Re: [PATCH] perf/x86/uncore: Correct the number of CHAs on SPR

Stephane Eranian
2023-05-08T16:16:40Z

On Mon, May 8, 2023 at 7:05 AM <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 CHA 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 = {
> };
>
> #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_uncore_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 = uncore_get_uncores(UNCORE_ACCESS_MSR,
> UNCORE_SPR_MSR_EXTRA_UNCORES,
> spr_msr_uncores);
>
> + type = uncore_find_type_by_id(uncore_msr_uncores, UNCORE_SPR_CHA);
> + if (type) {
> + rdmsrl(SPR_MSR_UNC_CBO_CONFIG, num_cbo);
> + type->num_boxes = num_cbo;
> + }
> spr_uncore_iio_free_running.num_boxes = uncore_type_max_boxes(uncore_msr_uncores, UNCORE_SPR_IIO);
> }
>
> --
> 2.35.1
>