e1000: Fixes for packet split related issues

Fixes for packet split related issues
  * On platforms where PAGE_SIZE > 4K, driver will use only required number of
    pages compared to always using 3 pages.
  * Packet split won't be used if the PAGE_SIZE is > 16K
  * Adds a statistics counter to splits.
  * Setting the non Null ptr to zero sized buffers to solve packet split
    receive descriptor error
  * When the no of pages needed is calculated, the header buffer is not
    included for a given MTU.

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/e1000/e1000_ethtool.c b/drivers/net/e1000/e1000_ethtool.c
index 6e7e34f..183b583 100644
--- a/drivers/net/e1000/e1000_ethtool.c
+++ b/drivers/net/e1000/e1000_ethtool.c
@@ -91,7 +91,8 @@
 	{ "tx_flow_control_xoff", E1000_STAT(stats.xofftxc) },
 	{ "rx_long_byte_count", E1000_STAT(stats.gorcl) },
 	{ "rx_csum_offload_good", E1000_STAT(hw_csum_good) },
-	{ "rx_csum_offload_errors", E1000_STAT(hw_csum_err) }
+	{ "rx_csum_offload_errors", E1000_STAT(hw_csum_err) },
+	{ "rx_header_split", E1000_STAT(rx_hdr_split) },
 };
 #define E1000_STATS_LEN	\
 	sizeof(e1000_gstrings_stats) / sizeof(struct e1000_stats)