Re: [PATCH 1/3] drivers/perf: hisi: Consolidate uncore PMU cpuhp states

[Jonathan Cameron]

On Mon, 27 Jul 2026 13:41:59 +0100
Robin Murphy <robin.murphy@xxxxxxx> wrote:

> On 24/07/2026 3:52 am, Yushan Wang wrote:
> > Every HiSilicon uncore PMU driver allocates its own static cpuhp state
> > even though they all register identical online/offline callbacks. This
> > wastes slots in the cpuhp state enum and needlessly fragments the
> > hotplug state space.
> > 
> > Move the cpuhp state setup into the shared hisi_uncore_pmu framework:
> > register a single dynamic state (CPUHP_AP_ONLINE_DYN) at framework
> > module init and export it for all HiSilicon uncore PMU drivers to use.
> > Drop the now-unused static CPUHP_AP_PERF_ARM_HISI_* entries from
> > include/linux/cpuhotplug.h.
> > 
> > The L3C PMU driver keeps a private dynamic state because it has its own
> > hotplug callbacks for migrating multiple per-CPU interrupt affinities,
> > but switches from its former static slot to CPUHP_AP_ONLINE_DYN for
> > consistency.
> > 
> > No intended functional changes.
> > 
> > Signed-off-by: Yushan Wang <wangyushan12@xxxxxxxxxx>
> > ---
> >   drivers/perf/hisilicon/hisi_uncore_cpa_pmu.c  | 34 +++---------------
> >   drivers/perf/hisilicon/hisi_uncore_ddrc_pmu.c | 34 +++---------------
> >   drivers/perf/hisilicon/hisi_uncore_hha_pmu.c  | 34 +++---------------
> >   drivers/perf/hisilicon/hisi_uncore_l3c_pmu.c  | 21 +++++------
> >   drivers/perf/hisilicon/hisi_uncore_mn_pmu.c   | 35 ++----------------
> >   drivers/perf/hisilicon/hisi_uncore_noc_pmu.c  | 35 ++----------------
> >   drivers/perf/hisilicon/hisi_uncore_pa_pmu.c   | 34 +++---------------
> >   drivers/perf/hisilicon/hisi_uncore_pmu.c      | 25 +++++++++++++
> >   drivers/perf/hisilicon/hisi_uncore_pmu.h      |  2 ++
> >   drivers/perf/hisilicon/hisi_uncore_sllc_pmu.c | 34 +++---------------
> >   drivers/perf/hisilicon/hisi_uncore_uc_pmu.c   | 36 ++-----------------
> >   include/linux/cpuhotplug.h                    |  6 ----
> >   12 files changed, 67 insertions(+), 263 deletions(-)  
> 
> Neat! Seems like a pretty nice win already, plus it only makes a 
> conversion easier if my generic hotplug idea takes off :)
> 
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
Hi Yushan,

Nice indeed.  It always irritated me to see that block of code cut
and paste so often + that it stopped use of module_platform_driver()

Reviewed-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxxxxxxxx>