/* * CPUFreq governor based on scheduler-provided CPU utilization data. * * Copyright (C) 2016, Intel Corporation * Author: Rafael J. Wysocki * * 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 "sched.h" #include "tune.h" unsigned long boosted_cpu_util(int cpu); #define SUGOV_KTHREAD_PRIORITY 50 struct sugov_tunables { struct gov_attr_set attr_set; unsigned int up_rate_limit_us; unsigned int down_rate_limit_us; }; struct sugov_policy { struct cpufreq_policy *policy; struct sugov_tunables *tunables; struct list_head tunables_hook; raw_spinlock_t update_lock; /* For shared policies */ u64 last_freq_update_time; s64 min_rate_limit_ns; s64 up_rate_delay_ns; s64 down_rate_delay_ns; unsigned int next_freq; unsigned int cached_raw_freq; /* The next fields are only needed if fast switch cannot be used. */ struct irq_work irq_work; struct kthread_work work; struct mutex work_lock; struct kthread_worker worker; struct task_struct *thread; bool work_in_progress; bool need_freq_update; }; struct sugov_cpu { struct update_util_data update_util; struct sugov_policy *sg_policy; unsigned int cpu; bool iowait_boost_pending; unsigned int iowait_boost; unsigned int iowait_boost_max; u64 last_update; /* The fields below are only needed when sharing a policy. */ unsigned long util; unsigned long max; unsigned int flags; /* The field below is for single-CPU policies only. */ #ifdef CONFIG_NO_HZ_COMMON unsigned long saved_idle_calls; #endif }; static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu); /******************* exynos specific function *******************/ #define DEFAULT_EXPIRED_TIME 70 struct sugov_exynos { /* for slack timer */ unsigned long min; int enabled; bool started; int expired_time; struct timer_list timer; /* pm_qos_class */ int qos_min_class; }; static DEFINE_PER_CPU(struct sugov_exynos, sugov_exynos); static void sugov_stop_slack(int cpu); static void sugov_start_slack(int cpu); static void sugov_update_min(struct cpufreq_policy *policy); /************************ Governor internals ***********************/ struct sugov_policy_list { struct list_head list; struct sugov_policy *sg_policy; struct cpumask cpus; }; static LIST_HEAD(sugov_policy_list); static inline struct sugov_policy_list *find_sg_pol_list(struct cpufreq_policy *policy) { struct sugov_policy_list *sg_pol_list; list_for_each_entry(sg_pol_list, &sugov_policy_list, list) if (cpumask_test_cpu(policy->cpu, &sg_pol_list->cpus)) return sg_pol_list; return NULL; } static struct sugov_policy *sugov_restore_policy(struct cpufreq_policy *policy) { struct sugov_policy_list *sg_pol_list = sg_pol_list = find_sg_pol_list(policy); if (!sg_pol_list) return NULL; pr_info("Restore sg_policy(%d) from policy_list\(%x)n", policy->cpu, *(unsigned int *)cpumask_bits(&sg_pol_list->cpus)); return sg_pol_list->sg_policy; } static int sugov_save_policy(struct sugov_policy *sg_policy) { struct sugov_policy_list *sg_pol_list; struct cpufreq_policy *policy = sg_policy->policy; if (unlikely(!sg_policy)) return 0; sg_pol_list = find_sg_pol_list(policy); if (sg_pol_list) { pr_info("Already saved sg_policy(%d) to policy_list\(%x)n", policy->cpu, *(unsigned int *)cpumask_bits(&sg_pol_list->cpus)); return 1; } /* Back up sugov_policy to list */ sg_pol_list = kzalloc(sizeof(struct sugov_policy_list), GFP_KERNEL); if (!sg_pol_list) return 0; cpumask_copy(&sg_pol_list->cpus, policy->related_cpus); sg_pol_list->sg_policy = sg_policy; list_add(&sg_pol_list->list, &sugov_policy_list); pr_info("Save sg_policy(%d) to policy_list(%x)\n", policy->cpu, *(unsigned int *)cpumask_bits(&sg_pol_list->cpus)); return 1; } static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time) { s64 delta_ns; /* * Since cpufreq_update_util() is called with rq->lock held for * the @target_cpu, our per-cpu data is fully serialized. * * However, drivers cannot in general deal with cross-cpu * requests, so while get_next_freq() will work, our * sugov_update_commit() call may not for the fast switching platforms. * * Hence stop here for remote requests if they aren't supported * by the hardware, as calculating the frequency is pointless if * we cannot in fact act on it. * * For the slow switching platforms, the kthread is always scheduled on * the right set of CPUs and any CPU can find the next frequency and * schedule the kthread. */ if (sg_policy->policy->fast_switch_enabled && !cpufreq_can_do_remote_dvfs(sg_policy->policy)) return false; if (sg_policy->work_in_progress) return false; if (unlikely(sg_policy->need_freq_update)) { sg_policy->need_freq_update = false; /* * This happens when limits change, so forget the previous * next_freq value and force an update. */ sg_policy->next_freq = UINT_MAX; return true; } /* No need to recalculate next freq for min_rate_limit_us * at least. However we might still decide to further rate * limit once frequency change direction is decided, according * to the separate rate limits. */ delta_ns = time - sg_policy->last_freq_update_time; return delta_ns >= sg_policy->min_rate_limit_ns; } static bool sugov_up_down_rate_limit(struct sugov_policy *sg_policy, u64 time, unsigned int next_freq) { s64 delta_ns; delta_ns = time - sg_policy->last_freq_update_time; if (next_freq > sg_policy->next_freq && delta_ns < sg_policy->up_rate_delay_ns) return true; if (next_freq < sg_policy->next_freq && delta_ns < sg_policy->down_rate_delay_ns) return true; return false; } static int sugov_select_scaling_cpu(void) { int cpu, candidate = -1; unsigned long rt, util, min = INT_MAX; cpumask_t mask; cpumask_clear(&mask); cpumask_and(&mask, cpu_coregroup_mask(0), cpu_active_mask); /* Idle core of the boot cluster is selected to scaling cpu */ for_each_cpu(cpu, &mask) { rt = sched_get_rt_rq_util(cpu); util = boosted_cpu_util(cpu); if (util < min) { min = util; candidate = cpu; } } return candidate; } static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time, unsigned int next_freq) { struct cpufreq_policy *policy = sg_policy->policy; int cpu; if (sg_policy->next_freq == next_freq) return; if (sugov_up_down_rate_limit(sg_policy, time, next_freq)) return; sg_policy->next_freq = next_freq; sg_policy->last_freq_update_time = time; if (policy->fast_switch_enabled) { next_freq = cpufreq_driver_fast_switch(policy, next_freq); if (!next_freq) return; policy->cur = next_freq; trace_cpu_frequency(next_freq, smp_processor_id()); } else { cpu = sugov_select_scaling_cpu(); if (cpu < 0) return; sg_policy->work_in_progress = true; trace_cpu_frequency(next_freq, cpu); irq_work_queue_on(&sg_policy->irq_work, cpu); } } #ifdef CONFIG_FREQVAR_TUNE unsigned int freqvar_tipping_point(int cpu, unsigned int freq); #else static inline unsigned int freqvar_tipping_point(int cpu, unsigned int freq) { return freq + (freq >> 2); } #endif /** * get_next_freq - Compute a new frequency for a given cpufreq policy. * @sg_policy: schedutil policy object to compute the new frequency for. * @util: Current CPU utilization. * @max: CPU capacity. * * If the utilization is frequency-invariant, choose the new frequency to be * proportional to it, that is * * next_freq = C * max_freq * util / max * * Otherwise, approximate the would-be frequency-invariant utilization by * util_raw * (curr_freq / max_freq) which leads to * * next_freq = C * curr_freq * util_raw / max * * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8. * * The lowest driver-supported frequency which is equal or greater than the raw * next_freq (as calculated above) is returned, subject to policy min/max and * cpufreq driver limitations. */ static unsigned int get_next_freq(struct sugov_policy *sg_policy, unsigned long util, unsigned long max) { struct cpufreq_policy *policy = sg_policy->policy; unsigned int freq = arch_scale_freq_invariant() ? policy->max : policy->cur; freq = freqvar_tipping_point(policy->cpu, freq) * util / max; if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_MAX) return sg_policy->next_freq; sg_policy->cached_raw_freq = freq; freq = cpufreq_driver_resolve_freq(policy, freq); trace_cpu_frequency_sugov(util, freq, policy->cpu); return freq; } static void sugov_get_util(unsigned long *util, unsigned long *max, int cpu) { unsigned long max_cap; max_cap = arch_scale_cpu_capacity(NULL, cpu); *util = boosted_cpu_util(cpu); *util = min(*util, max_cap); *max = max_cap; } static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, unsigned int flags) { if (flags & SCHED_CPUFREQ_IOWAIT) { if (sg_cpu->iowait_boost_pending) return; sg_cpu->iowait_boost_pending = true; if (sg_cpu->iowait_boost) { sg_cpu->iowait_boost <<= 1; if (sg_cpu->iowait_boost > sg_cpu->iowait_boost_max) sg_cpu->iowait_boost = sg_cpu->iowait_boost_max; } else { sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->min; } } else if (sg_cpu->iowait_boost) { s64 delta_ns = time - sg_cpu->last_update; /* Clear iowait_boost if the CPU apprears to have been idle. */ if (delta_ns > TICK_NSEC) { sg_cpu->iowait_boost = 0; sg_cpu->iowait_boost_pending = false; } } } static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util, unsigned long *max) { unsigned int boost_util, boost_max; if (!sg_cpu->iowait_boost) return; if (sg_cpu->iowait_boost_pending) { sg_cpu->iowait_boost_pending = false; } else { sg_cpu->iowait_boost >>= 1; if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) { sg_cpu->iowait_boost = 0; return; } } boost_util = sg_cpu->iowait_boost; boost_max = sg_cpu->iowait_boost_max; if (*util * boost_max < *max * boost_util) { *util = boost_util; *max = boost_max; } } static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) { struct sugov_policy *sg_policy = sg_cpu->sg_policy; struct cpufreq_policy *policy = sg_policy->policy; unsigned long util = 0, max = 1; unsigned int j; for_each_cpu_and(j, policy->related_cpus, cpu_online_mask) { struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); unsigned long j_util, j_max; s64 delta_ns; /* * If the CPU utilization was last updated before the previous * frequency update and the time elapsed between the last update * of the CPU utilization and the last frequency update is long * enough, don't take the CPU into account as it probably is * idle now (and clear iowait_boost for it). */ delta_ns = time - j_sg_cpu->last_update; if (delta_ns > TICK_NSEC) { j_sg_cpu->iowait_boost = 0; j_sg_cpu->iowait_boost_pending = false; continue; } if (j_sg_cpu->flags & SCHED_CPUFREQ_DL) return policy->cpuinfo.max_freq; j_util = j_sg_cpu->util; j_max = j_sg_cpu->max; if (j_util * max > j_max * util) { util = j_util; max = j_max; } sugov_iowait_boost(j_sg_cpu, &util, &max); } return get_next_freq(sg_policy, util, max); } static void sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags) { struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); struct sugov_policy *sg_policy = sg_cpu->sg_policy; unsigned long util, max; unsigned int next_f; sugov_get_util(&util, &max, sg_cpu->cpu); raw_spin_lock(&sg_policy->update_lock); sg_cpu->util = util; sg_cpu->max = max; sg_cpu->flags = flags; sugov_set_iowait_boost(sg_cpu, time, flags); sg_cpu->last_update = time; if (sugov_should_update_freq(sg_policy, time)) { if (flags & SCHED_CPUFREQ_DL) next_f = sg_policy->policy->cpuinfo.max_freq; else next_f = sugov_next_freq_shared(sg_cpu, time); sugov_update_commit(sg_policy, time, next_f); } raw_spin_unlock(&sg_policy->update_lock); } static void sugov_work(struct kthread_work *work) { struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work); down_write(&sg_policy->policy->rwsem); mutex_lock(&sg_policy->work_lock); __cpufreq_driver_target(sg_policy->policy, sg_policy->next_freq, CPUFREQ_RELATION_L); mutex_unlock(&sg_policy->work_lock); up_write(&sg_policy->policy->rwsem); sg_policy->work_in_progress = false; } static void sugov_irq_work(struct irq_work *irq_work) { struct sugov_policy *sg_policy; sg_policy = container_of(irq_work, struct sugov_policy, irq_work); /* * For RT and deadline tasks, the schedutil governor shoots the * frequency to maximum. Special care must be taken to ensure that this * kthread doesn't result in the same behavior. * * This is (mostly) guaranteed by the work_in_progress flag. The flag is * updated only at the end of the sugov_work() function and before that * the schedutil governor rejects all other frequency scaling requests. * * There is a very rare case though, where the RT thread yields right * after the work_in_progress flag is cleared. The effects of that are * neglected for now. */ kthread_queue_work(&sg_policy->worker, &sg_policy->work); } /************************ Governor externals ***********************/ static void update_min_rate_limit_ns(struct sugov_policy *sg_policy); void sugov_update_rate_limit_us(struct cpufreq_policy *policy, int up_rate_limit_ms, int down_rate_limit_ms) { struct sugov_policy *sg_policy; struct sugov_tunables *tunables; sg_policy = policy->governor_data; if (!sg_policy) return; tunables = sg_policy->tunables; if (!tunables) return; tunables->up_rate_limit_us = (unsigned int)(up_rate_limit_ms * USEC_PER_MSEC); tunables->down_rate_limit_us = (unsigned int)(down_rate_limit_ms * USEC_PER_MSEC); sg_policy->up_rate_delay_ns = up_rate_limit_ms * NSEC_PER_MSEC; sg_policy->down_rate_delay_ns = down_rate_limit_ms * NSEC_PER_MSEC; update_min_rate_limit_ns(sg_policy); } int sugov_sysfs_add_attr(struct cpufreq_policy *policy, const struct attribute *attr) { struct sugov_policy *sg_policy; struct sugov_tunables *tunables; sg_policy = policy->governor_data; if (!sg_policy) return -ENODEV; tunables = sg_policy->tunables; if (!tunables) return -ENODEV; return sysfs_create_file(&tunables->attr_set.kobj, attr); } struct cpufreq_policy *sugov_get_attr_policy(struct gov_attr_set *attr_set) { struct sugov_policy *sg_policy = list_first_entry(&attr_set->policy_list, typeof(*sg_policy), tunables_hook); return sg_policy->policy; } /************************** sysfs interface ************************/ static struct sugov_tunables *global_tunables; static DEFINE_MUTEX(global_tunables_lock); static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set) { return container_of(attr_set, struct sugov_tunables, attr_set); } static DEFINE_MUTEX(min_rate_lock); static void update_min_rate_limit_ns(struct sugov_policy *sg_policy) { mutex_lock(&min_rate_lock); sg_policy->min_rate_limit_ns = min(sg_policy->up_rate_delay_ns, sg_policy->down_rate_delay_ns); mutex_unlock(&min_rate_lock); } static ssize_t up_rate_limit_us_show(struct gov_attr_set *attr_set, char *buf) { struct sugov_tunables *tunables = to_sugov_tunables(attr_set); return sprintf(buf, "%u\n", tunables->up_rate_limit_us); } static ssize_t down_rate_limit_us_show(struct gov_attr_set *attr_set, char *buf) { struct sugov_tunables *tunables = to_sugov_tunables(attr_set); return sprintf(buf, "%u\n", tunables->down_rate_limit_us); } static ssize_t up_rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct sugov_tunables *tunables = to_sugov_tunables(attr_set); struct sugov_policy *sg_policy; unsigned int rate_limit_us; if (kstrtouint(buf, 10, &rate_limit_us)) return -EINVAL; tunables->up_rate_limit_us = rate_limit_us; list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) { sg_policy->up_rate_delay_ns = rate_limit_us * NSEC_PER_USEC; update_min_rate_limit_ns(sg_policy); } return count; } static ssize_t down_rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count) { struct sugov_tunables *tunables = to_sugov_tunables(attr_set); struct sugov_policy *sg_policy; unsigned int rate_limit_us; if (kstrtouint(buf, 10, &rate_limit_us)) return -EINVAL; tunables->down_rate_limit_us = rate_limit_us; list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook) { sg_policy->down_rate_delay_ns = rate_limit_us * NSEC_PER_USEC; update_min_rate_limit_ns(sg_policy); } return count; } static struct governor_attr up_rate_limit_us = __ATTR_RW(up_rate_limit_us); static struct governor_attr down_rate_limit_us = __ATTR_RW(down_rate_limit_us); static struct attribute *sugov_attributes[] = { &up_rate_limit_us.attr, &down_rate_limit_us.attr, NULL }; static struct kobj_type sugov_tunables_ktype = { .default_attrs = sugov_attributes, .sysfs_ops = &governor_sysfs_ops, }; /********************** cpufreq governor interface *********************/ static struct cpufreq_governor schedutil_gov; static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy; sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL); if (!sg_policy) return NULL; sg_policy->policy = policy; raw_spin_lock_init(&sg_policy->update_lock); return sg_policy; } static void sugov_policy_free(struct sugov_policy *sg_policy) { kfree(sg_policy); } static int sugov_kthread_create(struct sugov_policy *sg_policy) { struct task_struct *thread; struct sched_param param = { .sched_priority = MAX_USER_RT_PRIO / 2 }; struct cpufreq_policy *policy = sg_policy->policy; int ret; /* kthread only required for slow path */ if (policy->fast_switch_enabled) return 0; kthread_init_work(&sg_policy->work, sugov_work); kthread_init_worker(&sg_policy->worker); thread = kthread_create(kthread_worker_fn, &sg_policy->worker, "sugov:%d", cpumask_first(policy->related_cpus)); if (IS_ERR(thread)) { pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread)); return PTR_ERR(thread); } ret = sched_setscheduler_nocheck(thread, SCHED_FIFO, ¶m); if (ret) { kthread_stop(thread); pr_warn("%s: failed to set SCHED_FIFO\n", __func__); return ret; } sg_policy->thread = thread; /* Kthread is bound to all CPUs by default */ if (!policy->dvfs_possible_from_any_cpu) kthread_bind_mask(thread, cpu_coregroup_mask(0)); init_irq_work(&sg_policy->irq_work, sugov_irq_work); mutex_init(&sg_policy->work_lock); wake_up_process(thread); return 0; } static void sugov_kthread_stop(struct sugov_policy *sg_policy) { /* kthread only required for slow path */ if (sg_policy->policy->fast_switch_enabled) return; kthread_flush_worker(&sg_policy->worker); kthread_stop(sg_policy->thread); mutex_destroy(&sg_policy->work_lock); } static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy) { struct sugov_tunables *tunables; tunables = kzalloc(sizeof(*tunables), GFP_KERNEL); if (tunables) { gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook); if (!have_governor_per_policy()) global_tunables = tunables; } return tunables; } static void sugov_tunables_free(struct sugov_tunables *tunables) { if (!have_governor_per_policy()) global_tunables = NULL; kfree(tunables); } static int sugov_init(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy; struct sugov_tunables *tunables; int ret = 0; /* State should be equivalent to EXIT */ if (policy->governor_data) return -EBUSY; cpufreq_enable_fast_switch(policy); /* restore saved sg_policy */ sg_policy = sugov_restore_policy(policy); if (sg_policy) goto tunables_init; sg_policy = sugov_policy_alloc(policy); if (!sg_policy) { ret = -ENOMEM; goto disable_fast_switch; } ret = sugov_kthread_create(sg_policy); if (ret) goto free_sg_policy; tunables_init: mutex_lock(&global_tunables_lock); if (global_tunables) { if (WARN_ON(have_governor_per_policy())) { ret = -EINVAL; goto stop_kthread; } policy->governor_data = sg_policy; sg_policy->tunables = global_tunables; gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook); goto out; } tunables = sugov_tunables_alloc(sg_policy); if (!tunables) { ret = -ENOMEM; goto stop_kthread; } tunables->up_rate_limit_us = cpufreq_policy_transition_delay_us(policy); tunables->down_rate_limit_us = cpufreq_policy_transition_delay_us(policy); policy->governor_data = sg_policy; sg_policy->tunables = tunables; ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype, get_governor_parent_kobj(policy), "%s", schedutil_gov.name); if (ret) goto fail; out: mutex_unlock(&global_tunables_lock); return 0; fail: policy->governor_data = NULL; sugov_tunables_free(tunables); stop_kthread: sugov_kthread_stop(sg_policy); free_sg_policy: mutex_unlock(&global_tunables_lock); sugov_policy_free(sg_policy); disable_fast_switch: cpufreq_disable_fast_switch(policy); pr_err("initialization failed (error %d)\n", ret); return ret; } static void sugov_exit(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy = policy->governor_data; struct sugov_tunables *tunables = sg_policy->tunables; unsigned int count; mutex_lock(&global_tunables_lock); count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook); policy->governor_data = NULL; if (!count) sugov_tunables_free(tunables); if (sugov_save_policy(sg_policy)) goto out; sugov_kthread_stop(sg_policy); sugov_policy_free(sg_policy); out: mutex_unlock(&global_tunables_lock); cpufreq_disable_fast_switch(policy); } static int sugov_start(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy = policy->governor_data; unsigned int cpu; sg_policy->up_rate_delay_ns = sg_policy->tunables->up_rate_limit_us * NSEC_PER_USEC; sg_policy->down_rate_delay_ns = sg_policy->tunables->down_rate_limit_us * NSEC_PER_USEC; update_min_rate_limit_ns(sg_policy); sg_policy->last_freq_update_time = 0; sg_policy->next_freq = UINT_MAX; sg_policy->work_in_progress = false; sg_policy->need_freq_update = false; sg_policy->cached_raw_freq = 0; for_each_cpu(cpu, policy->cpus) { struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); memset(sg_cpu, 0, sizeof(*sg_cpu)); sg_cpu->cpu = cpu; sg_cpu->sg_policy = sg_policy; sg_cpu->flags = 0; sugov_start_slack(cpu); sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; } for_each_cpu(cpu, policy->cpus) { struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, sugov_update_shared); } return 0; } static void sugov_stop(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy = policy->governor_data; unsigned int cpu; for_each_cpu(cpu, policy->cpus) { sugov_stop_slack(cpu); cpufreq_remove_update_util_hook(cpu); } synchronize_sched(); if (!policy->fast_switch_enabled) { irq_work_sync(&sg_policy->irq_work); } } static void sugov_limits(struct cpufreq_policy *policy) { struct sugov_policy *sg_policy = policy->governor_data; mutex_lock(&global_tunables_lock); if (!sg_policy) { mutex_unlock(&global_tunables_lock); return; } if (!policy->fast_switch_enabled) { mutex_lock(&sg_policy->work_lock); cpufreq_policy_apply_limits(policy); mutex_unlock(&sg_policy->work_lock); } sugov_update_min(policy); sg_policy->need_freq_update = true; mutex_unlock(&global_tunables_lock); } static struct cpufreq_governor schedutil_gov = { .name = "schedutil", .owner = THIS_MODULE, .dynamic_switching = true, .init = sugov_init, .exit = sugov_exit, .start = sugov_start, .stop = sugov_stop, .limits = sugov_limits, }; #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL struct cpufreq_governor *cpufreq_default_governor(void) { return &schedutil_gov; } #endif static void sugov_update_min(struct cpufreq_policy *policy) { int cpu, max_cap; struct sugov_exynos *sg_exynos; int min_cap; max_cap = arch_scale_cpu_capacity(NULL, policy->cpu); /* min_cap is minimum value making higher frequency than policy->min */ min_cap = max_cap * policy->min / policy->max; min_cap = (min_cap * 4 / 5) + 1; for_each_cpu(cpu, policy->cpus) { sg_exynos = &per_cpu(sugov_exynos, cpu); sg_exynos->min = min_cap; } } static void sugov_nop_timer(unsigned long data) { /* * The purpose of slack-timer is to wake up the CPU from IDLE, in order * to decrease its frequency if it is not set to minimum already. * * This is important for platforms where CPU with higher frequencies * consume higher power even at IDLE. */ trace_sugov_slack_func(smp_processor_id()); } static void sugov_start_slack(int cpu) { struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); if (!sg_exynos->enabled) return; sg_exynos->min = ULONG_MAX; sg_exynos->started = true; } static void sugov_stop_slack(int cpu) { struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); sg_exynos->started = false; if (timer_pending(&sg_exynos->timer)) del_timer_sync(&sg_exynos->timer); } static s64 get_next_event_time_ms(unsigned int cpu) { return ktime_to_us(ktime_sub(*(get_next_event_cpu(cpu)), ktime_get())); } static int sugov_need_slack_timer(unsigned int cpu) { struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); if (schedtune_cpu_boost(cpu)) return 0; if (sg_cpu->util > sg_exynos->min && get_next_event_time_ms(cpu) > sg_exynos->expired_time) return 1; return 0; } static int sugov_pm_notifier(struct notifier_block *self, unsigned long action, void *v) { unsigned int cpu = raw_smp_processor_id(); struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu); struct timer_list *timer = &sg_exynos->timer; if (!sg_exynos->started) return NOTIFY_OK; switch (action) { case CPU_PM_ENTER_PREPARE: if (timer_pending(timer)) del_timer_sync(timer); if (sugov_need_slack_timer(cpu)) { timer->expires = jiffies + msecs_to_jiffies(sg_exynos->expired_time); add_timer_on(timer, cpu); trace_sugov_slack(cpu, sg_cpu->util, sg_exynos->min, action, 1); } break; case CPU_PM_ENTER: if (timer_pending(timer) && !sugov_need_slack_timer(cpu)) { del_timer_sync(timer); trace_sugov_slack(cpu, sg_cpu->util, sg_exynos->min, action, -1); } break; case CPU_PM_EXIT_POST: if (timer_pending(timer) && (time_after(timer->expires, jiffies))) { del_timer_sync(timer); trace_sugov_slack(cpu, sg_cpu->util, sg_exynos->min, action, -1); } break; } return NOTIFY_OK; } static struct notifier_block sugov_pm_nb = { .notifier_call = sugov_pm_notifier, }; static int find_cpu_pm_qos_class(int pm_qos_class) { int cpu; for_each_possible_cpu(cpu) { struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); if ((sg_exynos->qos_min_class == pm_qos_class) && cpumask_test_cpu(cpu, cpu_active_mask)) return cpu; } pr_err("cannot find cpu of PM QoS class\n"); return -EINVAL; } static int sugov_pm_qos_callback(struct notifier_block *nb, unsigned long val, void *v) { struct sugov_cpu *sg_cpu; struct cpufreq_policy *policy; int pm_qos_class = *((int *)v); unsigned int next_freq; int cpu; cpu = find_cpu_pm_qos_class(pm_qos_class); if (cpu < 0) return NOTIFY_BAD; sg_cpu = &per_cpu(sugov_cpu, cpu); if (!sg_cpu || !sg_cpu->sg_policy || !sg_cpu->sg_policy->policy) return NOTIFY_BAD; next_freq = sg_cpu->sg_policy->next_freq; policy = cpufreq_cpu_get(cpu); if (!policy) return NOTIFY_BAD; if (val >= policy->cur) { cpufreq_cpu_put(policy); return NOTIFY_BAD; } cpufreq_driver_target(policy, next_freq, CPUFREQ_RELATION_L); cpufreq_cpu_put(policy); return NOTIFY_OK; } static struct notifier_block sugov_min_qos_notifier = { .notifier_call = sugov_pm_qos_callback, .priority = INT_MIN, }; static int __init sugov_parse_dt(struct device_node *dn, int cpu) { struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); /* parsing slack info */ if (of_property_read_u32(dn, "enabled", &sg_exynos->enabled)) return -EINVAL; if (sg_exynos->enabled) if (of_property_read_u32(dn, "expired_time", &sg_exynos->expired_time)) sg_exynos->expired_time = DEFAULT_EXPIRED_TIME; /* parsing pm_qos_class info */ if (of_property_read_u32(dn, "qos_min_class", &sg_exynos->qos_min_class)) return -EINVAL; return 0; } static void __init sugov_exynos_init(void) { int cpu, ret; struct device_node *dn = NULL; const char *buf; while ((dn = of_find_node_by_type(dn, "schedutil-domain"))) { struct cpumask shared_mask; /* Get shared cpus */ ret = of_property_read_string(dn, "shared-cpus", &buf); if (ret) goto exit; cpulist_parse(buf, &shared_mask); for_each_cpu(cpu, &shared_mask) if (sugov_parse_dt(dn, cpu)) goto exit; } for_each_possible_cpu(cpu) { struct sugov_exynos *sg_exynos = &per_cpu(sugov_exynos, cpu); if (!sg_exynos->enabled) continue; /* Initialize slack-timer */ init_timer_pinned(&sg_exynos->timer); sg_exynos->timer.function = sugov_nop_timer; } pm_qos_add_notifier(PM_QOS_CLUSTER0_FREQ_MIN, &sugov_min_qos_notifier); pm_qos_add_notifier(PM_QOS_CLUSTER1_FREQ_MIN, &sugov_min_qos_notifier); cpu_pm_register_notifier(&sugov_pm_nb); return; exit: pr_info("%s: failed to initialized slack_timer, pm_qos handler\n", __func__); } static int __init sugov_register(void) { sugov_exynos_init(); return cpufreq_register_governor(&schedutil_gov); } fs_initcall(sugov_register);