e1000: convert to private mutex from rtnl

The e1000 driver when running with lockdep could run into
some possible deadlocks between the work items acquiring
rtnl and the rtnl lock being acquired before work items
were cancelled.

Use a private mutex to make sure lock ordering isn't violated.
The private mutex is only used to protect areas not generally
covered by the rtnl lock already.

(cherry picked from commit 0ef4eedc2e98edd51cd106e1f6a27178622b7e57)
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tushar Dave <tushar.n.dave@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Joe Jin <joe.jin@oracle.com>

diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h
index d8301a6a7338483b3aa917f81ce80c9bf5dac145..cf9e797b64a0e8e82f584bd15bfc98264c26dc89 100644 (file)
--- a/drivers/net/e1000/e1000.h
+++ b/drivers/net/e1000/e1000.h
@@ -308,6 +308,8 @@ struct e1000_adapter {
        struct delayed_work watchdog_task;
        struct delayed_work fifo_stall_task;
        struct delayed_work phy_info_task;
+
+       struct mutex mutex;
 };
 
 enum e1000_state_t {

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 63a94ecb830b8382eec8e7de9547ef7bcce2ff3e..5faa609740c2ae506e2fa4660688a2c8ac880c39 100644 (file)
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -546,10 +546,10 @@ static void e1000_reinit_safe(struct e1000_adapter *adapter)
 {
        while (test_and_set_bit(__E1000_RESETTING, &adapter->flags))
                msleep(1);
-       rtnl_lock();
+       mutex_lock(&adapter->mutex);
        e1000_down(adapter);
        e1000_up(adapter);
-       rtnl_unlock();
+       mutex_unlock(&adapter->mutex);
        clear_bit(__E1000_RESETTING, &adapter->flags);
 }
 
@@ -1315,6 +1315,7 @@ static int __devinit e1000_sw_init(struct e1000_adapter *adapter)
        e1000_irq_disable(adapter);
 
        spin_lock_init(&adapter->stats_lock);
+       mutex_init(&adapter->mutex);
 
        set_bit(__E1000_DOWN, &adapter->flags);
 
@@ -2329,9 +2330,11 @@ static void e1000_update_phy_info_task(struct work_struct *work)
        struct e1000_adapter *adapter = container_of(work,
                                                     struct e1000_adapter,
                                                     phy_info_task.work);
-       rtnl_lock();
+       if (test_bit(__E1000_DOWN, &adapter->flags))
+               return;
+       mutex_lock(&adapter->mutex);
        e1000_phy_get_info(&adapter->hw, &adapter->phy_info);
-       rtnl_unlock();
+       mutex_unlock(&adapter->mutex);
 }
 
 /**
@@ -2347,7 +2350,9 @@ static void e1000_82547_tx_fifo_stall_task(struct work_struct *work)
        struct net_device *netdev = adapter->netdev;
        u32 tctl;
 
-       rtnl_lock();
+       if (test_bit(__E1000_DOWN, &adapter->flags))
+               return;
+       mutex_lock(&adapter->mutex);
        if (atomic_read(&adapter->tx_fifo_stall)) {
                if ((er32(TDT) == er32(TDH)) &&
                   (er32(TDFT) == er32(TDFH)) &&
@@ -2368,7 +2373,7 @@ static void e1000_82547_tx_fifo_stall_task(struct work_struct *work)
                        schedule_delayed_work(&adapter->fifo_stall_task, 1);
                }
        }
-       rtnl_unlock();
+       mutex_unlock(&adapter->mutex);
 }
 
 bool e1000_has_link(struct e1000_adapter *adapter)
@@ -2422,6 +2427,10 @@ static void e1000_watchdog(struct work_struct *work)
        struct e1000_tx_ring *txdr = adapter->tx_ring;
        u32 link, tctl;
 
+       if (test_bit(__E1000_DOWN, &adapter->flags))
+               return;
+
+       mutex_lock(&adapter->mutex);
        link = e1000_has_link(adapter);
        if ((netif_carrier_ok(netdev)) && link)
                goto link_up;
@@ -2510,8 +2519,8 @@ link_up:
                         * (Do the reset outside of interrupt context). */
                        adapter->tx_timeout_count++;
                        schedule_work(&adapter->reset_task);
-                       /* return immediately since reset is imminent */
-                       return;
+                       /* exit immediately since reset is imminent */
+                       goto unlock;
                }
        }
 
@@ -2540,6 +2549,9 @@ link_up:
        /* Reschedule the task */
        if (!test_bit(__E1000_DOWN, &adapter->flags))
                schedule_delayed_work(&adapter->watchdog_task, 2 * HZ);
+
+unlock:
+       mutex_unlock(&adapter->mutex);
 }
 
 enum latency_range {
@@ -3238,6 +3250,8 @@ static void e1000_reset_task(struct work_struct *work)
        struct e1000_adapter *adapter =
                container_of(work, struct e1000_adapter, reset_task);
 
+       if (test_bit(__E1000_DOWN, &adapter->flags))
+               return;
        e1000_reinit_safe(adapter);
 }
 
@@ -4698,6 +4712,8 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
 
        netif_device_detach(netdev);
 
+       mutex_lock(&adapter->mutex);
+
        if (netif_running(netdev)) {
                WARN_ON(test_bit(__E1000_RESETTING, &adapter->flags));
                e1000_down(adapter);
@@ -4705,8 +4721,10 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
 
 #ifdef CONFIG_PM
        retval = pci_save_state(pdev);
-       if (retval)
+       if (retval) {
+               mutex_unlock(&adapter->mutex);
                return retval;
+       }
 #endif
 
        status = er32(STATUS);
@@ -4761,6 +4779,8 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
        if (netif_running(netdev))
                e1000_free_irq(adapter);
 
+       mutex_unlock(&adapter->mutex);
+
        pci_disable_device(pdev);
 
        return 0;