arch/tile: enable task isolation functionality

We add the necessary call to task_isolation_start() in the
prepare_exit_to_usermode() routine.  We already unconditionally
call into this routine if TIF_NOHZ is set, since that's where
we do the user_enter() call.

We add calls to task_isolation_interrupt() in places where exceptions
may not generate signals to the application.

Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
13 files changed