#endif /* CONFIG_PROC_FS */
+struct netdev_upper {
+ struct net_device *dev;
+ bool master;
+ struct list_head list;
+ struct rcu_head rcu;
+ struct list_head search_list;
+};
+
+static void __append_search_uppers(struct list_head *search_list,
+ struct net_device *dev)
+{
+ struct netdev_upper *upper;
+
+ list_for_each_entry(upper, &dev->upper_dev_list, list) {
+ /* check if this upper is not already in search list */
+ if (list_empty(&upper->search_list))
+ list_add_tail(&upper->search_list, search_list);
+ }
+}
+
+static bool __netdev_search_upper_dev(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ LIST_HEAD(search_list);
+ struct netdev_upper *upper;
+ struct netdev_upper *tmp;
+ bool ret = false;
+
+ __append_search_uppers(&search_list, dev);
+ list_for_each_entry(upper, &search_list, search_list) {
+ if (upper->dev == upper_dev) {
+ ret = true;
+ break;
+ }
+ __append_search_uppers(&search_list, upper->dev);
+ }
+ list_for_each_entry_safe(upper, tmp, &search_list, search_list)
+ INIT_LIST_HEAD(&upper->search_list);
+ return ret;
+}
+
+static struct netdev_upper *__netdev_find_upper(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ struct netdev_upper *upper;
+
+ list_for_each_entry(upper, &dev->upper_dev_list, list) {
+ if (upper->dev == upper_dev)
+ return upper;
+ }
+ return NULL;
+}
+
+/**
+ * netdev_has_upper_dev - Check if device is linked to an upper device
+ * @dev: device
+ * @upper_dev: upper device to check
+ *
+ * Find out if a device is linked to specified upper device and return true
+ * in case it is. Note that this checks only immediate upper device,
+ * not through a complete stack of devices. The caller must hold the RTNL lock.
+ */
+bool netdev_has_upper_dev(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ ASSERT_RTNL();
+
+ return __netdev_find_upper(dev, upper_dev);
+}
+EXPORT_SYMBOL(netdev_has_upper_dev);
+
+/**
+ * netdev_has_any_upper_dev - Check if device is linked to some device
+ * @dev: device
+ *
+ * Find out if a device is linked to an upper device and return true in case
+ * it is. The caller must hold the RTNL lock.
+ */
+bool netdev_has_any_upper_dev(struct net_device *dev)
+{
+ ASSERT_RTNL();
+
+ return !list_empty(&dev->upper_dev_list);
+}
+EXPORT_SYMBOL(netdev_has_any_upper_dev);
+
+/**
+ * netdev_master_upper_dev_get - Get master upper device
+ * @dev: device
+ *
+ * Find a master upper device and return pointer to it or NULL in case
+ * it's not there. The caller must hold the RTNL lock.
+ */
+struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
+{
+ struct netdev_upper *upper;
+
+ ASSERT_RTNL();
+
+ if (list_empty(&dev->upper_dev_list))
+ return NULL;
+
+ upper = list_first_entry(&dev->upper_dev_list,
+ struct netdev_upper, list);
+ if (likely(upper->master))
+ return upper->dev;
+ return NULL;
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_get);
+
+/**
+ * netdev_master_upper_dev_get_rcu - Get master upper device
+ * @dev: device
+ *
+ * Find a master upper device and return pointer to it or NULL in case
+ * it's not there. The caller must hold the RCU read lock.
+ */
+struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
+{
+ struct netdev_upper *upper;
+
+ upper = list_first_or_null_rcu(&dev->upper_dev_list,
+ struct netdev_upper, list);
+ if (upper && likely(upper->master))
+ return upper->dev;
+ return NULL;
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
+
+static int __netdev_upper_dev_link(struct net_device *dev,
+ struct net_device *upper_dev, bool master)
+{
+ struct netdev_upper *upper;
+
+ ASSERT_RTNL();
+
+ if (dev == upper_dev)
+ return -EBUSY;
+
+ /* To prevent loops, check if dev is not upper device to upper_dev. */
+ if (__netdev_search_upper_dev(upper_dev, dev))
+ return -EBUSY;
+
+ if (__netdev_find_upper(dev, upper_dev))
+ return -EEXIST;
+
+ if (master && netdev_master_upper_dev_get(dev))
+ return -EBUSY;
+
+ upper = kmalloc(sizeof(*upper), GFP_KERNEL);
+ if (!upper)
+ return -ENOMEM;
+
+ upper->dev = upper_dev;
+ upper->master = master;
+ INIT_LIST_HEAD(&upper->search_list);
+
+ /* Ensure that master upper link is always the first item in list. */
+ if (master)
+ list_add_rcu(&upper->list, &dev->upper_dev_list);
+ else
+ list_add_tail_rcu(&upper->list, &dev->upper_dev_list);
+ dev_hold(upper_dev);
+
+ return 0;
+}
+
+/**
+ * netdev_upper_dev_link - Add a link to the upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ *
+ * Adds a link to device which is upper to this one. The caller must hold
+ * the RTNL lock. On a failure a negative errno code is returned.
+ * On success the reference counts are adjusted and the function
+ * returns zero.
+ */
+int netdev_upper_dev_link(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ return __netdev_upper_dev_link(dev, upper_dev, false);
+}
+EXPORT_SYMBOL(netdev_upper_dev_link);
+
+/**
+ * netdev_master_upper_dev_link - Add a master link to the upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ *
+ * Adds a link to device which is upper to this one. In this case, only
+ * one master upper device can be linked, although other non-master devices
+ * might be linked as well. The caller must hold the RTNL lock.
+ * On a failure a negative errno code is returned. On success the reference
+ * counts are adjusted and the function returns zero.
+ */
+int netdev_master_upper_dev_link(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ return __netdev_upper_dev_link(dev, upper_dev, true);
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_link);
+
+/**
+ * netdev_upper_dev_unlink - Removes a link to upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ *
+ * Removes a link to device which is upper to this one. The caller must hold
+ * the RTNL lock.
+ */
+void netdev_upper_dev_unlink(struct net_device *dev,
+ struct net_device *upper_dev)
+{
+ struct netdev_upper *upper;
+
+ ASSERT_RTNL();
+
+ upper = __netdev_find_upper(dev, upper_dev);
+ if (!upper)
+ return;
+ list_del_rcu(&upper->list);
+ dev_put(upper_dev);
+ kfree_rcu(upper, rcu);
+}
+EXPORT_SYMBOL(netdev_upper_dev_unlink);
+
/**
* netdev_set_master - set up master pointer
* @slave: slave device
int netdev_set_master(struct net_device *slave, struct net_device *master)
{
struct net_device *old = slave->master;
+ int err;
ASSERT_RTNL();
if (master) {
if (old)
return -EBUSY;
- dev_hold(master);
+ err = netdev_master_upper_dev_link(slave, master);
+ if (err)
+ return err;
}
slave->master = master;
if (old)
- dev_put(old);
+ netdev_upper_dev_unlink(slave, master);
+
return 0;
}
EXPORT_SYMBOL(netdev_set_master);
if (dev->netdev_ops->ndo_uninit)
dev->netdev_ops->ndo_uninit(dev);
- /* Notifier chain MUST detach us from master device. */
- WARN_ON(dev->master);
+ /* Notifier chain MUST detach us all upper devices. */
+ WARN_ON(netdev_has_any_upper_dev(dev));
/* Remove entries from kobject tree */
netdev_unregister_kobject(dev);
INIT_LIST_HEAD(&dev->napi_list);
INIT_LIST_HEAD(&dev->unreg_list);
INIT_LIST_HEAD(&dev->link_watch_list);
+ INIT_LIST_HEAD(&dev->upper_dev_list);
dev->priv_flags = IFF_XMIT_DST_RELEASE;
setup(dev);
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blobdiff