Notwithstanding any law to the contrary, including §4-4-121, §39-17-1551, or title 39, chapter 17, part 18, the board of regents, the trustees of the university of Tennessee, and state university board of each public institution of higher education may adopt policies regulating smoking on property owned or operated by the institution; provided, that such policies do not permit smoking in any location where smoking is otherwise prohibited by law. Such policies may prohibit smoking in all indoor and outdoor areas of property owned or operated by the institution. The board of regents, the trustees of the university of Tennessee, and state university board of each institution is encouraged to prohibit smoking in all enclosed spaces and provide for reasonable smoke-free zones at all facility entrances and exits.