[PATCH v2 0/4] powernv: cpuidle: Redesign idle states management

[Shreyas B. Prabhu]

Deep idle states like sleep and winkle are per core idle states. A core
enters these states only when all the threads enter either the particular
idle state or a deeper one. There are tasks like fastsleep hardware bug
workaround and hypervisor core state save which have to be done only by
the last thread of the core entering deep idle state and similarly tasks
like timebase resync, hypervisor core register restore that have to be
done only by the first thread waking up from these states. 

The current idle state management does not have a way to distinguish the
first/last thread of the core waking/entering idle states. Tasks like
timebase resync are done for all the threads. This is not only is suboptimal,
but can cause functionality issues when subcores are involved.

Winkle is deeper idle state compared to fastsleep. In this state the power
supply to the chiplet, i.e core, private L2 and private L3 is turned off.
This results in a total hypervisor state loss. This patch set adds support
for winkle and provides a way to track the idle states of the threads of the
core and use it for idle state management of idle states sleep and winkle.


Changes in v2:
--------------
-Using PNV_THREAD_NAP/SLEEP defines while calling power7_powersave_common
-Comment changes based on review
-Rebased on top of 3.18-rc6


Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: Vaidyanathan Srinivasan <svaidy@xxxxxxxxxxxxxxxxxx>
Cc: Preeti U Murthy <preeti@xxxxxxxxxxxxxxxxxx>

Paul Mackerras (1):
  powerpc: powernv: Switch off MMU before entering nap/sleep/rvwinkle
    mode

Preeti U. Murthy (1):
  powerpc/powernv: Enable Offline CPUs to enter deep idle states

Shreyas B. Prabhu (2):
  powernv: cpuidle: Redesign idle states management
  powernv: powerpc: Add winkle support for offline cpus

 arch/powerpc/include/asm/cpuidle.h             |  14 ++
 arch/powerpc/include/asm/opal.h                |  13 +
 arch/powerpc/include/asm/paca.h                |   6 +
 arch/powerpc/include/asm/ppc-opcode.h          |   2 +
 arch/powerpc/include/asm/processor.h           |   1 +
 arch/powerpc/include/asm/reg.h                 |   4 +
 arch/powerpc/kernel/asm-offsets.c              |   6 +
 arch/powerpc/kernel/cpu_setup_power.S          |   4 +
 arch/powerpc/kernel/exceptions-64s.S           |  30 ++-
 arch/powerpc/kernel/idle_power7.S              | 332 +++++++++++++++++++++----
 arch/powerpc/platforms/powernv/opal-wrappers.S |  39 +++
 arch/powerpc/platforms/powernv/powernv.h       |   2 +
 arch/powerpc/platforms/powernv/setup.c         | 160 ++++++++++++
 arch/powerpc/platforms/powernv/smp.c           |  10 +-
 arch/powerpc/platforms/powernv/subcore.c       |  34 +++
 arch/powerpc/platforms/powernv/subcore.h       |   1 +
 drivers/cpuidle/cpuidle-powernv.c              |  10 +-
 17 files changed, 608 insertions(+), 60 deletions(-)
 create mode 100644 arch/powerpc/include/asm/cpuidle.h

-- 
1.9.3

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