We had a deadlock between:
- free_process_memory_range (take lock) -> ihk_mc_pt_free_range ->
... -> remote_flush_tlb_array_cpumask -> "/* Wait for all cores */"
and
- obj_list_lookup() under fileobj_list_lock that disabled irqs
and thus never ack'd the remote flush
The rework is quite big but removes the need for the big lock,
although devobj and shmobj needed a new smaller lock to be
introduced - the new locks are used much more locally and
should not cause problems.
On the bright side, refcounting being moved to memobj level means
we could remove refcounting implemented separately in all object
types and simplifies code a bit.
Change-Id: I6bc8438a98b1d8edddc91c4ac33c11b88e097ebb