[CPUFREQ] [1/2] 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.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Dave Jones <davej@redhat.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ad996c772c8b7219a4d587f91fb47df4dff4e7f7..9b416372a8e426d94fe6248a36b46b56669d6a3c 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -284,39 +284,52 @@ EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
  *                          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;
 }
 
 
@@ -1265,23 +1278,21 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
 
 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;
-               }
+       err = -EBUSY;
+       if (__find_governor(governor->name) == NULL) {
+               err = 0;
+               list_add(&governor->governor_list, &cpufreq_governor_list);
        }
-       list_add(&governor->governor_list, &cpufreq_governor_list);
 
        mutex_unlock(&cpufreq_governor_mutex);
-       return 0;
+       return err;
 }
 EXPORT_SYMBOL_GPL(cpufreq_register_governor);