ixgbevf: rewrite watchdog task to function similar to igbvf

This patch cleans up the logic dealing with link down/up by breaking down the
link detection and up/down events into separate functions - similar to how these
events are handled in other drivers.

CC: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

2 files changed, 113 insertions, 75 deletions

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
index 65c2aee2a083..a41ab370278f 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf.h
@@ -436,6 +436,7 @@ struct ixgbevf_adapter {
         bool link_up;
 
         spinlock_t mbx_lock;
+        unsigned long last_reset;
 
         struct work_struct watchdog_task;
 };
diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 87f9f8686b6f..c1100654a4be 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -2231,6 +2231,8 @@ void ixgbevf_reset(struct ixgbevf_adapter *adapter)
                 memcpy(netdev->perm_addr, adapter->hw.mac.addr,
                        netdev->addr_len);
         }
+
+        adapter->last_reset = jiffies;
 }
 
 static int ixgbevf_acquire_msix_vectors(struct ixgbevf_adapter *adapter,
@@ -2684,7 +2686,8 @@ void ixgbevf_update_stats(struct ixgbevf_adapter *adapter)
         struct ixgbe_hw *hw = &adapter->hw;
         int i;
 
-        if (!adapter->link_up)
+        if (test_bit(__IXGBEVF_DOWN, &adapter->state) ||
+            test_bit(__IXGBEVF_RESETTING, &adapter->state))
                 return;
 
         UPDATE_VF_COUNTER_32bit(IXGBE_VFGPRC, adapter->stats.last_vfgprc,
@@ -2714,17 +2717,45 @@ void ixgbevf_update_stats(struct ixgbevf_adapter *adapter)
 static void ixgbevf_watchdog(unsigned long data)
 {
         struct ixgbevf_adapter *adapter = (struct ixgbevf_adapter *)data;
+
+        /* Do the reset outside of interrupt context */
+        schedule_work(&adapter->watchdog_task);
+}
+
+static void ixgbevf_reset_task(struct work_struct *work)
+{
+        struct ixgbevf_adapter *adapter;
+
+        adapter = container_of(work, struct ixgbevf_adapter, reset_task);
+
+        /* If we're already down or resetting, just bail */
+        if (test_bit(__IXGBEVF_DOWN, &adapter->state) ||
+            test_bit(__IXGBEVF_RESETTING, &adapter->state))
+                return;
+
+        adapter->tx_timeout_count++;
+
+        ixgbevf_reinit_locked(adapter);
+}
+
+/* ixgbevf_check_hang_subtask - check for hung queues and dropped interrupts
+ * @adapter - pointer to the device adapter structure
+ *
+ * This function serves two purposes.  First it strobes the interrupt lines
+ * in order to make certain interrupts are occurring.  Secondly it sets the
+ * bits needed to check for TX hangs.  As a result we should immediately
+ * determine if a hang has occurred.
+ */
+static void ixgbevf_check_hang_subtask(struct ixgbevf_adapter *adapter)
+{
         struct ixgbe_hw *hw = &adapter->hw;
         u32 eics = 0;
         int i;
 
-        /*
-         * Do the watchdog outside of interrupt context due to the lovely
-         * delays that some of the newer hardware requires
-         */
-
-        if (test_bit(__IXGBEVF_DOWN, &adapter->state))
-                goto watchdog_short_circuit;
+        /* If we're down or resetting, just bail */
+        if (test_bit(__IXGBEVF_DOWN, &adapter->state) ||
+            test_bit(__IXGBEVF_RESETTING, &adapter->state))
+                return;
 
         /* Force detection of hung controller */
         if (netif_carrier_ok(adapter->netdev)) {
@@ -2739,26 +2770,80 @@ static void ixgbevf_watchdog(unsigned long data)
                         eics |= 1 << i;
         }
 
+        /* Cause software interrupt to ensure rings are cleaned */
         IXGBE_WRITE_REG(hw, IXGBE_VTEICS, eics);
+}
 
-watchdog_short_circuit:
-        schedule_work(&adapter->watchdog_task);
+/**
+ * ixgbevf_watchdog_update_link - update the link status
+ * @adapter - pointer to the device adapter structure
+ **/
+static void ixgbevf_watchdog_update_link(struct ixgbevf_adapter *adapter)
+{
+        struct ixgbe_hw *hw = &adapter->hw;
+        u32 link_speed = adapter->link_speed;
+        bool link_up = adapter->link_up;
+        s32 err;
+
+        spin_lock_bh(&adapter->mbx_lock);
+
+        err = hw->mac.ops.check_link(hw, &link_speed, &link_up, false);
+
+        spin_unlock_bh(&adapter->mbx_lock);
+
+        /* if check for link returns error we will need to reset */
+        if (err && time_after(jiffies, adapter->last_reset + (10 * HZ))) {
+                schedule_work(&adapter->reset_task);
+                link_up = false;
+        }
+
+        adapter->link_up = link_up;
+        adapter->link_speed = link_speed;
 }
 
-static void ixgbevf_reset_task(struct work_struct *work)
+/**
+ * ixgbevf_watchdog_link_is_up - update netif_carrier status and
+ *                               print link up message
+ * @adapter - pointer to the device adapter structure
+ **/
+static void ixgbevf_watchdog_link_is_up(struct ixgbevf_adapter *adapter)
 {
-        struct ixgbevf_adapter *adapter;
-        adapter = container_of(work, struct ixgbevf_adapter, reset_task);
+        struct net_device *netdev = adapter->netdev;
 
-        /* If we're already down or resetting, just bail */
-        if (test_bit(__IXGBEVF_DOWN, &adapter->state) ||
-            test_bit(__IXGBEVF_REMOVING, &adapter->state) ||
-            test_bit(__IXGBEVF_RESETTING, &adapter->state))
+        /* only continue if link was previously down */
+        if (netif_carrier_ok(netdev))
                 return;
 
-        adapter->tx_timeout_count++;
+        dev_info(&adapter->pdev->dev, "NIC Link is Up %s\n",
+                 (adapter->link_speed == IXGBE_LINK_SPEED_10GB_FULL) ?
+                 "10 Gbps" :
+                 (adapter->link_speed == IXGBE_LINK_SPEED_1GB_FULL) ?
+                 "1 Gbps" :
+                 (adapter->link_speed == IXGBE_LINK_SPEED_100_FULL) ?
+                 "100 Mbps" :
+                 "unknown speed");
 
-        ixgbevf_reinit_locked(adapter);
+        netif_carrier_on(netdev);
+}
+
+/**
+ * ixgbevf_watchdog_link_is_down - update netif_carrier status and
+ *                                 print link down message
+ * @adapter - pointer to the adapter structure
+ **/
+static void ixgbevf_watchdog_link_is_down(struct ixgbevf_adapter *adapter)
+{
+        struct net_device *netdev = adapter->netdev;
+
+        adapter->link_speed = 0;
+
+        /* only continue if link was up previously */
+        if (!netif_carrier_ok(netdev))
+                return;
+
+        dev_info(&adapter->pdev->dev, "NIC Link is Down\n");
+
+        netif_carrier_off(netdev);
 }
 
 /**
@@ -2770,11 +2855,7 @@ static void ixgbevf_watchdog_task(struct work_struct *work)
         struct ixgbevf_adapter *adapter = container_of(work,
                                                        struct ixgbevf_adapter,
                                                        watchdog_task);
-        struct net_device *netdev = adapter->netdev;
         struct ixgbe_hw *hw = &adapter->hw;
-        u32 link_speed = adapter->link_speed;
-        bool link_up = adapter->link_up;
-        s32 need_reset;
 
         if (IXGBE_REMOVED(hw->hw_addr)) {
                 if (!test_bit(__IXGBEVF_DOWN, &adapter->state)) {
@@ -2784,66 +2865,22 @@ static void ixgbevf_watchdog_task(struct work_struct *work)
                 }
                 return;
         }
+
         ixgbevf_queue_reset_subtask(adapter);
 
         adapter->flags |= IXGBE_FLAG_IN_WATCHDOG_TASK;
 
-        /*
-         * Always check the link on the watchdog because we have
-         * no LSC interrupt
-         */
-        spin_lock_bh(&adapter->mbx_lock);
-
-        need_reset = hw->mac.ops.check_link(hw, &link_speed, &link_up, false);
-
-        spin_unlock_bh(&adapter->mbx_lock);
-
-        if (need_reset) {
-                adapter->link_up = link_up;
-                adapter->link_speed = link_speed;
-                netif_carrier_off(netdev);
-                netif_tx_stop_all_queues(netdev);
-                schedule_work(&adapter->reset_task);
-                goto pf_has_reset;
-        }
-        adapter->link_up = link_up;
-        adapter->link_speed = link_speed;
+        ixgbevf_watchdog_update_link(adapter);
 
-        if (link_up) {
-                if (!netif_carrier_ok(netdev)) {
-                        char *link_speed_string;
-                        switch (link_speed) {
-                        case IXGBE_LINK_SPEED_10GB_FULL:
-                                link_speed_string = "10 Gbps";
-                                break;
-                        case IXGBE_LINK_SPEED_1GB_FULL:
-                                link_speed_string = "1 Gbps";
-                                break;
-                        case IXGBE_LINK_SPEED_100_FULL:
-                                link_speed_string = "100 Mbps";
-                                break;
-                        default:
-                                link_speed_string = "unknown speed";
-                                break;
-                        }
-                        dev_info(&adapter->pdev->dev,
-                                "NIC Link is Up, %s\n", link_speed_string);
-                        netif_carrier_on(netdev);
-                        netif_tx_wake_all_queues(netdev);
-                }
-        } else {
-                adapter->link_up = false;
-                adapter->link_speed = 0;
-                if (netif_carrier_ok(netdev)) {
-                        dev_info(&adapter->pdev->dev, "NIC Link is Down\n");
-                        netif_carrier_off(netdev);
-                        netif_tx_stop_all_queues(netdev);
-                }
-        }
+        if (adapter->link_up)
+                ixgbevf_watchdog_link_is_up(adapter);
+        else
+                ixgbevf_watchdog_link_is_down(adapter);
 
         ixgbevf_update_stats(adapter);
 
-pf_has_reset:
+        ixgbevf_check_hang_subtask(adapter);
+
         /* Reset the timer */
         if (!test_bit(__IXGBEVF_DOWN, &adapter->state) &&
             !test_bit(__IXGBEVF_REMOVING, &adapter->state))