[PATCH rdma-next 08/10] RDMA/mana_ib: Flush and notify CQs when kernel QPs enter ERR

[Konstantin Taranov <kotaranov@linux.microsoft.com>]

From: Konstantin Taranov <kotaranov@microsoft.com>

Complete the RC software flush path by adding a kernel QP to the CQ
error lists when it transitions to the ERR state.

Invoke the CQ handlers after the transition to flush pending work
requests.

Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
---
 drivers/infiniband/hw/mana/mana_ib.h |  1 +
 drivers/infiniband/hw/mana/qp.c      | 47 ++++++++++++++++++++++++++--
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mana/mana_ib.h b/drivers/infiniband/hw/mana/mana_ib.h
index 1fc816792fc6..755fb87bfda1 100644
--- a/drivers/infiniband/hw/mana/mana_ib.h
+++ b/drivers/infiniband/hw/mana/mana_ib.h
@@ -269,6 +269,7 @@ struct mana_ib_qp {
 	bool pending_mmq_fence;
 	bool sq_sig_all;
 	enum ib_mtu mtu;
+	enum ib_qp_state state;
 
 	/* Serializes receive WR posting. */
 	spinlock_t rq_lock;
diff --git a/drivers/infiniband/hw/mana/qp.c b/drivers/infiniband/hw/mana/qp.c
index f5611fd30efe..c4992950fe17 100644
--- a/drivers/infiniband/hw/mana/qp.c
+++ b/drivers/infiniband/hw/mana/qp.c
@@ -735,6 +735,24 @@ destroy_queues:
 	return err;
 }
 
+static void mana_add_qp_to_error_cqs(struct mana_ib_qp *qp)
+{
+	struct mana_ib_cq *send_cq = container_of(qp->ibqp.send_cq, struct mana_ib_cq, ibcq);
+	struct mana_ib_cq *recv_cq = container_of(qp->ibqp.recv_cq, struct mana_ib_cq, ibcq);
+	unsigned long flags;
+
+	/* Keep ERR QPs linked until reset/destroy, including later drain WRs. */
+	spin_lock_irqsave(&send_cq->cq_lock, flags);
+	if (list_empty(&qp->send_err_node))
+		list_add_tail(&qp->send_err_node, &send_cq->send_err_qp_list);
+	spin_unlock_irqrestore(&send_cq->cq_lock, flags);
+
+	spin_lock_irqsave(&recv_cq->cq_lock, flags);
+	if (list_empty(&qp->recv_err_node))
+		list_add_tail(&qp->recv_err_node, &recv_cq->recv_err_qp_list);
+	spin_unlock_irqrestore(&recv_cq->cq_lock, flags);
+}
+
 static void mana_remove_qp_from_cqs(struct mana_ib_qp *qp, bool reset)
 {
 	struct mana_ib_cq *send_cq = container_of(qp->ibqp.send_cq, struct mana_ib_cq, ibcq);
@@ -1027,15 +1045,16 @@ static int mana_ib_gd_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 	return 0;
 }
 
-static void mana_ib_modify_qp_state(struct ib_qp *ibqp, struct ib_qp_attr *attr,
+static bool mana_ib_modify_qp_state(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 				    int attr_mask, struct ib_udata *udata)
 {
 	struct mana_ib_dev *mdev = container_of(ibqp->device, struct mana_ib_dev, ib_dev);
 	struct mana_ib_qp *qp = container_of(ibqp, struct mana_ib_qp, ibqp);
 	struct gdma_queue *rq;
+	bool notify = false;
 
 	if (udata)
-		return;
+		return false;
 
 	if (attr_mask & IB_QP_PATH_MTU)
 		qp->mtu = attr->path_mtu;
@@ -1048,6 +1067,11 @@ static void mana_ib_modify_qp_state(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		default:
 			break;
 		}
+		qp->state = attr->qp_state;
+		if (attr->qp_state == IB_QPS_ERR) {
+			mana_add_qp_to_error_cqs(qp);
+			notify = true;
+		}
 	}
 
 	if (attr_mask & IB_QP_SQ_PSN) {
@@ -1063,12 +1087,26 @@ static void mana_ib_modify_qp_state(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 						     SET_ARM_BIT, MANA_PSN_CLIENT_OFFSET);
 		}
 	}
+
+	return notify;
+}
+
+static void mana_ib_notify_error_cqs(struct mana_ib_qp *qp)
+{
+	struct ib_cq *send_cq = qp->ibqp.send_cq;
+	struct ib_cq *recv_cq = qp->ibqp.recv_cq;
+
+	if (send_cq->comp_handler)
+		send_cq->comp_handler(send_cq, send_cq->cq_context);
+	if (recv_cq != send_cq && recv_cq->comp_handler)
+		recv_cq->comp_handler(recv_cq, recv_cq->cq_context);
 }
 
 int mana_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		      int attr_mask, struct ib_udata *udata)
 {
 	struct mana_ib_qp *qp = container_of(ibqp, struct mana_ib_qp, ibqp);
+	bool notify = false;
 	int ret;
 
 	mutex_lock(&qp->modify_lock);
@@ -1086,11 +1124,14 @@ int mana_ib_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr,
 		goto out_unlock;
 	}
 
-	mana_ib_modify_qp_state(ibqp, attr, attr_mask, udata);
+	notify = mana_ib_modify_qp_state(ibqp, attr, attr_mask, udata);
 
 out_unlock:
 	mutex_unlock(&qp->modify_lock);
 
+	if (notify)
+		mana_ib_notify_error_cqs(qp);
+
 	return ret;
 }
 
-- 
2.43.0