IB/core: Extend create QP to get indirection table

Extend create QP to get Receive Work Queue (WQ) indirection table.

QP can be created with external Receive Work Queue indirection table,
in that case it is ready to receive immediately.
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/verbs.c

@@ -754,6 +754,12 @@ struct ib_qp *ib_create_qp(struct ib_pd *pd,
 	struct ib_qp *qp;
 	int ret;
 
+	if (qp_init_attr->rwq_ind_tbl &&
+	    (qp_init_attr->recv_cq ||
+	    qp_init_attr->srq || qp_init_attr->cap.max_recv_wr ||
+	    qp_init_attr->cap.max_recv_sge))
+		return ERR_PTR(-EINVAL);
+
 	/*
 	 * If the callers is using the RDMA API calculate the resources
 	 * needed for the RDMA READ/WRITE operations.
@@ -771,6 +777,7 @@ struct ib_qp *ib_create_qp(struct ib_pd *pd,
 	qp->real_qp    = qp;
 	qp->uobject    = NULL;
 	qp->qp_type    = qp_init_attr->qp_type;
+	qp->rwq_ind_tbl = qp_init_attr->rwq_ind_tbl;
 
 	atomic_set(&qp->usecnt, 0);
 	qp->mrs_used = 0;
@@ -788,7 +795,8 @@ struct ib_qp *ib_create_qp(struct ib_pd *pd,
 		qp->srq = NULL;
 	} else {
 		qp->recv_cq = qp_init_attr->recv_cq;
-		atomic_inc(&qp_init_attr->recv_cq->usecnt);
+		if (qp_init_attr->recv_cq)
+			atomic_inc(&qp_init_attr->recv_cq->usecnt);
 		qp->srq = qp_init_attr->srq;
 		if (qp->srq)
 			atomic_inc(&qp_init_attr->srq->usecnt);
@@ -799,7 +807,10 @@ struct ib_qp *ib_create_qp(struct ib_pd *pd,
 	qp->xrcd    = NULL;
 
 	atomic_inc(&pd->usecnt);
-	atomic_inc(&qp_init_attr->send_cq->usecnt);
+	if (qp_init_attr->send_cq)
+		atomic_inc(&qp_init_attr->send_cq->usecnt);
+	if (qp_init_attr->rwq_ind_tbl)
+		atomic_inc(&qp->rwq_ind_tbl->usecnt);
 
 	if (qp_init_attr->cap.max_rdma_ctxs) {
 		ret = rdma_rw_init_mrs(qp, qp_init_attr);
@@ -1279,6 +1290,7 @@ int ib_destroy_qp(struct ib_qp *qp)
 	struct ib_pd *pd;
 	struct ib_cq *scq, *rcq;
 	struct ib_srq *srq;
+	struct ib_rwq_ind_table *ind_tbl;
 	int ret;
 
 	WARN_ON_ONCE(qp->mrs_used > 0);
@@ -1293,6 +1305,7 @@ int ib_destroy_qp(struct ib_qp *qp)
 	scq  = qp->send_cq;
 	rcq  = qp->recv_cq;
 	srq  = qp->srq;
+	ind_tbl = qp->rwq_ind_tbl;
 
 	if (!qp->uobject)
 		rdma_rw_cleanup_mrs(qp);
@@ -1307,6 +1320,8 @@ int ib_destroy_qp(struct ib_qp *qp)
 			atomic_dec(&rcq->usecnt);
 		if (srq)
 			atomic_dec(&srq->usecnt);
+		if (ind_tbl)
+			atomic_dec(&ind_tbl->usecnt);
 	}
 
 	return ret;

include/rdma/ib_verbs.h

@@ -1017,6 +1017,7 @@ struct ib_qp_init_attr {
 	 * Only needed for special QP types, or when using the RW API.
 	 */
 	u8			port_num;
+	struct ib_rwq_ind_table *rwq_ind_tbl;
 };
 
 struct ib_qp_open_attr {
@@ -1511,6 +1512,7 @@ struct ib_qp {
 	void		       *qp_context;
 	u32			qp_num;
 	enum ib_qp_type		qp_type;
+	struct ib_rwq_ind_table *rwq_ind_tbl;
 };
 
 struct ib_mr {