flush_kernel_dcache_page fixes and removal

[Linus Torvalds]

On Sun, Jul 11, 2021 at 11:09 PM Christoph Hellwig <hch at lst.de> wrote:
>
> I think we should just remove it and eat the very minor overhead in
> exec rather than confusing poor driver writers.

Ack.

I think architectures that have virtual caches might want to think
about this patch a bit more, but on the whole I can't argue against
the "it's badly documented and misused".

No sane architecture will care, since dcache will be coherent (there
are more issues on the I$ side, but that's a different issue)

              Linus