[PATCH v5] powerpc/powernv: Poweroff (EPOW, DPO) events support for PowerNV platform

[Vipin K Parashar]

This patch adds support for FSP EPOW (Early Power Off Warning) and
DPO (Delayed Power Off) events 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 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 v5:
 - Made changes to address review comments on previous patch.

Changes in v4:
 - Made changes to address review comments on previous patch.

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 patch to extract EPOW event timeout from OPAL device-tree.

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    | 147 ++++++++++++++++++++++---
 arch/powerpc/platforms/powernv/opal-wrappers.S |   1 +
 4 files changed, 179 insertions(+), 16 deletions(-)

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1.9.3