Message-ID: <fa7ed4fd-c1d7-405e-bdbc-443b8eea4b89@nvidia.com>
Date: Fri, 17 Oct 2025 16:03:36 -0700
From: Fenghua Yu <fenghuay@...dia.com>
To: James Morse <james.morse@....com>, linux-kernel@...r.kernel.org,
 linux-arm-kernel@...ts.infradead.org, linux-acpi@...r.kernel.org
Cc: D Scott Phillips OS <scott@...amperecomputing.com>,
 carl@...amperecomputing.com, lcherian@...vell.com,
 bobo.shaobowang@...wei.com, tan.shaopeng@...itsu.com,
 baolin.wang@...ux.alibaba.com, Jamie Iles <quic_jiles@...cinc.com>,
 Xin Hao <xhao@...ux.alibaba.com>, peternewman@...gle.com,
 dfustini@...libre.com, amitsinght@...vell.com,
 David Hildenbrand <david@...hat.com>, Dave Martin <dave.martin@....com>,
 Koba Ko <kobak@...dia.com>, Shanker Donthineni <sdonthineni@...dia.com>,
 baisheng.gao@...soc.com, Jonathan Cameron <jonathan.cameron@...wei.com>,
 Rob Herring <robh@...nel.org>, Rohit Mathew <rohit.mathew@....com>,
 Rafael Wysocki <rafael@...nel.org>, Len Brown <lenb@...nel.org>,
 Lorenzo Pieralisi <lpieralisi@...nel.org>, Hanjun Guo
 <guohanjun@...wei.com>, Sudeep Holla <sudeep.holla@....com>,
 Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
 Danilo Krummrich <dakr@...nel.org>, Jeremy Linton <jeremy.linton@....com>,
 Gavin Shan <gshan@...hat.com>, Ben Horgan <ben.horgan@....com>
Subject: Re: [PATCH v3 09/29] arm_mpam: Add MPAM MSC register layout
 definitions

Hi, James,

On 10/17/25 11:56, James Morse wrote:
> Memory Partitioning and Monitoring (MPAM) has memory mapped devices
> (MSCs) with an identity/configuration page.
>
> Add the definitions for these registers as offset within the page(s).
>
> Link: https://developer.arm.com/documentation/ihi0099/latest/
> Signed-off-by: James Morse <james.morse@....com>
> Reviewed-by: Ben Horgan <ben.horgan@....com>
> Reviewed-by: Fenghua Yu <fenghuay@...dia.com>
> Tested-by: Fenghua Yu <fenghuay@...dia.com>
> ---
> Changes since v2:
>   * Removed a few colons.
>   * fixed a typo.
>   * Moved some definitions around.
>
> Changes since v1:
>   * Whitespace.
>   * Added constants for CASSOC and XCL.
>   * Merged FLT/CTL defines.
>   * Fixed MSMON_CFG_CSU_CTL_TYPE_CSU definition.
>
> Changes since RFC:
>   * Renamed MSMON_CFG_MBWU_CTL_TYPE_CSU as MSMON_CFG_CSU_CTL_TYPE_CSU
>   * Whitepsace churn.
>   * Cite a more recent document.
>   * Removed some stale feature, fixed some names etc.
> ---
>   drivers/resctrl/mpam_internal.h | 268 ++++++++++++++++++++++++++++++++
>   1 file changed, 268 insertions(+)
>
> diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h
> index 1a5d96660382..1ef3e8e1d056 100644
> --- a/drivers/resctrl/mpam_internal.h
> +++ b/drivers/resctrl/mpam_internal.h
> @@ -142,4 +142,272 @@ extern struct list_head mpam_classes;
>   int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level,
>   				   cpumask_t *affinity);
>   
> +/*
> + * MPAM MSCs have the following register layout. See:
> + * Arm Memory System Resource Partitioning and Monitoring (MPAM) System
> + * Component Specification.
> + * https://developer.arm.com/documentation/ihi0099/latest/
> + */
> +#define MPAM_ARCHITECTURE_V1    0x10
> +
> +/* Memory mapped control pages */
> +/* ID Register offsets in the memory mapped page */
> +#define MPAMF_IDR		0x0000  /* features id register */
> +#define MPAMF_IIDR		0x0018  /* implementer id register */
> +#define MPAMF_AIDR		0x0020  /* architectural id register */
> +#define MPAMF_IMPL_IDR		0x0028  /* imp-def partitioning */
> +#define MPAMF_CPOR_IDR		0x0030  /* cache-portion partitioning */
> +#define MPAMF_CCAP_IDR		0x0038  /* cache-capacity partitioning */
> +#define MPAMF_MBW_IDR		0x0040  /* mem-bw partitioning */
> +#define MPAMF_PRI_IDR		0x0048  /* priority partitioning */
> +#define MPAMF_MSMON_IDR		0x0080  /* performance monitoring features */
> +#define MPAMF_CSUMON_IDR	0x0088  /* cache-usage monitor */
> +#define MPAMF_MBWUMON_IDR	0x0090  /* mem-bw usage monitor */
> +#define MPAMF_PARTID_NRW_IDR	0x0050  /* partid-narrowing */
> +
> +/* Configuration and Status Register offsets in the memory mapped page */
> +#define MPAMCFG_PART_SEL	0x0100  /* partid to configure */
> +#define MPAMCFG_CPBM		0x1000  /* cache-portion config */
> +#define MPAMCFG_CMAX		0x0108  /* cache-capacity config */
> +#define MPAMCFG_CMIN		0x0110  /* cache-capacity config */
> +#define MPAMCFG_CASSOC		0x0118  /* cache-associativity config */
> +#define MPAMCFG_MBW_MIN		0x0200  /* min mem-bw config */
> +#define MPAMCFG_MBW_MAX		0x0208  /* max mem-bw config */
> +#define MPAMCFG_MBW_WINWD	0x0220  /* mem-bw accounting window config */
> +#define MPAMCFG_MBW_PBM		0x2000  /* mem-bw portion bitmap config */
> +#define MPAMCFG_PRI		0x0400  /* priority partitioning config */
> +#define MPAMCFG_MBW_PROP	0x0500  /* mem-bw stride config */
> +#define MPAMCFG_INTPARTID	0x0600  /* partid-narrowing config */
> +
> +#define MSMON_CFG_MON_SEL	0x0800  /* monitor selector */
> +#define MSMON_CFG_CSU_FLT	0x0810  /* cache-usage monitor filter */
> +#define MSMON_CFG_CSU_CTL	0x0818  /* cache-usage monitor config */
> +#define MSMON_CFG_MBWU_FLT	0x0820  /* mem-bw monitor filter */
> +#define MSMON_CFG_MBWU_CTL	0x0828  /* mem-bw monitor config */
> +#define MSMON_CSU		0x0840  /* current cache-usage */
> +#define MSMON_CSU_CAPTURE	0x0848  /* last cache-usage value captured */
> +#define MSMON_MBWU		0x0860  /* current mem-bw usage value */
> +#define MSMON_MBWU_CAPTURE	0x0868  /* last mem-bw value captured */
> +#define MSMON_MBWU_L		0x0880  /* current long mem-bw usage value */
> +#define MSMON_MBWU_CAPTURE_L	0x0890  /* last long mem-bw value captured */
> +#define MSMON_CAPT_EVNT		0x0808  /* signal a capture event */
> +#define MPAMF_ESR		0x00F8  /* error status register */
> +#define MPAMF_ECR		0x00F0  /* error control register */
> +
> +/* MPAMF_IDR - MPAM features ID register */
> +#define MPAMF_IDR_PARTID_MAX		GENMASK(15, 0)
> +#define MPAMF_IDR_PMG_MAX		GENMASK(23, 16)
> +#define MPAMF_IDR_HAS_CCAP_PART		BIT(24)
> +#define MPAMF_IDR_HAS_CPOR_PART		BIT(25)
> +#define MPAMF_IDR_HAS_MBW_PART		BIT(26)
> +#define MPAMF_IDR_HAS_PRI_PART		BIT(27)
> +#define MPAMF_IDR_EXT			BIT(28)
> +#define MPAMF_IDR_HAS_IMPL_IDR		BIT(29)
> +#define MPAMF_IDR_HAS_MSMON		BIT(30)
> +#define MPAMF_IDR_HAS_PARTID_NRW	BIT(31)
> +#define MPAMF_IDR_HAS_RIS		BIT(32)
> +#define MPAMF_IDR_HAS_EXTD_ESR		BIT(38)
> +#define MPAMF_IDR_HAS_ESR		BIT(39)
> +#define MPAMF_IDR_RIS_MAX		GENMASK(59, 56)
> +
> +/* MPAMF_MSMON_IDR - MPAM performance monitoring ID register */
> +#define MPAMF_MSMON_IDR_MSMON_CSU		BIT(16)
> +#define MPAMF_MSMON_IDR_MSMON_MBWU		BIT(17)
> +#define MPAMF_MSMON_IDR_HAS_LOCAL_CAPT_EVNT	BIT(31)
> +
> +/* MPAMF_CPOR_IDR - MPAM features cache portion partitioning ID register */
> +#define MPAMF_CPOR_IDR_CPBM_WD			GENMASK(15, 0)
> +
> +/* MPAMF_CCAP_IDR - MPAM features cache capacity partitioning ID register */
> +#define MPAMF_CCAP_IDR_CMAX_WD			GENMASK(5, 0)
> +#define MPAMF_CCAP_IDR_CASSOC_WD		GENMASK(12, 8)
> +#define MPAMF_CCAP_IDR_HAS_CASSOC		BIT(28)
> +#define MPAMF_CCAP_IDR_HAS_CMIN			BIT(29)
> +#define MPAMF_CCAP_IDR_NO_CMAX			BIT(30)
> +#define MPAMF_CCAP_IDR_HAS_CMAX_SOFTLIM		BIT(31)
> +
> +/* MPAMF_MBW_IDR - MPAM features memory bandwidth partitioning ID register */
> +#define MPAMF_MBW_IDR_BWA_WD		GENMASK(5, 0)
> +#define MPAMF_MBW_IDR_HAS_MIN		BIT(10)
> +#define MPAMF_MBW_IDR_HAS_MAX		BIT(11)
> +#define MPAMF_MBW_IDR_HAS_PBM		BIT(12)
> +#define MPAMF_MBW_IDR_HAS_PROP		BIT(13)
> +#define MPAMF_MBW_IDR_WINDWR		BIT(14)
> +#define MPAMF_MBW_IDR_BWPBM_WD		GENMASK(28, 16)
> +
> +/* MPAMF_PRI_IDR - MPAM features priority partitioning ID register */
> +#define MPAMF_PRI_IDR_HAS_INTPRI	BIT(0)
> +#define MPAMF_PRI_IDR_INTPRI_0_IS_LOW	BIT(1)
> +#define MPAMF_PRI_IDR_INTPRI_WD		GENMASK(9, 4)
> +#define MPAMF_PRI_IDR_HAS_DSPRI		BIT(16)
> +#define MPAMF_PRI_IDR_DSPRI_0_IS_LOW	BIT(17)
> +#define MPAMF_PRI_IDR_DSPRI_WD		GENMASK(25, 20)
> +
> +/* MPAMF_CSUMON_IDR - MPAM cache storage usage monitor ID register */
> +#define MPAMF_CSUMON_IDR_NUM_MON	GENMASK(15, 0)
> +#define MPAMF_CSUMON_IDR_HAS_OFLOW_CAPT	BIT(24)
> +#define MPAMF_CSUMON_IDR_HAS_CEVNT_OFLW	BIT(25)
> +#define MPAMF_CSUMON_IDR_HAS_OFSR	BIT(26)
> +#define MPAMF_CSUMON_IDR_HAS_OFLOW_LNKG	BIT(27)
> +#define MPAMF_CSUMON_IDR_HAS_XCL	BIT(29)
> +#define MPAMF_CSUMON_IDR_CSU_RO		BIT(30)
> +#define MPAMF_CSUMON_IDR_HAS_CAPTURE	BIT(31)
> +
> +/* MPAMF_MBWUMON_IDR - MPAM memory bandwidth usage monitor ID register */
> +#define MPAMF_MBWUMON_IDR_NUM_MON	GENMASK(15, 0)
> +#define MPAMF_MBWUMON_IDR_HAS_RWBW	BIT(28)
> +#define MPAMF_MBWUMON_IDR_LWD		BIT(29)
> +#define MPAMF_MBWUMON_IDR_HAS_LONG	BIT(30)
> +#define MPAMF_MBWUMON_IDR_HAS_CAPTURE	BIT(31)
> +
> +/* MPAMF_PARTID_NRW_IDR - MPAM PARTID narrowing ID register */
> +#define MPAMF_PARTID_NRW_IDR_INTPARTID_MAX	GENMASK(15, 0)
> +
> +/* MPAMF_IIDR - MPAM implementation ID register */
> +#define MPAMF_IIDR_IMPLEMENTER	GENMASK(11, 0)
> +#define MPAMF_IIDR_REVISION	GENMASK(15, 12)
> +#define MPAMF_IIDR_VARIANT	GENMASK(19, 16)
> +#define MPAMF_IIDR_PRODUCTID	GENMASK(31, 20)

Just a friendly reminder:

v2 defines _SHIFTs for each field in MPAMF_IIDR. They are removed here 
but will be used in the 2nd series.

It's not an issue for this series but just a friendly reminder to add 
them back in the 2nd series or the mpam/snapshot/6.18-rc1 cannot be built.

[SNIP]

Thanks.

-Fenghua

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