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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: Richard Zhao <richard.zhao@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Richard Zhao 2012-09-05 01:08:59 +02:00 committed by Rafael J. Wysocki
parent e1f0b8e9b0
commit ec971ea5f2
1 changed files with 54 additions and 0 deletions
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54
arch/arm/kernel/smp.c
View File

@ -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