igb: add page recycling support

This patch adds support for page recycling by splitting the page into two
usable portions and tracking the reference count.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h
index ee08010..f41b999 100644
--- a/drivers/net/igb/igb.h
+++ b/drivers/net/igb/igb.h
@@ -125,6 +125,7 @@
 		struct {
 			struct page *page;
 			u64 page_dma;
+			unsigned int page_offset;
 		};
 	};
 };
@@ -163,9 +164,6 @@
 		};
 		/* RX */
 		struct {
-			/* arrays of page information for packet split */
-			struct sk_buff *pending_skb;
-			int pending_skb_page;
 			int no_itr_adjust;
 			struct igb_queue_stats rx_stats;
 			struct napi_struct napi;