[NET]: Added GSO toggle

This patch adds a generic segmentation offload toggle that can be turned
on/off for each net device.  For now it only supports in TCPv4.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 47 insertions, 6 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index cf2abeca92a0..c6310aef5ab0 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -411,6 +411,8 @@ struct ethtool_ops {
 #define ETHTOOL_GPERMADDR       0x00000020 /* Get permanent hardware address */
 #define ETHTOOL_GUFO            0x00000021 /* Get UFO enable (ethtool_value) */
 #define ETHTOOL_SUFO            0x00000022 /* Set UFO enable (ethtool_value) */
+#define ETHTOOL_GGSO            0x00000023 /* Get GSO enable (ethtool_value) */
+#define ETHTOOL_SGSO            0x00000024 /* Set GSO enable (ethtool_value) */
 
 /* compatibility with older code */
 #define SPARC_ETH_GSET          ETHTOOL_GSET
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index b4eae18390cc..bc747e5d7138 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -308,6 +308,7 @@ struct net_device
 #define NETIF_F_HW_VLAN_RX      256     /* Receive VLAN hw acceleration */
 #define NETIF_F_HW_VLAN_FILTER  512     /* Receive filtering on VLAN */
 #define NETIF_F_VLAN_CHALLENGED 1024    /* Device cannot handle VLAN packets */
+#define NETIF_F_GSO             2048    /* Enable software GSO. */
 #define NETIF_F_LLTX            4096    /* LockLess TX */
 
         /* Segmentation offload features */
diff --git a/include/net/sock.h b/include/net/sock.h
index d10dfecb6cbd..a897f05de3b5 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1030,9 +1030,13 @@ static inline void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
 {
         __sk_dst_set(sk, dst);
         sk->sk_route_caps = dst->dev->features;
+        if (sk->sk_route_caps & NETIF_F_GSO)
+                sk->sk_route_caps |= NETIF_F_TSO;
         if (sk->sk_route_caps & NETIF_F_TSO) {
                 if (sock_flag(sk, SOCK_NO_LARGESEND) || dst->header_len)
                         sk->sk_route_caps &= ~NETIF_F_TSO;
+                else 
+                        sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
         }
 }
 
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index fdec773f5b52..07956ecf545e 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -376,15 +376,20 @@ void br_features_recompute(struct net_bridge *br)
         features = br->feature_mask & ~NETIF_F_ALL_CSUM;
 
         list_for_each_entry(p, &br->port_list, list) {
-                if (checksum & NETIF_F_NO_CSUM &&
-                    !(p->dev->features & NETIF_F_NO_CSUM))
+                unsigned long feature = p->dev->features;
+
+                if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM))
                         checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM;
-                if (checksum & NETIF_F_HW_CSUM &&
-                    !(p->dev->features & NETIF_F_HW_CSUM))
+                if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM))
                         checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM;
-                if (!(p->dev->features & NETIF_F_IP_CSUM))
+                if (!(feature & NETIF_F_IP_CSUM))
                         checksum = 0;
-                features &= p->dev->features;
+
+                if (feature & NETIF_F_GSO)
+                        feature |= NETIF_F_TSO;
+                feature |= NETIF_F_GSO;
+
+                features &= feature;
         }
 
         br->dev->features = features | checksum | NETIF_F_LLTX;
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 33ce7ed6afc6..27ce1683caf5 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -614,6 +614,29 @@ static int ethtool_set_ufo(struct net_device *dev, char __user *useraddr)
         return dev->ethtool_ops->set_ufo(dev, edata.data);
 }
 
+static int ethtool_get_gso(struct net_device *dev, char __user *useraddr)
+{
+        struct ethtool_value edata = { ETHTOOL_GGSO };
+
+        edata.data = dev->features & NETIF_F_GSO;
+        if (copy_to_user(useraddr, &edata, sizeof(edata)))
+                 return -EFAULT;
+        return 0;
+}
+
+static int ethtool_set_gso(struct net_device *dev, char __user *useraddr)
+{
+        struct ethtool_value edata;
+
+        if (copy_from_user(&edata, useraddr, sizeof(edata)))
+                return -EFAULT;
+        if (edata.data)
+                dev->features |= NETIF_F_GSO;
+        else
+                dev->features &= ~NETIF_F_GSO;
+        return 0;
+}
+
 static int ethtool_self_test(struct net_device *dev, char __user *useraddr)
 {
         struct ethtool_test test;
@@ -905,6 +928,12 @@ int dev_ethtool(struct ifreq *ifr)
         case ETHTOOL_SUFO:
                 rc = ethtool_set_ufo(dev, useraddr);
                 break;
+        case ETHTOOL_GGSO:
+                rc = ethtool_get_gso(dev, useraddr);
+                break;
+        case ETHTOOL_SGSO:
+                rc = ethtool_set_gso(dev, useraddr);
+                break;
         default:
                 rc =  -EOPNOTSUPP;
         }