cpufreq: governor: Avoid passing dbs_data pointers around unnecessarily

Do not pass struct dbs_data pointers to the family of functions
implementing governor operations in cpufreq_governor.c as they can
take that pointer from policy->governor by themselves.

The cpufreq_governor_init() case is slightly more complicated, since
policy->governor may be NULL when it is invoked, but then it can reach
the pointer in question via its cdata argument just fine.

While at it, rework cpufreq_governor_dbs() to avoid a pointless
policy_governor check in the CPUFREQ_GOV_POLICY_INIT case.

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

drivers/cpufreq/cpufreq_governor.c

@@ -329,9 +329,9 @@ static void free_common_dbs_info(struct cpufreq_policy *policy,
 }
 
 static int cpufreq_governor_init(struct cpufreq_policy *policy,
-				 struct dbs_data *dbs_data,
 				 struct common_dbs_data *cdata)
 {
+	struct dbs_data *dbs_data = cdata->gdbs_data;
 	unsigned int latency;
 	int ret;
 
@@ -403,9 +403,9 @@ free_dbs_data:
 	return ret;
 }
 
-static int cpufreq_governor_exit(struct cpufreq_policy *policy,
-				 struct dbs_data *dbs_data)
+static int cpufreq_governor_exit(struct cpufreq_policy *policy)
 {
+	struct dbs_data *dbs_data = policy->governor_data;
 	struct common_dbs_data *cdata = dbs_data->cdata;
 	struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(policy->cpu);
 
@@ -432,9 +432,9 @@ static int cpufreq_governor_exit(struct cpufreq_policy *policy,
 	return 0;
 }
 
-static int cpufreq_governor_start(struct cpufreq_policy *policy,
-				  struct dbs_data *dbs_data)
+static int cpufreq_governor_start(struct cpufreq_policy *policy)
 {
+	struct dbs_data *dbs_data = policy->governor_data;
 	struct common_dbs_data *cdata = dbs_data->cdata;
 	unsigned int sampling_rate, ignore_nice, j, cpu = policy->cpu;
 	struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
@@ -499,9 +499,9 @@ static int cpufreq_governor_start(struct cpufreq_policy *policy,
 	return 0;
 }
 
-static int cpufreq_governor_stop(struct cpufreq_policy *policy,
-				 struct dbs_data *dbs_data)
+static int cpufreq_governor_stop(struct cpufreq_policy *policy)
 {
+	struct dbs_data *dbs_data = policy->governor_data;
 	struct cpu_dbs_info *cdbs = dbs_data->cdata->get_cpu_cdbs(policy->cpu);
 	struct cpu_common_dbs_info *shared = cdbs->shared;
 
@@ -515,9 +515,9 @@ static int cpufreq_governor_stop(struct cpufreq_policy *policy,
 	return 0;
 }
 
-static int cpufreq_governor_limits(struct cpufreq_policy *policy,
-				   struct dbs_data *dbs_data)
+static int cpufreq_governor_limits(struct cpufreq_policy *policy)
 {
+	struct dbs_data *dbs_data = policy->governor_data;
 	struct common_dbs_data *cdata = dbs_data->cdata;
 	unsigned int cpu = policy->cpu;
 	struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
@@ -542,45 +542,31 @@ static int cpufreq_governor_limits(struct cpufreq_policy *policy,
 int cpufreq_governor_dbs(struct cpufreq_policy *policy,
 			 struct common_dbs_data *cdata, unsigned int event)
 {
-	struct dbs_data *dbs_data;
-	int ret;
+	int ret = -EINVAL;
 
 	/* Lock governor to block concurrent initialization of governor */
 	mutex_lock(&dbs_data_mutex);
 
-	if (have_governor_per_policy())
-		dbs_data = policy->governor_data;
-	else
-		dbs_data = cdata->gdbs_data;
-
-	if (!dbs_data && (event != CPUFREQ_GOV_POLICY_INIT)) {
-		ret = -EINVAL;
-		goto unlock;
-	}
-
-	switch (event) {
-	case CPUFREQ_GOV_POLICY_INIT:
-		ret = cpufreq_governor_init(policy, dbs_data, cdata);
-		break;
-	case CPUFREQ_GOV_POLICY_EXIT:
-		ret = cpufreq_governor_exit(policy, dbs_data);
-		break;
-	case CPUFREQ_GOV_START:
-		ret = cpufreq_governor_start(policy, dbs_data);
-		break;
-	case CPUFREQ_GOV_STOP:
-		ret = cpufreq_governor_stop(policy, dbs_data);
-		break;
-	case CPUFREQ_GOV_LIMITS:
-		ret = cpufreq_governor_limits(policy, dbs_data);
-		break;
-	default:
-		ret = -EINVAL;
+	if (event == CPUFREQ_GOV_POLICY_INIT) {
+		ret = cpufreq_governor_init(policy, cdata);
+	} else if (policy->governor_data) {
+		switch (event) {
+		case CPUFREQ_GOV_POLICY_EXIT:
+			ret = cpufreq_governor_exit(policy);
+			break;
+		case CPUFREQ_GOV_START:
+			ret = cpufreq_governor_start(policy);
+			break;
+		case CPUFREQ_GOV_STOP:
+			ret = cpufreq_governor_stop(policy);
+			break;
+		case CPUFREQ_GOV_LIMITS:
+			ret = cpufreq_governor_limits(policy);
+			break;
+		}
 	}
 
-unlock:
 	mutex_unlock(&dbs_data_mutex);
-
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cpufreq_governor_dbs);