Re: [PATCH v6 2/2] drivers/perf: hisi: Add driver for HiSilicon PCIe PMU

From: Will Deacon <will@kernel.org>
To: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Cc: Qi Liu <liuqi115@huawei.com>,
	mark.rutland@arm.com, bhelgaas@google.com,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linuxarm@huawei.com,
	zhangshaokun@hisilicon.com
Subject: Re: [PATCH v6 2/2] drivers/perf: hisi: Add driver for HiSilicon PCIe PMU
Date: Tue, 15 Jun 2021 10:26:02 +0100	[thread overview]
Message-ID: <20210615092601.GA19878@willie-the-truck> (raw)
In-Reply-To: <20210614102025.0000222b@Huawei.com>

On Mon, Jun 14, 2021 at 10:20:25AM +0100, Jonathan Cameron wrote:
> On Fri, 11 Jun 2021 17:23:48 +0100
> Will Deacon <will@kernel.org> wrote:
> 
> > On Mon, May 31, 2021 at 09:32:31PM +0800, Qi Liu wrote:
> > > PCIe PMU Root Complex Integrated End Point(RCiEP) device is supported
> > > to sample bandwidth, latency, buffer occupation etc.
> > > 
> > > Each PMU RCiEP device monitors multiple Root Ports, and each RCiEP is
> > > registered as a PMU in /sys/bus/event_source/devices, so users can
> > > select target PMU, and use filter to do further sets.
> > > 
> > > Filtering options contains:
> > > event        - select the event.
> > > subevent     - select the subevent.
> > > port         - select target Root Ports. Information of Root Ports
> > >                are shown under sysfs.
> > > bdf          - select requester_id of target EP device.
> > > trig_len     - set trigger condition for starting event statistics.
> > > trigger_mode - set trigger mode. 0 means starting to statistic when
> > >                bigger than trigger condition, and 1 means smaller.
> > > thr_len      - set threshold for statistics.
> > > thr_mode     - set threshold mode. 0 means count when bigger than
> > >                threshold, and 1 means smaller.
> > > 
> > > Reviewed-by: John Garry <john.garry@huawei.com>
> > > Signed-off-by: Qi Liu <liuqi115@huawei.com>
> > > ---
> > >  MAINTAINERS                                |    6 +
> > >  drivers/perf/Kconfig                       |    2 +
> > >  drivers/perf/Makefile                      |    1 +
> > >  drivers/perf/pci/Kconfig                   |   16 +
> > >  drivers/perf/pci/Makefile                  |    2 +
> > >  drivers/perf/pci/hisilicon/Makefile        |    3 +
> > >  drivers/perf/pci/hisilicon/hisi_pcie_pmu.c | 1019 ++++++++++++++++++++++++++++  
> > 
> > Can we keep this under drivers/perf/hisilicon/ please? I don't see the
> > need to create a 'pci' directory here.
> 
> https://lore.kernel.org/linux-pci/20190103154439.GC16311@edgewater-inn.cambridge.arm.com/
> 
> Discussion back in 2018 about where to put these...

I don't remember that at all :)

> Though, perf/pci/hisilicon does seem over the top in terms of depth, maybe perf/pci/
> or just give up on that plan and put them (for now at least) in per company directories.

I think perf/hisilicon makes the most sense. We can always move it later
if we need to.

Will