Re: [PATCH v3 cmpxchg 4/4] ARM: Emulate one-byte cmpxchg

Linus Walleij
2024-06-04T20:52:36Z

Hi Paul,

thanks for your patch! This caught my eye:

On Tue, Jun 4, 2024 at 7:04 PM Paul E. McKenney <paulmck@kernel.org> wrote:

> Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on ARM systems
> with ARCH < ARMv6K.

ARCH == ARMv6.

This ARCH < ARMv6K comes from inversion of the the a bit terse
comment for ifndef CONFIG_CPU_V6, which means "out of the
post-v6 CPUs, the following applies to those > V6".

The code in the patch, IIUC make use of cmpxchg_emu_u8()
if and only if the CPU is V6.

> -#ifndef CONFIG_CPU_V6 /* min ARCH >= ARMv6K */
> +#ifdef CONFIG_CPU_V6 /* min ARCH < ARMv6K */

This is now a set with one member so this comment should say:

/* ARCH == ARMv6 */

After this change.

Yours,
Linus Walleij