Re: [PATCH] x86/AMD: Fix Socket ID for LLC topology for AMD Fam17h systems

From: Thomas Gleixner
Date: Fri Sep 02 2016 - 04:44:03 EST


On Wed, 31 Aug 2016, Yazen Ghannam wrote:

> The Socket ID is ApicId[bits] on Fam17h systems.
>
> Change substraction to logical AND when extracting socket_id
> from c->apicid.

So Fam17h will only ever have 2 sockets, right?

Thanks,

tglx

> Signed-off-by: Yazen Ghannam <Yazen.Ghannam@xxxxxxx>
> ---
> arch/x86/kernel/cpu/amd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index f5c69d8..479555f 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -365,7 +365,7 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c)
> if (c->x86 != 0x17 || !cpuid_edx(0x80000006))
> return;
>
> - socket_id = (c->apicid >> bits) - 1;
> + socket_id = (c->apicid >> bits) & 1;
> core_complex_id = (c->apicid & ((1 << bits) - 1)) >> 3;
>
> per_cpu(cpu_llc_id, cpu) = (socket_id << 3) | core_complex_id;
> --
> 1.9.1
>
>