync, &deferred_sync);
1136 static void device_link_drop_managed(struct device_link *link)
1138 link->flags &= ~DL_FLAG_MANAGED;
1139 WRITE_ONCE(link->status, DL_STATE_NONE);
1140 kref_put(&link->kref, __device_link_del);
1143 static ssize_t waiting_for_supplier_show(struct device *dev,
1144 struct device_attribute *attr,
1150 val = !list_empty(&dev->fwnode->suppliers);
1152 return sysfs_emit(buf, "%u\n", val);
1154 static DEVICE_ATTR_RO(waiting_for_supplier);
1157 * device_links_force_bind - Prepares device to be force bound
1158 * @dev: Consumer device.
1160 * device_bind_driver() force binds a device to a driver without calling any
1161 * driver probe functions. So the consumer really isn't going to wait for any
1162 * supplier before it's bound to the driver. We still want the device link
1163 * states to be sensible when this happens.
1165 * In preparation for device_bind_driver(), this function goes through each
1166 * supplier device links and checks if the supplier is bound. If it is, then
1167 * the device link status is set to CONSUMER_PROBE. Otherwise, the device link
1168 * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored.
1170 void device_links_force_bind(struct device *dev)
1172 struct device_link *link, *ln;
1174 device_links_write_lock();
1176 list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
1177 if (!(link->flags & DL_FLAG_MANAGED))
1180 if (link->status != DL_STATE_AVAILABLE) {
1181 device_link_drop_managed(link);
1184 WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
1186 dev->links.status = DL_DEV_PROBING;
1188 device_links_write_unlock();
1192 * device_links_driver_bound - Update device links after probing its driver.
1193 * @dev: Device to update the links for.
1195 * The probe has been successful, so update links from this device to any
1196 * consumers by changing their status to "available".
1198 * Also change the status of @dev's links to suppliers to "active".
1200 * Links without the DL_FLAG_MANAGED flag set are ignored.
1202 void device_links_driver_bound(struct device *dev)
1204 struct device_link *link, *ln;
1205 LIST_HEAD(sync_list);
1208 * If a device binds successfully, it's expected to have created all
1209 * the device links it needs to or make new device links as it needs
1210 * them. So, fw_devlink no longer needs to create device links to any
1211 * of the device's suppliers.
1213 * Also, if a child firmware node of this bound device is not added as
1214 * a device by now, assume it is never going to be added and make sure
1215 * other devices don't defer probe indefinitely by waiting for such a
1218 if (dev->fwnode && dev->fwnode->dev == dev) {
1219 struct fwnode_handle *child;
1220 fwnode_links_purge_suppliers(dev->fwnode);
1221 fwnode_for_each_available_child_node(dev->fwnode, child)
1222 fw_devlink_purge_absent_suppliers(child);
1224 device_remove_file(dev, &dev_attr_waiting_for_supplier);
1226 device_links_write_lock();
1228 list_for_each_entry(link, &dev->links.consumers, s_node) {
1229 if (!(link->flags & DL_FLAG_MANAGED))
1233 * Links created during consumer probe may be in the "consumer
1234 * probe" state to start with if the supplier is still probing
1235 * when they are created and they may become "active" if the
1236 * consumer probe returns first. Skip them here.
1238 if (link->status == DL_STATE_CONSUMER_PROBE ||
1239 link->status == DL_STATE_ACTIVE)
1242 WARN_ON(link->status != DL_STATE_DORMANT);
1243 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
1245 if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
1246 driver_deferred_probe_add(link->consumer);
1249 if (defer_sync_state_count)
1250 __device_links_supplier_defer_sync(dev);
1252 __device_links_queue_sync_state(dev, &sync_list);
1254 list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
1255 struct device *supplier;
1257 if (!(link->flags & DL_FLAG_MANAGED))
1260 supplier = link->supplier;
1261 if (link->flags & DL_FLAG_SYNC_STATE_ONLY) {
1263 * When DL_FLAG_SYNC_STATE_ONLY is set, it means no
1264 * other DL_MANAGED_LINK_FLAGS have been set. So, it's
1265 * save to drop the managed link completely.
1267 device_link_drop_managed(link);
1269 WARN_ON(link->status != DL_STATE_CONSUMER_PROBE);
1270 WRITE_ONCE(link->status, DL_STATE_ACTIVE);
1274 * This needs to be done even for the deleted
1275 * DL_FLAG_SYNC_STATE_ONLY device link in case it was the last
1276 * device link that was preventing the supplier from getting a
1277 * sync_state() call.
1279 if (defer_sync_state_count)
1280 __device_links_supplier_defer_sync(supplier);
1282 __device_links_queue_sync_state(supplier, &sync_list);
1285 dev->links.status = DL_DEV_DRIVER_BOUND;
1287 device_links_write_unlock();
1289 device_links_flush_sync_list(&sync_list, dev);
1293 * __device_links_no_driver - Update links of a device without a driver.
1294 * @dev: Device without a drvier.
1296 * Delete all non-persistent links from this device to any suppliers.
1298 * Persistent links stay around, but their status is changed to "available",
1299 * unless they already are in the "supplier unbind in progress" state in which
1300 * case they need not be updated.
1302 * Links without the DL_FLAG_MANAGED flag set are ignored.
1304 static void __device_links_no_driver(struct device *dev)
1306 struct device_link *link, *ln;
1308 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
1309 if (!(link->flags & DL_FLAG_MANAGED))
1312 if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
1313 device_link_drop_managed(link);
1317 if (link->status != DL_STATE_CONSUMER_PROBE &&
1318 link->status != DL_STATE_ACTIVE)
1321 if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
1322 WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
1324 WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
1325 WRITE_ONCE(link->status, DL_STATE_DORMANT);
1329 dev->links.status = DL_DEV_NO_DRIVER;
1333 * device_links_no_driver - Update links after failing driver probe.
1334 * @dev: Device whose driver has just failed to probe.
1336 * Clean up leftover links to consumers for @dev and invoke
1337 * %__device_links_no_driver() to update links to suppliers for it as
1340 * Links without the DL_FLAG_MANAGED flag set are ignored.
1342 void device_links_no_driver(struct device *dev)
1344 struct device_link *link;
1346 device_links_write_lock();
1348 list_for_each_entry(link, &dev->links.consumers, s_node) {
1349 if (!(link->flags & DL_FLAG_MANAGED))
1353 * The probe has failed, so if the status of the link is
1354 * "consumer probe" or "active", it must have been added by
1355 * a probing consumer while this device was still probing.
1356 * Change its state to "dormant", as it represents a valid
1357 * relationship, but it is not functionally meaningful.
1359 if (link->status == DL_STATE_CONSUMER_PROBE ||
1360 link->status == DL_STATE_ACTIVE)
1361 WRITE_ONCE(link->status, DL_STATE_DORMANT);
1364 __device_links_no_driver(dev);
1366 device_links_write_unlock();
1370 * device_links_driver_cleanup - Update links after driver removal.
1371 * @dev: Device whose driver has just gone away.
1373 * Update links to consumers for @dev by changing their status to "dormant" and
1374 * invoke %__device_links_no_driver() to update links to suppliers for it as
1377 * Links without the DL_FLAG_MANAGED flag set are ignored.
1379 void device_links_driver_cleanup(struct device *dev)
1381 struct device_link *link, *ln;
1383 device_links_write_lock();
1385 list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) {
1386 if (!(link->flags & DL_FLAG_MANAGED))
1389 WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);
1390 WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
1393 * autoremove the links between this @dev and its consumer
1394 * devices that are not active, i.e. where the link state
1395 * has moved to DL_STATE_SUPPLIER_UNBIND.
1397 if (link->status == DL_STATE_SUPPLIER_UNBIND &&
1398 link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
1399 device_link_drop_managed(link);
1401 WRITE_ONCE(link->status, DL_STATE_DORMANT);
1404 list_del_init(&dev->links.defer_sync);
1405 __device_links_no_driver(dev);
1407 device_links_write_unlock();
1411 * device_links_busy - Check if there are any busy links to consumers.
1412 * @dev: Device to check.
1414 * Check each consumer of the device and return 'true' if its link's status
1415 * is one of "consumer probe" or "active" (meaning that the given consumer is
1416 * probing right now or its driver is present). Otherwise, change the link
1417 * state to "supplier unbind" to prevent the consumer from being probed
1418 * successfully going forward.
1420 * Return 'false' if there are no probing or active consumers.
1422 * Links without the DL_FLAG_MANAGED flag set are ignored.
1424 bool device_links_busy(struct device *dev)
1426 struct device_link *link;
1429 device_links_write_lock();
1431 list_for_each_entry(link, &dev->links.consumers, s_node) {
1432 if (!(link->flags & DL_FLAG_MANAGED))
1435 if (link->status == DL_STATE_CONSUMER_PROBE
1436 || link->status == DL_STATE_ACTIVE) {
1440 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
1443 dev->links.status = DL_DEV_UNBINDING;
1445 device_links_write_unlock();
1450 * device_links_unbind_consumers - Force unbind consumers of the given device.
1451 * @dev: Device to unbind the consumers of.
1453 * Walk the list of links to consumers for @dev and if any of them is in the
1454 * "consumer probe" state, wait for all device probes in progress to complete
1457 * If that's not the case, change the status of the link to "supplier unbind"
1458 * and check if the link was in the "active" state. If so, force the consumer
1459 * driver to unbind and start over (the consumer will not re-probe as we have
1460 * changed the state of the link already).
1462 * Links without the DL_FLAG_MANAGED flag set are ignored.
1464 void device_links_unbind_consumers(struct device *dev)
1466 struct device_link *link;
1469 device_links_write_lock();
1471 list_for_each_entry(link, &dev->links.consumers, s_node) {
1472 enum device_link_state status;
1474 if (!(link->flags & DL_FLAG_MANAGED) ||
1475 link->flags & DL_FLAG_SYNC_STATE_ONLY)
1478 status = link->status;
1479 if (status == DL_STATE_CONSUMER_PROBE) {
1480 device_links_write_unlock();
1482 wait_for_device_probe();
1485 WRITE_ONCE(link->status, DL_STATE_SUPPLIER_UNBIND);
1486 if (status == DL_STATE_ACTIVE) {
1487 struct device *consumer = link->consumer;
1489 get_device(consumer);
1491 device_links_write_unlock();
1493 device_release_driver_internal(consumer, NULL,
1495 put_device(consumer);
1500 device_links_write_unlock();
1504 * device_links_purge - Delete existing links to other devices.
1505 * @dev: Target device.
1507 static void device_links_purge(struct device *dev)
1509 struct device_link *link, *ln;
1511 if (dev->class == &devlink_class)
1515 * Delete all of the remaining links from this device to any other
1516 * devices (either consumers or suppliers).
1518 device_links_write_lock();
1520 list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
1521 WARN_ON(link->status == DL_STATE_ACTIVE);
1522 __device_link_del(&link->kref);
1525 list_for_each_entry_safe_reverse(link, ln, &dev->links.consumers, s_node) {
1526 WARN_ON(link->status != DL_STATE_DORMANT &&
1527 link->status != DL_STATE_NONE);
1528 __device_link_del(&link->kref);
1531 device_links_write_unlock();
1534 #define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \
1535 DL_FLAG_SYNC_STATE_ONLY)
1536 #define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \
1537 DL_FLAG_AUTOPROBE_CONSUMER)
1538 #define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \
1541 static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
1542 static int __init fw_devlink_setup(char *arg)
1547 if (strcmp(arg, "off") == 0) {
1548 fw_devlink_flags = 0;
1549 } else if (strcmp(arg, "permissive") == 0) {
1550 fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
1551 } else if (strcmp(arg, "on") == 0) {
1552 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
1553 } else if (strcmp(arg, "rpm") == 0) {
1554 fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
1558 early_param("fw_devlink", fw_devlink_setup);
1560 static bool fw_devlink_strict;
1561 static int __init fw_devlink_strict_setup(char *arg)
1563 return strtobool(arg, &fw_devlink_strict);
1565 early_param("fw_devlink.strict", fw_devlink_strict_setup);
1567 u32 fw_devlink_get_flags(void)
1569 return fw_devlink_flags;
1572 static bool fw_devlink_is_permissive(void)
1574 return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE;
1577 bool fw_devlink_is_strict(void)
1579 return fw_devlink_strict && !fw_devlink_is_permissive();
1582 static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
1584 if (fwnode->flags & FWNODE_FLAG_LINKS_ADDED)
1587 fwnode_call_int_op(fwnode, add_links);
1588 fwnode->flags |= FWNODE_FLAG_LINKS_ADDED;
1591 static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
1593 struct fwnode_handle *child = NULL;
1595 fw_devlink_parse_fwnode(fwnode);
1597 while ((child = fwnode_get_next_available_child_node(fwnode, child)))
1598 fw_devlink_parse_fwtree(child);
1602 * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
1603 * @con: Device to check dependencies for.
1604 * @sup: Device to check against.
1606 * Check if @sup depends on @con or any device dependent on it (its child or
1607 * its consumer etc). When such a cyclic dependency is found, convert all
1608 * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
1609 * This is the equivalent of doing fw_devlink=permissive just between the
1610 * devices in the cycle. We need to do this because, at this point, fw_devlink
1611 * can't tell which of these dependencies is not a real dependency.
1613 * Return 1 if a cycle is found. Otherwise, return 0.
1615 static int fw_devlink_relax_cycle(struct device *con, void *sup)
1617 struct device_link *link;
1623 ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
1627 list_for_each_entry(link, &con->links.consumers, s_node) {
1628 if ((link->flags & ~DL_FLAG_INFERRED) ==
1629 (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
1632 if (!fw_devlink_relax_cycle(link->consumer, sup))
1637 if (!(link->flags & DL_FLAG_INFERRED))
1640 pm_runtime_drop_link(link);
1641 link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
1642 dev_dbg(link->consumer, "Relaxing link with %s\n",
1643 dev_name(link->supplier));
1649 * fw_devlink_create_devlink - Create a device link from a consumer to fwnode
1650 * @con: consumer device for the device link
1651 * @sup_handle: fwnode handle of supplier
1652 * @flags: devlink flags
1654 * This function will try to create a device link between the consumer device
1655 * @con and the supplier device represented by @sup_handle.
1657 * The supplier has to be provided as a fwnode because incorrect cycles in
1658 * fwnode links can sometimes cause the supplier device to never be created.
1659 * This function detects such cases and returns an error if it cannot create a
1660 * device link from the consumer to a missing supplier.
1663 * 0 on successfully creating a device link
1664 * -EINVAL if the device link cannot be created as expected
1665 * -EAGAIN if the device link cannot be created right now, but it may be
1666 * possible to do that in the future
1668 static int fw_devlink_create_devlink(struct device *con,
1669 struct fwnode_handle *sup_handle, u32 flags)
1671 struct device *sup_dev;
1674 sup_dev = get_dev_from_fwnode(sup_handle);
1677 * If it's one of those drivers that don't actually bind to
1678 * their device using driver core, then don't wait on this
1679 * supplier device indefinitely.
1681 if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
1682 sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
1688 * If this fails, it is due to cycles in device links. Just
1689 * give up on this link and treat it as invalid.
1691 if (!device_link_add(con, sup_dev, flags) &&
1692 !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
1693 dev_info(con, "Fixing up cyclic dependency with %s\n",
1695 device_links_write_lock();
1696 fw_devlink_relax_cycle(con, sup_dev);
1697 device_links_write_unlock();
1698 device_link_add(con, sup_dev,
1699 FW_DEVLINK_FLAGS_PERMISSIVE);
1706 /* Supplier that's already initialized without a struct device. */
1707 if (sup_handle->flags & FWNODE_FLAG_INITIALIZED)
1711 * DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports
1712 * cycles. So cycle detection isn't necessary and shouldn't be
1715 if (flags & DL_FLAG_SYNC_STATE_ONLY)
1719 * If we can't find the supplier device from its fwnode, it might be
1720 * due to a cyclic dependency between fwnodes. Some of these cycles can
1721 * be broken by applying logic. Check for these types of cycles and
1722 * break them so that devices in the cycle probe properly.
1724 * If the supplier's parent is dependent on the consumer, then
1725 * the consumer-supplier dependency is a false dependency. So,
1726 * treat it as an invalid link.
1728 sup_dev = fwnode_get_next_parent_dev(sup_handle);
1729 if (sup_dev && device_is_dependent(con, sup_dev)) {
1730 dev_dbg(con, "Not linking to %pfwP - False link\n",
1735 * Can't check for cycles or no cycles. So let's try
1742 put_device(sup_dev);
1747 * __fw_devlink_link_to_consumers - Create device links to consumers of a device
1748 * @dev: Device that needs to be linked to its consumers
1750 * This function looks at all the consumer fwnodes of @dev and creates device
1751 * links between the consumer device and @dev (supplier).
1753 * If the consumer device has not been added yet, then this function creates a
1754 * SYNC_STATE_ONLY link between @dev (supplier) and the closest ancestor device
1755 * of the consumer fwnode. This is necessary to make sure @dev doesn't get a
1756 * sync_state() callback before the real consumer device gets to be added and
1759 * Once device links are created from the real consumer to @dev (supplier), the
1760 * fwnode links are deleted.
1762 static void __fw_devlink_link_to_consumers(struct device *dev)
1764 struct fwnode_handle *fwnode = dev->fwnode;
1765 struct fwnode_link *link, *tmp;
1767 list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
1768 u32 dl_flags = fw_devlink_get_flags();
1769 struct device *con_dev;
1770 bool own_link = true;
1773 con_dev = get_dev_from_fwnode(link->consumer);
1775 * If consumer device is not available yet, make a "proxy"
1776 * SYNC_STATE_ONLY link from the consumer's parent device to
1777 * the supplier device. This is necessary to make sure the
1778 * supplier doesn't get a sync_state() callback before the real
1779 * consumer can create a device link to the supplier.
1781 * This proxy link step is needed to handle the case where the
1782 * consumer's parent device is added before the supplier.
1785 con_dev = fwnode_get_next_parent_dev(link->consumer);
1787 * However, if the consumer's parent device is also the
1788 * parent of the supplier, don't create a
1789 * consumer-supplier link from the parent to its child
1790 * device. Such a dependency is impossible.
1793 fwnode_is_ancestor_of(con_dev->fwnode, fwnode)) {
1794 put_device(con_dev);
1798 dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
1805 ret = fw_devlink_create_devlink(con_dev, fwnode, dl_flags);
1806 put_device(con_dev);
1807 if (!own_link || ret == -EAGAIN)
1810 list_del(&link->s_hook);
1811 list_del(&link->c_hook);
1817 * __fw_devlink_link_to_suppliers - Create device links to suppliers of a device
1818 * @dev: The consumer device that needs to be linked to its suppliers
1819 * @fwnode: Root of the fwnode tree that is used to create device links
1821 * This function looks at all the supplier fwnodes of fwnode tree rooted at
1822 * @fwnode and creates device links between @dev (consumer) and all the
1823 * supplier devices of the entire fwnode tree at @fwnode.
1825 * The function creates normal (non-SYNC_STATE_ONLY) device links between @dev
1826 * and the real suppliers of @dev. Once these device links are created, the
1827 * fwnode links are deleted. When such device links are successfully created,
1828 * this function is called recursively on those supplier devices. This is
1829 * needed to detect and break some invalid cycles in fwnode links. See
1830 * fw_devlink_create_devlink() for more details.
1832 * In addition, it also looks at all the suppliers of the entire fwnode tree
1833 * because some of the child devices of @dev that have not been added yet
1834 * (because @dev hasn't probed) might already have their suppliers added to
1835 * driver core. So, this function creates SYNC_STATE_ONLY device links between
1836 * @dev (consumer) and these suppliers to make sure they don't execute their
1837 * sync_state() callbacks before these child devices have a chance to create
1838 * their device links. The fwnode links that correspond to the child devices
1839 * aren't delete because they are needed later to create the device links
1840 * between the real consumer and supplier devices.
1842 static void __fw_devlink_link_to_suppliers(struct device *dev,
1843 struct fwnode_handle *fwnode)
1845 bool own_link = (dev->fwnode == fwnode);
1846 struct fwnode_link *link, *tmp;
1847 struct fwnode_handle *child = NULL;
1851 dl_flags = fw_devlink_get_flags();
1853 dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
1855 list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
1857 struct device *sup_dev;
1858 struct fwnode_handle *sup = link->supplier;
1860 ret = fw_devlink_create_devlink(dev, sup, dl_flags);
1861 if (!own_link || ret == -EAGAIN)
1864 list_del(&link->s_hook);
1865 list_del(&link->c_hook);
1868 /* If no device link was created, nothing more to do. */
1873 * If a device link was successfully created to a supplier, we
1874 * now need to try and link the supplier to all its suppliers.
1876 * This is needed to detect and delete false dependencies in
1877 * fwnode links that haven't been converted to a device link
1878 * yet. See comments in fw_devlink_create_devlink() for more
1879 * details on the false dependency.
1881 * Without deleting these false dependencies, some devices will
1882 * never probe because they'll keep waiting for their false
1883 * dependency fwnode links to be converted to device links.
1885 sup_dev = get_dev_from_fwnode(sup);
1886 __fw_devlink_link_to_suppliers(sup_dev, sup_dev->fwnode);
1887 put_device(sup_dev);
1891 * Make "proxy" SYNC_STATE_ONLY device links to represent the needs of
1892 * all the descendants. This proxy link step is needed to handle the
1893 * case where the supplier is added before the consumer's parent device
1896 while ((child = fwnode_get_next_available_child_node(fwnode, child)))
1897 __fw_devlink_link_to_suppliers(dev, child);
1900 static void fw_devlink_link_device(struct device *dev)
1902 struct fwnode_handle *fwnode = dev->fwnode;
1904 if (!fw_devlink_flags)
1907 fw_devlink_parse_fwtree(fwnode);
1909 mutex_lock(&fwnode_link_lock);
1910 __fw_devlink_link_to_consumers(dev);
1911 __fw_devlink_link_to_suppliers(dev, fwnode);
1912 mutex_unlock(&fwnode_link_lock);
1915 /* Device links support end. */
1917 int (*platform_notify)(struct device *dev) = NULL;
1918 int (*platform_notify_remove)(struct device *dev) = NULL;
1919 static struct kobject *dev_kobj;
1920 struct kobject *sysfs_dev_char_kobj;
1921 struct kobject *sysfs_dev_block_kobj;
1923 static DEFINE_MUTEX(device_hotplug_lock);
1925 void lock_device_hotplug(void)
1927 mutex_lock(&device_hotplug_lock);
1930 void unlock_device_hotplug(void)
1932 mutex_unlock(&device_hotplug_lock);
1935 int lock_device_hotplug_sysfs(void)
1937 if (mutex_trylock(&device_hotplug_lock))
1940 /* Avoid busy looping (5 ms of sleep should do). */
1942 return restart_syscall();
1946 static inline int device_is_not_partition(struct device *dev)
1948 return !(dev->type == &part_type);
1951 static inline int device_is_not_partition(struct device *dev)
1958 device_platform_notify(struct device *dev, enum kobject_action action)
1962 ret = acpi_platform_notify(dev, action);
1966 ret = software_node_notify(dev, action);
1970 if (platform_notify && action == KOBJ_ADD)
1971 platform_notify(dev);
1972 else if (platform_notify_remove && action == KOBJ_REMOVE)
1973 platform_notify_remove(dev);
1978 * dev_driver_string - Return a device's driver name, if at all possible
1979 * @dev: struct device to get the name of
1981 * Will return the device's driver's name if it is bound to a device. If
1982 * the device is not bound to a driver, it will return the name of the bus
1983 * it is attached to. If it is not attached to a bus either, an empty
1984 * string will be returned.
1986 const char *dev_driver_string(const struct device *dev)
1988 struct device_driver *drv;
1990 /* dev->driver can change to NULL underneath us because of unbinding,
1991 * so be careful about accessing it. dev->bus and dev->class should
1992 * never change once they are set, so they don't need special care.
1994 drv = READ_ONCE(dev->driver);
1995 return drv ? drv->name : dev_bus_name(dev);
1997 EXPORT_SYMBOL(dev_driver_string);
1999 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
2001 static ssize_t dev_attr_show(struct kobject *kobj, struct attribute *attr,
2004 struct device_attribute *dev_attr = to_dev_attr(attr);
2005 struct device *dev = kobj_to_dev(kobj);
2009 ret = dev_attr->show(dev, dev_attr, buf);
2010 if (ret >= (ssize_t)PAGE_SIZE) {
2011 printk("dev_attr_show: %pS returned bad count\n",
2017 static ssize_t dev_attr_store(struct kobject *kobj, struct attribute *attr,
2018 const char *buf, size_t count)
2020 struct device_attribute *dev_attr = to_dev_attr(attr);
2021 struct device *dev = kobj_to_dev(kobj);
2024 if (dev_attr->store)
2025 ret = dev_attr->store(dev, dev_attr, buf, count);
2029 static const struct sysfs_ops dev_sysfs_ops = {
2030 .show = dev_attr_show,
2031 .store = dev_attr_store,
2034 #define to_ext_attr(x) container_of(x, struct dev_ext_attribute, attr)
2036 ssize_t device_store_ulong(struct device *dev,
2037 struct device_attribute *attr,
2038 const char *buf, size_t size)
2040 struct dev_ext_attribute *ea = to_ext_attr(attr);
2044 ret = kstrtoul(buf, 0, &new);
2047 *(unsigned long *)(ea->var) = new;
2048 /* Always return full write size even if we didn't consume all */
2051 EXPORT_SYMBOL_GPL(device_store_ulong);
2053 ssize_t device_show_ulong(struct device *dev,
2054 struct device_attribute *attr,
2057 struct dev_ext_attribute *ea = to_ext_attr(attr);
2058 return sysfs_emit(buf, "%lx\n", *(unsigned long *)(ea->var));
2060 EXPORT_SYMBOL_GPL(device_show_ulong);
2062 ssize_t device_store_int(struct device *dev,
2063 struct device_attribute *attr,
2064 const char *buf, size_t size)
2066 struct dev_ext_attribute *ea = to_ext_attr(attr);
2070 ret = kstrtol(buf, 0, &new);
2074 if (new > INT_MAX || new < INT_MIN)
2076 *(int *)(ea->var) = new;
2077 /* Always return full write size even if we didn't consume all */
2080 EXPORT_SYMBOL_GPL(device_store_int);
2082 ssize_t device_show_int(struct device *dev,
2083 struct device_attribute *attr,
2086 struct dev_ext_attribute *ea = to_ext_attr(attr);
2088 return sysfs_emit(buf, "%d\n", *(int *)(ea->var));
2090 EXPORT_SYMBOL_GPL(device_show_int);
2092 ssize_t device_store_bool(struct device *dev, struct device_attribute *attr,
2093 const char *buf, size_t size)
2095 struct dev_ext_attribute *ea = to_ext_attr(attr);
2097 if (strtobool(buf, ea->var) < 0)
2102 EXPORT_SYMBOL_GPL(device_store_bool);
2104 ssize_t device_show_bool(struct device *dev, struct device_attribute *attr,
2107 struct dev_ext_attribute *ea = to_ext_attr(attr);
2109 return sysfs_emit(buf, "%d\n", *(bool *)(ea->var));
2111 EXPORT_SYMBOL_GPL(device_show_bool);
2114 * device_release - free device structure.
2115 * @kobj: device's kobject.
2117 * This is called once the reference count for the object
2118 * reaches 0. We forward the call to the device's release
2119 * method, which should handle actually freeing the structure.
2121 static void device_release(struct kobject *kobj)
2123 struct device *dev = kobj_to_dev(kobj);
2124 struct device_private *p = dev->p;
2127 * Some platform devices are driven without driver attached
2128 * and managed resources may have been acquired. Make sure
2129 * all resources are released.
2131 * Drivers still can add resources into device after device
2132 * is deleted but alive, so release devres here to avoid
2133 * possible memory leak.
2135 devres_release_all(dev);
2137 kfree(dev->dma_range_map);
2141 else if (dev->type && dev->type->release)
2142 dev->type->release(dev);
2143 else if (dev->class && dev->class->dev_release)
2144 dev->class->dev_release(dev);
2146 WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
2151 static const void *device_namespace(struct kobject *kobj)
2153 struct device *dev = kobj_to_dev(kobj);
2154 const void *ns = NULL;
2156 if (dev->class && dev->class->ns_type)
2157 ns = dev->class->namespace(dev);
2162 static void device_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
2164 struct device *dev = kobj_to_dev(kobj);
2166 if (dev->class && dev->class->get_ownership)
2167 dev->class->get_ownership(dev, uid, gid);
2170 static struct kobj_type device_ktype = {
2171 .release = device_release,
2172 .sysfs_ops = &dev_sysfs_ops,
2173 .namespace = device_namespace,
2174 .get_ownership = device_get_ownership,
2178 static int dev_uevent_filter(struct kset *kset, struct kobject *kobj)
2180 struct kobj_type *ktype = get_ktype(kobj);
2182 if (ktype == &device_ktype) {
2183 struct device *dev = kobj_to_dev(kobj);
2192 static const char *dev_uevent_name(struct kset *kset, struct kobject *kobj)
2194 struct device *dev = kobj_to_dev(kobj);
2197 return dev->bus->name;
2199 return dev->class->name;
2203 static int dev_uevent(struct kset *kset, struct kobject *kobj,
2204 struct kobj_uevent_env *env)
2206 struct device *dev = kobj_to_dev(kobj);
2209 /* add device node properties if present */
2210 if (MAJOR(dev->devt)) {
2214 kuid_t uid = GLOBAL_ROOT_UID;
2215 kgid_t gid = GLOBAL_ROOT_GID;
2217 add_uevent_var(env, "MAJOR=%u", MAJOR(dev->devt));
2218 add_uevent_var(env, "MINOR=%u", MINOR(dev->devt));
2219 name = device_get_devnode(dev, &mode, &uid, &gid, &tmp);
2221 add_uevent_var(env, "DEVNAME=%s", name);
2223 add_uevent_var(env, "DEVMODE=%#o", mode & 0777);
2224 if (!uid_eq(uid, GLOBAL_ROOT_UID))
2225 add_uevent_var(env, "DEVUID=%u", from_kuid(&init_user_ns, uid));
2226 if (!gid_eq(gid, GLOBAL_ROOT_GID))
2227 add_uevent_var(env, "DEVGID=%u", from_kgid(&init_user_ns, gid));
2232 if (dev->type && dev->type->name)
2233 add_uevent_var(env, "DEVTYPE=%s", dev->type->name);
2236 add_uevent_var(env, "DRIVER=%s", dev->driver->name);
2238 /* Add common DT information about the device */
2239 of_device_uevent(dev, env);
2241 /* have the bus specific function add its stuff */
2242 if (dev->bus && dev->bus->uevent) {
2243 retval = dev->bus->uevent(dev, env);
2245 pr_debug("device: '%s': %s: bus uevent() returned %d\n",
2246 dev_name(dev), __func__, retval);
2249 /* have the class specific function add its stuff */
2250 if (dev->class && dev->class->dev_uevent) {
2251 retval = dev->class->dev_uevent(dev, env);
2253 pr_debug("device: '%s': %s: class uevent() "
2254 "returned %d\n", dev_name(dev),
2258 /* have the device type specific function add its stuff */
2259 if (dev->type && dev->type->uevent) {
2260 retval = dev->type->uevent(dev, env);
2262 pr_debug("device: '%s': %s: dev_type uevent() "
2263 "returned %d\n", dev_name(dev),
2270 static const struct kset_uevent_ops device_uevent_ops = {
2271 .filter = dev_uevent_filter,
2272 .name = dev_uevent_name,
2273 .uevent = dev_uevent,
2276 static ssize_t uevent_show(struct device *dev, struct device_attribute *attr,
2279 struct kobject *top_kobj;
2281 struct kobj_uevent_env *env = NULL;
2286 /* search the kset, the device belongs to */
2287 top_kobj = &dev->kobj;
2288 while (!top_kobj->kset && top_kobj->parent)
2289 top_kobj = top_kobj->parent;
2290 if (!top_kobj->kset)
2293 kset = top_kobj->kset;
2294 if (!kset->uevent_ops || !kset->uevent_ops->uevent)
2297 /* respect filter */
2298 if (kset->uevent_ops && kset->uevent_ops->filter)
2299 if (!kset->uevent_ops->filter(kset, &dev->kobj))
2302 env = kzalloc(sizeof(struct kobj_uevent_env), GFP_KERNEL);
2306 /* let the kset specific function add its keys */
2307 retval = kset->uevent_ops->uevent(kset, &dev->kobj, env);
2311 /* copy keys to file */
2312 for (i = 0; i < env->envp_idx; i++)
2313 len += sysfs_emit_at(buf, len, "%s\n", env->envp[i]);
2319 static ssize_t uevent_store(struct device *dev, struct device_attribute *attr,
2320 const char *buf, size_t count)
2324 rc = kobject_synth_uevent(&dev->kobj, buf, count);
2327 dev_err(dev, "uevent: failed to send synthetic uevent\n");
2333 static DEVICE_ATTR_RW(uevent);
2335 static ssize_t online_show(struct device *dev, struct device_attribute *attr,
2341 val = !dev->offline;
2343 return sysfs_emit(buf, "%u\n", val);
2346 static ssize_t online_store(struct device *dev, struct device_attribute *attr,
2347 const char *buf, size_t count)
2352 ret = strtobool(buf, &val);
2356 ret = lock_device_hotplug_sysfs();
2360 ret = val ? device_online(dev) : device_offline(dev);
2361 unlock_device_hotplug();
2362 return ret < 0 ? ret : count;
2364 static DEVICE_ATTR_RW(online);
2366 int device_add_groups(struct device *dev, const struct attribute_group **groups)
2368 return sysfs_create_groups(&dev->kobj, groups);
2370 EXPORT_SYMBOL_GPL(device_add_groups);
2372 void device_remove_groups(struct device *dev,
2373 const struct attribute_group **groups)
2375 sysfs_remove_groups(&dev->kobj, groups);
2377 EXPORT_SYMBOL_GPL(device_remove_groups);
2379 union device_attr_group_devres {
2380 const struct attribute_group *group;
2381 const struct attribute_group **groups;
2384 static int devm_attr_group_match(struct device *dev, void *res, void *data)
2386 return ((union device_attr_group_devres *)res)->group == data;
2389 static void devm_attr_group_remove(struct device *dev, void *res)
2391 union device_attr_group_devres *devres = res;
2392 const struct attribute_group *group = devres->group;
2394 dev_dbg(dev, "%s: removing group %p\n", __func__, group);
2395 sysfs_remove_group(&dev->kobj, group);
2398 static void devm_attr_groups_remove(struct device *dev, void *res)
2400 union device_attr_group_devres *devres = res;
2401 const struct attribute_group **groups = devres->groups;
2403 dev_dbg(dev, "%s: removing groups %p\n", __func__, groups);
2404 sysfs_remove_groups(&dev->kobj, groups);
2408 * devm_device_add_group - given a device, create a managed attribute group
2409 * @dev: The device to create the group for
2410 * @grp: The attribute group to create
2412 * This function creates a group for the first time. It will explicitly
2413 * warn and error if any of the attribute files being created already exist.
2415 * Returns 0 on success or error code on failure.
2417 int devm_device_add_group(struct device *dev, const struct attribute_group *grp)
2419 union device_attr_group_devres *devres;
2422 devres = devres_alloc(devm_attr_group_remove,
2423 sizeof(*devres), GFP_KERNEL);
2427 error = sysfs_create_group(&dev->kobj, grp);
2429 devres_free(devres);
2433 devres->group = grp;
2434 devres_add(dev, devres);
2437 EXPORT_SYMBOL_GPL(devm_device_add_group);
2440 * devm_device_remove_group: remove a managed group from a device
2441 * @dev: device to remove the group from
2442 * @grp: group to remove
2444 * This function removes a group of attributes from a device. The attributes
2445 * previously have to have been created for this group, otherwise it will fail.
2447 void devm_device_remove_group(struct device *dev,
2448 const struct attribute_group *grp)
2450 WARN_ON(devres_release(dev, devm_attr_group_remove,
2451 devm_attr_group_match,
2452 /* cast away const */ (void *)grp));
2454 EXPORT_SYMBOL_GPL(devm_device_remove_group);
2457 * devm_device_add_groups - create a bunch of managed attribute groups
2458 * @dev: The device to create the group for
2459 * @groups: The attribute groups to create, NULL terminated
2461 * This function creates a bunch of managed attribute groups. If an error
2462 * occurs when creating a group, all previously created groups will be
2463 * removed, unwinding everything back to the original state when this
2464 * function was called. It will explicitly warn and error if any of the
2465 * attribute files being created already exist.
2467 * Returns 0 on success or error code from sysfs_create_group on failure.
2469 int devm_device_add_groups(struct device *dev,
2470 const struct attribute_group **groups)
2472 union device_attr_group_devres *devres;
2475 devres = devres_alloc(devm_attr_groups_remove,
2476 sizeof(*devres), GFP_KERNEL);
2480 error = sysfs_create_groups(&dev->kobj, groups);
2482 devres_free(devres);
2486 devres->groups = groups;
2487 devres_add(dev, devres);
2490 EXPORT_SYMBOL_GPL(devm_device_add_groups);
2493 * devm_device_remove_groups - remove a list of managed groups
2495 * @dev: The device for the groups to be removed from
2496 * @groups: NULL terminated list of groups to be removed
2498 * If groups is not NULL, remove the specified groups from the device.
2500 void devm_device_remove_groups(struct device *dev,
2501 const struct attribute_group **groups)
2503 WARN_ON(devres_release(dev, devm_attr_groups_remove,
2504 devm_attr_group_match,
2505 /* cast away const */ (void *)groups));
2507 EXPORT_SYMBOL_GPL(devm_device_remove_groups);
2509 static int device_add_attrs(struct device *dev)
2511 struct class *class = dev->class;
2512 const struct device_type *type = dev->type;
2516 error = device_add_groups(dev, class->dev_groups);
2522 error = device_add_groups(dev, type->groups);
2524 goto err_remove_class_groups;
2527 error = device_add_groups(dev, dev->groups);
2529 goto err_remove_type_groups;
2531 if (device_supports_offline(dev) && !dev->offline_disabled) {
2532 error = device_create_file(dev, &dev_attr_online);
2534 goto err_remove_dev_groups;
2537 if (fw_devlink_flags && !fw_devlink_is_permissive() && dev->fwnode) {
2538 error = device_create_file(dev, &dev_attr_waiting_for_supplier);
2540 goto err_remove_dev_online;
2545 err_remove_dev_online:
2546 device_remove_file(dev, &dev_attr_online);
2547 err_remove_dev_groups:
2548 device_remove_groups(dev, dev->groups);
2549 err_remove_type_groups:
2551 device_remove_groups(dev, type->groups);
2552 err_remove_class_groups:
2554 device_remove_groups(dev, class->dev_groups);
2559 static void device_remove_attrs(struct device *dev)
2561 struct class *class = dev->class;
2562 const struct device_type *type = dev->type;
2564 device_remove_file(dev, &dev_attr_waiting_for_supplier);
2565 device_remove_file(dev, &dev_attr_online);
2566 device_remove_groups(dev, dev->groups);
2569 device_remove_groups(dev, type->groups);
2572 device_remove_groups(dev, class->dev_groups);
2575 static ssize_t dev_show(struct device *dev, struct device_attribute *attr,
2578 return print_dev_t(buf, dev->devt);
2580 static DEVICE_ATTR_RO(dev);
2583 struct kset *devices_kset;
2586 * devices_kset_move_before - Move device in the devices_kset's list.
2587 * @deva: Device to move.
2588 * @devb: Device @deva should come before.
2590 static void devices_kset_move_before(struct device *deva, struct device *devb)
2594 pr_debug("devices_kset: Moving %s before %s\n",
2595 dev_name(deva), dev_name(devb));
2596 spin_lock(&devices_kset->list_lock);
2597 list_move_tail(&deva->kobj.entry, &devb->kobj.entry);
2598 spin_unlock(&devices_kset->list_lock);
2602 * devices_kset_move_after - Move device in the devices_kset's list.
2603 * @deva: Device to move
2604 * @devb: Device @deva should come after.
2606 static void devices_kset_move_after(struct device *deva, struct device *devb)
2610 pr_debug("devices_kset: Moving %s after %s\n",
2611 dev_name(deva), dev_name(devb));
2612 spin_lock(&devices_kset->list_lock);
2613 list_move(&deva->kobj.entry, &devb->kobj.entry);
2614 spin_unlock(&devices_kset->list_lock);
2618 * devices_kset_move_last - move the device to the end of devices_kset's list.
2619 * @dev: device to move
2621 void devices_kset_move_last(struct device *dev)
2625 pr_debug("devices_kset: Moving %s to end of list\n", dev_name(dev));
2626 spin_lock(&devices_kset->list_lock);
2627 list_move_tail(&dev->kobj.entry, &devices_kset->list);
2628 spin_unlock(&devices_kset->list_lock);
2632 * device_create_file - create sysfs attribute file for device.
2634 * @attr: device attribute descriptor.
2636 int device_create_file(struct device *dev,
2637 const struct device_attribute *attr)
2642 WARN(((attr->attr.mode & S_IWUGO) && !attr->store),
2643 "Attribute %s: write permission without 'store'\n",
2645 WARN(((attr->attr.mode & S_IRUGO) && !attr->show),
2646 "Attribute %s: read permission without 'show'\n",
2648 error = sysfs_create_file(&dev->kobj, &attr->attr);
2653 EXPORT_SYMBOL_GPL(device_create_file);
2656 * device_remove_file - remove sysfs attribute file.
2658 * @attr: device attribute descriptor.
2660 void device_remove_file(struct device *dev,
2661 const struct device_attribute *attr)
2664 sysfs_remove_file(&dev->kobj, &attr->attr);
2666 EXPORT_SYMBOL_GPL(device_remove_file);
2669 * device_remove_file_self - remove sysfs attribute file from its own method.
2671 * @attr: device attribute descriptor.
2673 * See kernfs_remove_self() for details.
2675 bool device_remove_file_self(struct device *dev,
2676 const struct device_attribute *attr)
2679 return sysfs_remove_file_self(&dev->kobj, &attr->attr);
2683 EXPORT_SYMBOL_GPL(device_remove_file_self);
2686 * device_create_bin_file - create sysfs binary attribute file for device.
2688 * @attr: device binary attribute descriptor.
2690 int device_create_bin_file(struct device *dev,
2691 const struct bin_attribute *attr)
2693 int error = -EINVAL;
2695 error = sysfs_create_bin_file(&dev->kobj, attr);
2698 EXPORT_SYMBOL_GPL(device_create_bin_file);
2701 * device_remove_bin_file - remove sysfs binary attribute file
2703 * @attr: device binary attribute descriptor.
2705 void device_remove_bin_file(struct device *dev,
2706 const struct bin_attribute *attr)
2709 sysfs_remove_bin_file(&dev->kobj, attr);
2711 EXPORT_SYMBOL_GPL(device_remove_bin_file);
2713 static void klist_children_get(struct klist_node *n)
2715 struct device_private *p = to_device_private_parent(n);
2716 struct device *dev = p->device;
2721 static void klist_children_put(struct klist_node *n)
2723 struct device_private *p = to_device_private_parent(n);
2724 struct device *dev = p->device;
2730 * device_initialize - init device structure.
2733 * This prepares the device for use by other layers by initializing
2735 * It is the first half of device_register(), if called by
2736 * that function, though it can also be called separately, so one
2737 * may use @dev's fields. In particular, get_device()/put_device()
2738 * may be used for reference counting of @dev after calling this
2741 * All fields in @dev must be initialized by the caller to 0, except
2742 * for those explicitly set to some other value. The simplest
2743 * approach is to use kzalloc() to allocate the structure containing
2746 * NOTE: Use put_device() to give up your reference instead of freeing
2747 * @dev directly once you have called this function.
2749 void device_initialize(struct device *dev)
2751 dev->kobj.kset = devices_kset;
2752 kobject_init(&dev->kobj, &device_ktype);
2753 INIT_LIST_HEAD(&dev->dma_pools);
2754 mutex_init(&dev->mutex);
2755 #ifdef CONFIG_PROVE_LOCKING
2756 mutex_init(&dev->lockdep_mutex);
2758 lockdep_set_novalidate_class(&dev->mutex);
2759 spin_lock_init(&dev->devres_lock);
2760 INIT_LIST_HEAD(&dev->devres_head);
2761 device_pm_init(dev);
2762 set_dev_node(dev, -1);
2763 #ifdef CONFIG_GENERIC_MSI_IRQ
2764 INIT_LIST_HEAD(&dev->msi_list);
2766 INIT_LIST_HEAD(&dev->links.consumers);
2767 INIT_LIST_HEAD(&dev->links.suppliers);
2768 INIT_LIST_HEAD(&dev->links.defer_sync);
2769 dev->links.status = DL_DEV_NO_DRIVER;
2770 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
2771 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
2772 defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
2773 dev->dma_coherent = dma_default_coherent;
2776 EXPORT_SYMBOL_GPL(device_initialize);
2778 struct kobject *virtual_device_parent(struct device *dev)
2780 static struct kobject *virtual_dir = NULL;
2783 virtual_dir = kobject_create_and_add("virtual",
2784 &devices_kset->kobj);
2790 struct kobject kobj;
2791 struct class *class;
2794 #define to_class_dir(obj) container_of(obj, struct class_dir, kobj)
2796 static void class_dir_release(struct kobject *kobj)
2798 struct class_dir *dir = to_class_dir(kobj);
2803 struct kobj_ns_type_operations *class_dir_child_ns_type(struct kobject *kobj)
2805 struct class_dir *dir = to_class_dir(kobj);
2806 return dir->class->ns_type;
2809 static struct kobj_type class_dir_ktype = {
2810 .release = class_dir_release,
2811 .sysfs_ops = &kobj_sysfs_ops,
2812 .child_ns_type = class_dir_child_ns_type
2815 static struct kobject *
2816 class_dir_create_and_add(struct class *class, struct kobject *parent_kobj)
2818 struct class_dir *dir;
2821 dir = kzalloc(sizeof(*dir), GFP_KERNEL);
2823 return ERR_PTR(-ENOMEM);
2826 kobject_init(&dir->kobj, &class_dir_ktype);
2828 dir->kobj.kset = &class->p->glue_dirs;
2830 retval = kobject_add(&dir->kobj, parent_kobj, "%s", class->name);
2832 kobject_put(&dir->kobj);
2833 return ERR_PTR(retval);
2838 static DEFINE_MUTEX(gdp_mutex);
2840 static struct kobject *get_device_parent(struct device *dev,
2841 struct device *parent)
2844 struct kobject *kobj = NULL;
2845 struct kobject *parent_kobj;
2849 /* block disks show up in /sys/block */
2850 if (sysfs_deprecated && dev->class == &block_class) {
2851 if (parent && parent->class == &block_class)
2852 return &parent->kobj;
2853 return &block_class.p->subsys.kobj;
2858 * If we have no parent, we live in "virtual".
2859 * Class-devices with a non class-device as parent, live
2860 * in a "glue" directory to prevent namespace collisions.
2863 parent_kobj = virtual_device_parent(dev);
2864 else if (parent->class && !dev->class->ns_type)
2865 return &parent->kobj;
2867 parent_kobj = &parent->kobj;
2869 mutex_lock(&gdp_mutex);
2871 /* find our class-directory at the parent and reference it */
2872 spin_lock(&dev->class->p->glue_dirs.list_lock);
2873 list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
2874 if (k->parent == parent_kobj) {
2875 kobj = kobject_get(k);
2878 spin_unlock(&dev->class->p->glue_dirs.list_lock);
2880 mutex_unlock(&gdp_mutex);
2884 /* or create a new class-directory at the parent device */
2885 k = class_dir_create_and_add(dev->class, parent_kobj);
2886 /* do not emit an uevent for this simple "glue" directory */
2887 mutex_unlock(&gdp_mutex);
2891 /* subsystems can specify a default root directory for their devices */
2892 if (!parent && dev->bus && dev->bus->dev_root)
2893 return &dev->bus->dev_root->kobj;
2896 return &parent->kobj;
2900 static inline bool live_in_glue_dir(struct kobject *kobj,
2903 if (!kobj || !dev->class ||
2904 kobj->kset != &dev->class->p->glue_dirs)
2909 static inline struct kobject *get_glue_dir(struct device *dev)
2911 return dev->kobj.parent;
2915 * make sure cleaning up dir as the last step, we need to make
2916 * sure .release handler of kobject is run with holding the
2919 static void cleanup_glue_dir(struct device *dev, struct kobject *glue_dir)
2923 /* see if we live in a "glue" directory */
2924 if (!live_in_glue_dir(glue_dir, dev))
2927 mutex_lock(&gdp_mutex);
2929 * There is a race condition between removing glue directory
2930 * and adding a new device under the glue directory.
2935 * get_device_parent()
2936 * class_dir_create_and_add()
2937 * kobject_add_internal()
2938 * create_dir() // create glue_dir
2941 * get_device_parent()
2942 * kobject_get() // get glue_dir
2945 * cleanup_glue_dir()
2946 * kobject_del(glue_dir)
2949 * kobject_add_internal()
2950 * create_dir() // in glue_dir
2951 * sysfs_create_dir_ns()
2952 * kernfs_create_dir_ns(sd)
2954 * sysfs_remove_dir() // glue_dir->sd=NULL
2955 * sysfs_put() // free glue_dir->sd
2958 * kernfs_new_node(sd)
2959 * kernfs_get(glue_dir)
2963 * Before CPU1 remove last child device under glue dir, if CPU2 add
2964 * a new device under glue dir, the glue_dir kobject reference count
2965 * will be increase to 2 in kobject_get(k). And CPU2 has been called
2966 * kernfs_create_dir_ns(). Meanwhile, CPU1 call sysfs_remove_dir()
2967 * and sysfs_put(). This result in glue_dir->sd is freed.
2969 * Then the CPU2 will see a stale "empty" but still potentially used
2970 * glue dir around in kernfs_new_node().
2972 * In order to avoid this happening, we also should make sure that
2973 * kernfs_node for glue_dir is released in CPU1 only when refcount
2974 * for glue_dir kobj is 1.
2976 ref = kref_read(&glue_dir->kref);
2977 if (!kobject_has_children(glue_dir) && !--ref)
2978 kobject_del(glue_dir);
2979 kobject_put(glue_dir);
2980 mutex_unlock(&gdp_mutex);
2983 static int device_add_class_symlinks(struct device *dev)
2985 struct device_node *of_node = dev_of_node(dev);
2989 error = sysfs_create_link(&dev->kobj, of_node_kobj(of_node), "of_node");
2991 dev_warn(dev, "Error %d creating of_node link\n",error);
2992 /* An error here doesn't warrant bringing down the device */
2998 error = sysfs_create_link(&dev->kobj,
2999 &dev->class->p->subsys.kobj,
3004 if (dev->parent && device_is_not_partition(dev)) {
3005 error = sysfs_create_link(&dev->kobj, &dev->parent->kobj,
3012 /* /sys/block has directories and does not need symlinks */
3013 if (sysfs_deprecated && dev->class == &block_class)
3017 /* link in the class directory pointing to the device */
3018 error = sysfs_create_link(&dev->class->p->subsys.kobj,
3019 &dev->kobj, dev_name(dev));
3026 sysfs_remove_link(&dev->kobj, "device");
3029 sysfs_remove_link(&dev->kobj, "subsystem");
3031 sysfs_remove_link(&dev->kobj, "of_node");
3035 static void device_remove_class_symlinks(struct device *dev)
3037 if (dev_of_node(dev))
3038 sysfs_remove_link(&dev->kobj, "of_node");
3043 if (dev->parent && device_is_not_partition(dev))
3044 sysfs_remove_link(&dev->kobj, "device");
3045 sysfs_remove_link(&dev->kobj, "subsystem");
3047 if (sysfs_deprecated && dev->class == &block_class)
3050 sysfs_delete_link(&dev->class->p->subsys.kobj, &dev->kobj, dev_name(dev));
3054 * dev_set_name - set a device name
3056 * @fmt: format string for the device's name
3058 int dev_set_name(struct device *dev, const char *fmt, ...)
3063 va_start(vargs, fmt);
3064 err = kobject_set_name_vargs(&dev->kobj, fmt, vargs);
3068 EXPORT_SYMBOL_GPL(dev_set_name);
3071 * device_to_dev_kobj - select a /sys/dev/ directory for the device
3074 * By default we select char/ for new entries. Setting class->dev_obj
3075 * to NULL prevents an entry from being created. class->dev_kobj must
3076 * be set (or cleared) before any devices are registered to the class
3077 * otherwise device_create_sys_dev_entry() and
3078 * device_remove_sys_dev_entry() will disagree about the presence of
3081 static struct kobject *device_to_dev_kobj(struct device *dev)
3083 struct kobject *kobj;
3086 kobj = dev->class->dev_kobj;
3088 kobj = sysfs_dev_char_kobj;
3093 static int device_create_sys_dev_entry(struct device *dev)
3095 struct kobject *kobj = device_to_dev_kobj(dev);
3100 format_dev_t(devt_str, dev->devt);
3101 error = sysfs_create_link(kobj, &dev->kobj, devt_str);
3107 static void device_remove_sys_dev_entry(struct device *dev)
3109 struct kobject *kobj = device_to_dev_kobj(dev);
3113 format_dev_t(devt_str, dev->devt);
3114 sysfs_remove_link(kobj, devt_str);
3118 static int device_private_init(struct device *dev)
3120 dev->p = kzalloc(sizeof(*dev->p), GFP_KERNEL);
3123 dev->p->device = dev;
3124 klist_init(&dev->p->klist_children, klist_children_get,
3125 klist_children_put);
3126 INIT_LIST_HEAD(&dev->p->deferred_probe);
3131 * device_add - add device to device hierarchy.
3134 * This is part 2 of device_register(), though may be called
3135 * separately _iff_ device_initialize() has been called separately.
3137 * This adds @dev to the kobject hierarchy via kobject_add(), adds it
3138 * to the global and sibling lists for the device, then
3139 * adds it to the other relevant subsystems of the driver model.
3141 * Do not call this routine or device_register() more than once for
3142 * any device structure. The driver model core is not designed to work
3143 * with devices that get unregistered and then spring back to life.
3144 * (Among other things, it's very hard to guarantee that all references
3145 * to the previous incarnation of @dev have been dropped.) Allocate
3146 * and register a fresh new struct device instead.
3148 * NOTE: _Never_ directly free @dev after calling this function, even
3149 * if it returned an error! Always use put_device() to give up your
3150 * reference instead.
3152 * Rule of thumb is: if device_add() succeeds, you should call
3153 * device_del() when you want to get rid of it. If device_add() has
3154 * *not* succeeded, use *only* put_device() to drop the reference
3157 int device_add(struct device *dev)
3159 struct device *parent;
3160 struct kobject *kobj;
3161 struct class_interface *class_intf;
3162 int error = -EINVAL;
3163 struct kobject *glue_dir = NULL;
3165 dev = get_device(dev);
3170 error = device_private_init(dev);
3176 * for statically allocated devices, which should all be converted
3177 * some day, we need to initialize the name. We prevent reading back
3178 * the name, and force the use of dev_name()
3180 if (dev->init_name) {
3181 dev_set_name(dev, "%s", dev->init_name);
3182 dev->init_name = NULL;
3185 /* subsystems can specify simple device enumeration */
3186 if (!dev_name(dev) && dev->bus && dev->bus->dev_name)
3187 dev_set_name(dev, "%s%u", dev->bus->dev_name, dev->id);
3189 if (!dev_name(dev)) {
3194 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
3196 parent = get_device(dev->parent);
3197 kobj = get_device_parent(dev, parent);
3199 error = PTR_ERR(kobj);
3203 dev->kobj.parent = kobj;
3205 /* use parent numa_node */
3206 if (parent && (dev_to_node(dev) == NUMA_NO_NODE))
3207 set_dev_node(dev, dev_to_node(parent));
3209 /* first, register with generic layer. */
3210 /* we require the name to be set before, and pass NULL */
3211 error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
3213 glue_dir = get_glue_dir(dev);
3217 /* notify platform of device entry */
3218 error = device_platform_notify(dev, KOBJ_ADD);
3220 goto platform_error;
3222 error = device_create_file(dev, &dev_attr_uevent);
3226 error = device_add_class_symlinks(dev);
3229 error = device_add_attrs(dev);
3232 error = bus_add_device(dev);
3235 error = dpm_sysfs_add(dev);
3240 if (MAJOR(dev->devt)) {
3241 error = device_create_file(dev, &dev_attr_dev);
3245 error = device_create_sys_dev_entry(dev);
3249 devtmpfs_create_node(dev);
3252 /* Notify clients of device addition. This call must come
3253 * after dpm_sysfs_add() and before kobject_uevent().
3256 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
3257 BUS_NOTIFY_ADD_DEVICE, dev);
3259 kobject_uevent(&dev->kobj, KOBJ_ADD);
3262 * Check if any of the other devices (consumers) have been waiting for
3263 * this device (supplier) to be added so that they can create a device
3266 * This needs to happen after device_pm_add() because device_link_add()
3267 * requires the supplier be registered before it's called.
3269 * But this also needs to happen before bus_probe_device() to make sure
3270 * waiting consumers can link to it before the driver is bound to the
3271 * device and the driver sync_state callback is called for this device.
3273 if (dev->fwnode && !dev->fwnode->dev) {
3274 dev->fwnode->dev = dev;
3275 fw_devlink_link_device(dev);
3278 bus_probe_device(dev);
3280 klist_add_tail(&dev->p->knode_parent,
3281 &parent->p->klist_children);
3284 mutex_lock(&dev->class->p->mutex);
3285 /* tie the class to the device */
3286 klist_add_tail(&dev->p->knode_class,
3287 &dev->class->p->klist_devices);
3289 /* notify any interfaces that the device is here */
3290 list_for_each_entry(class_intf,
3291 &dev->class->p->interfaces, node)
3292 if (class_intf->add_dev)
3293 class_intf->add_dev(dev, class_intf);
3294 mutex_unlock(&dev->class->p->mutex);
3300 if (MAJOR(dev->devt))
3301 device_remove_file(dev, &dev_attr_dev);
3303 device_pm_remove(dev);
3304 dpm_sysfs_remove(dev);
3306 bus_remove_device(dev);
3308 device_remove_attrs(dev);
3310 device_remove_class_symlinks(dev);
3312 device_remove_file(dev, &dev_attr_uevent);
3314 device_platform_notify(dev, KOBJ_REMOVE);
3316 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
3317 glue_dir = get_glue_dir(dev);
3318 kobject_del(&dev->kobj);
3320 cleanup_glue_dir(dev, glue_dir);
3328 EXPORT_SYMBOL_GPL(device_add);
3331 * device_register - register a device with the system.
3332 * @dev: pointer to the device structure
3334 * This happens in two clean steps - initialize the device
3335 * and add it to the system. The two steps can be called
3336 * separately, but this is the easiest and most common.
3337 * I.e. you should only call the two helpers separately if
3338 * have a clearly defined need to use and refcount the device
3339 * before it is added to the hierarchy.
3341 * For more information, see the kerneldoc for device_initialize()
3344 * NOTE: _Never_ directly free @dev after calling this function, even
3345 * if it returned an error! Always use put_device() to give up the
3346 * reference initialized in this function instead.
3348 int device_register(struct device *dev)
3350 device_initialize(dev);
3351 return device_add(dev);
3353 EXPORT_SYMBOL_GPL(device_register);
3356 * get_device - increment reference count for device.
3359 * This simply forwards the call to kobject_get(), though
3360 * we do take care to provide for the case that we get a NULL
3361 * pointer passed in.
3363 struct device *get_device(struct device *dev)
3365 return dev ? kobj_to_dev(kobject_get(&dev->kobj)) : NULL;
3367 EXPORT_SYMBOL_GPL(get_device);
3370 * put_device - decrement reference count.
3371 * @dev: device in question.
3373 void put_device(struct device *dev)
3375 /* might_sleep(); */
3377 kobject_put(&dev->kobj);
3379 EXPORT_SYMBOL_GPL(put_device);
3381 bool kill_device(struct device *dev)
3384 * Require the device lock and set the "dead" flag to guarantee that
3385 * the update behavior is consistent with the other bitfields near
3386 * it and that we cannot have an asynchronous probe routine trying
3387 * to run while we are tearing out the bus/class/sysfs from
3388 * underneath the device.
3390 lockdep_assert_held(&dev->mutex);
3394 dev->p->dead = true;
3397 EXPORT_SYMBOL_GPL(kill_device);
3400 * device_del - delete device from system.
3403 * This is the first part of the device unregistration
3404 * sequence. This removes the device from the lists we control
3405 * from here, has it removed from the other driver model
3406 * subsystems it was added to in device_add(), and removes it
3407 * from the kobject hierarchy.
3409 * NOTE: this should be called manually _iff_ device_add() was
3410 * also called manually.
3412 void device_del(struct device *dev)
3414 struct device *parent = dev->parent;
3415 struct kobject *glue_dir = NULL;
3416 struct class_interface *class_intf;
3417 unsigned int noio_flag;
3423 if (dev->fwnode && dev->fwnode->dev == dev)
3424 dev->fwnode->dev = NULL;
3426 /* Notify clients of device removal. This call must come
3427 * before dpm_sysfs_remove().
3429 noio_flag = memalloc_noio_save();
3431 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
3432 BUS_NOTIFY_DEL_DEVICE, dev);
3434 dpm_sysfs_remove(dev);
3436 klist_del(&dev->p->knode_parent);
3437 if (MAJOR(dev->devt)) {
3438 devtmpfs_delete_node(dev);
3439 device_remove_sys_dev_entry(dev);
3440 device_remove_file(dev, &dev_attr_dev);
3443 device_remove_class_symlinks(dev);
3445 mutex_lock(&dev->class->p->mutex);
3446 /* notify any interfaces that the device is now gone */
3447 list_for_each_entry(class_intf,
3448 &dev->class->p->interfaces, node)
3449 if (class_intf->remove_dev)
3450 class_intf->remove_dev(dev, class_intf);
3451 /* remove the device from the class list */
3452 klist_del(&dev->p->knode_class);
3453 mutex_unlock(&dev->class->p->mutex);
3455 device_remove_file(dev, &dev_attr_uevent);
3456 device_remove_attrs(dev);
3457 bus_remove_device(dev);
3458 device_pm_remove(dev);
3459 driver_deferred_probe_del(dev);
3460 device_platform_notify(dev, KOBJ_REMOVE);
3461 device_remove_properties(dev);
3462 device_links_purge(dev);
3465 blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
3466 BUS_NOTIFY_REMOVED_DEVICE, dev);
3467 kobject_uevent(&dev->kobj, KOBJ_REMOVE);
3468 glue_dir = get_glue_dir(dev);
3469 kobject_del(&dev->kobj);
3470 cleanup_glue_dir(dev, glue_dir);
3471 memalloc_noio_restore(noio_flag);
3474 EXPORT_SYMBOL_GPL(device_del);
3477 * device_unregister - unregister device from system.
3478 * @dev: device going away.
3480 * We do this in two parts, like we do device_register(). First,
3481 * we remove it from all the subsystems with device_del(), then
3482 * we decrement the reference count via put_device(). If that
3483 * is the final reference count, the device will be cleaned up
3484 * via device_release() above. Otherwise, the structure will
3485 * stick around until the final reference to the device is dropped.
3487 void device_unregister(struct device *dev)
3489 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
3493 EXPORT_SYMBOL_GPL(device_unregister);
3495 static struct device *prev_device(struct klist_iter *i)
3497 struct klist_node *n = klist_prev(i);
3498 struct device *dev = NULL;
3499 struct device_private *p;
3502 p = to_device_private_parent(n);
3508 static struct device *next_device(struct klist_iter *i)
3510 struct klist_node *n = klist_next(i);
3511 struct device *dev = NULL;
3512 struct device_private *p;
3515 p = to_device_private_parent(n);
3522 * device_get_devnode - path of device node file
3524 * @mode: returned file access mode
3525 * @uid: returned file owner
3526 * @gid: returned file group
3527 * @tmp: possibly allocated string
3529 * Return the relative path of a possible device node.
3530 * Non-default names may need to allocate a memory to compose
3531 * a name. This memory is returned in tmp and needs to be
3532 * freed by the caller.
3534 const char *device_get_devnode(struct device *dev,
3535 umode_t *mode, kuid_t *uid, kgid_t *gid,
3542 /* the device type may provide a specific name */
3543 if (dev->type && dev->type->devnode)
3544 *tmp = dev->type->devnode(dev, mode, uid, gid);
3548 /* the class may provide a specific name */
3549 if (dev->class && dev->class->devnode)
3550 *tmp = dev->class->devnode(dev, mode);
3554 /* return name without allocation, tmp == NULL */
3555 if (strchr(dev_name(dev), '!') == NULL)
3556 return dev_name(dev);
3558 /* replace '!' in the name with '/' */
3559 s = kstrdup(dev_name(dev), GFP_KERNEL);
3562 strreplace(s, '!', '/');
3567 * device_for_each_child - device child iterator.
3568 * @parent: parent struct device.
3569 * @fn: function to be called for each device.
3570 * @data: data for the callback.
3572 * Iterate over @parent's child devices, and call @fn for each,
3575 * We check the return of @fn each time. If it returns anything
3576 * other than 0, we break out and return that value.
3578 int device_for_each_child(struct device *parent, void *data,
3579 int (*fn)(struct device *dev, void *data))
3581 struct klist_iter i;
3582 struct device *child;
3588 klist_iter_init(&parent->p->klist_children, &i);
3589 while (!error && (child = next_device(&i)))
3590 error = fn(child, data);
3591 klist_iter_exit(&i);
3594 EXPORT_SYMBOL_GPL(device_for_each_child);
3597 * device_for_each_child_reverse - device child iterator in reversed order.
3598 * @parent: parent struct device.
3599 * @fn: function to be called for each device.
3600 * @data: data for the callback.
3602 * Iterate over @parent's child devices, and call @fn for each,
3605 * We check the return of @fn each time. If it returns anything
3606 * other than 0, we break out and return that value.
3608 int device_for_each_child_reverse(struct device *parent, void *data,
3609 int (*fn)(struct device *dev, void *data))
3611 struct klist_iter i;
3612 struct device *child;
3618 klist_iter_init(&parent->p->klist_children, &i);
3619 while ((child = prev_device(&i)) && !error)
3620 error = fn(child, data);
3621 klist_iter_exit(&i);
3624 EXPORT_SYMBOL_GPL(device_for_each_child_reverse);
3627 * device_find_child - device iterator for locating a particular device.
3628 * @parent: parent struct device
3629 * @match: Callback function to check device
3630 * @data: Data to pass to match function
3632 * This is similar to the device_for_each_child() function above, but it
3633 * returns a reference to a device that is 'found' for later use, as
3634 * determined by the @match callback.
3636 * The callback should return 0 if the device doesn't match and non-zero
3637 * if it does. If the callback returns non-zero and a reference to the
3638 * current device can be obtained, this function will return to the caller
3639 * and not iterate over any more devices.
3641 * NOTE: you will need to drop the reference with put_device() after use.
3643 struct device *device_find_child(struct device *parent, void *data,
3644 int (*match)(struct device *dev, void *data))
3646 struct klist_iter i;
3647 struct device *child;
3652 klist_iter_init(&parent->p->klist_children, &i);
3653 while ((child = next_device(&i)))
3654 if (match(child, data) && get_device(child))
3656 klist_iter_exit(&i);
3659 EXPORT_SYMBOL_GPL(device_find_child);
3662 * device_find_child_by_name - device iterator for locating a child device.
3663 * @parent: parent struct device
3664 * @name: name of the child device
3666 * This is similar to the device_find_child() function above, but it
3667 * returns a reference to a device that has the name @name.
3669 * NOTE: you will need to drop the reference with put_device() after use.
3671 struct device *device_find_child_by_name(struct device *parent,
3674 struct klist_iter i;
3675 struct device *child;
3680 klist_iter_init(&parent->p->klist_children, &i);
3681 while ((child = next_device(&i)))
3682 if (sysfs_streq(dev_name(child), name) && get_device(child))
3684 klist_iter_exit(&i);
3687 EXPORT_SYMBOL_GPL(device_find_child_by_name);
3689 int __init devices_init(void)
3691 devices_kset = kset_create_and_add("devices", &device_uevent_ops, NULL);
3694 dev_kobj = kobject_create_and_add("dev", NULL);
3697 sysfs_dev_block_kobj = kobject_create_and_add("block", dev_kobj);
3698 if (!sysfs_dev_block_kobj)
3699 goto block_kobj_err;
3700 sysfs_dev_char_kobj = kobject_create_and_add("char", dev_kobj);
3701 if (!sysfs_dev_char_kobj)
3707 kobject_put(sysfs_dev_block_kobj);
3709 kobject_put(dev_kobj);
3711 kset_unregister(devices_kset);
3715 static int device_check_offline(struct device *dev, void *not_used)
3719 ret = device_for_each_child(dev, NULL, device_check_offline);
3723 return device_supports_offline(dev) && !dev->offline ? -EBUSY : 0;
3727 * device_offline - Prepare the device for hot-removal.
3728 * @dev: Device to be put offline.
3730 * Execute the device bus type's .offline() callback, if present, to prepare
3731 * the device for a subsequent hot-removal. If that succeeds, the device must
3732 * not be used until either it is removed or its bus type's .online() callback
3735 * Call under device_hotplug_lock.
3737 int device_offline(struct device *dev)
3741 if (dev->offline_disabled)
3744 ret = device_for_each_child(dev, NULL, device_check_offline);
3749 if (device_supports_offline(dev)) {
3753 ret = dev->bus->offline(dev);
3755 kobject_uevent(&dev->kobj, KOBJ_OFFLINE);
3756 dev->offline = true;
3766 * device_online - Put the device back online after successful device_offline().
3767 * @dev: Device to be put back online.
3769 * If device_offline() has been successfully executed for @dev, but the device
3770 * has not been removed subsequently, execute its bus type's .online() callback
3771 * to indicate that the device can be used again.
3773 * Call under device_hotplug_lock.
3775 int device_online(struct device *dev)
3780 if (device_supports_offline(dev)) {
3782 ret = dev->bus->online(dev);
3784 kobject_uevent(&dev->kobj, KOBJ_ONLINE);
3785 dev->offline = false;
3796 struct root_device {
3798 struct module *owner;
3801 static inline struct root_device *to_root_device(struct device *d)
3803 return container_of(d, struct root_device, dev);
3806 static void root_device_release(struct device *dev)
3808 kfree(to_root_device(dev));
3812 * __root_device_register - allocate and register a root device
3813 * @name: root device name
3814 * @owner: owner module of the root device, usually THIS_MODULE
3816 * This function allocates a root device and registers it
3817 * using device_register(). In order to free the returned
3818 * device, use root_device_unregister().
3820 * Root devices are dummy devices which allow other devices
3821 * to be grouped under /sys/devices. Use this function to
3822 * allocate a root device and then use it as the parent of
3823 * any device which should appear under /sys/devices/{name}
3825 * The /sys/devices/{name} directory will also contain a
3826 * 'module' symlink which points to the @owner directory
3829 * Returns &struct device pointer on success, or ERR_PTR() on error.
3831 * Note: You probably want to use root_device_register().
3833 struct device *__root_device_register(const char *name, struct module *owner)
3835 struct root_device *root;
3838 root = kzalloc(sizeof(struct root_device), GFP_KERNEL);
3840 return ERR_PTR(err);
3842 err = dev_set_name(&root->dev, "%s", name);
3845 return ERR_PTR(err);
3848 root->dev.release = root_device_release;
3850 err = device_register(&root->dev);
3852 put_device(&root->dev);
3853 return ERR_PTR(err);
3856 #ifdef CONFIG_MODULES /* gotta find a "cleaner" way to do this */
3858 struct module_kobject *mk = &owner->mkobj;
3860 err = sysfs_create_link(&root->dev.kobj, &mk->kobj, "module");
3862 device_unregister(&root->dev);
3863 return ERR_PTR(err);
3865 root->owner = owner;
3871 EXPORT_SYMBOL_GPL(__root_device_register);
3874 * root_device_unregister - unregister and free a root device
3875 * @dev: device going away
3877 * This function unregisters and cleans up a device that was created by
3878 * root_device_register().
3880 void root_device_unregister(struct device *dev)
3882 struct root_device *root = to_root_device(dev);
3885 sysfs_remove_link(&root->dev.kobj, "module");
3887 device_unregister(dev);
3889 EXPORT_SYMBOL_GPL(root_device_unregister);
3892 static void device_create_release(struct device *dev)
3894 pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
3898 static __printf(6, 0) struct device *
3899 device_create_groups_vargs(struct class *class, struct device *parent,
3900 dev_t devt, void *drvdata,
3901 const struct attribute_group **groups,
3902 const char *fmt, va_list args)
3904 struct device *dev = NULL;
3905 int retval = -ENODEV;
3907 if (class == NULL || IS_ERR(class))
3910 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
3916 device_initialize(dev);
3919 dev->parent = parent;
3920 dev->groups = groups;
3921 dev->release = device_create_release;
3922 dev_set_drvdata(dev, drvdata);
3924 retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
3928 retval = device_add(dev);
3936 return ERR_PTR(retval);
3940 * device_create - creates a device and registers it with sysfs
3941 * @class: pointer to the struct class that this device should be registered to
3942 * @parent: pointer to the parent struct device of this new device, if any
3943 * @devt: the dev_t for the char device to be added
3944 * @drvdata: the data to be added to the device for callbacks
3945 * @fmt: string for the device's name
3947 * This function can be used by char device classes. A struct device
3948 * will be created in sysfs, registered to the specified class.
3950 * A "dev" file will be created, showing the dev_t for the device, if
3951 * the dev_t is not 0,0.
3952 * If a pointer to a parent struct device is passed in, the newly created
3953 * struct device will be a child of that device in sysfs.
3954 * The pointer to the struct device will be returned from the call.
3955 * Any further sysfs files that might be required can be created using this
3958 * Returns &struct device pointer on success, or ERR_PTR() on error.
3960 * Note: the struct class passed to this function must have previously
3961 * been created with a call to class_create().
3963 struct device *device_create(struct class *class, struct device *parent,
3964 dev_t devt, void *drvdata, const char *fmt, ...)
3969 va_start(vargs, fmt);
3970 dev = device_create_groups_vargs(class, parent, devt, drvdata, NULL,
3975 EXPORT_SYMBOL_GPL(device_create);
3978 * device_create_with_groups - creates a device and registers it with sysfs
3979 * @class: pointer to the struct class that this device should be registered to
3980 * @parent: pointer to the parent struct device of this new device, if any
3981 * @devt: the dev_t for the char device to be added
3982 * @drvdata: the data to be added to the device for callbacks
3983 * @groups: NULL-terminated list of attribute groups to be created
3984 * @fmt: string for the device's name
3986 * This function can be used by char device classes. A struct device
3987 * will be created in sysfs, registered to the specified class.
3988 * Additional attributes specified in the groups parameter will also
3989 * be created automatically.
3991 * A "dev" file will be created, showing the dev_t for the device, if
3992 * the dev_t is not 0,0.
3993 * If a pointer to a parent struct device is passed in, the newly created
3994 * struct device will be a child of that device in sysfs.
3995 * The pointer to the struct device will be returned from the call.
3996 * Any further sysfs files that might be required can be created using this
3999 * Returns &struct device pointer on success, or ERR_PTR() on error.
4001 * Note: the struct class passed to this function must have previously
4002 * been created with a call to class_create().
4004 struct device *device_create_with_groups(struct class *class,
4005 struct device *parent, dev_t devt,
4007 const struct attribute_group **groups,
4008 const char *fmt, ...)
4013 va_start(vargs, fmt);
4014 dev = device_create_groups_vargs(class, parent, devt, drvdata, groups,
4019 EXPORT_SYMBOL_GPL(device_create_with_groups);
4022 * device_destroy - removes a device that was created with device_create()
4023 * @class: pointer to the struct class that this device was registered with
4024 * @devt: the dev_t of the device that was previously registered
4026 * This call unregisters and cleans up a device that was created with a
4027 * call to device_create().
4029 void device_destroy(struct class *class, dev_t devt)
4033 dev = class_find_device_by_devt(class, devt);
4036 device_unregister(dev);
4039 EXPORT_SYMBOL_GPL(device_destroy);
4042 * device_rename - renames a device
4043 * @dev: the pointer to the struct device to be renamed
4044 * @new_name: the new name of the device
4046 * It is the responsibility of the caller to provide mutual
4047 * exclusion between two different calls of device_rename
4048 * on the same device to ensure that new_name is valid and
4049 * won't conflict with other devices.
4051 * Note: Don't call this function. Currently, the networking layer calls this
4052 * function, but that will change. The following text from Kay Sievers offers
4055 * Renaming devices is racy at many levels, symlinks and other stuff are not
4056 * replaced atomically, and you get a "move" uevent, but it's not easy to
4057 * connect the event to the old and new device. Device nodes are not renamed at
4058 * all, there isn't even support for that in the kernel now.
4060 * In the meantime, during renaming, your target name might be taken by another
4061 * driver, creating conflicts. Or the old name is taken directly after you
4062 * renamed it -- then you get events for the same DEVPATH, before you even see
4063 * the "move" event. It's just a mess, and nothing new should ever rely on
4064 * kernel device renaming. Besides that, it's not even implemented now for
4065 * other things than (driver-core wise very simple) network devices.
4067 * We are currently about to change network renaming in udev to completely
4068 * disallow renaming of devices in the same namespace as the kernel uses,
4069 * because we can't solve the problems properly, that arise with swapping names
4070 * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
4071 * be allowed to some other name than eth[0-9]*, for the aforementioned
4074 * Make up a "real" name in the driver before you register anything, or add
4075 * some other attributes for userspace to find the device, or use udev to add
4076 * symlinks -- but never rename kernel devices later, it's a complete mess. We
4077 * don't even want to get into that and try to implement the missing pieces in
4078 * the core. We really have other pieces to fix in the driver core mess. :)
4080 int device_rename(struct device *dev, const char *new_name)
4082 struct kobject *kobj = &dev->kobj;
4083 char *old_device_name = NULL;
4086 dev = get_device(dev);
4090 dev_dbg(dev, "renaming to %s\n", new_name);
4092 old_device_name = kstrdup(dev_name(dev), GFP_KERNEL);
4093 if (!old_device_name) {
4099 error = sysfs_rename_link_ns(&dev->class->p->subsys.kobj,
4100 kobj, old_device_name,
4101 new_name, kobject_namespace(kobj));
4106 error = kobject_rename(kobj, new_name);
4113 kfree(old_device_name);
4117 EXPORT_SYMBOL_GPL(device_rename);
4119 static int device_move_class_links(struct device *dev,
4120 struct device *old_parent,
4121 struct device *new_parent)
4126 sysfs_remove_link(&dev->kobj, "device");
4128 error = sysfs_create_link(&dev->kobj, &new_parent->kobj,
4134 * device_move - moves a device to a new parent
4135 * @dev: the pointer to the struct device to be moved
4136 * @new_parent: the new parent of the device (can be NULL)
4137 * @dpm_order: how to reorder the dpm_list
4139 int device_move(struct device *dev, struct device *new_parent,
4140 enum dpm_order dpm_order)
4143 struct device *old_parent;
4144 struct kobject *new_parent_kobj;
4146 dev = get_device(dev);
4151 new_parent = get_device(new_parent);
4152 new_parent_kobj = get_device_parent(dev, new_parent);
4153 if (IS_ERR(new_parent_kobj)) {
4154 error = PTR_ERR(new_parent_kobj);
4155 put_device(new_parent);
4159 pr_debug("device: '%s': %s: moving to '%s'\n", dev_name(dev),
4160 __func__, new_parent ? dev_name(new_parent) : "<NULL>");
4161 error = kobject_move(&dev->kobj, new_parent_kobj);
4163 cleanup_glue_dir(dev, new_parent_kobj);
4164 put_device(new_parent);
4167 old_parent = dev->parent;
4168 dev->parent = new_parent;
4170 klist_remove(&dev->p->knode_parent);
4172 klist_add_tail(&dev->p->knode_parent,
4173 &new_parent->p->klist_children);
4174 set_dev_node(dev, dev_to_node(new_parent));
4178 error = device_move_class_links(dev, old_parent, new_parent);
4180 /* We ignore errors on cleanup since we're hosed anyway... */
4181 device_move_class_links(dev, new_parent, old_parent);
4182 if (!kobject_move(&dev->kobj, &old_parent->kobj)) {
4184 klist_remove(&dev->p->knode_parent);
4185 dev->parent = old_parent;
4187 klist_add_tail(&dev->p->knode_parent,
4188 &old_parent->p->klist_children);
4189 set_dev_node(dev, dev_to_node(old_parent));
4192 cleanup_glue_dir(dev, new_parent_kobj);
4193 put_device(new_parent);
4197 switch (dpm_order) {
4198 case DPM_ORDER_NONE:
4200 case DPM_ORDER_DEV_AFTER_PARENT:
4201 device_pm_move_after(dev, new_parent);
4202 devices_kset_move_after(dev, new_parent);
4204 case DPM_ORDER_PARENT_BEFORE_DEV:
4205 device_pm_move_before(new_parent, dev);
4206 devices_kset_move_before(new_parent, dev);
4208 case DPM_ORDER_DEV_LAST:
4209 device_pm_move_last(dev);
4210 devices_kset_move_last(dev);
4214 put_device(old_parent);
4220 EXPORT_SYMBOL_GPL(device_move);
4222 static int device_attrs_change_owner(struct device *dev, kuid_t kuid,
4225 struct kobject *kobj = &dev->kobj;
4226 struct class *class = dev->class;
4227 const struct device_type *type = dev->type;
4232 * Change the device groups of the device class for @dev to
4235 error = sysfs_groups_change_owner(kobj, class->dev_groups, kuid,
4243 * Change the device groups of the device type for @dev to
4246 error = sysfs_groups_change_owner(kobj, type->groups, kuid,
4252 /* Change the device groups of @dev to @kuid/@kgid. */
4253 error = sysfs_groups_change_owner(kobj, dev->groups, kuid, kgid);
4257 if (device_supports_offline(dev) && !dev->offline_disabled) {
4258 /* Change online device attributes of @dev to @kuid/@kgid. */
4259 error = sysfs_file_change_owner(kobj, dev_attr_online.attr.name,
4269 * device_change_owner - change the owner of an existing device.
4271 * @kuid: new owner's kuid
4272 * @kgid: new owner's kgid
4274 * This changes the owner of @dev and its corresponding sysfs entries to
4275 * @kuid/@kgid. This function closely mirrors how @dev was added via driver
4278 * Returns 0 on success or error code on failure.
4280 int device_change_owner(struct device *dev, kuid_t kuid, kgid_t kgid)
4283 struct kobject *kobj = &dev->kobj;
4285 dev = get_device(dev);
4290 * Change the kobject and the default attributes and groups of the
4291 * ktype associated with it to @kuid/@kgid.
4293 error = sysfs_change_owner(kobj, kuid, kgid);
4298 * Change the uevent file for @dev to the new owner. The uevent file
4299 * was created in a separate step when @dev got added and we mirror
4302 error = sysfs_file_change_owner(kobj, dev_attr_uevent.attr.name, kuid,
4308 * Change the device groups, the device groups associated with the
4309 * device class, and the groups associated with the device type of @dev
4312 error = device_attrs_change_owner(dev, kuid, kgid);
4316 error = dpm_sysfs_change_owner(dev, kuid, kgid);
4321 if (sysfs_deprecated && dev->class == &block_class)
4326 * Change the owner of the symlink located in the class directory of
4327 * the device class associated with @dev which points to the actual
4328 * directory entry for @dev to @kuid/@kgid. This ensures that the
4329 * symlink shows the same permissions as its target.
4331 error = sysfs_link_change_owner(&dev->class->p->subsys.kobj, &dev->kobj,
4332 dev_name(dev), kuid, kgid);
4340 EXPORT_SYMBOL_GPL(device_change_owner);
4343 * device_shutdown - call ->shutdown() on each device to shutdown.
4345 void device_shutdown(void)
4347 struct device *dev, *parent;
4349 wait_for_device_probe();
4350 device_block_probing();
4354 spin_lock(&devices_kset->list_lock);
4356 * Walk the devices list backward, shutting down each in turn.
4357 * Beware that device unplug events may also start pulling
4358 * devices offline, even as the system is shutting down.
4360 while (!list_empty(&devices_kset->list)) {
4361 dev = list_entry(devices_kset->list.prev, struct device,
4365 * hold reference count of device's parent to
4366 * prevent it from being freed because parent's
4367 * lock is to be held
4369 parent = get_device(dev->parent);
4372 * Make sure the device is off the kset list, in the
4373 * event that dev->*->shutdown() doesn't remove it.
4375 list_del_init(&dev->kobj.entry);
4376 spin_unlock(&devices_kset->list_lock);
4378 /* hold lock to avoid race with probe/release */
4380 device_lock(parent);
4383 /* Don't allow any more runtime suspends */
4384 pm_runtime_get_noresume(dev);
4385 pm_runtime_barrier(dev);
4387 if (dev->class && dev->class->shutdown_pre) {
4389 dev_info(dev, "shutdown_pre\n");
4390 dev->class->shutdown_pre(dev);
4392 if (dev->bus && dev->bus->shutdown) {
4394 dev_info(dev, "shutdown\n");
4395 dev->bus->shutdown(dev);
4396 } else if (dev->driver && dev->driver->shutdown) {
4398 dev_info(dev, "shutdown\n");
4399 dev->driver->shutdown(dev);
4404 device_unlock(parent);
4409 spin_lock(&devices_kset->list_lock);
4411 spin_unlock(&devices_kset->list_lock);
4415 * Device logging functions
4418 #ifdef CONFIG_PRINTK
4420 set_dev_info(const struct device *dev, struct dev_printk_info *dev_info)
4424 memset(dev_info, 0, sizeof(*dev_info));
4427 subsys = dev->class->name;
4429 subsys = dev->bus->name;
4433 strscpy(dev_info->subsystem, subsys, sizeof(dev_info->subsystem));
4436 * Add device identifier DEVICE=:
4440 * +sound:card0 subsystem:devname
4442 if (MAJOR(dev->devt)) {
4445 if (strcmp(subsys, "block") == 0)
4450 snprintf(dev_info->device, sizeof(dev_info->device),
4451 "%c%u:%u", c, MAJOR(dev->devt), MINOR(dev->devt));
4452 } else if (strcmp(subsys, "net") == 0) {
4453 struct net_device *net = to_net_dev(dev);
4455 snprintf(dev_info->device, sizeof(dev_info->device),
4456 "n%u", net->ifindex);
4458 snprintf(dev_info->device, sizeof(dev_info->device),
4459 "+%s:%s", subsys, dev_name(dev));
4463 int dev_vprintk_emit(int level, const struct device *dev,
4464 const char *fmt, va_list args)
4466 struct dev_printk_info dev_info;
4468 set_dev_info(dev, &dev_info);
4470 return vprintk_emit(0, level, &dev_info, fmt, args);
4472 EXPORT_SYMBOL(dev_vprintk_emit);
4474 int dev_printk_emit(int level, const struct device *dev, const char *fmt, ...)
4479 va_start(args, fmt);
4481 r = dev_vprintk_emit(level, dev, fmt, args);
4487 EXPORT_SYMBOL(dev_printk_emit);
4489 static void __dev_printk(const char *level, const struct device *dev,
4490 struct va_format *vaf)
4493 dev_printk_emit(level[1] - '0', dev, "%s %s: %pV",
4494 dev_driver_string(dev), dev_name(dev), vaf);
4496 printk("%s(NULL device *): %pV", level, vaf);
4499 void dev_printk(const char *level, const struct device *dev,
4500 const char *fmt, ...)
4502 struct va_format vaf;
4505 va_start(args, fmt);
4510 __dev_printk(level, dev, &vaf);
4514 EXPORT_SYMBOL(dev_printk);
4516 #define define_dev_printk_level(func, kern_level) \
4517 void func(const struct device *dev, const char *fmt, ...) \
4519 struct va_format vaf; \
4522 va_start(args, fmt); \
4527 __dev_printk(kern_level, dev, &vaf); \
4531 EXPORT_SYMBOL(func);
4533 define_dev_printk_level(_dev_emerg, KERN_EMERG);
4534 define_dev_printk_level(_dev_alert, KERN_ALERT);
4535 define_dev_printk_level(_dev_crit, KERN_CRIT);
4536 define_dev_printk_level(_dev_err, KERN_ERR);
4537 define_dev_printk_level(_dev_warn, KERN_WARNING);
4538 define_dev_printk_level(_dev_notice, KERN_NOTICE);
4539 define_dev_printk_level(_dev_info, KERN_INFO);
4544 * dev_err_probe - probe error check and log helper
4545 * @dev: the pointer to the struct device
4546 * @err: error value to test
4547 * @fmt: printf-style format string
4548 * @...: arguments as specified in the format string
4550 * This helper implements common pattern present in probe functions for error
4551 * checking: print debug or error message depending if the error value is
4552 * -EPROBE_DEFER and propagate error upwards.
4553 * In case of -EPROBE_DEFER it sets also defer probe reason, which can be
4554 * checked later by reading devices_deferred debugfs attribute.
4555 * It replaces code sequence::
4557 * if (err != -EPROBE_DEFER)
4558 * dev_err(dev, ...);
4560 * dev_dbg(dev, ...);
4565 * return dev_err_probe(dev, err, ...);
4570 int dev_err_probe(const struct device *dev, int err, const char *fmt, ...)
4572 struct va_format vaf;
4575 va_start(args, fmt);
4579 if (err != -EPROBE_DEFER) {
4580 dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
4582 device_set_deferred_probe_reason(dev, &vaf);
4583 dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf);
4590 EXPORT_SYMBOL_GPL(dev_err_probe);
4592 static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
4594 return fwnode && !IS_ERR(fwnode->secondary);
4598 * set_primary_fwnode - Change the primary firmware node of a given device.
4599 * @dev: Device to handle.
4600 * @fwnode: New primary firmware node of the device.
4602 * Set the device's firmware node pointer to @fwnode, but if a secondary
4603 * firmware node of the device is present, preserve it.
4605 * Valid fwnode cases are:
4606 * - primary --> secondary --> -ENODEV
4607 * - primary --> NULL
4608 * - secondary --> -ENODEV
4611 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
4613 struct device *parent = dev->parent;
4614 struct fwnode_handle *fn = dev->fwnode;
4617 if (fwnode_is_primary(fn))
4621 WARN_ON(fwnode->secondary);
4622 fwnode->secondary = fn;
4624 dev->fwnode = fwnode;
4626 if (fwnode_is_primary(fn)) {
4627 dev->fwnode = fn->secondary;
4628 /* Set fn->secondary = NULL, so fn remains the primary fwnode */
4629 if (!(parent && fn == parent->fwnode))
4630 fn->secondary = NULL;
4636 EXPORT_SYMBOL_GPL(set_primary_fwnode);
4639 * set_secondary_fwnode - Change the secondary firmware node of a given device.
4640 * @dev: Device to handle.
4641 * @fwnode: New secondary firmware node of the device.
4643 * If a primary firmware node of the device is present, set its secondary
4644 * pointer to @fwnode. Otherwise, set the device's firmware node pointer to
4647 void set_secondary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
4650 fwnode->secondary = ERR_PTR(-ENODEV);
4652 if (fwnode_is_primary(dev->fwnode))
4653 dev->fwnode->secondary = fwnode;
4655 dev->fwnode = fwnode;
4657 EXPORT_SYMBOL_GPL(set_secondary_fwnode);
4660 * device_set_of_node_from_dev - reuse device-tree node of another device
4661 * @dev: device whose device-tree node is being set
4662 * @dev2: device whose device-tree node is being reused
4664 * Takes another reference to the new device-tree node after first dropping
4665 * any reference held to the old node.
4667 void device_set_of_node_from_dev(struct device *dev, const struct device *dev2)
4669 of_node_put(dev->of_node);
4670 dev->of_node = of_node_get(dev2->of_node);
4671 dev->of_node_reused = true;
4673 EXPORT_SYMBOL_GPL(device_set_of_node_from_dev);
4675 int device_match_name(struct device *dev, const void *name)
4677 return sysfs_streq(dev_name(dev), name);
4679 EXPORT_SYMBOL_GPL(device_match_name);
4681 int device_match_of_node(struct device *dev, const void *np)
4683 return dev->of_node == np;
4685 EXPORT_SYMBOL_GPL(device_match_of_node);
4687 int device_match_fwnode(struct device *dev, const void *fwnode)
4689 return dev_fwnode(dev) == fwnode;
4691 EXPORT_SYMBOL_GPL(device_match_fwnode);
4693 int device_match_devt(struct device *dev, const void *pdevt)
4695 return dev->devt == *(dev_t *)pdevt;
4697 EXPORT_SYMBOL_GPL(device_match_devt);
4699 int device_match_acpi_dev(struct device *dev, const void *adev)
4701 return ACPI_COMPANION(dev) == adev;
4703 EXPORT_SYMBOL(device_match_acpi_dev);
4705 int device_match_any(struct device *dev, const void *unused)
4709 EXPORT_SYMBOL_GPL(device_match_any);