sparc_bus_subregion
int (*sparc_bus_subregion)(bus_space_tag_t,
int sparc_bus_subregion(bus_space_tag_t, bus_space_tag_t, bus_space_handle_t,
.sparc_bus_subregion = sparc_bus_subregion,
_BS_PRECALL(t, sparc_bus_subregion);
ret = _BS_CALL(t, sparc_bus_subregion)(t, t0, h, o, s, hp);