net: qualcomm: rmnet: Add support for GRO

Add gro_cells so that rmnet devices can call gro_cells_receive
instead of netif_receive_skb.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qualcomm/rmnet/Kconfig

@@ -5,6 +5,7 @@
 menuconfig RMNET
 	tristate "RmNet MAP driver"
 	default n
+	select GRO_CELLS
 	---help---
 	  If you select this, you will enable the RMNET module which is used
 	  for handling data in the multiplexing and aggregation protocol (MAP)

drivers/net/ethernet/qualcomm/rmnet/rmnet_config.h

@@ -14,6 +14,7 @@
  */
 
 #include <linux/skbuff.h>
+#include <net/gro_cells.h>
 
 #ifndef _RMNET_CONFIG_H_
 #define _RMNET_CONFIG_H_
@@ -58,6 +59,7 @@ struct rmnet_priv {
 	u8 mux_id;
 	struct net_device *real_dev;
 	struct rmnet_pcpu_stats __percpu *pcpu_stats;
+	struct gro_cells gro_cells;
 };
 
 struct rmnet_port *rmnet_get_port(struct net_device *real_dev);

drivers/net/ethernet/qualcomm/rmnet/rmnet_handlers.c

@@ -46,13 +46,15 @@ static void rmnet_set_skb_proto(struct sk_buff *skb)
 static void
 rmnet_deliver_skb(struct sk_buff *skb)
 {
+	struct rmnet_priv *priv = netdev_priv(skb->dev);
+
 	skb_reset_transport_header(skb);
 	skb_reset_network_header(skb);
 	rmnet_vnd_rx_fixup(skb, skb->dev);
 
 	skb->pkt_type = PACKET_HOST;
 	skb_set_mac_header(skb, 0);
-	netif_receive_skb(skb);
+	gro_cells_receive(&priv->gro_cells, skb);
 }
 
 /* MAP handler */

drivers/net/ethernet/qualcomm/rmnet/rmnet_vnd.c

@@ -87,11 +87,18 @@ static int rmnet_vnd_get_iflink(const struct net_device *dev)
 static int rmnet_vnd_init(struct net_device *dev)
 {
 	struct rmnet_priv *priv = netdev_priv(dev);
+	int err;
 
 	priv->pcpu_stats = alloc_percpu(struct rmnet_pcpu_stats);
 	if (!priv->pcpu_stats)
 		return -ENOMEM;
 
+	err = gro_cells_init(&priv->gro_cells, dev);
+	if (err) {
+		free_percpu(priv->pcpu_stats);
+		return err;
+	}
+
 	return 0;
 }
 
@@ -99,6 +106,7 @@ static void rmnet_vnd_uninit(struct net_device *dev)
 {
 	struct rmnet_priv *priv = netdev_priv(dev);
 
+	gro_cells_destroy(&priv->gro_cells);
 	free_percpu(priv->pcpu_stats);
 }