ixp2000_reg_write(IXP2000_IRQ_ENABLE_CLR, (1 << irq));
ixp2000_reg_wrb(IXP2000_IRQ_ENABLE_CLR, (1 << irq));
static void ixp2000_irq_mask(unsigned int irq){	ixp2000_reg_write(IXP2000_IRQ_ENABLE_CLR, (1 << irq));}