Commit bbce8eaa authored by Ionela Voinescu's avatar Ionela Voinescu Committed by Catalin Marinas
Browse files

cpufreq: add function to get the hardware max frequency 



Add weak function to return the hardware maximum frequency of a CPU,
with the default implementation returning cpuinfo.max_freq, which is
the best information we can generically get from the cpufreq framework.

The default can be overwritten by a strong function in platforms
that want to provide an alternative implementation, with more accurate
information, obtained either from hardware or firmware.

Signed-off-by: default avatarIonela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: default avatarValentin Schneider <valentin.schneider@arm.com>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 6abde908

drivers/cpufreq/cpufreq.c

+20 −0
Original line number Diff line number Diff line
@@ -1725,6 +1725,26 @@ unsigned int cpufreq_quick_get_max(unsigned int cpu) 
}

EXPORT_SYMBOL(cpufreq_quick_get_max);



/**

 * cpufreq_get_hw_max_freq - get the max hardware frequency of the CPU

 * @cpu: CPU number

 *

 * The default return value is the max_freq field of cpuinfo.

 */

__weak unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)

{

	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);

	unsigned int ret_freq = 0;



	if (policy) {

		ret_freq = policy->cpuinfo.max_freq;

		cpufreq_cpu_put(policy);

	}



	return ret_freq;

}

EXPORT_SYMBOL(cpufreq_get_hw_max_freq);



static unsigned int __cpufreq_get(struct cpufreq_policy *policy)

{

	if (unlikely(policy_is_inactive(policy)))

include/linux/cpufreq.h

+5 −0
Original line number Diff line number Diff line
@@ -205,6 +205,7 @@ static inline bool policy_is_shared(struct cpufreq_policy *policy) 
unsigned int cpufreq_get(unsigned int cpu);

unsigned int cpufreq_quick_get(unsigned int cpu);

unsigned int cpufreq_quick_get_max(unsigned int cpu);

unsigned int cpufreq_get_hw_max_freq(unsigned int cpu);

void disable_cpufreq(void);



u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy);
@@ -232,6 +233,10 @@ static inline unsigned int cpufreq_quick_get_max(unsigned int cpu) 
{

	return 0;

}

static inline unsigned int cpufreq_get_hw_max_freq(unsigned int cpu)

{

	return 0;

}

static inline void disable_cpufreq(void) { }

#endif

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