Re: [PATCHv9 1/5] arm64: io: Use asm-generic high level MMIO accessors

From: Catalin Marinas
Date: Wed Feb 09 2022 - 13:57:23 EST


On Mon, Jan 24, 2022 at 12:03:30PM +0530, Sai Prakash Ranjan wrote:
> Remove custom arm64 MMIO accessors read{b,w,l,q} and their relaxed
> versions in support to use asm-generic defined accessors. Also define
> one set of IO barriers (ar/bw version) used by asm-generic code to
> override the arm64 specific variants.
>
> Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Sai Prakash Ranjan <quic_saipraka@xxxxxxxxxxx>

I'm fine with this patch:

Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>

> diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
> index 7fd836bea7eb..1b436810d779 100644
> --- a/arch/arm64/include/asm/io.h
> +++ b/arch/arm64/include/asm/io.h
[...]
> +/* arm64-specific, don't use in portable drivers */
> +#define __iormb(v) __io_ar(v)
> +#define __iowmb() __io_bw()
> +#define __iomb() dma_mb()

However, I'd like to see a few subsequent patches that get rid of the
__io*mb() uses in drivers/ (there don't seem to be that many).

--
Catalin