linux-kernel - Re: [PATCH v2 2/2] x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB when available

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Date:   Tue, 17 Apr 2018 10:40:49 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Cc:     linux-kernel@...r.kernel.org, x86@...nel.org, tglx@...utronix.de,
        mingo@...hat.com, hpa@...or.com, rientjes@...gle.com
Subject: Re: [PATCH v2 2/2] x86/CPU/AMD: Derive CPU topology from CPUID Fn0xB
 when available

On Wed, Apr 04, 2018 at 01:45:14AM -0500, Suravee Suthikulpanit wrote:
> Derive topology information from Extended Topology Enumeration
> (CPUID Fn0x0000000B) when the information is available.
> 
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
> ---
>  arch/x86/kernel/cpu/amd.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index 2c1a9f2..cdd67d1 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -327,6 +327,7 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
>  
>  	/* get information required for multi-node processors */
>  	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
> +		int err;
>  		u32 eax, ebx, ecx, edx;
>  
>  		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
> @@ -344,6 +345,14 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
>  				c->x86_max_cores /= smp_num_siblings;
>  		}
>  
> +		/*
> +		 * In case leaf B is avaialble, use leaf B to derive

s/avaialble/available/

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--