IB/rdmavt: Move driver helper functions to a common structure

Drivers are going to need to provide multiple functions for rdmavt to
call in to. We already have one, so go ahead and push this into a
data structure designated for driver supplied functions.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/sw/rdmavt/vt.c

@@ -280,8 +280,12 @@ int rvt_register_device(struct rvt_dev_info *rdi)
 	spin_lock_init(&rdi->n_pds_lock);
 	rdi->n_pds_allocated = 0;
 
+	/* Validate that drivers have provided the right functions */
+	if (!rdi->driver_f.port_callback)
+		return -EINVAL;
+
 	/* We are now good to announce we exist */
-	return ib_register_device(&rdi->ibdev, rdi->port_callback);
+	return ib_register_device(&rdi->ibdev, rdi->driver_f.port_callback);
 }
 EXPORT_SYMBOL(rvt_register_device);