12-eeh-event-dispatcher.patch

ppc64: EEH Recovery dispatcher thread

This patch adds a mechanism to create recovery threads when an
EEH event is received.  Since an EEH freeze state may be detected
within an interrupt context, we need to get out of the interrupt
context before starting recovery. This dispatcher does this in
two steps: first, it uses a workqueue to get out, and then
lanuches a kernel thread, so that the recovery routine can
sleep for exteded periods without upseting the keventd.

A kernel thread is created with each EEH event, rather than
having one long-running daemon started at boot time.  This is
because it is anticipated that EEH events will be very rare
(very very rare, ideally) and so its pointless to cluter the
process tables with a daemon that will almost never run.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>