net: propagate NETIF_F_HIGHDMA to vlans

Automatically allows vlans to get NETIF_F_HIGHDMA if underlying device
supports it.

On 32bit arches (and more precisely if CONFIG_HIGHMEM is enabled), it
can help to reduce cost of illegal_highdma() and __skb_linearize()
calls.

Tested on tg3 , bnx2, bonding, this worked very well.

This is a generalization of a patch provided by Yi Zou & Jeff Kirsher.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2010-09-23 00:46:11 +00:00 committed by David S. Miller
parent bba50b99b2
commit c5256c5123
1 changed files with 4 additions and 3 deletions

View File

@ -5058,10 +5058,11 @@ int register_netdevice(struct net_device *dev)
if (dev->features & NETIF_F_SG)
dev->features |= NETIF_F_GSO;
/* Enable GRO for vlans by default if dev->features has GRO also.
* vlan_dev_init() will do the dev->features check.
/* Enable GRO and NETIF_F_HIGHDMA for vlans by default,
* vlan_dev_init() will do the dev->features check, so these features
* are enabled only if supported by underlying device.
*/
dev->vlan_features |= NETIF_F_GRO;
dev->vlan_features |= (NETIF_F_GRO | NETIF_F_HIGHDMA);
ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
ret = notifier_to_errno(ret);