acpi-processor.txt

#define ACPI_PROCESSOR_OBJECT_HID	"LNXCPU"
#define ACPI_PROCESSOR_DEVICE_HID	"ACPI0007"

static const struct acpi_device_id processor_device_ids[] = {

	{ ACPI_PROCESSOR_OBJECT_HID, },
	{ ACPI_PROCESSOR_DEVICE_HID, },

	{ }
};

static struct acpi_scan_handler processor_handler = {
	.ids = processor_device_ids,
	.attach = acpi_processor_add,
#ifdef CONFIG_ACPI_HOTPLUG_CPU
	.detach = acpi_processor_remove,
#endif
	.hotplug = {
		.enabled = true,
	},
};

acpi_processor_init:
	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");

acpi_processor_add:
	acpi_processor_get_info:
		if (invalid_logical_cpuid(pr->id) || !cpu_present(pr->id)) {
		   int ret = acpi_processor_hotadd_init(pr);
		   if (ret)
			return ret;
		}

		acpi_processor_hotadd_init:
				status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
				arch_register_cpu()
		


ACPI scan

acpi_scan_add_handler_with_hotplug:
	acpi_scan_add_handler:
		list_add_tail(&handler->list_node, &acpi_scan_handlers_list);

acpi_scan_match_handler:
	list_for_each_entry(handler, &acpi_scan_handlers_list, list_node)
		if (acpi_scan_handler_matching(handler, idstr, matchid))
			return handler;


acpi_bus_init:
	acpi_install_notify_handler(ACPI_ROOT_OBJECT, ACPI_SYSTEM_NOTIFY,
				&acpi_bus_notify, NULL);
		acpi_bus_notify:
			if (hotplug_event && ACPI_SUCCESS(acpi_hotplug_schedule(adev, type)))
			   return;

			   acpi_hotplug_schedule:
					INIT_WORK(&hpw->work, acpi_hotplug_work_fn);
					queue_work(kacpi_hotplug_wq, &hpw->work)


					acpi_hotplug_work_fn:
						acpi_device_hotplug:
							acpi_generic_hotplug_event:
								acpi_scan_bus_check
								acpi_scan_device_check