net: hold netdev instance lock during ndo_open/ndo_stop

For the drivers that use shaper API, switch to the mode where
core stack holds the netdev lock. This affects two drivers:

* iavf - already grabs netdev lock in ndo_open/ndo_stop, so mostly
         remove these
* netdevsim - switch to _locked APIs to avoid deadlock

iavf_close diff is a bit confusing, the existing call looks like this:
  iavf_close() {
    netdev_lock()
    ..
    netdev_unlock()
    wait_event_timeout(down_waitqueue)
  }

I change it to the following:
  netdev_lock()
  iavf_close() {
    ..
    netdev_unlock()
    wait_event_timeout(down_waitqueue)
    netdev_lock() // reusing this lock call
  }
  netdev_unlock()

Since I'm reusing existing netdev_lock call, so it looks like I only
add netdev_unlock.

Cc: Saeed Mahameed <[email protected]>
Signed-off-by: Stanislav Fomichev <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 71f11f64b13d..9f4d223dffcf 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -4562,22 +4562,21 @@ static int iavf_open(struct net_device *netdev)
 	struct iavf_adapter *adapter = netdev_priv(netdev);
 	int err;
 
+	netdev_assert_locked(netdev);
+
 	if (adapter->flags & IAVF_FLAG_PF_COMMS_FAILED) {
 		dev_err(&adapter->pdev->dev, "Unable to open device due to PF driver failure.\n");
 		return -EIO;
 	}
 
-	netdev_lock(netdev);
 	while (!mutex_trylock(&adapter->crit_lock)) {
 		/* If we are in __IAVF_INIT_CONFIG_ADAPTER state the crit_lock
 		 * is already taken and iavf_open is called from an upper
 		 * device's notifier reacting on NETDEV_REGISTER event.
 		 * We have to leave here to avoid dead lock.
 		 */
-		if (adapter->state == __IAVF_INIT_CONFIG_ADAPTER) {
-			netdev_unlock(netdev);
+		if (adapter->state == __IAVF_INIT_CONFIG_ADAPTER)
 			return -EBUSY;
-		}
 
 		usleep_range(500, 1000);
 	}
@@ -4626,7 +4625,6 @@ static int iavf_open(struct net_device *netdev)
 	iavf_irq_enable(adapter, true);
 
 	mutex_unlock(&adapter->crit_lock);
-	netdev_unlock(netdev);
 
 	return 0;
 
@@ -4639,7 +4637,6 @@ err_setup_tx:
 	iavf_free_all_tx_resources(adapter);
 err_unlock:
 	mutex_unlock(&adapter->crit_lock);
-	netdev_unlock(netdev);
 
 	return err;
 }
@@ -4661,12 +4658,12 @@ static int iavf_close(struct net_device *netdev)
 	u64 aq_to_restore;
 	int status;
 
-	netdev_lock(netdev);
+	netdev_assert_locked(netdev);
+
 	mutex_lock(&adapter->crit_lock);
 
 	if (adapter->state <= __IAVF_DOWN_PENDING) {
 		mutex_unlock(&adapter->crit_lock);
-		netdev_unlock(netdev);
 		return 0;
 	}
 
@@ -4719,6 +4716,7 @@ static int iavf_close(struct net_device *netdev)
 	if (!status)
 		netdev_warn(netdev, "Device resources not yet released\n");
 
+	netdev_lock(netdev);
 	mutex_lock(&adapter->crit_lock);
 	adapter->aq_required |= aq_to_restore;
 	mutex_unlock(&adapter->crit_lock);