On Wed, Feb 12, 2020 at 06:02:11PM +0800, Wu Hao wrote:

On Tue, Feb 11, 2020 at 09:30:35PM -0800, Greg KH wrote:

quoted

On Wed, Feb 12, 2020 at 11:19:29AM +0800, Wu Hao wrote:

quoted

On Mon, Feb 10, 2020 at 04:34:01PM +0000, Will Deacon wrote:

quoted

Hi,

On Mon, Feb 10, 2020 at 11:47:49AM +0800, Wu Hao wrote:

quoted

This patch adds support for performance reporting private feature
for FPGA Management Engine (FME). Now it supports several different
performance counters, including 'basic', 'cache', 'fabric', 'vtd'
and 'vtd_sip'. It allows user to use standard linux tools to access
these performance counters.

I had a quick look at this, and it mostly looks alright to me. Just a few
high-level comments/questions:

Hi Will

Thanks a lot for the review! :)

quoted

  - I would still prefer for the PMU drivers to live under drivers/perf/

Hm.. one possible way is to create a platform device, and introduce a new
platform device driver under drivers/perf/.

No, do not abuse platform drivers, you have a real device, use it.

Sure, thanks for the comments. Then I don't have any other idea to move code to
drivers/perf/ directory, so probably only can live with current code.

The location of the file in the kernel tree has no bearing on if you use
a platform device, a USB device, or a PCI device.  It is just a location
of a file.

You are interacting with the perf api as the driver's primary userspace
api, so put the driver into the drivers/perf/ directory.  That's all
that Will is asking you to do here.

greg k-h