linux-kernel - RE: [PATCH] only call the c function set_bios_mode if the value CONFIG_X86

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Message-ID: <fa07b3858c254cd8947434bdd89412e2@AcuMS.aculab.com>
Date:   Sat, 19 Feb 2022 20:44:07 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     'Hans Weber' <hwe.kernel@...il.com>,
        "torvalds@....osdl.org" <torvalds@....osdl.org>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] only call the c function set_bios_mode if the value
 CONFIG_X86_64 is set.

From: Hans Weber
> Sent: 19 February 2022 20:40
> 
> Signed-off-by: Hans Weber <hwe.kernel@...il.com>
> ---
>  arch/x86/boot/main.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c
> index e3add857c2c9..e4df8ff1e228 100644
> --- a/arch/x86/boot/main.c
> +++ b/arch/x86/boot/main.c
> @@ -102,14 +102,12 @@ static void query_ist(void)
>   */
>  static void set_bios_mode(void)
>  {
> -#ifdef CONFIG_X86_64
>  	struct biosregs ireg;
> 
>  	initregs(&ireg);
>  	ireg.ax = 0xec00;
>  	ireg.bx = 2;
>  	intcall(0x15, &ireg, NULL);
> -#endif
>  }
> 
>  static void init_heap(void)
> @@ -152,7 +150,9 @@ void main(void)
>  	}
> 
>  	/* Tell the BIOS what CPU mode we intend to run in. */
> +#ifdef CONFIG_X86_64
>  	set_bios_mode();
> +#endif

That should make absolutely no difference.
The empty static function will be inlined and thus discarded.

	David

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