ixgbe: Allow Priority Flow Control settings to survive a device reset

When changing DCB parameters, ixgbe needs to have the MAC reset.  The way
the flow control code is setup today, PFC will be disabled on a reset.
This patch adds a new flow control type for PFC, and then has the netlink
layer take care of toggling which type of flow control to enable.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

5 files changed, 26 insertions, 6 deletions

diff --git a/drivers/net/ixgbe/ixgbe_common.c b/drivers/net/ixgbe/ixgbe_common.c
index 245db0e712e7..8cfd3fd309a0 100644
--- a/drivers/net/ixgbe/ixgbe_common.c
+++ b/drivers/net/ixgbe/ixgbe_common.c
@@ -1654,9 +1654,10 @@ s32 ixgbe_fc_enable(struct ixgbe_hw *hw, s32 packetbuf_num)
          * 0: Flow control is completely disabled
          * 1: Rx flow control is enabled (we can receive pause frames,
          *    but not send pause frames).
-         * 2:  Tx flow control is enabled (we can send pause frames but
-         *     we do not support receiving pause frames).
+         * 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.
+         * 4: Priority Flow Control is enabled.
          * other: Invalid.
          */
         switch (hw->fc.current_mode) {
@@ -1686,6 +1687,11 @@ s32 ixgbe_fc_enable(struct ixgbe_hw *hw, s32 packetbuf_num)
                 mflcn_reg |= IXGBE_MFLCN_RFCE;
                 fccfg_reg |= IXGBE_FCCFG_TFCE_802_3X;
                 break;
+#ifdef CONFIG_DCB
+        case ixgbe_fc_pfc:
+                goto out;
+                break;
+#endif
         default:
                 hw_dbg(hw, "Flow control param set incorrectly\n");
                 ret_val = -IXGBE_ERR_CONFIG;
@@ -1746,6 +1752,7 @@ s32 ixgbe_fc_autoneg(struct ixgbe_hw *hw)
          * 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.
+         * 4:  Priority Flow Control is enabled.
          * other: Invalid.
          */
         switch (hw->fc.current_mode) {
@@ -1776,6 +1783,11 @@ s32 ixgbe_fc_autoneg(struct ixgbe_hw *hw)
                 /* Flow control (both Rx and Tx) is enabled by SW override. */
                 reg |= (IXGBE_PCS1GANA_SYM_PAUSE | IXGBE_PCS1GANA_ASM_PAUSE);
                 break;
+#ifdef CONFIG_DCB
+        case ixgbe_fc_pfc:
+                goto out;
+                break;
+#endif
         default:
                 hw_dbg(hw, "Flow control param set incorrectly\n");
                 ret_val = -IXGBE_ERR_CONFIG;
@@ -1874,6 +1886,13 @@ s32 ixgbe_setup_fc_generic(struct ixgbe_hw *hw, s32 packetbuf_num)
         ixgbe_link_speed speed;
         bool link_up;
 
+#ifdef CONFIG_DCB
+        if (hw->fc.requested_mode == ixgbe_fc_pfc) {
+                hw->fc.current_mode = hw->fc.requested_mode;
+                goto out;
+        }
+
+#endif
         /* Validate the packetbuf configuration */
         if (packetbuf_num < 0 || packetbuf_num > 7) {
                 hw_dbg(hw, "Invalid packet buffer number [%d], expected range "
diff --git a/drivers/net/ixgbe/ixgbe_dcb_82598.c b/drivers/net/ixgbe/ixgbe_dcb_82598.c
index df359554d492..62206273d888 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_82598.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_82598.c
@@ -298,7 +298,6 @@ s32 ixgbe_dcb_config_pfc_82598(struct ixgbe_hw *hw,
         reg = IXGBE_READ_REG(hw, IXGBE_RMCS);
         reg &= ~IXGBE_RMCS_TFCE_802_3X;
         /* correct the reporting of our flow control status */
-        hw->fc.current_mode = ixgbe_fc_none;
         reg |= IXGBE_RMCS_TFCE_PRIORITY;
         IXGBE_WRITE_REG(hw, IXGBE_RMCS, reg);
 
diff --git a/drivers/net/ixgbe/ixgbe_dcb_82599.c b/drivers/net/ixgbe/ixgbe_dcb_82599.c
index adcbac422634..470b676c1dae 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_82599.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_82599.c
@@ -299,9 +299,6 @@ s32 ixgbe_dcb_config_pfc_82599(struct ixgbe_hw *hw,
                 goto out;
         }
 
-        /* PFC is mutually exclusive with link flow control */
-        hw->fc.current_mode = ixgbe_fc_none;
-
         /* Configure PFC Tx thresholds per TC */
         for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
                 /* Config and remember Tx */
diff --git a/drivers/net/ixgbe/ixgbe_dcb_nl.c b/drivers/net/ixgbe/ixgbe_dcb_nl.c
index 8a9939ee2927..0a8731f1f237 100644
--- a/drivers/net/ixgbe/ixgbe_dcb_nl.c
+++ b/drivers/net/ixgbe/ixgbe_dcb_nl.c
@@ -130,6 +130,7 @@ static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
                 adapter->tx_ring = NULL;
                 adapter->rx_ring = NULL;
 
+                adapter->hw.fc.requested_mode = ixgbe_fc_pfc;
                 adapter->flags &= ~IXGBE_FLAG_RSS_ENABLED;
                 adapter->flags |= IXGBE_FLAG_DCB_ENABLED;
                 ixgbe_init_interrupt_scheme(adapter);
@@ -138,6 +139,7 @@ static u8 ixgbe_dcbnl_set_state(struct net_device *netdev, u8 state)
         } else {
                 /* Turn off DCB */
                 if (adapter->flags & IXGBE_FLAG_DCB_ENABLED) {
+                        adapter->hw.fc.requested_mode = ixgbe_fc_default;
                         if (netif_running(netdev))
                                 netdev->netdev_ops->ndo_stop(netdev);
                         ixgbe_reset_interrupt_capability(adapter);
diff --git a/drivers/net/ixgbe/ixgbe_type.h b/drivers/net/ixgbe/ixgbe_type.h
index 95fc36cff261..2b2ecba7b609 100644
--- a/drivers/net/ixgbe/ixgbe_type.h
+++ b/drivers/net/ixgbe/ixgbe_type.h
@@ -1939,6 +1939,9 @@ enum ixgbe_fc_mode {
         ixgbe_fc_rx_pause,
         ixgbe_fc_tx_pause,
         ixgbe_fc_full,
+#ifdef CONFIG_DCB
+        ixgbe_fc_pfc,
+#endif
         ixgbe_fc_default
 };