[PATCH v7 00/11] powerpc/powernv/cpuidle: Add support for POWER ISA v3 idle states
Michael Neuling
mikey at neuling.org
Fri Jul 8 12:49:08 AEST 2016
Except for the issue with patch 7 I've already commented on the rest of
this series is good with me. FWIW:
Acked-by: Michael Neuling <mikey at neuling.org>
Thanks.
On Fri, 2016-07-08 at 02:17 +0530, Shreyas B. Prabhu wrote:
> POWER ISA v3 defines a new idle processor core mechanism. In summary,
> a) new instruction named stop is added. This instruction replaces
> instructions like nap, sleep, rvwinkle.
> b) new per thread SPR named PSSCR is added which controls the behavior
> of stop instruction.
>
> PSSCR has following key fields
> Bits 0:3 - Power-Saving Level Status. This field indicates the
> lowest power-saving state the thread entered since stop
> instruction was last executed.
>
> Bit 42 - Enable State Loss
> 0 - No state is lost irrespective of other fields
> 1 - Allows state loss
>
> Bits 44:47 - Power-Saving Level Limit
> This limits the power-saving level that can be entered into.
>
> Bits 60:63 - Requested Level
> Used to specify which power-saving level must be entered on
> executing stop instruction
>
> Stop idle states and their properties like name, latency, target
> residency, psscr value are exposed via device tree.
>
> This patch series adds support for this new mechanism.
>
> Patches 1-6 are cleanups and code movement.
> Patch 7 adds platform specific support for stop and psscr handling.
> Patch 8 and 9 are minor cleanup in cpuidle driver.
> Patch 10 adds cpuidle driver support.
> Patch 11 makes offlined cpu use deepest stop state.
>
> Note: Documentation for the device tree bindings is posted here-
> http://patchwork.ozlabs.org/patch/629125/
>
> Changes in v7
> =============
> - File renamed to idle_book3s.S instead of idle_power_common.S
> - Comment changes
> - power_stop0, power_stop renamed to power9_idle and power_idle_stop
> - PSSCR template is now a macro instead of storing in paca
> - power9_idle in C file instead of assembly
> - Fixed TOC related bug
> - Handling subcore within FTR section
> - Functions in idle.c reordered and broken into multiple functions
> - calling __restore_cpu_power8/9 via cur_cpu_spec->cpu_restore
> - Added a minor patch with minor cleanups in cpuidle-powernv.c . This
> was mainly to make the existing code consistent with the review
> comments for new code
> - Using stack for variables while probing for idle states instead of
> kzalloc/kcalloc
>
> Changes in v6
> =============
> - Restore new POWER ISA v3 SPRS when waking up from deep idle
>
> Changes in v5
> =============
> - Use generic cpuidle constant CPUIDLE_NAME_LEN
> - Fix return code handling for of_property_read_string_array
> - Use DT flags to determine if are using stop instruction, instead of
> cpu_has_feature
> - Removed uncessary cast with names
> - &stop_loop -> stop_loop
> - Added POWERNV_THRESHOLD_LATENCY_NS to filter out idle states with high latency
>
> Changes in v4
> =============
> - Added a patch to use PNV_THREAD_WINKLE macro while requesting for winkle
> - Moved power7_powersave_common rename to more appropriate patch
> - renaming power7_enter_nap_mode to pnv_enter_arch207_idle_mode
> - Added PSSCR layout to Patch 7's commit message
> - Improved / Fixed comments
> - Fixed whitespace error in paca.h
> - Using MAX_POSSIBLE_STOP_STATE macro instead of hardcoding 0xF has
> max possible stop state
>
> Changes in v3
> =============
> - Rebased on powerpc-next
> - Dropping patch 1 since we are not adding a new file for P9 idle support
> - Improved comments in multiple places
> - Moved GET_PACA from power7_restore_hyp_resource to System Reset
> - Instead of moving few functions from idle_power7 to idle_power_common,
> renaming idle_power7.S to idle_power_common.S
> - Moved HSTATE_HWTHREAD_STATE updation to power_powersave_common
> - Dropped earlier patch 5 which moved few macros from idle_power_common to
> asm/cpuidle.h.
> - Added a patch to rename reusable power7_* idle functions to pnv_*
> - Added new patch that creates abstraction for saving SPRs before
> entering deep idle states
> - Instead of introducing new file idle_power_stop.S, P9 idle support
> is added to idle_power_common.S using CPU_FTR sections.
> - Fixed r4 reg clobbering in power_stop0
>
> Changes in v2
> =============
> - Rebased on v4.6-rc6
> - Using CPU_FTR_ARCH_300 bit instead of CPU_FTR_STOP_INST
>
> Cc: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
> Cc: Daniel Lezcano <daniel.lezcano at linaro.org>
> Cc: linux-pm at vger.kernel.org
> Cc: Benjamin Herrenschmidt <benh at au1.ibm.com>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: Paul Mackerras <paulus at ozlabs.org>
> Cc: Michael Neuling <mikey at neuling.org>
> Cc: linuxppc-dev at lists.ozlabs.org
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi at arm.com>
>
> Shreyas B. Prabhu (11):
> powerpc/powernv: Use PNV_THREAD_WINKLE macro while requesting for
> winkle
> powerpc/kvm: make hypervisor state restore a function
> powerpc/powernv: Rename idle_power7.S to idle_book3s.S
> powerpc/powernv: Rename reusable idle functions to hardware agnostic
> names
> powerpc/powernv: Make pnv_powersave_common more generic
> powerpc/powernv: abstraction for saving SPRs before entering deep idle
> states
> powerpc/powernv: Add platform support for stop instruction
> cpuidle/powernv: Use CPUIDLE_STATE_MAX instead of
> MAX_POWERNV_IDLE_STATES
> cpuidle/powernv: cleanup powernv_add_idle_states
> cpuidle/powernv: Add support for POWER ISA v3 idle states
> powerpc/powernv: Use deepest stop state when cpu is offlined
>
> arch/powerpc/include/asm/cpuidle.h | 2 +
> arch/powerpc/include/asm/kvm_book3s_asm.h | 2 +-
> arch/powerpc/include/asm/opal-api.h | 11 +-
> arch/powerpc/include/asm/ppc-opcode.h | 4 +
> arch/powerpc/include/asm/processor.h | 2 +
> arch/powerpc/include/asm/reg.h | 10 +
> arch/powerpc/kernel/Makefile | 2 +-
> arch/powerpc/kernel/exceptions-64s.S | 30 +-
> arch/powerpc/kernel/idle_book3s.S | 664 ++++++++++++++++++++++++++++++
> arch/powerpc/kernel/idle_power7.S | 515 -----------------------
> arch/powerpc/kvm/book3s_hv_rmhandlers.S | 4 +-
> arch/powerpc/platforms/powernv/idle.c | 185 +++++++--
> arch/powerpc/platforms/powernv/powernv.h | 1 +
> arch/powerpc/platforms/powernv/smp.c | 4 +-
> drivers/cpuidle/cpuidle-powernv.c | 99 ++++-
> 15 files changed, 940 insertions(+), 595 deletions(-)
> create mode 100644 arch/powerpc/kernel/idle_book3s.S
> delete mode 100644 arch/powerpc/kernel/idle_power7.S
>
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