vxge: improve tx performance by using mmiowb() instead of wmb()

wmb() is extremely heavy on x86.  The semantics required in the driver are
provided by mmiowb(), so use that and improve tx performance on P4 Xeons by
5-10%.

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-traffic.c b/drivers/net/vxge/vxge-traffic.c
index c249cd25a5d0415957dffbb606bd218cda76c5b9..0efb769894ef42b01a667b589e7182b3f09a65f8 100644 (file)
--- a/drivers/net/vxge/vxge-traffic.c
+++ b/drivers/net/vxge/vxge-traffic.c
@@ -1070,11 +1070,11 @@ static void __vxge_hw_non_offload_db_post(struct __vxge_hw_fifo *fifo,
                VXGE_HW_NODBW_GET_NO_SNOOP(no_snoop),
                &fifo->nofl_db->control_0);
 
-       wmb();
+       mmiowb();
 
        writeq(txdl_ptr, &fifo->nofl_db->txdl_ptr);
-       wmb();
 
+       mmiowb();
 }
 
 /**