__io_raw
#define writeb_relaxed(v, c) ({ __io_rbw(); writeb_cpu((v), (c)); __io_raw(); })
#define writew_relaxed(v, c) ({ __io_rbw(); writew_cpu((v), (c)); __io_raw(); })
#define writel_relaxed(v, c) ({ __io_rbw(); writel_cpu((v), (c)); __io_raw(); })
#define writeq_relaxed(v, c) ({ __io_rbw(); writeq_cpu((v), (c)); __io_raw(); })