int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base);
int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base);
+int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base);
void acpi_irq_stats_init(void);
extern u32 acpi_irq_handled;
extern u32 acpi_irq_not_handled;