Commit dcabe10d authored by Will Deacon's avatar Will Deacon
Browse files

Merge branch 'for-next/topology' into for-next/core 

Cleanup to the AMU support code and initialisation rework to support
cpufreq drivers built as modules.

* for-next/topology:
  arm64: topology: Make AMUs work with modular cpufreq drivers
  arm64: topology: Reorder init_amu_fie() a bit
  arm64: topology: Avoid the have_policy check
parents d23fa87c a5f1b187

arch/arm64/kernel/topology.c

+56 −59
Original line number Diff line number Diff line
@@ -199,76 +199,38 @@ static int freq_inv_set_max_ratio(int cpu, u64 max_rate, u64 ref_rate) 
	return 0;

}



static inline bool

enable_policy_freq_counters(int cpu, cpumask_var_t valid_cpus)

{

	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);



	if (!policy) {

		pr_debug("CPU%d: No cpufreq policy found.\n", cpu);

		return false;

	}



	if (cpumask_subset(policy->related_cpus, valid_cpus))

		cpumask_or(amu_fie_cpus, policy->related_cpus,

			   amu_fie_cpus);



	cpufreq_cpu_put(policy);



	return true;

}



static DEFINE_STATIC_KEY_FALSE(amu_fie_key);

#define amu_freq_invariant() static_branch_unlikely(&amu_fie_key)



static int __init init_amu_fie(void)

static void amu_fie_setup(const struct cpumask *cpus)

{

	bool invariance_status = topology_scale_freq_invariant();

	cpumask_var_t valid_cpus;

	bool have_policy = false;

	int ret = 0;

	bool invariant;

	int cpu;



	if (!zalloc_cpumask_var(&valid_cpus, GFP_KERNEL))

		return -ENOMEM;



	if (!zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL)) {

		ret = -ENOMEM;

		goto free_valid_mask;

	}

	/* We are already set since the last insmod of cpufreq driver */

	if (unlikely(cpumask_subset(cpus, amu_fie_cpus)))

		return;



	for_each_present_cpu(cpu) {

	for_each_cpu(cpu, cpus) {

		if (!freq_counters_valid(cpu) ||

		    freq_inv_set_max_ratio(cpu,

					   cpufreq_get_hw_max_freq(cpu) * 1000,

					   arch_timer_get_rate()))

			continue;



		cpumask_set_cpu(cpu, valid_cpus);

		have_policy |= enable_policy_freq_counters(cpu, valid_cpus);

			return;

	}



	/*

	 * If we are not restricted by cpufreq policies, we only enable

	 * the use of the AMU feature for FIE if all CPUs support AMU.

	 * Otherwise, enable_policy_freq_counters has already enabled

	 * policy cpus.

	 */

	if (!have_policy && cpumask_equal(valid_cpus, cpu_present_mask))

		cpumask_or(amu_fie_cpus, amu_fie_cpus, valid_cpus);

	cpumask_or(amu_fie_cpus, amu_fie_cpus, cpus);



	invariant = topology_scale_freq_invariant();



	/* We aren't fully invariant yet */

	if (!invariant && !cpumask_equal(amu_fie_cpus, cpu_present_mask))

		return;



	if (!cpumask_empty(amu_fie_cpus)) {

		pr_info("CPUs[%*pbl]: counters will be used for FIE.",

			cpumask_pr_args(amu_fie_cpus));

	static_branch_enable(&amu_fie_key);

	}



	/*

	 * If the system is not fully invariant after AMU init, disable

	 * partial use of counters for frequency invariance.

	 */

	if (!topology_scale_freq_invariant())

		static_branch_disable(&amu_fie_key);

	pr_debug("CPUs[%*pbl]: counters will be used for FIE.",

		 cpumask_pr_args(cpus));



	/*

	 * Task scheduler behavior depends on frequency invariance support,
@@ -276,15 +238,50 @@ static int __init init_amu_fie(void) 
	 * a result of counter initialisation and use, retrigger the build of

	 * scheduling domains to ensure the information is propagated properly.

	 */

	if (invariance_status != topology_scale_freq_invariant())

	if (!invariant)

		rebuild_sched_domains_energy();

}



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

				 void *data)

{

	struct cpufreq_policy *policy = data;



	if (val == CPUFREQ_CREATE_POLICY)

		amu_fie_setup(policy->related_cpus);



	/*

	 * We don't need to handle CPUFREQ_REMOVE_POLICY event as the AMU

	 * counters don't have any dependency on cpufreq driver once we have

	 * initialized AMU support and enabled invariance. The AMU counters will

	 * keep on working just fine in the absence of the cpufreq driver, and

	 * for the CPUs for which there are no counters available, the last set

	 * value of freq_scale will remain valid as that is the frequency those

	 * CPUs are running at.

	 */



	return 0;

}



static struct notifier_block init_amu_fie_notifier = {

	.notifier_call = init_amu_fie_callback,

};



static int __init init_amu_fie(void)

{

	int ret;



	if (!zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL))

		return -ENOMEM;



free_valid_mask:

	free_cpumask_var(valid_cpus);

	ret = cpufreq_register_notifier(&init_amu_fie_notifier,

					CPUFREQ_POLICY_NOTIFIER);

	if (ret)

		free_cpumask_var(amu_fie_cpus);



	return ret;

}

late_initcall_sync(init_amu_fie);

core_initcall(init_amu_fie);



bool arch_freq_counters_available(const struct cpumask *cpus)

{