1 files changed, 48 insertions, 61 deletions

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 4cf0d28..5793e14 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -151,44 +151,36 @@ static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
 	return -1;
 }
 
-/* should be called late in the CPU removal sequence so that the stats
- * memory is still available in case someone tries to use it.
- */
-static void cpufreq_stats_free_table(unsigned int cpu)
+static void __cpufreq_stats_free_table(struct cpufreq_policy *policy)
 {
-	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
+	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, policy->cpu);
 
-	if (stat) {
-		pr_debug("%s: Free stat table\n", __func__);
-		kfree(stat->time_in_state);
-		kfree(stat);
-		per_cpu(cpufreq_stats_table, cpu) = NULL;
-	}
+	if (!stat)
+		return;
+
+	pr_debug("%s: Free stat table\n", __func__);
+
+	sysfs_remove_group(&policy->kobj, &stats_attr_group);
+	kfree(stat->time_in_state);
+	kfree(stat);
+	per_cpu(cpufreq_stats_table, policy->cpu) = NULL;
 }
 
-/* must be called early in the CPU removal sequence (before
- * cpufreq_remove_dev) so that policy is still valid.
- */
-static void cpufreq_stats_free_sysfs(unsigned int cpu)
+static void cpufreq_stats_free_table(unsigned int cpu)
 {
-	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
+	struct cpufreq_policy *policy;
 
+	policy = cpufreq_cpu_get(cpu);
 	if (!policy)
 		return;
 
-	if (!cpufreq_frequency_get_table(cpu))
-		goto put_ref;
-
-	if (!policy_is_shared(policy)) {
-		pr_debug("%s: Free sysfs stat\n", __func__);
-		sysfs_remove_group(&policy->kobj, &stats_attr_group);
-	}
+	if (cpufreq_frequency_get_table(policy->cpu))
+		__cpufreq_stats_free_table(policy);
 
-put_ref:
 	cpufreq_cpu_put(policy);
 }
 
-static int cpufreq_stats_create_table(struct cpufreq_policy *policy,
+static int __cpufreq_stats_create_table(struct cpufreq_policy *policy,
 		struct cpufreq_frequency_table *table)
 {
 	unsigned int i, j, count = 0, ret = 0;
@@ -261,6 +253,26 @@ error_get_fail:
 	return ret;
 }
 
+static void cpufreq_stats_create_table(unsigned int cpu)
+{
+	struct cpufreq_policy *policy;
+	struct cpufreq_frequency_table *table;
+
+	/*
+	 * "likely(!policy)" because normally cpufreq_stats will be registered
+	 * before cpufreq driver
+	 */
+	policy = cpufreq_cpu_get(cpu);
+	if (likely(!policy))
+		return;
+
+	table = cpufreq_frequency_get_table(policy->cpu);
+	if (likely(table))
+		__cpufreq_stats_create_table(policy, table);
+
+	cpufreq_cpu_put(policy);
+}
+
 static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
 {
 	struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table,
@@ -277,7 +289,7 @@ static void cpufreq_stats_update_policy_cpu(struct cpufreq_policy *policy)
 static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
 		unsigned long val, void *data)
 {
-	int ret;
+	int ret = 0;
 	struct cpufreq_policy *policy = data;
 	struct cpufreq_frequency_table *table;
 	unsigned int cpu = policy->cpu;
@@ -287,15 +299,16 @@ static int cpufreq_stat_notifier_policy(struct notifier_block *nb,
 		return 0;
 	}
 
-	if (val != CPUFREQ_NOTIFY)
-		return 0;
 	table = cpufreq_frequency_get_table(cpu);
 	if (!table)
 		return 0;
-	ret = cpufreq_stats_create_table(policy, table);
-	if (ret)
-		return ret;
-	return 0;
+
+	if (val == CPUFREQ_CREATE_POLICY)
+		ret = __cpufreq_stats_create_table(policy, table);
+	else if (val == CPUFREQ_REMOVE_POLICY)
+		__cpufreq_stats_free_table(policy);
+
+	return ret;
 }
 
 static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
@@ -334,29 +347,6 @@ static int cpufreq_stat_notifier_trans(struct notifier_block *nb,
 	return 0;
 }
 
-static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
-					       unsigned long action,
-					       void *hcpu)
-{
-	unsigned int cpu = (unsigned long)hcpu;
-
-	switch (action) {
-	case CPU_DOWN_PREPARE:
-		cpufreq_stats_free_sysfs(cpu);
-		break;
-	case CPU_DEAD:
-		cpufreq_stats_free_table(cpu);
-		break;
-	}
-	return NOTIFY_OK;
-}
-
-/* priority=1 so this will get called before cpufreq_remove_dev */
-static struct notifier_block cpufreq_stat_cpu_notifier __refdata = {
-	.notifier_call = cpufreq_stat_cpu_callback,
-	.priority = 1,
-};
-
 static struct notifier_block notifier_policy_block = {
 	.notifier_call = cpufreq_stat_notifier_policy
 };
@@ -376,14 +366,14 @@ static int __init cpufreq_stats_init(void)
 	if (ret)
 		return ret;
 
-	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
+	for_each_online_cpu(cpu)
+		cpufreq_stats_create_table(cpu);
 
 	ret = cpufreq_register_notifier(&notifier_trans_block,
 				CPUFREQ_TRANSITION_NOTIFIER);
 	if (ret) {
 		cpufreq_unregister_notifier(&notifier_policy_block,
 				CPUFREQ_POLICY_NOTIFIER);
-		unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
 		for_each_online_cpu(cpu)
 			cpufreq_stats_free_table(cpu);
 		return ret;
@@ -399,11 +389,8 @@ static void __exit cpufreq_stats_exit(void)
 			CPUFREQ_POLICY_NOTIFIER);
 	cpufreq_unregister_notifier(&notifier_trans_block,
 			CPUFREQ_TRANSITION_NOTIFIER);
-	unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
-	for_each_online_cpu(cpu) {
+	for_each_online_cpu(cpu)
 		cpufreq_stats_free_table(cpu);
-		cpufreq_stats_free_sysfs(cpu);
-	}
 }
 
 MODULE_AUTHOR("Zou Nan hai <nanhai.zou@intel.com>");