Re: [PATCH 2/2] xen/arm: asm/atomic.h: Fix MISRA C 2012 Rule 2.5 violation

From: Julien Grall <julien@xen.org>
To: Xenia Ragiadakou <burzalodowa@gmail.com>, xen-devel@lists.xenproject.org
Cc: Stefano Stabellini <sstabellini@kernel.org>,
	Bertrand Marquis <bertrand.marquis@arm.com>,
	Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
Subject: Re: [PATCH 2/2] xen/arm: asm/atomic.h: Fix MISRA C 2012 Rule 2.5 violation
Date: Wed, 27 Jul 2022 16:46:55 +0100	[thread overview]
Message-ID: <d0e8f4b6-a66e-48c3-4f29-728cc7f5fafc@xen.org> (raw)
In-Reply-To: <20220727153254.1143503-3-burzalodowa@gmail.com>

Hi Xenia,

On 27/07/2022 16:32, Xenia Ragiadakou wrote:
> Remove unused macro atomic_xchg().
> 
> Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
> ---
>   xen/arch/arm/include/asm/atomic.h | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/xen/arch/arm/include/asm/atomic.h b/xen/arch/arm/include/asm/atomic.h
> index f5ef744b4b..a2dc125291 100644
> --- a/xen/arch/arm/include/asm/atomic.h
> +++ b/xen/arch/arm/include/asm/atomic.h
> @@ -223,8 +223,6 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
>       return __atomic_add_unless(v, a, u);
>   }
>   
> -#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
> -

While I agree this is unused today, the wrapper is quite trivial and 
part of the generic API (x86 also provides one). So I am not in favor of 
removing it just to please MISRA.

That said, if Bertrand and Stefano agrees with removing it then you 
should also remove the x86 version to avoid inconsistency.

Cheers,

-- 
Julien Grall