RDMA/cma: Allow early transition to RTS to handle lost CM messages

During connection establishment, the passive side of a connection can
receive messages from the active side before the connection event has
been delivered to the user.  Allow the passive side to send messages
in response to received data before the event is delivered.  To handle
the case where the connection messages are lost, a new rdma_notify()
function is added that users may invoke to force a connection into the
established state.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index aa6ce47537a..6b8ec486d06 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -253,6 +253,21 @@ int rdma_listen(struct rdma_cm_id *id, int backlog);
 int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
 
 /**
+ * rdma_notify - Notifies the RDMA CM of an asynchronous event that has
+ * occurred on the connection.
+ * @id: Connection identifier to transition to established.
+ * @event: Asynchronous event.
+ *
+ * This routine should be invoked by users to notify the CM of relevant
+ * communication events.  Events that should be reported to the CM and
+ * when to report them are:
+ *
+ * IB_EVENT_COMM_EST - Used when a message is received on a connected
+ *    QP before an RTU has been received.
+ */
+int rdma_notify(struct rdma_cm_id *id, enum ib_event_type event);
+
+/**
  * rdma_reject - Called to reject a connection request or response.
  */
 int rdma_reject(struct rdma_cm_id *id, const void *private_data,