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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /ANDROID_3.4.5/drivers/cpufreq/cpufreq_ondemand.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'ANDROID_3.4.5/drivers/cpufreq/cpufreq_ondemand.c')
-rw-r--r--ANDROID_3.4.5/drivers/cpufreq/cpufreq_ondemand.c814
1 files changed, 0 insertions, 814 deletions
diff --git a/ANDROID_3.4.5/drivers/cpufreq/cpufreq_ondemand.c b/ANDROID_3.4.5/drivers/cpufreq/cpufreq_ondemand.c
deleted file mode 100644
index 836e9b06..00000000
--- a/ANDROID_3.4.5/drivers/cpufreq/cpufreq_ondemand.c
+++ /dev/null
@@ -1,814 +0,0 @@
-/*
- * drivers/cpufreq/cpufreq_ondemand.c
- *
- * Copyright (C) 2001 Russell King
- * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
- * Jun Nakajima <jun.nakajima@intel.com>
- *
- * 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_DOWN_DIFFERENTIAL (10)
-#define DEF_FREQUENCY_UP_THRESHOLD (80)
-#define DEF_SAMPLING_DOWN_FACTOR (1)
-#define MAX_SAMPLING_DOWN_FACTOR (100000)
-#define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3)
-#define MICRO_FREQUENCY_UP_THRESHOLD (95)
-#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000)
-#define MIN_FREQUENCY_UP_THRESHOLD (11)
-#define MAX_FREQUENCY_UP_THRESHOLD (100)
-
-/*
- * 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 TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000)
-
-static void do_dbs_timer(struct work_struct *work);
-static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
- unsigned int event);
-
-#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
-static
-#endif
-struct cpufreq_governor cpufreq_gov_ondemand = {
- .name = "ondemand",
- .governor = cpufreq_governor_dbs,
- .max_transition_latency = TRANSITION_LATENCY_LIMIT,
- .owner = THIS_MODULE,
-};
-
-/* Sampling types */
-enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
-
-struct cpu_dbs_info_s {
- cputime64_t prev_cpu_idle;
- cputime64_t prev_cpu_iowait;
- cputime64_t prev_cpu_wall;
- cputime64_t prev_cpu_nice;
- struct cpufreq_policy *cur_policy;
- struct delayed_work work;
- struct cpufreq_frequency_table *freq_table;
- unsigned int freq_lo;
- unsigned int freq_lo_jiffies;
- unsigned int freq_hi_jiffies;
- unsigned int rate_mult;
- int cpu;
- unsigned int sample_type: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, od_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 up_threshold;
- unsigned int down_differential;
- unsigned int ignore_nice;
- unsigned int sampling_down_factor;
- unsigned int powersave_bias;
- unsigned int io_is_busy;
-} dbs_tuners_ins = {
- .up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
- .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR,
- .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL,
- .ignore_nice = 0,
- .powersave_bias = 0,
-};
-
-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;
-}
-
-static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall)
-{
- u64 iowait_time = get_cpu_iowait_time_us(cpu, wall);
-
- if (iowait_time == -1ULL)
- return 0;
-
- return iowait_time;
-}
-
-/*
- * Find right freq to be set now with powersave_bias on.
- * Returns the freq_hi to be used right now and will set freq_hi_jiffies,
- * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs.
- */
-static unsigned int powersave_bias_target(struct cpufreq_policy *policy,
- unsigned int freq_next,
- unsigned int relation)
-{
- unsigned int freq_req, freq_reduc, freq_avg;
- unsigned int freq_hi, freq_lo;
- unsigned int index = 0;
- unsigned int jiffies_total, jiffies_hi, jiffies_lo;
- struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info,
- policy->cpu);
-
- if (!dbs_info->freq_table) {
- dbs_info->freq_lo = 0;
- dbs_info->freq_lo_jiffies = 0;
- return freq_next;
- }
-
- cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next,
- relation, &index);
- freq_req = dbs_info->freq_table[index].frequency;
- freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000;
- freq_avg = freq_req - freq_reduc;
-
- /* Find freq bounds for freq_avg in freq_table */
- index = 0;
- cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg,
- CPUFREQ_RELATION_H, &index);
- freq_lo = dbs_info->freq_table[index].frequency;
- index = 0;
- cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg,
- CPUFREQ_RELATION_L, &index);
- freq_hi = dbs_info->freq_table[index].frequency;
-
- /* Find out how long we have to be in hi and lo freqs */
- if (freq_hi == freq_lo) {
- dbs_info->freq_lo = 0;
- dbs_info->freq_lo_jiffies = 0;
- return freq_lo;
- }
- jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
- jiffies_hi = (freq_avg - freq_lo) * jiffies_total;
- jiffies_hi += ((freq_hi - freq_lo) / 2);
- jiffies_hi /= (freq_hi - freq_lo);
- jiffies_lo = jiffies_total - jiffies_hi;
- dbs_info->freq_lo = freq_lo;
- dbs_info->freq_lo_jiffies = jiffies_lo;
- dbs_info->freq_hi_jiffies = jiffies_hi;
- return freq_hi;
-}
-
-static void ondemand_powersave_bias_init_cpu(int cpu)
-{
- struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
- dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
- dbs_info->freq_lo = 0;
-}
-
-static void ondemand_powersave_bias_init(void)
-{
- int i;
- for_each_online_cpu(i) {
- ondemand_powersave_bias_init_cpu(i);
- }
-}
-
-/************************** 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_ondemand 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(io_is_busy, io_is_busy);
-show_one(up_threshold, up_threshold);
-show_one(sampling_down_factor, sampling_down_factor);
-show_one(ignore_nice_load, ignore_nice);
-show_one(powersave_bias, powersave_bias);
-
-/**
- * update_sampling_rate - update sampling rate effective immediately if needed.
- * @new_rate: new sampling rate
- *
- * If new rate is smaller than the old, simply updaing
- * dbs_tuners_int.sampling_rate might not be appropriate. For example,
- * if the original sampling_rate was 1 second and the requested new sampling
- * rate is 10 ms because the user needs immediate reaction from ondemand
- * governor, but not sure if higher frequency will be required or not,
- * then, the governor may change the sampling rate too late; up to 1 second
- * later. Thus, if we are reducing the sampling rate, we need to make the
- * new value effective immediately.
- */
-static void update_sampling_rate(unsigned int new_rate)
-{
- int cpu;
-
- dbs_tuners_ins.sampling_rate = new_rate
- = max(new_rate, min_sampling_rate);
-
- for_each_online_cpu(cpu) {
- struct cpufreq_policy *policy;
- struct cpu_dbs_info_s *dbs_info;
- unsigned long next_sampling, appointed_at;
-
- policy = cpufreq_cpu_get(cpu);
- if (!policy)
- continue;
- dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu);
- cpufreq_cpu_put(policy);
-
- mutex_lock(&dbs_info->timer_mutex);
-
- if (!delayed_work_pending(&dbs_info->work)) {
- mutex_unlock(&dbs_info->timer_mutex);
- continue;
- }
-
- next_sampling = jiffies + usecs_to_jiffies(new_rate);
- appointed_at = dbs_info->work.timer.expires;
-
-
- if (time_before(next_sampling, appointed_at)) {
-
- mutex_unlock(&dbs_info->timer_mutex);
- cancel_delayed_work_sync(&dbs_info->work);
- mutex_lock(&dbs_info->timer_mutex);
-
- schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work,
- usecs_to_jiffies(new_rate));
-
- }
- mutex_unlock(&dbs_info->timer_mutex);
- }
-}
-
-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;
- update_sampling_rate(input);
- return count;
-}
-
-static ssize_t store_io_is_busy(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.io_is_busy = !!input;
- 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 > MAX_FREQUENCY_UP_THRESHOLD ||
- input < MIN_FREQUENCY_UP_THRESHOLD) {
- return -EINVAL;
- }
- dbs_tuners_ins.up_threshold = input;
- return count;
-}
-
-static ssize_t store_sampling_down_factor(struct kobject *a,
- struct attribute *b, const char *buf, size_t count)
-{
- unsigned int input, j;
- 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;
-
- /* Reset down sampling multiplier in case it was active */
- for_each_online_cpu(j) {
- struct cpu_dbs_info_s *dbs_info;
- dbs_info = &per_cpu(od_cpu_dbs_info, j);
- dbs_info->rate_mult = 1;
- }
- 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(od_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_powersave_bias(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 > 1000)
- input = 1000;
-
- dbs_tuners_ins.powersave_bias = input;
- ondemand_powersave_bias_init();
- return count;
-}
-
-define_one_global_rw(sampling_rate);
-define_one_global_rw(io_is_busy);
-define_one_global_rw(up_threshold);
-define_one_global_rw(sampling_down_factor);
-define_one_global_rw(ignore_nice_load);
-define_one_global_rw(powersave_bias);
-
-static struct attribute *dbs_attributes[] = {
- &sampling_rate_min.attr,
- &sampling_rate.attr,
- &up_threshold.attr,
- &sampling_down_factor.attr,
- &ignore_nice_load.attr,
- &powersave_bias.attr,
- &io_is_busy.attr,
- NULL
-};
-
-static struct attribute_group dbs_attr_group = {
- .attrs = dbs_attributes,
- .name = "ondemand",
-};
-
-/************************** sysfs end ************************/
-
-static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
-{
- if (dbs_tuners_ins.powersave_bias)
- freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H);
- else if (p->cur == p->max)
- return;
-
- __cpufreq_driver_target(p, freq, dbs_tuners_ins.powersave_bias ?
- CPUFREQ_RELATION_L : CPUFREQ_RELATION_H);
-}
-
-static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
-{
- unsigned int max_load_freq;
-
- struct cpufreq_policy *policy;
- unsigned int j;
-
- this_dbs_info->freq_lo = 0;
- 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, we look for a the lowest
- * frequency which can sustain the load while keeping idle time over
- * 30%. If such a frequency exist, we try to decrease to this frequency.
- *
- * Any frequency increase takes it to the maximum frequency.
- * Frequency reduction happens at minimum steps of
- * 5% (default) of current frequency
- */
-
- /* Get Absolute Load - in terms of freq */
- max_load_freq = 0;
-
- for_each_cpu(j, policy->cpus) {
- struct cpu_dbs_info_s *j_dbs_info;
- cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
- unsigned int idle_time, wall_time, iowait_time;
- unsigned int load, load_freq;
- int freq_avg;
-
- j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
-
- cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
- cur_iowait_time = get_cpu_iowait_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;
-
- iowait_time = (unsigned int)
- (cur_iowait_time - j_dbs_info->prev_cpu_iowait);
- j_dbs_info->prev_cpu_iowait = cur_iowait_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);
- }
-
- /*
- * For the purpose of ondemand, waiting for disk IO is an
- * indication that you're performance critical, and not that
- * the system is actually idle. So subtract the iowait time
- * from the cpu idle time.
- */
-
- if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time)
- idle_time -= iowait_time;
-
- if (unlikely(!wall_time || wall_time < idle_time))
- continue;
-
- load = 100 * (wall_time - idle_time) / wall_time;
-
- freq_avg = __cpufreq_driver_getavg(policy, j);
- if (freq_avg <= 0)
- freq_avg = policy->cur;
-
- load_freq = load * freq_avg;
- if (load_freq > max_load_freq)
- max_load_freq = load_freq;
- }
-
- /* Check for frequency increase */
- if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) {
- /* If switching to max speed, apply sampling_down_factor */
- if (policy->cur < policy->max)
- this_dbs_info->rate_mult =
- dbs_tuners_ins.sampling_down_factor;
- dbs_freq_increase(policy, policy->max);
- return;
- }
-
- /* Check for frequency decrease */
- /* if we cannot reduce the frequency anymore, break out early */
- if (policy->cur == policy->min)
- 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_freq <
- (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) *
- policy->cur) {
- unsigned int freq_next;
- freq_next = max_load_freq /
- (dbs_tuners_ins.up_threshold -
- dbs_tuners_ins.down_differential);
-
- /* No longer fully busy, reset rate_mult */
- this_dbs_info->rate_mult = 1;
-
- if (freq_next < policy->min)
- freq_next = policy->min;
-
- if (!dbs_tuners_ins.powersave_bias) {
- __cpufreq_driver_target(policy, freq_next,
- CPUFREQ_RELATION_L);
- } else {
- int freq = powersave_bias_target(policy, freq_next,
- CPUFREQ_RELATION_L);
- __cpufreq_driver_target(policy, freq,
- CPUFREQ_RELATION_L);
- }
- }
-}
-
-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;
- int sample_type = dbs_info->sample_type;
-
- int delay;
-
- mutex_lock(&dbs_info->timer_mutex);
-
- /* Common NORMAL_SAMPLE setup */
- dbs_info->sample_type = DBS_NORMAL_SAMPLE;
- if (!dbs_tuners_ins.powersave_bias ||
- sample_type == DBS_NORMAL_SAMPLE) {
- dbs_check_cpu(dbs_info);
- if (dbs_info->freq_lo) {
- /* Setup timer for SUB_SAMPLE */
- dbs_info->sample_type = DBS_SUB_SAMPLE;
- delay = dbs_info->freq_hi_jiffies;
- } else {
- /* We want all CPUs to do sampling nearly on
- * same jiffy
- */
- delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate
- * dbs_info->rate_mult);
-
- if (num_online_cpus() > 1)
- delay -= jiffies % delay;
- }
- } else {
- __cpufreq_driver_target(dbs_info->cur_policy,
- dbs_info->freq_lo, CPUFREQ_RELATION_H);
- delay = dbs_info->freq_lo_jiffies;
- }
- 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);
-
- if (num_online_cpus() > 1)
- delay -= jiffies % delay;
-
- dbs_info->sample_type = DBS_NORMAL_SAMPLE;
- 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)
-{
- cancel_delayed_work_sync(&dbs_info->work);
-}
-
-/*
- * Not all CPUs want IO time to be accounted as busy; this dependson how
- * efficient idling at a higher frequency/voltage is.
- * Pavel Machek says this is not so for various generations of AMD and old
- * Intel systems.
- * Mike Chan (androidlcom) calis this is also not true for ARM.
- * Because of this, whitelist specific known (series) of CPUs by default, and
- * leave all others up to the user.
- */
-static int should_io_be_busy(void)
-{
-#if defined(CONFIG_X86)
- /*
- * For Intel, Core 2 (model 15) andl later have an efficient idle.
- */
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
- boot_cpu_data.x86 == 6 &&
- boot_cpu_data.x86_model >= 15)
- return 1;
-#endif
- return 0;
-}
-
-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(od_cpu_dbs_info, cpu);
-
- switch (event) {
- case CPUFREQ_GOV_START:
- if ((!cpu_online(cpu)) || (!policy->cur))
- return -EINVAL;
-
- mutex_lock(&dbs_mutex);
-
- dbs_enable++;
- for_each_cpu(j, policy->cpus) {
- struct cpu_dbs_info_s *j_dbs_info;
- j_dbs_info = &per_cpu(od_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->cpu = cpu;
- this_dbs_info->rate_mult = 1;
- ondemand_powersave_bias_init_cpu(cpu);
- /*
- * Start the timerschedule work, when this governor
- * is used for first time
- */
- if (dbs_enable == 1) {
- unsigned int latency;
-
- rc = sysfs_create_group(cpufreq_global_kobject,
- &dbs_attr_group);
- if (rc) {
- mutex_unlock(&dbs_mutex);
- return rc;
- }
-
- /* policy latency is in nS. Convert it to uS first */
- latency = policy->cpuinfo.transition_latency / 1000;
- if (latency == 0)
- latency = 1;
- /* 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);
- dbs_tuners_ins.io_is_busy = should_io_be_busy();
- }
- mutex_unlock(&dbs_mutex);
-
- mutex_init(&this_dbs_info->timer_mutex);
- dbs_timer_init(this_dbs_info);
- break;
-
- case CPUFREQ_GOV_STOP:
- dbs_timer_exit(this_dbs_info);
-
- mutex_lock(&dbs_mutex);
- mutex_destroy(&this_dbs_info->timer_mutex);
- dbs_enable--;
- 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;
-}
-
-static int __init cpufreq_gov_dbs_init(void)
-{
- u64 idle_time;
- int cpu = get_cpu();
-
- idle_time = get_cpu_idle_time_us(cpu, NULL);
- put_cpu();
- if (idle_time != -1ULL) {
- /* Idle micro accounting is supported. Use finer thresholds */
- dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD;
- dbs_tuners_ins.down_differential =
- MICRO_FREQUENCY_DOWN_DIFFERENTIAL;
- /*
- * In nohz/micro accounting case we set the minimum frequency
- * not depending on HZ, but fixed (very low). The deferred
- * timer might skip some samples if idle/sleeping as needed.
- */
- min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE;
- } else {
- /* For correct statistics, we need 10 ticks for each measure */
- min_sampling_rate =
- MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10);
- }
-
- return cpufreq_register_governor(&cpufreq_gov_ondemand);
-}
-
-static void __exit cpufreq_gov_dbs_exit(void)
-{
- cpufreq_unregister_governor(&cpufreq_gov_ondemand);
-}
-
-
-MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>");
-MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>");
-MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for "
- "Low Latency Frequency Transition capable processors");
-MODULE_LICENSE("GPL");
-
-#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND
-fs_initcall(cpufreq_gov_dbs_init);
-#else
-module_init(cpufreq_gov_dbs_init);
-#endif
-module_exit(cpufreq_gov_dbs_exit);