REG_RING_INTERRUPT_BASE
int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4;
val = ioread32(nhi->iobase + REG_RING_INTERRUPT_BASE + ring);
iowrite32(val & ~mask, nhi->iobase + REG_RING_INTERRUPT_BASE + ring);
int reg = REG_RING_INTERRUPT_BASE + index;