netdev_get_fwd_headroom
unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
dev_hr = netdev_get_fwd_headroom(dev);
dev_headroom = netdev_get_fwd_headroom(dev);
new_headroom = netdev_get_fwd_headroom(vport->dev);
if (netdev_get_fwd_headroom(vport->dev) == dp->max_headroom)