i40e: take into account XDP Tx queues when stopping rings

Seth reported that on his side XDP traffic can not survive a round of
down/up against i40e interface. Dmesg output was telling us that we were
not able to disable the very first XDP ring. That was due to the fact
that in i40e_vsi_stop_rings() in a pre-work that is done before calling
i40e_vsi_wait_queues_disabled(), XDP Tx queues were not taken into the
account.

To fix this, let us distinguish between Rx and Tx queue boundaries and
take into the account XDP queues for Tx side.
Reported-by: Seth Forshee <sforshee@kernel.org>
Closes: https://lore.kernel.org/netdev/ZbkE7Ep1N1Ou17sA@do-x1extreme/
Fixes: 65662a8d ("i40e: Fix logic of disabling queues")
Tested-by: Seth Forshee <sforshee@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -4926,21 +4926,23 @@ int i40e_vsi_start_rings(struct i40e_vsi *vsi)
 void i40e_vsi_stop_rings(struct i40e_vsi *vsi)
 {
 	struct i40e_pf *pf = vsi->back;
-	int pf_q, q_end;
+	u32 pf_q, tx_q_end, rx_q_end;
 
 	/* When port TX is suspended, don't wait */
 	if (test_bit(__I40E_PORT_SUSPENDED, vsi->back->state))
 		return i40e_vsi_stop_rings_no_wait(vsi);
 
-	q_end = vsi->base_queue + vsi->num_queue_pairs;
-	for (pf_q = vsi->base_queue; pf_q < q_end; pf_q++)
-		i40e_pre_tx_queue_cfg(&pf->hw, (u32)pf_q, false);
+	tx_q_end = vsi->base_queue +
+		vsi->alloc_queue_pairs * (i40e_enabled_xdp_vsi(vsi) ? 2 : 1);
+	for (pf_q = vsi->base_queue; pf_q < tx_q_end; pf_q++)
+		i40e_pre_tx_queue_cfg(&pf->hw, pf_q, false);
 
-	for (pf_q = vsi->base_queue; pf_q < q_end; pf_q++)
+	rx_q_end = vsi->base_queue + vsi->num_queue_pairs;
+	for (pf_q = vsi->base_queue; pf_q < rx_q_end; pf_q++)
 		i40e_control_rx_q(pf, pf_q, false);
 
 	msleep(I40E_DISABLE_TX_GAP_MSEC);
-	for (pf_q = vsi->base_queue; pf_q < q_end; pf_q++)
+	for (pf_q = vsi->base_queue; pf_q < tx_q_end; pf_q++)
 		wr32(&pf->hw, I40E_QTX_ENA(pf_q), 0);
 
 	i40e_vsi_wait_queues_disabled(vsi);