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Subject: Re: [PATCH] x86/resctrl: Use _ASM_BX to avoid #ifdef CONFIG_X86_64
To:     Uros Bizjak <ubizjak@gmail.com>, linux-kernel@vger.kernel.org,
        x86@kernel.org, acme@kernel.org,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     Fenghua Yu <fenghua.yu@intel.com>
References: <20190606200044.5730-1-ubizjak@gmail.com>
From:   Reinette Chatre <reinette.chatre@intel.com>
Message-ID: <14baa8db-1989-4d9b-d6fb-ada9a9f1137b@intel.com>
Date:   Mon, 10 Jun 2019 10:31:31 -0700
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Hi Uros,

On 6/6/2019 1:00 PM, Uros Bizjak wrote:
> Depending on CONFIG_X86_64 _ASM_BX expands to either rbx or ebx.
> 
> Cc: Fenghua Yu <fenghua.yu@intel.com>
> Cc: Reinette Chatre <reinette.chatre@intel.com>
> Cc: x86@kernel.org
> Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
> ---
>  arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> index 604c0e3bcc83..09408794eab2 100644
> --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> @@ -431,11 +431,7 @@ static int pseudo_lock_fn(void *_rdtgrp)
>  #else
>  	register unsigned int line_size asm("esi");
>  	register unsigned int size asm("edi");
> -#ifdef CONFIG_X86_64
> -	register void *mem_r asm("rbx");
> -#else
> -	register void *mem_r asm("ebx");
> -#endif /* CONFIG_X86_64 */
> +	register void *mem_r asm(_ASM_BX);
>  #endif /* CONFIG_KASAN */
>  
>  	/*
> 

Thank you very much for catching this. I was not aware of this macro.

Acked-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette