2  * bus.c - bus driver management
39 static struct bus_type *bus_get(struct bus_type *bus)  in bus_get()  argument
41 	if (bus) {  in bus_get()
42 		kset_get(&bus->p->subsys);  in bus_get()
43 		return bus;  in bus_get()
48 static void bus_put(struct bus_type *bus)  in bus_put()  argument
50 	if (bus)  in bus_put()
51 		kset_put(&bus->p->subsys);  in bus_put()
107 		ret = bus_attr->show(subsys_priv->bus, buf);  in bus_attr_show()
119 		ret = bus_attr->store(subsys_priv->bus, buf, count);  in bus_attr_store()
128 int bus_create_file(struct bus_type *bus, struct bus_attribute *attr)  in bus_create_file()  argument
131 	if (bus_get(bus)) {  in bus_create_file()
132 		error = sysfs_create_file(&bus->p->subsys.kobj, &attr->attr);  in bus_create_file()
133 		bus_put(bus);  in bus_create_file()
140 void bus_remove_file(struct bus_type *bus, struct bus_attribute *attr)  in bus_remove_file()  argument
142 	if (bus_get(bus)) {  in bus_remove_file()
143 		sysfs_remove_file(&bus->p->subsys.kobj, &attr->attr);  in bus_remove_file()
144 		bus_put(bus);  in bus_remove_file()
174 	struct bus_type *bus = bus_get(drv->bus);  in driver_unbind()  local
178 	dev = bus_find_device_by_name(bus, NULL, buf);  in driver_unbind()
188 	bus_put(bus);  in driver_unbind()
201 	struct bus_type *bus = bus_get(drv->bus);  in driver_bind()  local
205 	dev = bus_find_device_by_name(bus, NULL, buf);  in driver_bind()
224 	bus_put(bus);  in driver_bind()
229 static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf)  in show_drivers_autoprobe()  argument
231 	return sprintf(buf, "%d\n", bus->p->drivers_autoprobe);  in show_drivers_autoprobe()
234 static ssize_t store_drivers_autoprobe(struct bus_type *bus,  in store_drivers_autoprobe()  argument
238 		bus->p->drivers_autoprobe = 0;  in store_drivers_autoprobe()
240 		bus->p->drivers_autoprobe = 1;  in store_drivers_autoprobe()
244 static ssize_t store_drivers_probe(struct bus_type *bus,  in store_drivers_probe()  argument
249 	dev = bus_find_device_by_name(bus, NULL, buf);  in store_drivers_probe()
273  * @bus: bus type.
278  * Iterate over @bus's list of devices, and call @fn for each,
290 int bus_for_each_dev(struct bus_type *bus, struct device *start,  in bus_for_each_dev()  argument
297 	if (!bus)  in bus_for_each_dev()
300 	klist_iter_init_node(&bus->p->klist_devices, &i,  in bus_for_each_dev()
311  * @bus: bus type
324 struct device *bus_find_device(struct bus_type *bus,  in bus_find_device()  argument
331 	if (!bus)  in bus_find_device()
334 	klist_iter_init_node(&bus->p->klist_devices, &i,  in bus_find_device()
353  * @bus: bus type
361 struct device *bus_find_device_by_name(struct bus_type *bus,  in bus_find_device_by_name()  argument
364 	return bus_find_device(bus, start, (void *)name, match_name);  in bus_find_device_by_name()
423  * @bus: bus we're dealing with.
429  * We iterate over each driver that belongs to @bus, and call
440 int bus_for_each_drv(struct bus_type *bus, struct device_driver *start,  in bus_for_each_drv()  argument
447 	if (!bus)  in bus_for_each_drv()
450 	klist_iter_init_node(&bus->p->klist_drivers, &i,  in bus_for_each_drv()
459 static int device_add_attrs(struct bus_type *bus, struct device *dev)  in device_add_attrs()  argument
464 	if (!bus->dev_attrs)  in device_add_attrs()
467 	for (i = 0; attr_name(bus->dev_attrs[i]); i++) {  in device_add_attrs()
468 		error = device_create_file(dev, &bus->dev_attrs[i]);  in device_add_attrs()
471 				device_remove_file(dev, &bus->dev_attrs[i]);  in device_add_attrs()
478 static void device_remove_attrs(struct bus_type *bus, struct device *dev)  in device_remove_attrs()  argument
482 	if (bus->dev_attrs) {  in device_remove_attrs()
483 		for (i = 0; attr_name(bus->dev_attrs[i]); i++)  in device_remove_attrs()
484 			device_remove_file(dev, &bus->dev_attrs[i]);  in device_remove_attrs()
489  * bus_add_device - add device to bus
492  * - Add device's bus attributes.
493  * - Create links to device's bus.
494  * - Add the device to its bus's list of devices.
498 	struct bus_type *bus = bus_get(dev->bus);  in bus_add_device()  local
501 	if (bus) {  in bus_add_device()
502 		pr_debug("bus: '%s': add device %s\n", bus->name, dev_name(dev));  in bus_add_device()
503 		error = device_add_attrs(bus, dev);  in bus_add_device()
506 		error = sysfs_create_link(&bus->p->devices_kset->kobj,  in bus_add_device()
511 				&dev->bus->p->subsys.kobj, "subsystem");  in bus_add_device()
514 		klist_add_tail(&dev->p->knode_bus, &bus->p->klist_devices);  in bus_add_device()
519 	sysfs_remove_link(&bus->p->devices_kset->kobj, dev_name(dev));  in bus_add_device()
521 	device_remove_attrs(bus, dev);  in bus_add_device()
523 	bus_put(dev->bus);  in bus_add_device()
531  * - Automatically probe for a driver if the bus allows it.
535 	struct bus_type *bus = dev->bus;  in bus_probe_device()  local
539 	if (!bus)  in bus_probe_device()
542 	if (bus->p->drivers_autoprobe) {  in bus_probe_device()
547 	mutex_lock(&bus->p->mutex);  in bus_probe_device()
548 	list_for_each_entry(sif, &bus->p->interfaces, node)  in bus_probe_device()
551 	mutex_unlock(&bus->p->mutex);  in bus_probe_device()
555  * bus_remove_device - remove device from bus
559  * - Remove symlink from bus' directory.
560  * - Delete device from bus's list.
566 	struct bus_type *bus = dev->bus;  in bus_remove_device()  local
569 	if (!bus)  in bus_remove_device()
572 	mutex_lock(&bus->p->mutex);  in bus_remove_device()
573 	list_for_each_entry(sif, &bus->p->interfaces, node)  in bus_remove_device()
576 	mutex_unlock(&bus->p->mutex);  in bus_remove_device()
579 	sysfs_remove_link(&dev->bus->p->devices_kset->kobj,  in bus_remove_device()
581 	device_remove_attrs(dev->bus, dev);  in bus_remove_device()
585 	pr_debug("bus: '%s': remove device %s\n",  in bus_remove_device()
586 		 dev->bus->name, dev_name(dev));  in bus_remove_device()
588 	bus_put(dev->bus);  in bus_remove_device()
591 static int driver_add_attrs(struct bus_type *bus, struct device_driver *drv)  in driver_add_attrs()  argument
596 	if (bus->drv_attrs) {  in driver_add_attrs()
597 		for (i = 0; attr_name(bus->drv_attrs[i]); i++) {  in driver_add_attrs()
598 			error = driver_create_file(drv, &bus->drv_attrs[i]);  in driver_add_attrs()
607 		driver_remove_file(drv, &bus->drv_attrs[i]);  in driver_add_attrs()
611 static void driver_remove_attrs(struct bus_type *bus,  in driver_remove_attrs()  argument
616 	if (bus->drv_attrs) {  in driver_remove_attrs()
617 		for (i = 0; attr_name(bus->drv_attrs[i]); i++)  in driver_remove_attrs()
618 			driver_remove_file(drv, &bus->drv_attrs[i]);  in driver_remove_attrs()
650 static int add_probe_files(struct bus_type *bus)  in add_probe_files()  argument
654 	retval = bus_create_file(bus, &bus_attr_drivers_probe);  in add_probe_files()
658 	retval = bus_create_file(bus, &bus_attr_drivers_autoprobe);  in add_probe_files()
660 		bus_remove_file(bus, &bus_attr_drivers_probe);  in add_probe_files()
665 static void remove_probe_files(struct bus_type *bus)  in remove_probe_files()  argument
667 	bus_remove_file(bus, &bus_attr_drivers_autoprobe);  in remove_probe_files()
668 	bus_remove_file(bus, &bus_attr_drivers_probe);  in remove_probe_files()
673 static inline int add_probe_files(struct bus_type *bus) { return 0; }  in add_probe_files()  argument
674 static inline void remove_probe_files(struct bus_type *bus) {}  in remove_probe_files()  argument
689  * bus_add_driver - Add a driver to the bus.
694 	struct bus_type *bus;  in bus_add_driver()  local
698 	bus = bus_get(drv->bus);  in bus_add_driver()
699 	if (!bus)  in bus_add_driver()
702 	pr_debug("bus: '%s': add driver %s\n", bus->name, drv->name);  in bus_add_driver()
712 	priv->kobj.kset = bus->p->drivers_kset;  in bus_add_driver()
718 	if (drv->bus->p->drivers_autoprobe) {  in bus_add_driver()
723 	klist_add_tail(&priv->knode_bus, &bus->p->klist_drivers);  in bus_add_driver()
731 	error = driver_add_attrs(bus, drv);  in bus_add_driver()
755 	bus_put(bus);  in bus_add_driver()
760  * bus_remove_driver - delete driver from bus's knowledge.
764  * it from its bus's list of drivers. Finally, we drop the reference
765  * to the bus we took in bus_add_driver().
769 	if (!drv->bus)  in bus_remove_driver()
774 	driver_remove_attrs(drv->bus, drv);  in bus_remove_driver()
777 	pr_debug("bus: '%s': remove driver %s\n", drv->bus->name, drv->name);  in bus_remove_driver()
781 	bus_put(drv->bus);  in bus_remove_driver()
801  * bus_rescan_devices - rescan devices on the bus for possible drivers
802  * @bus: the bus to scan.
804  * This function will look for devices on the bus with no driver
808 int bus_rescan_devices(struct bus_type *bus)  in bus_rescan_devices()  argument
810 	return bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);  in bus_rescan_devices()
837  * find_bus - locate bus by name.
838  * @name: name of bus.
841  * find a bus by name. Return bus if found.
843  * Note that kset_find_obj increments bus' reference count.
855  * bus_add_attrs - Add default attributes for this bus.
856  * @bus: Bus that has just been registered.
859 static int bus_add_attrs(struct bus_type *bus)  in bus_add_attrs()  argument
864 	if (bus->bus_attrs) {  in bus_add_attrs()
865 		for (i = 0; attr_name(bus->bus_attrs[i]); i++) {  in bus_add_attrs()
866 			error = bus_create_file(bus, &bus->bus_attrs[i]);  in bus_add_attrs()
875 		bus_remove_file(bus, &bus->bus_attrs[i]);  in bus_add_attrs()
879 static void bus_remove_attrs(struct bus_type *bus)  in bus_remove_attrs()  argument
883 	if (bus->bus_attrs) {  in bus_remove_attrs()
884 		for (i = 0; attr_name(bus->bus_attrs[i]); i++)  in bus_remove_attrs()
885 			bus_remove_file(bus, &bus->bus_attrs[i]);  in bus_remove_attrs()
905 static ssize_t bus_uevent_store(struct bus_type *bus,  in bus_uevent_store()  argument
911 		kobject_uevent(&bus->p->subsys.kobj, action);  in bus_uevent_store()
918  * @bus: bus to register
921  * Once we have that, we register the bus with the kobject
925 int __bus_register(struct bus_type *bus, struct lock_class_key *key)  in __bus_register()  argument
934 	priv->bus = bus;  in __bus_register()
935 	bus->p = priv;  in __bus_register()
939 	retval = kobject_set_name(&priv->subsys.kobj, "%s", bus->name);  in __bus_register()
951 	retval = bus_create_file(bus, &bus_attr_uevent);  in __bus_register()
974 	retval = add_probe_files(bus);  in __bus_register()
978 	retval = bus_add_attrs(bus);  in __bus_register()
982 	pr_debug("bus: '%s': registered\n", bus->name);  in __bus_register()
986 	remove_probe_files(bus);  in __bus_register()
988 	kset_unregister(bus->p->drivers_kset);  in __bus_register()
990 	kset_unregister(bus->p->devices_kset);  in __bus_register()
992 	bus_remove_file(bus, &bus_attr_uevent);  in __bus_register()
994 	kset_unregister(&bus->p->subsys);  in __bus_register()
996 	kfree(bus->p);  in __bus_register()
997 	bus->p = NULL;  in __bus_register()
1003  * bus_unregister - remove a bus from the system
1004  * @bus: bus.
1006  * Unregister the child subsystems and the bus itself.
1009 void bus_unregister(struct bus_type *bus)  in bus_unregister()  argument
1011 	pr_debug("bus: '%s': unregistering\n", bus->name);  in bus_unregister()
1012 	if (bus->dev_root)  in bus_unregister()
1013 		device_unregister(bus->dev_root);  in bus_unregister()
1014 	bus_remove_attrs(bus);  in bus_unregister()
1015 	remove_probe_files(bus);  in bus_unregister()
1016 	kset_unregister(bus->p->drivers_kset);  in bus_unregister()
1017 	kset_unregister(bus->p->devices_kset);  in bus_unregister()
1018 	bus_remove_file(bus, &bus_attr_uevent);  in bus_unregister()
1019 	kset_unregister(&bus->p->subsys);  in bus_unregister()
1020 	kfree(bus->p);  in bus_unregister()
1021 	bus->p = NULL;  in bus_unregister()
1025 int bus_register_notifier(struct bus_type *bus, struct notifier_block *nb)  in bus_register_notifier()  argument
1027 	return blocking_notifier_chain_register(&bus->p->bus_notifier, nb);  in bus_register_notifier()
1031 int bus_unregister_notifier(struct bus_type *bus, struct notifier_block *nb)  in bus_unregister_notifier()  argument
1033 	return blocking_notifier_chain_unregister(&bus->p->bus_notifier, nb);  in bus_unregister_notifier()
1037 struct kset *bus_get_kset(struct bus_type *bus)  in bus_get_kset()  argument
1039 	return &bus->p->subsys;  in bus_get_kset()
1043 struct klist *bus_get_device_klist(struct bus_type *bus)  in bus_get_device_klist()  argument
1045 	return &bus->p->klist_devices;  in bus_get_device_klist()
1078 void bus_sort_breadthfirst(struct bus_type *bus,  in bus_sort_breadthfirst()  argument
1089 	device_klist = bus_get_device_klist(bus);  in bus_sort_breadthfirst()
1284 	bus_kset = kset_create_and_add("bus", &bus_uevent_ops, NULL);  in buses_init()