diff mbox series

[V3,1/9] cpufreq: Add callback to register with energy model

Message ID c17495b01b72b53bd290f442d39b060e015c7aea.1628742634.git.viresh.kumar@linaro.org (mailing list archive)
State New, archived
Delegated to: viresh kumar
Headers show
Series Add callback to register with energy model | expand

Commit Message

Viresh Kumar Aug. 12, 2021, 4:35 a.m. UTC
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.

Reviewed-by: Quentin Perret <qperret@google.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/cpufreq/cpufreq.c | 13 +++++++++++++
 include/linux/cpufreq.h   | 14 ++++++++++++++
 2 files changed, 27 insertions(+)

Comments

Vincent Donnefort Sept. 1, 2021, 8:32 a.m. UTC | #1
On Thu, Aug 12, 2021 at 10:05:14AM +0530, 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.
> 
> Reviewed-by: Quentin Perret <qperret@google.com>
> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
>  drivers/cpufreq/cpufreq.c | 13 +++++++++++++
>  include/linux/cpufreq.h   | 14 ++++++++++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 45f3416988f1..d301f39248a0 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -1491,6 +1491,19 @@ static int cpufreq_online(unsigned int cpu)
>  		write_lock_irqsave(&cpufreq_driver_lock, flags);
>  		list_add(&policy->policy_list, &cpufreq_policy_list);
>  		write_unlock_irqrestore(&cpufreq_driver_lock, flags);
> +
> +		/*
> +		 * Register with the energy model before
> +		 * sched_cpufreq_governor_change() is called, which will result
> +		 * in rebuilding of the sched domains, which should only be done
> +		 * once the energy model is properly initialized for the policy
> +		 * first.
> +		 *
> +		 * Also, this should be called before the policy is registered
> +		 * with cooling framework.
> +		 */
> +		if (cpufreq_driver->register_em)
> +			cpufreq_driver->register_em(policy);
>  	}
>  
>  	ret = cpufreq_init_policy(policy);
> diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
> index 9fd719475fcd..c65a1d7385f8 100644
> --- a/include/linux/cpufreq.h
> +++ b/include/linux/cpufreq.h
> @@ -9,10 +9,12 @@
>  #define _LINUX_CPUFREQ_H
>  
>  #include <linux/clk.h>
> +#include <linux/cpu.h>
>  #include <linux/cpumask.h>
>  #include <linux/completion.h>
>  #include <linux/kobject.h>
>  #include <linux/notifier.h>
> +#include <linux/pm_opp.h>
>  #include <linux/pm_qos.h>
>  #include <linux/spinlock.h>
>  #include <linux/sysfs.h>
> @@ -373,6 +375,12 @@ struct cpufreq_driver {
>  	/* platform specific boost support code */
>  	bool		boost_enabled;
>  	int		(*set_boost)(struct cpufreq_policy *policy, int state);
> +
> +	/*
> +	 * Set by drivers that want to register with the energy model after the
> +	 * policy is properly initialized, but before the governor is started.
> +	 */
> +	void		(*register_em)(struct cpufreq_policy *policy);
>  };
>  
>  /* flags */
> @@ -1046,4 +1054,10 @@ unsigned int cpufreq_generic_get(unsigned int cpu);
>  void cpufreq_generic_init(struct cpufreq_policy *policy,
>  		struct cpufreq_frequency_table *table,
>  		unsigned int transition_latency);
> +
> +static inline void cpufreq_register_em_with_opp(struct cpufreq_policy *policy)
> +{
> +	dev_pm_opp_of_register_em(get_cpu_device(policy->cpu),
> +				  policy->related_cpus);
> +}
>  #endif /* _LINUX_CPUFREQ_H */
> -- 
> 2.31.1.272.g89b43f80a514
> 

Tested on Hikey960 while working on the inefficient OPPs support.

Tested-by: Vincent Donnefort <vincent.donnefort@arm.com>
diff mbox series

Patch

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 45f3416988f1..d301f39248a0 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1491,6 +1491,19 @@  static int cpufreq_online(unsigned int cpu)
 		write_lock_irqsave(&cpufreq_driver_lock, flags);
 		list_add(&policy->policy_list, &cpufreq_policy_list);
 		write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+		/*
+		 * Register with the energy model before
+		 * sched_cpufreq_governor_change() is called, which will result
+		 * in rebuilding of the sched domains, which should only be done
+		 * once the energy model is properly initialized for the policy
+		 * first.
+		 *
+		 * Also, this should be called before the policy is registered
+		 * with cooling framework.
+		 */
+		if (cpufreq_driver->register_em)
+			cpufreq_driver->register_em(policy);
 	}
 
 	ret = cpufreq_init_policy(policy);
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 9fd719475fcd..c65a1d7385f8 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -9,10 +9,12 @@ 
 #define _LINUX_CPUFREQ_H
 
 #include <linux/clk.h>
+#include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <linux/completion.h>
 #include <linux/kobject.h>
 #include <linux/notifier.h>
+#include <linux/pm_opp.h>
 #include <linux/pm_qos.h>
 #include <linux/spinlock.h>
 #include <linux/sysfs.h>
@@ -373,6 +375,12 @@  struct cpufreq_driver {
 	/* platform specific boost support code */
 	bool		boost_enabled;
 	int		(*set_boost)(struct cpufreq_policy *policy, int state);
+
+	/*
+	 * Set by drivers that want to register with the energy model after the
+	 * policy is properly initialized, but before the governor is started.
+	 */
+	void		(*register_em)(struct cpufreq_policy *policy);
 };
 
 /* flags */
@@ -1046,4 +1054,10 @@  unsigned int cpufreq_generic_get(unsigned int cpu);
 void cpufreq_generic_init(struct cpufreq_policy *policy,
 		struct cpufreq_frequency_table *table,
 		unsigned int transition_latency);
+
+static inline void cpufreq_register_em_with_opp(struct cpufreq_policy *policy)
+{
+	dev_pm_opp_of_register_em(get_cpu_device(policy->cpu),
+				  policy->related_cpus);
+}
 #endif /* _LINUX_CPUFREQ_H */