From foo@baz Tue Apr 9 12:12:43 2002 To: Greg KH Date: 21 Mar 2005 11:49:14 -08:00 From: mochel@digitalimplant.org Subject: [driver core] Add a klist to struct bus_type for its devices. - Use it for bus_for_each_dev(). - Use the klist spinlock instead of the bus rwsem. Signed-off-by: Patrick Mochel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 54 +++++++++++++++++++++---------------------------- include/linux/device.h | 3 ++ 2 files changed, 27 insertions(+), 30 deletions(-) --- gregkh-2.6.orig/drivers/base/bus.c 2005-05-05 11:07:28.000000000 -0700 +++ gregkh-2.6/drivers/base/bus.c 2005-05-05 11:07:34.000000000 -0700 @@ -134,28 +134,6 @@ decl_subsys(bus, &ktype_bus, NULL); -static int __bus_for_each_dev(struct bus_type *bus, struct device *start, - void *data, int (*fn)(struct device *, void *)) -{ - struct list_head *head; - struct device *dev; - int error = 0; - - if (!(bus = get_bus(bus))) - return -EINVAL; - - head = &bus->devices.list; - dev = list_prepare_entry(start, head, bus_list); - list_for_each_entry_continue(dev, head, bus_list) { - get_device(dev); - error = fn(dev, data); - put_device(dev); - if (error) - break; - } - put_bus(bus); - return error; -} static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, void * data, int (*fn)(struct device_driver *, void *)) @@ -180,6 +158,13 @@ return error; } + +static struct device * next_device(struct klist_iter * i) +{ + struct klist_node * n = klist_next(i); + return n ? container_of(n, struct device, knode_bus) : NULL; +} + /** * bus_for_each_dev - device iterator. * @bus: bus type. @@ -203,12 +188,19 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, void * data, int (*fn)(struct device *, void *)) { - int ret; + struct klist_iter i; + struct device * dev; + int error = 0; - down_read(&bus->subsys.rwsem); - ret = __bus_for_each_dev(bus, start, data, fn); - up_read(&bus->subsys.rwsem); - return ret; + if (!bus) + return -EINVAL; + + klist_iter_init_node(&bus->klist_devices, &i, + (start ? &start->knode_bus : NULL)); + while ((dev = next_device(&i)) && !error) + error = fn(dev, data); + klist_iter_exit(&i); + return error; } /** @@ -293,6 +285,7 @@ list_add_tail(&dev->bus_list, &dev->bus->devices.list); device_attach(dev); up_write(&dev->bus->subsys.rwsem); + klist_add_tail(&bus->klist_devices, &dev->knode_bus); device_add_attrs(bus, dev); sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); @@ -315,6 +308,7 @@ sysfs_remove_link(&dev->kobj, "bus"); sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); device_remove_attrs(dev->bus, dev); + klist_remove(&dev->knode_bus); down_write(&dev->bus->subsys.rwsem); pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); device_release_driver(dev); @@ -439,9 +433,7 @@ { int count = 0; - down_write(&bus->subsys.rwsem); - __bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper); - up_write(&bus->subsys.rwsem); + bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper); return count; } @@ -542,6 +534,8 @@ retval = kset_register(&bus->drivers); if (retval) goto bus_drivers_fail; + + klist_init(&bus->klist_devices); bus_add_attrs(bus); pr_debug("bus type '%s' registered\n", bus->name); --- gregkh-2.6.orig/include/linux/device.h 2005-05-05 11:07:29.000000000 -0700 +++ gregkh-2.6/include/linux/device.h 2005-05-05 11:07:34.000000000 -0700 @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -51,6 +52,7 @@ struct subsystem subsys; struct kset drivers; struct kset devices; + struct klist klist_devices; struct bus_attribute * bus_attrs; struct device_attribute * dev_attrs; @@ -262,6 +264,7 @@ struct list_head bus_list; /* node in bus's list */ struct list_head driver_list; struct list_head children; + struct klist_node knode_bus; struct device * parent; struct kobject kobj;