cpufreq: add __find_governor helper and clean up some error handling

Adds a __find_governor() helper function to look up a governor by name. Also restructures some error handling to conform to the "single-exit" model which is generally preferred for kernel code.

---
drivers/cpufreq/cpufreq.c | 59 ++++++++++++++++++++++++++-------------------

1 file changed, 35 insertions(+), 24 deletions(-)

diff -r 46ca283d1fe1 drivers/cpufreq/cpufreq.c
@@ -284,39 +284,52 @@ EXPORT_SYMBOL_GPL(cpufreq_notify_transit
 *                          SYSFS INTERFACE                          *
 *********************************************************************/
 
+static struct cpufreq_governor *__find_governor(const char *str_governor)
+{
+	struct cpufreq_governor *t;
+	
+	list_for_each_entry(t, &cpufreq_governor_list, governor_list)
+		if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN))
+			return t;
+
+	return NULL;
+}
+

/**
* cpufreq_parse_governor - parse a governor string
*/
static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
struct cpufreq_governor **governor)
{
+ int err = -EINVAL;
+
if (!cpufreq_driver)
- return -EINVAL;
+ goto out;
+

	if (cpufreq_driver->setpolicy) {
		if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
			*policy = CPUFREQ_POLICY_PERFORMANCE;
-			return 0;
+			err = 0;
		} else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
			*policy = CPUFREQ_POLICY_POWERSAVE;
-			return 0;
+			err = 0;
		}
-		return -EINVAL;
-	} else {
+	} else if (cpufreq_driver->target) {
		struct cpufreq_governor *t;
+
		mutex_lock(&cpufreq_governor_mutex);

- if (!cpufreq_driver || !cpufreq_driver->target)
- goto out;
- list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
- if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) {
- *governor = t;
- mutex_unlock(&cpufreq_governor_mutex);
- return 0;
- }
+
+ t = __find_governor(str_governor);
+
+ if (t != NULL) {
+ *governor = t;

+			err = 0;
		}
-out:
+
		mutex_unlock(&cpufreq_governor_mutex);
	}

- return -EINVAL;
+ out:
+ return err;
}

@@ -1273,23 +1286,21 @@ EXPORT_SYMBOL_GPL(cpufreq_governor);

int cpufreq_register_governor(struct cpufreq_governor *governor) {
- struct cpufreq_governor *t;
+ int err;

	if (!governor)
		return -EINVAL;

	mutex_lock(&cpufreq_governor_mutex);

- list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
- if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
- mutex_unlock(&cpufreq_governor_mutex);
- return -EBUSY;
- }
- }
- list_add(&governor->governor_list, &cpufreq_governor_list);
+ err = -EBUSY;
+ if (__find_governor(governor->name) == NULL) {
+ err = 0;
+ list_add(&governor->governor_list, &cpufreq_governor_list);
+ }

	mutex_unlock(&cpufreq_governor_mutex);

- return 0;
+ return err;
}
EXPORT_SYMBOL_GPL(cpufreq_register_governor);