ixgbe: drop ring->head, make ring->tail a pointer instead of offset

This change drops ring->head since it is not used in any hot-path and can
easily be determined using IXGBE_[RT]DH(ring->reg_idx).

It also changes ring->tail into a true pointer so we can avoid unnecessary
pointer math to find the location of the tail.

In addition I also dropped the setting of head and tail in
ixgbe_clean_[rx|tx]_ring. The only location that should be setting the head
and tail values is ixgbe_configure_[rx|tx]_ring and that is only while the
queue is disabled.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index 149cf26b2545..c993fc3ab8a5 100644
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -163,8 +163,7 @@ struct ixgbe_ring {
 
 #define IXGBE_RING_RX_PS_ENABLED                (u8)(1)
         u8 flags;                       /* per ring feature flags */
-        u16 head;
-        u16 tail;
+        u8 __iomem *tail;
 
         unsigned int total_bytes;
         unsigned int total_packets;