[PATCH V3 0/9] Add callback to register with energy model

[PATCH V3 0/9] Add callback to register with energy model

[Viresh Kumar]

Many cpufreq drivers register with the energy model for each policy and
do exactly the same thing. Follow the footsteps of thermal-cooling, to
get it done from the cpufreq core itself.

Provide a new callback, which will be called, if present, by the cpufreq
core at the right moment (more on that in the code's comment). Also
provide a generic implementation that uses dev_pm_opp_of_register_em().

This also allows us to register with the EM at a later point of time,
compared to ->init(), from where the EM core can access cpufreq policy
directly using cpufreq_cpu_get() type of helpers and perform other work,
like marking few frequencies inefficient, this will be done separately.

This is build/boot tested by the bot for a couple of boards.

https://gitlab.com/vireshk/pmko/-/pipelines/351965580

FWIW, I have queued up the series for linux-next to get more testing, but your
reviews are welcome. Thanks.

V2->V3:
- Drop the auto-register part from all logs, this isn't called auto registration
  anymore.
- Call register_em() only for new policies.
- Update scmi driver to register with EM only when required.
- Add Rby tags.

V1->V2:
- Add a callback instead of flag.
- Register before governor is initialized.
- Update scmi driver as well.
- Don't unregister from the EM core.

--
Viresh

Viresh Kumar (9):
  cpufreq: Add callback to register with energy model
  cpufreq: dt: Use .register_em() to register with energy model
  cpufreq: imx6q: Use .register_em() to register with energy model
  cpufreq: mediatek: Use .register_em() to register with energy model
  cpufreq: omap: Use .register_em() to register with energy model
  cpufreq: qcom-cpufreq-hw: Use .register_em() to register with energy
    model
  cpufreq: scpi: Use .register_em() to register with energy model
  cpufreq: vexpress: Use .register_em() to register with energy model
  cpufreq: scmi: Use .register_em() to register with energy model

 drivers/cpufreq/cpufreq-dt.c           |  3 +-
 drivers/cpufreq/cpufreq.c              | 13 ++++++
 drivers/cpufreq/imx6q-cpufreq.c        |  2 +-
 drivers/cpufreq/mediatek-cpufreq.c     |  3 +-
 drivers/cpufreq/omap-cpufreq.c         |  2 +-
 drivers/cpufreq/qcom-cpufreq-hw.c      |  3 +-
 drivers/cpufreq/scmi-cpufreq.c         | 65 +++++++++++++++++---------
 drivers/cpufreq/scpi-cpufreq.c         |  3 +-
 drivers/cpufreq/vexpress-spc-cpufreq.c |  3 +-
 include/linux/cpufreq.h                | 14 ++++++
 10 files changed, 76 insertions(+), 35 deletions(-)

-- 
2.31.1.272.g89b43f80a514

[PATCH V3 6/9] cpufreq: qcom-cpufreq-hw: Use .register_em() to register with energy model

[Viresh Kumar]

Set the newly added .register_em() callback with
cpufreq_register_em_with_opp() to register with the EM core.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/qcom-cpufreq-hw.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index f86859bf76f1..c2e71c430fbf 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -362,8 +362,6 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 		goto error;
 	}
 
-	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
-
 	if (policy_has_boost_freq(policy)) {
 		ret = cpufreq_enable_boost_support();
 		if (ret)
@@ -412,6 +410,7 @@ static struct cpufreq_driver cpufreq_qcom_hw_driver = {
 	.get		= qcom_cpufreq_hw_get,
 	.init		= qcom_cpufreq_hw_cpu_init,
 	.exit		= qcom_cpufreq_hw_cpu_exit,
+	.register_em	= cpufreq_register_em_with_opp,
 	.fast_switch    = qcom_cpufreq_hw_fast_switch,
 	.name		= "qcom-cpufreq-hw",
 	.attr		= qcom_cpufreq_hw_attr,
-- 
2.31.1.272.g89b43f80a514

Re: [PATCH V3 0/9] Add callback to register with energy model

[Dietmar Eggemann]

On 12/08/2021 06:35, Viresh Kumar wrote:
> Many cpufreq drivers register with the energy model for each policy and
> do exactly the same thing. Follow the footsteps of thermal-cooling, to
> get it done from the cpufreq core itself.
> 
> Provide a new callback, which will be called, if present, by the cpufreq
> core at the right moment (more on that in the code's comment). Also
> provide a generic implementation that uses dev_pm_opp_of_register_em().
> 
> This also allows us to register with the EM at a later point of time,
> compared to ->init(), from where the EM core can access cpufreq policy
> directly using cpufreq_cpu_get() type of helpers and perform other work,
> like marking few frequencies inefficient, this will be done separately.
> 
> This is build/boot tested by the bot for a couple of boards.
> 
> https://gitlab.com/vireshk/pmko/-/pipelines/351965580
> 
> FWIW, I have queued up the series for linux-next to get more testing, but your
> reviews are welcome. Thanks.
> 
> V2->V3:
> - Drop the auto-register part from all logs, this isn't called auto registration
>   anymore.
> - Call register_em() only for new policies.
> - Update scmi driver to register with EM only when required.
> - Add Rby tags.

LGTM. Tested on TC2 (vexpress-spc), Juno-r0 (scpi-cpufreq and scmi).

Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>