[PATCH v12 6/7] arm64: pmu: Detect and enable multiple PMUs in an ACPI system

Lorenzo Pieralisi lorenzo.pieralisi at arm.com
Mon Jan 16 10:28:38 PST 2017


On Tue, Jan 10, 2017 at 11:17:51AM -0600, Jeremy Linton wrote:

[...]

> +static int __init pmu_acpi_init(void)
> +{
> +	struct pmu_types *pmu, *safe_temp;
> +	bool unused_madt_entries;
> +	LIST_HEAD(pmus);
> +
> +	if (acpi_disabled)
> +		return 0;
> +
> +	unused_madt_entries = arm_pmu_acpi_determine_cpu_types(&pmus);

IIUC (and that's an if) unused_madt_entries is a "buffer" that you add
to all platform devices you manage to create through midr matching to
make sure there are enough resource entries when/if a cpu of the
respective type is onlined.

If that's the case unused_madt_entries can't be a bool.

Second question I have is what happens if cpus that aren't online
have an midr that differs from all the entries parsed at init time
(ie those you created a platform device for), that's certainly
a pesky corner case though.

Thanks,
Lorenzo

> +
> +	list_for_each_entry_safe(pmu, safe_temp, &pmus, list) {
> +		pmu->cpu_count += unused_madt_entries;
> +		pmu_acpi_register(pmu);
> +
> +		list_del(&pmu->list);
> +		kfree(pmu);
> +	}
> +
> +	return 0;
> +}
> +
> +arch_initcall(pmu_acpi_init);
> -- 
> 2.5.5
> 
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