Re: [PATCH v2 5/5] xtensa: Emulate two-byte cmpxchg

[Max Filippov]

On Wed, Sep 16, 2026 at 1:02 PM Bradley Morgan <brads@xxxxxxxxxxxxxx> wrote:
>
> Xtensa has no two-byte atomic compare and swap, so the __cmpxchg()
> switch lets case 2 fall through to __cmpxchg_called_with_bad_pointer(),
> which is declared but never defined, so a two-byte cmpxchg() fails at
> link time. Route case 2 through the new cmpxchg_emu_u16(), which takes
> natural u16 arguments, so the unsigned long old and new narrow at the
> function boundary.
>
> Signed-off-by: Bradley Morgan <brads@xxxxxxxxxxxxxx>
> ---
>  arch/xtensa/include/asm/cmpxchg.h | 1 +
>  1 file changed, 1 insertion(+)

Reviewed-by: Max Filippov <jcmvbkbc@xxxxxxxxx>

-- 
Thanks.
-- Max