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, 20 insertions, 11 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 268566e..d98ff68 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2023,10 +2023,12 @@ static int cpufreq_init_governor(struct cpufreq_policy *policy)
 
 	pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
 
-	ret = policy->governor->governor(policy, CPUFREQ_GOV_POLICY_INIT);
-	if (ret) {
-		module_put(policy->governor->owner);
-		return ret;
+	if (policy->governor->init) {
+		ret = policy->governor->init(policy);
+		if (ret) {
+			module_put(policy->governor->owner);
+			return ret;
+		}
 	}
 
 	policy->governor->initialized++;
@@ -2040,7 +2042,8 @@ static void cpufreq_exit_governor(struct cpufreq_policy *policy)
 
 	pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
 
-	policy->governor->governor(policy, CPUFREQ_GOV_POLICY_EXIT);
+	if (policy->governor->exit)
+		policy->governor->exit(policy);
 
 	policy->governor->initialized--;
 	module_put(policy->governor->owner);
@@ -2061,11 +2064,15 @@ static int cpufreq_start_governor(struct cpufreq_policy *policy)
 	if (cpufreq_driver->get && !cpufreq_driver->setpolicy)
 		cpufreq_update_current_freq(policy);
 
-	ret = policy->governor->governor(policy, CPUFREQ_GOV_START);
-	if (ret)
-		return ret;
+	if (policy->governor->start) {
+		ret = policy->governor->start(policy);
+		if (ret)
+			return ret;
+	}
+
+	if (policy->governor->limits)
+		policy->governor->limits(policy);
 
-	policy->governor->governor(policy, CPUFREQ_GOV_LIMITS);
 	return 0;
 }
 
@@ -2076,7 +2083,8 @@ static void cpufreq_stop_governor(struct cpufreq_policy *policy)
 
 	pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
 
-	policy->governor->governor(policy, CPUFREQ_GOV_STOP);
+	if (policy->governor->stop)
+		policy->governor->stop(policy);
 }
 
 static void cpufreq_governor_limits(struct cpufreq_policy *policy)
@@ -2086,7 +2094,8 @@ static void cpufreq_governor_limits(struct cpufreq_policy *policy)
 
 	pr_debug("%s: for CPU %u\n", __func__, policy->cpu);
 
-	policy->governor->governor(policy, CPUFREQ_GOV_LIMITS);
+	if (policy->governor->limits)
+		policy->governor->limits(policy);
 }
 
 int cpufreq_register_governor(struct cpufreq_governor *governor)