rdma_cm: add rdma_reject_msg() helper function

rdma_reject_msg() returns a pointer to a string message associated with
the transport reject reason codes.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/include/rdma/ib_cm.h b/include/rdma/ib_cm.h
index 92a7d85..b49258b 100644
--- a/include/rdma/ib_cm.h
+++ b/include/rdma/ib_cm.h
@@ -603,4 +603,10 @@
 int ib_send_cm_sidr_rep(struct ib_cm_id *cm_id,
 			struct ib_cm_sidr_rep_param *param);
 
+/**
+ * ibcm_reject_msg - return a pointer to a reject message string.
+ * @reason: Value returned in the REJECT event status field.
+ */
+const char *__attribute_const__ ibcm_reject_msg(int reason);
+
 #endif /* IB_CM_H */
diff --git a/include/rdma/iw_cm.h b/include/rdma/iw_cm.h
index 6d0065c..5cd7701 100644
--- a/include/rdma/iw_cm.h
+++ b/include/rdma/iw_cm.h
@@ -253,4 +253,10 @@
 int iw_cm_init_qp_attr(struct iw_cm_id *cm_id, struct ib_qp_attr *qp_attr,
 		       int *qp_attr_mask);
 
+/**
+ * iwcm_reject_msg - return a pointer to a reject message string.
+ * @reason: Value returned in the REJECT event status field.
+ */
+const char *__attribute_const__ iwcm_reject_msg(int reason);
+
 #endif /* IW_CM_H */
diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index 81fb1d1..f11a768 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -388,4 +388,12 @@
  */
 __be64 rdma_get_service_id(struct rdma_cm_id *id, struct sockaddr *addr);
 
+/**
+ * rdma_reject_msg - return a pointer to a reject message string.
+ * @id: Communication identifier that received the REJECT event.
+ * @reason: Value returned in the REJECT event status field.
+ */
+const char *__attribute_const__ rdma_reject_msg(struct rdma_cm_id *id,
+						int reason);
+
 #endif /* RDMA_CM_H */