Re: [PATCH v4 3/4] arch/*/io.h: remove ioremap_uc in some architectures

From: Michael Ellerman
Date: Thu Mar 09 2023 - 17:55:24 EST


Baoquan He <bhe@xxxxxxxxxx> writes:
> ioremap_uc() is only meaningful on old x86-32 systems with the PAT
> extension, and on ia64 with its slightly unconventional ioremap()
> behavior. So remove the ioremap_uc() definition in architecutures
> other than x86 and ia64. These architectures all have asm-generic/io.h
> included and will have the default ioremap_uc() definition which
> returns NULL.
>
> This changes the existing behaviour, while no need to worry about
> any breakage because in the only callsite of ioremap_uc(), code
> has been adjusted to eliminate the impact. Please see
> atyfb_setup_generic() of drivers/video/fbdev/aty/atyfb_base.c.
>
> If any new invocation of ioremap_uc() need be added, please consider
> using ioremap() intead or adding a ARCH specific version if necessary.
>
> Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> Cc: linux-alpha@xxxxxxxxxxxxxxx
> Cc: linux-hexagon@xxxxxxxxxxxxxxx
> Cc: linux-m68k@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-mips@xxxxxxxxxxxxxxx
> Cc: linux-parisc@xxxxxxxxxxxxxxx
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: linux-sh@xxxxxxxxxxxxxxx
> Cc: sparclinux@xxxxxxxxxxxxxxx
> ---
> Documentation/driver-api/device-io.rst | 9 +++++----
> arch/alpha/include/asm/io.h | 1 -
> arch/hexagon/include/asm/io.h | 3 ---
> arch/m68k/include/asm/kmap.h | 1 -
> arch/mips/include/asm/io.h | 1 -
> arch/parisc/include/asm/io.h | 2 --
> arch/powerpc/include/asm/io.h | 1 -

Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> (powerpc)

cheers