Hello, This is just enough MPAM driver for the ACPI and DT pre-requisites. It doesn't contain any of the resctrl code, meaning you can't actually drive it from user-space yet. Becuase of that, its hidden behind CONFIG_EXPERT. This will change once the user interface is connected up. This is the initial group of patches that allows the resctrl code to be built on top. Including that will increase the number of trees that may need to coordinate, so breaking it up make sense. The locking looks very strange - but is influenced by the 'mpam-fb' firmware interface specification that is still alpha. That thing needs to wait for an interrupt after every system register write, which significantly impacts the driver. Some features just won't work, e.g. reading the monitor registers via perf. The aim is to not have to make invasive changes to the locking to support the firmware interface, hence it looks strange from day-1. I've not found a platform that can test all the behaviours around the monitors, so this is where I'd expect the most bugs. The MPAM spec that describes all the system and MMIO registers can be found here: https://developer.arm.com/documentation/ddi0598/db/?lang=en (Ignored the 'RETIRED' warning - that is just arm moving the documentation around. This document has the best overview) The expectation is this will go via the arm64 tree. This series is based on v6.17-rc2, and can be retrieved from: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git mpam/driver/rv1 The rest of the driver can be found here: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git mpam/snapshot/v6.17-rc2 What is MPAM? Set your time-machine to 2020: https://lore.kernel.org/lkml/20201030161120.227225-1-james.morse@xxxxxxx/ This series was previously posted here: [RFC] lore.kernel.org/r/20250711183648.30766-2-james.morse@xxxxxxx Bugs welcome, Thanks, James Morse (29): cacheinfo: Expose the code to generate a cache-id from a device_node drivers: base: cacheinfo: Add helper to find the cache size from cpu+level ACPI / PPTT: Add a helper to fill a cpumask from a processor container ACPI / PPTT: Stop acpi_count_levels() expecting callers to clear levels ACPI / PPTT: Find cache level by cache-id ACPI / PPTT: Add a helper to fill a cpumask from a cache_id arm64: kconfig: Add Kconfig entry for MPAM ACPI / MPAM: Parse the MPAM table arm_mpam: Add probe/remove for mpam msc driver and kbuild boiler plate arm_mpam: Add the class and component structures for ris firmware described arm_mpam: Add MPAM MSC register layout definitions arm_mpam: Add cpuhp callbacks to probe MSC hardware arm_mpam: Probe MSCs to find the supported partid/pmg values arm_mpam: Add helpers for managing the locking around the mon_sel registers arm_mpam: Probe the hardware features resctrl supports arm_mpam: Merge supported features during mpam_enable() into mpam_class arm_mpam: Reset MSC controls from cpu hp callbacks arm_mpam: Add a helper to touch an MSC from any CPU arm_mpam: Extend reset logic to allow devices to be reset any time arm_mpam: Register and enable IRQs arm_mpam: Use a static key to indicate when mpam is enabled arm_mpam: Allow configuration to be applied and restored during cpu online arm_mpam: Probe and reset the rest of the features arm_mpam: Add helpers to allocate monitors arm_mpam: Add mpam_msmon_read() to read monitor value arm_mpam: Track bandwidth counter state for overflow and power management arm_mpam: Add helper to reset saved mbwu state arm_mpam: Add kunit test for bitmap reset arm_mpam: Add kunit tests for props_mismatch() Rob Herring (1): dt-bindings: arm: Add MPAM MSC binding Rohit Mathew (2): arm_mpam: Probe for long/lwd mbwu counters arm_mpam: Use long MBWU counters if supported Shanker Donthineni (1): arm_mpam: Add support for memory controller MSC on DT platforms .../devicetree/bindings/arm/arm,mpam-msc.yaml | 200 ++ arch/arm64/Kconfig | 19 + drivers/Kconfig | 2 + drivers/Makefile | 1 + drivers/acpi/arm64/Kconfig | 3 + drivers/acpi/arm64/Makefile | 1 + drivers/acpi/arm64/mpam.c | 331 ++ drivers/acpi/pptt.c | 230 +- drivers/acpi/tables.c | 2 +- drivers/base/cacheinfo.c | 19 +- drivers/resctrl/Kconfig | 24 + drivers/resctrl/Makefile | 4 + drivers/resctrl/mpam_devices.c | 2909 +++++++++++++++++ drivers/resctrl/mpam_internal.h | 692 ++++ drivers/resctrl/test_mpam_devices.c | 390 +++ include/linux/acpi.h | 26 + include/linux/arm_mpam.h | 56 + include/linux/cacheinfo.h | 16 + 18 files changed, 4911 insertions(+), 14 deletions(-) create mode 100644 Documentation/devicetree/bindings/arm/arm,mpam-msc.yaml create mode 100644 drivers/acpi/arm64/mpam.c create mode 100644 drivers/resctrl/Kconfig create mode 100644 drivers/resctrl/Makefile create mode 100644 drivers/resctrl/mpam_devices.c create mode 100644 drivers/resctrl/mpam_internal.h create mode 100644 drivers/resctrl/test_mpam_devices.c create mode 100644 include/linux/arm_mpam.h -- 2.20.1
