ixgbe: DCB: enable RSS to be used with DCB

RSS had previously been disabled when DCB was enabled because
DCB was single queued per traffic class. Now that DCB implements
multiple Tx/Rx rings per traffic class enable RSS.

Here RSS hashes across the queues in the traffic class.

Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain.@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

2 files changed, 25 insertions, 9 deletions

diff --git a/drivers/net/ixgbe/ixgbe_dcb_nl.c b/drivers/net/ixgbe/ixgbe_dcb_nl.c
index b7b6db3bbd59..91ff51c53b04 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_nl.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_nl.c
@@ -129,7 +129,6 @@ static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
                         netdev->netdev_ops->ndo_stop(netdev);
                 ixgbe_clear_interrupt_scheme(adapter);
 
-                adapter->flags &= ~IXGBE_FLAG_RSS_ENABLED;
                 switch (adapter->hw.mac.type) {
                 case ixgbe_mac_82598EB:
                         adapter->last_lfc_mode = adapter->hw.fc.current_mode;
@@ -162,7 +161,6 @@ static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
                         adapter->temp_dcb_cfg.pfc_mode_enable = false;
                         adapter->dcb_cfg.pfc_mode_enable = false;
                         adapter->flags &= ~IXGBE_FLAG_DCB_ENABLED;
-                        adapter->flags |= IXGBE_FLAG_RSS_ENABLED;
                         switch (adapter->hw.mac.type) {
                         case ixgbe_mac_82599EB:
                         case ixgbe_mac_X540:
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 3ce0f4f956df..be2e145646bf 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -2892,17 +2892,20 @@ static void ixgbe_setup_mrqc(struct ixgbe_adapter *adapter)
                                         );
 
         switch (mask) {
+#ifdef CONFIG_IXGBE_DCB
+        case (IXGBE_FLAG_DCB_ENABLED | IXGBE_FLAG_RSS_ENABLED):
+                mrqc = IXGBE_MRQC_RTRSS8TCEN;
+                break;
+        case (IXGBE_FLAG_DCB_ENABLED):
+                mrqc = IXGBE_MRQC_RT8TCEN;
+                break;
+#endif /* CONFIG_IXGBE_DCB */
         case (IXGBE_FLAG_RSS_ENABLED):
                 mrqc = IXGBE_MRQC_RSSEN;
                 break;
         case (IXGBE_FLAG_SRIOV_ENABLED):
                 mrqc = IXGBE_MRQC_VMDQEN;
                 break;
-#ifdef CONFIG_IXGBE_DCB
-        case (IXGBE_FLAG_DCB_ENABLED):
-                mrqc = IXGBE_MRQC_RT8TCEN;
-                break;
-#endif /* CONFIG_IXGBE_DCB */
         default:
                 break;
         }
@@ -3672,6 +3675,23 @@ static void ixgbe_configure_dcb(struct ixgbe_adapter *adapter)
 
         /* reconfigure the hardware */
         ixgbe_dcb_hw_config(hw, &adapter->dcb_cfg);
+
+        /* Enable RSS Hash per TC */
+        if (hw->mac.type != ixgbe_mac_82598EB) {
+                int i;
+                u32 reg = 0;
+
+                for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
+                        u8 msb = 0;
+                        u8 cnt = adapter->netdev->tc_to_txq[i].count;
+
+                        while (cnt >>= 1)
+                                msb++;
+
+                        reg |= msb << IXGBE_RQTC_SHIFT_TC(i);
+                }
+                IXGBE_WRITE_REG(hw, IXGBE_RQTC, reg);
+        }
 }
 
 #endif
@@ -7343,8 +7363,6 @@ static int __devinit ixgbe_probe(struct pci_dev *pdev,
         if (adapter->flags & IXGBE_FLAG_SRIOV_ENABLED)
                 adapter->flags &= ~(IXGBE_FLAG_RSS_ENABLED |
                                     IXGBE_FLAG_DCB_ENABLED);
-        if (adapter->flags & IXGBE_FLAG_DCB_ENABLED)
-                adapter->flags &= ~IXGBE_FLAG_RSS_ENABLED;
 
 #ifdef CONFIG_IXGBE_DCB
         netdev->dcbnl_ops = &dcbnl_ops;