Merge remote-tracking branch 'common/android-4.4' into android-4.4.y

2 files changed, 85 insertions, 0 deletions

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 75f63efd7b43..d43c401ff190 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -112,6 +112,14 @@ config CPU_FREQ_DEFAULT_GOV_INTERACTIVE
 	  loading your cpufreq low-level hardware driver, using the
 	  'interactive' governor for latency-sensitive workloads.
 
+config CPU_FREQ_DEFAULT_GOV_SCHED
+	bool "sched"
+	select CPU_FREQ_GOV_SCHED
+	help
+	  Use the CPUfreq governor 'sched' as default. This scales
+	  cpu frequency using CPU utilization estimates from the
+	  scheduler.
+
 endchoice
 
 config CPU_FREQ_GOV_PERFORMANCE
@@ -207,6 +215,19 @@ config CPU_FREQ_GOV_CONSERVATIVE
 
 	  If in doubt, say N.
 
+config CPU_FREQ_GOV_SCHED
+	bool "'sched' cpufreq governor"
+	depends on CPU_FREQ
+	depends on SMP
+	select CPU_FREQ_GOV_COMMON
+	help
+	  'sched' - this governor scales cpu frequency from the
+	  scheduler as a function of cpu capacity utilization. It does
+	  not evaluate utilization on a periodic basis (as ondemand
+	  does) but instead is event-driven by the scheduler.
+
+	  If in doubt, say N.
+
 comment "CPU frequency scaling drivers"
 
 config CPUFREQ_DT
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index e49512718325..7b728143440d 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -29,6 +29,9 @@
 #include <linux/suspend.h>
 #include <linux/syscore_ops.h>
 #include <linux/tick.h>
+#ifdef CONFIG_SMP
+#include <linux/sched.h>
+#endif
 #include <trace/events/power.h>
 
 static LIST_HEAD(cpufreq_policy_list);
@@ -154,6 +157,12 @@ bool have_governor_per_policy(void)
 }
 EXPORT_SYMBOL_GPL(have_governor_per_policy);
 
+bool cpufreq_driver_is_slow(void)
+{
+	return !(cpufreq_driver->flags & CPUFREQ_DRIVER_FAST);
+}
+EXPORT_SYMBOL_GPL(cpufreq_driver_is_slow);
+
 struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy)
 {
 	if (have_governor_per_policy())
@@ -347,6 +356,50 @@ static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
 #endif
 }
 
+/*********************************************************************
+ *               FREQUENCY INVARIANT CPU CAPACITY                    *
+ *********************************************************************/
+
+static DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE;
+static DEFINE_PER_CPU(unsigned long, max_freq_scale) = SCHED_CAPACITY_SCALE;
+
+static void
+scale_freq_capacity(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs)
+{
+	unsigned long cur = freqs ? freqs->new : policy->cur;
+	unsigned long scale = (cur << SCHED_CAPACITY_SHIFT) / policy->max;
+	struct cpufreq_cpuinfo *cpuinfo = &policy->cpuinfo;
+	int cpu;
+
+	pr_debug("cpus %*pbl cur/cur max freq %lu/%u kHz freq scale %lu\n",
+		 cpumask_pr_args(policy->cpus), cur, policy->max, scale);
+
+	for_each_cpu(cpu, policy->cpus)
+		per_cpu(freq_scale, cpu) = scale;
+
+	if (freqs)
+		return;
+
+	scale = (policy->max << SCHED_CAPACITY_SHIFT) / cpuinfo->max_freq;
+
+	pr_debug("cpus %*pbl cur max/max freq %u/%u kHz max freq scale %lu\n",
+		 cpumask_pr_args(policy->cpus), policy->max, cpuinfo->max_freq,
+		 scale);
+
+	for_each_cpu(cpu, policy->cpus)
+		per_cpu(max_freq_scale, cpu) = scale;
+}
+
+unsigned long cpufreq_scale_freq_capacity(struct sched_domain *sd, int cpu)
+{
+	return per_cpu(freq_scale, cpu);
+}
+
+unsigned long cpufreq_scale_max_freq_capacity(int cpu)
+{
+	return per_cpu(max_freq_scale, cpu);
+}
+
 static void __cpufreq_notify_transition(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs, unsigned int state)
 {
@@ -423,6 +476,9 @@ static void cpufreq_notify_post_transition(struct cpufreq_policy *policy,
 void cpufreq_freq_transition_begin(struct cpufreq_policy *policy,
 		struct cpufreq_freqs *freqs)
 {
+#ifdef CONFIG_SMP
+	int cpu;
+#endif
 
 	/*
 	 * Catch double invocations of _begin() which lead to self-deadlock.
@@ -450,6 +506,12 @@ wait:
 
 	spin_unlock(&policy->transition_lock);
 
+	scale_freq_capacity(policy, freqs);
+#ifdef CONFIG_SMP
+	for_each_cpu(cpu, policy->cpus)
+		trace_cpu_capacity(capacity_curr_of(cpu), cpu);
+#endif
+
 	cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE);
 }
 EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin);
@@ -2126,6 +2188,8 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy,
 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 			CPUFREQ_NOTIFY, new_policy);
 
+	scale_freq_capacity(new_policy, NULL);
+
 	policy->min = new_policy->min;
 	policy->max = new_policy->max;
 	trace_cpu_frequency_limits(policy->max, policy->min, policy->cpu);