Commit a8c73b82 authored by Kan Liang's avatar Kan Liang Committed by Peter Zijlstra
Browse files

iommu/vt-d: Clean up cpumask and hotplug for perfmon 



The iommu PMU is system-wide scope, which is supported by the generic
perf_event subsystem now.

Set the scope for the iommu PMU and remove all the cpumask and hotplug
codes.

Signed-off-by: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20240802151643.1691631-5-kan.liang@linux.intel.com
parent 08155c7f

drivers/iommu/intel/iommu.h

+0 −2
Original line number Diff line number Diff line
@@ -687,8 +687,6 @@ struct iommu_pmu { 
	DECLARE_BITMAP(used_mask, IOMMU_PMU_IDX_MAX);

	struct perf_event	*event_list[IOMMU_PMU_IDX_MAX];

	unsigned char		irq_name[16];

	struct hlist_node	cpuhp_node;

	int			cpu;

};



#define IOMMU_IRQ_ID_OFFSET_PRQ		(DMAR_UNITS_SUPPORTED)

drivers/iommu/intel/perfmon.c

+2 −109
Original line number Diff line number Diff line
@@ -34,28 +34,9 @@ static struct attribute_group iommu_pmu_events_attr_group = { 
	.attrs = attrs_empty,

};



static cpumask_t iommu_pmu_cpu_mask;



static ssize_t

cpumask_show(struct device *dev, struct device_attribute *attr, char *buf)

{

	return cpumap_print_to_pagebuf(true, buf, &iommu_pmu_cpu_mask);

}

static DEVICE_ATTR_RO(cpumask);



static struct attribute *iommu_pmu_cpumask_attrs[] = {

	&dev_attr_cpumask.attr,

	NULL

};



static struct attribute_group iommu_pmu_cpumask_attr_group = {

	.attrs = iommu_pmu_cpumask_attrs,

};



static const struct attribute_group *iommu_pmu_attr_groups[] = {

	&iommu_pmu_format_attr_group,

	&iommu_pmu_events_attr_group,

	&iommu_pmu_cpumask_attr_group,

	NULL

};
@@ -565,6 +546,7 @@ static int __iommu_pmu_register(struct intel_iommu *iommu) 
	iommu_pmu->pmu.attr_groups	= iommu_pmu_attr_groups;

	iommu_pmu->pmu.attr_update	= iommu_pmu_attr_update;

	iommu_pmu->pmu.capabilities	= PERF_PMU_CAP_NO_EXCLUDE;

	iommu_pmu->pmu.scope		= PERF_PMU_SCOPE_SYS_WIDE;

	iommu_pmu->pmu.module		= THIS_MODULE;



	return perf_pmu_register(&iommu_pmu->pmu, iommu_pmu->pmu.name, -1);
@@ -773,89 +755,6 @@ static void iommu_pmu_unset_interrupt(struct intel_iommu *iommu) 
	iommu->perf_irq = 0;

}



static int iommu_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)

{

	struct iommu_pmu *iommu_pmu = hlist_entry_safe(node, typeof(*iommu_pmu), cpuhp_node);



	if (cpumask_empty(&iommu_pmu_cpu_mask))

		cpumask_set_cpu(cpu, &iommu_pmu_cpu_mask);



	if (cpumask_test_cpu(cpu, &iommu_pmu_cpu_mask))

		iommu_pmu->cpu = cpu;



	return 0;

}



static int iommu_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)

{

	struct iommu_pmu *iommu_pmu = hlist_entry_safe(node, typeof(*iommu_pmu), cpuhp_node);

	int target = cpumask_first(&iommu_pmu_cpu_mask);



	/*

	 * The iommu_pmu_cpu_mask has been updated when offline the CPU

	 * for the first iommu_pmu. Migrate the other iommu_pmu to the

	 * new target.

	 */

	if (target < nr_cpu_ids && target != iommu_pmu->cpu) {

		perf_pmu_migrate_context(&iommu_pmu->pmu, cpu, target);

		iommu_pmu->cpu = target;

		return 0;

	}



	if (!cpumask_test_and_clear_cpu(cpu, &iommu_pmu_cpu_mask))

		return 0;



	target = cpumask_any_but(cpu_online_mask, cpu);



	if (target < nr_cpu_ids)

		cpumask_set_cpu(target, &iommu_pmu_cpu_mask);

	else

		return 0;



	perf_pmu_migrate_context(&iommu_pmu->pmu, cpu, target);

	iommu_pmu->cpu = target;



	return 0;

}



static int nr_iommu_pmu;

static enum cpuhp_state iommu_cpuhp_slot;



static int iommu_pmu_cpuhp_setup(struct iommu_pmu *iommu_pmu)

{

	int ret;



	if (!nr_iommu_pmu) {

		ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,

					      "driver/iommu/intel/perfmon:online",

					      iommu_pmu_cpu_online,

					      iommu_pmu_cpu_offline);

		if (ret < 0)

			return ret;

		iommu_cpuhp_slot = ret;

	}



	ret = cpuhp_state_add_instance(iommu_cpuhp_slot, &iommu_pmu->cpuhp_node);

	if (ret) {

		if (!nr_iommu_pmu)

			cpuhp_remove_multi_state(iommu_cpuhp_slot);

		return ret;

	}

	nr_iommu_pmu++;



	return 0;

}



static void iommu_pmu_cpuhp_free(struct iommu_pmu *iommu_pmu)

{

	cpuhp_state_remove_instance(iommu_cpuhp_slot, &iommu_pmu->cpuhp_node);



	if (--nr_iommu_pmu)

		return;



	cpuhp_remove_multi_state(iommu_cpuhp_slot);

}



void iommu_pmu_register(struct intel_iommu *iommu)

{

	struct iommu_pmu *iommu_pmu = iommu->pmu;
@@ -866,17 +765,12 @@ void iommu_pmu_register(struct intel_iommu *iommu) 
	if (__iommu_pmu_register(iommu))

		goto err;



	if (iommu_pmu_cpuhp_setup(iommu_pmu))

		goto unregister;



	/* Set interrupt for overflow */

	if (iommu_pmu_set_interrupt(iommu))

		goto cpuhp_free;

		goto unregister;



	return;



cpuhp_free:

	iommu_pmu_cpuhp_free(iommu_pmu);

unregister:

	perf_pmu_unregister(&iommu_pmu->pmu);

err:
@@ -892,6 +786,5 @@ void iommu_pmu_unregister(struct intel_iommu *iommu) 
		return;



	iommu_pmu_unset_interrupt(iommu);

	iommu_pmu_cpuhp_free(iommu_pmu);

	perf_pmu_unregister(&iommu_pmu->pmu);

}