i40e/i40evf: add Tx pre queue disable function

Add a function which indicates our intention to enable or disable a particular
Tx queue. Also add a function to notify the device's Tx unit that we're about
to enable or disable a Tx queue.

Change-ID: I6adf3cbb5bb3e3c984d1ec969e06577c19ef296d
Signed-off-by: Matt Jared <matthew.a.jared@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_register.h b/drivers/net/ethernet/intel/i40e/i40e_register.h
index 25c9286..947de98 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_register.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_register.h
@@ -1585,6 +1585,14 @@
 #define I40E_GLLAN_TSOMSK_M 0x000442DC
 #define I40E_GLLAN_TSOMSK_M_TCPMSKM_SHIFT 0
 #define I40E_GLLAN_TSOMSK_M_TCPMSKM_MASK (0xFFF << I40E_GLLAN_TSOMSK_M_TCPMSKM_SHIFT)
+#define I40E_GLLAN_TXPRE_QDIS(_i) (0x000E6500 + ((_i) * 4)) /* i=0..11 */
+#define I40E_GLLAN_TXPRE_QDIS_QINDX_SHIFT 0
+#define I40E_GLLAN_TXPRE_QDIS_QINDX_MASK (0x7FF << I40E_GLLAN_TXPRE_QDIS_QINDX_SHIFT)
+#define I40E_GLLAN_TXPRE_QDIS_SET_QDIS_SHIFT 30
+#define I40E_GLLAN_TXPRE_QDIS_SET_QDIS_MASK (0x1 << I40E_GLLAN_TXPRE_QDIS_SET_QDIS_SHIFT)
+#define I40E_GLLAN_TXPRE_QDIS_CLEAR_QDIS_SHIFT 31
+#define I40E_GLLAN_TXPRE_QDIS_CLEAR_QDIS_MASK (0x1 << I40E_GLLAN_TXPRE_QDIS_CLEAR_QDIS_SHIFT)
+
 #define I40E_PFLAN_QALLOC 0x001C0400
 #define I40E_PFLAN_QALLOC_FIRSTQ_SHIFT 0
 #define I40E_PFLAN_QALLOC_FIRSTQ_MASK (0x7FF << I40E_PFLAN_QALLOC_FIRSTQ_SHIFT)