Re: [PATCH] perf/arm-cmn: Set PMU device parent

From: Jonathan Cameron
Date: Wed Apr 10 2024 - 13:12:39 EST


On Wed, 10 Apr 2024 18:04:03 +0100
Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote:

> On Tue, 9 Apr 2024 18:15:17 +0100
> Robin Murphy <robin.murphy@xxxxxxx> wrote:
>
> > Now that perf supports giving the PMU device a parent, we can use our
> > platform device to make the relationship between CMN instances and PMU
> > IDs trivially discoverable, from either nominal direction:
> >
> > root@crazy-taxi:~# ls /sys/devices/platform/ARMHC600:00 | grep cmn
> > arm_cmn_0
> > root@crazy-taxi:~# realpath /sys/bus/event_source/devices/arm_cmn_0/..
> > /sys/devices/platform/ARMHC600:00
> >
> > Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
> Nice. I'd forgotten all about this :(
>
> https://lore.kernel.org/all/20230404134225.13408-1-Jonathan.Cameron@xxxxxxxxxx/
> still has a bunch of these + there were many I never looked into.
>
> Guess I should respin that series though probably 50% at least still apply.

Ironically other than this one, almost the only ones that didn't go in cleanly
are the hisilicon drivers where there was some churn.

Will, if you 'want' to pick any of those up directly feel free, if not I'll sent
them out again in a few days time (and check there weren't any requests for
changes buried in that rather extensive thread!)

Jonathan

>
> J
>
>
> > ---
> > drivers/perf/arm-cmn.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
> > index 7ef9c7e4836b..b2c607cf3ad7 100644
> > --- a/drivers/perf/arm-cmn.c
> > +++ b/drivers/perf/arm-cmn.c
> > @@ -2482,6 +2482,7 @@ static int arm_cmn_probe(struct platform_device *pdev)
> > cmn->cpu = cpumask_local_spread(0, dev_to_node(cmn->dev));
> > cmn->pmu = (struct pmu) {
> > .module = THIS_MODULE,
> > + .parent = cmn->dev,
> > .attr_groups = arm_cmn_attr_groups,
> > .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
> > .task_ctx_nr = perf_invalid_context,
>
>
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