net: Add layer 2 hardware acceleration operations for macvlan devices

Add a operations structure that allows a network interface to export
the fact that it supports package forwarding in hardware between
physical interfaces and other mac layer devices assigned to it (such
as macvlans). This operaions structure can be used by virtual mac
devices to bypass software switching so that forwarding can be done
in hardware more efficiently.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 15 insertions, 6 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 0e6136546a8c..8ffc52e01ece 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2538,7 +2538,7 @@ static inline int skb_needs_linearize(struct sk_buff *skb,
 }
 
 int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
-                        struct netdev_queue *txq)
+                        struct netdev_queue *txq, void *accel_priv)
 {
         const struct net_device_ops *ops = dev->netdev_ops;
         int rc = NETDEV_TX_OK;
@@ -2604,9 +2604,13 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev,
                         dev_queue_xmit_nit(skb, dev);
 
                 skb_len = skb->len;
-                rc = ops->ndo_start_xmit(skb, dev);
+                if (accel_priv)
+                        rc = ops->ndo_dfwd_start_xmit(skb, dev, accel_priv);
+                else
+                        rc = ops->ndo_start_xmit(skb, dev);
+
                 trace_net_dev_xmit(skb, rc, dev, skb_len);
-                if (rc == NETDEV_TX_OK)
+                if (rc == NETDEV_TX_OK && txq)
                         txq_trans_update(txq);
                 return rc;
         }
@@ -2622,7 +2626,10 @@ gso:
                         dev_queue_xmit_nit(nskb, dev);
 
                 skb_len = nskb->len;
-                rc = ops->ndo_start_xmit(nskb, dev);
+                if (accel_priv)
+                        rc = ops->ndo_dfwd_start_xmit(nskb, dev, accel_priv);
+                else
+                        rc = ops->ndo_start_xmit(nskb, dev);
                 trace_net_dev_xmit(nskb, rc, dev, skb_len);
                 if (unlikely(rc != NETDEV_TX_OK)) {
                         if (rc & ~NETDEV_TX_MASK)
@@ -2647,6 +2654,7 @@ out_kfree_skb:
 out:
         return rc;
 }
+EXPORT_SYMBOL_GPL(dev_hard_start_xmit);
 
 static void qdisc_pkt_len_init(struct sk_buff *skb)
 {
@@ -2854,7 +2862,7 @@ int dev_queue_xmit(struct sk_buff *skb)
 
                         if (!netif_xmit_stopped(txq)) {
                                 __this_cpu_inc(xmit_recursion);
-                                rc = dev_hard_start_xmit(skb, dev, txq);
+                                rc = dev_hard_start_xmit(skb, dev, txq, NULL);
                                 __this_cpu_dec(xmit_recursion);
                                 if (dev_xmit_complete(rc)) {
                                         HARD_TX_UNLOCK(dev, txq);
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 862989898f61..30071dec287a 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -96,6 +96,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN]
         [NETIF_F_LOOPBACK_BIT] =         "loopback",
         [NETIF_F_RXFCS_BIT] =            "rx-fcs",
         [NETIF_F_RXALL_BIT] =            "rx-all",
+        [NETIF_F_HW_L2FW_DOFFLOAD_BIT] = "l2-fwd-offload",
 };
 
 static int ethtool_get_features(struct net_device *dev, void __user *useraddr)
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 7fc899a943a8..922a09406ba7 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -126,7 +126,7 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
 
         HARD_TX_LOCK(dev, txq, smp_processor_id());
         if (!netif_xmit_frozen_or_stopped(txq))
-                ret = dev_hard_start_xmit(skb, dev, txq);
+                ret = dev_hard_start_xmit(skb, dev, txq, NULL);
 
         HARD_TX_UNLOCK(dev, txq);