| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * CPUFreq governor based on scheduler-provided CPU utilization data. |
| * |
| * Copyright (C) 2016, Intel Corporation |
| * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| */ |
| |
| #define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8) |
| |
| 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; |
| 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 limits_changed; |
| 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; |
| u64 last_update; |
| |
| unsigned long util; |
| unsigned long bw_dl; |
| |
| /* 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. |
| * |
| * This is needed on the slow switching platforms too to prevent CPUs |
| * going offline from leaving stale IRQ work items behind. |
| */ |
| if (!cpufreq_this_cpu_can_update(sg_policy->policy)) |
| return false; |
| |
| if (unlikely(sg_policy->limits_changed)) { |
| sg_policy->limits_changed = false; |
| sg_policy->need_freq_update = true; |
| 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->need_freq_update) |
| sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); |
| else 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_deferred_update(struct sugov_policy *sg_policy) |
| { |
| 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; |
| |
| util = map_util_perf(util); |
| freq = map_util_freq(util, freq, max); |
| |
| if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) |
| return sg_policy->next_freq; |
| |
| sg_policy->cached_raw_freq = freq; |
| return cpufreq_driver_resolve_freq(policy, freq); |
| } |
| |
| static void sugov_get_util(struct sugov_cpu *sg_cpu) |
| { |
| struct rq *rq = cpu_rq(sg_cpu->cpu); |
| |
| sg_cpu->bw_dl = cpu_bw_dl(rq); |
| sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu), |
| FREQUENCY_UTIL, NULL); |
| } |
| |
| /** |
| * 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 IOWAIT_BOOST_MIN, 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 ? IOWAIT_BOOST_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 IOWAIT_BOOST_MIN 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 = |
| min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE); |
| return; |
| } |
| |
| /* First wakeup after IO: start with minimum boost */ |
| sg_cpu->iowait_boost = IOWAIT_BOOST_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 |
| * @max_cap: the max CPU capacity |
| * |
| * 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 max_cap) |
| { |
| unsigned long boost; |
| |
| /* 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; |
| |
| if (!sg_cpu->iowait_boost_pending) { |
| /* |
| * No boost pending; reduce the boost value. |
| */ |
| sg_cpu->iowait_boost >>= 1; |
| if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) { |
| sg_cpu->iowait_boost = 0; |
| return; |
| } |
| } |
| |
| sg_cpu->iowait_boost_pending = false; |
| |
| /* |
| * sg_cpu->util is already in capacity scale; convert iowait_boost |
| * into the same scale so we can compare. |
| */ |
| boost = (sg_cpu->iowait_boost * max_cap) >> SCHED_CAPACITY_SHIFT; |
| boost = uclamp_rq_util_with(cpu_rq(sg_cpu->cpu), boost, NULL); |
| if (sg_cpu->util < boost) |
| sg_cpu->util = boost; |
| } |
| |
| #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) |
| { |
| if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl) |
| sg_cpu->sg_policy->limits_changed = true; |
| } |
| |
| static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu, |
| u64 time, unsigned long max_cap, |
| unsigned int flags) |
| { |
| sugov_iowait_boost(sg_cpu, time, flags); |
| sg_cpu->last_update = time; |
| |
| ignore_dl_rate_limit(sg_cpu); |
| |
| if (!sugov_should_update_freq(sg_cpu->sg_policy, time)) |
| return false; |
| |
| sugov_get_util(sg_cpu); |
| sugov_iowait_apply(sg_cpu, time, max_cap); |
| |
| return true; |
| } |
| |
| static void sugov_update_single_freq(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 cached_freq = sg_policy->cached_raw_freq; |
| unsigned long max_cap; |
| unsigned int next_f; |
| |
| max_cap = arch_scale_cpu_capacity(sg_cpu->cpu); |
| |
| if (!sugov_update_single_common(sg_cpu, time, max_cap, flags)) |
| return; |
| |
| next_f = get_next_freq(sg_policy, sg_cpu->util, max_cap); |
| /* |
| * Do not reduce the frequency if the CPU has not been idle |
| * recently, as the reduction is likely to be premature then. |
| * |
| * Except when the rq is capped by uclamp_max. |
| */ |
| if (!uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)) && |
| sugov_cpu_is_busy(sg_cpu) && next_f < sg_policy->next_freq) { |
| next_f = sg_policy->next_freq; |
| |
| /* Restore cached freq as next_freq has changed */ |
| sg_policy->cached_raw_freq = cached_freq; |
| } |
| |
| if (!sugov_update_next_freq(sg_policy, time, next_f)) |
| return; |
| |
| /* |
| * 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) { |
| cpufreq_driver_fast_switch(sg_policy->policy, next_f); |
| } else { |
| raw_spin_lock(&sg_policy->update_lock); |
| sugov_deferred_update(sg_policy); |
| raw_spin_unlock(&sg_policy->update_lock); |
| } |
| } |
| |
| static void sugov_update_single_perf(struct update_util_data *hook, u64 time, |
| unsigned int flags) |
| { |
| struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util); |
| unsigned long prev_util = sg_cpu->util; |
| unsigned long max_cap; |
| |
| /* |
| * Fall back to the "frequency" path if frequency invariance is not |
| * supported, because the direct mapping between the utilization and |
| * the performance levels depends on the frequency invariance. |
| */ |
| if (!arch_scale_freq_invariant()) { |
| sugov_update_single_freq(hook, time, flags); |
| return; |
| } |
| |
| max_cap = arch_scale_cpu_capacity(sg_cpu->cpu); |
| |
| if (!sugov_update_single_common(sg_cpu, time, max_cap, flags)) |
| return; |
| |
| /* |
| * Do not reduce the target performance level if the CPU has not been |
| * idle recently, as the reduction is likely to be premature then. |
| * |
| * Except when the rq is capped by uclamp_max. |
| */ |
| if (!uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)) && |
| sugov_cpu_is_busy(sg_cpu) && sg_cpu->util < prev_util) |
| sg_cpu->util = prev_util; |
| |
| cpufreq_driver_adjust_perf(sg_cpu->cpu, map_util_perf(sg_cpu->bw_dl), |
| map_util_perf(sg_cpu->util), max_cap); |
| |
| sg_cpu->sg_policy->last_freq_update_time = time; |
| } |
| |
| 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_cap; |
| unsigned int j; |
| |
| max_cap = arch_scale_cpu_capacity(sg_cpu->cpu); |
| |
| for_each_cpu(j, policy->cpus) { |
| struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j); |
| |
| sugov_get_util(j_sg_cpu); |
| sugov_iowait_apply(j_sg_cpu, time, max_cap); |
| |
| util = max(j_sg_cpu->util, util); |
| } |
| |
| return get_next_freq(sg_policy, util, max_cap); |
| } |
| |
| 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); |
| |
| if (sugov_should_update_freq(sg_policy, time)) { |
| next_f = sugov_next_freq_shared(sg_cpu, time); |
| |
| if (!sugov_update_next_freq(sg_policy, time, next_f)) |
| goto unlock; |
| |
| if (sg_policy->policy->fast_switch_enabled) |
| cpufreq_driver_fast_switch(sg_policy->policy, next_f); |
| else |
| sugov_deferred_update(sg_policy); |
| } |
| unlock: |
| 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: |
| * in case 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_attrs[] = { |
| &rate_limit_us.attr, |
| NULL |
| }; |
| ATTRIBUTE_GROUPS(sugov); |
| |
| static void sugov_tunables_free(struct kobject *kobj) |
| { |
| struct gov_attr_set *attr_set = to_gov_attr_set(kobj); |
| |
| kfree(to_sugov_tunables(attr_set)); |
| } |
| |
| static const struct kobj_type sugov_tunables_ktype = { |
| .default_groups = sugov_groups, |
| .sysfs_ops = &governor_sysfs_ops, |
| .release = &sugov_tunables_free, |
| }; |
| |
| /********************** cpufreq governor interface *********************/ |
| |
| 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_clear_global_tunables(void) |
| { |
| if (!have_governor_per_policy()) |
| global_tunables = NULL; |
| } |
| |
| 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: |
| kobject_put(&tunables->attr_set.kobj); |
| policy->governor_data = NULL; |
| sugov_clear_global_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_clear_global_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; |
| void (*uu)(struct update_util_data *data, u64 time, unsigned int flags); |
| 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->limits_changed = false; |
| sg_policy->cached_raw_freq = 0; |
| |
| sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS); |
| |
| 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; |
| } |
| |
| if (policy_is_shared(policy)) |
| uu = sugov_update_shared; |
| else if (policy->fast_switch_enabled && cpufreq_driver_has_adjust_perf()) |
| uu = sugov_update_single_perf; |
| else |
| uu = sugov_update_single_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, uu); |
| } |
| 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_rcu(); |
| |
| 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->limits_changed = true; |
| } |
| |
| struct cpufreq_governor schedutil_gov = { |
| .name = "schedutil", |
| .owner = THIS_MODULE, |
| .flags = CPUFREQ_GOV_DYNAMIC_SWITCHING, |
| .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 |
| |
| cpufreq_governor_init(schedutil_gov); |
| |
| #ifdef CONFIG_ENERGY_MODEL |
| static void rebuild_sd_workfn(struct work_struct *work) |
| { |
| rebuild_sched_domains_energy(); |
| } |
| static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn); |
| |
| /* |
| * EAS shouldn't be attempted without sugov, so rebuild the sched_domains |
| * on governor changes to make sure the scheduler knows about it. |
| */ |
| void sched_cpufreq_governor_change(struct cpufreq_policy *policy, |
| struct cpufreq_governor *old_gov) |
| { |
| if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) { |
| /* |
| * When called from the cpufreq_register_driver() path, the |
| * cpu_hotplug_lock is already held, so use a work item to |
| * avoid nested locking in rebuild_sched_domains(). |
| */ |
| schedule_work(&rebuild_sd_work); |
| } |
| |
| } |
| #endif |