}
}
+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;
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);
}
#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
* 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;
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;
}
*
* 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;
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)
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);
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)
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);
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff