[RFC,V3,0/4] arm_scmi: vendors: ARM SCMI Qualcomm Vendor Protocol

Message

Sibi Sankar July 2, 2024, 7:14 p.m. UTC

The SCMI QCOM vendor protocol provides a generic way of exposing a
number of Qualcomm SoC specific features (like memory bus scaling)
through a mixture of pre-determined algorithm strings and param_id
pairs hosted on the SCMI controller. Introduce a client driver that
uses the memlat algorithm string hosted on QCOM SCMI Vendor Protocol
to detect memory latency workloads and control frequency/level of
the various memory buses (DDR/LLCC/DDR_QOS).

Generic QCOM Vendor protocol background:
It was found that a lot of the vendor protocol used internally was
for debug/internal development purposes that would either be super
SoC specific or had to be disabled because of some features being
fused out during production. This lead to a large number of vendor
protocol numbers being quickly consumed and were never released
either. Using a generic vendor protocol with functionality abstracted
behind algorithm strings gave us the flexibility of allowing such
functionality exist during initial development/debugging while
still being able to expose functionality like memlat once they have
matured enough. The param-ids are certainly expected to act as ABI
for algorithms strings like MEMLAT.

Thanks in advance for taking time to review the series.

Opens:
* opp-tables are used but they don't get to be added to the scmi device (thus we
  rely on a lot of manual parsing) because the memlat client driver doesn't vote
  on these resources clocks/interconnects/power-domain from the kernel and some
  of the resources aren't modeled in the first place like DDR_QOS.

To Dos:
* More documentation [Sudeep/Dmitry/Konrad]
* Use alternate bindings instead of freq-table-Hz. [Dmitry]
* Prevent duplication of code using vendor protocol driver. [Dmitry]

V2:
* Drop container dvfs memlat container node. [Rob]
* Move scmi-memlat.yaml to protocol level given that a lot of vendors might end up
  using the same protocol number. [Rob]
* Replace qcom,cpulist with the standard "cpus" property. [Rob]
* Fix up compute-type/ipm-ceil required. [Rob]
* Make driver changes to the accommodate bindings changes. [Rob]
* Minor fixups in subjects/coverletter.
* Minor style fixes in dts.

V1:
* Add missing bindings for the protocol. [Konrad/Dmitry]
* Use alternate bindings. [Dmitry/Konrad]
* Rebase on top of Cristian's "SCMI multiple vendor protocol support" series. [Cristian]
* Add more documentation wherever possible. [Sudeep]
* Replace pr_err/info with it's dev equivalents.
* Mixed tabs and initialization cleanups in the memlat driver. [Konrad]
* Commit message update for the memlat driver. [Dmitry]
* Cleanups/Fixes suggested for the client driver. [Dmitry/Konrad/Cristian]
* Use opp-tables instead of memfreq-tbl. [Dmitry/Konrad]
* Detect physical cpu to deal with variants with reduced cpu count.
* Add support for DDR_QOS mem_type.

Sibi Sankar (4):
  dt-bindings: firmware: Document bindings for ARM SCMI QCOM Vendor
    Protocol
  firmware: arm_scmi: vendors: Add ARM SCMI QCOM vendor protocol v1.0
  soc: qcom: Introduce SCMI based Memlat (Memory Latency) governor
  arm64: dts: qcom: x1e80100: Enable LLCC/DDR/DDR_QOS dvfs

 .../bindings/firmware/arm,scmi.yaml           |  15 +
 .../bindings/soc/qcom/qcom,scmi-memlat.yaml   | 242 ++++++++
 arch/arm64/boot/dts/qcom/x1e80100.dtsi        | 138 +++++
 drivers/firmware/arm_scmi/vendors/Kconfig     |  12 +
 drivers/firmware/arm_scmi/vendors/Makefile    |   2 +-
 .../arm_scmi/vendors/qcom_scmi_vendor.c       | 184 ++++++
 drivers/soc/qcom/Kconfig                      |  12 +
 drivers/soc/qcom/Makefile                     |   1 +
 drivers/soc/qcom/qcom_scmi_client.c           | 583 ++++++++++++++++++
 include/dt-bindings/soc/qcom,scmi-vendor.h    |  22 +
 include/linux/qcom_scmi_vendor.h              |  39 ++
 11 files changed, 1249 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/soc/qcom/qcom,scmi-memlat.yaml
 create mode 100644 drivers/firmware/arm_scmi/vendors/qcom_scmi_vendor.c
 create mode 100644 drivers/soc/qcom/qcom_scmi_client.c
 create mode 100644 include/dt-bindings/soc/qcom,scmi-vendor.h
 create mode 100644 include/linux/qcom_scmi_vendor.h