[PATCH v13 01/20] ARM64: Move PMU register related defines to asm/perf_event.h

[will.deacon@arm.com (Will Deacon)]

On Mon, Feb 29, 2016 at 01:07:23PM +0000, Marc Zyngier wrote:
> On 25/02/16 02:02, Shannon Zhao wrote:
> > On 2016/2/25 1:52, Will Deacon wrote:
> >> On Wed, Feb 24, 2016 at 01:08:21PM +0800, Shannon Zhao wrote:
> >>> From: Shannon Zhao <shannon.zhao@linaro.org>
> >>>
> >>> To use the ARMv8 PMU related register defines from the KVM code, we move
> >>> the relevant definitions to asm/perf_event.h header file and rename them
> >>> with prefix ARMV8_PMU_.
> >>>
> >>> Signed-off-by: Anup Patel <anup.patel@linaro.org>
> >>> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> >>> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
> >>> Reviewed-by: Andrew Jones <drjones@redhat.com>
> >>> ---
> >>>  arch/arm64/include/asm/perf_event.h | 35 +++++++++++++++++++
> >>>  arch/arm64/kernel/perf_event.c      | 68 ++++++++++---------------------------
> >>>  2 files changed, 52 insertions(+), 51 deletions(-)
> >>
> >> Looks fine to me, but we're going to get some truly horrible conflicts
> >> in -next.
> >>
> >> I'm open to suggestions on the best way to handle this, but one way
> >> would be:
> >>
> >>   1. Duplicate all the #defines privately in KVM (queue via kvm tree)
> > This way seems not proper I think.
> > 
> >>   2. Rebase this patch onto my perf/updates branch [1] (queue via me)
> > While to this series, it really relies on the perf_event.h to compile
> > and test, so maybe for KVM-ARM and KVM maintainers it's not proper.
> > 
> >>   3. Patch at -rc1 dropping the #defines from (1) and moving to the new
> >>      perf_event.h stuff
> >>
> > I vote for this way. Since the patch in [1] is small and nothing else
> > relies on them, I think it would be simple to rebase them onto this series.
> > 
> >> Thoughts?
> >>
> > Anyway, there are only 3 lines which have conflicts. I'm not sure
> > whether we could handle this when we merge them.
> 
> I think you're missing the point:
> 
> - We want both the arm64 perf and KVM trees to be easy to merge
> - The conflicts are not that simple to resolve
> - We want these conflicts to be solved before it hits Linus' tree
> 
> With that in mind, here's what I'm suggesting we merge as a first patch:
> 
> https://git.kernel.org/cgit/linux/kernel/git/kvmarm/kvmarm.git/commit/?h=queue&id=2029b4b02691ec6ebba3d281068e783353d7e108

Acked-by: Will Deacon <will.deacon@arm.com>

Will