[PATCH v3 21/29] arm_mpam: Probe and reset the rest of the features
Ben Horgan
ben.horgan at arm.com
Mon Oct 20 10:16:58 PDT 2025
Hi James,
On 10/17/25 19:56, James Morse wrote:
> MPAM supports more features than are going to be exposed to resctrl.
> For partid other than 0, the reset values of these controls isn't
> known.
>
> Discover the rest of the features so they can be reset to avoid any
> side effects when resctrl is in use.
>
> PARTID narrowing allows MSC/RIS to support less configuration space than
> is usable. If this feature is found on a class of device we are likely
> to use, then reduce the partid_max to make it usable. This allows us
> to map a PARTID to itself.
>
> CC: Rohit Mathew <Rohit.Mathew at arm.com>
> CC: Zeng Heng <zengheng4 at huawei.com>
> CC: Dave Martin <Dave.Martin at arm.com>
> Signed-off-by: James Morse <james.morse at arm.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron at huawei.com>
> Tested-by: Fenghua Yu <fenghuay at nvidia.com>
> ---
> Changes since v2:
> * Moved some enum definitions in here.
> * Whitespace.
>
[...]
> diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
> index 2f2a7369107b..00edee9ebc6c 100644
> --- a/drivers/resctrl/mpam_internal.h
> +++ b/drivers/resctrl/mpam_internal.h
> @@ -139,16 +139,30 @@ static inline void mpam_mon_sel_lock_init(struct mpam_msc *msc)
>
> /* Bits for mpam features bitmaps */
> enum mpam_device_features {
> - mpam_feat_cpor_part = 0,
Any reason this one doesn't stay first?
> + mpam_feat_cmax_softlim,
> + mpam_feat_cmax_cmax,
> + mpam_feat_cmax_cmin,
> + mpam_feat_cmax_cassoc,
> + mpam_feat_cpor_part,
> mpam_feat_mbw_part,
> mpam_feat_mbw_min,
> mpam_feat_mbw_max,
> + mpam_feat_mbw_prop,
> + mpam_feat_intpri_part,
> + mpam_feat_intpri_part_0_low,
> + mpam_feat_dspri_part,
> + mpam_feat_dspri_part_0_low,
> mpam_feat_msmon,
> mpam_feat_msmon_csu,
> + mpam_feat_msmon_csu_capture,
> + mpam_feat_msmon_csu_xcl,
> mpam_feat_msmon_csu_hw_nrdy,
> mpam_feat_msmon_mbwu,
> + mpam_feat_msmon_mbwu_capture,
> + mpam_feat_msmon_mbwu_rwbw,
> mpam_feat_msmon_mbwu_hw_nrdy,
> - MPAM_FEATURE_LAST
> + mpam_feat_partid_nrw,
> + MPAM_FEATURE_LAST,
nit: drop the trailing , from MPAM_FEATURE_LAST. It confuses the diff.
> };
>
--
Thanks,
Ben
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