cpufreq: schedutil: irq-work and mutex are only used in slow path

Execute the irq-work specific initialization/exit code only when the
fast path isn't available.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/sched/cpufreq_schedutil.c

@@ -390,15 +390,12 @@ static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
 		return NULL;
 
 	sg_policy->policy = policy;
-	init_irq_work(&sg_policy->irq_work, sugov_irq_work);
-	mutex_init(&sg_policy->work_lock);
 	raw_spin_lock_init(&sg_policy->update_lock);
 	return sg_policy;
 }
 
 static void sugov_policy_free(struct sugov_policy *sg_policy)
 {
-	mutex_destroy(&sg_policy->work_lock);
 	kfree(sg_policy);
 }
 
@@ -432,6 +429,9 @@ static int sugov_kthread_create(struct sugov_policy *sg_policy)
 
 	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;
@@ -445,6 +445,7 @@ static void sugov_kthread_stop(struct sugov_policy *sg_policy)
 
 	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)
@@ -611,8 +612,10 @@ static void sugov_stop(struct cpufreq_policy *policy)
 
 	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)