ixgbe: remove obsolete irq_sem, add driver state checking code

After testing we confirmed that the irq_sem can safely be
removed from ixgbe.

Add strict state checking code to various ethtool parts to
properly protect against races between various driver reset
paths.

Signed-off-by: Ayyappan Veeraiyan <ayyappan.veeraiyan@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/ixgbe/ixgbe.h b/drivers/net/ixgbe/ixgbe.h
index a021a6e..7dd9a03 100644 (file)
--- a/drivers/net/ixgbe/ixgbe.h
+++ b/drivers/net/ixgbe/ixgbe.h
@@ -174,7 +174,6 @@ struct ixgbe_adapter {
        struct vlan_group *vlgrp;
        u16 bd_number;
        u16 rx_buf_len;
-       atomic_t irq_sem;
        struct work_struct reset_task;
 
        /* TX */
@@ -244,6 +243,7 @@ extern const char ixgbe_driver_version[];
 
 extern int ixgbe_up(struct ixgbe_adapter *adapter);
 extern void ixgbe_down(struct ixgbe_adapter *adapter);
+extern void ixgbe_reinit_locked(struct ixgbe_adapter *adapter);
 extern void ixgbe_reset(struct ixgbe_adapter *adapter);
 extern void ixgbe_update_stats(struct ixgbe_adapter *adapter);
 extern void ixgbe_set_ethtool_ops(struct net_device *netdev);

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index 3635344..9f3cdb8 100644 (file)
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -179,12 +179,10 @@ static int ixgbe_set_pauseparam(struct net_device *netdev,
 
        hw->fc.original_type = hw->fc.type;
 
-       if (netif_running(adapter->netdev)) {
-               ixgbe_down(adapter);
-               ixgbe_up(adapter);
-       } else {
+       if (netif_running(netdev))
+               ixgbe_reinit_locked(adapter);
+       else
                ixgbe_reset(adapter);
-       }
 
        return 0;
 }
@@ -203,12 +201,10 @@ static int ixgbe_set_rx_csum(struct net_device *netdev, u32 data)
        else
                adapter->flags &= ~IXGBE_FLAG_RX_CSUM_ENABLED;
 
-       if (netif_running(netdev)) {
-               ixgbe_down(adapter);
-               ixgbe_up(adapter);
-       } else {
+       if (netif_running(netdev))
+               ixgbe_reinit_locked(adapter);
+       else
                ixgbe_reset(adapter);
-       }
 
        return 0;
 }
@@ -662,7 +658,10 @@ static int ixgbe_set_ringparam(struct net_device *netdev,
                return 0;
        }
 
-       if (netif_running(adapter->netdev))
+       while (test_and_set_bit(__IXGBE_RESETTING, &adapter->state))
+               msleep(1);
+
+       if (netif_running(netdev))
                ixgbe_down(adapter);
 
        /*
@@ -733,6 +732,7 @@ err_setup:
        if (netif_running(adapter->netdev))
                ixgbe_up(adapter);
 
+       clear_bit(__IXGBE_RESETTING, &adapter->state);
        return err;
 }
 
@@ -820,11 +820,8 @@ static int ixgbe_nway_reset(struct net_device *netdev)
 {
        struct ixgbe_adapter *adapter = netdev_priv(netdev);
 
-       if (netif_running(netdev)) {
-               ixgbe_down(adapter);
-               ixgbe_reset(adapter);
-               ixgbe_up(adapter);
-       }
+       if (netif_running(netdev))
+               ixgbe_reinit_locked(adapter);
 
        return 0;
 }

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 3732dd6..28bb203 100644 (file)
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -535,7 +535,9 @@ static irqreturn_t ixgbe_msix_lsc(int irq, void *data)
                if (!test_bit(__IXGBE_DOWN, &adapter->state))
                        mod_timer(&adapter->watchdog_timer, jiffies);
        }
-       IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMS, IXGBE_EIMS_OTHER);
+
+       if (!test_bit(__IXGBE_DOWN, &adapter->state))
+               IXGBE_WRITE_REG(hw, IXGBE_EIMS, IXGBE_EIMS_OTHER);
 
        return IRQ_HANDLED;
 }
@@ -713,7 +715,6 @@ static irqreturn_t ixgbe_intr(int irq, void *data)
        if (netif_rx_schedule_prep(netdev, &adapter->napi)) {
                /* Disable interrupts and register for poll. The flush of the
                 * posted write is intentionally left out. */
-               atomic_inc(&adapter->irq_sem);
                IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMC, ~0);
                __netif_rx_schedule(netdev, &adapter->napi);
        }
@@ -801,7 +802,6 @@ static void ixgbe_free_irq(struct ixgbe_adapter *adapter)
  **/
 static inline void ixgbe_irq_disable(struct ixgbe_adapter *adapter)
 {
-       atomic_inc(&adapter->irq_sem);
        IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMC, ~0);
        IXGBE_WRITE_FLUSH(&adapter->hw);
        synchronize_irq(adapter->pdev->irq);
@@ -813,15 +813,13 @@ static inline void ixgbe_irq_disable(struct ixgbe_adapter *adapter)
  **/
 static inline void ixgbe_irq_enable(struct ixgbe_adapter *adapter)
 {
-       if (atomic_dec_and_test(&adapter->irq_sem)) {
-               if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED)
-                       IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIAC,
-                                       (IXGBE_EIMS_ENABLE_MASK &
-                                        ~(IXGBE_EIMS_OTHER | IXGBE_EIMS_LSC)));
-               IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMS,
-                               IXGBE_EIMS_ENABLE_MASK);
-               IXGBE_WRITE_FLUSH(&adapter->hw);
-       }
+       if (adapter->flags & IXGBE_FLAG_MSIX_ENABLED)
+               IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIAC,
+                               (IXGBE_EIMS_ENABLE_MASK &
+                                ~(IXGBE_EIMS_OTHER | IXGBE_EIMS_LSC)));
+       IXGBE_WRITE_REG(&adapter->hw, IXGBE_EIMS,
+                       IXGBE_EIMS_ENABLE_MASK);
+       IXGBE_WRITE_FLUSH(&adapter->hw);
 }
 
 /**
@@ -1040,7 +1038,8 @@ static void ixgbe_vlan_rx_register(struct net_device *netdev,
        struct ixgbe_adapter *adapter = netdev_priv(netdev);
        u32 ctrl;
 
-       ixgbe_irq_disable(adapter);
+       if (!test_bit(__IXGBE_DOWN, &adapter->state))
+               ixgbe_irq_disable(adapter);
        adapter->vlgrp = grp;
 
        if (grp) {
@@ -1051,7 +1050,8 @@ static void ixgbe_vlan_rx_register(struct net_device *netdev,
                IXGBE_WRITE_REG(&adapter->hw, IXGBE_VLNCTRL, ctrl);
        }
 
-       ixgbe_irq_enable(adapter);
+       if (!test_bit(__IXGBE_DOWN, &adapter->state))
+               ixgbe_irq_enable(adapter);
 }
 
 static void ixgbe_vlan_rx_add_vid(struct net_device *netdev, u16 vid)
@@ -1066,9 +1066,13 @@ static void ixgbe_vlan_rx_kill_vid(struct net_device *netdev, u16 vid)
 {
        struct ixgbe_adapter *adapter = netdev_priv(netdev);
 
-       ixgbe_irq_disable(adapter);
+       if (!test_bit(__IXGBE_DOWN, &adapter->state))
+               ixgbe_irq_disable(adapter);
+
        vlan_group_set_device(adapter->vlgrp, vid, NULL);
-       ixgbe_irq_enable(adapter);
+
+       if (!test_bit(__IXGBE_DOWN, &adapter->state))
+               ixgbe_irq_enable(adapter);
 
        /* remove VID from filter table */
        ixgbe_set_vfta(&adapter->hw, vid, 0, false);
@@ -1224,6 +1228,16 @@ static int ixgbe_up_complete(struct ixgbe_adapter *adapter)
        return 0;
 }
 
+void ixgbe_reinit_locked(struct ixgbe_adapter *adapter)
+{
+       WARN_ON(in_interrupt());
+       while (test_and_set_bit(__IXGBE_RESETTING, &adapter->state))
+               msleep(1);
+       ixgbe_down(adapter);
+       ixgbe_up(adapter);
+       clear_bit(__IXGBE_RESETTING, &adapter->state);
+}
+
 int ixgbe_up(struct ixgbe_adapter *adapter)
 {
        /* hardware has been reset, we need to reload some things */
@@ -1408,7 +1422,6 @@ void ixgbe_down(struct ixgbe_adapter *adapter)
        msleep(10);
 
        napi_disable(&adapter->napi);
-       atomic_set(&adapter->irq_sem, 0);
 
        ixgbe_irq_disable(adapter);
 
@@ -1481,7 +1494,8 @@ static int ixgbe_clean(struct napi_struct *napi, int budget)
        /* If budget not fully consumed, exit the polling mode */
        if (work_done < budget) {
                netif_rx_complete(netdev, napi);
-               ixgbe_irq_enable(adapter);
+               if (!test_bit(__IXGBE_DOWN, &adapter->state))
+                       ixgbe_irq_enable(adapter);
        }
 
        return work_done;
@@ -1506,8 +1520,7 @@ static void ixgbe_reset_task(struct work_struct *work)
 
        adapter->tx_timeout_count++;
 
-       ixgbe_down(adapter);
-       ixgbe_up(adapter);
+       ixgbe_reinit_locked(adapter);
 }
 
 /**
@@ -1590,7 +1603,6 @@ static int __devinit ixgbe_sw_init(struct ixgbe_adapter *adapter)
                return -ENOMEM;
        }
 
-       atomic_set(&adapter->irq_sem, 1);
        set_bit(__IXGBE_DOWN, &adapter->state);
 
        return 0;
@@ -1828,10 +1840,8 @@ static int ixgbe_change_mtu(struct net_device *netdev, int new_mtu)
 
        netdev->mtu = new_mtu;
 
-       if (netif_running(netdev)) {
-               ixgbe_down(adapter);
-               ixgbe_up(adapter);
-       }
+       if (netif_running(netdev))
+               ixgbe_reinit_locked(adapter);
 
        return 0;
 }