Merge branch 'ibmvnic-Fix-reset-work-item-locking-bugs'

Thomas Falcon says:

====================
net/ibmvnic: Fix reset work item locking bugs

This patch set fixes issues with scheduling reset work items in
a tasklet context. Since ibmvnic_reset can called in an interrupt,
it should not use a mutex or allocate memory non-atomically.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 11 insertions, 9 deletions

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index ed50b8dee44f..67cc6d9c8fd7 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -1939,8 +1939,9 @@ static int do_hard_reset(struct ibmvnic_adapter *adapter,
 static struct ibmvnic_rwi *get_next_rwi(struct ibmvnic_adapter *adapter)
 {
 	struct ibmvnic_rwi *rwi;
+	unsigned long flags;
 
-	mutex_lock(&adapter->rwi_lock);
+	spin_lock_irqsave(&adapter->rwi_lock, flags);
 
 	if (!list_empty(&adapter->rwi_list)) {
 		rwi = list_first_entry(&adapter->rwi_list, struct ibmvnic_rwi,
@@ -1950,7 +1951,7 @@ static struct ibmvnic_rwi *get_next_rwi(struct ibmvnic_adapter *adapter)
 		rwi = NULL;
 	}
 
-	mutex_unlock(&adapter->rwi_lock);
+	spin_unlock_irqrestore(&adapter->rwi_lock, flags);
 	return rwi;
 }
 
@@ -2025,6 +2026,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter,
 	struct list_head *entry, *tmp_entry;
 	struct ibmvnic_rwi *rwi, *tmp;
 	struct net_device *netdev = adapter->netdev;
+	unsigned long flags;
 	int ret;
 
 	if (adapter->state == VNIC_REMOVING ||
@@ -2041,21 +2043,21 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter,
 		goto err;
 	}
 
-	mutex_lock(&adapter->rwi_lock);
+	spin_lock_irqsave(&adapter->rwi_lock, flags);
 
 	list_for_each(entry, &adapter->rwi_list) {
 		tmp = list_entry(entry, struct ibmvnic_rwi, list);
 		if (tmp->reset_reason == reason) {
 			netdev_dbg(netdev, "Skipping matching reset\n");
-			mutex_unlock(&adapter->rwi_lock);
+			spin_unlock_irqrestore(&adapter->rwi_lock, flags);
 			ret = EBUSY;
 			goto err;
 		}
 	}
 
-	rwi = kzalloc(sizeof(*rwi), GFP_KERNEL);
+	rwi = kzalloc(sizeof(*rwi), GFP_ATOMIC);
 	if (!rwi) {
-		mutex_unlock(&adapter->rwi_lock);
+		spin_unlock_irqrestore(&adapter->rwi_lock, flags);
 		ibmvnic_close(netdev);
 		ret = ENOMEM;
 		goto err;
@@ -2069,7 +2071,7 @@ static int ibmvnic_reset(struct ibmvnic_adapter *adapter,
 	}
 	rwi->reset_reason = reason;
 	list_add_tail(&rwi->list, &adapter->rwi_list);
-	mutex_unlock(&adapter->rwi_lock);
+	spin_unlock_irqrestore(&adapter->rwi_lock, flags);
 	adapter->resetting = true;
 	netdev_dbg(adapter->netdev, "Scheduling reset (reason %d)\n", reason);
 	schedule_work(&adapter->ibmvnic_reset);
@@ -4759,7 +4761,7 @@ static int ibmvnic_probe(struct vio_dev *dev, const struct vio_device_id *id)
 
 	INIT_WORK(&adapter->ibmvnic_reset, __ibmvnic_reset);
 	INIT_LIST_HEAD(&adapter->rwi_list);
-	mutex_init(&adapter->rwi_lock);
+	spin_lock_init(&adapter->rwi_lock);
 	adapter->resetting = false;
 
 	adapter->mac_change_pending = false;
diff --git a/drivers/net/ethernet/ibm/ibmvnic.h b/drivers/net/ethernet/ibm/ibmvnic.h
index 99c4f8d331ce..f2018dbebfa5 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.h
+++ b/drivers/net/ethernet/ibm/ibmvnic.h
@@ -1075,7 +1075,7 @@ struct ibmvnic_adapter {
 	struct tasklet_struct tasklet;
 	enum vnic_state state;
 	enum ibmvnic_reset_reason reset_reason;
-	struct mutex rwi_lock;
+	spinlock_t rwi_lock;
 	struct list_head rwi_list;
 	struct work_struct ibmvnic_reset;
 	bool resetting;