Re: [PATCH v1 01/29] xen/asm-generic: introduce stub header spinlock.h

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Thu, 2023-09-14 at 17:35 +0200, Jan Beulich wrote:
> On 14.09.2023 16:56, Oleksii Kurochko wrote:
> > The patch introduces stub header needed for full Xen build.
> > 
> > Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> 
> Hmm, looking here I think I need to take back what I said in reply
> to the cover letter, taking this as an example.
> 
> > --- /dev/null
> > +++ b/xen/include/asm-generic/spinlock.h
> > @@ -0,0 +1,23 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ASM_GENERIC_SPINLOCK_H__
> > +#define __ASM_GENERIC_SPINLOCK_H__
> > +
> > +#define arch_lock_acquire_barrier() smp_mb()
> > +#define arch_lock_release_barrier() smp_mb()
> > +
> > +#define arch_lock_relax() cpu_relax()
> > +#define arch_lock_signal() do { \
> > +} while(0)
> 
> Slightly easier (and without style violation) as ((void)0)?
Thanks. It is much easier.

> 
> > +#define arch_lock_signal_wmb() arch_lock_signal()
> 
> How's the WMB aspect represented in here? I think you need the x86
> variant as the generic fallback.

Agree. I'll take x86 version in the next patch series.

~ Oleksii