| /* |
| * drivers/cpufreq/cpufreq_governor.c |
| * |
| * 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> |
| * Copyright (c) 2014, NVIDIA CORPORATION. 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 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/slab.h> |
| #include <linux/tick.h> |
| #include <linux/types.h> |
| #include <linux/workqueue.h> |
| |
| #include "cpufreq_governor.h" |
| |
| static struct attribute_group *get_sysfs_attr(struct dbs_data *dbs_data) |
| { |
| if (have_governor_per_policy()) |
| return dbs_data->cdata->attr_group_gov_pol; |
| else |
| return dbs_data->cdata->attr_group_gov_sys; |
| } |
| |
| 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, int io_busy) |
| { |
| u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); |
| |
| if (idle_time == -1ULL) |
| return get_cpu_idle_time_jiffy(cpu, wall); |
| else if (!io_busy) |
| 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->cdata->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->cdata->governor == GOV_ONDEMAND) |
| ignore_nice = od_tuners->ignore_nice_load; |
| else |
| ignore_nice = cs_tuners->ignore_nice_load; |
| |
| 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; |
| unsigned int idle_time, wall_time; |
| unsigned int load; |
| int io_busy = 0; |
| |
| j_cdbs = dbs_data->cdata->get_cpu_cdbs(j); |
| |
| /* |
| * 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 do not add |
| * the iowait time to the cpu idle time. |
| */ |
| if (dbs_data->cdata->governor == GOV_ONDEMAND) |
| io_busy = od_tuners->io_is_busy; |
| cur_idle_time = get_cpu_idle_time(j, &cur_wall_time, io_busy); |
| |
| 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 (unlikely(!wall_time || wall_time < idle_time)) |
| continue; |
| |
| load = 100 * (wall_time - idle_time) / wall_time; |
| |
| if (dbs_data->cdata->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->cdata->gov_check_cpu(cpu, max_load); |
| } |
| EXPORT_SYMBOL_GPL(dbs_check_cpu); |
| |
| static inline void __gov_queue_work(int cpu, struct dbs_data *dbs_data, |
| unsigned int delay) |
| { |
| struct cpu_dbs_common_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu); |
| |
| mod_delayed_work_on(cpu, system_wq, &cdbs->work, delay); |
| } |
| |
| void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy, |
| unsigned int delay, bool all_cpus) |
| { |
| int i; |
| |
| if (!policy->governor_enabled) |
| return; |
| |
| if (!all_cpus) { |
| __gov_queue_work(smp_processor_id(), dbs_data, delay); |
| } else { |
| for_each_cpu(i, policy->cpus) |
| __gov_queue_work(i, dbs_data, delay); |
| } |
| } |
| EXPORT_SYMBOL_GPL(gov_queue_work); |
| |
| static inline void gov_cancel_work(struct dbs_data *dbs_data, |
| struct cpufreq_policy *policy) |
| { |
| struct cpu_dbs_common_info *cdbs; |
| int i; |
| |
| for_each_cpu(i, policy->cpus) { |
| cdbs = dbs_data->cdata->get_cpu_cdbs(i); |
| cancel_delayed_work_sync(&cdbs->work); |
| } |
| } |
| |
| /* Will return if we need to evaluate cpu load again or not */ |
| bool need_load_eval(struct cpu_dbs_common_info *cdbs, |
| unsigned int sampling_rate) |
| { |
| if (policy_is_shared(cdbs->cur_policy)) { |
| ktime_t time_now = ktime_get(); |
| s64 delta_us = ktime_us_delta(time_now, cdbs->time_stamp); |
| |
| /* Do nothing if we recently have sampled */ |
| if (delta_us < (s64)(sampling_rate / 2)) |
| return false; |
| else |
| cdbs->time_stamp = time_now; |
| } |
| |
| return true; |
| } |
| EXPORT_SYMBOL_GPL(need_load_eval); |
| |
| static void set_sampling_rate(struct dbs_data *dbs_data, |
| unsigned int sampling_rate) |
| { |
| if (dbs_data->cdata->governor == GOV_CONSERVATIVE) { |
| struct cs_dbs_tuners *cs_tuners = dbs_data->tuners; |
| cs_tuners->sampling_rate = sampling_rate; |
| } else { |
| struct od_dbs_tuners *od_tuners = dbs_data->tuners; |
| od_tuners->sampling_rate = sampling_rate; |
| } |
| } |
| |
| int cpufreq_governor_dbs(struct cpufreq_policy *policy, |
| struct common_dbs_data *cdata, unsigned int event) |
| { |
| struct dbs_data *dbs_data; |
| struct od_cpu_dbs_info_s *od_dbs_info = NULL; |
| struct cs_cpu_dbs_info_s *cs_dbs_info = NULL; |
| struct od_ops *od_ops = NULL; |
| struct od_dbs_tuners *od_tuners = NULL; |
| struct cs_dbs_tuners *cs_tuners = NULL; |
| struct cpu_dbs_common_info *cpu_cdbs; |
| unsigned int sampling_rate, latency, ignore_nice, j, cpu = policy->cpu; |
| int io_busy = 0; |
| int rc; |
| |
| if (have_governor_per_policy()) |
| dbs_data = policy->governor_data; |
| else |
| dbs_data = cdata->gdbs_data; |
| |
| WARN_ON(!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)); |
| |
| switch (event) { |
| case CPUFREQ_GOV_POLICY_INIT: |
| if (have_governor_per_policy()) { |
| WARN_ON(dbs_data); |
| } else if (dbs_data) { |
| dbs_data->usage_count++; |
| policy->governor_data = dbs_data; |
| return 0; |
| } |
| |
| dbs_data = kzalloc(sizeof(*dbs_data), GFP_KERNEL); |
| if (!dbs_data) { |
| pr_err("%s: POLICY_INIT: kzalloc failed\n", __func__); |
| return -ENOMEM; |
| } |
| |
| dbs_data->cdata = cdata; |
| dbs_data->usage_count = 1; |
| rc = cdata->init(dbs_data); |
| if (rc) { |
| pr_err("%s: POLICY_INIT: init() failed\n", __func__); |
| kfree(dbs_data); |
| return rc; |
| } |
| |
| rc = sysfs_create_group(get_governor_parent_kobj(policy), |
| get_sysfs_attr(dbs_data)); |
| if (rc) { |
| cdata->exit(dbs_data); |
| kfree(dbs_data); |
| return rc; |
| } |
| |
| policy->governor_data = dbs_data; |
| |
| /* policy latency is in nS. Convert it to uS first */ |
| latency = policy->cpuinfo.transition_latency / 1000; |
| if (latency == 0) |
| latency = 1; |
| |
| /* Bring kernel and HW constraints together */ |
| dbs_data->min_sampling_rate = max(dbs_data->min_sampling_rate, |
| MIN_LATENCY_MULTIPLIER * latency); |
| set_sampling_rate(dbs_data, max(dbs_data->min_sampling_rate, |
| latency * LATENCY_MULTIPLIER)); |
| |
| if ((cdata->governor == GOV_CONSERVATIVE) && |
| (!policy->governor->initialized)) { |
| struct cs_ops *cs_ops = dbs_data->cdata->gov_ops; |
| |
| cpufreq_register_notifier(cs_ops->notifier_block, |
| CPUFREQ_TRANSITION_NOTIFIER); |
| } |
| |
| if (!have_governor_per_policy()) |
| cdata->gdbs_data = dbs_data; |
| |
| return 0; |
| case CPUFREQ_GOV_POLICY_EXIT: |
| if (!--dbs_data->usage_count) { |
| sysfs_remove_group(get_governor_parent_kobj(policy), |
| get_sysfs_attr(dbs_data)); |
| |
| if ((dbs_data->cdata->governor == GOV_CONSERVATIVE) && |
| (policy->governor->initialized == 1)) { |
| struct cs_ops *cs_ops = dbs_data->cdata->gov_ops; |
| |
| cpufreq_unregister_notifier(cs_ops->notifier_block, |
| CPUFREQ_TRANSITION_NOTIFIER); |
| } |
| |
| cdata->exit(dbs_data); |
| kfree(dbs_data); |
| cdata->gdbs_data = NULL; |
| } |
| |
| policy->governor_data = NULL; |
| return 0; |
| } |
| |
| cpu_cdbs = dbs_data->cdata->get_cpu_cdbs(cpu); |
| |
| if (dbs_data->cdata->governor == GOV_CONSERVATIVE) { |
| cs_tuners = dbs_data->tuners; |
| cs_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu); |
| sampling_rate = cs_tuners->sampling_rate; |
| ignore_nice = cs_tuners->ignore_nice_load; |
| } else { |
| od_tuners = dbs_data->tuners; |
| od_dbs_info = dbs_data->cdata->get_cpu_dbs_info_s(cpu); |
| sampling_rate = od_tuners->sampling_rate; |
| ignore_nice = od_tuners->ignore_nice_load; |
| od_ops = dbs_data->cdata->gov_ops; |
| io_busy = od_tuners->io_is_busy; |
| } |
| |
| switch (event) { |
| case CPUFREQ_GOV_START: |
| if (!policy->cur) |
| return -EINVAL; |
| |
| mutex_lock(&dbs_data->mutex); |
| |
| for_each_cpu(j, policy->cpus) { |
| struct cpu_dbs_common_info *j_cdbs = |
| dbs_data->cdata->get_cpu_cdbs(j); |
| |
| j_cdbs->cpu = j; |
| j_cdbs->cur_policy = policy; |
| j_cdbs->prev_cpu_idle = get_cpu_idle_time(j, |
| &j_cdbs->prev_cpu_wall, io_busy); |
| if (ignore_nice) |
| j_cdbs->prev_cpu_nice = |
| kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| |
| mutex_init(&j_cdbs->timer_mutex); |
| INIT_DEFERRABLE_WORK(&j_cdbs->work, |
| dbs_data->cdata->gov_dbs_timer); |
| } |
| |
| /* |
| * conservative does not implement micro like ondemand |
| * governor, thus we are bound to jiffes/HZ |
| */ |
| if (dbs_data->cdata->governor == GOV_CONSERVATIVE) { |
| cs_dbs_info->down_skip = 0; |
| cs_dbs_info->enable = 1; |
| cs_dbs_info->requested_freq = policy->cur; |
| } else { |
| od_dbs_info->rate_mult = 1; |
| od_dbs_info->sample_type = OD_NORMAL_SAMPLE; |
| od_ops->powersave_bias_init_cpu(cpu); |
| } |
| |
| mutex_unlock(&dbs_data->mutex); |
| |
| /* Initiate timer time stamp */ |
| cpu_cdbs->time_stamp = ktime_get(); |
| |
| gov_queue_work(dbs_data, policy, |
| delay_for_sampling_rate(sampling_rate), true); |
| break; |
| |
| case CPUFREQ_GOV_STOP: |
| if (dbs_data->cdata->governor == GOV_CONSERVATIVE) |
| cs_dbs_info->enable = 0; |
| |
| gov_cancel_work(dbs_data, policy); |
| |
| mutex_lock(&dbs_data->mutex); |
| mutex_destroy(&cpu_cdbs->timer_mutex); |
| cpu_cdbs->cur_policy = NULL; |
| |
| mutex_unlock(&dbs_data->mutex); |
| |
| break; |
| |
| case CPUFREQ_GOV_LIMITS: |
| mutex_lock(&dbs_data->mutex); |
| if (!cpu_cdbs->cur_policy) { |
| mutex_unlock(&dbs_data->mutex); |
| break; |
| } |
| 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); |
| mutex_unlock(&dbs_data->mutex); |
| break; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(cpufreq_governor_dbs); |