ixgbe: Clean up priority based flow control

This change cleans up the logic in the priority based flow control
configuration routines.  Both the 82599 and 82598 based routines perform
similar functions however they are both arranged completely differently.
This patch goes over both of them to clean up the code.

In addition I am dropping the ixgbe_fc_pfc flow control mode and instead
just replacing it with checks for if priority flow control is enabled.
This allows us to maintain some of the link flow control information which
allows for an easier transition between link and priority flow control.

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, 40 insertions, 30 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index ea3cb71..0915e77 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -610,39 +610,50 @@ void ixgbe_unmap_and_free_tx_resource(struct ixgbe_ring *ring,
 	/* tx_buffer must be completely set up in the transmit path */
 }
 
-static void ixgbe_update_xoff_received(struct ixgbe_adapter *adapter)
+static void ixgbe_update_xoff_rx_lfc(struct ixgbe_adapter *adapter)
 {
 	struct ixgbe_hw *hw = &adapter->hw;
 	struct ixgbe_hw_stats *hwstats = &adapter->stats;
-	u32 data = 0;
-	u32 xoff[8] = {0};
 	int i;
+	u32 data;
 
-	if ((hw->fc.current_mode == ixgbe_fc_full) ||
-	    (hw->fc.current_mode == ixgbe_fc_rx_pause)) {
-		switch (hw->mac.type) {
-		case ixgbe_mac_82598EB:
-			data = IXGBE_READ_REG(hw, IXGBE_LXOFFRXC);
-			break;
-		default:
-			data = IXGBE_READ_REG(hw, IXGBE_LXOFFRXCNT);
-		}
-		hwstats->lxoffrxc += data;
+	if ((hw->fc.current_mode != ixgbe_fc_full) &&
+	    (hw->fc.current_mode != ixgbe_fc_rx_pause))
+		return;
 
-		/* refill credits (no tx hang) if we received xoff */
-		if (!data)
-			return;
+	switch (hw->mac.type) {
+	case ixgbe_mac_82598EB:
+		data = IXGBE_READ_REG(hw, IXGBE_LXOFFRXC);
+		break;
+	default:
+		data = IXGBE_READ_REG(hw, IXGBE_LXOFFRXCNT);
+	}
+	hwstats->lxoffrxc += data;
 
-		for (i = 0; i < adapter->num_tx_queues; i++)
-			clear_bit(__IXGBE_HANG_CHECK_ARMED,
-				  &adapter->tx_ring[i]->state);
+	/* refill credits (no tx hang) if we received xoff */
+	if (!data)
 		return;
-	} else if (((adapter->dcbx_cap & DCB_CAP_DCBX_VER_CEE) &&
-		    !(adapter->dcb_cfg.pfc_mode_enable)) ||
-		   ((adapter->dcbx_cap & DCB_CAP_DCBX_VER_IEEE) &&
-		    adapter->ixgbe_ieee_pfc &&
-		    !(adapter->ixgbe_ieee_pfc->pfc_en)))
+
+	for (i = 0; i < adapter->num_tx_queues; i++)
+		clear_bit(__IXGBE_HANG_CHECK_ARMED,
+			  &adapter->tx_ring[i]->state);
+}
+
+static void ixgbe_update_xoff_received(struct ixgbe_adapter *adapter)
+{
+	struct ixgbe_hw *hw = &adapter->hw;
+	struct ixgbe_hw_stats *hwstats = &adapter->stats;
+	u32 xoff[8] = {0};
+	int i;
+	bool pfc_en = adapter->dcb_cfg.pfc_mode_enable;
+
+	if (adapter->ixgbe_ieee_pfc)
+		pfc_en |= !!(adapter->ixgbe_ieee_pfc->pfc_en);
+
+	if (!(adapter->flags & IXGBE_FLAG_DCB_ENABLED) || !pfc_en) {
+		ixgbe_update_xoff_rx_lfc(adapter);
 		return;
+	}
 
 	/* update stats for each tc, only valid with PFC enabled */
 	for (i = 0; i < MAX_TX_PACKET_BUFFERS; i++) {
@@ -4403,9 +4414,6 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
 	/* default flow control settings */
 	hw->fc.requested_mode = ixgbe_fc_full;
 	hw->fc.current_mode = ixgbe_fc_full;	/* init for ethtool output */
-#ifdef CONFIG_DCB
-	adapter->last_lfc_mode = hw->fc.current_mode;
-#endif
 	ixgbe_pbthresh_setup(adapter);
 	hw->fc.pause_time = IXGBE_DEFAULT_FCPAUSE;
 	hw->fc.send_xon = true;
@@ -6542,15 +6550,17 @@ int ixgbe_setup_tc(struct net_device *dev, u8 tc)
 
 	if (tc) {
 		netdev_set_num_tc(dev, tc);
-		adapter->last_lfc_mode = adapter->hw.fc.current_mode;
 		adapter->flags |= IXGBE_FLAG_DCB_ENABLED;
 		adapter->flags &= ~IXGBE_FLAG_FDIR_HASH_CAPABLE;
 
-		if (adapter->hw.mac.type == ixgbe_mac_82598EB)
+		if (adapter->hw.mac.type == ixgbe_mac_82598EB) {
+			adapter->last_lfc_mode = adapter->hw.fc.requested_mode;
 			adapter->hw.fc.requested_mode = ixgbe_fc_none;
+		}
 	} else {
 		netdev_reset_tc(dev);
-		adapter->hw.fc.requested_mode = adapter->last_lfc_mode;
+		if (adapter->hw.mac.type == ixgbe_mac_82598EB)
+			adapter->hw.fc.requested_mode = adapter->last_lfc_mode;
 
 		adapter->flags &= ~IXGBE_FLAG_DCB_ENABLED;
 		adapter->flags |= IXGBE_FLAG_FDIR_HASH_CAPABLE;