Re: [tip:x86/core 1/1] arch/x86/um/../lib/csum-partial_64.c:98:12: error: implicit declaration of function 'load_unaligned_zeropad'

[Eric Dumazet]

On Wed, Nov 17, 2021 at 10:46 AM kernel test robot <lkp@xxxxxxxxx> wrote:
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/core
> head:   d31c3c683ee668ba5d87c0730610442fd672525f
> commit: d31c3c683ee668ba5d87c0730610442fd672525f [1/1] x86/csum: Rewrite/optimize csum_partial()
> config: um-x86_64_defconfig (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
> reproduce (this is a W=1 build):
>         # https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=d31c3c683ee668ba5d87c0730610442fd672525f
>         git remote add tip https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
>         git fetch --no-tags tip x86/core
>         git checkout d31c3c683ee668ba5d87c0730610442fd672525f
>         # save the attached .config to linux build tree
>         make W=1 ARCH=um SUBARCH=x86_64
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All errors (new ones prefixed by >>):
>
>    arch/x86/um/../lib/csum-partial_64.c: In function 'csum_partial':
> >> arch/x86/um/../lib/csum-partial_64.c:98:12: error: implicit declaration of function 'load_unaligned_zeropad' [-Werror=implicit-function-declaration]
>       98 |   trail = (load_unaligned_zeropad(buff) << shift) >> shift;
>          |            ^~~~~~~~~~~~~~~~~~~~~~
>    cc1: some warnings being treated as errors
>
>

Hmmm... it seems we need to guard this with CONFIG_DCACHE_WORD_ACCESS ?