RDMA/bnxt_re: Flush CQ notification Work Queue before destroying QP

Destroy_qp shall wait for any outstanding CQ notification to be
flushed out before proceeding with QP destroy. Flushing the WQ
before destroying the QP.
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/bnxt_re/ib_verbs.c

@@ -785,6 +785,7 @@ int bnxt_re_destroy_qp(struct ib_qp *ib_qp)
 	struct bnxt_re_dev *rdev = qp->rdev;
 	int rc;
 
+	bnxt_qplib_flush_cqn_wq(&qp->qplib_qp);
 	bnxt_qplib_del_flush_qp(&qp->qplib_qp);
 	rc = bnxt_qplib_destroy_qp(&rdev->qplib_res, &qp->qplib_qp);
 	if (rc) {

drivers/infiniband/hw/bnxt_re/qplib_fp.c

@@ -2537,3 +2537,10 @@ void bnxt_qplib_req_notify_cq(struct bnxt_qplib_cq *cq, u32 arm_type)
 	atomic_set(&cq->arm_state, 1);
 	spin_unlock_irqrestore(&cq->hwq.lock, flags);
 }
+
+void bnxt_qplib_flush_cqn_wq(struct bnxt_qplib_qp *qp)
+{
+	flush_workqueue(qp->scq->nq->cqn_wq);
+	if (qp->scq != qp->rcq)
+		flush_workqueue(qp->rcq->nq->cqn_wq);
+}

drivers/infiniband/hw/bnxt_re/qplib_fp.h

@@ -478,4 +478,5 @@ void bnxt_qplib_release_cq_locks(struct bnxt_qplib_qp *qp,
 int bnxt_qplib_process_flush_list(struct bnxt_qplib_cq *cq,
 				  struct bnxt_qplib_cqe *cqe,
 				  int num_cqes);
+void bnxt_qplib_flush_cqn_wq(struct bnxt_qplib_qp *qp);
 #endif /* __BNXT_QPLIB_FP_H__ */