[PATCH 10/11] arm64: pmu: Enable multiple PMUs in an ACPI system

[Punit Agrawal]

Jeremy Linton <jeremy.linton at arm.com> writes:

> Its possible that an ACPI system has multiple CPU types in it
> with differing PMU counters. Use the newly provided acpi_pmu routines
> to detect that case, and instantiate more than one set of counters.
>
> Signed-off-by: Jeremy Linton <jeremy.linton at arm.com>
> ---
>  drivers/perf/arm_pmu.c      |  7 +++-
>  drivers/perf/arm_pmu_acpi.c | 82 ++++++++++++++++-----------------------------
>  2 files changed, 35 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
> index 28cac3a..f94d279 100644
> --- a/drivers/perf/arm_pmu.c
> +++ b/drivers/perf/arm_pmu.c
> @@ -1044,7 +1044,12 @@ int arm_pmu_device_probe(struct platform_device *pdev,
>  		if (!ret)
>  			ret = init_fn(pmu);
>  	} else if (probe_table) {
> -		ret = probe_plat_pmu(pmu, probe_table, read_cpuid_id());
> +		if (acpi_disabled) {
> +			/* use the current cpu. */
> +			ret = probe_plat_pmu(pmu, probe_table,
> +					     read_cpuid_id());
> +		} else
> +			ret = probe_plat_pmu(pmu, probe_table, pdev->id);
>  	}
>  
>  	if (ret) {
> diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
> index 482a54d..6f5df1a 100644
> --- a/drivers/perf/arm_pmu_acpi.c
> +++ b/drivers/perf/arm_pmu_acpi.c
> @@ -50,7 +50,7 @@ void __init arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic)
>  }
>  
>  /* Count number and type of CPU cores in the system. */
> -void __init arm_pmu_acpi_determine_cpu_types(struct list_head *pmus)
> +static void __init arm_pmu_acpi_determine_cpu_types(struct list_head *pmus)
>  {
>  	int i;
>  
> @@ -84,7 +84,7 @@ void __init arm_pmu_acpi_determine_cpu_types(struct list_head *pmus)
>   * Registers the group of PMU interfaces which correspond to the 'last_cpu_id'.
>   * This group utilizes 'count' resources in the 'res'.
>   */
> -int __init arm_pmu_acpi_register_pmu(int count, struct resource *res,
> +static int __init arm_pmu_acpi_register_pmu(int count, struct resource *res,
>  					    int last_cpu_id)
>  {
>  	int i;
> @@ -130,7 +130,7 @@ int __init arm_pmu_acpi_register_pmu(int count, struct resource *res,
>   * them to the resource structure. Return the number of GSI's contained
>   * in the res structure, and the id of the last CPU/PMU we added.
>   */
> -int __init arm_pmu_acpi_gsi_res(struct pmu_types *pmus,
> +static int __init arm_pmu_acpi_gsi_res(struct pmu_types *pmus,
>  				       struct resource *res, int *last_cpu_id)
>  {
>  	int i, count;
> @@ -169,63 +169,39 @@ int __init arm_pmu_acpi_gsi_res(struct pmu_types *pmus,
>  
>  static int __init pmu_acpi_init(void)
>  {
> -	struct platform_device *pdev;
> -	struct pmu_irq *pirq = pmu_irqs;
> -	struct resource	*res, *r;
> +	struct resource	*res;
>  	int err = -ENOMEM;
> -	int i, count, irq;
> +	int count, cpu_id;
> +	struct pmu_types *pmu, *safe_temp;
> +	LIST_HEAD(pmus);
>  
>  	if (acpi_disabled)
>  		return 0;
>  
> -	/* Must have irq for boot cpu, at least */
> -	if (pirq->gsi == 0)
> -		return -EINVAL;
> -
> -	irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
> -				ACPI_ACTIVE_HIGH);
> -
> -	if (irq_is_percpu(irq))
> -		count = 1;
> -	else
> -		for (i = 1, count = 1; i < NR_CPUS; i++)
> -			if (pmu_irqs[i].gsi)
> -				++count;
> -
> -	pdev = platform_device_alloc(ARMV8_PMU_PDEV_NAME, -1);
> -	if (!pdev)
> -		goto err_free_gsi;
> -
> -	res = kcalloc(count, sizeof(*res), GFP_KERNEL);
> -	if (!res)
> -		goto err_free_device;
> -
> -	for (i = 0, r = res; i < count; i++, pirq++, r++) {
> -		if (i)
> -			irq = acpi_register_gsi(NULL, pirq->gsi, pirq->trigger,
> -						ACPI_ACTIVE_HIGH);
> -		r->start = r->end = irq;
> -		r->flags = IORESOURCE_IRQ;
> -		if (pirq->trigger == ACPI_EDGE_SENSITIVE)
> -			r->flags |= IORESOURCE_IRQ_HIGHEDGE;
> -		else
> -			r->flags |= IORESOURCE_IRQ_HIGHLEVEL;
> +	arm_pmu_acpi_determine_cpu_types(&pmus);
> +
> +	list_for_each_entry_safe(pmu, safe_temp, &pmus, list) {
> +		res = kcalloc(pmu->cpu_count,
> +			      sizeof(struct resource), GFP_KERNEL);
> +
> +		/* for a given PMU type collect all the GSIs. */
> +		if (res) {
> +			count = arm_pmu_acpi_gsi_res(pmu, res,
> +						     &cpu_id);
> +			/*
> +			 * register this set of interrupts
> +			 * with a new PMU device
> +			 */
> +			err = arm_pmu_acpi_register_pmu(count, res, cpu_id);
> +			kfree(res);
> +		} else
> +			pr_warn("PMU unable to allocate interrupt resource space\n");
> +
> +		list_del(&pmu->list);
> +		kfree(pmu);
>  	}
>  
> -	err = platform_device_add_resources(pdev, res, count);
> -	if (!err)
> -		err = platform_device_add(pdev);
> -	kfree(res);
> -	if (!err)
> -		return 0;
> -
> -err_free_device:
> -	platform_device_put(pdev);
> -
> -err_free_gsi:
> -	for (i = 0; i < count; i++)
> -		acpi_unregister_gsi(pmu_irqs[i].gsi);
> -
>  	return err;
>  }
> +
>  arch_initcall(pmu_acpi_init);

The changes to arm_acpi_pmu.c should be moved to the previous
patch. It'll help see introduction of functionality and it's use in one
patch - aiding review.