cpufreq: Perform light-weight init/teardown during suspend/resume

Now that we have the infrastructure to perform a light-weight init/tear-down,
use that in the cpufreq CPU hotplug notifier when invoked from the
suspend/resume path.

This also ensures that the file permissions of the cpufreq sysfs files are
preserved across suspend/resume, something which commit a66b2e (cpufreq:
Preserve sysfs files across suspend/resume) originally intended to do, but
had to be reverted due to other problems.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/cpufreq.c

@@ -2040,22 +2040,26 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb,
 {
 	unsigned int cpu = (unsigned long)hcpu;
 	struct device *dev;
+	bool frozen = false;
 
 	dev = get_cpu_device(cpu);
 	if (dev) {
-		switch (action) {
+
+		if (action & CPU_TASKS_FROZEN)
+			frozen = true;
+
+		switch (action & ~CPU_TASKS_FROZEN) {
 		case CPU_ONLINE:
-		case CPU_ONLINE_FROZEN:
-			cpufreq_add_dev(dev, NULL);
+			__cpufreq_add_dev(dev, NULL, frozen);
 			cpufreq_update_policy(cpu);
 			break;
+
 		case CPU_DOWN_PREPARE:
-		case CPU_DOWN_PREPARE_FROZEN:
-			__cpufreq_remove_dev(dev, NULL, false);
+			__cpufreq_remove_dev(dev, NULL, frozen);
 			break;
+
 		case CPU_DOWN_FAILED:
-		case CPU_DOWN_FAILED_FROZEN:
-			cpufreq_add_dev(dev, NULL);
+			__cpufreq_add_dev(dev, NULL, frozen);
 			break;
 		}
 	}

drivers/cpufreq/cpufreq_stats.c

@@ -349,11 +349,9 @@ static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
 
 	switch (action) {
 	case CPU_DOWN_PREPARE:
-	case CPU_DOWN_PREPARE_FROZEN:
 		cpufreq_stats_free_sysfs(cpu);
 		break;
 	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
 		cpufreq_stats_free_table(cpu);
 		break;
 	}