cpufreq: Fix get_cpu_device() failed in add_cpu_dev_symlink()

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4HYY4?from=project-issue
CVE: NA

-------------------------------------------------

When I hot added a CPU, I found 'cpufreq' directory is not created below
/sys/devices/system/cpu/cpuX/. It is because get_cpu_device() failed in
add_cpu_dev_symlink().

cpufreq_add_dev() is the .add_dev callback of a CPU subsys interface. It
will be called when the CPU device registered into the system. The stack
is as follows.
  register_cpu()
  ->device_register()
   ->device_add()
    ->bus_probe_device()
     ->cpufreq_add_dev()

But only after the CPU device has been registered, we can get the CPU
device by get_cpu_device(), otherwise it will return NULL. Since we
already have the CPU device in cpufreq_add_dev(), pass it to
add_cpu_dev_symlink().
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NKeqian Zhu <zhukeqian1@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/cpufreq/cpufreq.c

@@ -965,10 +965,9 @@ static struct kobj_type ktype_cpufreq = {
 	.release	= cpufreq_sysfs_release,
 };
 
-static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu)
+static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu,
+				struct device *dev)
 {
-	struct device *dev = get_cpu_device(cpu);
-
 	if (!dev)
 		return;
 
@@ -1241,7 +1240,7 @@ static int cpufreq_online(unsigned int cpu)
 
 		for_each_cpu(j, policy->related_cpus) {
 			per_cpu(cpufreq_cpu_data, j) = policy;
-			add_cpu_dev_symlink(policy, j);
+			add_cpu_dev_symlink(policy, j, get_cpu_device(j));
 		}
 	} else {
 		policy->min = policy->user_policy.min;
@@ -1366,7 +1365,7 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
 	/* Create sysfs link on CPU registration */
 	policy = per_cpu(cpufreq_cpu_data, cpu);
 	if (policy)
-		add_cpu_dev_symlink(policy, cpu);
+		add_cpu_dev_symlink(policy, cpu, dev);
 
 	return 0;
 }