Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ec971ea5 authored by Richard Zhao's avatar Richard Zhao Committed by Rafael J. Wysocki
Browse files

ARM: add cpufreq transiton notifier to adjust loops_per_jiffy for smp 



If CONFIG_SMP, cpufreq skips loops_per_jiffy update, because different
arch has different per-cpu loops_per_jiffy definition.

Signed-off-by: default avatarRichard Zhao <richard.zhao@linaro.org>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: default avatarShawn Guo <shawn.guo@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
parent e1f0b8e9

arch/arm/kernel/smp.c

+54 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/percpu.h>

#include <linux/clockchips.h>

#include <linux/completion.h>

#include <linux/cpufreq.h>



#include <linux/atomic.h>

#include <asm/cacheflush.h>
@@ -584,3 +585,56 @@ int setup_profiling_timer(unsigned int multiplier) 
{

	return -EINVAL;

}



#ifdef CONFIG_CPU_FREQ



static DEFINE_PER_CPU(unsigned long, l_p_j_ref);

static DEFINE_PER_CPU(unsigned long, l_p_j_ref_freq);

static unsigned long global_l_p_j_ref;

static unsigned long global_l_p_j_ref_freq;



static int cpufreq_callback(struct notifier_block *nb,

					unsigned long val, void *data)

{

	struct cpufreq_freqs *freq = data;

	int cpu = freq->cpu;



	if (freq->flags & CPUFREQ_CONST_LOOPS)

		return NOTIFY_OK;



	if (!per_cpu(l_p_j_ref, cpu)) {

		per_cpu(l_p_j_ref, cpu) =

			per_cpu(cpu_data, cpu).loops_per_jiffy;

		per_cpu(l_p_j_ref_freq, cpu) = freq->old;

		if (!global_l_p_j_ref) {

			global_l_p_j_ref = loops_per_jiffy;

			global_l_p_j_ref_freq = freq->old;

		}

	}



	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||

	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new) ||

	    (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {

		loops_per_jiffy = cpufreq_scale(global_l_p_j_ref,

						global_l_p_j_ref_freq,

						freq->new);

		per_cpu(cpu_data, cpu).loops_per_jiffy =

			cpufreq_scale(per_cpu(l_p_j_ref, cpu),

					per_cpu(l_p_j_ref_freq, cpu),

					freq->new);

	}

	return NOTIFY_OK;

}



static struct notifier_block cpufreq_notifier = {

	.notifier_call  = cpufreq_callback,

};



static int __init register_cpufreq_notifier(void)

{

	return cpufreq_register_notifier(&cpufreq_notifier,

						CPUFREQ_TRANSITION_NOTIFIER);

}

core_initcall(register_cpufreq_notifier);



#endif