Subject: Re: linux-next: manual merge of the kvm-arm tree with the arm-perf tree

From: Oliver Upton <[email-masked]>
Date: Wed, 12 Mar 2025 10:07:52 -0700

On Wed, Mar 12, 2025 at 12:45:02PM +0000, Will Deacon wrote:
> On Wed, Mar 12, 2025 at 08:18:53PM +1100, Stephen Rothwell wrote:
> > Hi all,
> > 
> > Today's linux-next merge of the kvm-arm tree got a conflict in:
> > 
> >   drivers/perf/apple_m1_cpu_pmu.c
> > 
> > between commit:
> > 
> >   c2e793da59fc ("perf: apple_m1: Don't disable counter in m1_pmu_enable_event()")
> > 
> > from the arm-perf tree and commit:
> > 
> >   75ecffc361bb ("drivers/perf: apple_m1: Refactor event select/filter configuration")
> > 
> > from the kvm-arm tree.
> > 
> > I fixed it up (see below) and can carry the fix as necessary. This
> > is now fixed as far as linux-next is concerned, but any non trivial
> > conflicts should be mentioned to your upstream maintainer when your tree
> > is submitted for merging.  You may also want to consider cooperating
> > with the maintainer of the conflicting tree to minimise any particularly
> > complex conflicts.
> > 
> > -- 
> > Cheers,
> > Stephen Rothwell
> > 
> > diff --cc drivers/perf/apple_m1_cpu_pmu.c
> > index 39349ecec3c1,6be703619a97..000000000000
> > --- a/drivers/perf/apple_m1_cpu_pmu.c
> > +++ b/drivers/perf/apple_m1_cpu_pmu.c
> > @@@ -396,7 -428,11 +428,7 @@@ static void m1_pmu_enable_event(struct 
> >   	user = event->hw.config_base & M1_PMU_CFG_COUNT_USER;
> >   	kernel = event->hw.config_base & M1_PMU_CFG_COUNT_KERNEL;
> >   
> > - 	m1_pmu_configure_counter(event->hw.idx, evt, user, kernel);
> >  -	m1_pmu_disable_counter_interrupt(event->hw.idx);
> >  -	m1_pmu_disable_counter(event->hw.idx);
> >  -	isb();
> >  -
> > + 	m1_pmu_configure_counter(event->hw.idx, event->hw.config_base);
> >   	m1_pmu_enable_counter(event->hw.idx);
> >   	m1_pmu_enable_counter_interrupt(event->hw.idx);
> >   	isb();
> 
> Looks fine to me but I'd also be happy to stick the first two patches
> on a shared branch to avoid this. Oliver?

Agreed!

  git://git.kernel.org/pub/scm/linux/kernel/git/oupton/linux.git perf/m1-guest-events

Thanks,
Oliver