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[v4,0/6] Introduce LMh driver for Qualcomm SoCs

Message ID 20210727152512.1098329-1-thara.gopinath@linaro.org (mailing list archive)
Headers show
Series Introduce LMh driver for Qualcomm SoCs | expand

Message

Thara Gopinath July 27, 2021, 3:25 p.m. UTC
Limits Management Hardware(LMh) is a hardware infrastructure on some
Qualcomm SoCs that can enforce temperature and current limits as programmed
by software for certain IPs like CPU. On many newer SoCs LMh is configured
by firmware/TZ and no programming is needed from the kernel side. But on
certain SoCs like sdm845 the firmware does not do a complete programming of
the h/w block. On such SoCs kernel software has to explicitly set up the
temperature limits and turn on various monitoring and enforcing algorithms
on the hardware.

Introduce support for enabling and programming various limit settings and
monitoring capabilities of Limits Management Hardware(LMh) associated with
cpu clusters. Also introduce support in cpufreq hardware driver to monitor
the interrupt associated with cpu frequency throttling so that this
information can be conveyed to the schdeuler via thermal pressure
interface.

With this patch series following cpu performance improvement(30-70%) is
observed on sdm845. The reasoning here is that without LMh being programmed
properly from the kernel, the default settings were enabling thermal
mitigation for CPUs at too low a temperature (around 70-75 degree C).  This
in turn meant that many a time CPUs were never actually allowed to hit the
maximum possible/required frequencies.

UnixBench whets and dhry (./Run whets dhry)
System Benchmarks Index Score

                Without LMh Support             With LMh Support
1 copy test     1353.7                          1773.2

8 copy tests    4473.6                          7402.3

Sysbench cpu
sysbench cpu --threads=8 --time=60 --cpu-max-prime=100000 run

                Without LMh Support             With LMh Support
Events per
second                  355                             614

Avg Latency(ms)         21.84                           13.02

v3->v4:
	- Rebased to v5.14-rc2.

v2->v3:
        - Included patch adding dt binding documentation for LMh nodes.
        - Rebased to v5.13

Thara Gopinath (6):
  firmware: qcom_scm: Introduce SCM calls to access LMh
  thermal: qcom: Add support for LMh driver
  cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support
  arm64: dts: qcom: sdm45: Add support for LMh node
  arm64: dts: qcom: sdm845: Remove cpufreq cooling devices for CPU
    thermal zones
  dt-bindings: thermal: Add dt binding for QCOM LMh

 .../devicetree/bindings/thermal/qcom-lmh.yaml | 100 ++++++++
 arch/arm64/boot/dts/qcom/sdm845.dtsi          | 162 ++----------
 drivers/cpufreq/qcom-cpufreq-hw.c             | 142 +++++++++++
 drivers/firmware/qcom_scm.c                   |  58 +++++
 drivers/firmware/qcom_scm.h                   |   4 +
 drivers/thermal/qcom/Kconfig                  |  10 +
 drivers/thermal/qcom/Makefile                 |   1 +
 drivers/thermal/qcom/lmh.c                    | 232 ++++++++++++++++++
 include/linux/qcom_scm.h                      |  14 ++
 9 files changed, 587 insertions(+), 136 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
 create mode 100644 drivers/thermal/qcom/lmh.c

Comments

Steev Klimaszewski July 27, 2021, 5:44 p.m. UTC | #1
On 7/27/21 10:25 AM, Thara Gopinath wrote:
> Limits Management Hardware(LMh) is a hardware infrastructure on some
> Qualcomm SoCs that can enforce temperature and current limits as programmed
> by software for certain IPs like CPU. On many newer SoCs LMh is configured
> by firmware/TZ and no programming is needed from the kernel side. But on
> certain SoCs like sdm845 the firmware does not do a complete programming of
> the h/w block. On such SoCs kernel software has to explicitly set up the
> temperature limits and turn on various monitoring and enforcing algorithms
> on the hardware.
>
> Introduce support for enabling and programming various limit settings and
> monitoring capabilities of Limits Management Hardware(LMh) associated with
> cpu clusters. Also introduce support in cpufreq hardware driver to monitor
> the interrupt associated with cpu frequency throttling so that this
> information can be conveyed to the schdeuler via thermal pressure
> interface.
>
> With this patch series following cpu performance improvement(30-70%) is
> observed on sdm845. The reasoning here is that without LMh being programmed
> properly from the kernel, the default settings were enabling thermal
> mitigation for CPUs at too low a temperature (around 70-75 degree C).  This
> in turn meant that many a time CPUs were never actually allowed to hit the
> maximum possible/required frequencies.
>
> UnixBench whets and dhry (./Run whets dhry)
> System Benchmarks Index Score
>
>                 Without LMh Support             With LMh Support
> 1 copy test     1353.7                          1773.2
>
> 8 copy tests    4473.6                          7402.3
>
> Sysbench cpu
> sysbench cpu --threads=8 --time=60 --cpu-max-prime=100000 run
>
>                 Without LMh Support             With LMh Support
> Events per
> second                  355                             614
>
> Avg Latency(ms)         21.84                           13.02
>
> v3->v4:
> 	- Rebased to v5.14-rc2.
>
> v2->v3:
>         - Included patch adding dt binding documentation for LMh nodes.
>         - Rebased to v5.13
>
> Thara Gopinath (6):
>   firmware: qcom_scm: Introduce SCM calls to access LMh
>   thermal: qcom: Add support for LMh driver
>   cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support
>   arm64: dts: qcom: sdm45: Add support for LMh node
>   arm64: dts: qcom: sdm845: Remove cpufreq cooling devices for CPU
>     thermal zones
>   dt-bindings: thermal: Add dt binding for QCOM LMh
>
>  .../devicetree/bindings/thermal/qcom-lmh.yaml | 100 ++++++++
>  arch/arm64/boot/dts/qcom/sdm845.dtsi          | 162 ++----------
>  drivers/cpufreq/qcom-cpufreq-hw.c             | 142 +++++++++++
>  drivers/firmware/qcom_scm.c                   |  58 +++++
>  drivers/firmware/qcom_scm.h                   |   4 +
>  drivers/thermal/qcom/Kconfig                  |  10 +
>  drivers/thermal/qcom/Makefile                 |   1 +
>  drivers/thermal/qcom/lmh.c                    | 232 ++++++++++++++++++
>  include/linux/qcom_scm.h                      |  14 ++
>  9 files changed, 587 insertions(+), 136 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
>  create mode 100644 drivers/thermal/qcom/lmh.c
>
Tested-by: Steev Klimaszewski <steev@kali.org>