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, 45 insertions, 48 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c
index 65913c5a616e..4eac80d01857 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb_82599.c
@@ -211,24 +211,42 @@ s32 ixgbe_dcb_config_tx_data_arbiter_82599(struct ixgbe_hw *hw,
  */
 s32 ixgbe_dcb_config_pfc_82599(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
 {
-	u32 i, j, reg;
+	u32 i, j, fcrtl, reg;
 	u8 max_tc = 0;
 
-	for (i = 0; i < MAX_USER_PRIORITY; i++)
+	/* Enable Transmit Priority Flow Control */
+	IXGBE_WRITE_REG(hw, IXGBE_FCCFG, IXGBE_FCCFG_TFCE_PRIORITY);
+
+	/* Enable Receive Priority Flow Control */
+	reg = IXGBE_READ_REG(hw, IXGBE_MFLCN);
+	reg |= IXGBE_MFLCN_DPF;
+
+	/*
+	 * X540 supports per TC Rx priority flow control.  So
+	 * clear all TCs and only enable those that should be
+	 * enabled.
+	 */
+	reg &= ~(IXGBE_MFLCN_RPFCE_MASK | IXGBE_MFLCN_RFCE);
+
+	if (hw->mac.type == ixgbe_mac_X540)
+		reg |= pfc_en << IXGBE_MFLCN_RPFCE_SHIFT;
+
+	if (pfc_en)
+		reg |= IXGBE_MFLCN_RPFCE;
+
+	IXGBE_WRITE_REG(hw, IXGBE_MFLCN, reg);
+
+	for (i = 0; i < MAX_USER_PRIORITY; i++) {
 		if (prio_tc[i] > max_tc)
 			max_tc = prio_tc[i];
+	}
+
+	fcrtl = (hw->fc.low_water << 10) | IXGBE_FCRTL_XONE;
 
 	/* Configure PFC Tx thresholds per TC */
-	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
+	for (i = 0; i <= max_tc; i++) {
 		int enabled = 0;
 
-		if (i > max_tc) {
-			reg = 0;
-			IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), reg);
-			IXGBE_WRITE_REG(hw, IXGBE_FCRTH_82599(i), reg);
-			continue;
-		}
-
 		for (j = 0; j < MAX_USER_PRIORITY; j++) {
 			if ((prio_tc[j] == i) && (pfc_en & (1 << j))) {
 				enabled = 1;
@@ -236,50 +254,29 @@ s32 ixgbe_dcb_config_pfc_82599(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
 			}
 		}
 
-		reg = hw->fc.low_water << 10;
-
-		if (enabled)
-			reg |= IXGBE_FCRTL_XONE;
-		IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), reg);
+		if (enabled) {
+			reg = (hw->fc.high_water[i] << 10) | IXGBE_FCRTH_FCEN;
+			IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), fcrtl);
+		} else {
+			reg = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(i)) - 32;
+			IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), 0);
+		}
 
-		reg = hw->fc.high_water[i] << 10;
-		if (enabled)
-			reg |= IXGBE_FCRTH_FCEN;
 		IXGBE_WRITE_REG(hw, IXGBE_FCRTH_82599(i), reg);
 	}
 
-	if (pfc_en) {
-		/* Configure pause time (2 TCs per register) */
-		reg = hw->fc.pause_time | (hw->fc.pause_time << 16);
-		for (i = 0; i < (MAX_TRAFFIC_CLASS / 2); i++)
-			IXGBE_WRITE_REG(hw, IXGBE_FCTTV(i), reg);
-
-		/* Configure flow control refresh threshold value */
-		IXGBE_WRITE_REG(hw, IXGBE_FCRTV, hw->fc.pause_time / 2);
-
-
-		reg = IXGBE_FCCFG_TFCE_PRIORITY;
-		IXGBE_WRITE_REG(hw, IXGBE_FCCFG, reg);
-		/*
-		 * Enable Receive PFC
-		 * 82599 will always honor XOFF frames we receive when
-		 * we are in PFC mode however X540 only honors enabled
-		 * traffic classes.
-		 */
-		reg = IXGBE_READ_REG(hw, IXGBE_MFLCN);
-		reg &= ~IXGBE_MFLCN_RFCE;
-		reg |= IXGBE_MFLCN_RPFCE | IXGBE_MFLCN_DPF;
-
-		if (hw->mac.type == ixgbe_mac_X540) {
-			reg &= ~IXGBE_MFLCN_RPFCE_MASK;
-			reg |= pfc_en << IXGBE_MFLCN_RPFCE_SHIFT;
-		}
+	for (; i < MAX_TRAFFIC_CLASS; i++) {
+		IXGBE_WRITE_REG(hw, IXGBE_FCRTL_82599(i), 0);
+		IXGBE_WRITE_REG(hw, IXGBE_FCRTH_82599(i), 0);
+	}
 
-		IXGBE_WRITE_REG(hw, IXGBE_MFLCN, reg);
+	/* Configure pause time (2 TCs per register) */
+	reg = hw->fc.pause_time * 0x00010001;
+	for (i = 0; i < (MAX_TRAFFIC_CLASS / 2); i++)
+		IXGBE_WRITE_REG(hw, IXGBE_FCTTV(i), reg);
 
-	} else {
-		hw->mac.ops.fc_enable(hw);
-	}
+	/* Configure flow control refresh threshold value */
+	IXGBE_WRITE_REG(hw, IXGBE_FCRTV, hw->fc.pause_time / 2);
 
 	return 0;
 }