Powernv already has support for nap and sleep and these states are used by cpuidle framework. This patchset adds support for 'deep winkle' a deeper idle state.
In deep winkle, entire chiplet (core/L2/L3) is power off, leading to higher power savings. But this results in hypervisor state loss. This patchset add the necessary infrastructure to recover from hypervisor state loss and enables offline cpus to use winkle. I've successfully tested subcore functionality with these patches. Particularly these two scenarios: Scenario 1: -> Set subcore-per-core to 4. -> Offline and online a complete core Check if core wakes up with 4 subcores Scenario 2. -> Set subcore-per-core to 1. -> Offline a core. -> set subcore-per-core to 4. -> Online a core Check if core wakes up with 4 subcores. In both these scenarios, the core wakes up with 4 subcores and can run guests on individual subcores. Note, these patches apply on top 'powernv/cpuidle: Fastsleep workaround and fixes' series. Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Srivatsa S. Bhat <sriva...@mit.edu> Cc: Preeti U. Murthy <pre...@linux.vnet.ibm.com> Cc: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org v2: Rebased on 3.17-rc7 Split from 'powerpc/powernv: Support for fastsleep and winkle' v1: https://lkml.org/lkml/2014/8/25/446 Shreyas B. Prabhu (5): powerpc/powernv: Add OPAL call to save and restore powerpc: Adding macro for accessing Thread Switch Control Register powerpc/powernv: Add winkle infrastructure powerpc/powernv: Discover and enable winkle powerpc/powernv: Enter deepest supported idle state in offline arch/powerpc/include/asm/machdep.h | 1 + arch/powerpc/include/asm/opal.h | 3 + arch/powerpc/include/asm/paca.h | 3 + arch/powerpc/include/asm/ppc-opcode.h | 2 + arch/powerpc/include/asm/processor.h | 2 + arch/powerpc/include/asm/reg.h | 1 + arch/powerpc/kernel/asm-offsets.c | 1 + arch/powerpc/kernel/exceptions-64s.S | 4 +- arch/powerpc/kernel/idle.c | 11 +++ arch/powerpc/kernel/idle_power7.S | 81 ++++++++++++++++++++- arch/powerpc/platforms/powernv/opal-wrappers.S | 1 + arch/powerpc/platforms/powernv/powernv.h | 1 + arch/powerpc/platforms/powernv/setup.c | 99 ++++++++++++++++++++++++++ arch/powerpc/platforms/powernv/smp.c | 6 +- arch/powerpc/platforms/powernv/subcore.c | 15 ++++ 15 files changed, 226 insertions(+), 5 deletions(-) -- 1.9.3 _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
