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References: <20230508140206.283708-1-kan.liang@linux.intel.com>
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From:   Stephane Eranian <eranian@google.com>
Date:   Mon, 8 May 2023 09:16:20 -0700
Message-ID: <CABPqkBSczJqEbA8M0HCdeqjddgDqpxapJYVYNuAS+EifJ+v+Dg@mail.gmail.com>
Subject: Re: [PATCH] perf/x86/uncore: Correct the number of CHAs on SPR
To:     kan.liang@linux.intel.com
Cc:     peterz@infradead.org, mingo@redhat.com,
        linux-kernel@vger.kernel.org, ak@linux.intel.com,
        stable@vger.kernel.org
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On Mon, May 8, 2023 at 7:05=E2=80=AFAM <kan.liang@linux.intel.com> wrote:
>
> From: Kan Liang <kan.liang@linux.intel.com>
>
> The number of CHAs from the discovery table on some SPR variants is
> incorrect, because of a firmware issue. An accurate number can be read
> from the MSR UNC_CBO_CONFIG.
>
> Fixes: 949b11381f81 ("perf/x86/intel/uncore: Add Sapphire Rapids server C=
HA support")
> Reported-by: Stephane Eranian <eranian@google.com>
> Signed-off-by: Kan Liang <kan.liang@linux.intel.com>

Tested-by: Stephane Eranian <eranian@google.com>

>
> Cc: stable@vger.kernel.org
> ---
>  arch/x86/events/intel/uncore_snbep.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel=
/uncore_snbep.c
> index 7d1199554fe3..54abd93828bf 100644
> --- a/arch/x86/events/intel/uncore_snbep.c
> +++ b/arch/x86/events/intel/uncore_snbep.c
> @@ -6138,6 +6138,7 @@ static struct intel_uncore_type spr_uncore_mdf =3D =
{
>  };
>
>  #define UNCORE_SPR_NUM_UNCORE_TYPES            12
> +#define UNCORE_SPR_CHA                         0
>  #define UNCORE_SPR_IIO                         1
>  #define UNCORE_SPR_IMC                         6
>  #define UNCORE_SPR_UPI                         8
> @@ -6448,12 +6449,22 @@ static int uncore_type_max_boxes(struct intel_unc=
ore_type **types,
>         return max + 1;
>  }
>
> +#define SPR_MSR_UNC_CBO_CONFIG         0x2FFE
> +
>  void spr_uncore_cpu_init(void)
>  {
> +       struct intel_uncore_type *type;
> +       u64 num_cbo;
> +
>         uncore_msr_uncores =3D uncore_get_uncores(UNCORE_ACCESS_MSR,
>                                                 UNCORE_SPR_MSR_EXTRA_UNCO=
RES,
>                                                 spr_msr_uncores);
>
> +       type =3D uncore_find_type_by_id(uncore_msr_uncores, UNCORE_SPR_CH=
A);
> +       if (type) {
> +               rdmsrl(SPR_MSR_UNC_CBO_CONFIG, num_cbo);
> +               type->num_boxes =3D num_cbo;
> +       }
>         spr_uncore_iio_free_running.num_boxes =3D uncore_type_max_boxes(u=
ncore_msr_uncores, UNCORE_SPR_IIO);
>  }
>
> --
> 2.35.1
>