+
+static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
+ struct netdev_hw_addr *ha, bool global,
+ bool sync)
+{
+ if (global && !ha->global_use)
+ return -ENOENT;
+
+ if (sync && !ha->synced)
+ return -ENOENT;
+
+ if (global)
+ ha->global_use = false;
+
+ if (sync)
+ ha->synced--;
+
+ if (--ha->refcount)
+ return 0;
+ list_del_rcu(&ha->list);
+ kfree_rcu(ha, rcu_head);
+ list->count--;
+ return 0;
+}
+
+/**
+ * __hw_addr_sync_dev - Synchonize device's multicast list
+ * @list: address list to syncronize
+ * @dev: device to sync
+ * @sync: function to call if address should be added
+ * @unsync: function to call if address should be removed
+ *
+ * This funciton is intended to be called from the ndo_set_rx_mode
+ * function of devices that require explicit address add/remove
+ * notifications. The unsync function may be NULL in which case
+ * the addresses requiring removal will simply be removed without
+ * any notification to the device.
+ **/
+#define __hw_addr_sync_dev LINUX_BACKPORT(__hw_addr_sync_dev)
+int __hw_addr_sync_dev(struct netdev_hw_addr_list *list,
+ struct net_device *dev,
+ int (*sync)(struct net_device *, const unsigned char *),
+ int (*unsync)(struct net_device *,
+ const unsigned char *))
+{
+ struct netdev_hw_addr *ha, *tmp;
+ int err;
+
+ /* first go through and flush out any stale entries */
+ list_for_each_entry_safe(ha, tmp, &list->list, list) {
+ if (!ha->sync_cnt || ha->refcount != 1)
+ continue;
+
+ /* if unsync is defined and fails defer unsyncing address */
+ if (unsync && unsync(dev, ha->addr))
+ continue;
+
+ ha->sync_cnt--;
+ __hw_addr_del_entry(list, ha, false, false);
+ }
+
+ /* go through and sync new entries to the list */
+ list_for_each_entry_safe(ha, tmp, &list->list, list) {
+ if (ha->sync_cnt)
+ continue;
+
+ err = sync(dev, ha->addr);
+ if (err)
+ return err;
+
+ ha->sync_cnt++;
+ ha->refcount++;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(__hw_addr_sync_dev);