RDMA/nldev: provide detailed CM_ID information

Implement RDMA nldev netlink interface to get detailed CM_ID information.

Because cm_id's are attached to rdma devices in various work queue
contexts, the pid and task information at restrak_add() time is sometimes
not useful.  For example, an nvme/f host connection cm_id ends up being
bound to a device in a work queue context and the resulting pid at attach
time no longer exists after connection setup.  So instead we mark all
cm_id's created via the rdma_ucm as "user", and all others as "kernel".
This required tweaking the restrack code a little.  It also required
wrapping some rdma_cm functions to allow passing the module name string.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

include/rdma/rdma_cm.h

@@ -157,6 +157,11 @@ struct rdma_cm_id {
 	u8			 port_num;
 };
 
+struct rdma_cm_id *__rdma_create_id(struct net *net,
+				  rdma_cm_event_handler event_handler,
+				  void *context, enum rdma_port_space ps,
+				  enum ib_qp_type qp_type, const char *caller);
+
 /**
  * rdma_create_id - Create an RDMA identifier.
  *
@@ -169,10 +174,9 @@ struct rdma_cm_id {
  *
  * The id holds a reference on the network namespace until it is destroyed.
  */
-struct rdma_cm_id *rdma_create_id(struct net *net,
-				  rdma_cm_event_handler event_handler,
-				  void *context, enum rdma_port_space ps,
-				  enum ib_qp_type qp_type);
+#define rdma_create_id(net, event_handler, context, ps, qp_type) \
+	__rdma_create_id((net), (event_handler), (context), (ps), (qp_type), \
+			 KBUILD_MODNAME)
 
 /**
   * rdma_destroy_id - Destroys an RDMA identifier.
@@ -284,6 +288,9 @@ int rdma_connect(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
  */
 int rdma_listen(struct rdma_cm_id *id, int backlog);
 
+int __rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param,
+		  const char *caller);
+
 /**
  * rdma_accept - Called to accept a connection request or response.
  * @id: Connection identifier associated with the request.
@@ -299,7 +306,8 @@ int rdma_listen(struct rdma_cm_id *id, int backlog);
  * state of the qp associated with the id is modified to error, such that any
  * previously posted receive buffers would be flushed.
  */
-int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
+#define rdma_accept(id, conn_param) \
+	__rdma_accept((id), (conn_param),  KBUILD_MODNAME)
 
 /**
  * rdma_notify - Notifies the RDMA CM of an asynchronous event that has