IB/rdmavt: Add functions to get and release QP references

This centralizes the function and improves code readability.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

include/rdma/rdmavt_qp.h

@@ -465,6 +465,25 @@ static inline struct rvt_rwqe *rvt_get_rwqe_ptr(struct rvt_rq *rq, unsigned n)
 		  rq->max_sge * sizeof(struct ib_sge)) * n);
 }
 
+/**
+ * rvt_get_qp - get a QP reference
+ * @qp - the QP to hold
+ */
+static inline void rvt_get_qp(struct rvt_qp *qp)
+{
+	atomic_inc(&qp->refcount);
+}
+
+/**
+ * rvt_put_qp - release a QP reference
+ * @qp - the QP to release
+ */
+static inline void rvt_put_qp(struct rvt_qp *qp)
+{
+	if (qp && atomic_dec_and_test(&qp->refcount))
+		wake_up(&qp->wait);
+}
+
 /**
  * rvt_qp_wqe_reserve - reserve operation
  * @qp - the rvt qp