1 files changed, 496 insertions, 235 deletions

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 29a397067ffa..0ab5f9d4bc59 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -1,70 +1,59 @@
+// 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>
- *
- * 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 <linux/cpufreq.h>
-#include <linux/kthread.h>
 #include <uapi/linux/sched/types.h>
-#include <linux/slab.h>
-#include <trace/events/power.h>
-
 #include "sched.h"
 
-#define SUGOV_KTHREAD_PRIORITY	50
+#define IOWAIT_BOOST_MIN	(SCHED_CAPACITY_SCALE / 8)
 
 struct sugov_tunables {
-	struct gov_attr_set attr_set;
-	unsigned int rate_limit_us;
+	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 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;
+	struct update_util_data	update_util;
+	struct sugov_policy	*sg_policy;
+	unsigned int		cpu;
 
-	unsigned long iowait_boost;
-	unsigned long iowait_boost_max;
-	u64 last_update;
+	bool			iowait_boost_pending;
+	unsigned int		iowait_boost;
+	u64			last_update;
 
-	/* The fields below are only needed when sharing a policy. */
-	unsigned long util;
-	unsigned long max;
-	unsigned int flags;
+	unsigned long		util;
+	unsigned long		bw_min;
 
-	/* The field below is for single-CPU policies only. */
+	/* The field below is for single-CPU policies only: */
 #ifdef CONFIG_NO_HZ_COMMON
-	unsigned long saved_idle_calls;
+	unsigned long		saved_idle_calls;
 #endif
 };
 
@@ -76,48 +65,110 @@ static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
 {
 	s64 delta_ns;
 
-	if (sg_policy->work_in_progress)
+	/*
+	 * 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->need_freq_update)) {
-		sg_policy->need_freq_update = false;
+	if (unlikely(READ_ONCE(sg_policy->limits_changed))) {
+		WRITE_ONCE(sg_policy->limits_changed, false);
+		sg_policy->need_freq_update = true;
+
 		/*
-		 * This happens when limits change, so forget the previous
-		 * next_freq value and force an update.
+		 * The above limits_changed update must occur before the reads
+		 * of policy limits in cpufreq_driver_resolve_freq() or a policy
+		 * limits update might be missed, so use a memory barrier to
+		 * ensure it.
+		 *
+		 * This pairs with the write memory barrier in sugov_limits().
 		 */
-		sg_policy->next_freq = UINT_MAX;
+		smp_mb();
+
+		return true;
+	} else if (sg_policy->need_freq_update) {
+		/* ignore_dl_rate_limit() wants a new frequency to be found. */
 		return true;
 	}
 
 	delta_ns = time - sg_policy->last_freq_update_time;
+
 	return delta_ns >= sg_policy->freq_update_delay_ns;
 }
 
-static void sugov_update_commit(struct sugov_policy *sg_policy, u64 time,
-				unsigned int next_freq)
+static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
+				   unsigned int next_freq)
 {
-	struct cpufreq_policy *policy = sg_policy->policy;
-
-	if (sg_policy->next_freq == next_freq)
-		return;
+	if (sg_policy->need_freq_update) {
+		sg_policy->need_freq_update = false;
+		/*
+		 * The policy limits have changed, but if the return value of
+		 * cpufreq_driver_resolve_freq() after applying the new limits
+		 * is still equal to the previously selected frequency, the
+		 * driver callback need not be invoked unless the driver
+		 * specifically wants that to happen on every update of the
+		 * policy limits.
+		 */
+		if (sg_policy->next_freq == next_freq &&
+		    !cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS))
+			return false;
+	} else if (sg_policy->next_freq == next_freq) {
+		return false;
+	}
 
 	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 == CPUFREQ_ENTRY_INVALID)
-			return;
+	return true;
+}
 
-		policy->cur = next_freq;
-		trace_cpu_frequency(next_freq, smp_processor_id());
-	} else {
+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_capacity_ref_freq - get the reference frequency that has been used to
+ * correlate frequency and compute capacity for a given cpufreq policy. We use
+ * the CPU managing it for the arch_scale_freq_ref() call in the function.
+ * @policy: the cpufreq policy of the CPU in question.
+ *
+ * Return: the reference CPU frequency to compute a capacity.
+ */
+static __always_inline
+unsigned long get_capacity_ref_freq(struct cpufreq_policy *policy)
+{
+	unsigned int freq = arch_scale_freq_ref(policy->cpu);
+
+	if (freq)
+		return freq;
+
+	if (arch_scale_freq_invariant())
+		return policy->cpuinfo.max_freq;
+
+	/*
+	 * Apply a 25% margin so that we select a higher frequency than
+	 * the current one before the CPU is fully busy:
+	 */
+	return policy->cur + (policy->cur >> 2);
+}
+
+/**
  * 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.
@@ -143,186 +194,375 @@ 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;
+	unsigned int freq;
 
-	freq = (freq + (freq >> 2)) * util / max;
+	freq = get_capacity_ref_freq(policy);
+	freq = map_util_freq(util, freq, max);
 
-	if (freq == sg_policy->cached_raw_freq && sg_policy->next_freq != UINT_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(unsigned long *util, unsigned long *max)
+unsigned long sugov_effective_cpu_perf(int cpu, unsigned long actual,
+				 unsigned long min,
+				 unsigned long max)
 {
-	struct rq *rq = this_rq();
-	unsigned long cfs_max;
+	/* Add dvfs headroom to actual utilization */
+	actual = map_util_perf(actual);
+	/* Actually we don't need to target the max performance */
+	if (actual < max)
+		max = actual;
 
-	cfs_max = arch_scale_cpu_capacity(NULL, smp_processor_id());
+	/*
+	 * Ensure at least minimum performance while providing more compute
+	 * capacity when possible.
+	 */
+	return max(min, max);
+}
 
-	*util = min(rq->cfs.avg.util_avg, cfs_max);
-	*max = cfs_max;
+static void sugov_get_util(struct sugov_cpu *sg_cpu, unsigned long boost)
+{
+	unsigned long min, max, util = scx_cpuperf_target(sg_cpu->cpu);
+
+	if (!scx_switched_all())
+		util += cpu_util_cfs_boost(sg_cpu->cpu);
+	util = effective_cpu_util(sg_cpu->cpu, util, &min, &max);
+	util = max(util, boost);
+	sg_cpu->bw_min = min;
+	sg_cpu->util = sugov_effective_cpu_perf(sg_cpu->cpu, util, min, max);
 }
 
-static void sugov_set_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
-				   unsigned int flags)
+/**
+ * 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)
 {
-	if (flags & SCHED_CPUFREQ_IOWAIT) {
-		sg_cpu->iowait_boost = sg_cpu->iowait_boost_max;
-	} else if (sg_cpu->iowait_boost) {
-		s64 delta_ns = time - sg_cpu->last_update;
+	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;
-	}
+	/* 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;
 }
 
-static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, unsigned long *util,
-			       unsigned long *max)
+/**
+ * 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)
 {
-	unsigned long boost_util = sg_cpu->iowait_boost;
-	unsigned long boost_max = sg_cpu->iowait_boost_max;
+	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;
 
-	if (!boost_util)
+	/* Ensure boost doubles only one time at each request */
+	if (sg_cpu->iowait_boost_pending)
 		return;
+	sg_cpu->iowait_boost_pending = true;
 
-	if (*util * boost_max < *max * boost_util) {
-		*util = boost_util;
-		*max = boost_max;
+	/* 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;
 	}
-	sg_cpu->iowait_boost >>= 1;
+
+	/* 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 unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
+			       unsigned long max_cap)
+{
+	/* No boost currently required */
+	if (!sg_cpu->iowait_boost)
+		return 0;
+
+	/* Reset boost if the CPU appears to have been idle enough */
+	if (sugov_iowait_reset(sg_cpu, time, false))
+		return 0;
+
+	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 0;
+		}
+	}
+
+	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.
+	 */
+	return (sg_cpu->iowait_boost * max_cap) >> SCHED_CAPACITY_SHIFT;
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
-static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
+static bool sugov_hold_freq(struct sugov_cpu *sg_cpu)
 {
-	unsigned long idle_calls = tick_nohz_get_idle_calls();
-	bool ret = idle_calls == sg_cpu->saved_idle_calls;
+	unsigned long idle_calls;
+	bool ret;
+
+	/*
+	 * The heuristics in this function is for the fair class. For SCX, the
+	 * performance target comes directly from the BPF scheduler. Let's just
+	 * follow it.
+	 */
+	if (scx_switched_all())
+		return false;
+
+	/* if capped by uclamp_max, always update to be in compliance */
+	if (uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)))
+		return false;
+
+	/*
+	 * Maintain the frequency if the CPU has not been idle recently, as
+	 * reduction is likely to be premature.
+	 */
+	idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);
+	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 */
+#else /* !CONFIG_NO_HZ_COMMON: */
+static inline bool sugov_hold_freq(struct sugov_cpu *sg_cpu) { return false; }
+#endif /* !CONFIG_NO_HZ_COMMON */
 
-static void sugov_update_single(struct update_util_data *hook, u64 time,
-				unsigned int flags)
+/*
+ * 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_min)
+		sg_cpu->sg_policy->need_freq_update = true;
+}
+
+static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu,
+					      u64 time, unsigned long max_cap,
+					      unsigned int flags)
+{
+	unsigned long boost;
+
+	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;
+
+	boost = sugov_iowait_apply(sg_cpu, time, max_cap);
+	sugov_get_util(sg_cpu, boost);
+
+	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;
-	struct cpufreq_policy *policy = sg_policy->policy;
-	unsigned long util, max;
+	unsigned int cached_freq = sg_policy->cached_raw_freq;
+	unsigned long max_cap;
 	unsigned int next_f;
-	bool busy;
 
-	sugov_set_iowait_boost(sg_cpu, time, flags);
-	sg_cpu->last_update = time;
+	max_cap = arch_scale_cpu_capacity(sg_cpu->cpu);
 
-	if (!sugov_should_update_freq(sg_policy, time))
+	if (!sugov_update_single_common(sg_cpu, time, max_cap, flags))
 		return;
 
-	busy = sugov_cpu_is_busy(sg_cpu);
+	next_f = get_next_freq(sg_policy, sg_cpu->util, max_cap);
+
+	if (sugov_hold_freq(sg_cpu) && next_f < sg_policy->next_freq &&
+	    !sg_policy->need_freq_update) {
+		next_f = sg_policy->next_freq;
 
-	if (flags & SCHED_CPUFREQ_RT_DL) {
-		next_f = policy->cpuinfo.max_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 {
-		sugov_get_util(&util, &max);
-		sugov_iowait_boost(sg_cpu, &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;
+		raw_spin_lock(&sg_policy->update_lock);
+		sugov_deferred_update(sg_policy);
+		raw_spin_unlock(&sg_policy->update_lock);
 	}
-	sugov_update_commit(sg_policy, time, next_f);
+}
+
+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;
+
+	if (sugov_hold_freq(sg_cpu) && sg_cpu->util < prev_util)
+		sg_cpu->util = prev_util;
+
+	cpufreq_driver_adjust_perf(sg_cpu->cpu, sg_cpu->bw_min,
+				   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 = 1;
+	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);
-		unsigned long j_util, j_max;
-		s64 delta_ns;
+		unsigned long boost;
 
-		/*
-		 * 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;
-			continue;
-		}
-		if (j_sg_cpu->flags & SCHED_CPUFREQ_RT_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;
-		}
+		boost = sugov_iowait_apply(j_sg_cpu, time, max_cap);
+		sugov_get_util(j_sg_cpu, boost);
 
-		sugov_iowait_boost(j_sg_cpu, &util, &max);
+		util = max(j_sg_cpu->util, util);
 	}
 
-	return get_next_freq(sg_policy, util, max);
+	return get_next_freq(sg_policy, util, max_cap);
 }
 
-static void sugov_update_shared(struct update_util_data *hook, u64 time,
-				unsigned int flags)
+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);
-
 	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);
+	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)) {
-		if (flags & SCHED_CPUFREQ_RT_DL)
-			next_f = sg_policy->policy->cpuinfo.max_freq;
-		else
-			next_f = sugov_next_freq_shared(sg_cpu, time);
+		next_f = sugov_next_freq_shared(sg_cpu, time);
 
-		sugov_update_commit(sg_policy, time, next_f);
-	}
+		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, sg_policy->next_freq,
-				CPUFREQ_RELATION_L);
+	__cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L);
 	mutex_unlock(&sg_policy->work_lock);
-
-	sg_policy->work_in_progress = false;
 }
 
 static void sugov_irq_work(struct irq_work *irq_work)
@@ -331,19 +571,6 @@ static void sugov_irq_work(struct irq_work *irq_work)
 
 	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);
 }
 
@@ -364,8 +591,8 @@ static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf)
 	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)
+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;
@@ -384,14 +611,23 @@ static ssize_t rate_limit_us_store(struct gov_attr_set *attr_set, const char *bu
 
 static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
 
-static struct attribute *sugov_attributes[] = {
+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 struct kobj_type sugov_tunables_ktype = {
-	.default_attrs = sugov_attributes,
+static const struct kobj_type sugov_tunables_ktype = {
+	.default_groups = sugov_groups,
 	.sysfs_ops = &governor_sysfs_ops,
+	.release = &sugov_tunables_free,
 };
 
 /********************** cpufreq governor interface *********************/
@@ -419,7 +655,20 @@ static void sugov_policy_free(struct sugov_policy *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 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	= NSEC_PER_MSEC,
+		.sched_deadline = 10 * NSEC_PER_MSEC,
+		.sched_period	= 10 * NSEC_PER_MSEC,
+	};
 	struct cpufreq_policy *policy = sg_policy->policy;
 	int ret;
 
@@ -437,15 +686,19 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy)
 		return PTR_ERR(thread);
 	}
 
-	ret = sched_setscheduler_nocheck(thread, SCHED_FIFO, &param);
+	ret = sched_setattr_nocheck(thread, &attr);
 	if (ret) {
 		kthread_stop(thread);
-		pr_warn("%s: failed to set SCHED_FIFO\n", __func__);
+		pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__);
 		return ret;
 	}
 
 	sg_policy->thread = thread;
-	kthread_bind_mask(thread, policy->related_cpus);
+	if (policy->dvfs_possible_from_any_cpu)
+		set_cpus_allowed_ptr(thread, policy->related_cpus);
+	else
+		kthread_bind_mask(thread, policy->related_cpus);
+
 	init_irq_work(&sg_policy->irq_work, sugov_irq_work);
 	mutex_init(&sg_policy->work_lock);
 
@@ -478,12 +731,10 @@ static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_polic
 	return tunables;
 }
 
-static void sugov_tunables_free(struct sugov_tunables *tunables)
+static void sugov_clear_global_tunables(void)
 {
 	if (!have_governor_per_policy())
 		global_tunables = NULL;
-
-	kfree(tunables);
 }
 
 static int sugov_init(struct cpufreq_policy *policy)
@@ -528,16 +779,7 @@ static int sugov_init(struct cpufreq_policy *policy)
 		goto stop_kthread;
 	}
 
-	if (policy->transition_delay_us) {
-		tunables->rate_limit_us = policy->transition_delay_us;
-	} else {
-		unsigned int lat;
-
-		tunables->rate_limit_us = LATENCY_MULTIPLIER;
-		lat = policy->cpuinfo.transition_latency / NSEC_PER_USEC;
-		if (lat)
-			tunables->rate_limit_us *= lat;
-	}
+	tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy);
 
 	policy->governor_data = sg_policy;
 	sg_policy->tunables = tunables;
@@ -549,19 +791,24 @@ static int sugov_init(struct cpufreq_policy *policy)
 		goto fail;
 
 out:
+	/*
+	 * Schedutil is the preferred governor for EAS, so rebuild sched domains
+	 * on governor changes to make sure the scheduler knows about them.
+	 */
+	em_rebuild_sched_domains();
 	mutex_unlock(&global_tunables_lock);
 	return 0;
 
 fail:
+	kobject_put(&tunables->attr_set.kobj);
 	policy->governor_data = NULL;
-	sugov_tunables_free(tunables);
+	sugov_clear_global_tunables();
 
 stop_kthread:
 	sugov_kthread_stop(sg_policy);
-
-free_sg_policy:
 	mutex_unlock(&global_tunables_lock);
 
+free_sg_policy:
 	sugov_policy_free(sg_policy);
 
 disable_fast_switch:
@@ -582,43 +829,46 @@ static void sugov_exit(struct cpufreq_policy *policy)
 	count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
 	policy->governor_data = NULL;
 	if (!count)
-		sugov_tunables_free(tunables);
+		sugov_clear_global_tunables();
 
 	mutex_unlock(&global_tunables_lock);
 
 	sugov_kthread_stop(sg_policy);
 	sugov_policy_free(sg_policy);
 	cpufreq_disable_fast_switch(policy);
+
+	em_rebuild_sched_domains();
 }
 
 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 = UINT_MAX;
-	sg_policy->work_in_progress = false;
-	sg_policy->need_freq_update = false;
-	sg_policy->cached_raw_freq = 0;
+	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;
 
-	for_each_cpu(cpu, policy->cpus) {
-		struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
+	sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
 
-		memset(sg_cpu, 0, sizeof(*sg_cpu));
-		sg_cpu->sg_policy = sg_policy;
-		sg_cpu->flags = SCHED_CPUFREQ_RT;
-		sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq;
-	}
+	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,
-					     policy_is_shared(policy) ?
-							sugov_update_shared :
-							sugov_update_single);
+		memset(sg_cpu, 0, sizeof(*sg_cpu));
+		sg_cpu->cpu = cpu;
+		sg_cpu->sg_policy = sg_policy;
+		cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, uu);
 	}
 	return 0;
 }
@@ -631,7 +881,7 @@ static void sugov_stop(struct cpufreq_policy *policy)
 	for_each_cpu(cpu, policy->cpus)
 		cpufreq_remove_update_util_hook(cpu);
 
-	synchronize_sched();
+	synchronize_rcu();
 
 	if (!policy->fast_switch_enabled) {
 		irq_work_sync(&sg_policy->irq_work);
@@ -649,17 +899,27 @@ static void sugov_limits(struct cpufreq_policy *policy)
 		mutex_unlock(&sg_policy->work_lock);
 	}
 
-	sg_policy->need_freq_update = true;
+	/*
+	 * The limits_changed update below must take place before the updates
+	 * of policy limits in cpufreq_set_policy() or a policy limits update
+	 * might be missed, so use a memory barrier to ensure it.
+	 *
+	 * This pairs with the memory barrier in sugov_should_update_freq().
+	 */
+	smp_wmb();
+
+	WRITE_ONCE(sg_policy->limits_changed, true);
 }
 
 static struct cpufreq_governor schedutil_gov = {
-	.name = "schedutil",
-	.owner = THIS_MODULE,
-	.init = sugov_init,
-	.exit = sugov_exit,
-	.start = sugov_start,
-	.stop = sugov_stop,
-	.limits = sugov_limits,
+	.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
@@ -669,8 +929,9 @@ struct cpufreq_governor *cpufreq_default_governor(void)
 }
 #endif
 
-static int __init sugov_register(void)
+bool sugov_is_governor(struct cpufreq_policy *policy)
 {
-	return cpufreq_register_governor(&schedutil_gov);
+	return policy->governor == &schedutil_gov;
 }
-fs_initcall(sugov_register);
+
+cpufreq_governor_init(schedutil_gov);