DMA_CHAN_RX_WATCHDOG
writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(queue));
reg_space[DMA_CHAN_RX_WATCHDOG(default_addrs, channel) / 4] =
readl(ioaddr + DMA_CHAN_RX_WATCHDOG(dwmac4_addrs, channel));
writel(riwt, ioaddr + DMA_CHAN_RX_WATCHDOG(dwmac4_addrs, queue));