ixgbe: Update link flow control to correctly handle multiple packet buffer DCB

This change updates the link flow control configuration so that we
correctly set the link flow control settings for DCB.  Previously we would
have to call the fc_enable call 8 times, once for each packet buffer.  If
we move that logic into the fc_enable call itself we can avoid multiple
unnecessary register writes.

This change also corrects an issue in which we were only shifting the water
marks for 82599 parts by 6 instead of 10.  This was resulting in us only
using 1/16 of the packet buffer when flow control was enabled.

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, 31 insertions, 30 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c
index badcf821d89a..42537336110c 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c
@@ -324,24 +324,33 @@ out:
 /**
  *  ixgbe_fc_enable_82598 - Enable flow control
  *  @hw: pointer to hardware structure
- *  @packetbuf_num: packet buffer number (0-7)
  *
  *  Enable flow control according to the current settings.
  **/
-static s32 ixgbe_fc_enable_82598(struct ixgbe_hw *hw, s32 packetbuf_num)
+static s32 ixgbe_fc_enable_82598(struct ixgbe_hw *hw)
 {
 	s32 ret_val = 0;
 	u32 fctrl_reg;
 	u32 rmcs_reg;
 	u32 reg;
+	u32 fcrtl, fcrth;
 	u32 link_speed = 0;
+	int i;
 	bool link_up;
 
-#ifdef CONFIG_DCB
-	if (hw->fc.requested_mode == ixgbe_fc_pfc)
+	/*
+	 * Validate the water mark configuration for packet buffer 0.  Zero
+	 * water marks indicate that the packet buffer was not configured
+	 * and the watermarks for packet buffer 0 should always be configured.
+	 */
+	if (!hw->fc.low_water ||
+	    !hw->fc.high_water[0] ||
+	    !hw->fc.pause_time) {
+		hw_dbg(hw, "Invalid water mark configuration\n");
+		ret_val = IXGBE_ERR_INVALID_LINK_SETTINGS;
 		goto out;
+	}
 
-#endif /* CONFIG_DCB */
 	/*
 	 * On 82598 having Rx FC on causes resets while doing 1G
 	 * so if it's on turn it off once we know link_speed. For
@@ -380,9 +389,6 @@ static s32 ixgbe_fc_enable_82598(struct ixgbe_hw *hw, s32 packetbuf_num)
 	 * 2: Tx flow control is enabled (we can send pause frames but
 	 *     we do not support receiving pause frames).
 	 * 3: Both Rx and Tx flow control (symmetric) are enabled.
-#ifdef CONFIG_DCB
-	 * 4: Priority Flow Control is enabled.
-#endif
 	 * other: Invalid.
 	 */
 	switch (hw->fc.current_mode) {
@@ -415,11 +421,6 @@ static s32 ixgbe_fc_enable_82598(struct ixgbe_hw *hw, s32 packetbuf_num)
 		fctrl_reg |= IXGBE_FCTRL_RFCE;
 		rmcs_reg |= IXGBE_RMCS_TFCE_802_3X;
 		break;
-#ifdef CONFIG_DCB
-	case ixgbe_fc_pfc:
-		goto out;
-		break;
-#endif /* CONFIG_DCB */
 	default:
 		hw_dbg(hw, "Flow control param set incorrectly\n");
 		ret_val = IXGBE_ERR_CONFIG;
@@ -432,29 +433,29 @@ static s32 ixgbe_fc_enable_82598(struct ixgbe_hw *hw, s32 packetbuf_num)
 	IXGBE_WRITE_REG(hw, IXGBE_FCTRL, fctrl_reg);
 	IXGBE_WRITE_REG(hw, IXGBE_RMCS, rmcs_reg);
 
-	/* Set up and enable Rx high/low water mark thresholds, enable XON. */
-	if (hw->fc.current_mode & ixgbe_fc_tx_pause) {
-		reg = hw->fc.low_water << 6;
-		if (hw->fc.send_xon)
-			reg |= IXGBE_FCRTL_XONE;
+	fcrtl = (hw->fc.low_water << 10) | IXGBE_FCRTL_XONE;
 
-		IXGBE_WRITE_REG(hw, IXGBE_FCRTL(packetbuf_num), reg);
-
-		reg = hw->fc.high_water[packetbuf_num] << 6;
-		reg |= IXGBE_FCRTH_FCEN;
+	/* Set up and enable Rx high/low water mark thresholds, enable XON. */
+	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
+		if ((hw->fc.current_mode & ixgbe_fc_tx_pause) &&
+		    hw->fc.high_water[i]) {
+			fcrth = (hw->fc.high_water[i] << 10) | IXGBE_FCRTH_FCEN;
+			IXGBE_WRITE_REG(hw, IXGBE_FCRTL(i), fcrtl);
+			IXGBE_WRITE_REG(hw, IXGBE_FCRTH(i), fcrth);
+		} else {
+			IXGBE_WRITE_REG(hw, IXGBE_FCRTL(i), 0);
+			IXGBE_WRITE_REG(hw, IXGBE_FCRTH(i), 0);
+		}
 
-		IXGBE_WRITE_REG(hw, IXGBE_FCRTH(packetbuf_num), reg);
 	}
 
 	/* Configure pause time (2 TCs per register) */
-	reg = IXGBE_READ_REG(hw, IXGBE_FCTTV(packetbuf_num / 2));
-	if ((packetbuf_num & 1) == 0)
-		reg = (reg & 0xFFFF0000) | hw->fc.pause_time;
-	else
-		reg = (reg & 0x0000FFFF) | (hw->fc.pause_time << 16);
-	IXGBE_WRITE_REG(hw, IXGBE_FCTTV(packetbuf_num / 2), reg);
+	reg = hw->fc.pause_time * 0x00010001;
+	for (i = 0; i < (MAX_TRAFFIC_CLASS / 2); i++)
+		IXGBE_WRITE_REG(hw, IXGBE_FCTTV(i), reg);
 
-	IXGBE_WRITE_REG(hw, IXGBE_FCRTV, (hw->fc.pause_time >> 1));
+	/* Configure flow control refresh threshold value */
+	IXGBE_WRITE_REG(hw, IXGBE_FCRTV, hw->fc.pause_time / 2);
 
 out:
 	return ret_val;