RDMA/cma: Add RDMA_CM_EVENT_TIMEWAIT_EXIT event

Consumers that want to re-use their QPs in new connections need to
know when the QP has exited the timewait state.  Report the timewait
event through the rdma_cm.
Signed-off-by: NAmir Vadai <amirv@mellanox.co.il>
Acked-by: NSean Hefty <sean.hefty@intel.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

drivers/infiniband/core/cma.c

@@ -920,7 +920,10 @@ static int cma_ib_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
 	struct rdma_cm_event event;
 	int ret = 0;
 
-	if (cma_disable_callback(id_priv, CMA_CONNECT))
+	if ((ib_event->event != IB_CM_TIMEWAIT_EXIT &&
+		cma_disable_callback(id_priv, CMA_CONNECT)) ||
+	    (ib_event->event == IB_CM_TIMEWAIT_EXIT &&
+		cma_disable_callback(id_priv, CMA_DISCONNECT)))
 		return 0;
 
 	memset(&event, 0, sizeof event);
@@ -956,6 +959,8 @@ static int cma_ib_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
 		event.event = RDMA_CM_EVENT_DISCONNECTED;
 		break;
 	case IB_CM_TIMEWAIT_EXIT:
+		event.event = RDMA_CM_EVENT_TIMEWAIT_EXIT;
+		break;
 	case IB_CM_MRA_RECEIVED:
 		/* ignore event */
 		goto out;

include/rdma/rdma_cm.h

@@ -58,7 +58,8 @@ enum rdma_cm_event_type {
 	RDMA_CM_EVENT_DEVICE_REMOVAL,
 	RDMA_CM_EVENT_MULTICAST_JOIN,
 	RDMA_CM_EVENT_MULTICAST_ERROR,
-	RDMA_CM_EVENT_ADDR_CHANGE
+	RDMA_CM_EVENT_ADDR_CHANGE,
+	RDMA_CM_EVENT_TIMEWAIT_EXIT
 };
 
 enum rdma_port_space {