Commit 38fdac3c authored by Patrick Mochel's avatar Patrick Mochel Committed by Greg Kroah-Hartman
Browse files

[PATCH] Add a klist to struct bus_type for its drivers. 



- Use it in bus_for_each_drv().
- Use the klist spinlock instead of the bus rwsem.

Signed-off-by: default avatarPatrick Mochel <mochel@digitalimplant.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 465c7a3a

drivers/base/bus.c

+23 −29
Original line number Diff line number Diff line
@@ -135,30 +135,6 @@ static struct kobj_type ktype_bus = { 
decl_subsys(bus, &ktype_bus, NULL);





static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start,

			      void * data, int (*fn)(struct device_driver *, void *))

{

	struct list_head *head;

	struct device_driver *drv;

	int error = 0;



	if (!(bus = get_bus(bus)))

		return -EINVAL;



	head = &bus->drivers.list;

	drv = list_prepare_entry(start, head, kobj.entry);

	list_for_each_entry_continue(drv, head, kobj.entry) {

		get_driver(drv);

		error = fn(drv, data);

		put_driver(drv);

		if (error)

			break;

	}

	put_bus(bus);

	return error;

}





static struct device * next_device(struct klist_iter * i)

{

	struct klist_node * n = klist_next(i);
@@ -203,6 +179,14 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, 
	return error;

}







static struct device_driver * next_driver(struct klist_iter * i)

{

	struct klist_node * n = klist_next(i);

	return n ? container_of(n, struct device_driver, knode_bus) : NULL;

}



/**

 *	bus_for_each_drv - driver iterator

 *	@bus:	bus we're dealing with.
@@ -226,12 +210,19 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, 
int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,

		     void * data, int (*fn)(struct device_driver *, void *))

{

	int ret;

	struct klist_iter i;

	struct device_driver * drv;

	int error = 0;



	down_read(&bus->subsys.rwsem);

	ret = __bus_for_each_drv(bus, start, data, fn);

	up_read(&bus->subsys.rwsem);

	return ret;

	if (!bus)

		return -EINVAL;



	klist_iter_init_node(&bus->klist_drivers, &i,

			     start ? &start->knode_bus : NULL);

	while ((drv = next_driver(&i)) && !error)

		error = fn(drv, data);

	klist_iter_exit(&i);

	return error;

}



static int device_add_attrs(struct bus_type * bus, struct device * dev)
@@ -376,6 +367,7 @@ int bus_add_driver(struct device_driver * drv) 
		down_write(&bus->subsys.rwsem);

		driver_attach(drv);

		up_write(&bus->subsys.rwsem);

		klist_add_tail(&bus->klist_drivers, &drv->knode_bus);

		module_add_driver(drv->owner, drv);



		driver_add_attrs(bus, drv);
@@ -397,6 +389,7 @@ void bus_remove_driver(struct device_driver * drv) 
{

	if (drv->bus) {

		driver_remove_attrs(drv->bus, drv);

		klist_remove(&drv->knode_bus);

		down_write(&drv->bus->subsys.rwsem);

		pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);

		driver_detach(drv);
@@ -536,6 +529,7 @@ int bus_register(struct bus_type * bus) 
		goto bus_drivers_fail;



	klist_init(&bus->klist_devices);

	klist_init(&bus->klist_drivers);

	bus_add_attrs(bus);



	pr_debug("bus type '%s' registered\n", bus->name);

include/linux/device.h

+2 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ struct bus_type { 
	struct kset		drivers;

	struct kset		devices;

	struct klist		klist_devices;

	struct klist		klist_drivers;



	struct bus_attribute	* bus_attrs;

	struct device_attribute	* dev_attrs;
@@ -105,6 +106,7 @@ struct device_driver { 
	struct completion	unloaded;

	struct kobject		kobj;

	struct list_head	devices;

	struct klist_node	knode_bus;



	struct module		* owner;