pin_2_irq
irq = pin_2_irq(i, ioapic_idx, mp_irqs[i].dstirq, 0);
return pin_2_irq(best_idx, best_ioapic, mp_irqs[best_idx].dstirq, IOAPIC_MAP_ALLOC);
pin_2_irq(idx, ioapic, pin, ioapic ? 0 : IOAPIC_MAP_ALLOC);