thunderbolt: Expose make_header() to other files

We will be using this function in files introduced in subsequent
patches. While there the function is renamed to tb_cfg_make_header()
following tb_cfg_get_route().

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/thunderbolt/ctl.h b/drivers/thunderbolt/ctl.h
index 9812b1c..914da86 100644
--- a/drivers/thunderbolt/ctl.h
+++ b/drivers/thunderbolt/ctl.h
@@ -43,6 +43,17 @@
 	return (u64) header->route_hi << 32 | header->route_lo;
 }
 
+static inline struct tb_cfg_header tb_cfg_make_header(u64 route)
+{
+	struct tb_cfg_header header = {
+		.route_hi = route >> 32,
+		.route_lo = route,
+	};
+	/* check for overflow, route_hi is not 32 bits! */
+	WARN_ON(tb_cfg_get_route(&header) != route);
+	return header;
+}
+
 int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port,
 		 enum tb_cfg_error error);
 struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route,