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Commit 0b275352 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

cpufreq: Separate CPU device registration from CPU online 



To separate the CPU online interface from the CPU device
registration, split cpufreq_online() out of cpufreq_add_dev()
and make cpufreq_cpu_callback() call the former, while
cpufreq_add_dev() itself will only be used as the CPU device
addition subsystem interface callback.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Suggested-by: default avatarRussell King <linux@arm.linux.org.uk>
Acked-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent 22794280

drivers/cpufreq/cpufreq.c

+47 −43
Original line number Diff line number Diff line
@@ -1191,36 +1191,15 @@ static void cpufreq_policy_free(struct cpufreq_policy *policy, bool notify) 
	kfree(policy);

}



/**

 * cpufreq_add_dev - add a CPU device

 *

 * Adds the cpufreq interface for a CPU device.

 *

 * The Oracle says: try running cpufreq registration/unregistration concurrently

 * with with cpu hotplugging and all hell will break loose. Tried to clean this

 * mess up, but more thorough testing is needed. - Mathieu

 */

static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)

static int cpufreq_online(unsigned int cpu)

{

	unsigned int j, cpu = dev->id;

	int ret;

	struct cpufreq_policy *policy;

	unsigned long flags;

	bool recover_policy;

	unsigned long flags;

	unsigned int j;

	int ret;



	pr_debug("adding CPU %u\n", cpu);



	if (cpu_is_offline(cpu)) {

		/*

		 * Only possible if we are here from the subsys_interface add

		 * callback.  A hotplug notifier will follow and we will handle

		 * it as CPU online then.  For now, just create the sysfs link,

		 * unless there is no policy or the link is already present.

		 */

		policy = per_cpu(cpufreq_cpu_data, cpu);

		return policy && !cpumask_test_and_set_cpu(cpu, policy->real_cpus)

			? add_cpu_dev_symlink(policy, cpu) : 0;

	}

	pr_debug("%s: bringing CPU%u online\n", __func__, cpu);



	/* Check if this CPU already has a policy to manage it */

	policy = per_cpu(cpufreq_cpu_data, cpu);
@@ -1377,6 +1356,35 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) 
	return ret;

}



/**

 * cpufreq_add_dev - the cpufreq interface for a CPU device.

 * @dev: CPU device.

 * @sif: Subsystem interface structure pointer (not used)

 */

static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)

{

	unsigned cpu = dev->id;

	int ret;



	dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu);



	if (cpu_online(cpu)) {

		ret = cpufreq_online(cpu);

	} else {

		/*

		 * A hotplug notifier will follow and we will handle it as CPU

		 * online then.  For now, just create the sysfs link, unless

		 * there is no policy or the link is already present.

		 */

		struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu);



		ret = policy && !cpumask_test_and_set_cpu(cpu, policy->real_cpus)

			? add_cpu_dev_symlink(policy, cpu) : 0;

	}



	return ret;

}



static void cpufreq_offline_prepare(unsigned int cpu)

{

	struct cpufreq_policy *policy;
@@ -2340,13 +2348,10 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb, 
					unsigned long action, void *hcpu)

{

	unsigned int cpu = (unsigned long)hcpu;

	struct device *dev;



	dev = get_cpu_device(cpu);

	if (dev) {

	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_ONLINE:

			cpufreq_add_dev(dev, NULL);

		cpufreq_online(cpu);

		break;



	case CPU_DOWN_PREPARE:
@@ -2358,10 +2363,9 @@ static int cpufreq_cpu_callback(struct notifier_block *nfb, 
		break;



	case CPU_DOWN_FAILED:

			cpufreq_add_dev(dev, NULL);

		cpufreq_online(cpu);

		break;

	}

	}

	return NOTIFY_OK;

}