Re: [PATCH cmpxchg 13/14] xtensa: Emulate one-byte cmpxchg

Paul E. McKenney
2024-04-18T23:21:50Z

On Thu, Apr 18, 2024 at 10:06:21AM +0200, Geert Uytterhoeven wrote:
> Hi Paul,
>
> On Mon, Apr 8, 2024 at 7:49 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> > Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on xtensa.
> >
> > [ paulmck: Apply kernel test robot feedback. ]
> > [ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]
> >
> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
>
> Thanks for your patch!
>
> > --- a/arch/xtensa/include/asm/cmpxchg.h
> > +++ b/arch/xtensa/include/asm/cmpxchg.h
> > @@ -74,6 +75,7 @@ static __inline__ unsigned long
> > __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
> > {
> > switch (size) {
> > + case 1: return cmpxchg_emu_u8((volatile u8 *)ptr, old, new);
>
> The cast is not needed.

In both cases, kernel test robot yelled at me when it was not present.

Happy to resubmit without it, though, if that is a yell that I should
have ignored.

Thanx, Paul

> > case 4: return __cmpxchg_u32(ptr, old, new);
> > default: __cmpxchg_called_with_bad_pointer();
> > return old;
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds