Re: [PATCH v3 09/29] arm_mpam: Add MPAM MSC register layout definitions

From: Fenghua Yu
Date: Fri Oct 17 2025 - 19:03:53 EST

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@xxxxxxx>
Reviewed-by: Ben Horgan <ben.horgan@xxxxxxx>
Reviewed-by: Fenghua Yu <fenghuay@xxxxxxxxxx>
Tested-by: Fenghua Yu <fenghuay@xxxxxxxxxx>
---
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