net: introduce netdev_change_features()

It will be needed by bonding and other drivers changing vlan_features
after ndo_init callback.

As a bonus, this includes kernel-doc for netdev_update_features().

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 26 insertions, 0 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 00d650c74800..1d9696a9ee4d 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2565,6 +2565,7 @@ u32 netdev_increment_features(u32 all, u32 one, u32 mask);
 u32 netdev_fix_features(struct net_device *dev, u32 features);
 int __netdev_update_features(struct net_device *dev);
 void netdev_update_features(struct net_device *dev);
+void netdev_change_features(struct net_device *dev);
 
 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
                                         struct net_device *dev);
diff --git a/net/core/dev.c b/net/core/dev.c
index 75898a32c038..ea23353e6251 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5289,6 +5289,14 @@ int __netdev_update_features(struct net_device *dev)
         return 1;
 }
 
+/**
+ *      netdev_update_features - recalculate device features
+ *      @dev: the device to check
+ *
+ *      Recalculate dev->features set and send notifications if it
+ *      has changed. Should be called after driver or hardware dependent
+ *      conditions might have changed that influence the features.
+ */
 void netdev_update_features(struct net_device *dev)
 {
         if (__netdev_update_features(dev))
@@ -5297,6 +5305,23 @@ void netdev_update_features(struct net_device *dev)
 EXPORT_SYMBOL(netdev_update_features);
 
 /**
+ *      netdev_change_features - recalculate device features
+ *      @dev: the device to check
+ *
+ *      Recalculate dev->features set and send notifications even
+ *      if they have not changed. Should be called instead of
+ *      netdev_update_features() if also dev->vlan_features might
+ *      have changed to allow the changes to be propagated to stacked
+ *      VLAN devices.
+ */
+void netdev_change_features(struct net_device *dev)
+{
+        __netdev_update_features(dev);
+        netdev_features_change(dev);
+}
+EXPORT_SYMBOL(netdev_change_features);
+
+/**
  *      netif_stacked_transfer_operstate -      transfer operstate
  *      @rootdev: the root or lower level device to transfer state from
  *      @dev: the device to transfer operstate to