cpufreq: governor: Get rid of governor events

The design of the cpufreq governor API is not very straightforward,
as struct cpufreq_governor provides only one callback to be invoked
from different code paths for different purposes.  The purpose it is
invoked for is determined by its second "event" argument, causing it
to act as a "callback multiplexer" of sorts.

Unfortunately, that leads to extra complexity in governors, some of
which implement the ->governor() callback as a switch statement
that simply checks the event argument and invokes a separate function
to handle that specific event.

That extra complexity can be eliminated by replacing the all-purpose
->governor() callback with a family of callbacks to carry out specific
governor operations: initialization and exit, start and stop and policy
limits updates.  That also turns out to reduce the code size too, so
do it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

1 files changed, 8 insertions, 26 deletions

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 14c4aa2..fdcee3c 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -394,7 +394,7 @@ static int sugov_init(struct cpufreq_policy *policy)
 	return ret;
 }
 
-static int sugov_exit(struct cpufreq_policy *policy)
+static void sugov_exit(struct cpufreq_policy *policy)
 {
 	struct sugov_policy *sg_policy = policy->governor_data;
 	struct sugov_tunables *tunables = sg_policy->tunables;
@@ -412,7 +412,6 @@ static int sugov_exit(struct cpufreq_policy *policy)
 	mutex_unlock(&global_tunables_lock);
 
 	sugov_policy_free(sg_policy);
-	return 0;
 }
 
 static int sugov_start(struct cpufreq_policy *policy)
@@ -444,7 +443,7 @@ static int sugov_start(struct cpufreq_policy *policy)
 	return 0;
 }
 
-static int sugov_stop(struct cpufreq_policy *policy)
+static void sugov_stop(struct cpufreq_policy *policy)
 {
 	struct sugov_policy *sg_policy = policy->governor_data;
 	unsigned int cpu;
@@ -456,10 +455,9 @@ static int sugov_stop(struct cpufreq_policy *policy)
 
 	irq_work_sync(&sg_policy->irq_work);
 	cancel_work_sync(&sg_policy->work);
-	return 0;
 }
 
-static int sugov_limits(struct cpufreq_policy *policy)
+static void sugov_limits(struct cpufreq_policy *policy)
 {
 	struct sugov_policy *sg_policy = policy->governor_data;
 
@@ -477,32 +475,16 @@ static int sugov_limits(struct cpufreq_policy *policy)
 	}
 
 	sg_policy->need_freq_update = true;
-	return 0;
-}
-
-int sugov_governor(struct cpufreq_policy *policy, unsigned int event)
-{
-	if (event == CPUFREQ_GOV_POLICY_INIT) {
-		return sugov_init(policy);
-	} else if (policy->governor_data) {
-		switch (event) {
-		case CPUFREQ_GOV_POLICY_EXIT:
-			return sugov_exit(policy);
-		case CPUFREQ_GOV_START:
-			return sugov_start(policy);
-		case CPUFREQ_GOV_STOP:
-			return sugov_stop(policy);
-		case CPUFREQ_GOV_LIMITS:
-			return sugov_limits(policy);
-		}
-	}
-	return -EINVAL;
 }
 
 static struct cpufreq_governor schedutil_gov = {
 	.name = "schedutil",
-	.governor = sugov_governor,
 	.owner = THIS_MODULE,
+	.init = sugov_init,
+	.exit = sugov_exit,
+	.start = sugov_start,
+	.stop = sugov_stop,
+	.limits = sugov_limits,
 };
 
 static int __init sugov_module_init(void)