tunnels: prepare percpu accounting

Tunnels are going to use percpu for their accounting.

They are going to use a new tstats field in net_device.

skb_tunnel_rx() is changed to be a wrapper around __skb_tunnel_rx()

IPTUNNEL_XMIT() is changed to be a wrapper around __IPTUNNEL_XMIT()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ipip.h b/include/net/ipip.h
index 65caea8..58abbf9 100644
--- a/include/net/ipip.h
+++ b/include/net/ipip.h
@@ -45,7 +45,7 @@
 	struct rcu_head			rcu_head;
 };
 
-#define IPTUNNEL_XMIT() do {						\
+#define __IPTUNNEL_XMIT(stats1, stats2) do {				\
 	int err;							\
 	int pkt_len = skb->len - skb_transport_offset(skb);		\
 									\
@@ -54,12 +54,14 @@
 									\
 	err = ip_local_out(skb);					\
 	if (likely(net_xmit_eval(err) == 0)) {				\
-		txq->tx_bytes += pkt_len;				\
-		txq->tx_packets++;					\
+		(stats1)->tx_bytes += pkt_len;				\
+		(stats1)->tx_packets++;					\
 	} else {							\
-		stats->tx_errors++;					\
-		stats->tx_aborted_errors++;				\
+		(stats2)->tx_errors++;					\
+		(stats2)->tx_aborted_errors++;				\
 	}								\
 } while (0)
 
+#define IPTUNNEL_XMIT() __IPTUNNEL_XMIT(txq, stats)
+
 #endif