Re: [PATCH 00/14] Introduce PECI subsystem

["Winiarska, Iwona" <iwona.winiarska@intel.com>]

On Wed, 2021-07-14 at 16:51 +0000, Williams, Dan J wrote:
> On Tue, 2021-07-13 at 00:04 +0200, Iwona Winiarska wrote:
> > Note: All changes to arch/x86 are contained within patches 01-02.
> 
> Hi Iwona,
> 
> One meta question first, who is this submission "To:"? Is there an
> existing upstream maintainer path for OpenBMC changes? Are you
> expecting contributions to this subsystem from others? While Greg
> sometimes ends up as default maintainer for new stuff, I wonder if
> someone from the OpenBMC commnuity should step up to fill this role?
> 

The intention was to direct it to Greg, but I guess I didn't express
that through the mail headers.
I am expecting contributions - for example there is at least one other
major BMC vendor which also ships PECI controllers.

From my perspective, the pieces that make up a BMC are pretty loosely
connected (at least from the kernel perspective - scattered all over
the kernel tree), so I don't see how that would work in practice.

Thanks
-Iwona


> > 
> > The Platform Environment Control Interface (PECI) is a communication
> > interface between Intel processors and management controllers (e.g.
> > Baseboard Management Controller, BMC).
> > 
> > This series adds a PECI subsystem and introduces drivers which run in
> > the Linux instance on the management controller (not the main Intel
> > processor) and is intended to be used by the OpenBMC [1], a Linux
> > distribution for BMC devices.
> > The information exposed over PECI (like processor and DIMM
> > temperature) refers to the Intel processor and can be consumed by
> > daemons running on the BMC to, for example, display the processor
> > temperature in its web interface.
> > 
> > The PECI bus is collection of code that provides interface support
> > between PECI devices (that actually represent processors) and PECI
> > controllers (such as the "peci-aspeed" controller) that allow to
> > access physical PECI interface. PECI devices are bound to PECI
> > drivers that provides access to PECI services. This series introduces
> > a generic "peci-cpu" driver that exposes hardware monitoring
> > "cputemp"
> > and "dimmtemp" using the auxiliary bus.
> > 
> > Exposing "raw" PECI to userspace, either to write userspace drivers
> > or
> > for debug/testing purpose was left out of this series to encourage
> > writing kernel drivers instead, but may be pursued in the future.
> > 
> > Introducing PECI to upstream Linux was already attempted before [2].
> > Since it's been over a year since last revision, and the series
> > changed quite a bit in the meantime, I've decided to start from v1.
> > 
> > I would also like to give credit to everyone who helped me with
> > different aspects of preliminary review:
> > - Pierre-Louis Bossart,
> > - Tony Luck, 
> > - Andy Shevchenko,
> > - Dave Hansen.
> > 
> > [1] https://github.com/openbmc/openbmc
> > [2] 
> > https://lore.kernel.org/openbmc/20191211194624.2872-1-jae.hyun.yoo@linux.intel.com/
> > 
> > Iwona Winiarska (12):
> >   x86/cpu: Move intel-family to arch-independent headers
> >   x86/cpu: Extract cpuid helpers to arch-independent
> >   dt-bindings: Add generic bindings for PECI
> >   dt-bindings: Add bindings for peci-aspeed
> >   ARM: dts: aspeed: Add PECI controller nodes
> >   peci: Add core infrastructure
> >   peci: Add device detection
> >   peci: Add support for PECI device drivers
> >   peci: Add peci-cpu driver
> >   hwmon: peci: Add cputemp driver
> >   hwmon: peci: Add dimmtemp driver
> >   docs: Add PECI documentation
> > 
> > Jae Hyun Yoo (2):
> >   peci: Add peci-aspeed controller driver
> >   docs: hwmon: Document PECI drivers
> > 
> >  .../devicetree/bindings/peci/peci-aspeed.yaml | 111 ++++
> >  .../bindings/peci/peci-controller.yaml        |  28 +
> >  Documentation/hwmon/index.rst                 |   2 +
> >  Documentation/hwmon/peci-cputemp.rst          |  93 ++++
> >  Documentation/hwmon/peci-dimmtemp.rst         |  58 ++
> >  Documentation/index.rst                       |   1 +
> >  Documentation/peci/index.rst                  |  16 +
> >  Documentation/peci/peci.rst                   |  48 ++
> >  MAINTAINERS                                   |  32 ++
> >  arch/arm/boot/dts/aspeed-g4.dtsi              |  14 +
> >  arch/arm/boot/dts/aspeed-g5.dtsi              |  14 +
> >  arch/arm/boot/dts/aspeed-g6.dtsi              |  14 +
> >  arch/x86/Kconfig                              |   1 +
> >  arch/x86/include/asm/cpu.h                    |   3 -
> >  arch/x86/include/asm/intel-family.h           | 141 +----
> >  arch/x86/include/asm/microcode.h              |   2 +-
> >  arch/x86/kvm/cpuid.h                          |   3 +-
> >  arch/x86/lib/Makefile                         |   2 +-
> >  drivers/Kconfig                               |   3 +
> >  drivers/Makefile                              |   1 +
> >  drivers/edac/mce_amd.c                        |   3 +-
> >  drivers/hwmon/Kconfig                         |   2 +
> >  drivers/hwmon/Makefile                        |   1 +
> >  drivers/hwmon/peci/Kconfig                    |  31 ++
> >  drivers/hwmon/peci/Makefile                   |   7 +
> >  drivers/hwmon/peci/common.h                   |  46 ++
> >  drivers/hwmon/peci/cputemp.c                  | 503
> > +++++++++++++++++
> >  drivers/hwmon/peci/dimmtemp.c                 | 508
> > ++++++++++++++++++
> >  drivers/peci/Kconfig                          |  36 ++
> >  drivers/peci/Makefile                         |  10 +
> >  drivers/peci/controller/Kconfig               |  12 +
> >  drivers/peci/controller/Makefile              |   3 +
> >  drivers/peci/controller/peci-aspeed.c         | 501
> > +++++++++++++++++
> >  drivers/peci/core.c                           | 224 ++++++++
> >  drivers/peci/cpu.c                            | 347 ++++++++++++
> >  drivers/peci/device.c                         | 211 ++++++++
> >  drivers/peci/internal.h                       | 137 +++++
> >  drivers/peci/request.c                        | 502
> > +++++++++++++++++
> >  drivers/peci/sysfs.c                          |  82 +++
> >  include/linux/peci-cpu.h                      |  38 ++
> >  include/linux/peci.h                          |  93 ++++
> >  include/linux/x86/cpu.h                       |   9 +
> >  include/linux/x86/intel-family.h              | 146 +++++
> >  lib/Kconfig                                   |   5 +
> >  lib/Makefile                                  |   2 +
> >  lib/x86/Makefile                              |   3 +
> >  {arch/x86/lib => lib/x86}/cpu.c               |   2 +-
> >  47 files changed, 3902 insertions(+), 149 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/peci/peci-
> > aspeed.yaml
> >  create mode 100644 Documentation/devicetree/bindings/peci/peci-
> > controller.yaml
> >  create mode 100644 Documentation/hwmon/peci-cputemp.rst
> >  create mode 100644 Documentation/hwmon/peci-dimmtemp.rst
> >  create mode 100644 Documentation/peci/index.rst
> >  create mode 100644 Documentation/peci/peci.rst
> >  create mode 100644 drivers/hwmon/peci/Kconfig
> >  create mode 100644 drivers/hwmon/peci/Makefile
> >  create mode 100644 drivers/hwmon/peci/common.h
> >  create mode 100644 drivers/hwmon/peci/cputemp.c
> >  create mode 100644 drivers/hwmon/peci/dimmtemp.c
> >  create mode 100644 drivers/peci/Kconfig
> >  create mode 100644 drivers/peci/Makefile
> >  create mode 100644 drivers/peci/controller/Kconfig
> >  create mode 100644 drivers/peci/controller/Makefile
> >  create mode 100644 drivers/peci/controller/peci-aspeed.c
> >  create mode 100644 drivers/peci/core.c
> >  create mode 100644 drivers/peci/cpu.c
> >  create mode 100644 drivers/peci/device.c
> >  create mode 100644 drivers/peci/internal.h
> >  create mode 100644 drivers/peci/request.c
> >  create mode 100644 drivers/peci/sysfs.c
> >  create mode 100644 include/linux/peci-cpu.h
> >  create mode 100644 include/linux/peci.h
> >  create mode 100644 include/linux/x86/cpu.h
> >  create mode 100644 include/linux/x86/intel-family.h
> >  create mode 100644 lib/x86/Makefile
> >  rename {arch/x86/lib => lib/x86}/cpu.c (95%)
> > 
>