IPI_IRQ
irq_create_mapping(root_domain, IPI_IRQ);
smp_ipi_irq_setup(cpu, IPI_IRQ);
irq_set_handler(IPI_IRQ, handle_percpu_irq);
if (request_irq(IPI_IRQ, ipi_interrupt, IRQF_PERCPU, "IPI", NULL))
cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
gsc_writel(IPI_IRQ - CPU_IRQ_BASE, p->hpa);
disable_percpu_irq(IPI_IRQ);
unsigned irq = irq_create_mapping(NULL, IPI_IRQ);
writel_relaxed((*cpumask_bits(mask)) << 8 | IPI_IRQ,
ipi_irq = irq_create_mapping(root_domain, IPI_IRQ);