Commit c17495b0 authored by Viresh Kumar's avatar Viresh Kumar
Browse files

cpufreq: Add callback to register with energy model 



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: default avatarQuentin Perret <qperret@google.com>
Reviewed-by: default avatarLukasz Luba <lukasz.luba@arm.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent bb8c26d9

drivers/cpufreq/cpufreq.c

+13 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/cpufreq.h

+14 −0
Original line number Diff line number Diff line
@@ -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 */