Re: [PATCH v9 1/2] uio: uio_dfl: add userspace i/o driver for DFL bus

[Moritz Fischer <mdf@kernel.org>]

On Tue, Jan 26, 2021 at 10:40:05AM +0800, Xu Yilun wrote:
> On Mon, Jan 25, 2021 at 06:22:55PM -0800, Moritz Fischer wrote:
> > On Mon, Jan 25, 2021 at 11:00:38AM -0800, Tom Rix wrote:
> > > 
> > > On 1/25/21 12:49 AM, Xu Yilun wrote:
> > > > This patch supports the DFL drivers be written in userspace. This is
> > > > realized by exposing the userspace I/O device interfaces.
> > > >
> > > > The driver now only binds the ether group feature, which has no irq. So
> > > > the irq support is not implemented yet.
> > > >
> > > > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > > > ---
> > > > v9: switch to add a uio driver in drivers/uio
> > > > ---
> > > >  drivers/uio/Kconfig   | 13 ++++++++++
> > > >  drivers/uio/Makefile  |  1 +
> > > >  drivers/uio/uio_dfl.c | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++
> > > 
> > > You should add this to the MAINTAINERS file.
> > 
> > This is covered by MAINTAINERS under drivers/uio.
> 
> Yes. But is it OK I also add the file in "FPGA DFL DRIVERS"? So DFL
> developers would also be aware if there is change. It is a little
> different from other feature driver, it is like a generic driver for
> DFL bus.
Fair enough. I meant you don't have to if you don't want to. If you want
to feel free to do so :)
> 
> > > 
> > > >  3 files changed, 80 insertions(+)
> > > >  create mode 100644 drivers/uio/uio_dfl.c
> > > >
> > > > diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
> > > > index 202ee81..44778f8 100644
> > > > --- a/drivers/uio/Kconfig
> > > > +++ b/drivers/uio/Kconfig
> > > > @@ -165,4 +165,17 @@ config UIO_HV_GENERIC
> > > >  	  to network and storage devices from userspace.
> > > >  
> > > >  	  If you compile this as a module, it will be called uio_hv_generic.
> > > > +
> > > > +config UIO_DFL
> > > > +	tristate "Generic driver for DFL bus"
> > > 
> > > The term 'DFL' will be unknown to folks in drivers/uio
> > > 
> > > I think it would be better if DFL was always prefixed 'FPGA DFL'
> > > 
> > > > +	depends on FPGA_DFL
> > > > +	help
> > > > +	  Generic DFL (Device Feature List) driver for Userspace I/O devices.
> > > > +	  It is useful to provide direct access to DFL devices from userspace.
> > > > +	  A sample userspace application using this driver is available for
> > > > +	  download in a git repository:
> > > > +
> > > > +	    git clone https://github.com/OPAE/opae-sdk.git
> > > > +
> > > > +	  If you compile this as a module, it will be called uio_dfl.
> > 
> > I'm not sure KConfig is the right place for this.
> 
> Do you mean the OPAE link? I see several uio drivers provide their
> userspace application link in Kconfig. I guess the uio drivers are
> selected for these applications so it may be better pointing out where
> they are.

Ok, works for me.

- Moritz