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/slab.h>
17 #include <linux/init.h>
18 #include <linux/string.h>
20 #include "power/power.h"
22 #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
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 const 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 subsys_private *subsys_priv = to_subsys_private(kobj);
102 ret = bus_attr->show(subsys_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 subsys_private *subsys_priv = to_subsys_private(kobj);
114 ret = bus_attr->store(subsys_priv->bus, buf, count);
118 static const 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 const 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 device_lock(dev->parent);
177 device_release_driver(dev);
179 device_unlock(dev->parent);
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 && driver_match_device(drv, dev)) {
202 if (dev->parent) /* Needed for USB */
203 device_lock(dev->parent);
205 err = driver_probe_device(drv, dev);
208 device_unlock(dev->parent);
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)
245 dev = bus_find_device_by_name(bus, NULL, buf);
248 if (bus_rescan_devices_helper(dev, NULL) == 0)
255 static struct device *next_device(struct klist_iter *i)
257 struct klist_node *n = klist_next(i);
258 struct device *dev = NULL;
259 struct device_private *dev_prv;
262 dev_prv = to_device_private_bus(n);
263 dev = dev_prv->device;
269 * bus_for_each_dev - device iterator.
271 * @start: device to start iterating from.
272 * @data: data for the callback.
273 * @fn: function to be called for each device.
275 * Iterate over @bus's list of devices, and call @fn for each,
276 * passing it @data. If @start is not NULL, we use that device to
277 * begin iterating from.
279 * We check the return of @fn each time. If it returns anything
280 * other than 0, we break out and return that value.
282 * NOTE: The device that returns a non-zero value is not retained
283 * in any way, nor is its refcount incremented. If the caller needs
284 * to retain this data, it should do so, and increment the reference
285 * count in the supplied callback.
287 int bus_for_each_dev(struct bus_type *bus, struct device *start,
288 void *data, int (*fn)(struct device *, void *))
297 klist_iter_init_node(&bus->p->klist_devices, &i,
298 (start ? &start->p->knode_bus : NULL));
299 while ((dev = next_device(&i)) && !error)
300 error = fn(dev, data);
304 EXPORT_SYMBOL_GPL(bus_for_each_dev);
307 * bus_find_device - device iterator for locating a particular device.
309 * @start: Device to begin with
310 * @data: Data to pass to match function
311 * @match: Callback function to check device
313 * This is similar to the bus_for_each_dev() function above, but it
314 * returns a reference to a device that is 'found' for later use, as
315 * determined by the @match callback.
317 * The callback should return 0 if the device doesn't match and non-zero
318 * if it does. If the callback returns non-zero, this function will
319 * return to the caller and not iterate over any more devices.
321 struct device *bus_find_device(struct bus_type *bus,
322 struct device *start, void *data,
323 int (*match)(struct device *dev, void *data))
331 klist_iter_init_node(&bus->p->klist_devices, &i,
332 (start ? &start->p->knode_bus : NULL));
333 while ((dev = next_device(&i)))
334 if (match(dev, data) && get_device(dev))
339 EXPORT_SYMBOL_GPL(bus_find_device);
341 static int match_name(struct device *dev, void *data)
343 const char *name = data;
345 return sysfs_streq(name, dev_name(dev));
349 * bus_find_device_by_name - device iterator for locating a particular device of a specific name
351 * @start: Device to begin with
352 * @name: name of the device to match
354 * This is similar to the bus_find_device() function above, but it handles
355 * searching by a name automatically, no need to write another strcmp matching
358 struct device *bus_find_device_by_name(struct bus_type *bus,
359 struct device *start, const char *name)
361 return bus_find_device(bus, start, (void *)name, match_name);
363 EXPORT_SYMBOL_GPL(bus_find_device_by_name);
365 static struct device_driver *next_driver(struct klist_iter *i)
367 struct klist_node *n = klist_next(i);
368 struct driver_private *drv_priv;
371 drv_priv = container_of(n, struct driver_private, knode_bus);
372 return drv_priv->driver;
378 * bus_for_each_drv - driver iterator
379 * @bus: bus we're dealing with.
380 * @start: driver to start iterating on.
381 * @data: data to pass to the callback.
382 * @fn: function to call for each driver.
384 * This is nearly identical to the device iterator above.
385 * We iterate over each driver that belongs to @bus, and call
386 * @fn for each. If @fn returns anything but 0, we break out
387 * and return it. If @start is not NULL, we use it as the head
390 * NOTE: we don't return the driver that returns a non-zero
391 * value, nor do we leave the reference count incremented for that
392 * driver. If the caller needs to know that info, it must set it
393 * in the callback. It must also be sure to increment the refcount
394 * so it doesn't disappear before returning to the caller.
396 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
397 void *data, int (*fn)(struct device_driver *, void *))
400 struct device_driver *drv;
406 klist_iter_init_node(&bus->p->klist_drivers, &i,
407 start ? &start->p->knode_bus : NULL);
408 while ((drv = next_driver(&i)) && !error)
409 error = fn(drv, data);
413 EXPORT_SYMBOL_GPL(bus_for_each_drv);
415 static int device_add_attrs(struct bus_type *bus, struct device *dev)
423 for (i = 0; attr_name(bus->dev_attrs[i]); i++) {
424 error = device_create_file(dev, &bus->dev_attrs[i]);
427 device_remove_file(dev, &bus->dev_attrs[i]);
434 static void device_remove_attrs(struct bus_type *bus, struct device *dev)
438 if (bus->dev_attrs) {
439 for (i = 0; attr_name(bus->dev_attrs[i]); i++)
440 device_remove_file(dev, &bus->dev_attrs[i]);
445 * bus_add_device - add device to bus
446 * @dev: device being added
448 * - Add device's bus attributes.
449 * - Create links to device's bus.
450 * - Add the device to its bus's list of devices.
452 int bus_add_device(struct device *dev)
454 struct bus_type *bus = bus_get(dev->bus);
458 pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));
459 error = device_add_attrs(bus, dev);
462 error = sysfs_create_link(&bus->p->devices_kset->kobj,
463 &dev->kobj, dev_name(dev));
466 error = sysfs_create_link(&dev->kobj,
467 &dev->bus->p->subsys.kobj, "subsystem");
470 klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);
475 sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));
477 device_remove_attrs(bus, dev);
484 * bus_probe_device - probe drivers for a new device
485 * @dev: device to probe
487 * - Automatically probe for a driver if the bus allows it.
489 void bus_probe_device(struct device *dev)
491 struct bus_type *bus = dev->bus;
494 if (bus && bus->p->drivers_autoprobe) {
495 ret = device_attach(dev);
501 * bus_remove_device - remove device from bus
502 * @dev: device to be removed
504 * - Remove symlink from bus's directory.
505 * - Delete device from bus's list.
506 * - Detach from its driver.
507 * - Drop reference taken in bus_add_device().
509 void bus_remove_device(struct device *dev)
512 sysfs_remove_link(&dev->kobj, "subsystem");
513 sysfs_remove_link(&dev->bus->p->devices_kset->kobj,
515 device_remove_attrs(dev->bus, dev);
516 if (klist_node_attached(&dev->p->knode_bus))
517 klist_del(&dev->p->knode_bus);
519 pr_debug("bus: '%s': remove device %s\n",
520 dev->bus->name, dev_name(dev));
521 device_release_driver(dev);
526 static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)
531 if (bus->drv_attrs) {
532 for (i = 0; attr_name(bus->drv_attrs[i]); i++) {
533 error = driver_create_file(drv, &bus->drv_attrs[i]);
542 driver_remove_file(drv, &bus->drv_attrs[i]);
546 static void driver_remove_attrs(struct bus_type *bus,
547 struct device_driver *drv)
551 if (bus->drv_attrs) {
552 for (i = 0; attr_name(bus->drv_attrs[i]); i++)
553 driver_remove_file(drv, &bus->drv_attrs[i]);
557 #ifdef CONFIG_HOTPLUG
559 * Thanks to drivers making their tables __devinit, we can't allow manual
560 * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
562 static int __must_check add_bind_files(struct device_driver *drv)
566 ret = driver_create_file(drv, &driver_attr_unbind);
568 ret = driver_create_file(drv, &driver_attr_bind);
570 driver_remove_file(drv, &driver_attr_unbind);
575 static void remove_bind_files(struct device_driver *drv)
577 driver_remove_file(drv, &driver_attr_bind);
578 driver_remove_file(drv, &driver_attr_unbind);
581 static BUS_ATTR(drivers_probe, S_IWUSR, NULL, store_drivers_probe);
582 static BUS_ATTR(drivers_autoprobe, S_IWUSR | S_IRUGO,
583 show_drivers_autoprobe, store_drivers_autoprobe);
585 static int add_probe_files(struct bus_type *bus)
589 retval = bus_create_file(bus, &bus_attr_drivers_probe);
593 retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);
595 bus_remove_file(bus, &bus_attr_drivers_probe);
600 static void remove_probe_files(struct bus_type *bus)
602 bus_remove_file(bus, &bus_attr_drivers_autoprobe);
603 bus_remove_file(bus, &bus_attr_drivers_probe);
606 static inline int add_bind_files(struct device_driver *drv) { return 0; }
607 static inline void remove_bind_files(struct device_driver *drv) {}
608 static inline int add_probe_files(struct bus_type *bus) { return 0; }
609 static inline void remove_probe_files(struct bus_type *bus) {}
612 static ssize_t driver_uevent_store(struct device_driver *drv,
613 const char *buf, size_t count)
615 enum kobject_action action;
617 if (kobject_action_type(buf, count, &action) == 0)
618 kobject_uevent(&drv->p->kobj, action);
621 static DRIVER_ATTR(uevent, S_IWUSR, NULL, driver_uevent_store);
624 * bus_add_driver - Add a driver to the bus.
627 int bus_add_driver(struct device_driver *drv)
629 struct bus_type *bus;
630 struct driver_private *priv;
633 bus = bus_get(drv->bus);
637 pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);
639 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
644 klist_init(&priv->klist_devices, NULL, NULL);
647 priv->kobj.kset = bus->p->drivers_kset;
648 error = kobject_init_and_add(&priv->kobj, &driver_ktype, NULL,
653 if (drv->bus->p->drivers_autoprobe) {
654 error = driver_attach(drv);
658 klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);
659 module_add_driver(drv->owner, drv);
661 error = driver_create_file(drv, &driver_attr_uevent);
663 printk(KERN_ERR "%s: uevent attr (%s) failed\n",
664 __func__, drv->name);
666 error = driver_add_attrs(bus, drv);
668 /* How the hell do we get out of this pickle? Give up */
669 printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n",
670 __func__, drv->name);
673 if (!drv->suppress_bind_attrs) {
674 error = add_bind_files(drv);
677 printk(KERN_ERR "%s: add_bind_files(%s) failed\n",
678 __func__, drv->name);
682 kobject_uevent(&priv->kobj, KOBJ_ADD);
686 kobject_put(&priv->kobj);
695 * bus_remove_driver - delete driver from bus's knowledge.
698 * Detach the driver from the devices it controls, and remove
699 * it from its bus's list of drivers. Finally, we drop the reference
700 * to the bus we took in bus_add_driver().
702 void bus_remove_driver(struct device_driver *drv)
707 if (!drv->suppress_bind_attrs)
708 remove_bind_files(drv);
709 driver_remove_attrs(drv->bus, drv);
710 driver_remove_file(drv, &driver_attr_uevent);
711 klist_remove(&drv->p->knode_bus);
712 pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);
714 module_remove_driver(drv);
715 kobject_put(&drv->p->kobj);
719 /* Helper for bus_rescan_devices's iter */
720 static int __must_check bus_rescan_devices_helper(struct device *dev,
726 if (dev->parent) /* Needed for USB */
727 device_lock(dev->parent);
728 ret = device_attach(dev);
730 device_unlock(dev->parent);
732 return ret < 0 ? ret : 0;
736 * bus_rescan_devices - rescan devices on the bus for possible drivers
737 * @bus: the bus to scan.
739 * This function will look for devices on the bus with no driver
740 * attached and rescan it against existing drivers to see if it matches
741 * any by calling device_attach() for the unbound devices.
743 int bus_rescan_devices(struct bus_type *bus)
745 return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
747 EXPORT_SYMBOL_GPL(bus_rescan_devices);
750 * device_reprobe - remove driver for a device and probe for a new driver
751 * @dev: the device to reprobe
753 * This function detaches the attached driver (if any) for the given
754 * device and restarts the driver probing process. It is intended
755 * to use if probing criteria changed during a devices lifetime and
756 * driver attachment should change accordingly.
758 int device_reprobe(struct device *dev)
761 if (dev->parent) /* Needed for USB */
762 device_lock(dev->parent);
763 device_release_driver(dev);
765 device_unlock(dev->parent);
767 return bus_rescan_devices_helper(dev, NULL);
769 EXPORT_SYMBOL_GPL(device_reprobe);
772 * find_bus - locate bus by name.
773 * @name: name of bus.
775 * Call kset_find_obj() to iterate over list of buses to
776 * find a bus by name. Return bus if found.
778 * Note that kset_find_obj increments bus' reference count.
781 struct bus_type *find_bus(char *name)
783 struct kobject *k = kset_find_obj(bus_kset, name);
784 return k ? to_bus(k) : NULL;
790 * bus_add_attrs - Add default attributes for this bus.
791 * @bus: Bus that has just been registered.
794 static int bus_add_attrs(struct bus_type *bus)
799 if (bus->bus_attrs) {
800 for (i = 0; attr_name(bus->bus_attrs[i]); i++) {
801 error = bus_create_file(bus, &bus->bus_attrs[i]);
810 bus_remove_file(bus, &bus->bus_attrs[i]);
814 static void bus_remove_attrs(struct bus_type *bus)
818 if (bus->bus_attrs) {
819 for (i = 0; attr_name(bus->bus_attrs[i]); i++)
820 bus_remove_file(bus, &bus->bus_attrs[i]);
824 static void klist_devices_get(struct klist_node *n)
826 struct device_private *dev_prv = to_device_private_bus(n);
827 struct device *dev = dev_prv->device;
832 static void klist_devices_put(struct klist_node *n)
834 struct device_private *dev_prv = to_device_private_bus(n);
835 struct device *dev = dev_prv->device;
840 static ssize_t bus_uevent_store(struct bus_type *bus,
841 const char *buf, size_t count)
843 enum kobject_action action;
845 if (kobject_action_type(buf, count, &action) == 0)
846 kobject_uevent(&bus->p->subsys.kobj, action);
849 static BUS_ATTR(uevent, S_IWUSR, NULL, bus_uevent_store);
852 * bus_register - register a bus with the system.
855 * Once we have that, we registered the bus with the kobject
856 * infrastructure, then register the children subsystems it has:
857 * the devices and drivers that belong to the bus.
859 int bus_register(struct bus_type *bus)
862 struct subsys_private *priv;
864 priv = kzalloc(sizeof(struct subsys_private), GFP_KERNEL);
871 BLOCKING_INIT_NOTIFIER_HEAD(&priv->bus_notifier);
873 retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);
877 priv->subsys.kobj.kset = bus_kset;
878 priv->subsys.kobj.ktype = &bus_ktype;
879 priv->drivers_autoprobe = 1;
881 retval = kset_register(&priv->subsys);
885 retval = bus_create_file(bus, &bus_attr_uevent);
887 goto bus_uevent_fail;
889 priv->devices_kset = kset_create_and_add("devices", NULL,
891 if (!priv->devices_kset) {
893 goto bus_devices_fail;
896 priv->drivers_kset = kset_create_and_add("drivers", NULL,
898 if (!priv->drivers_kset) {
900 goto bus_drivers_fail;
903 klist_init(&priv->klist_devices, klist_devices_get, klist_devices_put);
904 klist_init(&priv->klist_drivers, NULL, NULL);
906 retval = add_probe_files(bus);
908 goto bus_probe_files_fail;
910 retval = bus_add_attrs(bus);
914 pr_debug("bus: '%s': registered\n", bus->name);
918 remove_probe_files(bus);
919 bus_probe_files_fail:
920 kset_unregister(bus->p->drivers_kset);
922 kset_unregister(bus->p->devices_kset);
924 bus_remove_file(bus, &bus_attr_uevent);
926 kset_unregister(&bus->p->subsys);
932 EXPORT_SYMBOL_GPL(bus_register);
935 * bus_unregister - remove a bus from the system
938 * Unregister the child subsystems and the bus itself.
939 * Finally, we call bus_put() to release the refcount
941 void bus_unregister(struct bus_type *bus)
943 pr_debug("bus: '%s': unregistering\n", bus->name);
944 bus_remove_attrs(bus);
945 remove_probe_files(bus);
946 kset_unregister(bus->p->drivers_kset);
947 kset_unregister(bus->p->devices_kset);
948 bus_remove_file(bus, &bus_attr_uevent);
949 kset_unregister(&bus->p->subsys);
953 EXPORT_SYMBOL_GPL(bus_unregister);
955 int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)
957 return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);
959 EXPORT_SYMBOL_GPL(bus_register_notifier);
961 int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)
963 return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);
965 EXPORT_SYMBOL_GPL(bus_unregister_notifier);
967 struct kset *bus_get_kset(struct bus_type *bus)
969 return &bus->p->subsys;
971 EXPORT_SYMBOL_GPL(bus_get_kset);
973 struct klist *bus_get_device_klist(struct bus_type *bus)
975 return &bus->p->klist_devices;
977 EXPORT_SYMBOL_GPL(bus_get_device_klist);
980 * Yes, this forcibly breaks the klist abstraction temporarily. It
981 * just wants to sort the klist, not change reference counts and
982 * take/drop locks rapidly in the process. It does all this while
983 * holding the lock for the list, so objects can't otherwise be
984 * added/removed while we're swizzling.
986 static void device_insertion_sort_klist(struct device *a, struct list_head *list,
987 int (*compare)(const struct device *a,
988 const struct device *b))
990 struct list_head *pos;
991 struct klist_node *n;
992 struct device_private *dev_prv;
995 list_for_each(pos, list) {
996 n = container_of(pos, struct klist_node, n_node);
997 dev_prv = to_device_private_bus(n);
999 if (compare(a, b) <= 0) {
1000 list_move_tail(&a->p->knode_bus.n_node,
1001 &b->p->knode_bus.n_node);
1005 list_move_tail(&a->p->knode_bus.n_node, list);
1008 void bus_sort_breadthfirst(struct bus_type *bus,
1009 int (*compare)(const struct device *a,
1010 const struct device *b))
1012 LIST_HEAD(sorted_devices);
1013 struct list_head *pos, *tmp;
1014 struct klist_node *n;
1015 struct device_private *dev_prv;
1017 struct klist *device_klist;
1019 device_klist = bus_get_device_klist(bus);
1021 spin_lock(&device_klist->k_lock);
1022 list_for_each_safe(pos, tmp, &device_klist->k_list) {
1023 n = container_of(pos, struct klist_node, n_node);
1024 dev_prv = to_device_private_bus(n);
1025 dev = dev_prv->device;
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);