[PATCH] IB: really reset QPs

When we modify a QP to the RESET state, completely clean up the QP
so that it is really and truly reset.
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/mthca/mthca_qp.c

@@ -220,6 +220,16 @@ static void *get_send_wqe(struct mthca_qp *qp, int n)
 			 (PAGE_SIZE - 1));
 }
 
+static void mthca_wq_init(struct mthca_wq *wq)
+{
+	spin_lock_init(&wq->lock);
+	wq->next_ind  = 0;
+	wq->last_comp = wq->max - 1;
+	wq->head      = 0;
+	wq->tail      = 0;
+	wq->last      = NULL;
+}
+
 void mthca_qp_event(struct mthca_dev *dev, u32 qpn,
 		    enum ib_event_type event_type)
 {
@@ -833,8 +843,8 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 		store_attrs(to_msqp(qp), attr, attr_mask);
 
 	/*
-	 * If we are moving QP0 to RTR, bring the IB link up; if we
-	 * are moving QP0 to RESET or ERROR, bring the link back down.
+	 * If we moved QP0 to RTR, bring the IB link up; if we moved
+	 * QP0 to RESET or ERROR, bring the link back down.
 	 */
 	if (is_qp0(dev, qp)) {
 		if (cur_state != IB_QPS_RTR &&
@@ -848,6 +858,26 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask)
 			mthca_CLOSE_IB(dev, to_msqp(qp)->port, &status);
 	}
 
+	/*
+	 * If we moved a kernel QP to RESET, clean up all old CQ
+	 * entries and reinitialize the QP.
+	 */
+	if (!err && new_state == IB_QPS_RESET && !qp->ibqp.uobject) {
+		mthca_cq_clean(dev, to_mcq(qp->ibqp.send_cq)->cqn, qp->qpn,
+			       qp->ibqp.srq ? to_msrq(qp->ibqp.srq) : NULL);
+		if (qp->ibqp.send_cq != qp->ibqp.recv_cq)
+			mthca_cq_clean(dev, to_mcq(qp->ibqp.recv_cq)->cqn, qp->qpn,
+				       qp->ibqp.srq ? to_msrq(qp->ibqp.srq) : NULL);
+
+		mthca_wq_init(&qp->sq);
+		mthca_wq_init(&qp->rq);
+
+		if (mthca_is_memfree(dev)) {
+			*qp->sq.db = 0;
+			*qp->rq.db = 0;
+		}
+	}
+
 	return err;
 }
 
@@ -1003,16 +1033,6 @@ static void mthca_free_memfree(struct mthca_dev *dev,
 	}
 }
 
-static void mthca_wq_init(struct mthca_wq* wq)
-{
-	spin_lock_init(&wq->lock);
-	wq->next_ind  = 0;
-	wq->last_comp = wq->max - 1;
-	wq->head      = 0;
-	wq->tail      = 0;
-	wq->last      = NULL;
-}
-
 static int mthca_alloc_qp_common(struct mthca_dev *dev,
 				 struct mthca_pd *pd,
 				 struct mthca_cq *send_cq,