cpufreq: provide default frequency-invariance setter function

Frequency-invariant accounting support based on the ratio of current
frequency and maximum supported frequency is an optional feature an arch
can implement.

Since there are cpufreq drivers (e.g. cpufreq-dt) which can be build for
different arch's a default implementation of the frequency-invariance
setter function arch_set_freq_scale() is needed.

This default implementation is an empty weak function which will be
overwritten by a strong function in case the arch provides one.

The setter function passes the cpumask of related (to the frequency
change) cpus (online and offline cpus), the (new) current frequency and
the maximum supported frequency.

Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ea43b147a7fe93adc3c8229327532debec429486..e38cab3fbe4cec98c314f5e4ef267f24f1c08ec7 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2430,6 +2430,17 @@ int cpufreq_boost_enabled(void)
 }
 EXPORT_SYMBOL_GPL(cpufreq_boost_enabled);
 
+/*********************************************************************
+ *               FREQUENCY INVARIANT ACCOUNTING SUPPORT              *
+ *********************************************************************/
+
+__weak void arch_set_freq_scale(struct cpumask *cpus,
+                               unsigned long cur_freq,
+                               unsigned long max_freq)
+{
+}
+EXPORT_SYMBOL_GPL(arch_set_freq_scale);
+
 /*********************************************************************
  *               REGISTER / UNREGISTER CPUFREQ DRIVER                *
  *********************************************************************/

diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index cbf85c4c745f856b6c5e8f4f6d6c3dad80b887c7..699b38c6a64ba18d350ae9da4bd13dcee1d37952 100644 (file)
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -919,6 +919,8 @@ static inline bool policy_has_boost_freq(struct cpufreq_policy *policy)
 
 extern void arch_freq_prepare_all(void);
 extern unsigned int arch_freq_get_on_cpu(int cpu);
+extern void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
+                               unsigned long max_freq);
 
 /* the following are really really optional */
 extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs;