init android origin source code

1 files changed, 625 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/drivers/cpufreq/cpufreq_conservative.c b/ANDROID_3.4.5/drivers/cpufreq/cpufreq_conservative.c
new file mode 100644
index 00000000..235a340e
--- /dev/null
+++ b/ANDROID_3.4.5/drivers/cpufreq/cpufreq_conservative.c
@@ -0,0 +1,625 @@
+/*
+ *  drivers/cpufreq/cpufreq_conservative.c
+ *
+ *  Copyright (C)  2001 Russell King
+ *            (C)  2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ *                      Jun Nakajima <jun.nakajima@intel.com>
+ *            (C)  2009 Alexander Clouter <alex@digriz.org.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/cpu.h>
+#include <linux/jiffies.h>
+#include <linux/kernel_stat.h>
+#include <linux/mutex.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
+#include <linux/ktime.h>
+#include <linux/sched.h>
+
+/*
+ * dbs is used in this file as a shortform for demandbased switching
+ * It helps to keep variable names smaller, simpler
+ */
+
+#define DEF_FREQUENCY_UP_THRESHOLD		(80)
+#define DEF_FREQUENCY_DOWN_THRESHOLD		(20)
+
+/*
+ * The polling frequency of this governor depends on the capability of
+ * the processor. Default polling frequency is 1000 times the transition
+ * latency of the processor. The governor will work on any processor with
+ * transition latency <= 10mS, using appropriate sampling
+ * rate.
+ * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL)
+ * this governor will not work.
+ * All times here are in uS.
+ */
+#define MIN_SAMPLING_RATE_RATIO			(2)
+
+static unsigned int min_sampling_rate;
+
+#define LATENCY_MULTIPLIER			(1000)
+#define MIN_LATENCY_MULTIPLIER			(100)
+#define DEF_SAMPLING_DOWN_FACTOR		(1)
+#define MAX_SAMPLING_DOWN_FACTOR		(10)
+#define TRANSITION_LATENCY_LIMIT		(10 * 1000 * 1000)
+
+static void do_dbs_timer(struct work_struct *work);
+
+struct cpu_dbs_info_s {
+	cputime64_t prev_cpu_idle;
+	cputime64_t prev_cpu_wall;
+	cputime64_t prev_cpu_nice;
+	struct cpufreq_policy *cur_policy;
+	struct delayed_work work;
+	unsigned int down_skip;
+	unsigned int requested_freq;
+	int cpu;
+	unsigned int enable:1;
+	/*
+	 * percpu mutex that serializes governor limit change with
+	 * do_dbs_timer invocation. We do not want do_dbs_timer to run
+	 * when user is changing the governor or limits.
+	 */
+	struct mutex timer_mutex;
+};
+static DEFINE_PER_CPU(struct cpu_dbs_info_s, cs_cpu_dbs_info);
+
+static unsigned int dbs_enable;	/* number of CPUs using this policy */
+
+/*
+ * dbs_mutex protects dbs_enable in governor start/stop.
+ */
+static DEFINE_MUTEX(dbs_mutex);
+
+static struct dbs_tuners {
+	unsigned int sampling_rate;
+	unsigned int sampling_down_factor;
+	unsigned int up_threshold;
+	unsigned int down_threshold;
+	unsigned int ignore_nice;
+	unsigned int freq_step;
+} dbs_tuners_ins = {
+	.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
+	.down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD,
+	.sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
+	.ignore_nice = 0,
+	.freq_step = 5,
+};
+
+static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
+{
+	u64 idle_time;
+	u64 cur_wall_time;
+	u64 busy_time;
+
+	cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
+
+	busy_time  = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
+	busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
+
+	idle_time = cur_wall_time - busy_time;
+	if (wall)
+		*wall = jiffies_to_usecs(cur_wall_time);
+
+	return jiffies_to_usecs(idle_time);
+}
+
+static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
+{
+	u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
+
+	if (idle_time == -1ULL)
+		return get_cpu_idle_time_jiffy(cpu, wall);
+	else
+		idle_time += get_cpu_iowait_time_us(cpu, wall);
+
+	return idle_time;
+}
+
+/* keep track of frequency transitions */
+static int
+dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
+		     void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cs_cpu_dbs_info,
+							freq->cpu);
+
+	struct cpufreq_policy *policy;
+
+	if (!this_dbs_info->enable)
+		return 0;
+
+	policy = this_dbs_info->cur_policy;
+
+	/*
+	 * we only care if our internally tracked freq moves outside
+	 * the 'valid' ranges of freqency available to us otherwise
+	 * we do not change it
+	*/
+	if (this_dbs_info->requested_freq > policy->max
+			|| this_dbs_info->requested_freq < policy->min)
+		this_dbs_info->requested_freq = freq->new;
+
+	return 0;
+}
+
+static struct notifier_block dbs_cpufreq_notifier_block = {
+	.notifier_call = dbs_cpufreq_notifier
+};
+
+/************************** sysfs interface ************************/
+static ssize_t show_sampling_rate_min(struct kobject *kobj,
+				      struct attribute *attr, char *buf)
+{
+	return sprintf(buf, "%u\n", min_sampling_rate);
+}
+
+define_one_global_ro(sampling_rate_min);
+
+/* cpufreq_conservative Governor Tunables */
+#define show_one(file_name, object)					\
+static ssize_t show_##file_name						\
+(struct kobject *kobj, struct attribute *attr, char *buf)		\
+{									\
+	return sprintf(buf, "%u\n", dbs_tuners_ins.object);		\
+}
+show_one(sampling_rate, sampling_rate);
+show_one(sampling_down_factor, sampling_down_factor);
+show_one(up_threshold, up_threshold);
+show_one(down_threshold, down_threshold);
+show_one(ignore_nice_load, ignore_nice);
+show_one(freq_step, freq_step);
+
+static ssize_t store_sampling_down_factor(struct kobject *a,
+					  struct attribute *b,
+					  const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+	ret = sscanf(buf, "%u", &input);
+
+	if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1)
+		return -EINVAL;
+
+	dbs_tuners_ins.sampling_down_factor = input;
+	return count;
+}
+
+static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
+				   const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+	ret = sscanf(buf, "%u", &input);
+
+	if (ret != 1)
+		return -EINVAL;
+
+	dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate);
+	return count;
+}
+
+static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
+				  const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+	ret = sscanf(buf, "%u", &input);
+
+	if (ret != 1 || input > 100 ||
+			input <= dbs_tuners_ins.down_threshold)
+		return -EINVAL;
+
+	dbs_tuners_ins.up_threshold = input;
+	return count;
+}
+
+static ssize_t store_down_threshold(struct kobject *a, struct attribute *b,
+				    const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+	ret = sscanf(buf, "%u", &input);
+
+	/* cannot be lower than 11 otherwise freq will not fall */
+	if (ret != 1 || input < 11 || input > 100 ||
+			input >= dbs_tuners_ins.up_threshold)
+		return -EINVAL;
+
+	dbs_tuners_ins.down_threshold = input;
+	return count;
+}
+
+static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
+				      const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+
+	unsigned int j;
+
+	ret = sscanf(buf, "%u", &input);
+	if (ret != 1)
+		return -EINVAL;
+
+	if (input > 1)
+		input = 1;
+
+	if (input == dbs_tuners_ins.ignore_nice) /* nothing to do */
+		return count;
+
+	dbs_tuners_ins.ignore_nice = input;
+
+	/* we need to re-evaluate prev_cpu_idle */
+	for_each_online_cpu(j) {
+		struct cpu_dbs_info_s *dbs_info;
+		dbs_info = &per_cpu(cs_cpu_dbs_info, j);
+		dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
+						&dbs_info->prev_cpu_wall);
+		if (dbs_tuners_ins.ignore_nice)
+			dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+	}
+	return count;
+}
+
+static ssize_t store_freq_step(struct kobject *a, struct attribute *b,
+			       const char *buf, size_t count)
+{
+	unsigned int input;
+	int ret;
+	ret = sscanf(buf, "%u", &input);
+
+	if (ret != 1)
+		return -EINVAL;
+
+	if (input > 100)
+		input = 100;
+
+	/* no need to test here if freq_step is zero as the user might actually
+	 * want this, they would be crazy though :) */
+	dbs_tuners_ins.freq_step = input;
+	return count;
+}
+
+define_one_global_rw(sampling_rate);
+define_one_global_rw(sampling_down_factor);
+define_one_global_rw(up_threshold);
+define_one_global_rw(down_threshold);
+define_one_global_rw(ignore_nice_load);
+define_one_global_rw(freq_step);
+
+static struct attribute *dbs_attributes[] = {
+	&sampling_rate_min.attr,
+	&sampling_rate.attr,
+	&sampling_down_factor.attr,
+	&up_threshold.attr,
+	&down_threshold.attr,
+	&ignore_nice_load.attr,
+	&freq_step.attr,
+	NULL
+};
+
+static struct attribute_group dbs_attr_group = {
+	.attrs = dbs_attributes,
+	.name = "conservative",
+};
+
+/************************** sysfs end ************************/
+
+static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
+{
+	unsigned int load = 0;
+	unsigned int max_load = 0;
+	unsigned int freq_target;
+
+	struct cpufreq_policy *policy;
+	unsigned int j;
+
+	policy = this_dbs_info->cur_policy;
+
+	/*
+	 * Every sampling_rate, we check, if current idle time is less
+	 * than 20% (default), then we try to increase frequency
+	 * Every sampling_rate*sampling_down_factor, we check, if current
+	 * idle time is more than 80%, then we try to decrease frequency
+	 *
+	 * Any frequency increase takes it to the maximum frequency.
+	 * Frequency reduction happens at minimum steps of
+	 * 5% (default) of maximum frequency
+	 */
+
+	/* Get Absolute Load */
+	for_each_cpu(j, policy->cpus) {
+		struct cpu_dbs_info_s *j_dbs_info;
+		cputime64_t cur_wall_time, cur_idle_time;
+		unsigned int idle_time, wall_time;
+
+		j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
+
+		cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+
+		wall_time = (unsigned int)
+			(cur_wall_time - j_dbs_info->prev_cpu_wall);
+		j_dbs_info->prev_cpu_wall = cur_wall_time;
+
+		idle_time = (unsigned int)
+			(cur_idle_time - j_dbs_info->prev_cpu_idle);
+		j_dbs_info->prev_cpu_idle = cur_idle_time;
+
+		if (dbs_tuners_ins.ignore_nice) {
+			u64 cur_nice;
+			unsigned long cur_nice_jiffies;
+
+			cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
+					 j_dbs_info->prev_cpu_nice;
+			/*
+			 * Assumption: nice time between sampling periods will
+			 * be less than 2^32 jiffies for 32 bit sys
+			 */
+			cur_nice_jiffies = (unsigned long)
+					cputime64_to_jiffies64(cur_nice);
+
+			j_dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+			idle_time += jiffies_to_usecs(cur_nice_jiffies);
+		}
+
+		if (unlikely(!wall_time || wall_time < idle_time))
+			continue;
+
+		load = 100 * (wall_time - idle_time) / wall_time;
+
+		if (load > max_load)
+			max_load = load;
+	}
+
+	/*
+	 * break out if we 'cannot' reduce the speed as the user might
+	 * want freq_step to be zero
+	 */
+	if (dbs_tuners_ins.freq_step == 0)
+		return;
+
+	/* Check for frequency increase */
+	if (max_load > dbs_tuners_ins.up_threshold) {
+		this_dbs_info->down_skip = 0;
+
+		/* if we are already at full speed then break out early */
+		if (this_dbs_info->requested_freq == policy->max)
+			return;
+
+		freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
+
+		/* max freq cannot be less than 100. But who knows.... */
+		if (unlikely(freq_target == 0))
+			freq_target = 5;
+
+		this_dbs_info->requested_freq += freq_target;
+		if (this_dbs_info->requested_freq > policy->max)
+			this_dbs_info->requested_freq = policy->max;
+
+		__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
+			CPUFREQ_RELATION_H);
+		return;
+	}
+
+	/*
+	 * The optimal frequency is the frequency that is the lowest that
+	 * can support the current CPU usage without triggering the up
+	 * policy. To be safe, we focus 10 points under the threshold.
+	 */
+	if (max_load < (dbs_tuners_ins.down_threshold - 10)) {
+		freq_target = (dbs_tuners_ins.freq_step * policy->max) / 100;
+
+		this_dbs_info->requested_freq -= freq_target;
+		if (this_dbs_info->requested_freq < policy->min)
+			this_dbs_info->requested_freq = policy->min;
+
+		/*
+		 * if we cannot reduce the frequency anymore, break out early
+		 */
+		if (policy->cur == policy->min)
+			return;
+
+		__cpufreq_driver_target(policy, this_dbs_info->requested_freq,
+				CPUFREQ_RELATION_H);
+		return;
+	}
+}
+
+static void do_dbs_timer(struct work_struct *work)
+{
+	struct cpu_dbs_info_s *dbs_info =
+		container_of(work, struct cpu_dbs_info_s, work.work);
+	unsigned int cpu = dbs_info->cpu;
+
+	/* We want all CPUs to do sampling nearly on same jiffy */
+	int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+
+	delay -= jiffies % delay;
+
+	mutex_lock(&dbs_info->timer_mutex);
+
+	dbs_check_cpu(dbs_info);
+
+	schedule_delayed_work_on(cpu, &dbs_info->work, delay);
+	mutex_unlock(&dbs_info->timer_mutex);
+}
+
+static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
+{
+	/* We want all CPUs to do sampling nearly on same jiffy */
+	int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
+	delay -= jiffies % delay;
+
+	dbs_info->enable = 1;
+	INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer);
+	schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay);
+}
+
+static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
+{
+	dbs_info->enable = 0;
+	cancel_delayed_work_sync(&dbs_info->work);
+}
+
+static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
+				   unsigned int event)
+{
+	unsigned int cpu = policy->cpu;
+	struct cpu_dbs_info_s *this_dbs_info;
+	unsigned int j;
+	int rc;
+
+	this_dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
+
+	switch (event) {
+	case CPUFREQ_GOV_START:
+		if ((!cpu_online(cpu)) || (!policy->cur))
+			return -EINVAL;
+
+		mutex_lock(&dbs_mutex);
+
+		for_each_cpu(j, policy->cpus) {
+			struct cpu_dbs_info_s *j_dbs_info;
+			j_dbs_info = &per_cpu(cs_cpu_dbs_info, j);
+			j_dbs_info->cur_policy = policy;
+
+			j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
+						&j_dbs_info->prev_cpu_wall);
+			if (dbs_tuners_ins.ignore_nice)
+				j_dbs_info->prev_cpu_nice =
+						kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+		}
+		this_dbs_info->down_skip = 0;
+		this_dbs_info->requested_freq = policy->cur;
+
+		mutex_init(&this_dbs_info->timer_mutex);
+		dbs_enable++;
+		/*
+		 * Start the timerschedule work, when this governor
+		 * is used for first time
+		 */
+		if (dbs_enable == 1) {
+			unsigned int latency;
+			/* policy latency is in nS. Convert it to uS first */
+			latency = policy->cpuinfo.transition_latency / 1000;
+			if (latency == 0)
+				latency = 1;
+
+			rc = sysfs_create_group(cpufreq_global_kobject,
+						&dbs_attr_group);
+			if (rc) {
+				mutex_unlock(&dbs_mutex);
+				return rc;
+			}
+
+			/*
+			 * conservative does not implement micro like ondemand
+			 * governor, thus we are bound to jiffes/HZ
+			 */
+			min_sampling_rate =
+				MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
+			/* Bring kernel and HW constraints together */
+			min_sampling_rate = max(min_sampling_rate,
+					MIN_LATENCY_MULTIPLIER * latency);
+			dbs_tuners_ins.sampling_rate =
+				max(min_sampling_rate,
+				    latency * LATENCY_MULTIPLIER);
+
+			cpufreq_register_notifier(
+					&dbs_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+		}
+		mutex_unlock(&dbs_mutex);
+
+		dbs_timer_init(this_dbs_info);
+
+		break;
+
+	case CPUFREQ_GOV_STOP:
+		dbs_timer_exit(this_dbs_info);
+
+		mutex_lock(&dbs_mutex);
+		dbs_enable--;
+		mutex_destroy(&this_dbs_info->timer_mutex);
+
+		/*
+		 * Stop the timerschedule work, when this governor
+		 * is used for first time
+		 */
+		if (dbs_enable == 0)
+			cpufreq_unregister_notifier(
+					&dbs_cpufreq_notifier_block,
+					CPUFREQ_TRANSITION_NOTIFIER);
+
+		mutex_unlock(&dbs_mutex);
+		if (!dbs_enable)
+			sysfs_remove_group(cpufreq_global_kobject,
+					   &dbs_attr_group);
+
+		break;
+
+	case CPUFREQ_GOV_LIMITS:
+		mutex_lock(&this_dbs_info->timer_mutex);
+		if (policy->max < this_dbs_info->cur_policy->cur)
+			__cpufreq_driver_target(
+					this_dbs_info->cur_policy,
+					policy->max, CPUFREQ_RELATION_H);
+		else if (policy->min > this_dbs_info->cur_policy->cur)
+			__cpufreq_driver_target(
+					this_dbs_info->cur_policy,
+					policy->min, CPUFREQ_RELATION_L);
+		mutex_unlock(&this_dbs_info->timer_mutex);
+
+		break;
+	}
+	return 0;
+}
+
+#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
+static
+#endif
+struct cpufreq_governor cpufreq_gov_conservative = {
+	.name			= "conservative",
+	.governor		= cpufreq_governor_dbs,
+	.max_transition_latency	= TRANSITION_LATENCY_LIMIT,
+	.owner			= THIS_MODULE,
+};
+
+static int __init cpufreq_gov_dbs_init(void)
+{
+	return cpufreq_register_governor(&cpufreq_gov_conservative);
+}
+
+static void __exit cpufreq_gov_dbs_exit(void)
+{
+	cpufreq_unregister_governor(&cpufreq_gov_conservative);
+}
+
+
+MODULE_AUTHOR("Alexander Clouter <alex@digriz.org.uk>");
+MODULE_DESCRIPTION("'cpufreq_conservative' - A dynamic cpufreq governor for "
+		"Low Latency Frequency Transition capable processors "
+		"optimised for use in a battery environment");
+MODULE_LICENSE("GPL");
+
+#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE
+fs_initcall(cpufreq_gov_dbs_init);
+#else
+module_init(cpufreq_gov_dbs_init);
+#endif
+module_exit(cpufreq_gov_dbs_exit);