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author | Richard Zhao <richard.zhao@linaro.org> | 2011-12-18 22:10:23 +0800 |
---|---|---|
committer | Amit Daniel Kachhap <amit.kachhap@linaro.org> | 2012-04-13 18:51:46 +0530 |
commit | 9cb264cdf338054269fd583a58f6fd7987eac033 (patch) | |
tree | c94a8a69b2244966cc7d031a6c12a659e4ad59f6 | |
parent | 5fd99e8eb68f2531a2308bf0fb78b8e1af63ecbb (diff) | |
download | linux-topics-9cb264cdf338054269fd583a58f6fd7987eac033.tar.gz |
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>
-rw-r--r-- | arch/arm/kernel/smp.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index addbbe8028c..33af7117167 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -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> @@ -604,3 +605,56 @@ 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 |