diff options
Diffstat (limited to 'drivers/base/bus.c')
-rw-r--r-- | drivers/base/bus.c | 300 |
1 files changed, 52 insertions, 248 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 2b3902c867d..43722af90bd 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -17,9 +17,6 @@ #include "base.h" #include "power/power.h" -#define to_dev(node) container_of(node, struct device, bus_list) -#define to_drv(node) container_of(node, struct device_driver, kobj.entry) - #define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr) #define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj) @@ -36,7 +33,7 @@ drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) { struct driver_attribute * drv_attr = to_drv_attr(attr); struct device_driver * drv = to_driver(kobj); - ssize_t ret = 0; + ssize_t ret = -EIO; if (drv_attr->show) ret = drv_attr->show(drv, buf); @@ -49,7 +46,7 @@ drv_attr_store(struct kobject * kobj, struct attribute * attr, { struct driver_attribute * drv_attr = to_drv_attr(attr); struct device_driver * drv = to_driver(kobj); - ssize_t ret = 0; + ssize_t ret = -EIO; if (drv_attr->store) ret = drv_attr->store(drv, buf, count); @@ -135,50 +132,11 @@ static struct kobj_type ktype_bus = { 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 *)) +static struct device * next_device(struct klist_iter * i) { - 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; + struct klist_node * n = klist_next(i); + return n ? container_of(n, struct device, knode_bus) : NULL; } /** @@ -204,12 +162,27 @@ static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start, 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; +} + + + +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; } /** @@ -235,180 +208,19 @@ 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; - - down_read(&bus->subsys.rwsem); - ret = __bus_for_each_drv(bus, start, data, fn); - up_read(&bus->subsys.rwsem); - return ret; -} - -/** - * device_bind_driver - bind a driver to one device. - * @dev: device. - * - * Allow manual attachment of a driver to a device. - * Caller must have already set @dev->driver. - * - * Note that this does not modify the bus reference count - * nor take the bus's rwsem. Please verify those are accounted - * for before calling this. (It is ok to call with no other effort - * from a driver's probe() method.) - */ - -void device_bind_driver(struct device * dev) -{ - pr_debug("bound device '%s' to driver '%s'\n", - dev->bus_id, dev->driver->name); - list_add_tail(&dev->driver_list, &dev->driver->devices); - sysfs_create_link(&dev->driver->kobj, &dev->kobj, - kobject_name(&dev->kobj)); - sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver"); -} - - -/** - * driver_probe_device - attempt to bind device & driver. - * @drv: driver. - * @dev: device. - * - * First, we call the bus's match function, if one present, which - * should compare the device IDs the driver supports with the - * device IDs of the device. Note we don't do this ourselves - * because we don't know the format of the ID structures, nor what - * is to be considered a match and what is not. - * - * If we find a match, we call @drv->probe(@dev) if it exists, and - * call device_bind_driver() above. - */ -int driver_probe_device(struct device_driver * drv, struct device * dev) -{ - if (drv->bus->match && !drv->bus->match(dev, drv)) - return -ENODEV; - - dev->driver = drv; - if (drv->probe) { - int error = drv->probe(dev); - if (error) { - dev->driver = NULL; - return error; - } - } - - device_bind_driver(dev); - return 0; -} - - -/** - * device_attach - try to attach device to a driver. - * @dev: device. - * - * Walk the list of drivers that the bus has and call - * driver_probe_device() for each pair. If a compatible - * pair is found, break out and return. - */ -int device_attach(struct device * dev) -{ - struct bus_type * bus = dev->bus; - struct list_head * entry; - int error; - - if (dev->driver) { - device_bind_driver(dev); - return 1; - } - - if (bus->match) { - list_for_each(entry, &bus->drivers.list) { - struct device_driver * drv = to_drv(entry); - error = driver_probe_device(drv, dev); - if (!error) - /* success, driver matched */ - return 1; - if (error != -ENODEV && error != -ENXIO) - /* driver matched but the probe failed */ - printk(KERN_WARNING - "%s: probe of %s failed with error %d\n", - drv->name, dev->bus_id, error); - } - } - - return 0; -} - - -/** - * driver_attach - try to bind driver to devices. - * @drv: driver. - * - * Walk the list of devices that the bus has on it and try to - * match the driver with each one. If driver_probe_device() - * returns 0 and the @dev->driver is set, we've found a - * compatible pair. - * - * Note that we ignore the -ENODEV error from driver_probe_device(), - * since it's perfectly valid for a driver not to bind to any devices. - */ -void driver_attach(struct device_driver * drv) -{ - struct bus_type * bus = drv->bus; - struct list_head * entry; - int error; - - if (!bus->match) - return; - - list_for_each(entry, &bus->devices.list) { - struct device * dev = container_of(entry, struct device, bus_list); - if (!dev->driver) { - error = driver_probe_device(drv, dev); - if (error && (error != -ENODEV)) - /* driver matched but the probe failed */ - printk(KERN_WARNING - "%s: probe of %s failed with error %d\n", - drv->name, dev->bus_id, error); - } - } -} - - -/** - * device_release_driver - manually detach device from driver. - * @dev: device. - * - * Manually detach device from driver. - * Note that this is called without incrementing the bus - * reference count nor taking the bus's rwsem. Be sure that - * those are accounted for before calling this function. - */ - -void device_release_driver(struct device * dev) -{ - struct device_driver * drv = dev->driver; - if (drv) { - sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj)); - sysfs_remove_link(&dev->kobj, "driver"); - list_del_init(&dev->driver_list); - device_detach_shutdown(dev); - if (drv->remove) - drv->remove(dev); - dev->driver = NULL; - } -} - + struct klist_iter i; + struct device_driver * drv; + int error = 0; -/** - * driver_detach - detach driver from all devices it controls. - * @drv: driver. - */ + if (!bus) + return -EINVAL; -static void driver_detach(struct device_driver * drv) -{ - while (!list_empty(&drv->devices)) { - struct device * dev = container_of(drv->devices.next, struct device, driver_list); - device_release_driver(dev); - } + 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) @@ -457,14 +269,15 @@ int bus_add_device(struct device * dev) int error = 0; if (bus) { - down_write(&dev->bus->subsys.rwsem); pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id); - list_add_tail(&dev->bus_list, &dev->bus->devices.list); - device_attach(dev); - up_write(&dev->bus->subsys.rwsem); - 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"); + error = device_attach(dev); + klist_add_tail(&bus->klist_devices, &dev->knode_bus); + if (error >= 0) + error = device_add_attrs(bus, dev); + if (!error) { + sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id); + sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus"); + } } return error; } @@ -484,11 +297,9 @@ void bus_remove_device(struct device * dev) sysfs_remove_link(&dev->kobj, "bus"); sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id); device_remove_attrs(dev->bus, dev); - down_write(&dev->bus->subsys.rwsem); + klist_remove(&dev->knode_bus); pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id); device_release_driver(dev); - list_del_init(&dev->bus_list); - up_write(&dev->bus->subsys.rwsem); put_bus(dev->bus); } } @@ -548,9 +359,8 @@ int bus_add_driver(struct device_driver * drv) return error; } - 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); @@ -572,10 +382,9 @@ void bus_remove_driver(struct device_driver * drv) { if (drv->bus) { driver_remove_attrs(drv->bus, drv); - down_write(&drv->bus->subsys.rwsem); + klist_remove(&drv->knode_bus); pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name); driver_detach(drv); - up_write(&drv->bus->subsys.rwsem); module_remove_driver(drv); kobject_unregister(&drv->kobj); put_bus(drv->bus); @@ -588,7 +397,7 @@ static int bus_rescan_devices_helper(struct device *dev, void *data) { int *count = data; - if (!dev->driver && device_attach(dev)) + if (!dev->driver && (device_attach(dev) > 0)) (*count)++; return 0; @@ -608,9 +417,7 @@ int bus_rescan_devices(struct bus_type * bus) { 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; } @@ -711,6 +518,9 @@ int bus_register(struct bus_type * bus) retval = kset_register(&bus->drivers); if (retval) 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); @@ -750,12 +560,6 @@ int __init buses_init(void) EXPORT_SYMBOL_GPL(bus_for_each_dev); EXPORT_SYMBOL_GPL(bus_for_each_drv); -EXPORT_SYMBOL_GPL(driver_probe_device); -EXPORT_SYMBOL_GPL(device_bind_driver); -EXPORT_SYMBOL_GPL(device_release_driver); -EXPORT_SYMBOL_GPL(device_attach); -EXPORT_SYMBOL_GPL(driver_attach); - EXPORT_SYMBOL_GPL(bus_add_device); EXPORT_SYMBOL_GPL(bus_remove_device); EXPORT_SYMBOL_GPL(bus_register); |