[VLAN]: Propagate selected feature bits to VLAN devices

Propagate feature bits from the NETDEV_FEAT_CHANGE notifier. For now
only TSO is propagated for devices that announce their ability to
support TSO in combination with VLAN accel by setting the NETIF_F_VLAN_TSO
flag.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 41 insertions, 2 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index b11e6e19e96c..2b0266484c84 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -514,10 +514,12 @@ struct net_device
 #define NETIF_F_NETNS_LOCAL     8192    /* Does not change network namespaces */
 #define NETIF_F_MULTI_QUEUE     16384   /* Has multiple TX/RX queues */
 #define NETIF_F_LRO             32768   /* large receive offload */
+#define NETIF_F_VLAN_TSO        65536   /* Supports TSO for VLANs */
+#define NETIF_F_VLAN_CSUM       131072  /* Supports TX checksumming for VLANs */
 
         /* Segmentation offload features */
-#define NETIF_F_GSO_SHIFT       16
-#define NETIF_F_GSO_MASK        0xffff0000
+#define NETIF_F_GSO_SHIFT       20
+#define NETIF_F_GSO_MASK        0xfff00000
 #define NETIF_F_TSO             (SKB_GSO_TCPV4 << NETIF_F_GSO_SHIFT)
 #define NETIF_F_UFO             (SKB_GSO_UDP << NETIF_F_GSO_SHIFT)
 #define NETIF_F_GSO_ROBUST      (SKB_GSO_DODGY << NETIF_F_GSO_SHIFT)
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index b934159a6f07..51961300b586 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -382,6 +382,24 @@ static void vlan_sync_address(struct net_device *dev,
         memcpy(vlan->real_dev_addr, dev->dev_addr, ETH_ALEN);
 }
 
+static void vlan_transfer_features(struct net_device *dev,
+                                   struct net_device *vlandev)
+{
+        unsigned long old_features = vlandev->features;
+
+        if (dev->features & NETIF_F_VLAN_TSO) {
+                vlandev->features &= ~VLAN_TSO_FEATURES;
+                vlandev->features |= dev->features & VLAN_TSO_FEATURES;
+        }
+        if (dev->features & NETIF_F_VLAN_CSUM) {
+                vlandev->features &= ~NETIF_F_ALL_CSUM;
+                vlandev->features |= dev->features & NETIF_F_ALL_CSUM;
+        }
+
+        if (old_features != vlandev->features)
+                netdev_features_change(vlandev);
+}
+
 static void __vlan_device_event(struct net_device *dev, unsigned long event)
 {
         switch (event) {
@@ -448,6 +466,18 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
                 }
                 break;
 
+        case NETDEV_FEAT_CHANGE:
+                /* Propagate device features to underlying device */
+                for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
+                        vlandev = vlan_group_get_device(grp, i);
+                        if (!vlandev)
+                                continue;
+
+                        vlan_transfer_features(dev, vlandev);
+                }
+
+                break;
+
         case NETDEV_DOWN:
                 /* Put all VLANs for this dev in the down state too.  */
                 for (i = 0; i < VLAN_GROUP_ARRAY_LEN; i++) {
diff --git a/net/8021q/vlan.h b/net/8021q/vlan.h
index 5229a72c7ea1..79625696e86a 100644
--- a/net/8021q/vlan.h
+++ b/net/8021q/vlan.h
@@ -7,6 +7,8 @@
 #define VLAN_GRP_HASH_SIZE      (1 << VLAN_GRP_HASH_SHIFT)
 #define VLAN_GRP_HASH_MASK      (VLAN_GRP_HASH_SIZE - 1)
 
+#define VLAN_TSO_FEATURES       (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_SG)
+
 /*  Find a VLAN device by the MAC address of its Ethernet device, and
  *  it's VLAN ID.  The default configuration is to have VLAN's scope
  *  to be box-wide, so the MAC will be ignored.  The mac will only be
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index c961f0826005..b1cfbaa88db2 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -663,6 +663,11 @@ static int vlan_dev_init(struct net_device *dev)
                                           (1<<__LINK_STATE_DORMANT))) |
                       (1<<__LINK_STATE_PRESENT);
 
+        if (real_dev->features & NETIF_F_VLAN_TSO)
+                dev->features |= real_dev->features & VLAN_TSO_FEATURES;
+        if (real_dev->features & NETIF_F_VLAN_CSUM)
+                dev->features |= real_dev->features & NETIF_F_ALL_CSUM;
+
         /* ipv6 shared card related stuff */
         dev->dev_id = real_dev->dev_id;