The patch introduces global mutex for EEH so that the core data
structures can be protected by that. Also, 2 inline functions
are exported for that: eeh_lock() and eeh_unlock().
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>