Merge "cpufreq: cpu-boost: Fix deadlock in wake_up of sync threads"

 * The CPUFREQ_ADJUST notifier is used to override the current policy min to

 * make sure policy min >= boost_min. The cpufreq framework then does the job

 * of enforcing the new policy.

 *

 * The sync kthread needs to run on the CPU in question to avoid deadlocks in

 * the wake up code. Achieve this by binding the thread to the respective

 * CPU. But a CPU going offline unbinds threads from that CPU. So, set it up

 * again each time the CPU comes back up. We can use CPUFREQ_START to figure

 * out a CPU is coming online instead of registering for hotplug notifiers.

 */

static int boost_adjust_notify(struct notifier_block *nb, unsigned long val,

				void *data)

	unsigned int ib_min = s->input_boost_min;

	unsigned int min;

	if (val != CPUFREQ_ADJUST)

		return NOTIFY_OK;

	switch (val) {

	case CPUFREQ_ADJUST:

		if (!b_min && !ib_min)

		return NOTIFY_OK;

			break;

		min = max(b_min, ib_min);

		pr_debug("CPU%u policy min after boost: %u kHz\n",

			 cpu, policy->min);

		break;

	case CPUFREQ_START:

		set_cpus_allowed(s->thread, *cpumask_of(cpu));

		break;

	}

	return NOTIFY_OK;

}

		INIT_DELAYED_WORK(&s->input_boost_rem, do_input_boost_rem);

		s->thread = kthread_run(boost_mig_sync_thread, (void *)cpu,

					"boost_sync/%d", cpu);

		set_cpus_allowed(s->thread, *cpumask_of(cpu));

	}

	atomic_notifier_chain_register(&migration_notifier_head,

					&boost_migration_nb);