Re: [dpdk-dev] [PATCH v2 1/7] lib/librte_pci: add rte_pci_regs.h

[Thomas Monjalon <thomas@monjalon.net>]

16/07/2020 15:02, Jerin Jacob:
> On Thu, Jul 16, 2020 at 6:20 PM Thomas Monjalon <thomas@monjalon.net> wrote:
> >
> > 16/07/2020 13:55, Jerin Jacob:
> > > On Thu, Jul 16, 2020 at 4:57 PM Thomas Monjalon <thomas@monjalon.net> wrote:
> > > >
> > > > 16/07/2020 12:27, Jerin Jacob:
> > > > > On Thu, Jul 16, 2020 at 3:48 PM Gaëtan Rivet <grive@u256.net> wrote:
> > > > > >
> > > > > > On 16/07/20 12:08 +0200, Gaëtan Rivet wrote:
> > > > > > > Re-CCing dev@dpdk.org as it was removed from the reply.
> > > > > > >
> > > > > > > On 13/07/20 08:13 -0700, Manish Chopra wrote:
> > > > > > > > This is merely copy of latest linux/pci_regs.h in
> > > > > > > > order to avoid dependency of dpdk on user headers.
> > > > > > > >
> > > > > > >
> > > > > > > I guess this dependency is an issue on non-linux systems, when you must
> > > > > > > use those defines in a generic implementation. Can you confirm this is
> > > > > > > the motivation here?
> > > > > > >
> > > > > > > If so, I think it would be clearer to state "in order to avoid
> > > > > > > dependency of DPDK on linux headers".
> > > > > > >
> > > > > >
> > > > > > To add to it, if this is actually the motivation to add this header, I
> > > > > > don't think it is sufficient.
> > > > > >
> > > > > > You can restrict the function definition to the linux part of the
> > > > > > PCI bus driver instead, using stubs for other systems.
> > > > > >
> > > > > > > > Signed-off-by: Manish Chopra <manishc@marvell.com>
> > > > > > > > Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
> > > > > > > > ---
> > > > > > > >  drivers/bus/pci/linux/pci_uio.c     |    2 +-
> > > > > > > >  drivers/bus/pci/linux/pci_vfio.c    |    2 +-
> > > > > > > >  drivers/net/bnx2x/bnx2x.h           |    2 +-
> > > > > > > >  drivers/net/hns3/hns3_ethdev_vf.c   |    2 +-
> > > > > > > >  drivers/vdpa/ifc/base/ifcvf_osdep.h |    2 +-
> > > > > > > >  lib/librte_pci/Makefile             |    1 +
> > > > > > > >  lib/librte_pci/meson.build          |    2 +-
> > > > > > > >  lib/librte_pci/rte_pci_regs.h       | 1075 +++++++++++++++++++++++++++
> > > > > > > >  8 files changed, 1082 insertions(+), 6 deletions(-)
> > > > > > > >  create mode 100644 lib/librte_pci/rte_pci_regs.h
> > > > > > > >
> > > > > > >
> > > > > > > [...]
> > > > > > >
> > > > > > > > diff --git a/lib/librte_pci/rte_pci_regs.h b/lib/librte_pci/rte_pci_regs.h
> > > > > > > > new file mode 100644
> > > > > > > > index 000000000..1d11f4de5
> > > > > > > > --- /dev/null
> > > > > > > > +++ b/lib/librte_pci/rte_pci_regs.h
> > > > > > > > @@ -0,0 +1,1075 @@
> > > > > > > > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> > > > > > > > +/*
> > > > > > >
> > > > > > > This file is delivered alongside the PCI lib, targeting userspace.
> > > > > > > This seems to be an exception to the license policy described in
> > > > > > > license/README. Code shared between kernel and userspace is expected
> > > > > > > to be dual-licensed BSD-3 and GPL-2.0.
> > > > > > >
> > > > > > > As it is a copy of Linux user includes, re-licensing it as BSD-3 as well
> > > > > > > is not possible.
> > > > > > >
> > > > > > > So I think it might require a techboard + governing board exception
> > > > > > > approval. Ferruh or Thomas, what do you think?
> > > > >
> > > > > I think, instead of importing GPL-2.0 file, We can add the constants
> > > > > as need by the DPDK
> > > > > as symbols start from RTE_PCI_*(It will fix up the namespace as well).
> > > >
> > > > If symbols can be found in /usr/include/, don't add anything.
> > >
> > > Not by default on all the distros. It is part of pciutils library.
> > > Moreover, we need these symbols for Windows OS as well.
> > > IMO, We should add absolute minimum constants that needed for DPDK as RTE_PCI_*
> >
> > I am for mandating the dependency instead of copying it.
> 
> You mean _pciutils_ package as a mandatory dependency to  DPDK.

There is already this dependency:
	#include <linux/pci_regs.h>
I'm missing the real justification for this patch.
Is there some missing definitions?
Is there some environments where this file is missing?

> > pciutils cannot be installed on Windows?
> > Why do you care about Windows?
> > I don't see any contribution for qede on Windows.
> 
> You closely review the patch, it not about qede. The proposed file
> comes at lib/librte_pci/rte_pci_regs.h which is common to Windows.

The series is for qede. I'm trying to understand the motivation.