v4.19.13 snapshot.
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
new file mode 100644
index 0000000..3fffad3
--- /dev/null
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -0,0 +1,885 @@
+/*
+ * CPUFreq governor based on scheduler-provided CPU utilization data.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * 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 "sched.h"
+
+#include <trace/events/power.h>
+
+struct sugov_tunables {
+ struct gov_attr_set attr_set;
+ unsigned int 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 freq_update_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;
+
+ unsigned long bw_dl;
+ unsigned long max;
+
+ /* 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);
+
+/************************ Governor internals ***********************/
+
+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_this_cpu_can_update(sg_policy->policy))
+ return false;
+
+ if (unlikely(sg_policy->need_freq_update))
+ return true;
+
+ delta_ns = time - sg_policy->last_freq_update_time;
+
+ return delta_ns >= sg_policy->freq_update_delay_ns;
+}
+
+static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
+ unsigned int next_freq)
+{
+ if (sg_policy->next_freq == next_freq)
+ return false;
+
+ sg_policy->next_freq = next_freq;
+ sg_policy->last_freq_update_time = time;
+
+ return true;
+}
+
+static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
+ unsigned int next_freq)
+{
+ struct cpufreq_policy *policy = sg_policy->policy;
+
+ if (!sugov_update_next_freq(sg_policy, time, next_freq))
+ return;
+
+ 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());
+}
+
+static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,
+ unsigned int next_freq)
+{
+ if (!sugov_update_next_freq(sg_policy, time, next_freq))
+ return;
+
+ if (!sg_policy->work_in_progress) {
+ sg_policy->work_in_progress = true;
+ irq_work_queue(&sg_policy->irq_work);
+ }
+}
+
+/**
+ * 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->cpuinfo.max_freq : policy->cur;
+
+ freq = (freq + (freq >> 2)) * util / max;
+
+ if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
+ return sg_policy->next_freq;
+
+ sg_policy->need_freq_update = false;
+ sg_policy->cached_raw_freq = freq;
+ return cpufreq_driver_resolve_freq(policy, freq);
+}
+
+/*
+ * This function computes an effective utilization for the given CPU, to be
+ * used for frequency selection given the linear relation: f = u * f_max.
+ *
+ * The scheduler tracks the following metrics:
+ *
+ * cpu_util_{cfs,rt,dl,irq}()
+ * cpu_bw_dl()
+ *
+ * Where the cfs,rt and dl util numbers are tracked with the same metric and
+ * synchronized windows and are thus directly comparable.
+ *
+ * The cfs,rt,dl utilization are the running times measured with rq->clock_task
+ * which excludes things like IRQ and steal-time. These latter are then accrued
+ * in the irq utilization.
+ *
+ * The DL bandwidth number otoh is not a measured metric but a value computed
+ * based on the task model parameters and gives the minimal utilization
+ * required to meet deadlines.
+ */
+static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
+{
+ struct rq *rq = cpu_rq(sg_cpu->cpu);
+ unsigned long util, irq, max;
+
+ sg_cpu->max = max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
+ sg_cpu->bw_dl = cpu_bw_dl(rq);
+
+ if (rt_rq_is_runnable(&rq->rt))
+ return max;
+
+ /*
+ * Early check to see if IRQ/steal time saturates the CPU, can be
+ * because of inaccuracies in how we track these -- see
+ * update_irq_load_avg().
+ */
+ irq = cpu_util_irq(rq);
+ if (unlikely(irq >= max))
+ return max;
+
+ /*
+ * Because the time spend on RT/DL tasks is visible as 'lost' time to
+ * CFS tasks and we use the same metric to track the effective
+ * utilization (PELT windows are synchronized) we can directly add them
+ * to obtain the CPU's actual utilization.
+ */
+ util = cpu_util_cfs(rq);
+ util += cpu_util_rt(rq);
+
+ /*
+ * We do not make cpu_util_dl() a permanent part of this sum because we
+ * want to use cpu_bw_dl() later on, but we need to check if the
+ * CFS+RT+DL sum is saturated (ie. no idle time) such that we select
+ * f_max when there is no idle time.
+ *
+ * NOTE: numerical errors or stop class might cause us to not quite hit
+ * saturation when we should -- something for later.
+ */
+ if ((util + cpu_util_dl(rq)) >= max)
+ return max;
+
+ /*
+ * There is still idle time; further improve the number by using the
+ * irq metric. Because IRQ/steal time is hidden from the task clock we
+ * need to scale the task numbers:
+ *
+ * 1 - irq
+ * U' = irq + ------- * U
+ * max
+ */
+ util = scale_irq_capacity(util, irq, max);
+ util += irq;
+
+ /*
+ * Bandwidth required by DEADLINE must always be granted while, for
+ * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
+ * to gracefully reduce the frequency when no tasks show up for longer
+ * periods of time.
+ *
+ * Ideally we would like to set bw_dl as min/guaranteed freq and util +
+ * bw_dl as requested freq. However, cpufreq is not yet ready for such
+ * an interface. So, we only do the latter for now.
+ */
+ return min(max, util + sg_cpu->bw_dl);
+}
+
+/**
+ * sugov_iowait_reset() - Reset the IO boost status of a CPU.
+ * @sg_cpu: the sugov data for the CPU to boost
+ * @time: the update time from the caller
+ * @set_iowait_boost: true if an IO boost has been requested
+ *
+ * The IO wait boost of a task is disabled after a tick since the last update
+ * of a CPU. If a new IO wait boost is requested after more then a tick, then
+ * we enable the boost starting from the minimum frequency, which improves
+ * energy efficiency by ignoring sporadic wakeups from IO.
+ */
+static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time,
+ bool set_iowait_boost)
+{
+ s64 delta_ns = time - sg_cpu->last_update;
+
+ /* Reset boost only if a tick has elapsed since last request */
+ if (delta_ns <= TICK_NSEC)
+ return false;
+
+ sg_cpu->iowait_boost = set_iowait_boost
+ ? sg_cpu->sg_policy->policy->min : 0;
+ sg_cpu->iowait_boost_pending = set_iowait_boost;
+
+ return true;
+}
+
+/**
+ * sugov_iowait_boost() - Updates the IO boost status of a CPU.
+ * @sg_cpu: the sugov data for the CPU to boost
+ * @time: the update time from the caller
+ * @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait
+ *
+ * Each time a task wakes up after an IO operation, the CPU utilization can be
+ * boosted to a certain utilization which doubles at each "frequent and
+ * successive" wakeup from IO, ranging from the utilization of the minimum
+ * OPP to the utilization of the maximum OPP.
+ * To keep doubling, an IO boost has to be requested at least once per tick,
+ * otherwise we restart from the utilization of the minimum OPP.
+ */
+static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
+ unsigned int flags)
+{
+ bool set_iowait_boost = flags & SCHED_CPUFREQ_IOWAIT;
+
+ /* Reset boost if the CPU appears to have been idle enough */
+ if (sg_cpu->iowait_boost &&
+ sugov_iowait_reset(sg_cpu, time, set_iowait_boost))
+ return;
+
+ /* Boost only tasks waking up after IO */
+ if (!set_iowait_boost)
+ return;
+
+ /* Ensure boost doubles only one time at each request */
+ if (sg_cpu->iowait_boost_pending)
+ return;
+ sg_cpu->iowait_boost_pending = true;
+
+ /* Double the boost at each request */
+ 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;
+ return;
+ }
+
+ /* First wakeup after IO: start with minimum boost */
+ sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->min;
+}
+
+/**
+ * sugov_iowait_apply() - Apply the IO boost to a CPU.
+ * @sg_cpu: the sugov data for the cpu to boost
+ * @time: the update time from the caller
+ * @util: the utilization to (eventually) boost
+ * @max: the maximum value the utilization can be boosted to
+ *
+ * A CPU running a task which woken up after an IO operation can have its
+ * utilization boosted to speed up the completion of those IO operations.
+ * The IO boost value is increased each time a task wakes up from IO, in
+ * sugov_iowait_apply(), and it's instead decreased by this function,
+ * each time an increase has not been requested (!iowait_boost_pending).
+ *
+ * A CPU which also appears to have been idle for at least one tick has also
+ * its IO boost utilization reset.
+ *
+ * This mechanism is designed to boost high frequently IO waiting tasks, while
+ * being more conservative on tasks which does sporadic IO operations.
+ */
+static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
+ unsigned long *util, unsigned long *max)
+{
+ unsigned int boost_util, boost_max;
+
+ /* No boost currently required */
+ if (!sg_cpu->iowait_boost)
+ return;
+
+ /* Reset boost if the CPU appears to have been idle enough */
+ if (sugov_iowait_reset(sg_cpu, time, false))
+ return;
+
+ /*
+ * An IO waiting task has just woken up:
+ * allow to further double the boost value
+ */
+ if (sg_cpu->iowait_boost_pending) {
+ sg_cpu->iowait_boost_pending = false;
+ } else {
+ /*
+ * Otherwise: reduce the boost value and disable it when we
+ * reach the minimum.
+ */
+ sg_cpu->iowait_boost >>= 1;
+ if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) {
+ sg_cpu->iowait_boost = 0;
+ return;
+ }
+ }
+
+ /*
+ * Apply the current boost value: a CPU is boosted only if its current
+ * utilization is smaller then the current IO boost level.
+ */
+ 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;
+ }
+}
+
+#ifdef CONFIG_NO_HZ_COMMON
+static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
+{
+ unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);
+ bool ret = idle_calls == sg_cpu->saved_idle_calls;
+
+ sg_cpu->saved_idle_calls = idle_calls;
+ return ret;
+}
+#else
+static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
+#endif /* CONFIG_NO_HZ_COMMON */
+
+/*
+ * Make sugov_should_update_freq() ignore the rate limit when DL
+ * has increased the utilization.
+ */
+static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy)
+{
+ if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl)
+ sg_policy->need_freq_update = true;
+}
+
+static void sugov_update_single(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;
+ bool busy;
+
+ sugov_iowait_boost(sg_cpu, time, flags);
+ sg_cpu->last_update = time;
+
+ ignore_dl_rate_limit(sg_cpu, sg_policy);
+
+ if (!sugov_should_update_freq(sg_policy, time))
+ return;
+
+ busy = sugov_cpu_is_busy(sg_cpu);
+
+ util = sugov_get_util(sg_cpu);
+ max = sg_cpu->max;
+ sugov_iowait_apply(sg_cpu, time, &util, &max);
+ next_f = get_next_freq(sg_policy, util, max);
+ /*
+ * Do not reduce the frequency if the CPU has not been idle
+ * recently, as the reduction is likely to be premature then.
+ */
+ if (busy && next_f < sg_policy->next_freq) {
+ next_f = sg_policy->next_freq;
+
+ /* Reset cached freq as next_freq has changed */
+ sg_policy->cached_raw_freq = 0;
+ }
+
+ /*
+ * This code runs under rq->lock for the target CPU, so it won't run
+ * concurrently on two different CPUs for the same target and it is not
+ * necessary to acquire the lock in the fast switch case.
+ */
+ if (sg_policy->policy->fast_switch_enabled) {
+ sugov_fast_switch(sg_policy, time, next_f);
+ } else {
+ raw_spin_lock(&sg_policy->update_lock);
+ sugov_deferred_update(sg_policy, time, next_f);
+ raw_spin_unlock(&sg_policy->update_lock);
+ }
+}
+
+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(j, policy->cpus) {
+ struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j);
+ unsigned long j_util, j_max;
+
+ j_util = sugov_get_util(j_sg_cpu);
+ j_max = j_sg_cpu->max;
+ sugov_iowait_apply(j_sg_cpu, time, &j_util, &j_max);
+
+ if (j_util * max > j_max * util) {
+ util = j_util;
+ max = j_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 int next_f;
+
+ raw_spin_lock(&sg_policy->update_lock);
+
+ sugov_iowait_boost(sg_cpu, time, flags);
+ sg_cpu->last_update = time;
+
+ ignore_dl_rate_limit(sg_cpu, sg_policy);
+
+ if (sugov_should_update_freq(sg_policy, time)) {
+ next_f = sugov_next_freq_shared(sg_cpu, time);
+
+ if (sg_policy->policy->fast_switch_enabled)
+ sugov_fast_switch(sg_policy, time, next_f);
+ else
+ sugov_deferred_update(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);
+ unsigned int freq;
+ unsigned long flags;
+
+ /*
+ * Hold sg_policy->update_lock shortly to handle the case where:
+ * incase sg_policy->next_freq is read here, and then updated by
+ * sugov_deferred_update() just before work_in_progress is set to false
+ * here, we may miss queueing the new update.
+ *
+ * Note: If a work was queued after the update_lock is released,
+ * sugov_work() will just be called again by kthread_work code; and the
+ * request will be proceed before the sugov thread sleeps.
+ */
+ raw_spin_lock_irqsave(&sg_policy->update_lock, flags);
+ freq = sg_policy->next_freq;
+ sg_policy->work_in_progress = false;
+ raw_spin_unlock_irqrestore(&sg_policy->update_lock, flags);
+
+ mutex_lock(&sg_policy->work_lock);
+ __cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L);
+ mutex_unlock(&sg_policy->work_lock);
+}
+
+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);
+
+ kthread_queue_work(&sg_policy->worker, &sg_policy->work);
+}
+
+/************************** 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 ssize_t 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->rate_limit_us);
+}
+
+static ssize_t
+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->rate_limit_us = rate_limit_us;
+
+ list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook)
+ sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC;
+
+ return count;
+}
+
+static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
+
+static struct attribute *sugov_attributes[] = {
+ &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_attr attr = {
+ .size = sizeof(struct sched_attr),
+ .sched_policy = SCHED_DEADLINE,
+ .sched_flags = SCHED_FLAG_SUGOV,
+ .sched_nice = 0,
+ .sched_priority = 0,
+ /*
+ * Fake (unused) bandwidth; workaround to "fix"
+ * priority inheritance.
+ */
+ .sched_runtime = 1000000,
+ .sched_deadline = 10000000,
+ .sched_period = 10000000,
+ };
+ 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_setattr_nocheck(thread, &attr);
+ if (ret) {
+ kthread_stop(thread);
+ pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__);
+ return ret;
+ }
+
+ sg_policy->thread = thread;
+ kthread_bind_mask(thread, policy->related_cpus);
+ 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);
+
+ 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;
+
+ 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->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);
+ mutex_unlock(&global_tunables_lock);
+
+free_sg_policy:
+ 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);
+
+ mutex_unlock(&global_tunables_lock);
+
+ sugov_kthread_stop(sg_policy);
+ sugov_policy_free(sg_policy);
+ 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->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC;
+ sg_policy->last_freq_update_time = 0;
+ sg_policy->next_freq = 0;
+ 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->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,
+ policy_is_shared(policy) ?
+ sugov_update_shared :
+ sugov_update_single);
+ }
+ 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)
+ cpufreq_remove_update_util_hook(cpu);
+
+ synchronize_sched();
+
+ if (!policy->fast_switch_enabled) {
+ irq_work_sync(&sg_policy->irq_work);
+ kthread_cancel_work_sync(&sg_policy->work);
+ }
+}
+
+static void sugov_limits(struct cpufreq_policy *policy)
+{
+ struct sugov_policy *sg_policy = policy->governor_data;
+
+ if (!policy->fast_switch_enabled) {
+ mutex_lock(&sg_policy->work_lock);
+ cpufreq_policy_apply_limits(policy);
+ mutex_unlock(&sg_policy->work_lock);
+ }
+
+ sg_policy->need_freq_update = true;
+}
+
+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 int __init sugov_register(void)
+{
+ return cpufreq_register_governor(&schedutil_gov);
+}
+fs_initcall(sugov_register);