xen_psm_bind_intr
cpu = irqptr->airq_cpu = xen_psm_bind_intr(irqno);
cpu = xen_psm_bind_intr(irq);
if ((cpu = xen_psm_bind_intr(irqno)) == IRQ_UNBOUND) {
if ((cpu = xen_psm_bind_intr(irqno)) == IRQ_UNBOUND) {
newcpu = xen_psm_bind_intr(irq);