IB/IPoIB: Disable bottom half when dealing with device address

Align locking usage when touching device address with rest
of the kernel. Lock the bottom half when doing so using
netif_addr_lock_bh.

This also solves the following case as reported by lockdep:
	CPU0                    CPU1
	----                    ----
lock(_xmit_INFINIBAND);
				local_irq_disable();
				lock(&(&mc->mca_lock)->rlock);
				lock(_xmit_INFINIBAND);
<Interrupt>
lock(&(&mc->mca_lock)->rlock);

*** DEADLOCK ***

Fixes: 492a7e67ff83 ("IB/IPoIB: Allow setting the device address")
Signed-off-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 0aa52c2..248da50 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1851,7 +1851,7 @@
 	struct ipoib_dev_priv *child_priv;
 	struct net_device *netdev = priv->dev;
 
-	netif_addr_lock(netdev);
+	netif_addr_lock_bh(netdev);
 
 	memcpy(&priv->local_gid.global.interface_id,
 	       &gid->global.interface_id,
@@ -1859,7 +1859,7 @@
 	memcpy(netdev->dev_addr + 4, &priv->local_gid, sizeof(priv->local_gid));
 	clear_bit(IPOIB_FLAG_DEV_ADDR_SET, &priv->flags);
 
-	netif_addr_unlock(netdev);
+	netif_addr_unlock_bh(netdev);
 
 	if (!test_bit(IPOIB_FLAG_SUBINTERFACE, &priv->flags)) {
 		down_read(&priv->vlan_rwsem);
@@ -1875,7 +1875,7 @@
 	union ib_gid *gid = (union ib_gid *)(ss->__data + 4);
 	int ret = 0;
 
-	netif_addr_lock(dev);
+	netif_addr_lock_bh(dev);
 
 	/* Make sure the QPN, reserved and subnet prefix match the current
 	 * lladdr, it also makes sure the lladdr is unicast.
@@ -1885,7 +1885,7 @@
 	    gid->global.interface_id == 0)
 		ret = -EINVAL;
 
-	netif_addr_unlock(dev);
+	netif_addr_unlock_bh(dev);
 
 	return ret;
 }