[PATCH v3] powerpc/powernv: Poweroff (EPOW, DPO) events support for PowerNV platform

[Vipin K Parashar <vipin@linux.vnet.ibm.com>]

This patch adds support for FSP EPOW (Early Power Off Warning) and
DPO (Delayed Power Off) events support for PowerNV platform. EPOW events
are generated by SPCN/FSP due to various critical system conditions that
need system shutdown. Few examples of these conditions are high ambient
temperature or system running on UPS power with low UPS battery. DPO event
is generated in response to admin initiated system shutdown request.
	Upon receipt of EPOW and DPO events host kernel invokes orderly_poweroff
for performing graceful system shutdown. System admin can also add systemd
service shutdown scripts to perform any specific actions like graceful guest
shutdown upon system poweroff. libvirt-guests is systemd service available on
recent distros for management of guests at system start/shutdown time.

Changes in v3:
 - Made changes to immediately call orderly_poweroff upon receipt of
   OPAL EPOW, DPO notifications.
 - Made code changes to address review comments on previous patch.
 - Made code changes to use existing OPAL EPOW API.
 - Removed device-tree patch.

Changes in v2:
 - Made code changes to improve code as per previous review comments.
 - Added patch to obtain EPOW event timeout values from OPAL device-tree.

Vipin K Parashar (1):
  powerpc/powernv: Add poweroff (EPOW, DPO) events support for PowerNV
    platform

 arch/powerpc/include/asm/opal-api.h            |  44 +++++++
 arch/powerpc/include/asm/opal.h                |   3 +-
 arch/powerpc/platforms/powernv/opal-power.c    | 167 ++++++++++++++++++++++---
 arch/powerpc/platforms/powernv/opal-wrappers.S |   1 +
 4 files changed, 197 insertions(+), 18 deletions(-)

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1.9.3