IB/ehca: SRQ fixes to enable IPoIB CM

Fix ehca SRQ support so that IPoIB connected mode works:

 - Report max_srq > 0 if SRQ is supported
 - Report "last wqe reached" asynchronous event when base QP dies;
   this is required by the IB spec and IPoIB CM relies on receiving it
   when cleaning up.
Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ehca/ehca_hca.c

@@ -93,9 +93,13 @@ int ehca_query_device(struct ib_device *ibdev, struct ib_device_attr *props)
 	props->max_pd          = min_t(int, rblock->max_pd, INT_MAX);
 	props->max_ah          = min_t(int, rblock->max_ah, INT_MAX);
 	props->max_fmr         = min_t(int, rblock->max_mr, INT_MAX);
-	props->max_srq         = 0;
-	props->max_srq_wr      = 0;
-	props->max_srq_sge     = 0;
+
+	if (EHCA_BMASK_GET(HCA_CAP_SRQ, shca->hca_cap)) {
+		props->max_srq         = props->max_qp;
+		props->max_srq_wr      = props->max_qp_wr;
+		props->max_srq_sge     = 3;
+	}
+
 	props->max_pkeys       = 16;
 	props->local_ca_ack_delay
 		= rblock->local_ca_ack_delay;

drivers/infiniband/hw/ehca/ehca_irq.c

@@ -175,41 +175,55 @@ error_data1:
 
 }
 
-static void qp_event_callback(struct ehca_shca *shca, u64 eqe,
-			      enum ib_event_type event_type, int fatal)
+static void dispatch_qp_event(struct ehca_shca *shca, struct ehca_qp *qp,
+			      enum ib_event_type event_type)
 {
 	struct ib_event event;
-	struct ehca_qp *qp;
-	u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
-
-	read_lock(&ehca_qp_idr_lock);
-	qp = idr_find(&ehca_qp_idr, token);
-	read_unlock(&ehca_qp_idr_lock);
-
-
-	if (!qp)
-		return;
-
-	if (fatal)
-		ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
 
 	event.device = &shca->ib_device;
+	event.event = event_type;
 
 	if (qp->ext_type == EQPT_SRQ) {
 		if (!qp->ib_srq.event_handler)
 			return;
 
-		event.event = fatal ? IB_EVENT_SRQ_ERR : event_type;
 		event.element.srq = &qp->ib_srq;
 		qp->ib_srq.event_handler(&event, qp->ib_srq.srq_context);
 	} else {
 		if (!qp->ib_qp.event_handler)
 			return;
 
-		event.event = event_type;
 		event.element.qp = &qp->ib_qp;
 		qp->ib_qp.event_handler(&event, qp->ib_qp.qp_context);
 	}
+}
+
+static void qp_event_callback(struct ehca_shca *shca, u64 eqe,
+			      enum ib_event_type event_type, int fatal)
+{
+	struct ehca_qp *qp;
+	u32 token = EHCA_BMASK_GET(EQE_QP_TOKEN, eqe);
+
+	read_lock(&ehca_qp_idr_lock);
+	qp = idr_find(&ehca_qp_idr, token);
+	read_unlock(&ehca_qp_idr_lock);
+
+	if (!qp)
+		return;
+
+	if (fatal)
+		ehca_error_data(shca, qp, qp->ipz_qp_handle.handle);
+
+	dispatch_qp_event(shca, qp, fatal && qp->ext_type == EQPT_SRQ ?
+			  IB_EVENT_SRQ_ERR : event_type);
+
+	/*
+	 * eHCA only processes one WQE at a time for SRQ base QPs,
+	 * so the last WQE has been processed as soon as the QP enters
+	 * error state.
+	 */
+	if (fatal && qp->ext_type == EQPT_SRQBASE)
+		dispatch_qp_event(shca, qp, IB_EVENT_QP_LAST_WQE_REACHED);
 
 	return;
 }