blob: ea08f4bfe249a56f98b4ec75de6705b422c533ef [file] [log] [blame]
/* Copyright (c) 2010-2012, Code Aurora Forum. 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.
*
*/
/*
* Qualcomm MSM Runqueue Stats and cpu utilization Interface for Userspace
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/hrtimer.h>
#include <linux/cpu.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/notifier.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/rq_stats.h>
#include <linux/cpufreq.h>
#include <linux/kernel_stat.h>
#include <linux/tick.h>
#include <asm/smp_plat.h>
#define MAX_LONG_SIZE 24
#define DEFAULT_RQ_POLL_JIFFIES 1
#define DEFAULT_DEF_TIMER_JIFFIES 5
struct notifier_block freq_transition;
struct notifier_block cpu_hotplug;
struct cpu_load_data {
cputime64_t prev_cpu_idle;
cputime64_t prev_cpu_wall;
cputime64_t prev_cpu_iowait;
unsigned int avg_load_maxfreq;
unsigned int samples;
unsigned int window_size;
unsigned int cur_freq;
unsigned int policy_max;
cpumask_var_t related_cpus;
struct mutex cpu_load_mutex;
};
static DEFINE_PER_CPU(struct cpu_load_data, cpuload);
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;
}
static int update_average_load(unsigned int freq, unsigned int cpu)
{
struct cpu_load_data *pcpu = &per_cpu(cpuload, cpu);
cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
unsigned int idle_time, wall_time, iowait_time;
unsigned int cur_load, load_at_max_freq;
cur_idle_time = get_cpu_idle_time(cpu, &cur_wall_time);
cur_iowait_time = get_cpu_iowait_time(cpu, &cur_wall_time);
wall_time = (unsigned int) (cur_wall_time - pcpu->prev_cpu_wall);
pcpu->prev_cpu_wall = cur_wall_time;
idle_time = (unsigned int) (cur_idle_time - pcpu->prev_cpu_idle);
pcpu->prev_cpu_idle = cur_idle_time;
iowait_time = (unsigned int) (cur_iowait_time - pcpu->prev_cpu_iowait);
pcpu->prev_cpu_iowait = cur_iowait_time;
if (idle_time >= iowait_time)
idle_time -= iowait_time;
if (unlikely(!wall_time || wall_time < idle_time))
return 0;
cur_load = 100 * (wall_time - idle_time) / wall_time;
/* Calculate the scaled load across CPU */
load_at_max_freq = (cur_load * freq) / pcpu->policy_max;
if (!pcpu->avg_load_maxfreq) {
/* This is the first sample in this window*/
pcpu->avg_load_maxfreq = load_at_max_freq;
pcpu->window_size = wall_time;
} else {
/*
* The is already a sample available in this window.
* Compute weighted average with prev entry, so that we get
* the precise weighted load.
*/
pcpu->avg_load_maxfreq =
((pcpu->avg_load_maxfreq * pcpu->window_size) +
(load_at_max_freq * wall_time)) /
(wall_time + pcpu->window_size);
pcpu->window_size += wall_time;
}
return 0;
}
static unsigned int report_load_at_max_freq(void)
{
int cpu;
struct cpu_load_data *pcpu;
unsigned int total_load = 0;
for_each_online_cpu(cpu) {
pcpu = &per_cpu(cpuload, cpu);
mutex_lock(&pcpu->cpu_load_mutex);
update_average_load(pcpu->cur_freq, cpu);
total_load += pcpu->avg_load_maxfreq;
pcpu->avg_load_maxfreq = 0;
mutex_unlock(&pcpu->cpu_load_mutex);
}
return total_load;
}
static int cpufreq_transition_handler(struct notifier_block *nb,
unsigned long val, void *data)
{
struct cpufreq_freqs *freqs = data;
struct cpu_load_data *this_cpu = &per_cpu(cpuload, freqs->cpu);
int j;
switch (val) {
case CPUFREQ_POSTCHANGE:
for_each_cpu(j, this_cpu->related_cpus) {
struct cpu_load_data *pcpu = &per_cpu(cpuload, j);
mutex_lock(&pcpu->cpu_load_mutex);
update_average_load(freqs->old, freqs->cpu);
pcpu->cur_freq = freqs->new;
mutex_unlock(&pcpu->cpu_load_mutex);
}
break;
}
return 0;
}
static int cpu_hotplug_handler(struct notifier_block *nb,
unsigned long val, void *data)
{
unsigned int cpu = (unsigned long)data;
struct cpu_load_data *this_cpu = &per_cpu(cpuload, cpu);
switch (val) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
this_cpu->avg_load_maxfreq = 0;
}
return NOTIFY_OK;
}
static void def_work_fn(struct work_struct *work)
{
int64_t diff;
diff = ktime_to_ns(ktime_get()) - rq_info.def_start_time;
do_div(diff, 1000 * 1000);
rq_info.def_interval = (unsigned int) diff;
/* Notify polling threads on change of value */
sysfs_notify(rq_info.kobj, NULL, "def_timer_ms");
}
static ssize_t run_queue_avg_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
unsigned int val = 0;
unsigned long flags = 0;
spin_lock_irqsave(&rq_lock, flags);
/* rq avg currently available only on one core */
val = rq_info.rq_avg;
rq_info.rq_avg = 0;
spin_unlock_irqrestore(&rq_lock, flags);
return snprintf(buf, PAGE_SIZE, "%d.%d\n", val/10, val%10);
}
static struct kobj_attribute run_queue_avg_attr = __ATTR_RO(run_queue_avg);
static ssize_t show_run_queue_poll_ms(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
int ret = 0;
unsigned long flags = 0;
spin_lock_irqsave(&rq_lock, flags);
ret = snprintf(buf, MAX_LONG_SIZE, "%u\n",
jiffies_to_msecs(rq_info.rq_poll_jiffies));
spin_unlock_irqrestore(&rq_lock, flags);
return ret;
}
static ssize_t store_run_queue_poll_ms(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t count)
{
unsigned int val = 0;
unsigned long flags = 0;
static DEFINE_MUTEX(lock_poll_ms);
mutex_lock(&lock_poll_ms);
spin_lock_irqsave(&rq_lock, flags);
sscanf(buf, "%u", &val);
rq_info.rq_poll_jiffies = msecs_to_jiffies(val);
spin_unlock_irqrestore(&rq_lock, flags);
mutex_unlock(&lock_poll_ms);
return count;
}
static struct kobj_attribute run_queue_poll_ms_attr =
__ATTR(run_queue_poll_ms, S_IWUSR | S_IRUSR, show_run_queue_poll_ms,
store_run_queue_poll_ms);
static ssize_t show_def_timer_ms(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return snprintf(buf, MAX_LONG_SIZE, "%u\n", rq_info.def_interval);
}
static ssize_t store_def_timer_ms(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf, size_t count)
{
unsigned int val = 0;
sscanf(buf, "%u", &val);
rq_info.def_timer_jiffies = msecs_to_jiffies(val);
rq_info.def_start_time = ktime_to_ns(ktime_get());
return count;
}
static struct kobj_attribute def_timer_ms_attr =
__ATTR(def_timer_ms, S_IWUSR | S_IRUSR, show_def_timer_ms,
store_def_timer_ms);
static ssize_t show_cpu_normalized_load(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return snprintf(buf, MAX_LONG_SIZE, "%u\n", report_load_at_max_freq());
}
static struct kobj_attribute cpu_normalized_load_attr =
__ATTR(cpu_normalized_load, S_IWUSR | S_IRUSR, show_cpu_normalized_load,
NULL);
static struct attribute *rq_attrs[] = {
&cpu_normalized_load_attr.attr,
&def_timer_ms_attr.attr,
&run_queue_avg_attr.attr,
&run_queue_poll_ms_attr.attr,
NULL,
};
static struct attribute_group rq_attr_group = {
.attrs = rq_attrs,
};
static int init_rq_attribs(void)
{
int err;
rq_info.rq_avg = 0;
rq_info.attr_group = &rq_attr_group;
/* Create /sys/devices/system/cpu/cpu0/rq-stats/... */
rq_info.kobj = kobject_create_and_add("rq-stats",
&get_cpu_device(0)->kobj);
if (!rq_info.kobj)
return -ENOMEM;
err = sysfs_create_group(rq_info.kobj, rq_info.attr_group);
if (err)
kobject_put(rq_info.kobj);
else
kobject_uevent(rq_info.kobj, KOBJ_ADD);
return err;
}
static int __init msm_rq_stats_init(void)
{
int ret;
int i;
struct cpufreq_policy cpu_policy;
/* Bail out if this is not an SMP Target */
if (!is_smp()) {
rq_info.init = 0;
return -ENOSYS;
}
rq_wq = create_singlethread_workqueue("rq_stats");
BUG_ON(!rq_wq);
INIT_WORK(&rq_info.def_timer_work, def_work_fn);
spin_lock_init(&rq_lock);
rq_info.rq_poll_jiffies = DEFAULT_RQ_POLL_JIFFIES;
rq_info.def_timer_jiffies = DEFAULT_DEF_TIMER_JIFFIES;
rq_info.rq_poll_last_jiffy = 0;
rq_info.def_timer_last_jiffy = 0;
ret = init_rq_attribs();
rq_info.init = 1;
for_each_possible_cpu(i) {
struct cpu_load_data *pcpu = &per_cpu(cpuload, i);
mutex_init(&pcpu->cpu_load_mutex);
cpufreq_get_policy(&cpu_policy, i);
pcpu->policy_max = cpu_policy.cpuinfo.max_freq;
cpumask_copy(pcpu->related_cpus, cpu_policy.cpus);
}
freq_transition.notifier_call = cpufreq_transition_handler;
cpu_hotplug.notifier_call = cpu_hotplug_handler;
cpufreq_register_notifier(&freq_transition,
CPUFREQ_TRANSITION_NOTIFIER);
register_hotcpu_notifier(&cpu_hotplug);
return ret;
}
late_initcall(msm_rq_stats_init);