IB/core: Add creation flags to struct ib_qp_init_attr

Add a create_flags member to struct ib_qp_init_attr that will allow a
kernel verbs consumer to create a pass special flags when creating a QP.
Add a flag value for telling low-level drivers that a QP will be used
for IPoIB UD LSO.  The create_flags member will also be useful for XRC
and ehca low-latency QP support.

Since no create_flags handling is implemented yet, add code to all
low-level drivers to return -EINVAL if create_flags is non-zero.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_qp.c

@@ -747,6 +747,11 @@ struct ib_qp *ipath_create_qp(struct ib_pd *ibpd,
 	size_t sz;
 	struct ib_qp *ret;
 
+	if (init_attr->create_flags) {
+		ret = ERR_PTR(-EINVAL);
+		goto bail;
+	}
+
 	if (init_attr->cap.max_send_sge > ib_ipath_max_sges ||
 	    init_attr->cap.max_send_wr > ib_ipath_max_qp_wrs) {
 		ret = ERR_PTR(-EINVAL);