[PATCH RFC v3 01/21] ACPI: Only enumerate enabled (or functional) devices

[Russell King (Oracle)]

On Thu, Dec 14, 2023 at 07:37:10PM +0100, Rafael J. Wysocki wrote:
> On Thu, Dec 14, 2023 at 7:16 PM Rafael J. Wysocki <rafael at kernel.org> wrote:
> >
> > On Thu, Dec 14, 2023 at 7:10 PM Russell King (Oracle)
> > <linux at armlinux.org.uk> wrote:
> > > I guess we need something like:
> > >
> > >         if (device->status.present)
> > >                 return device->device_type != ACPI_BUS_TYPE_PROCESSOR ||
> > >                        device->status.enabled;
> > >         else
> > >                 return device->status.functional;
> > >
> > > so we only check device->status.enabled for processor-type devices?
> >
> > Yes, something like this.
> 
> However, that is not sufficient, because there are
> ACPI_BUS_TYPE_DEVICE devices representing processors.
> 
> I'm not sure about a clean way to do it ATM.

Ok, how about:

static bool acpi_dev_is_processor(const struct acpi_device *device)
{
	struct acpi_hardware_id *hwid;

	if (device->device_type == ACPI_BUS_TYPE_PROCESSOR)
		return true;

	if (device->device_type != ACPI_BUS_TYPE_DEVICE)
		return false;

	list_for_each_entry(hwid, &device->pnp.ids, list)
		if (!strcmp(ACPI_PROCESSOR_OBJECT_HID, hwid->id) ||
		    !strcmp(ACPI_PROCESSOR_DEVICE_HID, hwid->id))
			return true;

	return false;
}

and then:

	if (device->status.present)
		return !acpi_dev_is_processor(device) || device->status.enabled;
	else
		return device->status.functional;

?

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