[PATCH 7/8] 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 | 98 ++++++++++++++++++++-------------------------
>  2 files changed, 50 insertions(+), 55 deletions(-)
>

[...]

> diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
> index a257fc0..8f9bea3 100644
> --- a/drivers/perf/arm_pmu_acpi.c
> +++ b/drivers/perf/arm_pmu_acpi.c
> @@ -35,6 +35,11 @@ struct pmu_types {
>  
>  static struct pmu_irq pmu_irqs[NR_CPUS] __initdata;
>  
> +/*
> + * Called from acpi_map_gic_cpu_interface()'s MADT parsing during boot.
> + * This routine saves off the GSI's and their trigger state for use when we are
> + * ready to build the PMU platform device.
> +*/
>  void __init arm_pmu_parse_acpi(int cpu, struct acpi_madt_generic_interrupt *gic)
>  {
>  	pmu_irqs[cpu].gsi = gic->performance_interrupt;


This hunk should be in Patch 3.

> @@ -47,7 +52,7 @@ 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 pmu_types *pmus)
> +static void __init arm_pmu_acpi_determine_cpu_types(struct pmu_types *pmus)
>  {
>  	int i, j;
>  

Please move this and the following two hunks to the previous patch where you
introduce the functions.

> @@ -74,7 +79,7 @@ void __init arm_pmu_acpi_determine_cpu_types(struct pmu_types *pmus)
>   * Registers the group of PMU interfaces which corrispond to the 'last_cpu_id'.
>   * This group utlizes '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;
> @@ -121,7 +126,7 @@ 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;
> @@ -164,63 +169,48 @@ 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;
> +	int j, last_cpu_id;
> +	struct pmu_types *pmus;
>  
> +	pr_debug("Prepare registration\n");
>  	if (acpi_disabled)
>  		return 0;
>  
> -	/* Must have irq for boot 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(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;
> -	}
> -
> -	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);
> +	pmus = kcalloc(num_possible_cpus(), sizeof(struct pmu_types),
> +		       GFP_KERNEL);
> +
> +	if (pmus) {

Instead, check for error here. That should allow you to reduce
indentation on the block below.

> +		arm_pmu_acpi_determine_cpu_types(pmus);
> +
> +		for (j = 0; pmus[j].cpu_count; j++) {
> +			pr_devel("CPU type %X, count %d\n", pmus[j].cpu_type,
> +				 pmus[j].cpu_count);
> +			res = kcalloc(pmus[j].cpu_count,
> +				      sizeof(struct resource), GFP_KERNEL);
> +
> +			/* for a given PMU type collect all the GSIs. */
> +			if (res) {
> +				count = arm_pmu_acpi_gsi_res(&pmus[j], res,
> +							     &last_cpu_id);
> +				/*
> +				 * register this set of interrupts
> +				 * with a new PMU device
> +				 */
> +				err = arm_pmu_acpi_register_pmu(count,
> +								res,
> +								last_cpu_id);
> +				kfree(res);
> +			} else
> +				pr_warn("PMU unable to allocate interrupt resource space\n");
> +		}
>  
> +		kfree(pmus);
> +	} else
> +		pr_warn("PMU: Unable to allocate pmu count structures\n");
>  	return err;
>  }
> +
>  arch_initcall(pmu_acpi_init);