On Tue, Oct 26, 2021 at 10:08 PM Anup Patel [off-list ref] wrote:

On Wed, Oct 27, 2021 at 5:18 AM Palmer Dabbelt [off-list ref] wrote:

quoted

On Tue, 12 Oct 2021 02:58:49 PDT (-0700), Anup Patel wrote:

quoted

This series adds RISC-V CPU Idle support using SBI HSM suspend function.

This all generally looks good to me, I'm just not sure what the spec
status is.  If one of you guys says it's frozen then that's good enough
for me, please just either point me to something where that's been
publicly said or just post here.

Atish is following up on the SBI spec process so maybe he can provide
an update on that ?

Here is the plan for SBI spec freeze process according to the newly
defined process by RVI.
https://docs.google.com/document/d/1-DZQ-5IzQlG1PLX8acic9SaLaU8SQIHRYewBrE1Zoxo/edit?usp=sharing

It's already presented to the chairs meeting and waiting for DoD
signoff. We can freeze the spec
and send it to the public review after that.

FYI: The spec version that will be frozen is tagged as 0.3.1 as we
can' travel back in time ;)

quoted

quoted

The RISC-V SBI CPU idle driver added by this series is highly inspired
from the ARM PSCI CPU idle driver.

At high-level, this series includes the following changes:
1) Preparatory arch/riscv patches (Patches 1 to 3)
2) Defines for RISC-V SBI HSM suspend (Patch 4)
3) Preparatory patch to share code between RISC-V SBI CPU idle driver
   and ARM PSCI CPU idle driver (Patch 5)
4) RISC-V SBI CPU idle driver and related DT bindings (Patches 6 to 7)

These patches can be found in riscv_sbi_hsm_suspend_v9 branch at
https://github.com/avpatel/linux

Special thanks Sandeep Tripathy for providing early feeback on SBI HSM
support in all above projects (RISC-V SBI specification, OpenSBI, and
Linux RISC-V).

Changes since v8:
 - Rebased on Linux-5.15-rc5
 - Fixed DT schema check errors in PATCH7

Changes since v7:
 - Rebased on Linux-5.15-rc3
 - Renamed cpuidle-sbi.c to cpuidle-riscv-sbi.c in PATCH6

Changes since v6:
 - Fixed error reported by "make DT_CHECKER_FLAGS=-m dt_binding_check"

Changes since v5:
 - Rebased on Linux-5.13-rc5
 - Removed unnecessary exports from PATCH5
 - Removed stray ";" from PATCH5
 - Moved sbi_cpuidle_pd_power_off() under "#ifdef CONFIG_DT_IDLE_GENPD"
   in PATCH6

Changes since v4:
 - Rebased on Linux-5.13-rc2
 - Renamed all dt_idle_genpd functions to have "dt_idle_" prefix
 - Added MAINTAINERS file entry for dt_idle_genpd

Changes since v3:
 - Rebased on Linux-5.13-rc2
 - Fixed __cpu_resume_enter() which was broken due to XIP kernel support
 - Removed "struct dt_idle_genpd_ops" abstraction which simplifies code
   sharing between ARM PSCI and RISC-V SBI drivers in PATCH5

Changes since v2:
 - Rebased on Linux-5.12-rc3
 - Updated PATCH7 to add common DT bindings for both ARM and RISC-V
   idle states
 - Added "additionalProperties = false" for both idle-states node and
   child nodes in PATCH7

Changes since v1:
 - Fixex minor typo in PATCH1
 - Use just "idle-states" as DT node name for CPU idle states
 - Added documentation for "cpu-idle-states" DT property in
   devicetree/bindings/riscv/cpus.yaml
 - Added documentation for "riscv,sbi-suspend-param" DT property in
   devicetree/bindings/riscv/idle-states.yaml

Anup Patel (8):
  RISC-V: Enable CPU_IDLE drivers
  RISC-V: Rename relocate() and make it global
  RISC-V: Add arch functions for non-retentive suspend entry/exit
  RISC-V: Add SBI HSM suspend related defines
  cpuidle: Factor-out power domain related code from PSCI domain driver
  cpuidle: Add RISC-V SBI CPU idle driver
  dt-bindings: Add common bindings for ARM and RISC-V idle states
  RISC-V: Enable RISC-V SBI CPU Idle driver for QEMU virt machine

 .../bindings/arm/msm/qcom,idle-state.txt      |   2 +-
 .../devicetree/bindings/arm/psci.yaml         |   2 +-
 .../bindings/{arm => cpu}/idle-states.yaml    | 228 ++++++-
 .../devicetree/bindings/riscv/cpus.yaml       |   6 +
 MAINTAINERS                                   |  14 +
 arch/riscv/Kconfig                            |   7 +
 arch/riscv/Kconfig.socs                       |   3 +
 arch/riscv/configs/defconfig                  |  15 +-
 arch/riscv/configs/rv32_defconfig             |   8 +-
 arch/riscv/include/asm/asm.h                  |  17 +
 arch/riscv/include/asm/cpuidle.h              |  24 +
 arch/riscv/include/asm/sbi.h                  |  27 +-
 arch/riscv/include/asm/suspend.h              |  35 +
 arch/riscv/kernel/Makefile                    |   2 +
 arch/riscv/kernel/asm-offsets.c               |   3 +
 arch/riscv/kernel/cpu_ops_sbi.c               |   2 +-
 arch/riscv/kernel/head.S                      |  18 +-
 arch/riscv/kernel/process.c                   |   3 +-
 arch/riscv/kernel/suspend.c                   |  86 +++
 arch/riscv/kernel/suspend_entry.S             | 123 ++++
 drivers/cpuidle/Kconfig                       |   9 +
 drivers/cpuidle/Kconfig.arm                   |   1 +
 drivers/cpuidle/Kconfig.riscv                 |  15 +
 drivers/cpuidle/Makefile                      |   5 +
 drivers/cpuidle/cpuidle-psci-domain.c         | 138 +---
 drivers/cpuidle/cpuidle-psci.h                |  15 +-
 drivers/cpuidle/cpuidle-riscv-sbi.c           | 626 ++++++++++++++++++
 drivers/cpuidle/dt_idle_genpd.c               | 177 +++++
 drivers/cpuidle/dt_idle_genpd.h               |  50 ++

Some of the patches that touch drivers/cpuidle don't have Acks from the
subsystem maintainers.  I'm OK taking this through the RISC-V tree, but
I'd prefer to have acks first.  I'm also fine doing something like a
shared tag between the trees, if that's better for folks.

The patches which touch the PSCI cpuidle driver have been already
reviewed by Ulf Hansson. Also, the DT bindings have been already
reviewed by Rob Herring.

I have addressed previous comments from Rafael and I was hoping
if Rafael can review it again.

Regards,
Anup

quoted

quoted

 29 files changed, 1474 insertions(+), 187 deletions(-)
 rename Documentation/devicetree/bindings/{arm => cpu}/idle-states.yaml (74%)
 create mode 100644 arch/riscv/include/asm/cpuidle.h
 create mode 100644 arch/riscv/include/asm/suspend.h
 create mode 100644 arch/riscv/kernel/suspend.c
 create mode 100644 arch/riscv/kernel/suspend_entry.S
 create mode 100644 drivers/cpuidle/Kconfig.riscv
 create mode 100644 drivers/cpuidle/cpuidle-riscv-sbi.c
 create mode 100644 drivers/cpuidle/dt_idle_genpd.c
 create mode 100644 drivers/cpuidle/dt_idle_genpd.h

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

-- 
Regards,
Atish

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel