*
* CPUFREQ governors common code
*
+ * Copyright (C) 2001 Russell King
+ * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
+ * (C) 2003 Jun Nakajima <jun.nakajima@intel.com>
+ * (C) 2009 Alexander Clouter <alex@digriz.org.uk>
+ * (c) 2012 Viresh Kumar <viresh.kumar@linaro.org>
+ *
* 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.
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <asm/cputime.h>
+#include <linux/cpufreq.h>
+#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/kernel_stat.h>
+#include <linux/mutex.h>
#include <linux/tick.h>
#include <linux/types.h>
-/*
- * Code picked from earlier governer implementations
- */
+#include <linux/workqueue.h>
+
+#include "cpufreq_governor.h"
+
static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall)
{
u64 idle_time;
return cputime_to_usecs(idle_time);
}
-cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
+u64 get_cpu_idle_time(unsigned int cpu, u64 *wall)
{
u64 idle_time = get_cpu_idle_time_us(cpu, NULL);
return idle_time;
}
EXPORT_SYMBOL_GPL(get_cpu_idle_time);
+
+void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
+{
+ struct cpu_dbs_common_info *cdbs = dbs_data->get_cpu_cdbs(cpu);
+ struct od_dbs_tuners *od_tuners = dbs_data->tuners;
+ struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
+ struct cpufreq_policy *policy;
+ unsigned int max_load = 0;
+ unsigned int ignore_nice;
+ unsigned int j;
+
+ if (dbs_data->governor == GOV_ONDEMAND)
+ ignore_nice = od_tuners->ignore_nice;
+ else
+ ignore_nice = cs_tuners->ignore_nice;
+
+ policy = cdbs->cur_policy;
+
+ /* Get Absolute Load (in terms of freq for ondemand gov) */
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_common_info *j_cdbs;
+ u64 cur_wall_time, cur_idle_time, cur_iowait_time;
+ unsigned int idle_time, wall_time, iowait_time;
+ unsigned int load;
+
+ j_cdbs = dbs_data->get_cpu_cdbs(j);
+
+ cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+
+ wall_time = (unsigned int)
+ (cur_wall_time - j_cdbs->prev_cpu_wall);
+ j_cdbs->prev_cpu_wall = cur_wall_time;
+
+ idle_time = (unsigned int)
+ (cur_idle_time - j_cdbs->prev_cpu_idle);
+ j_cdbs->prev_cpu_idle = cur_idle_time;
+
+ if (ignore_nice) {
+ u64 cur_nice;
+ unsigned long cur_nice_jiffies;
+
+ cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] -
+ cdbs->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);
+
+ cdbs->prev_cpu_nice =
+ kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+ idle_time += jiffies_to_usecs(cur_nice_jiffies);
+ }
+
+ if (dbs_data->governor == GOV_ONDEMAND) {
+ struct od_cpu_dbs_info_s *od_j_dbs_info =
+ dbs_data->get_cpu_dbs_info_s(cpu);
+
+ cur_iowait_time = get_cpu_iowait_time_us(j,
+ &cur_wall_time);
+ if (cur_iowait_time == -1ULL)
+ cur_iowait_time = 0;
+
+ iowait_time = (unsigned int) (cur_iowait_time -
+ od_j_dbs_info->prev_cpu_iowait);
+ od_j_dbs_info->prev_cpu_iowait = cur_iowait_time;
+
+ /*
+ * 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 (od_tuners->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;
+
+ if (dbs_data->governor == GOV_ONDEMAND) {
+ int freq_avg = __cpufreq_driver_getavg(policy, j);
+ if (freq_avg <= 0)
+ freq_avg = policy->cur;
+
+ load *= freq_avg;
+ }
+
+ if (load > max_load)
+ max_load = load;
+ }
+
+ dbs_data->gov_check_cpu(cpu, max_load);
+}
+EXPORT_SYMBOL_GPL(dbs_check_cpu);
+
+static inline void dbs_timer_init(struct dbs_data *dbs_data,
+ struct cpu_dbs_common_info *cdbs, unsigned int sampling_rate)
+{
+ int delay = delay_for_sampling_rate(sampling_rate);
+
+ INIT_DEFERRABLE_WORK(&cdbs->work, dbs_data->gov_dbs_timer);
+ schedule_delayed_work_on(cdbs->cpu, &cdbs->work, delay);
+}
+
+static inline void dbs_timer_exit(struct cpu_dbs_common_info *cdbs)
+{
+ cancel_delayed_work_sync(&cdbs->work);
+}
+
+int cpufreq_governor_dbs(struct dbs_data *dbs_data,
+ struct cpufreq_policy *policy, unsigned int event)
+{
+ struct od_cpu_dbs_info_s *od_dbs_info = NULL;
+ struct cs_cpu_dbs_info_s *cs_dbs_info = NULL;
+ struct od_dbs_tuners *od_tuners = dbs_data->tuners;
+ struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
+ struct cpu_dbs_common_info *cpu_cdbs;
+ unsigned int *sampling_rate, latency, ignore_nice, j, cpu = policy->cpu;
+ int rc;
+
+ cpu_cdbs = dbs_data->get_cpu_cdbs(cpu);
+
+ if (dbs_data->governor == GOV_CONSERVATIVE) {
+ cs_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
+ sampling_rate = &cs_tuners->sampling_rate;
+ ignore_nice = cs_tuners->ignore_nice;
+ } else {
+ od_dbs_info = dbs_data->get_cpu_dbs_info_s(cpu);
+ sampling_rate = &od_tuners->sampling_rate;
+ ignore_nice = od_tuners->ignore_nice;
+ }
+
+ switch (event) {
+ case CPUFREQ_GOV_START:
+ if ((!cpu_online(cpu)) || (!policy->cur))
+ return -EINVAL;
+
+ mutex_lock(&dbs_data->mutex);
+
+ dbs_data->enable++;
+ cpu_cdbs->cpu = cpu;
+ for_each_cpu(j, policy->cpus) {
+ struct cpu_dbs_common_info *j_cdbs;
+ j_cdbs = dbs_data->get_cpu_cdbs(j);
+
+ j_cdbs->cur_policy = policy;
+ j_cdbs->prev_cpu_idle = get_cpu_idle_time(j,
+ &j_cdbs->prev_cpu_wall);
+ if (ignore_nice)
+ j_cdbs->prev_cpu_nice =
+ kcpustat_cpu(j).cpustat[CPUTIME_NICE];
+ }
+
+ /*
+ * Start the timerschedule work, when this governor is used for
+ * first time
+ */
+ if (dbs_data->enable != 1)
+ goto second_time;
+
+ rc = sysfs_create_group(cpufreq_global_kobject,
+ dbs_data->attr_group);
+ if (rc) {
+ mutex_unlock(&dbs_data->mutex);
+ return rc;
+ }
+
+ /* policy latency is in nS. Convert it to uS first */
+ latency = policy->cpuinfo.transition_latency / 1000;
+ if (latency == 0)
+ latency = 1;
+
+ /*
+ * conservative does not implement micro like ondemand
+ * governor, thus we are bound to jiffes/HZ
+ */
+ if (dbs_data->governor == GOV_CONSERVATIVE) {
+ struct cs_ops *ops = dbs_data->gov_ops;
+
+ cpufreq_register_notifier(ops->notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+
+ dbs_data->min_sampling_rate = MIN_SAMPLING_RATE_RATIO *
+ jiffies_to_usecs(10);
+ } else {
+ struct od_ops *ops = dbs_data->gov_ops;
+
+ od_tuners->io_is_busy = ops->io_busy();
+ }
+
+ /* Bring kernel and HW constraints together */
+ dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate,
+ MIN_LATENCY_MULTIPLIER * latency);
+ *sampling_rate = max(dbs_data->min_sampling_rate, latency *
+ LATENCY_MULTIPLIER);
+
+second_time:
+ if (dbs_data->governor == GOV_CONSERVATIVE) {
+ cs_dbs_info->down_skip = 0;
+ cs_dbs_info->enable = 1;
+ cs_dbs_info->requested_freq = policy->cur;
+ } else {
+ struct od_ops *ops = dbs_data->gov_ops;
+ od_dbs_info->rate_mult = 1;
+ od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
+ ops->powersave_bias_init_cpu(cpu);
+ }
+ mutex_unlock(&dbs_data->mutex);
+
+ mutex_init(&cpu_cdbs->timer_mutex);
+ dbs_timer_init(dbs_data, cpu_cdbs, *sampling_rate);
+ break;
+
+ case CPUFREQ_GOV_STOP:
+ if (dbs_data->governor == GOV_CONSERVATIVE)
+ cs_dbs_info->enable = 0;
+
+ dbs_timer_exit(cpu_cdbs);
+
+ mutex_lock(&dbs_data->mutex);
+ mutex_destroy(&cpu_cdbs->timer_mutex);
+ dbs_data->enable--;
+ if (!dbs_data->enable) {
+ struct cs_ops *ops = dbs_data->gov_ops;
+
+ sysfs_remove_group(cpufreq_global_kobject,
+ dbs_data->attr_group);
+ if (dbs_data->governor == GOV_CONSERVATIVE)
+ cpufreq_unregister_notifier(ops->notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ }
+ mutex_unlock(&dbs_data->mutex);
+
+ break;
+
+ case CPUFREQ_GOV_LIMITS:
+ mutex_lock(&cpu_cdbs->timer_mutex);
+ if (policy->max < cpu_cdbs->cur_policy->cur)
+ __cpufreq_driver_target(cpu_cdbs->cur_policy,
+ policy->max, CPUFREQ_RELATION_H);
+ else if (policy->min > cpu_cdbs->cur_policy->cur)
+ __cpufreq_driver_target(cpu_cdbs->cur_policy,
+ policy->min, CPUFREQ_RELATION_L);
+ dbs_check_cpu(dbs_data, cpu);
+ mutex_unlock(&cpu_cdbs->timer_mutex);
+ break;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);
projects / karo-tx-linux.git / blobdiff