2 * bus.c - bus driver management
4 * Copyright (c) 2002-3 Patrick Mochel
5 * Copyright (c) 2002-3 Open Source Development Labs
6 * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
7 * Copyright (c) 2007 Novell Inc.
9 * This file is released under the GPLv2
13 #include <linux/device.h>
14 #include <linux/module.h>
15 #include <linux/errno.h>
16 #include <linux/init.h>
17 #include <linux/string.h>
19 #include "power/power.h"
21 #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
22 #define to_bus(obj) container_of(obj, struct bus_type_private, subsys.kobj)
25 * sysfs bindings for drivers
28 #define to_drv_attr(_attr) container_of(_attr, struct driver_attribute, attr)
31 static int __must_check bus_rescan_devices_helper(struct device *dev,
34 static struct bus_type *bus_get(struct bus_type *bus)
37 kset_get(&bus->p->subsys);
43 static void bus_put(struct bus_type *bus)
46 kset_put(&bus->p->subsys);
49 static ssize_t drv_attr_show(struct kobject *kobj, struct attribute *attr,
52 struct driver_attribute *drv_attr = to_drv_attr(attr);
53 struct driver_private *drv_priv = to_driver(kobj);
57 ret = drv_attr->show(drv_priv->driver, buf);
61 static ssize_t drv_attr_store(struct kobject *kobj, struct attribute *attr,
62 const char *buf, size_t count)
64 struct driver_attribute *drv_attr = to_drv_attr(attr);
65 struct driver_private *drv_priv = to_driver(kobj);
69 ret = drv_attr->store(drv_priv->driver, buf, count);
73 static struct sysfs_ops driver_sysfs_ops = {
74 .show = drv_attr_show,
75 .store = drv_attr_store,
78 static void driver_release(struct kobject *kobj)
80 struct driver_private *drv_priv = to_driver(kobj);
82 pr_debug("driver: '%s': %s\n", kobject_name(kobj), __func__);
86 static struct kobj_type driver_ktype = {
87 .sysfs_ops = &driver_sysfs_ops,
88 .release = driver_release,
92 * sysfs bindings for buses
94 static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
97 struct bus_attribute *bus_attr = to_bus_attr(attr);
98 struct bus_type_private *bus_priv = to_bus(kobj);
102 ret = bus_attr->show(bus_priv->bus, buf);
106 static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
107 const char *buf, size_t count)
109 struct bus_attribute *bus_attr = to_bus_attr(attr);
110 struct bus_type_private *bus_priv = to_bus(kobj);
114 ret = bus_attr->store(bus_priv->bus, buf, count);
118 static struct sysfs_ops bus_sysfs_ops = {
119 .show = bus_attr_show,
120 .store = bus_attr_store,
123 int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)
127 error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);
133 EXPORT_SYMBOL_GPL(bus_create_file);
135 void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)
138 sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);
142 EXPORT_SYMBOL_GPL(bus_remove_file);
144 static struct kobj_type bus_ktype = {
145 .sysfs_ops = &bus_sysfs_ops,
148 static int bus_uevent_filter(struct kset *kset, struct kobject *kobj)
150 struct kobj_type *ktype = get_ktype(kobj);
152 if (ktype == &bus_ktype)
157 static struct kset_uevent_ops bus_uevent_ops = {
158 .filter = bus_uevent_filter,
161 static struct kset *bus_kset;
164 #ifdef CONFIG_HOTPLUG
165 /* Manually detach a device from its associated driver. */
166 static ssize_t driver_unbind(struct device_driver *drv,
167 const char *buf, size_t count)
169 struct bus_type *bus = bus_get(drv->bus);
173 dev = bus_find_device_by_name(bus, NULL, buf);
174 if (dev && dev->driver == drv) {
175 if (dev->parent) /* Needed for USB */
176 down(&dev->parent->sem);
177 device_release_driver(dev);
179 up(&dev->parent->sem);
186 static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
189 * Manually attach a device to a driver.
190 * Note: the driver must want to bind to the device,
191 * it is not possible to override the driver's id table.
193 static ssize_t driver_bind(struct device_driver *drv,
194 const char *buf, size_t count)
196 struct bus_type *bus = bus_get(drv->bus);
200 dev = bus_find_device_by_name(bus, NULL, buf);
201 if (dev && dev->driver == NULL) {
202 if (dev->parent) /* Needed for USB */
203 down(&dev->parent->sem);
205 err = driver_probe_device(drv, dev);
208 up(&dev->parent->sem);
213 } else if (err == 0) {
214 /* driver didn't accept device */
222 static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
224 static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)
226 return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);
229 static ssize_t store_drivers_autoprobe(struct bus_type *bus,
230 const char *buf, size_t count)
233 bus->p->drivers_autoprobe = 0;
235 bus->p->drivers_autoprobe = 1;
239 static ssize_t store_drivers_probe(struct bus_type *bus,
240 const char *buf, size_t count)
244 dev = bus_find_device_by_name(bus, NULL, buf);
247 if (bus_rescan_devices_helper(dev, NULL) != 0)
253 static struct device *next_device(struct klist_iter *i)
255 struct klist_node *n = klist_next(i);
256 return n ? container_of(n, struct device, knode_bus) : NULL;
260 * bus_for_each_dev - device iterator.
262 * @start: device to start iterating from.
263 * @data: data for the callback.
264 * @fn: function to be called for each device.
266 * Iterate over @bus's list of devices, and call @fn for each,
267 * passing it @data. If @start is not NULL, we use that device to
268 * begin iterating from.
270 * We check the return of @fn each time. If it returns anything
271 * other than 0, we break out and return that value.
273 * NOTE: The device that returns a non-zero value is not retained
274 * in any way, nor is its refcount incremented. If the caller needs
275 * to retain this data, it should do, and increment the reference
276 * count in the supplied callback.
278 int bus_for_each_dev(struct bus_type *bus, struct device *start,
279 void *data, int (*fn)(struct device *, void *))
288 klist_iter_init_node(&bus->p->klist_devices, &i,
289 (start ? &start->knode_bus : NULL));
290 while ((dev = next_device(&i)) && !error)
291 error = fn(dev, data);
295 EXPORT_SYMBOL_GPL(bus_for_each_dev);
298 * bus_find_device - device iterator for locating a particular device.
300 * @start: Device to begin with
301 * @data: Data to pass to match function
302 * @match: Callback function to check device
304 * This is similar to the bus_for_each_dev() function above, but it
305 * returns a reference to a device that is 'found' for later use, as
306 * determined by the @match callback.
308 * The callback should return 0 if the device doesn't match and non-zero
309 * if it does. If the callback returns non-zero, this function will
310 * return to the caller and not iterate over any more devices.
312 struct device *bus_find_device(struct bus_type *bus,
313 struct device *start, void *data,
314 int (*match)(struct device *dev, void *data))
322 klist_iter_init_node(&bus->p->klist_devices, &i,
323 (start ? &start->knode_bus : NULL));
324 while ((dev = next_device(&i)))
325 if (match(dev, data) && get_device(dev))
330 EXPORT_SYMBOL_GPL(bus_find_device);
332 static int match_name(struct device *dev, void *data)
334 const char *name = data;
336 return sysfs_streq(name, dev_name(dev));
340 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
342 * @start: Device to begin with
343 * @name: name of the device to match
345 * This is similar to the bus_find_device() function above, but it handles
346 * searching by a name automatically, no need to write another strcmp matching
349 struct device *bus_find_device_by_name(struct bus_type *bus,
350 struct device *start, const char *name)
352 return bus_find_device(bus, start, (void *)name, match_name);
354 EXPORT_SYMBOL_GPL(bus_find_device_by_name);
356 static struct device_driver *next_driver(struct klist_iter *i)
358 struct klist_node *n = klist_next(i);
359 struct driver_private *drv_priv;
362 drv_priv = container_of(n, struct driver_private, knode_bus);
363 return drv_priv->driver;
369 * bus_for_each_drv - driver iterator
370 * @bus: bus we're dealing with.
371 * @start: driver to start iterating on.
372 * @data: data to pass to the callback.
373 * @fn: function to call for each driver.
375 * This is nearly identical to the device iterator above.
376 * We iterate over each driver that belongs to @bus, and call
377 * @fn for each. If @fn returns anything but 0, we break out
378 * and return it. If @start is not NULL, we use it as the head
381 * NOTE: we don't return the driver that returns a non-zero
382 * value, nor do we leave the reference count incremented for that
383 * driver. If the caller needs to know that info, it must set it
384 * in the callback. It must also be sure to increment the refcount
385 * so it doesn't disappear before returning to the caller.
387 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
388 void *data, int (*fn)(struct device_driver *, void *))
391 struct device_driver *drv;
397 klist_iter_init_node(&bus->p->klist_drivers, &i,
398 start ? &start->p->knode_bus : NULL);
399 while ((drv = next_driver(&i)) && !error)
400 error = fn(drv, data);
404 EXPORT_SYMBOL_GPL(bus_for_each_drv);
406 static int device_add_attrs(struct bus_type *bus, struct device *dev)
414 for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
415 error = device_create_file(dev, &bus->dev_attrs[i]);
418 device_remove_file(dev, &bus->dev_attrs[i]);
425 static void device_remove_attrs(struct bus_type *bus, struct device *dev)
429 if (bus->dev_attrs) {
430 for (i = 0; attr_name(bus->dev_attrs[i]); i++)
431 device_remove_file(dev, &bus->dev_attrs[i]);
435 #ifdef CONFIG_SYSFS_DEPRECATED
436 static int make_deprecated_bus_links(struct device *dev)
438 return sysfs_create_link(&dev->kobj,
439 &dev->bus->p->subsys.kobj, "bus");
442 static void remove_deprecated_bus_links(struct device *dev)
444 sysfs_remove_link(&dev->kobj, "bus");
447 static inline int make_deprecated_bus_links(struct device *dev) { return 0; }
448 static inline void remove_deprecated_bus_links(struct device *dev) { }
452 * bus_add_device - add device to bus
453 * @dev: device being added
455 * - Add the device to its bus's list of devices.
456 * - Create link to device's bus.
458 int bus_add_device(struct device *dev)
460 struct bus_type *bus = bus_get(dev->bus);
464 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
465 error = device_add_attrs(bus, dev);
468 error = sysfs_create_link(&bus->p->devices_kset->kobj,
469 &dev->kobj, dev_name(dev));
472 error = sysfs_create_link(&dev->kobj,
473 &dev->bus->p->subsys.kobj, "subsystem");
476 error = make_deprecated_bus_links(dev);
483 sysfs_remove_link(&dev->kobj, "subsystem");
485 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
487 device_remove_attrs(bus, dev);
494 * bus_attach_device - add device to bus
495 * @dev: device tried to attach to a driver
497 * - Add device to bus's list of devices.
498 * - Try to attach to driver.
500 void bus_attach_device(struct device *dev)
502 struct bus_type *bus = dev->bus;
506 if (bus->p->drivers_autoprobe)
507 ret = device_attach(dev);
510 klist_add_tail(&dev->knode_bus, &bus->p->klist_devices);
515 * bus_remove_device - remove device from bus
516 * @dev: device to be removed
518 * - Remove symlink from bus's directory.
519 * - Delete device from bus's list.
520 * - Detach from its driver.
521 * - Drop reference taken in bus_add_device().
523 void bus_remove_device(struct device *dev)
526 sysfs_remove_link(&dev->kobj, "subsystem");
527 remove_deprecated_bus_links(dev);
528 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
530 device_remove_attrs(dev->bus, dev);
531 if (klist_node_attached(&dev->knode_bus))
532 klist_del(&dev->knode_bus);
534 pr_debug("bus: '%s': remove device %s\n",
535 dev->bus->name, dev_name(dev));
536 device_release_driver(dev);
541 static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
546 if (bus->drv_attrs) {
547 for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
548 error = driver_create_file(drv, &bus->drv_attrs[i]);
557 driver_remove_file(drv, &bus->drv_attrs[i]);
561 static void driver_remove_attrs(struct bus_type *bus,
562 struct device_driver *drv)
566 if (bus->drv_attrs) {
567 for (i = 0; attr_name(bus->drv_attrs[i]); i++)
568 driver_remove_file(drv, &bus->drv_attrs[i]);
572 #ifdef CONFIG_HOTPLUG
574 * Thanks to drivers making their tables __devinit, we can't allow manual
575 * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
577 static int __must_check add_bind_files(struct device_driver *drv)
581 ret = driver_create_file(drv, &driver_attr_unbind);
583 ret = driver_create_file(drv, &driver_attr_bind);
585 driver_remove_file(drv, &driver_attr_unbind);
590 static void remove_bind_files(struct device_driver *drv)
592 driver_remove_file(drv, &driver_attr_bind);
593 driver_remove_file(drv, &driver_attr_unbind);
596 static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
597 static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
598 show_drivers_autoprobe, store_drivers_autoprobe);
600 static int add_probe_files(struct bus_type *bus)
604 retval = bus_create_file(bus, &bus_attr_drivers_probe);
608 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
610 bus_remove_file(bus, &bus_attr_drivers_probe);
615 static void remove_probe_files(struct bus_type *bus)
617 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
618 bus_remove_file(bus, &bus_attr_drivers_probe);
621 static inline int add_bind_files(struct device_driver *drv) { return 0; }
622 static inline void remove_bind_files(struct device_driver *drv) {}
623 static inline int add_probe_files(struct bus_type *bus) { return 0; }
624 static inline void remove_probe_files(struct bus_type *bus) {}
627 static ssize_t driver_uevent_store(struct device_driver *drv,
628 const char *buf, size_t count)
630 enum kobject_action action;
632 if (kobject_action_type(buf, count, &action) == 0)
633 kobject_uevent(&drv->p->kobj, action);
636 static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
639 * bus_add_driver - Add a driver to the bus.
642 int bus_add_driver(struct device_driver *drv)
644 struct bus_type *bus;
645 struct driver_private *priv;
648 bus = bus_get(drv->bus);
652 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
654 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
659 klist_init(&priv->klist_devices, NULL, NULL);
662 priv->kobj.kset = bus->p->drivers_kset;
663 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
668 if (drv->bus->p->drivers_autoprobe) {
669 error = driver_attach(drv);
673 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
674 module_add_driver(drv->owner, drv);
676 error = driver_create_file(drv, &driver_attr_uevent);
678 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
679 __func__, drv->name);
681 error = driver_add_attrs(bus, drv);
683 /* How the hell do we get out of this pickle? Give up */
684 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
685 __func__, drv->name);
687 error = add_bind_files(drv);
690 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
691 __func__, drv->name);
694 kobject_uevent(&priv->kobj, KOBJ_ADD);
697 kobject_put(&priv->kobj);
704 * bus_remove_driver - delete driver from bus's knowledge.
707 * Detach the driver from the devices it controls, and remove
708 * it from its bus's list of drivers. Finally, we drop the reference
709 * to the bus we took in bus_add_driver().
711 void bus_remove_driver(struct device_driver *drv)
716 remove_bind_files(drv);
717 driver_remove_attrs(drv->bus, drv);
718 driver_remove_file(drv, &driver_attr_uevent);
719 klist_remove(&drv->p->knode_bus);
720 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
722 module_remove_driver(drv);
723 kobject_put(&drv->p->kobj);
727 /* Helper for bus_rescan_devices's iter */
728 static int __must_check bus_rescan_devices_helper(struct device *dev,
734 if (dev->parent) /* Needed for USB */
735 down(&dev->parent->sem);
736 ret = device_attach(dev);
738 up(&dev->parent->sem);
740 return ret < 0 ? ret : 0;
744 * bus_rescan_devices - rescan devices on the bus for possible drivers
745 * @bus: the bus to scan.
747 * This function will look for devices on the bus with no driver
748 * attached and rescan it against existing drivers to see if it matches
749 * any by calling device_attach() for the unbound devices.
751 int bus_rescan_devices(struct bus_type *bus)
753 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
755 EXPORT_SYMBOL_GPL(bus_rescan_devices);
758 * device_reprobe - remove driver for a device and probe for a new driver
759 * @dev: the device to reprobe
761 * This function detaches the attached driver (if any) for the given
762 * device and restarts the driver probing process. It is intended
763 * to use if probing criteria changed during a devices lifetime and
764 * driver attachment should change accordingly.
766 int device_reprobe(struct device *dev)
769 if (dev->parent) /* Needed for USB */
770 down(&dev->parent->sem);
771 device_release_driver(dev);
773 up(&dev->parent->sem);
775 return bus_rescan_devices_helper(dev, NULL);
777 EXPORT_SYMBOL_GPL(device_reprobe);
780 * find_bus - locate bus by name.
781 * @name: name of bus.
783 * Call kset_find_obj() to iterate over list of buses to
784 * find a bus by name. Return bus if found.
786 * Note that kset_find_obj increments bus' reference count.
789 struct bus_type *find_bus(char *name)
791 struct kobject *k = kset_find_obj(bus_kset, name);
792 return k ? to_bus(k) : NULL;
798 * bus_add_attrs - Add default attributes for this bus.
799 * @bus: Bus that has just been registered.
802 static int bus_add_attrs(struct bus_type *bus)
807 if (bus->bus_attrs) {
808 for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
809 error = bus_create_file(bus, &bus->bus_attrs[i]);
818 bus_remove_file(bus, &bus->bus_attrs[i]);
822 static void bus_remove_attrs(struct bus_type *bus)
826 if (bus->bus_attrs) {
827 for (i = 0; attr_name(bus->bus_attrs[i]); i++)
828 bus_remove_file(bus, &bus->bus_attrs[i]);
832 static void klist_devices_get(struct klist_node *n)
834 struct device *dev = container_of(n, struct device, knode_bus);
839 static void klist_devices_put(struct klist_node *n)
841 struct device *dev = container_of(n, struct device, knode_bus);
846 static ssize_t bus_uevent_store(struct bus_type *bus,
847 const char *buf, size_t count)
849 enum kobject_action action;
851 if (kobject_action_type(buf, count, &action) == 0)
852 kobject_uevent(&bus->p->subsys.kobj, action);
855 static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
858 * bus_register - register a bus with the system.
861 * Once we have that, we registered the bus with the kobject
862 * infrastructure, then register the children subsystems it has:
863 * the devices and drivers that belong to the bus.
865 int bus_register(struct bus_type *bus)
868 struct bus_type_private *priv;
870 priv = kzalloc(sizeof(struct bus_type_private), GFP_KERNEL);
877 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
879 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
883 priv->subsys.kobj.kset = bus_kset;
884 priv->subsys.kobj.ktype = &bus_ktype;
885 priv->drivers_autoprobe = 1;
887 retval = kset_register(&priv->subsys);
891 retval = bus_create_file(bus, &bus_attr_uevent);
893 goto bus_uevent_fail;
895 priv->devices_kset = kset_create_and_add("devices", NULL,
897 if (!priv->devices_kset) {
899 goto bus_devices_fail;
902 priv->drivers_kset = kset_create_and_add("drivers", NULL,
904 if (!priv->drivers_kset) {
906 goto bus_drivers_fail;
909 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
910 klist_init(&priv->klist_drivers, NULL, NULL);
912 retval = add_probe_files(bus);
914 goto bus_probe_files_fail;
916 retval = bus_add_attrs(bus);
920 pr_debug("bus: '%s': registered\n", bus->name);
924 remove_probe_files(bus);
925 bus_probe_files_fail:
926 kset_unregister(bus->p->drivers_kset);
928 kset_unregister(bus->p->devices_kset);
930 bus_remove_file(bus, &bus_attr_uevent);
932 kset_unregister(&bus->p->subsys);
937 EXPORT_SYMBOL_GPL(bus_register);
940 * bus_unregister - remove a bus from the system
943 * Unregister the child subsystems and the bus itself.
944 * Finally, we call bus_put() to release the refcount
946 void bus_unregister(struct bus_type *bus)
948 pr_debug("bus: '%s': unregistering\n", bus->name);
949 bus_remove_attrs(bus);
950 remove_probe_files(bus);
951 kset_unregister(bus->p->drivers_kset);
952 kset_unregister(bus->p->devices_kset);
953 bus_remove_file(bus, &bus_attr_uevent);
954 kset_unregister(&bus->p->subsys);
957 EXPORT_SYMBOL_GPL(bus_unregister);
959 int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
961 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
963 EXPORT_SYMBOL_GPL(bus_register_notifier);
965 int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
967 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
969 EXPORT_SYMBOL_GPL(bus_unregister_notifier);
971 struct kset *bus_get_kset(struct bus_type *bus)
973 return &bus->p->subsys;
975 EXPORT_SYMBOL_GPL(bus_get_kset);
977 struct klist *bus_get_device_klist(struct bus_type *bus)
979 return &bus->p->klist_devices;
981 EXPORT_SYMBOL_GPL(bus_get_device_klist);
984 * Yes, this forcably breaks the klist abstraction temporarily. It
985 * just wants to sort the klist, not change reference counts and
986 * take/drop locks rapidly in the process. It does all this while
987 * holding the lock for the list, so objects can't otherwise be
988 * added/removed while we're swizzling.
990 static void device_insertion_sort_klist(struct device *a, struct list_head *list,
991 int (*compare)(const struct device *a,
992 const struct device *b))
994 struct list_head *pos;
995 struct klist_node *n;
998 list_for_each(pos, list) {
999 n = container_of(pos, struct klist_node, n_node);
1000 b = container_of(n, struct device, knode_bus);
1001 if (compare(a, b) <= 0) {
1002 list_move_tail(&a->knode_bus.n_node,
1003 &b->knode_bus.n_node);
1007 list_move_tail(&a->knode_bus.n_node, list);
1010 void bus_sort_breadthfirst(struct bus_type *bus,
1011 int (*compare)(const struct device *a,
1012 const struct device *b))
1014 LIST_HEAD(sorted_devices);
1015 struct list_head *pos, *tmp;
1016 struct klist_node *n;
1018 struct klist *device_klist;
1020 device_klist = bus_get_device_klist(bus);
1022 spin_lock(&device_klist->k_lock);
1023 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1024 n = container_of(pos, struct klist_node, n_node);
1025 dev = container_of(n, struct device, knode_bus);
1026 device_insertion_sort_klist(dev, &sorted_devices, compare);
1028 list_splice(&sorted_devices, &device_klist->k_list);
1029 spin_unlock(&device_klist->k_lock);
1031 EXPORT_SYMBOL_GPL(bus_sort_breadthfirst);
1033 int __init buses_init(void)
1035 bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);