drivers/perf/arm_cspmu · keep

Arm CoreSight Architecture System Performance Monitoring Units

Performance monitoring units built into modern Arm server-class systems-on-chip following Arm's CoreSight System PMU architecture. They expose hardware event counters for things like memory controllers and interconnects to the perf tool, and ship in current server silicon including NVIDIA's Grace CPUs and Ampere's AmpereOne processors.

keep conf=0.90 deploy=medium replacement=none subsystem=perf category=infrastructure

90%

recommendation

It should stay in the kernel because the hardware is brand new and actively sold: NVIDIA Grace and Ampere's AmpereOne lineup both rely on it, and the code itself was still receiving feature patches as recently as September 2025, including vendor-specific extensions for NVIDIA and new architectural fields like PMPIDR. There is no sign of deprecation activity upstream.

repository signals

6 files

2,415 source lines

41 commits, 5y

+2,904 / −450 lines added / removed, 5y

12 authors, 5y

monthly commits · 2021-04-21 → 2026-04-21 · 41 total · active in 15/61 months

sources

spinics.net
September 30, 2025 patch traffic shows arm_cspmu still receiving feature work upstream (PMPIDR support).
spinics.net
September 30, 2025 patch traffic shows nvidia_cspmu still receiving vendor-specific feature work upstream (PMEVFILTR2 support).
kernel.org
Upstream kernel docs describe this driver family as supporting Ampere SoC PMU, initially for AmpereOne MCU events.
docs.nvidia.com
NVIDIA's current Grace performance guide documents multiple CoreSight System PMUs exposed through this driver family and how to use them with perf.
amperecomputing.com
Ampere's current processor lineup still markets AmpereOne and AmpereOne M platforms, indicating supported hardware remains commercially active.

codex reasoning notes (technical)

Real driver directory: local shell inspection found platform_driver/module_init code and Kconfig entries for generic, NVIDIA, and Ampere backends. Local git log showed substantive arm_cspmu commits through 2025-11-03. Source URLs were obtained via web search: two spinics mailing-list pages for recent upstream patch traffic, kernel.org perf admin-guide page for AmpereOne support, NVIDIA Grace perf guide for active deployed PMUs, and Ampere's product page for ongoing sales. Available web/lore-style queries did not surface a removal/deprecation thread; with active 2025 maintenance plus current Grace/AmpereOne products, removal or deprecation is not indicated.