arch/arm/mach-msm/msm_mpdecision.c

 /* Copyright (c) 2012, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt)     "mpd %s: " fmt, __func__

#include <linux/cpumask.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <linux/kobject.h>
#include <linux/ktime.h>
#include <linux/hrtimer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/cpu.h>
#include <linux/stringify.h>
#include <linux/sched.h>
#include <linux/platform_device.h>
#include <linux/debugfs.h>
#include <linux/cpu_pm.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/sched.h>
#include <linux/rq_stats.h>
#include <asm/atomic.h>
#include <asm/page.h>
#include <mach/msm_dcvs.h>
#include <mach/msm_dcvs_scm.h>
#define CREATE_TRACE_POINTS
#include <trace/events/mpdcvs_trace.h>

#define DEFAULT_RQ_AVG_POLL_MS    (1)

struct mpd_attrib {
	struct kobj_attribute	enabled;
	struct kobj_attribute	rq_avg_poll_ms;
	struct kobj_attribute iowait_threshold_pct;

	struct kobj_attribute	em_win_size_min_us;
	struct kobj_attribute	em_win_size_max_us;
	struct kobj_attribute	em_max_util_pct;
	struct kobj_attribute	mp_em_rounding_point_min;
	struct kobj_attribute	mp_em_rounding_point_max;
	struct kobj_attribute	online_util_pct_min;
	struct kobj_attribute	online_util_pct_max;
	struct kobj_attribute	slack_time_min_us;
	struct kobj_attribute	slack_time_max_us;
	struct kobj_attribute	hp_up_max_ms;
	struct kobj_attribute	hp_up_ms;
	struct kobj_attribute	hp_up_count;
	struct kobj_attribute	hp_dw_max_ms;
	struct kobj_attribute	hp_dw_ms;
	struct kobj_attribute	hp_dw_count;
	struct attribute_group	attrib_group;
};

struct msm_mpd_scm_data {
	enum msm_dcvs_scm_event event;
	int			nr;
};

struct mpdecision {
	uint32_t			enabled;
	atomic_t			algo_cpu_mask;
	uint32_t			rq_avg_poll_ms;
	uint32_t			iowait_threshold_pct;
	ktime_t				next_update;
	uint32_t			slack_us;
	struct msm_mpd_algo_param	mp_param;
	struct mpd_attrib		attrib;
	struct mutex			lock;
	struct task_struct		*task;
	struct task_struct		*hptask;
	struct hrtimer			slack_timer;
	struct msm_mpd_scm_data		data;
	int				hpupdate;
	wait_queue_head_t		wait_q;
	wait_queue_head_t		wait_hpq;
};

struct hp_latency {
	int hp_up_max_ms;
	int hp_up_ms;
	int hp_up_count;
	int hp_dw_max_ms;
	int hp_dw_ms;
	int hp_dw_count;
};

static DEFINE_PER_CPU(struct hrtimer, rq_avg_poll_timer);
static DEFINE_SPINLOCK(rq_avg_lock);

enum {
	MSM_MPD_DEBUG_NOTIFIER = BIT(0),
	MSM_MPD_CORE_STATUS = BIT(1),
	MSM_MPD_SLACK_TIMER = BIT(2),
};

enum {
	HPUPDATE_WAITING = 0, /* we are waiting for cpumask update */
	HPUPDATE_SCHEDULED = 1, /* we are in the process of hotplugging */
	HPUPDATE_IN_PROGRESS = 2, /* we are in the process of hotplugging */
};

static int msm_mpd_enabled = 1;
module_param_named(enabled, msm_mpd_enabled, int, S_IRUGO | S_IWUSR | S_IWGRP);

static struct dentry *debugfs_base;
static struct mpdecision msm_mpd;

static struct hp_latency hp_latencies;

static unsigned long last_nr;
static int num_present_hundreds;

#define RQ_AVG_INSIGNIFICANT_BITS	3
static bool ok_to_update_tz(int nr, int last_nr)
{
	/*
	 * Exclude unnecessary TZ reports if run queue haven't changed much from
	 * the last reported value. The left shift by INSIGNIFICANT_BITS is to
	 * filter out small changes in the run queue average which won't cause
	 * a online cpu mask change. Also if the cpu online count does not match
	 * the count requested by TZ and we are not in the process of bringing
	 * cpus online as indicated by a HPUPDATE_IN_PROGRESS in msm_mpd.hpdata
	 */
	return
	(((nr >> RQ_AVG_INSIGNIFICANT_BITS)
				!= (last_nr >> RQ_AVG_INSIGNIFICANT_BITS))
	|| ((hweight32(atomic_read(&msm_mpd.algo_cpu_mask))
				!= num_online_cpus())
		&& (msm_mpd.hpupdate != HPUPDATE_IN_PROGRESS)));
}

static enum hrtimer_restart msm_mpd_rq_avg_poll_timer(struct hrtimer *timer)
{
	int nr, nr_iowait;
	ktime_t curr_time = ktime_get();
	unsigned long flags;
	int cpu = smp_processor_id();
	enum hrtimer_restart restart = HRTIMER_RESTART;

	spin_lock_irqsave(&rq_avg_lock, flags);
	/* If running on the wrong cpu, don't restart */
	if (&per_cpu(rq_avg_poll_timer, cpu) != timer)
		restart = HRTIMER_NORESTART;

	if (ktime_to_ns(ktime_sub(curr_time, msm_mpd.next_update)) < 0)
		goto out;

	msm_mpd.next_update = ktime_add_ns(curr_time,
			(msm_mpd.rq_avg_poll_ms * NSEC_PER_MSEC));

	sched_get_nr_running_avg(&nr, &nr_iowait);

	if ((nr_iowait >= msm_mpd.iowait_threshold_pct) && (nr < last_nr))
		nr = last_nr;

	if (nr > num_present_hundreds)
		nr = num_present_hundreds;

	trace_msm_mp_runq("nr_running", nr);

	if (ok_to_update_tz(nr, last_nr)) {
		hrtimer_try_to_cancel(&msm_mpd.slack_timer);
		msm_mpd.data.nr = nr;
		msm_mpd.data.event = MSM_DCVS_SCM_RUNQ_UPDATE;
		wake_up(&msm_mpd.wait_q);
		last_nr = nr;
	}

out:
	hrtimer_set_expires(timer, msm_mpd.next_update);
	spin_unlock_irqrestore(&rq_avg_lock, flags);
	/* set next expiration */
	return restart;
}

static void bring_up_cpu(int cpu)
{
	int cpu_action_time_ms;
	int time_taken_ms;
	int ret, ret1, ret2;

	cpu_action_time_ms = ktime_to_ms(ktime_get());
	ret = cpu_up(cpu);
	if (ret) {
		pr_debug("Error %d online core %d\n", ret, cpu);
	} else {
		time_taken_ms = ktime_to_ms(ktime_get()) - cpu_action_time_ms;
		if (time_taken_ms > hp_latencies.hp_up_max_ms)
			hp_latencies.hp_up_max_ms = time_taken_ms;
		hp_latencies.hp_up_ms += time_taken_ms;
		hp_latencies.hp_up_count++;
		ret = msm_dcvs_scm_event(
				CPU_OFFSET + cpu,
				MSM_DCVS_SCM_CORE_ONLINE,
				cpufreq_get(cpu),
				(uint32_t) time_taken_ms * USEC_PER_MSEC,
				&ret1, &ret2);
		if (ret)
			pr_err("Error sending hotplug scm event err=%d\n", ret);
	}
}

static void bring_down_cpu(int cpu)
{
	int cpu_action_time_ms;
	int time_taken_ms;
	int ret, ret1, ret2;

	BUG_ON(cpu == 0);
	cpu_action_time_ms = ktime_to_ms(ktime_get());
	ret = cpu_down(cpu);
	if (ret) {
		pr_debug("Error %d offline" "core %d\n", ret, cpu);
	} else {
		time_taken_ms = ktime_to_ms(ktime_get()) - cpu_action_time_ms;
		if (time_taken_ms > hp_latencies.hp_dw_max_ms)
			hp_latencies.hp_dw_max_ms = time_taken_ms;
		hp_latencies.hp_dw_ms += time_taken_ms;
		hp_latencies.hp_dw_count++;
		ret = msm_dcvs_scm_event(
				CPU_OFFSET + cpu,
				MSM_DCVS_SCM_CORE_OFFLINE,
				(uint32_t) time_taken_ms * USEC_PER_MSEC,
				0,
				&ret1, &ret2);
		if (ret)
			pr_err("Error sending hotplug scm event err=%d\n", ret);
	}
}

static int __ref msm_mpd_update_scm(enum msm_dcvs_scm_event event, int nr)
{
	int ret = 0;
	uint32_t req_cpu_mask = 0;
	uint32_t slack_us = 0;
	uint32_t param0 = 0;

	if (event == MSM_DCVS_SCM_RUNQ_UPDATE)
		param0 = nr;

	ret = msm_dcvs_scm_event(0, event, param0, 0,
				 &req_cpu_mask, &slack_us);

	if (ret) {
		pr_err("Error (%d) sending event %d, param %d\n", ret, event,
				param0);
		return ret;
	}

	trace_msm_mp_cpusonline("cpu_online_mp", req_cpu_mask);
	trace_msm_mp_slacktime("slack_time_mp", slack_us);
	msm_mpd.slack_us = slack_us;
	atomic_set(&msm_mpd.algo_cpu_mask, req_cpu_mask);
	msm_mpd.hpupdate = HPUPDATE_SCHEDULED;
	wake_up(&msm_mpd.wait_hpq);

	/* Start MP Decision slack timer */
	if (slack_us) {
		hrtimer_cancel(&msm_mpd.slack_timer);
		ret = hrtimer_start(&msm_mpd.slack_timer,
				ktime_set(0, slack_us * NSEC_PER_USEC),
				HRTIMER_MODE_REL_PINNED);
		if (ret)
			pr_err("Failed to register slack timer (%d) %d\n",
					slack_us, ret);
	}

	return ret;
}

static enum hrtimer_restart msm_mpd_slack_timer(struct hrtimer *timer)
{
	unsigned long flags;

	trace_printk("mpd:slack_timer_fired!\n");

	spin_lock_irqsave(&rq_avg_lock, flags);
	if (msm_mpd.data.event == MSM_DCVS_SCM_RUNQ_UPDATE)
		goto out;

	msm_mpd.data.nr = 0;
	msm_mpd.data.event = MSM_DCVS_SCM_MPD_QOS_TIMER_EXPIRED;
	wake_up(&msm_mpd.wait_q);
out:
	spin_unlock_irqrestore(&rq_avg_lock, flags);
	return HRTIMER_NORESTART;
}

static int msm_mpd_idle_notifier(struct notifier_block *self,
				 unsigned long cmd, void *v)
{
	int cpu = smp_processor_id();
	unsigned long flags;

	switch (cmd) {
	case CPU_PM_EXIT:
		spin_lock_irqsave(&rq_avg_lock, flags);
		hrtimer_start(&per_cpu(rq_avg_poll_timer, cpu),
			      msm_mpd.next_update,
			      HRTIMER_MODE_ABS_PINNED);
		spin_unlock_irqrestore(&rq_avg_lock, flags);
		break;
	case CPU_PM_ENTER:
		hrtimer_cancel(&per_cpu(rq_avg_poll_timer, cpu));
		break;
	default:
		break;
	}

	return NOTIFY_OK;
}

static int msm_mpd_hotplug_notifier(struct notifier_block *self,
				    unsigned long action, void *hcpu)
{
	int cpu = (int)hcpu;
	unsigned long flags;

	switch (action & (~CPU_TASKS_FROZEN)) {
	case CPU_STARTING:
		spin_lock_irqsave(&rq_avg_lock, flags);
		hrtimer_start(&per_cpu(rq_avg_poll_timer, cpu),
			      msm_mpd.next_update,
			      HRTIMER_MODE_ABS_PINNED);
		spin_unlock_irqrestore(&rq_avg_lock, flags);
		break;
	default:
		break;
	}

	return NOTIFY_OK;
}

static struct notifier_block msm_mpd_idle_nb = {
	.notifier_call = msm_mpd_idle_notifier,
};

static struct notifier_block msm_mpd_hotplug_nb = {
	.notifier_call = msm_mpd_hotplug_notifier,
};

static int __cpuinit msm_mpd_do_hotplug(void *data)
{
	int *event = (int *)data;
	int cpu;

	while (1) {
		wait_event(msm_mpd.wait_hpq, *event || kthread_should_stop());
		if (kthread_should_stop())
			break;

		msm_mpd.hpupdate = HPUPDATE_IN_PROGRESS;
		/*
		 * Bring online any offline cores, then offline any online
		 * cores.  Whenever a core is off/onlined restart the procedure
		 * in case a new core is desired to be brought online in the
		 * mean time.
		 */
restart:
		for_each_possible_cpu(cpu) {
			if ((atomic_read(&msm_mpd.algo_cpu_mask) & (1 << cpu))
				&& !cpu_online(cpu)) {
				bring_up_cpu(cpu);
				if (cpu_online(cpu))
					goto restart;
			}
		}

		for_each_possible_cpu(cpu) {
			if (!(atomic_read(&msm_mpd.algo_cpu_mask) & (1 << cpu))
				&& cpu_online(cpu)) {
				bring_down_cpu(cpu);
				if (!cpu_online(cpu))
					goto restart;
			}
		}
		msm_mpd.hpupdate = HPUPDATE_WAITING;
	}

	return 0;
}

static int msm_mpd_do_update_scm(void *data)
{
	struct msm_mpd_scm_data *scm_data = (struct msm_mpd_scm_data *)data;
	unsigned long flags;
	enum msm_dcvs_scm_event event;
	int nr;

	while (1) {
		wait_event(msm_mpd.wait_q,
			msm_mpd.data.event == MSM_DCVS_SCM_MPD_QOS_TIMER_EXPIRED
			|| msm_mpd.data.event == MSM_DCVS_SCM_RUNQ_UPDATE
			|| kthread_should_stop());

		if (kthread_should_stop())
			break;

		spin_lock_irqsave(&rq_avg_lock, flags);
		event = scm_data->event;
		nr = scm_data->nr;
		scm_data->event = 0;
		scm_data->nr = 0;
		spin_unlock_irqrestore(&rq_avg_lock, flags);

		msm_mpd_update_scm(event, nr);
	}
	return 0;
}

static int __ref msm_mpd_set_enabled(uint32_t enable)
{
	int ret = 0;
	int ret0 = 0;
	int ret1 = 0;
	int cpu;
	static uint32_t last_enable;

	enable = (enable > 0) ? 1 : 0;
	if (last_enable == enable)
		return ret;

	if (enable) {
		ret = msm_mpd_scm_set_algo_params(&msm_mpd.mp_param);
		if (ret) {
			pr_err("Error(%d): msm_mpd_scm_set_algo_params failed\n",
				ret);
			return ret;
		}
	}

	ret = msm_dcvs_scm_event(0, MSM_DCVS_SCM_MPD_ENABLE, enable, 0,
			&ret0, &ret1);
	if (ret) {
		pr_err("Error(%d) %s MP Decision\n",
				ret, (enable ? "enabling" : "disabling"));
	} else {
		last_enable = enable;
		last_nr = 0;
	}
	if (enable) {
		msm_mpd.next_update = ktime_add_ns(ktime_get(),
				(msm_mpd.rq_avg_poll_ms * NSEC_PER_MSEC));
		msm_mpd.task = kthread_run(msm_mpd_do_update_scm,
					      &msm_mpd.data, "msm_mpdecision");
		if (IS_ERR(msm_mpd.task))
			return -EFAULT;

		msm_mpd.hptask = kthread_run(msm_mpd_do_hotplug,
						&msm_mpd.hpupdate, "msm_hp");
		if (IS_ERR(msm_mpd.hptask))
			return -EFAULT;

		for_each_online_cpu(cpu)
			hrtimer_start(&per_cpu(rq_avg_poll_timer, cpu),
				      msm_mpd.next_update,
				      HRTIMER_MODE_ABS_PINNED);
		cpu_pm_register_notifier(&msm_mpd_idle_nb);
		register_cpu_notifier(&msm_mpd_hotplug_nb);
		msm_mpd.enabled = 1;
	} else {
		for_each_online_cpu(cpu)
			hrtimer_cancel(&per_cpu(rq_avg_poll_timer, cpu));
		kthread_stop(msm_mpd.hptask);
		kthread_stop(msm_mpd.task);
		cpu_pm_unregister_notifier(&msm_mpd_idle_nb);
		unregister_cpu_notifier(&msm_mpd_hotplug_nb);
		msm_mpd.enabled = 0;
	}

	return ret;
}

static int msm_mpd_set_rq_avg_poll_ms(uint32_t val)
{
	/*
	 * No need to do anything. Just let the timer set its own next poll
	 * interval when it next fires.
	 */
	msm_mpd.rq_avg_poll_ms = val;
	return 0;
}

static int msm_mpd_set_iowait_threshold_pct(uint32_t val)
{
	/*
	 * No need to do anything. Just let the timer set its own next poll
	 * interval when it next fires.
	 */
	msm_mpd.iowait_threshold_pct = val;
	return 0;
}

#define MPD_ALGO_PARAM(_name, _param) \
static ssize_t msm_mpd_attr_##_name##_show(struct kobject *kobj, \
			struct kobj_attribute *attr, char *buf) \
{ \
	return snprintf(buf, PAGE_SIZE, "%d\n", _param); \
} \
static ssize_t msm_mpd_attr_##_name##_store(struct kobject *kobj, \
		struct kobj_attribute *attr, const char *buf, size_t count) \
{ \
	int ret = 0; \
	uint32_t val; \
	uint32_t old_val; \
	mutex_lock(&msm_mpd.lock); \
	ret = kstrtouint(buf, 10, &val); \
	if (ret) { \
		pr_err("Invalid input %s for %s %d\n", \
				buf, __stringify(_name), ret);\
		return 0; \
	} \
	old_val = _param; \
	_param = val; \
	ret = msm_mpd_scm_set_algo_params(&msm_mpd.mp_param); \
	if (ret) { \
		pr_err("Error %d returned when setting algo param %s to %d\n",\
				ret, __stringify(_name), val); \
		_param = old_val; \
	} \
	mutex_unlock(&msm_mpd.lock); \
	return count; \
}

#define MPD_PARAM(_name, _param) \
static ssize_t msm_mpd_attr_##_name##_show(struct kobject *kobj, \
			struct kobj_attribute *attr, char *buf) \
{ \
	return snprintf(buf, PAGE_SIZE, "%d\n", _param); \
} \
static ssize_t msm_mpd_attr_##_name##_store(struct kobject *kobj, \
		struct kobj_attribute *attr, const char *buf, size_t count) \
{ \
	int ret = 0; \
	uint32_t val; \
	uint32_t old_val; \
	mutex_lock(&msm_mpd.lock); \
	ret = kstrtouint(buf, 10, &val); \
	if (ret) { \
		pr_err("Invalid input %s for %s %d\n", \
				buf, __stringify(_name), ret);\
		return 0; \
	} \
	old_val = _param; \
	ret = msm_mpd_set_##_name(val); \
	if (ret) { \
		pr_err("Error %d returned when setting algo param %s to %d\n",\
				ret, __stringify(_name), val); \
		_param = old_val; \
	} \
	mutex_unlock(&msm_mpd.lock); \
	return count; \
}

#define MPD_RW_ATTRIB(i, _name) \
	msm_mpd.attrib._name.attr.name = __stringify(_name); \
	msm_mpd.attrib._name.attr.mode = S_IRUGO | S_IWUSR; \
	msm_mpd.attrib._name.show = msm_mpd_attr_##_name##_show; \
	msm_mpd.attrib._name.store = msm_mpd_attr_##_name##_store; \
	msm_mpd.attrib.attrib_group.attrs[i] = &msm_mpd.attrib._name.attr;

MPD_PARAM(enabled, msm_mpd.enabled);
MPD_PARAM(rq_avg_poll_ms, msm_mpd.rq_avg_poll_ms);
MPD_PARAM(iowait_threshold_pct, msm_mpd.iowait_threshold_pct);
MPD_ALGO_PARAM(em_win_size_min_us, msm_mpd.mp_param.em_win_size_min_us);
MPD_ALGO_PARAM(em_win_size_max_us, msm_mpd.mp_param.em_win_size_max_us);
MPD_ALGO_PARAM(em_max_util_pct, msm_mpd.mp_param.em_max_util_pct);
MPD_ALGO_PARAM(mp_em_rounding_point_min,
				msm_mpd.mp_param.mp_em_rounding_point_min);
MPD_ALGO_PARAM(mp_em_rounding_point_max,
				msm_mpd.mp_param.mp_em_rounding_point_max);
MPD_ALGO_PARAM(online_util_pct_min, msm_mpd.mp_param.online_util_pct_min);
MPD_ALGO_PARAM(online_util_pct_max, msm_mpd.mp_param.online_util_pct_max);
MPD_ALGO_PARAM(slack_time_min_us, msm_mpd.mp_param.slack_time_min_us);
MPD_ALGO_PARAM(slack_time_max_us, msm_mpd.mp_param.slack_time_max_us);
MPD_ALGO_PARAM(hp_up_max_ms, hp_latencies.hp_up_max_ms);
MPD_ALGO_PARAM(hp_up_ms, hp_latencies.hp_up_ms);
MPD_ALGO_PARAM(hp_up_count, hp_latencies.hp_up_count);
MPD_ALGO_PARAM(hp_dw_max_ms, hp_latencies.hp_dw_max_ms);
MPD_ALGO_PARAM(hp_dw_ms, hp_latencies.hp_dw_ms);
MPD_ALGO_PARAM(hp_dw_count, hp_latencies.hp_dw_count);

static int __devinit msm_mpd_probe(struct platform_device *pdev)
{
	struct kobject *module_kobj = NULL;
	int ret = 0;
	const int attr_count = 19;
	struct msm_mpd_algo_param *param = NULL;

	param = pdev->dev.platform_data;

	module_kobj = kset_find_obj(module_kset, KBUILD_MODNAME);
	if (!module_kobj) {
		pr_err("Cannot find kobject for module %s\n", KBUILD_MODNAME);
		ret = -ENOENT;
		goto done;
	}

	msm_mpd.attrib.attrib_group.attrs =
		kzalloc(attr_count * sizeof(struct attribute *), GFP_KERNEL);
	if (!msm_mpd.attrib.attrib_group.attrs) {
		ret = -ENOMEM;
		goto done;
	}

	MPD_RW_ATTRIB(0, enabled);
	MPD_RW_ATTRIB(1, rq_avg_poll_ms);
	MPD_RW_ATTRIB(2, iowait_threshold_pct);
	MPD_RW_ATTRIB(3, em_win_size_min_us);
	MPD_RW_ATTRIB(4, em_win_size_max_us);
	MPD_RW_ATTRIB(5, em_max_util_pct);
	MPD_RW_ATTRIB(6, mp_em_rounding_point_min);
	MPD_RW_ATTRIB(7, mp_em_rounding_point_max);
	MPD_RW_ATTRIB(8, online_util_pct_min);
	MPD_RW_ATTRIB(9, online_util_pct_max);
	MPD_RW_ATTRIB(10, slack_time_min_us);
	MPD_RW_ATTRIB(11, slack_time_max_us);
	MPD_RW_ATTRIB(12, hp_up_max_ms);
	MPD_RW_ATTRIB(13, hp_up_ms);
	MPD_RW_ATTRIB(14, hp_up_count);
	MPD_RW_ATTRIB(15, hp_dw_max_ms);
	MPD_RW_ATTRIB(16, hp_dw_ms);
	MPD_RW_ATTRIB(17, hp_dw_count);

	msm_mpd.attrib.attrib_group.attrs[18] = NULL;
	ret = sysfs_create_group(module_kobj, &msm_mpd.attrib.attrib_group);
	if (ret)
		pr_err("Unable to create sysfs objects :%d\n", ret);

	msm_mpd.rq_avg_poll_ms = DEFAULT_RQ_AVG_POLL_MS;

	memcpy(&msm_mpd.mp_param, param, sizeof(struct msm_mpd_algo_param));

	debugfs_base = debugfs_create_dir("msm_mpdecision", NULL);
	if (!debugfs_base) {
		pr_err("Cannot create debugfs base msm_mpdecision\n");
		ret = -ENOENT;
		goto done;
	}

done:
	if (ret && debugfs_base)
		debugfs_remove(debugfs_base);

	return ret;
}

static int __devexit msm_mpd_remove(struct platform_device *pdev)
{
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver msm_mpd_driver = {
	.probe	= msm_mpd_probe,
	.remove	= __devexit_p(msm_mpd_remove),
	.driver	= {
		.name	= "msm_mpdecision",
		.owner	= THIS_MODULE,
	},
};

static int __init msm_mpdecision_init(void)
{
	int cpu;
	if (!msm_mpd_enabled) {
		pr_info("Not enabled\n");
		return 0;
	}

	num_present_hundreds = 100 * num_present_cpus();

	hrtimer_init(&msm_mpd.slack_timer, CLOCK_MONOTONIC,
			HRTIMER_MODE_REL_PINNED);
	msm_mpd.slack_timer.function = msm_mpd_slack_timer;

	for_each_possible_cpu(cpu) {
		hrtimer_init(&per_cpu(rq_avg_poll_timer, cpu),
			     CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED);
		per_cpu(rq_avg_poll_timer, cpu).function
				= msm_mpd_rq_avg_poll_timer;
	}
	mutex_init(&msm_mpd.lock);
	init_waitqueue_head(&msm_mpd.wait_q);
	init_waitqueue_head(&msm_mpd.wait_hpq);
	return platform_driver_register(&msm_mpd_driver);
}
late_initcall(msm_mpdecision_init);