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

[Geert Uytterhoeven]

Hi Paul,

On Mon, Apr 8, 2024 at 7:49 PM Paul E. McKenney <paulmck@xxxxxxxxxx> 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@xxxxxxxxxx>

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.

>         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-m68korg

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