cpufreq: Extract the handover of policy cpu to a helper function

During cpu offline, when the policy->cpu is going down, some other CPU
present in the policy->cpus mask is nominated as the new policy->cpu.
Extract this functionality from __cpufreq_remove_dev() and implement
it in a helper function. This helps in upcoming code reorganization.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index f7c58c7..0611ae4 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1129,6 +1129,38 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
                        CPUFREQ_UPDATE_POLICY_CPU, policy);
 }
 
+static int cpufreq_nominate_new_policy_cpu(struct cpufreq_policy *data,
+                                          unsigned int old_cpu)
+{
+       struct device *cpu_dev;
+       unsigned long flags;
+       int ret;
+
+       /* first sibling now owns the new sysfs dir */
+       cpu_dev = get_cpu_device(cpumask_first(data->cpus));
+       sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
+       ret = kobject_move(&data->kobj, &cpu_dev->kobj);
+       if (ret) {
+               pr_err("%s: Failed to move kobj: %d", __func__, ret);
+
+               WARN_ON(lock_policy_rwsem_write(old_cpu));
+               cpumask_set_cpu(old_cpu, data->cpus);
+
+               write_lock_irqsave(&cpufreq_driver_lock, flags);
+               per_cpu(cpufreq_cpu_data, old_cpu) = data;
+               write_unlock_irqrestore(&cpufreq_driver_lock, flags);
+
+               unlock_policy_rwsem_write(old_cpu);
+
+               ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj,
+                                       "cpufreq");
+
+               return -EINVAL;
+       }
+
+       return cpu_dev->id;
+}
+
 /**
  * __cpufreq_remove_dev - remove a CPU device
  *
@@ -1139,12 +1171,12 @@ static void update_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu)
 static int __cpufreq_remove_dev(struct device *dev,
                struct subsys_interface *sif)
 {
-       unsigned int cpu = dev->id, ret, cpus;
+       unsigned int cpu = dev->id, cpus;
+       int new_cpu;
        unsigned long flags;
        struct cpufreq_policy *data;
        struct kobject *kobj;
        struct completion *cmp;
-       struct device *cpu_dev;
 
        pr_debug("%s: unregistering CPU %u\n", __func__, cpu);
 
@@ -1179,32 +1211,15 @@ static int __cpufreq_remove_dev(struct device *dev,
        if (cpu != data->cpu) {
                sysfs_remove_link(&dev->kobj, "cpufreq");
        } else if (cpus > 1) {
-               /* first sibling now owns the new sysfs dir */
-               cpu_dev = get_cpu_device(cpumask_first(data->cpus));
-               sysfs_remove_link(&cpu_dev->kobj, "cpufreq");
-               ret = kobject_move(&data->kobj, &cpu_dev->kobj);
-               if (ret) {
-                       pr_err("%s: Failed to move kobj: %d", __func__, ret);
 
+               new_cpu = cpufreq_nominate_new_policy_cpu(data, cpu);
+               if (new_cpu >= 0) {
                        WARN_ON(lock_policy_rwsem_write(cpu));
-                       cpumask_set_cpu(cpu, data->cpus);
-
-                       write_lock_irqsave(&cpufreq_driver_lock, flags);
-                       per_cpu(cpufreq_cpu_data, cpu) = data;
-                       write_unlock_irqrestore(&cpufreq_driver_lock, flags);
-
+                       update_policy_cpu(data, new_cpu);
                        unlock_policy_rwsem_write(cpu);
-
-                       ret = sysfs_create_link(&cpu_dev->kobj, &data->kobj,
-                                       "cpufreq");
-                       return -EINVAL;
+                       pr_debug("%s: policy Kobject moved to cpu: %d "
+                                "from: %d\n",__func__, new_cpu, cpu);
                }
-
-               WARN_ON(lock_policy_rwsem_write(cpu));
-               update_policy_cpu(data, cpu_dev->id);
-               unlock_policy_rwsem_write(cpu);
-               pr_debug("%s: policy Kobject moved to cpu: %d from: %d\n",
-                               __func__, cpu_dev->id, cpu);
        }
 
        /* If cpu is last user of policy, free policy */