cpufreq: move call to __find_governor() to cpufreq_init_policy()

We call __find_governor() during the addition of the first CPU of
each policy from __cpufreq_add_dev() to find the last governor used
for this CPU before it was hot-removed.

After that we call cpufreq_parse_governor() in cpufreq_init_policy(),
either with this governor, or with the default governor. Right after
that policy->governor is set to NULL.

While that code is not functionally problematic, the structure of it
is suboptimal, because some of the code required in cpufreq_init_policy()
is being executed by its caller, __cpufreq_add_dev(). So, it would make
more sense to get all of it together in a single place to make code more
readable.

Accordingly, move the code needed for policy initialization to
cpufreq_init_policy() and initialize policy->governor to NULL at the
beginning.

In order to clean up the code a bit more, some of the #ifdefs for
CONFIG_HOTPLUG_CPU are dropped too.

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

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index df95c039a21c5c3122b33d55c518909057c8c6e4..2de2f1ddd95f74ad30e4ab06e67dafbe16f9c4e7 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -42,10 +42,8 @@ static DEFINE_RWLOCK(cpufreq_driver_lock);
 DEFINE_MUTEX(cpufreq_governor_lock);
 static LIST_HEAD(cpufreq_policy_list);
 
-#ifdef CONFIG_HOTPLUG_CPU
 /* This one keeps track of the previously set governor of a removed CPU */
 static DEFINE_PER_CPU(char[CPUFREQ_NAME_LEN], cpufreq_cpu_governor);
-#endif
 
 static inline bool has_target(void)
 {
@@ -879,18 +877,25 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
 
 static void cpufreq_init_policy(struct cpufreq_policy *policy)
 {
+       struct cpufreq_governor *gov = NULL;
        struct cpufreq_policy new_policy;
        int ret = 0;
 
        memcpy(&new_policy, policy, sizeof(*policy));
 
+       /* Update governor of new_policy to the governor used before hotplug */
+       gov = __find_governor(per_cpu(cpufreq_cpu_governor, policy->cpu));
+       if (gov)
+               pr_debug("Restoring governor %s for cpu %d\n",
+                               policy->governor->name, policy->cpu);
+       else
+               gov = CPUFREQ_DEFAULT_GOVERNOR;
+
+       new_policy.governor = gov;
+
        /* Use the default policy if its valid. */
        if (cpufreq_driver->setpolicy)
-               cpufreq_parse_governor(policy->governor->name,
-                                       &new_policy.policy, NULL);
-
-       /* assure that the starting sequence is run in cpufreq_set_policy */
-       policy->governor = NULL;
+               cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);
 
        /* set default policy */
        ret = cpufreq_set_policy(policy, &new_policy);
@@ -949,6 +954,8 @@ static struct cpufreq_policy *cpufreq_policy_restore(unsigned int cpu)
 
        read_unlock_irqrestore(&cpufreq_driver_lock, flags);
 
+       policy->governor = NULL;
+
        return policy;
 }
 
@@ -1036,7 +1043,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
        unsigned long flags;
 #ifdef CONFIG_HOTPLUG_CPU
        struct cpufreq_policy *tpolicy;
-       struct cpufreq_governor *gov;
 #endif
 
        if (cpu_is_offline(cpu))
@@ -1094,7 +1100,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
        else
                policy->cpu = cpu;
 
-       policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
        cpumask_copy(policy->cpus, cpumask_of(cpu));
 
        init_completion(&policy->kobj_unregister);
@@ -1180,15 +1185,6 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
        blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
                                     CPUFREQ_START, policy);
 
-#ifdef CONFIG_HOTPLUG_CPU
-       gov = __find_governor(per_cpu(cpufreq_cpu_governor, cpu));
-       if (gov) {
-               policy->governor = gov;
-               pr_debug("Restoring governor %s for cpu %d\n",
-                      policy->governor->name, cpu);
-       }
-#endif
-
        if (!frozen) {
                ret = cpufreq_add_dev_interface(policy, dev);
                if (ret)
@@ -1314,11 +1310,9 @@ static int __cpufreq_remove_dev_prepare(struct device *dev,
                }
        }
 
-#ifdef CONFIG_HOTPLUG_CPU
        if (!cpufreq_driver->setpolicy)
                strncpy(per_cpu(cpufreq_cpu_governor, cpu),
                        policy->governor->name, CPUFREQ_NAME_LEN);
-#endif
 
        down_read(&policy->rwsem);
        cpus = cpumask_weight(policy->cpus);
@@ -1950,9 +1944,7 @@ EXPORT_SYMBOL_GPL(cpufreq_register_governor);
 
 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
 {
-#ifdef CONFIG_HOTPLUG_CPU
        int cpu;
-#endif
 
        if (!governor)
                return;
@@ -1960,14 +1952,12 @@ void cpufreq_unregister_governor(struct cpufreq_governor *governor)
        if (cpufreq_disabled())
                return;
 
-#ifdef CONFIG_HOTPLUG_CPU
        for_each_present_cpu(cpu) {
                if (cpu_online(cpu))
                        continue;
                if (!strcmp(per_cpu(cpufreq_cpu_governor, cpu), governor->name))
                        strcpy(per_cpu(cpufreq_cpu_governor, cpu), "\0");
        }
-#endif
 
        mutex_lock(&cpufreq_governor_mutex);
        list_del(&governor->governor_list);