linux-kernel - Re: [PATCH 12/24] x86: Update _static_cpu

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Date:   Thu, 25 Jan 2018 20:31:49 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     David Woodhouse <dwmw2@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        linux-kernel@...r.kernel.org, Dave Hansen <dave.hansen@...el.com>,
        Ashok Raj <ashok.raj@...el.com>,
        Tim Chen <tim.c.chen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Greg KH <gregkh@...uxfoundation.org>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Arjan Van De Ven <arjan.van.de.ven@...el.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Jun Nakajima <jun.nakajima@...el.com>,
        Asit Mallick <asit.k.mallick@...el.com>,
        Jason Baron <jbaron@...mai.com>
Subject: Re: [PATCH 12/24] x86: Update _static_cpu_has to use all named
 variables

On Tue, Jan 23, 2018 at 04:25:51PM +0100, Peter Zijlstra wrote:
> 
> Requested-by: Josh Poimboeuf <jpoimboe@...hat.com>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
> ---
>  arch/x86/include/asm/cpufeature.h |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> --- a/arch/x86/include/asm/cpufeature.h
> +++ b/arch/x86/include/asm/cpufeature.h
> @@ -153,7 +153,7 @@ static __always_inline __pure bool _stat
>  		 ".section .altinstructions,\"a\"\n"
>  		 " .long 1b - .\n"		/* src offset */
>  		 " .long 4f - .\n"		/* repl offset */
> -		 " .word %P1\n"			/* always replace */
> +		 " .word %P[always]\n"		/* always replace */
>  		 " .byte 3b - 1b\n"		/* src len */
>  		 " .byte 5f - 4f\n"		/* repl len */
>  		 " .byte 3b - 2b\n"		/* pad len */
> @@ -165,7 +165,7 @@ static __always_inline __pure bool _stat
>  		 ".section .altinstructions,\"a\"\n"
>  		 " .long 1b - .\n"		/* src offset */
>  		 " .long 0\n"			/* no replacement */
> -		 " .word %P0\n"			/* feature bit */
> +		 " .word %P[feature]\n"		/* feature bit */
>  		 " .byte 3b - 1b\n"		/* src len */
>  		 " .byte 0\n"			/* repl len */
>  		 " .byte 0\n"			/* pad len */
> @@ -176,8 +176,9 @@ static __always_inline __pure bool _stat
>  		 " jnz %l[t_yes]\n"
>  		 " jmp %l[t_no]\n"
>  		 ".previous\n"
> -		 : : "i" (bit), "i" (X86_FEATURE_ALWAYS),
> -		     [bitnum] "i" (1 << (bit & 7)),
> +		 : : [feature]  "i" (bit),
> +		     [always]   "i" (X86_FEATURE_ALWAYS),
> +		     [bitnum]   "i" (1 << (bit & 7)),
>  		     [cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
>  		 : : t_yes, t_no);
>  t_yes:

Reviewed-by: Borislav Petkov <bp@...e.de>

-- 
Regards/Gruss,
    Boris.

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