Re: [PATCH v2 0/3] perf/x86/amd/uncore: Add common helpers and Hygon support

[Sandipan Das]

On 01-07-2026 15:04, Qi Liu wrote:
> This series adds initial Hygon uncore PMU support.
> 
> Hygon uncore PMUs use a programming model close to the AMD uncore PMU,
> so this series factors out a small set of common helpers for perf event
> handling, counter assignment and per-CPU context management.
> 
> The Hygon-specific support is kept in the Hygon driver. This series
> supports the Hygon DF and DF IOD PMUs. No Hygon-specific logic is
> added to the AMD driver.
> 
> Changes since RFC:
>   - Address sashiko bot review.
> Changes since v1:
>   - Rename the helper namespace to amd_uncore_common_* to avoid
>     an generic uncore_common_* prefix, and to keep it distinct
>     from the existing amd_uncore_* names.
> 
> 
> Qi Liu (3):
>   perf/x86/amd/uncore: Add common PMU helper functions
>   perf/x86/amd/uncore: Convert AMD driver to common PMU helpers
>   perf/x86/amd/uncore: Add Hygon uncore PMU support
> 
>  arch/x86/events/Kconfig                 |  17 +
>  arch/x86/events/amd/Makefile            |   4 +
>  arch/x86/events/amd/amd_uncore_common.c | 403 +++++++++++++++++
>  arch/x86/events/amd/amd_uncore_common.h | 114 +++++
>  arch/x86/events/amd/hygon_uncore.c      | 556 +++++++++++++++++++++++
>  arch/x86/events/amd/uncore.c            | 578 +++---------------------
>  arch/x86/include/asm/msr-index.h        |   2 +
>  arch/x86/include/asm/perf_event.h       |  20 +
>  include/linux/cpuhotplug.h              |   3 +
>  9 files changed, 1192 insertions(+), 505 deletions(-)
>  create mode 100644 arch/x86/events/amd/amd_uncore_common.c
>  create mode 100644 arch/x86/events/amd/amd_uncore_common.h
>  create mode 100644 arch/x86/events/amd/hygon_uncore.c
> 

I am trying to understand if the code movement is necessary.
Wouldn't it be sufficient to just add the following?
 - new UNCORE_TYPE_HYGON_DF and UNCORE_TYPE_HYGON_DF_IOD types
 - Hygon-specific attr_groups, pmu->event_init(), pmu->add(),
   amd_uncore->init() and amd_uncore->scan() implementations

Using new PMU names will also require tools-side changes. Additionally,
to make the PMUs actually useful, new JSON events and metrics need to
be added. Are there plans for that?