diff mbox series

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

Message ID c17495b01b72b53bd290f442d39b060e015c7aea.1628742634.git.viresh.kumar@linaro.org
State Accepted
Commit c17495b01b72b53bd290f442d39b060e015c7aea
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(+)

-- 
2.31.1.272.g89b43f80a514

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 */