vxge: prefetch skb->data

This patch implements prefetching of skb->data from a copy of the pointer
in the descriptor (which is already in the L1 cache at this point).  This
improves netperf rx performance (netperf -L 0,0 -c -H 192.168.254.2 -- -M
131072 -m 131072) by 4.9% on a P4 Xeon host.

Signed-off-by: Benjamin LaHaise <ben.lahaise@neterion.com>
Signed-off-by: Sreenivasa Honnur <sreenivasa.honnur@neterion.com>
Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/vxge/vxge-main.h b/drivers/net/vxge/vxge-main.h
index 8b3989b..9c36b3a 100644
--- a/drivers/net/vxge/vxge-main.h
+++ b/drivers/net/vxge/vxge-main.h
@@ -378,6 +378,7 @@
 
 struct vxge_rx_priv {
 	struct sk_buff		*skb;
+	unsigned char		*skb_data;
 	dma_addr_t		data_dma;
 	dma_addr_t		data_size;
 };