/* * drivers/cpufreq/cpufreq_governor.c * * CPUFREQ governors common code * * Copyright (C) 2001 Russell King * (C) 2003 Venkatesh Pallipadi . * (C) 2003 Jun Nakajima * (C) 2009 Alexander Clouter * (c) 2012 Viresh Kumar * * 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 #include #include #include #include #include #include #include #include #include "cpufreq_governor.h" 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 = cputime_to_usecs(cur_wall_time); return cputime_to_usecs(idle_time); } u64 get_cpu_idle_time(unsigned int cpu, u64 *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; } 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);