Re: [PATCH v4 0/8] perf: arm: Make PMUv3 driver available for aarch32

From: Will Deacon <will@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <maz@kernel.org>,
	Zaid Al-Bassam <zalbassam@google.com>,
	Jesus Sanchez-Palencia <jesussanp@google.com>,
	Russell King <linux@armlinux.org.uk>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
	James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu,
	"f.fainelli@gmail.comm Anshuman Khandual"
	<anshuman.khandual@arm.com>
Subject: Re: [PATCH v4 0/8] perf: arm: Make PMUv3 driver available for aarch32
Date: Fri, 24 Mar 2023 18:03:30 +0000	[thread overview]
Message-ID: <20230324180329.GB27948@willie-the-truck> (raw)
In-Reply-To: <ZB2sGrsbr58ttoWI@FVFF77S0Q05N>

On Fri, Mar 24, 2023 at 01:56:42PM +0000, Mark Rutland wrote:
> On Sat, Mar 18, 2023 at 10:02:33AM +0000, Marc Zyngier wrote:
> > On Fri, 17 Mar 2023 19:50:19 +0000,
> > Zaid Al-Bassam <zalbassam@google.com> wrote:
> > > 
> > > Currently, PMUv3 driver is only available for ARMv8 aarch64 platforms,
> > > ARMv8 platorms running in aarch32 mode dont have access to the driver.
> > > This is, especially, a problem for ARMv8 platforms that only have
> > > aarch32 support, like the Cortex-A32.
> > > 
> > > Make the PMUv3 driver available to arm arch (ARMv8 aarch32) by moving
> > > the PMUv3 driver from arm64 to drivers, that makes the driver common
> > > to both arm and arm64 architectures, then add PMUv3 arm Support.
> > > 
> > > The main work in this patchset was made a while back by Marc Zyngier
> > > in [1]. Patchset version 1 [v1] rebases Marc's patches to the latest
> > > kernel revision and adds additional patches to accommodate the changes
> > > in the kernel since Marc wrote the patches.
> > > 
> > > version 2 [v2] of the patchset was created by Marc Zyngier and I
> > > picked it up from [2].
> > 
> > The SoB chain is now a bit off as you picked it from my tree. Nothing
> > that we can't fix, but please be careful in the future. You also
> > failed to pick Florian's Tested-by: tags, which is worse. Please make
> > sure to pick these things as people reply to your series.
> > 
> > Will, Mark: any objection to the general shape of this series? I've
> > been using it again to test the 32bit PMU support in KVM, and would
> > rather see something merged while the architecture still has some
> > relevance.
> 
> I think the general shape looks fine, but this is going to conflict with
> Anshuman's BRBE series, so we'll need to figure out how to stage these w.r.t.
> one another.
> 
> Will, any preference between handling the merge manually or rebasing one atop
> the other? We'll presumably want to place the BRBE files under drivers/perf/ if
> we've moved the PMUv3 code there.

Probably easiest to queue this and have Anshuman rebase BRBE on top once
I've done that. I'll look at it next week.

Will