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/*
* drivers/cpufreq/cpufreq_pegasusq.c
*
* Copyright (C) 2011 Samsung Electronics co. ltd
* ByungChang Cha <bc.cha@samsung.com>
*
* Based on ondemand governor
* 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/cpumask.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>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/reboot.h>

#ifdef CONFIG_HAS_EARLYSUSPEND
#include <linux/earlysuspend.h>
#endif
#define EARLYSUSPEND_HOTPLUGLOCK 1

/*
* runqueue average
*/

#ifndef CONFIG_CPU_EXYNOS4210
#define RQ_AVG_TIMER_RATE 10
#else
#define RQ_AVG_TIMER_RATE 20
#endif

struct runqueue_data {
unsigned int nr_run_avg;
unsigned int update_rate;
int64_t last_time;
int64_t total_time;
struct delayed_work work;
struct workqueue_struct *nr_run_wq;
spinlock_t lock;
};

static struct runqueue_data *rq_data;
static void rq_work_fn(struct work_struct *work);

static void start_rq_work(void)
{
rq_data->nr_run_avg = 0;
rq_data->last_time = 0;
rq_data->total_time = 0;
if (rq_data->nr_run_wq == NULL)
rq_data->nr_run_wq =
create_singlethread_workqueue("nr_run_avg");

queue_delayed_work(rq_data->nr_run_wq, &rq_data->work,
msecs_to_jiffies(rq_data->update_rate));
return;
}

static void stop_rq_work(void)
{
if (rq_data->nr_run_wq)
cancel_delayed_work(&rq_data->work);
return;
}

static int __init init_rq_avg(void)
{
rq_data = kzalloc(sizeof(struct runqueue_data), GFP_KERNEL);
if (rq_data == NULL) {
pr_err("%s cannot allocate memory\n", __func__);
return -ENOMEM;
}
spin_lock_init(&rq_data->lock);
rq_data->update_rate = RQ_AVG_TIMER_RATE;
INIT_DELAYED_WORK_DEFERRABLE(&rq_data->work, rq_work_fn);

return 0;
}

static void rq_work_fn(struct work_struct *work)
{
int64_t time_diff = 0;
int64_t nr_run = 0;
unsigned long flags = 0;
int64_t cur_time = ktime_to_ns(ktime_get());

spin_lock_irqsave(&rq_data->lock, flags);

if (rq_data->last_time == 0)
rq_data->last_time = cur_time;
if (rq_data->nr_run_avg == 0)
rq_data->total_time = 0;

nr_run = nr_running() * 100;
time_diff = cur_time - rq_data->last_time;
do_div(time_diff, 1000 * 1000);

if (time_diff != 0 && rq_data->total_time != 0) {
nr_run = (nr_run * time_diff) +
(rq_data->nr_run_avg * rq_data->total_time);
do_div(nr_run, rq_data->total_time + time_diff);
}
rq_data->nr_run_avg = nr_run;
rq_data->total_time += time_diff;
rq_data->last_time = cur_time;

if (rq_data->update_rate != 0)
queue_delayed_work(rq_data->nr_run_wq, &rq_data->work,
msecs_to_jiffies(rq_data->update_rate));

spin_unlock_irqrestore(&rq_data->lock, flags);
}

static unsigned int get_nr_run_avg(void)
{
unsigned int nr_run_avg;
unsigned long flags = 0;

spin_lock_irqsave(&rq_data->lock, flags);
nr_run_avg = rq_data->nr_run_avg;
rq_data->nr_run_avg = 0;
spin_unlock_irqrestore(&rq_data->lock, flags);

return nr_run_avg;
}


/*
* dbs is used in this file as a shortform for demandbased switching
* It helps to keep variable names smaller, simpler
*/

#define DEF_SAMPLING_DOWN_FACTOR (2)
#define MAX_SAMPLING_DOWN_FACTOR (100000)
#define DEF_FREQUENCY_DOWN_DIFFERENTIAL (5)
#define DEF_FREQUENCY_UP_THRESHOLD (85)

/* for multiple freq_step */
#define DEF_UP_THRESHOLD_DIFF (5)

#define DEF_FREQUENCY_MIN_SAMPLE_RATE (10000)
#define MIN_FREQUENCY_UP_THRESHOLD (11)
#define MAX_FREQUENCY_UP_THRESHOLD (100)
#define DEF_SAMPLING_RATE (50000)
#define MIN_SAMPLING_RATE (10000)
#define MAX_HOTPLUG_RATE (40u)

#define DEF_MAX_CPU_LOCK (0)
#define DEF_MIN_CPU_LOCK (0)
#define DEF_CPU_UP_FREQ (500000)
#define DEF_CPU_DOWN_FREQ (200000)
#define DEF_UP_NR_CPUS (1)
#define DEF_CPU_UP_RATE (10)
#define DEF_CPU_DOWN_RATE (20)
#define DEF_FREQ_STEP (37)
/* for multiple freq_step */
#define DEF_FREQ_STEP_DEC (13)

#define DEF_START_DELAY (0)

#define UP_THRESHOLD_AT_MIN_FREQ (40)
#define FREQ_FOR_RESPONSIVENESS (400000)
/* for fast decrease */
#define FREQ_FOR_FAST_DOWN (1200000)
#define UP_THRESHOLD_AT_FAST_DOWN (95)

#define HOTPLUG_DOWN_INDEX (0)
#define HOTPLUG_UP_INDEX (1)

#ifdef CONFIG_MACH_MIDAS
static int hotplug_rq[4][2] = {
{0, 100}, {100, 200}, {200, 300}, {300, 0}
};

static int hotplug_freq[4][2] = {
{0, 500000},
{200000, 500000},
{200000, 500000},
{200000, 0}
};
#else
static int hotplug_rq[4][2] = {
{0, 100}, {100, 200}, {200, 300}, {300, 0}
};

static int hotplug_freq[4][2] = {
{0, 500000},
{200000, 500000},
{200000, 500000},
{200000, 0}
};
#endif

static unsigned int min_sampling_rate;

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_PEGASUSQ
static
#endif
struct cpufreq_governor cpufreq_gov_pegasusq = {
.name = "pegasusq",
.governor = cpufreq_governor_dbs,
.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 work_struct up_work;
struct work_struct down_work;
struct cpufreq_frequency_table *freq_table;
unsigned int rate_mult;
int cpu;
/*
* 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);

struct workqueue_struct *dvfs_workqueue;

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 io_is_busy;
/* pegasusq tuners */
unsigned int freq_step;
unsigned int cpu_up_rate;
unsigned int cpu_down_rate;
unsigned int cpu_up_freq;
unsigned int cpu_down_freq;
unsigned int up_nr_cpus;
unsigned int max_cpu_lock;
unsigned int min_cpu_lock;
atomic_t hotplug_lock;
unsigned int dvfs_debug;
unsigned int max_freq;
unsigned int min_freq;
#ifdef CONFIG_HAS_EARLYSUSPEND
int early_suspend;
#endif
unsigned int up_threshold_at_min_freq;
unsigned int freq_for_responsiveness;
} 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,
.freq_step = DEF_FREQ_STEP,
.cpu_up_rate = DEF_CPU_UP_RATE,
.cpu_down_rate = DEF_CPU_DOWN_RATE,
.cpu_up_freq = DEF_CPU_UP_FREQ,
.cpu_down_freq = DEF_CPU_DOWN_FREQ,
.up_nr_cpus = DEF_UP_NR_CPUS,
.max_cpu_lock = DEF_MAX_CPU_LOCK,
.min_cpu_lock = DEF_MIN_CPU_LOCK,
.hotplug_lock = ATOMIC_INIT(0),
.dvfs_debug = 0,
#ifdef CONFIG_HAS_EARLYSUSPEND
.early_suspend = -1,
#endif
.up_threshold_at_min_freq = UP_THRESHOLD_AT_MIN_FREQ,
.freq_for_responsiveness = FREQ_FOR_RESPONSIVENESS,
};


/*
* CPU hotplug lock interface
*/

static atomic_t g_hotplug_count = ATOMIC_INIT(0);
static atomic_t g_hotplug_lock = ATOMIC_INIT(0);

static void apply_hotplug_lock(void)
{
int online, possible, lock, flag;
struct work_struct *work;
struct cpu_dbs_info_s *dbs_info;

/* do turn_on/off cpus */
dbs_info = &per_cpu(od_cpu_dbs_info, 0); /* from CPU0 */
online = num_online_cpus();
possible = num_possible_cpus();
lock = atomic_read(&g_hotplug_lock);
flag = lock - online;

if (flag == 0)
return;

work = flag > 0 ? &dbs_info->up_work : &dbs_info->down_work;

pr_debug("%s online %d possible %d lock %d flag %d %d\n",
__func__, online, possible, lock, flag, (int)abs(flag));

queue_work_on(dbs_info->cpu, dvfs_workqueue, work);
}

int cpufreq_pegasusq_cpu_lock(int num_core)
{
int prev_lock;

if (num_core < 1 || num_core > num_possible_cpus())
return -EINVAL;

prev_lock = atomic_read(&g_hotplug_lock);

if (prev_lock != 0 && prev_lock < num_core)
return -EINVAL;
else if (prev_lock == num_core)
atomic_inc(&g_hotplug_count);

atomic_set(&g_hotplug_lock, num_core);
atomic_set(&g_hotplug_count, 1);
apply_hotplug_lock();

return 0;
}

int cpufreq_pegasusq_cpu_unlock(int num_core)
{
int prev_lock = atomic_read(&g_hotplug_lock);

if (prev_lock < num_core)
return 0;
else if (prev_lock == num_core)
atomic_dec(&g_hotplug_count);

if (atomic_read(&g_hotplug_count) == 0)
atomic_set(&g_hotplug_lock, 0);

return 0;
}

void cpufreq_pegasusq_min_cpu_lock(unsigned int num_core)
{
int online, flag;
struct cpu_dbs_info_s *dbs_info;

dbs_tuners_ins.min_cpu_lock = min(num_core, num_possible_cpus());

dbs_info = &per_cpu(od_cpu_dbs_info, 0); /* from CPU0 */
online = num_online_cpus();
flag = (int)num_core - online;
if (flag <= 0)
return;
queue_work_on(dbs_info->cpu, dvfs_workqueue, &dbs_info->up_work);
}

void cpufreq_pegasusq_min_cpu_unlock(void)
{
int online, lock, flag;
struct cpu_dbs_info_s *dbs_info;

dbs_tuners_ins.min_cpu_lock = 0;

dbs_info = &per_cpu(od_cpu_dbs_info, 0); /* from CPU0 */
online = num_online_cpus();
lock = atomic_read(&g_hotplug_lock);
if (lock == 0)
return;
flag = lock - online;
if (flag >= 0)
return;
queue_work_on(dbs_info->cpu, dvfs_workqueue, &dbs_info->down_work);
}

/*
* History of CPU usage
*/
struct cpu_usage {
unsigned int freq;
unsigned int load[NR_CPUS];
unsigned int rq_avg;
unsigned int avg_load;
};

struct cpu_usage_history {
struct cpu_usage usage[MAX_HOTPLUG_RATE];
unsigned int num_hist;
};

struct cpu_usage_history *hotplug_history;

static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
cputime64_t *wall)
{
cputime64_t idle_time;
cputime64_t cur_wall_time;
cputime64_t busy_time;

cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
kstat_cpu(cpu).cpustat.system);

busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice);

idle_time = cputime64_sub(cur_wall_time, busy_time);
if (wall)
*wall = (cputime64_t)jiffies_to_usecs(cur_wall_time);

return (cputime64_t)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, wall);

if (idle_time == -1ULL)
return get_cpu_idle_time_jiffy(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;
}

/************************** 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_pegasusq 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(down_differential, down_differential);
show_one(freq_step, freq_step);
show_one(cpu_up_rate, cpu_up_rate);
show_one(cpu_down_rate, cpu_down_rate);
show_one(cpu_up_freq, cpu_up_freq);
show_one(cpu_down_freq, cpu_down_freq);
show_one(up_nr_cpus, up_nr_cpus);
show_one(max_cpu_lock, max_cpu_lock);
show_one(min_cpu_lock, min_cpu_lock);
show_one(dvfs_debug, dvfs_debug);
show_one(up_threshold_at_min_freq, up_threshold_at_min_freq);
show_one(freq_for_responsiveness, freq_for_responsiveness);
static ssize_t show_hotplug_lock(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", atomic_read(&g_hotplug_lock));
}

#define show_hotplug_param(file_name, num_core, up_down) \
static ssize_t show_##file_name##_##num_core##_##up_down \
(struct kobject *kobj, struct attribute *attr, char *buf) \
{ \
return sprintf(buf, "%u\n", file_name[num_core - 1][up_down]); \
}

#define store_hotplug_param(file_name, num_core, up_down) \
static ssize_t store_##file_name##_##num_core##_##up_down \
(struct kobject *kobj, struct attribute *attr, \
const char *buf, size_t count) \
{ \
unsigned int input; \
int ret; \
ret = sscanf(buf, "%u", &input); \
if (ret != 1) \
return -EINVAL; \
file_name[num_core - 1][up_down] = input; \
return count; \
}

show_hotplug_param(hotplug_freq, 1, 1);
show_hotplug_param(hotplug_freq, 2, 0);
#ifndef CONFIG_CPU_EXYNOS4210
show_hotplug_param(hotplug_freq, 2, 1);
show_hotplug_param(hotplug_freq, 3, 0);
show_hotplug_param(hotplug_freq, 3, 1);
show_hotplug_param(hotplug_freq, 4, 0);
#endif

show_hotplug_param(hotplug_rq, 1, 1);
show_hotplug_param(hotplug_rq, 2, 0);
#ifndef CONFIG_CPU_EXYNOS4210
show_hotplug_param(hotplug_rq, 2, 1);
show_hotplug_param(hotplug_rq, 3, 0);
show_hotplug_param(hotplug_rq, 3, 1);
show_hotplug_param(hotplug_rq, 4, 0);
#endif

store_hotplug_param(hotplug_freq, 1, 1);
store_hotplug_param(hotplug_freq, 2, 0);
#ifndef CONFIG_CPU_EXYNOS4210
store_hotplug_param(hotplug_freq, 2, 1);
store_hotplug_param(hotplug_freq, 3, 0);
store_hotplug_param(hotplug_freq, 3, 1);
store_hotplug_param(hotplug_freq, 4, 0);
#endif

store_hotplug_param(hotplug_rq, 1, 1);
store_hotplug_param(hotplug_rq, 2, 0);
#ifndef CONFIG_CPU_EXYNOS4210
store_hotplug_param(hotplug_rq, 2, 1);
store_hotplug_param(hotplug_rq, 3, 0);
store_hotplug_param(hotplug_rq, 3, 1);
store_hotplug_param(hotplug_rq, 4, 0);
#endif

define_one_global_rw(hotplug_freq_1_1);
define_one_global_rw(hotplug_freq_2_0);
#ifndef CONFIG_CPU_EXYNOS4210
define_one_global_rw(hotplug_freq_2_1);
define_one_global_rw(hotplug_freq_3_0);
define_one_global_rw(hotplug_freq_3_1);
define_one_global_rw(hotplug_freq_4_0);
#endif

define_one_global_rw(hotplug_rq_1_1);
define_one_global_rw(hotplug_rq_2_0);
#ifndef CONFIG_CPU_EXYNOS4210
define_one_global_rw(hotplug_rq_2_1);
define_one_global_rw(hotplug_rq_3_0);
define_one_global_rw(hotplug_rq_3_1);
define_one_global_rw(hotplug_rq_4_0);
#endif

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_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 = kstat_cpu(j).cpustat.nice;
}
return count;
}

static ssize_t store_down_differential(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.down_differential = min(input, 100u);
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;
dbs_tuners_ins.freq_step = min(input, 100u);
return count;
}

static ssize_t store_cpu_up_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.cpu_up_rate = min(input, MAX_HOTPLUG_RATE);
return count;
}

static ssize_t store_cpu_down_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.cpu_down_rate = min(input, MAX_HOTPLUG_RATE);
return count;
}

static ssize_t store_cpu_up_freq(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.cpu_up_freq = min(input, dbs_tuners_ins.max_freq);
return count;
}

static ssize_t store_cpu_down_freq(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.cpu_down_freq = max(input, dbs_tuners_ins.min_freq);
return count;
}

static ssize_t store_up_nr_cpus(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.up_nr_cpus = min(input, num_possible_cpus());
return count;
}

static ssize_t store_max_cpu_lock(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.max_cpu_lock = min(input, num_possible_cpus());
return count;
}

static ssize_t store_min_cpu_lock(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 == 0)
cpufreq_pegasusq_min_cpu_unlock();
else
cpufreq_pegasusq_min_cpu_lock(input);
return count;
}

static ssize_t store_hotplug_lock(struct kobject *a, struct attribute *b,
const char *buf, size_t count)
{
unsigned int input;
int ret;
int prev_lock;

ret = sscanf(buf, "%u", &input);
if (ret != 1)
return -EINVAL;
input = min(input, num_possible_cpus());
prev_lock = atomic_read(&dbs_tuners_ins.hotplug_lock);

if (prev_lock)
cpufreq_pegasusq_cpu_unlock(prev_lock);

if (input == 0) {
atomic_set(&dbs_tuners_ins.hotplug_lock, 0);
return count;
}

ret = cpufreq_pegasusq_cpu_lock(input);
if (ret) {
printk(KERN_ERR "[HOTPLUG] already locked with smaller value %d < %d\n",
atomic_read(&g_hotplug_lock), input);
return ret;
}

atomic_set(&dbs_tuners_ins.hotplug_lock, input);

return count;
}

static ssize_t store_dvfs_debug(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.dvfs_debug = input > 0;
return count;
}

static ssize_t store_up_threshold_at_min_freq(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_at_min_freq = input;
return count;
}

static ssize_t store_freq_for_responsiveness(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.freq_for_responsiveness = input;
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(down_differential);
define_one_global_rw(freq_step);
define_one_global_rw(cpu_up_rate);
define_one_global_rw(cpu_down_rate);
define_one_global_rw(cpu_up_freq);
define_one_global_rw(cpu_down_freq);
define_one_global_rw(up_nr_cpus);
define_one_global_rw(max_cpu_lock);
define_one_global_rw(min_cpu_lock);
define_one_global_rw(hotplug_lock);
define_one_global_rw(dvfs_debug);
define_one_global_rw(up_threshold_at_min_freq);
define_one_global_rw(freq_for_responsiveness);

static struct attribute *dbs_attributes[] = {
&sampling_rate_min.attr,
&sampling_rate.attr,
&up_threshold.attr,
&sampling_down_factor.attr,
&ignore_nice_load.attr,
&io_is_busy.attr,
&down_differential.attr,
&freq_step.attr,
&cpu_up_rate.attr,
&cpu_down_rate.attr,
&cpu_up_freq.attr,
&cpu_down_freq.attr,
&up_nr_cpus.attr,
/* priority: hotplug_lock > max_cpu_lock > min_cpu_lock
Exception: hotplug_lock on early_suspend uses min_cpu_lock */
&max_cpu_lock.attr,
&min_cpu_lock.attr,
&hotplug_lock.attr,
&dvfs_debug.attr,
&hotplug_freq_1_1.attr,
&hotplug_freq_2_0.attr,
#ifndef CONFIG_CPU_EXYNOS4210
&hotplug_freq_2_1.attr,
&hotplug_freq_3_0.attr,
&hotplug_freq_3_1.attr,
&hotplug_freq_4_0.attr,
#endif
&hotplug_rq_1_1.attr,
&hotplug_rq_2_0.attr,
#ifndef CONFIG_CPU_EXYNOS4210
&hotplug_rq_2_1.attr,
&hotplug_rq_3_0.attr,
&hotplug_rq_3_1.attr,
&hotplug_rq_4_0.attr,
#endif
&up_threshold_at_min_freq.attr,
&freq_for_responsiveness.attr,
NULL
};

static struct attribute_group dbs_attr_group = {
.attrs = dbs_attributes,
.name = "pegasusq",
};

/************************** sysfs end ************************/

static void cpu_up_work(struct work_struct *work)
{
int cpu;
int online = num_online_cpus();
int nr_up = dbs_tuners_ins.up_nr_cpus;
int min_cpu_lock = dbs_tuners_ins.min_cpu_lock;
int hotplug_lock = atomic_read(&g_hotplug_lock);

if (hotplug_lock && min_cpu_lock)
nr_up = max(hotplug_lock, min_cpu_lock) - online;
else if (hotplug_lock)
nr_up = hotplug_lock - online;
else if (min_cpu_lock)
nr_up = max(nr_up, min_cpu_lock - online);

if (online == 1) {
printk(KERN_ERR "CPU_UP 3\n");
cpu_up(num_possible_cpus() - 1);
nr_up -= 1;
}

for_each_cpu_not(cpu, cpu_online_mask) {
if (nr_up-- == 0)
break;
if (cpu == 0)
continue;
printk(KERN_ERR "CPU_UP %d\n", cpu);
cpu_up(cpu);
}
}

static void cpu_down_work(struct work_struct *work)
{
int cpu;
int online = num_online_cpus();
int nr_down = 1;
int hotplug_lock = atomic_read(&g_hotplug_lock);

if (hotplug_lock)
nr_down = online - hotplug_lock;

for_each_online_cpu(cpu) {
if (cpu == 0)
continue;
printk(KERN_ERR "CPU_DOWN %d\n", cpu);
cpu_down(cpu);
if (--nr_down == 0)
break;
}
}

static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq)
{
#ifndef CONFIG_ARCH_EXYNOS4
if (p->cur == p->max)
return;
#endif

__cpufreq_driver_target(p, freq, CPUFREQ_RELATION_L);
}

/*
* print hotplug debugging info.
* which 1 : UP, 0 : DOWN
*/
static void debug_hotplug_check(int which, int rq_avg, int freq,
struct cpu_usage *usage)
{
int cpu;
printk(KERN_ERR "CHECK %s rq %d.%02d freq %d [", which ? "up" : "down",
rq_avg / 100, rq_avg % 100, freq);
for_each_online_cpu(cpu) {
printk(KERN_ERR "(%d, %d), ", cpu, usage->load[cpu]);
}
printk(KERN_ERR "]\n");
}

static int check_up(void)
{
int num_hist = hotplug_history->num_hist;
struct cpu_usage *usage;
int freq, rq_avg;
int avg_load;
int i;
int up_rate = dbs_tuners_ins.cpu_up_rate;
int up_freq, up_rq;
int min_freq = INT_MAX;
int min_rq_avg = INT_MAX;
int min_avg_load = INT_MAX;
int online;
int hotplug_lock = atomic_read(&g_hotplug_lock);

if (hotplug_lock > 0)
return 0;

online = num_online_cpus();
up_freq = hotplug_freq[online - 1][HOTPLUG_UP_INDEX];
up_rq = hotplug_rq[online - 1][HOTPLUG_UP_INDEX];

if (online == num_possible_cpus())
return 0;

if (dbs_tuners_ins.max_cpu_lock != 0
&& online >= dbs_tuners_ins.max_cpu_lock)
return 0;

if (dbs_tuners_ins.min_cpu_lock != 0
&& online < dbs_tuners_ins.min_cpu_lock)
return 1;

if (num_hist == 0 || num_hist % up_rate)
return 0;

for (i = num_hist - 1; i >= num_hist - up_rate; --i) {
usage = &hotplug_history->usage[i];

freq = usage->freq;
rq_avg = usage->rq_avg;
avg_load = usage->avg_load;

min_freq = min(min_freq, freq);
min_rq_avg = min(min_rq_avg, rq_avg);
min_avg_load = min(min_avg_load, avg_load);

if (dbs_tuners_ins.dvfs_debug)
debug_hotplug_check(1, rq_avg, freq, usage);
}

if (min_freq >= up_freq && min_rq_avg > up_rq) {
if (online >= 2) {
if (min_avg_load < 65)
return 0;
}
printk(KERN_ERR "[HOTPLUG IN] %s %d>=%d && %d>%d\n",
__func__, min_freq, up_freq, min_rq_avg, up_rq);
hotplug_history->num_hist = 0;
return 1;
}
return 0;
}

static int check_down(void)
{
int num_hist = hotplug_history->num_hist;
struct cpu_usage *usage;
int freq, rq_avg;
int avg_load;
int i;
int down_rate = dbs_tuners_ins.cpu_down_rate;
int down_freq, down_rq;
int max_freq = 0;
int max_rq_avg = 0;
int max_avg_load = 0;
int online;
int hotplug_lock = atomic_read(&g_hotplug_lock);

if (hotplug_lock > 0)
return 0;

online = num_online_cpus();
down_freq = hotplug_freq[online - 1][HOTPLUG_DOWN_INDEX];
down_rq = hotplug_rq[online - 1][HOTPLUG_DOWN_INDEX];

if (online == 1)
return 0;

if (dbs_tuners_ins.max_cpu_lock != 0
&& online > dbs_tuners_ins.max_cpu_lock)
return 1;

if (dbs_tuners_ins.min_cpu_lock != 0
&& online <= dbs_tuners_ins.min_cpu_lock)
return 0;

if (num_hist == 0 || num_hist % down_rate)
return 0;

for (i = num_hist - 1; i >= num_hist - down_rate; --i) {
usage = &hotplug_history->usage[i];

freq = usage->freq;
rq_avg = usage->rq_avg;
avg_load = usage->avg_load;

max_freq = max(max_freq, freq);
max_rq_avg = max(max_rq_avg, rq_avg);
max_avg_load = max(max_avg_load, avg_load);

if (dbs_tuners_ins.dvfs_debug)
debug_hotplug_check(0, rq_avg, freq, usage);
}

if ((max_freq <= down_freq && max_rq_avg <= down_rq)
|| (online >= 3 && max_avg_load < 30)) {
printk(KERN_ERR "[HOTPLUG OUT] %s %d<=%d && %d<%d\n",
__func__, max_freq, down_freq, max_rq_avg, down_rq);
hotplug_history->num_hist = 0;
return 1;
}

return 0;
}

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;
int num_hist = hotplug_history->num_hist;
int max_hotplug_rate = max(dbs_tuners_ins.cpu_up_rate,
dbs_tuners_ins.cpu_down_rate);
int up_threshold = dbs_tuners_ins.up_threshold;

/* add total_load, avg_load to get average load */
unsigned int total_load = 0;
unsigned int avg_load = 0;
int load_each[4] = {-1, -1, -1, -1};
int rq_avg = 0;
policy = this_dbs_info->cur_policy;

hotplug_history->usage[num_hist].freq = policy->cur;
hotplug_history->usage[num_hist].rq_avg = get_nr_run_avg();

/* add total_load, avg_load to get average load */
rq_avg = hotplug_history->usage[num_hist].rq_avg;

++hotplug_history->num_hist;

/* 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;
cputime64_t prev_wall_time, prev_idle_time, prev_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);
prev_wall_time = j_dbs_info->prev_cpu_wall;
prev_idle_time = j_dbs_info->prev_cpu_idle;
prev_iowait_time = j_dbs_info->prev_cpu_iowait;

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) cputime64_sub(cur_wall_time,
prev_wall_time);
j_dbs_info->prev_cpu_wall = cur_wall_time;

idle_time = (unsigned int) cputime64_sub(cur_idle_time,
prev_idle_time);
j_dbs_info->prev_cpu_idle = cur_idle_time;

iowait_time = (unsigned int) cputime64_sub(cur_iowait_time,
prev_iowait_time);
j_dbs_info->prev_cpu_iowait = cur_iowait_time;

if (dbs_tuners_ins.ignore_nice) {
cputime64_t cur_nice;
unsigned long cur_nice_jiffies;

cur_nice = cputime64_sub(kstat_cpu(j).cpustat.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 = kstat_cpu(j).cpustat.nice;
idle_time += jiffies_to_usecs(cur_nice_jiffies);
}

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;

/* keep load of each CPUs and combined load across all CPUs */
if (cpu_online(j))
load_each[j] = load;
total_load += load;

hotplug_history->usage[num_hist].load[j] = load;

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;
}
/* calculate the average load across all related CPUs */
avg_load = total_load / num_online_cpus();
hotplug_history->usage[num_hist].avg_load = avg_load;


/* Check for CPU hotplug */
if (check_up()) {
queue_work_on(this_dbs_info->cpu, dvfs_workqueue,
&this_dbs_info->up_work);
} else if (check_down()) {
queue_work_on(this_dbs_info->cpu, dvfs_workqueue,
&this_dbs_info->down_work);
}
if (hotplug_history->num_hist == max_hotplug_rate)
hotplug_history->num_hist = 0;

/* Check for frequency increase */
if (policy->cur < dbs_tuners_ins.freq_for_responsiveness)
up_threshold = dbs_tuners_ins.up_threshold_at_min_freq;
/* for fast frequency decrease */
else
up_threshold = dbs_tuners_ins.up_threshold;

if (max_load_freq > up_threshold * policy->cur) {
/* for multiple freq_step */
int inc = policy->max * (dbs_tuners_ins.freq_step
- DEF_FREQ_STEP_DEC * 2) / 100;
int target = 0;

/* for multiple freq_step */
if (max_load_freq > (up_threshold + DEF_UP_THRESHOLD_DIFF * 2)
* policy->cur)
inc = policy->max * dbs_tuners_ins.freq_step / 100;
else if (max_load_freq > (up_threshold + DEF_UP_THRESHOLD_DIFF)
* policy->cur)
inc = policy->max * (dbs_tuners_ins.freq_step
- DEF_FREQ_STEP_DEC) / 100;

target = min(policy->max, policy->cur + inc);

/* If switching to max speed, apply sampling_down_factor */
if (policy->cur < policy->max && target == policy->max)
this_dbs_info->rate_mult =
dbs_tuners_ins.sampling_down_factor;
dbs_freq_increase(policy, target);
return;
}

/* Check for frequency decrease */
#ifndef CONFIG_ARCH_EXYNOS4
/* if we cannot reduce the frequency anymore, break out early */
if (policy->cur == policy->min)
return;
#endif

/*
* 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 DOWN_DIFFERENTIAL points under
* the threshold.
*/
if (max_load_freq <
(dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) *
policy->cur) {
unsigned int freq_next;
unsigned int down_thres;

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;


down_thres = dbs_tuners_ins.up_threshold_at_min_freq
- dbs_tuners_ins.down_differential;

if (freq_next < dbs_tuners_ins.freq_for_responsiveness
&& (max_load_freq / freq_next) > down_thres)
freq_next = dbs_tuners_ins.freq_for_responsiveness;

if (policy->cur == freq_next)
return;

__cpufreq_driver_target(policy, freq_next,
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 delay;

mutex_lock(&dbs_info->timer_mutex);

dbs_check_cpu(dbs_info);
/* 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;

queue_delayed_work_on(cpu, dvfs_workqueue, &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(DEF_START_DELAY * 1000 * 1000
+ dbs_tuners_ins.sampling_rate);
if (num_online_cpus() > 1)
delay -= jiffies % delay;

INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer);
INIT_WORK(&dbs_info->up_work, cpu_up_work);
INIT_WORK(&dbs_info->down_work, cpu_down_work);

queue_delayed_work_on(dbs_info->cpu, dvfs_workqueue,
&dbs_info->work, delay + 2 * HZ);
}

static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
{
cancel_delayed_work_sync(&dbs_info->work);
cancel_work_sync(&dbs_info->up_work);
cancel_work_sync(&dbs_info->down_work);
}

static int pm_notifier_call(struct notifier_block *this,
unsigned long event, void *ptr)
{
static unsigned int prev_hotplug_lock;
switch (event) {
case PM_SUSPEND_PREPARE:
prev_hotplug_lock = atomic_read(&g_hotplug_lock);
atomic_set(&g_hotplug_lock, 1);
apply_hotplug_lock();
pr_debug("%s enter suspend\n", __func__);
return NOTIFY_OK;
case PM_POST_RESTORE:
case PM_POST_SUSPEND:
atomic_set(&g_hotplug_lock, prev_hotplug_lock);
if (prev_hotplug_lock)
apply_hotplug_lock();
prev_hotplug_lock = 0;
pr_debug("%s exit suspend\n", __func__);
return NOTIFY_OK;
}
return NOTIFY_DONE;
}

static struct notifier_block pm_notifier = {
.notifier_call = pm_notifier_call,
};

static int reboot_notifier_call(struct notifier_block *this,
unsigned long code, void *_cmd)
{
atomic_set(&g_hotplug_lock, 1);
return NOTIFY_DONE;
}

static struct notifier_block reboot_notifier = {
.notifier_call = reboot_notifier_call,
};

#ifdef CONFIG_HAS_EARLYSUSPEND
static struct early_suspend early_suspend;
unsigned int prev_freq_step;
unsigned int prev_sampling_rate;
static void cpufreq_pegasusq_early_suspend(struct early_suspend *h)
{
#if EARLYSUSPEND_HOTPLUGLOCK
dbs_tuners_ins.early_suspend =
atomic_read(&g_hotplug_lock);
#endif
prev_freq_step = dbs_tuners_ins.freq_step;
prev_sampling_rate = dbs_tuners_ins.sampling_rate;
dbs_tuners_ins.freq_step = 10;
dbs_tuners_ins.sampling_rate = 200000;
#if EARLYSUSPEND_HOTPLUGLOCK
atomic_set(&g_hotplug_lock,
(dbs_tuners_ins.min_cpu_lock) ? dbs_tuners_ins.min_cpu_lock : 1);
apply_hotplug_lock();
stop_rq_work();
#endif
}
static void cpufreq_pegasusq_late_resume(struct early_suspend *h)
{
#if EARLYSUSPEND_HOTPLUGLOCK
atomic_set(&g_hotplug_lock, dbs_tuners_ins.early_suspend);
#endif
dbs_tuners_ins.early_suspend = -1;
dbs_tuners_ins.freq_step = prev_freq_step;
dbs_tuners_ins.sampling_rate = prev_sampling_rate;
#if EARLYSUSPEND_HOTPLUGLOCK
apply_hotplug_lock();
start_rq_work();
#endif
}
#endif

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;

dbs_tuners_ins.max_freq = policy->max;
dbs_tuners_ins.min_freq = policy->min;
hotplug_history->num_hist = 0;
start_rq_work();

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 =
kstat_cpu(j).cpustat.nice;
}
}
this_dbs_info->cpu = cpu;
this_dbs_info->rate_mult = 1;
/*
* Start the timerschedule work, when this governor
* is used for first time
*/
if (dbs_enable == 1) {
rc = sysfs_create_group(cpufreq_global_kobject,
&dbs_attr_group);
if (rc) {
mutex_unlock(&dbs_mutex);
return rc;
}

min_sampling_rate = MIN_SAMPLING_RATE;
dbs_tuners_ins.sampling_rate = DEF_SAMPLING_RATE;
dbs_tuners_ins.io_is_busy = 0;
}
mutex_unlock(&dbs_mutex);

register_reboot_notifier(&reboot_notifier);

mutex_init(&this_dbs_info->timer_mutex);
dbs_timer_init(this_dbs_info);

#if !EARLYSUSPEND_HOTPLUGLOCK
register_pm_notifier(&pm_notifier);
#endif
#ifdef CONFIG_HAS_EARLYSUSPEND
register_early_suspend(&early_suspend);
#endif
break;

case CPUFREQ_GOV_STOP:
#ifdef CONFIG_HAS_EARLYSUSPEND
unregister_early_suspend(&early_suspend);
#endif
#if !EARLYSUSPEND_HOTPLUGLOCK
unregister_pm_notifier(&pm_notifier);
#endif

dbs_timer_exit(this_dbs_info);

mutex_lock(&dbs_mutex);
mutex_destroy(&this_dbs_info->timer_mutex);

unregister_reboot_notifier(&reboot_notifier);

dbs_enable--;
mutex_unlock(&dbs_mutex);

stop_rq_work();

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)
{
int ret;

ret = init_rq_avg();
if (ret)
return ret;

hotplug_history = kzalloc(sizeof(struct cpu_usage_history), GFP_KERNEL);
if (!hotplug_history) {
pr_err("%s cannot create hotplug history array\n", __func__);
ret = -ENOMEM;
goto err_hist;
}

dvfs_workqueue = create_workqueue("kpegasusq");
if (!dvfs_workqueue) {
pr_err("%s cannot create workqueue\n", __func__);
ret = -ENOMEM;
goto err_queue;
}

ret = cpufreq_register_governor(&cpufreq_gov_pegasusq);
if (ret)
goto err_reg;

#ifdef CONFIG_HAS_EARLYSUSPEND
early_suspend.level = EARLY_SUSPEND_LEVEL_DISABLE_FB;
early_suspend.suspend = cpufreq_pegasusq_early_suspend;
early_suspend.resume = cpufreq_pegasusq_late_resume;
#endif

return ret;

err_reg:
destroy_workqueue(dvfs_workqueue);
err_queue:
kfree(hotplug_history);
err_hist:
kfree(rq_data);
return ret;
}

static void __exit cpufreq_gov_dbs_exit(void)
{
cpufreq_unregister_governor(&cpufreq_gov_pegasusq);
destroy_workqueue(dvfs_workqueue);
kfree(hotplug_history);
kfree(rq_data);
}

MODULE_AUTHOR("ByungChang Cha <bc.cha@samsung.com>");
MODULE_DESCRIPTION("'cpufreq_pegasusq' - A dynamic cpufreq/cpuhotplug governor");
MODULE_LICENSE("GPL");

#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PEGASUSQ
fs_initcall(cpufreq_gov_dbs_init);
#else
module_init(cpufreq_gov_dbs_init);
#endif
module_exit(cpufreq_gov_dbs_exit);
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