3  * bus.c - bus driver management
41 static struct bus_type *bus_get(struct bus_type *bus)  in bus_get()  argument
43 	if (bus) {  in bus_get()
44 		kset_get(&bus->p->subsys);  in bus_get()
45 		return bus;  in bus_get()
50 static void bus_put(struct bus_type *bus)  in bus_put()  argument
52 	if (bus)  in bus_put()
53 		kset_put(&bus->p->subsys);  in bus_put()
109 		ret = bus_attr->show(subsys_priv->bus, buf);  in bus_attr_show()
121 		ret = bus_attr->store(subsys_priv->bus, buf, count);  in bus_attr_store()
130 int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)  in bus_create_file()  argument
133 	if (bus_get(bus)) {  in bus_create_file()
134 		error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);  in bus_create_file()
135 		bus_put(bus);  in bus_create_file()
142 void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)  in bus_remove_file()  argument
144 	if (bus_get(bus)) {  in bus_remove_file()
145 		sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);  in bus_remove_file()
146 		bus_put(bus);  in bus_remove_file()
154 	struct bus_type *bus = priv->bus;  in bus_release()  local
157 	bus->p = NULL;  in bus_release()
184 	struct bus_type *bus = bus_get(drv->bus);  in unbind_store()  local
188 	dev = bus_find_device_by_name(bus, NULL, buf);  in unbind_store()
194 	bus_put(bus);  in unbind_store()
207 	struct bus_type *bus = bus_get(drv->bus);  in bind_store()  local
211 	dev = bus_find_device_by_name(bus, NULL, buf);  in bind_store()
224 	bus_put(bus);  in bind_store()
229 static ssize_t drivers_autoprobe_show(struct bus_type *bus, char *buf)  in drivers_autoprobe_show()  argument
231 	return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);  in drivers_autoprobe_show()
234 static ssize_t drivers_autoprobe_store(struct bus_type *bus,  in drivers_autoprobe_store()  argument
238 		bus->p->drivers_autoprobe = 0;  in drivers_autoprobe_store()
240 		bus->p->drivers_autoprobe = 1;  in drivers_autoprobe_store()
244 static ssize_t drivers_probe_store(struct bus_type *bus,  in drivers_probe_store()  argument
250 	dev = bus_find_device_by_name(bus, NULL, buf);  in drivers_probe_store()
274  * @bus: bus type.
279  * Iterate over @bus's list of devices, and call @fn for each,
291 int bus_for_each_dev(struct bus_type *bus, struct device *start,  in bus_for_each_dev()  argument
298 	if (!bus || !bus->p)  in bus_for_each_dev()
301 	klist_iter_init_node(&bus->p->klist_devices, &i,  in bus_for_each_dev()
312  * @bus: bus type
325 struct device *bus_find_device(struct bus_type *bus,  in bus_find_device()  argument
332 	if (!bus || !bus->p)  in bus_find_device()
335 	klist_iter_init_node(&bus->p->klist_devices, &i,  in bus_find_device()
400  * @bus: bus we're dealing with.
406  * We iterate over each driver that belongs to @bus, and call
417 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,  in bus_for_each_drv()  argument
424 	if (!bus)  in bus_for_each_drv()
427 	klist_iter_init_node(&bus->p->klist_drivers, &i,  in bus_for_each_drv()
437  * bus_add_device - add device to bus
440  * - Add device's bus attributes.
441  * - Create links to device's bus.
442  * - Add the device to its bus's list of devices.
446 	struct bus_type *bus = bus_get(dev->bus);  in bus_add_device()  local
449 	if (bus) {  in bus_add_device()
450 		pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));  in bus_add_device()
451 		error = device_add_groups(dev, bus->dev_groups);  in bus_add_device()
454 		error = sysfs_create_link(&bus->p->devices_kset->kobj,  in bus_add_device()
459 				&dev->bus->p->subsys.kobj, "subsystem");  in bus_add_device()
462 		klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);  in bus_add_device()
467 	sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));  in bus_add_device()
469 	device_remove_groups(dev, bus->dev_groups);  in bus_add_device()
471 	bus_put(dev->bus);  in bus_add_device()
479  * - Automatically probe for a driver if the bus allows it.
483 	struct bus_type *bus = dev->bus;  in bus_probe_device()  local
486 	if (!bus)  in bus_probe_device()
489 	if (bus->p->drivers_autoprobe)  in bus_probe_device()
492 	mutex_lock(&bus->p->mutex);  in bus_probe_device()
493 	list_for_each_entry(sif, &bus->p->interfaces, node)  in bus_probe_device()
496 	mutex_unlock(&bus->p->mutex);  in bus_probe_device()
500  * bus_remove_device - remove device from bus
504  * - Remove symlink from bus' directory.
505  * - Delete device from bus's list.
511 	struct bus_type *bus = dev->bus;  in bus_remove_device()  local
514 	if (!bus)  in bus_remove_device()
517 	mutex_lock(&bus->p->mutex);  in bus_remove_device()
518 	list_for_each_entry(sif, &bus->p->interfaces, node)  in bus_remove_device()
521 	mutex_unlock(&bus->p->mutex);  in bus_remove_device()
524 	sysfs_remove_link(&dev->bus->p->devices_kset->kobj,  in bus_remove_device()
526 	device_remove_groups(dev, dev->bus->dev_groups);  in bus_remove_device()
530 	pr_debug("bus: '%s': remove device %s\n",  in bus_remove_device()
531 		 dev->bus->name, dev_name(dev));  in bus_remove_device()
533 	bus_put(dev->bus);  in bus_remove_device()
558 static int add_probe_files(struct bus_type *bus)  in add_probe_files()  argument
562 	retval = bus_create_file(bus, &bus_attr_drivers_probe);  in add_probe_files()
566 	retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);  in add_probe_files()
568 		bus_remove_file(bus, &bus_attr_drivers_probe);  in add_probe_files()
573 static void remove_probe_files(struct bus_type *bus)  in remove_probe_files()  argument
575 	bus_remove_file(bus, &bus_attr_drivers_autoprobe);  in remove_probe_files()
576 	bus_remove_file(bus, &bus_attr_drivers_probe);  in remove_probe_files()
590  * bus_add_driver - Add a driver to the bus.
595 	struct bus_type *bus;  in bus_add_driver()  local
599 	bus = bus_get(drv->bus);  in bus_add_driver()
600 	if (!bus)  in bus_add_driver()
603 	pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);  in bus_add_driver()
613 	priv->kobj.kset = bus->p->drivers_kset;  in bus_add_driver()
619 	klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);  in bus_add_driver()
620 	if (drv->bus->p->drivers_autoprobe) {  in bus_add_driver()
632 	error = driver_add_groups(drv, bus->drv_groups);  in bus_add_driver()
655 	bus_put(bus);  in bus_add_driver()
660  * bus_remove_driver - delete driver from bus's knowledge.
664  * it from its bus's list of drivers. Finally, we drop the reference
665  * to the bus we took in bus_add_driver().
669 	if (!drv->bus)  in bus_remove_driver()
674 	driver_remove_groups(drv, drv->bus->drv_groups);  in bus_remove_driver()
677 	pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);  in bus_remove_driver()
681 	bus_put(drv->bus);  in bus_remove_driver()
691 		if (dev->parent && dev->bus->need_parent_lock)  in bus_rescan_devices_helper()
694 		if (dev->parent && dev->bus->need_parent_lock)  in bus_rescan_devices_helper()
701  * bus_rescan_devices - rescan devices on the bus for possible drivers
702  * @bus: the bus to scan.
704  * This function will look for devices on the bus with no driver
708 int bus_rescan_devices(struct bus_type *bus)  in bus_rescan_devices()  argument
710 	return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);  in bus_rescan_devices()
732  * find_bus - locate bus by name.
733  * @name: name of bus.
736  * find a bus by name. Return bus if found.
738  * Note that kset_find_obj increments bus' reference count.
748 static int bus_add_groups(struct bus_type *bus,  in bus_add_groups()  argument
751 	return sysfs_create_groups(&bus->p->subsys.kobj, groups);  in bus_add_groups()
754 static void bus_remove_groups(struct bus_type *bus,  in bus_remove_groups()  argument
757 	sysfs_remove_groups(&bus->p->subsys.kobj, groups);  in bus_remove_groups()
776 static ssize_t bus_uevent_store(struct bus_type *bus,  in bus_uevent_store()  argument
781 	rc = kobject_synth_uevent(&bus->p->subsys.kobj, buf, count);  in bus_uevent_store()
795  * @bus: bus to register
797  * Once we have that, we register the bus with the kobject
801 int bus_register(struct bus_type *bus)  in bus_register()  argument
805 	struct lock_class_key *key = &bus->lock_key;  in bus_register()
811 	priv->bus = bus;  in bus_register()
812 	bus->p = priv;  in bus_register()
816 	retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);  in bus_register()
828 	retval = bus_create_file(bus, &bus_attr_uevent);  in bus_register()
851 	retval = add_probe_files(bus);  in bus_register()
855 	retval = bus_add_groups(bus, bus->bus_groups);  in bus_register()
859 	pr_debug("bus: '%s': registered\n", bus->name);  in bus_register()
863 	remove_probe_files(bus);  in bus_register()
865 	kset_unregister(bus->p->drivers_kset);  in bus_register()
867 	kset_unregister(bus->p->devices_kset);  in bus_register()
869 	bus_remove_file(bus, &bus_attr_uevent);  in bus_register()
871 	kset_unregister(&bus->p->subsys);  in bus_register()
873 	kfree(bus->p);  in bus_register()
874 	bus->p = NULL;  in bus_register()
880  * bus_unregister - remove a bus from the system
881  * @bus: bus.
883  * Unregister the child subsystems and the bus itself.
886 void bus_unregister(struct bus_type *bus)  in bus_unregister()  argument
888 	pr_debug("bus: '%s': unregistering\n", bus->name);  in bus_unregister()
889 	if (bus->dev_root)  in bus_unregister()
890 		device_unregister(bus->dev_root);  in bus_unregister()
891 	bus_remove_groups(bus, bus->bus_groups);  in bus_unregister()
892 	remove_probe_files(bus);  in bus_unregister()
893 	kset_unregister(bus->p->drivers_kset);  in bus_unregister()
894 	kset_unregister(bus->p->devices_kset);  in bus_unregister()
895 	bus_remove_file(bus, &bus_attr_uevent);  in bus_unregister()
896 	kset_unregister(&bus->p->subsys);  in bus_unregister()
900 int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)  in bus_register_notifier()  argument
902 	return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);  in bus_register_notifier()
906 int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)  in bus_unregister_notifier()  argument
908 	return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);  in bus_unregister_notifier()
912 struct kset *bus_get_kset(struct bus_type *bus)  in bus_get_kset()  argument
914 	return &bus->p->subsys;  in bus_get_kset()
918 struct klist *bus_get_device_klist(struct bus_type *bus)  in bus_get_device_klist()  argument
920 	return &bus->p->klist_devices;  in bus_get_device_klist()
951 void bus_sort_breadthfirst(struct bus_type *bus,  in bus_sort_breadthfirst()  argument
961 	device_klist = bus_get_device_klist(bus);  in bus_sort_breadthfirst()
1189 	bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);  in buses_init()