[infiniband] Record multicast GID attachment as part of group membership

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/ipoib.c

 	struct ipoib_mac mac;
 	/** Broadcast MAC */
 	struct ipoib_mac broadcast;
-	/** Joined to IPv4 broadcast multicast group
-	 *
-	 * This flag indicates whether or not we have initiated the
-	 * join to the IPv4 broadcast multicast group.
-	 */
-	int broadcast_joined;
 	/** IPv4 broadcast multicast group membership */
-	struct ib_mc_membership broadcast_membership;
+	struct ib_mc_membership membership;
 	/** REMAC cache */
 	struct list_head peers;
 };
 			   struct ib_queue_pair *qp __unused,
 			   struct ib_mc_membership *membership, int rc,
 			   union ib_mad *mad __unused ) {
-	struct ipoib_device *ipoib = container_of ( membership,
-				   struct ipoib_device, broadcast_membership );
+	struct ipoib_device *ipoib =
+		container_of ( membership, struct ipoib_device, membership );
 
 	/* Record join status as link status */
 	netdev_link_err ( ipoib->netdev, rc );
 	int rc;
 
 	if ( ( rc = ib_mcast_join ( ipoib->ibdev, ipoib->qp,
-				    &ipoib->broadcast_membership,
-				    &ipoib->broadcast.gid,
+				    &ipoib->membership, &ipoib->broadcast.gid,
 				    ipoib_join_complete ) ) != 0 ) {
 		DBGC ( ipoib, "IPoIB %p could not join broadcast group: %s\n",
 		       ipoib, strerror ( rc ) );
 		return rc;
 	}
-	ipoib->broadcast_joined = 1;
 
 	return 0;
 }
  */
 static void ipoib_leave_broadcast_group ( struct ipoib_device *ipoib ) {
 
-	if ( ipoib->broadcast_joined ) {
-		ib_mcast_leave ( ipoib->ibdev, ipoib->qp,
-				 &ipoib->broadcast_membership );
-		ipoib->broadcast_joined = 0;
-	}
+	ib_mcast_leave ( ipoib->ibdev, ipoib->qp, &ipoib->membership );
 }
 
 /**

src/include/ipxe/ib_mcast.h

 	struct ib_queue_pair *qp;
 	/** Multicast GID */
 	union ib_gid gid;
+	/** Attached to multicast GID */
+	int attached;
 	/** Multicast group join transaction */
 	struct ib_mad_transaction *madx;
 	/** Handle join success/failure

src/net/infiniband/ib_mcast.c

 	DBGC ( ibdev, "IBDEV %s QPN %#lx joining " IB_GID_FMT "\n",
 	       ibdev->name, qp->qpn, IB_GID_ARGS ( gid ) );
 
-	/* Sanity check */
+	/* Sanity checks */
 	assert ( qp != NULL );
+	assert ( ! membership->attached );
 
 	/* Initialise structure */
 	membership->qp = qp;
 		       ibdev->name, qp->qpn, strerror ( rc ) );
 		goto err_mcast_attach;
 	}
+	membership->attached = 1;
 
 	/* Initiate multicast membership join */
 	ib_mcast_mad ( ibdev, gid, 1, &mad );
 	ib_destroy_madx ( ibdev, ibdev->gsi, membership->madx );
  err_create_madx:
 	ib_mcast_detach ( ibdev, qp, gid );
+	membership->attached = 0;
  err_mcast_attach:
 	return rc;
 }
 	union ib_mad mad;
 	int rc;
 
+	/* Do nothing if we are already detached from the multicast GID */
+	if ( ! membership->attached )
+		return;
+
 	DBGC ( ibdev, "IBDEV %s QPN %#lx leaving " IB_GID_FMT "\n",
 	       ibdev->name, qp->qpn, IB_GID_ARGS ( gid ) );
 
 
 	/* Detach from multicast GID */
 	ib_mcast_detach ( ibdev, qp, &membership->gid );
+	membership->attached = 0;
 
 	/* Cancel multicast membership join, if applicable */
 	if ( membership->madx ) {