HOST_PORTS_IMPL
impl = readl(hpriv->mmio + HOST_PORTS_IMPL);
reg_val = readl(hpriv->mmio + HOST_PORTS_IMPL);
writel(reg_val, hpriv->mmio + HOST_PORTS_IMPL);
port_map = readl(mmio + HOST_PORTS_IMPL);
writel(hpriv->saved_port_map, mmio + HOST_PORTS_IMPL);
(void) readl(mmio + HOST_PORTS_IMPL); /* flush */