Re: [PATCH 01/13] compiler.h: Split {READ,WRITE}_ONCE definitions out into rwonce.h

[Arnd Bergmann]

On Fri, Nov 8, 2019 at 6:01 PM Will Deacon <will@xxxxxxxxxx> wrote:
>
> In preparation for allowing architectures to define their own
> implementation of the 'READ_ONCE()' macro, move the generic
> '{READ,WRITE}_ONCE()' definitions out of the unwieldy 'linux/compiler.h'
> and into a new 'rwonce.h' header under 'asm-generic'.

Adding Christian BorntrÃger to Cc, he originally added the
READ_ONCE()/WRITE_ONCE()
code.

I wonder if it would be appropriate now to revert back to a much simpler version
of these helpers for any modern compiler. As I understand, only gcc-4.6 and
gcc4.7 actually need the song-and-dance version with the union and switch/case,
while for others, we can might be able back to a macro doing a volatile access.

     Arnd