[PATCH V3 1/9] cpufreq: Add callback to register with energy model
From: Viresh Kumar
Date: Thu Aug 12 2021 - 00:35:57 EST
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@xxxxxxxxxx>
Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
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