diff options
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/base.h | 2 | ||||
| -rw-r--r-- | drivers/base/class.c | 136 | ||||
| -rw-r--r-- | drivers/base/core.c | 6 |
3 files changed, 107 insertions, 37 deletions
diff --git a/drivers/base/base.h b/drivers/base/base.h index 31dc0cd84af..0a5f055dffb 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -54,7 +54,7 @@ struct driver_private { */ struct class_private { struct kset class_subsys; - struct list_head class_devices; + struct klist class_devices; struct list_head class_interfaces; struct kset class_dirs; struct mutex class_mutex; diff --git a/drivers/base/class.c b/drivers/base/class.c index cc5e28c8885..eb85e431230 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -135,6 +135,20 @@ static void remove_class_attrs(struct class *cls) } } +static void klist_class_dev_get(struct klist_node *n) +{ + struct device *dev = container_of(n, struct device, knode_class); + + get_device(dev); +} + +static void klist_class_dev_put(struct klist_node *n) +{ + struct device *dev = container_of(n, struct device, knode_class); + + put_device(dev); +} + int __class_register(struct class *cls, struct lock_class_key *key) { struct class_private *cp; @@ -145,7 +159,7 @@ int __class_register(struct class *cls, struct lock_class_key *key) cp = kzalloc(sizeof(*cp), GFP_KERNEL); if (!cp) return -ENOMEM; - INIT_LIST_HEAD(&cp->class_devices); + klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put); INIT_LIST_HEAD(&cp->class_interfaces); kset_init(&cp->class_dirs); __mutex_init(&cp->class_mutex, "struct class mutex", key); @@ -269,6 +283,71 @@ char *make_class_name(const char *name, struct kobject *kobj) #endif /** + * class_dev_iter_init - initialize class device iterator + * @iter: class iterator to initialize + * @class: the class we wanna iterate over + * @start: the device to start iterating from, if any + * @type: device_type of the devices to iterate over, NULL for all + * + * Initialize class iterator @iter such that it iterates over devices + * of @class. If @start is set, the list iteration will start there, + * otherwise if it is NULL, the iteration starts at the beginning of + * the list. + */ +void class_dev_iter_init(struct class_dev_iter *iter, struct class *class, + struct device *start, const struct device_type *type) +{ + struct klist_node *start_knode = NULL; + + if (start) + start_knode = &start->knode_class; + klist_iter_init_node(&class->p->class_devices, &iter->ki, start_knode); + iter->type = type; +} +EXPORT_SYMBOL_GPL(class_dev_iter_init); + +/** + * class_dev_iter_next - iterate to the next device + * @iter: class iterator to proceed + * + * Proceed @iter to the next device and return it. Returns NULL if + * iteration is complete. + * + * The returned device is referenced and won't be released till + * iterator is proceed to the next device or exited. The caller is + * free to do whatever it wants to do with the device including + * calling back into class code. + */ +struct device *class_dev_iter_next(struct class_dev_iter *iter) +{ + struct klist_node *knode; + struct device *dev; + + while (1) { + knode = klist_next(&iter->ki); + if (!knode) + return NULL; + dev = container_of(knode, struct device, knode_class); + if (!iter->type || iter->type == dev->type) + return dev; + } +} +EXPORT_SYMBOL_GPL(class_dev_iter_next); + +/** + * class_dev_iter_exit - finish iteration + * @iter: class iterator to finish + * + * Finish an iteration. Always call this function after iteration is + * complete whether the iteration ran till the end or not. + */ +void class_dev_iter_exit(struct class_dev_iter *iter) +{ + klist_iter_exit(&iter->ki); +} +EXPORT_SYMBOL_GPL(class_dev_iter_exit); + +/** * class_for_each_device - device iterator * @class: the class we're iterating * @start: the device to start with in the list, if any. @@ -283,13 +362,13 @@ char *make_class_name(const char *name, struct kobject *kobj) * We check the return of @fn each time. If it returns anything * other than 0, we break out and return that value. * - * Note, we hold class->class_mutex in this function, so it can not be - * re-acquired in @fn, otherwise it will self-deadlocking. For - * example, calls to add or remove class members would be verboten. + * @fn is allowed to do anything including calling back into class + * code. There's no locking restriction. */ int class_for_each_device(struct class *class, struct device *start, void *data, int (*fn)(struct device *, void *)) { + struct class_dev_iter iter; struct device *dev; int error = 0; @@ -301,20 +380,13 @@ int class_for_each_device(struct class *class, struct device *start, return -EINVAL; } - mutex_lock(&class->p->class_mutex); - list_for_each_entry(dev, &class->p->class_devices, node) { - if (start) { - if (start == dev) - start = NULL; - continue; - } - dev = get_device(dev); + class_dev_iter_init(&iter, class, start, NULL); + while ((dev = class_dev_iter_next(&iter))) { error = fn(dev, data); - put_device(dev); if (error) break; } - mutex_unlock(&class->p->class_mutex); + class_dev_iter_exit(&iter); return error; } @@ -337,16 +409,15 @@ EXPORT_SYMBOL_GPL(class_for_each_device); * * Note, you will need to drop the reference with put_device() after use. * - * We hold class->class_mutex in this function, so it can not be - * re-acquired in @match, otherwise it will self-deadlocking. For - * example, calls to add or remove class members would be verboten. + * @fn is allowed to do anything including calling back into class + * code. There's no locking restriction. */ struct device *class_find_device(struct class *class, struct device *start, void *data, int (*match)(struct device *, void *)) { + struct class_dev_iter iter; struct device *dev; - int found = 0; if (!class) return NULL; @@ -356,29 +427,23 @@ struct device *class_find_device(struct class *class, struct device *start, return NULL; } - mutex_lock(&class->p->class_mutex); - list_for_each_entry(dev, &class->p->class_devices, node) { - if (start) { - if (start == dev) - start = NULL; - continue; - } - dev = get_device(dev); + class_dev_iter_init(&iter, class, start, NULL); + while ((dev = class_dev_iter_next(&iter))) { if (match(dev, data)) { - found = 1; + get_device(dev); break; - } else - put_device(dev); + } } - mutex_unlock(&class->p->class_mutex); + class_dev_iter_exit(&iter); - return found ? dev : NULL; + return dev; } EXPORT_SYMBOL_GPL(class_find_device); int class_interface_register(struct class_interface *class_intf) { struct class *parent; + struct class_dev_iter iter; struct device *dev; if (!class_intf || !class_intf->class) @@ -391,8 +456,10 @@ int class_interface_register(struct class_interface *class_intf) mutex_lock(&parent->p->class_mutex); list_add_tail(&class_intf->node, &parent->p->class_interfaces); if (class_intf->add_dev) { - list_for_each_entry(dev, &parent->p->class_devices, node) + class_dev_iter_init(&iter, parent, NULL, NULL); + while ((dev = class_dev_iter_next(&iter))) class_intf->add_dev(dev, class_intf); + class_dev_iter_exit(&iter); } mutex_unlock(&parent->p->class_mutex); @@ -402,6 +469,7 @@ int class_interface_register(struct class_interface *class_intf) void class_interface_unregister(struct class_interface *class_intf) { struct class *parent = class_intf->class; + struct class_dev_iter iter; struct device *dev; if (!parent) @@ -410,8 +478,10 @@ void class_interface_unregister(struct class_interface *class_intf) mutex_lock(&parent->p->class_mutex); list_del_init(&class_intf->node); if (class_intf->remove_dev) { - list_for_each_entry(dev, &parent->p->class_devices, node) + class_dev_iter_init(&iter, parent, NULL, NULL); + while ((dev = class_dev_iter_next(&iter))) class_intf->remove_dev(dev, class_intf); + class_dev_iter_exit(&iter); } mutex_unlock(&parent->p->class_mutex); diff --git a/drivers/base/core.c b/drivers/base/core.c index d021c98605b..b98cb1416a2 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -536,7 +536,6 @@ void device_initialize(struct device *dev) klist_init(&dev->klist_children, klist_children_get, klist_children_put); INIT_LIST_HEAD(&dev->dma_pools); - INIT_LIST_HEAD(&dev->node); init_MUTEX(&dev->sem); spin_lock_init(&dev->devres_lock); INIT_LIST_HEAD(&dev->devres_head); @@ -916,7 +915,8 @@ int device_add(struct device *dev) if (dev->class) { mutex_lock(&dev->class->p->class_mutex); /* tie the class to the device */ - list_add_tail(&dev->node, &dev->class->p->class_devices); + klist_add_tail(&dev->knode_class, + &dev->class->p->class_devices); /* notify any interfaces that the device is here */ list_for_each_entry(class_intf, @@ -1032,7 +1032,7 @@ void device_del(struct device *dev) if (class_intf->remove_dev) class_intf->remove_dev(dev, class_intf); /* remove the device from the class list */ - list_del_init(&dev->node); + klist_del(&dev->knode_class); mutex_unlock(&dev->class->p->class_mutex); } device_remove_file(dev, &uevent_attr); |