Messages in this thread | | | From | "Gautham R. Shenoy" <> | Subject | [PATCH 0/6] Enable support for deep-stop states on POWER9 | Date | Tue, 16 May 2017 14:19:42 +0530 |
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From: "Gautham R. Shenoy" <ego@linux.vnet.ibm.com>
Hi,
This patch series contains some of the fixes required for enabling support for deep stop states such as STOP4 and STOP11 via CPU-Hotplug.
These fixes mainly ensure that some of the hypervisor resources which are lost during the deep stop state are correctly restored on a wakeup.
There are 6 patches in the series.
Patch 1 correctly initializes the core_idle_state_ptr based on the threads_per_core. core_idle_state_ptr is used to determine if a thread is the last thread entering a deep stop state or a first thread waking up from deep stop state in order to save/restore per-core resources.
Patch 2 decouples restoring timebase from restoring hypervisor resources, as there are stop states which lose hypervisor state but not the timebase.
Patch 3 saves the LPCR value before executing deep stop and restores it back to the saved value on the wakeup from stop.
Patch 4 programs the restoration of some of one-time initialized SPRs via the stop-api.
Patch 5 provides a workaround for a hardware issue on POWER9 DD1 chips where the PLS value cannot be relied upon on a wakeup from deep stop.
Patch 6 fixes the cpuidle-powernv initialization code to allow deep states that don't lose timebase.
These patches are based on the Linux upstream and have been tested with the corresponding skiboot patches in https://lists.ozlabs.org/pipermail/skiboot/2017-May/007183.html to get STOP4 working via CPU-Hotplug.
Akshay Adiga (1): powernv:idle: Restore SPRs for deep idle states via stop API.
Gautham R. Shenoy (5): powernv:idle: Correctly initialize core_idle_state_ptr powernv:idle: Decouple Timebase restore & Per-core SPRs restore powernv:idle: Restore LPCR on wakeup from deep-stop powernv:idle: Use Requested Level for restoring state on P9 DD1 cpuidle-powernv: Allow Deep stop states that don't stop time
arch/powerpc/include/asm/paca.h | 2 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kernel/idle_book3s.S | 33 +++++++--- arch/powerpc/platforms/powernv/idle.c | 112 +++++++++++++++++++++------------- drivers/cpuidle/cpuidle-powernv.c | 16 +++-- 5 files changed, 110 insertions(+), 54 deletions(-)
-- 1.8.3.1
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