ixgbe: update {P}FC thresholds to account for X540 and loopback

[deliverable/linux.git] / drivers / net / ethernet / intel / ixgbe / ixgbe_main.c

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 3594b09f4993a121d33cc110e89e32968f4b9108..ba703d30f3a956b75f0936690a18efcf7fa7faad 100644 (file)
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -3351,9 +3351,128 @@ static void ixgbe_configure_dcb(struct ixgbe_adapter *adapter)
                IXGBE_WRITE_REG(hw, IXGBE_RQTC, reg);
        }
 }
+#endif
+
+/* Additional bittime to account for IXGBE framing */
+#define IXGBE_ETH_FRAMING 20
+
+/*
+ * ixgbe_hpbthresh - calculate high water mark for flow control
+ *
+ * @adapter: board private structure to calculate for
+ * @pb - packet buffer to calculate
+ */
+static int ixgbe_hpbthresh(struct ixgbe_adapter *adapter, int pb)
+{
+       struct ixgbe_hw *hw = &adapter->hw;
+       struct net_device *dev = adapter->netdev;
+       int link, tc, kb, marker;
+       u32 dv_id, rx_pba;
+
+       /* Calculate max LAN frame size */
+       tc = link = dev->mtu + ETH_HLEN + ETH_FCS_LEN + IXGBE_ETH_FRAMING;
+
+#ifdef IXGBE_FCOE
+       /* FCoE traffic class uses FCOE jumbo frames */
+       if (dev->features & NETIF_F_FCOE_MTU) {
+               int fcoe_pb = 0;
 
+#ifdef CONFIG_IXGBE_DCB
+               fcoe_pb = netdev_get_prio_tc_map(dev, adapter->fcoe.up);
+
+#endif
+               if (fcoe_pb == pb && tc < IXGBE_FCOE_JUMBO_FRAME_SIZE)
+                       tc = IXGBE_FCOE_JUMBO_FRAME_SIZE;
+       }
 #endif
 
+       /* Calculate delay value for device */
+       switch (hw->mac.type) {
+       case ixgbe_mac_X540:
+               dv_id = IXGBE_DV_X540(link, tc);
+               break;
+       default:
+               dv_id = IXGBE_DV(link, tc);
+               break;
+       }
+
+       /* Loopback switch introduces additional latency */
+       if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)
+               dv_id += IXGBE_B2BT(tc);
+
+       /* Delay value is calculated in bit times convert to KB */
+       kb = IXGBE_BT2KB(dv_id);
+       rx_pba = IXGBE_READ_REG(hw, IXGBE_RXPBSIZE(pb)) >> 10;
+
+       marker = rx_pba - kb;
+
+       /* It is possible that the packet buffer is not large enough
+        * to provide required headroom. In this case throw an error
+        * to user and a do the best we can.
+        */
+       if (marker < 0) {
+               e_warn(drv, "Packet Buffer(%i) can not provide enough"
+                           "headroom to support flow control."
+                           "Decrease MTU or number of traffic classes\n", pb);
+               marker = tc + 1;
+       }
+
+       return marker;
+}
+
+/*
+ * ixgbe_lpbthresh - calculate low water mark for for flow control
+ *
+ * @adapter: board private structure to calculate for
+ * @pb - packet buffer to calculate
+ */
+static int ixgbe_lpbthresh(struct ixgbe_adapter *adapter)
+{
+       struct ixgbe_hw *hw = &adapter->hw;
+       struct net_device *dev = adapter->netdev;
+       int tc;
+       u32 dv_id;
+
+       /* Calculate max LAN frame size */
+       tc = dev->mtu + ETH_HLEN + ETH_FCS_LEN;
+
+       /* Calculate delay value for device */
+       switch (hw->mac.type) {
+       case ixgbe_mac_X540:
+               dv_id = IXGBE_LOW_DV_X540(tc);
+               break;
+       default:
+               dv_id = IXGBE_LOW_DV(tc);
+               break;
+       }
+
+       /* Delay value is calculated in bit times convert to KB */
+       return IXGBE_BT2KB(dv_id);
+}
+
+/*
+ * ixgbe_pbthresh_setup - calculate and setup high low water marks
+ */
+static void ixgbe_pbthresh_setup(struct ixgbe_adapter *adapter)
+{
+       struct ixgbe_hw *hw = &adapter->hw;
+       int num_tc = netdev_get_num_tc(adapter->netdev);
+       int i;
+
+       if (!num_tc)
+               num_tc = 1;
+
+       hw->fc.low_water = ixgbe_lpbthresh(adapter);
+
+       for (i = 0; i < num_tc; i++) {
+               hw->fc.high_water[i] = ixgbe_hpbthresh(adapter, i);
+
+               /* Low water marks must not be larger than high water marks */
+               if (hw->fc.low_water > hw->fc.high_water[i])
+                       hw->fc.low_water = 0;
+       }
+}
+
 static void ixgbe_configure_pb(struct ixgbe_adapter *adapter)
 {
        struct ixgbe_hw *hw = &adapter->hw;
@@ -3367,6 +3486,7 @@ static void ixgbe_configure_pb(struct ixgbe_adapter *adapter)
                hdrm = 0;
 
        hw->mac.ops.set_rxpba(hw, tc, hdrm, PBA_STRATEGY_EQUAL);
+       ixgbe_pbthresh_setup(adapter);
 }
 
 static void ixgbe_fdir_filter_restore(struct ixgbe_adapter *adapter)
@@ -4769,13 +4889,11 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
 {
        struct ixgbe_hw *hw = &adapter->hw;
        struct pci_dev *pdev = adapter->pdev;
-       struct net_device *dev = adapter->netdev;
        unsigned int rss;
 #ifdef CONFIG_IXGBE_DCB
        int j;
        struct tc_configuration *tc;
 #endif
-       int max_frame = dev->mtu + ETH_HLEN + ETH_FCS_LEN;
 
        /* PCI config space info */
 
@@ -4851,8 +4969,7 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
 #ifdef CONFIG_DCB
        adapter->last_lfc_mode = hw->fc.current_mode;
 #endif
-       hw->fc.high_water = FC_HIGH_WATER(max_frame);
-       hw->fc.low_water = FC_LOW_WATER(max_frame);
+       ixgbe_pbthresh_setup(adapter);
        hw->fc.pause_time = IXGBE_DEFAULT_FCPAUSE;
        hw->fc.send_xon = true;
        hw->fc.disable_fc_autoneg = false;
@@ -5119,9 +5236,6 @@ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
        /* must set new MTU before calling down or up */
        netdev->mtu = new_mtu;
 
-       hw->fc.high_water = FC_HIGH_WATER(max_frame);
-       hw->fc.low_water = FC_LOW_WATER(max_frame);
-
        if (netif_running(netdev))
                ixgbe_reinit_locked(adapter);