> -----Original Message----- > From: dev <dev-boun...@dpdk.org> On Behalf Of Manish Chopra > Sent: Friday, July 17, 2020 2:19 AM > To: Gaëtan Rivet <gr...@u256.net>; Thomas Monjalon > <tho...@monjalon.net> > Cc: Jerin Jacob <jerinjac...@gmail.com>; Ferruh Yigit > <ferruh.yi...@intel.com>; Igor Russkikh <irussk...@marvell.com>; dpdk-dev > <dev@dpdk.org> > Subject: Re: [dpdk-dev] [EXT] Re: [PATCH v2 1/7] lib/librte_pci: add > rte_pci_regs.h > > > -----Original Message----- > > From: Gaëtan Rivet <gr...@u256.net> > > Sent: Thursday, July 16, 2020 11:26 PM > > To: Thomas Monjalon <tho...@monjalon.net> > > Cc: Jerin Jacob <jerinjac...@gmail.com>; Manish Chopra > > <mani...@marvell.com>; Ferruh Yigit <ferruh.yi...@intel.com>; Igor > > Russkikh <irussk...@marvell.com>; dpdk-dev <dev@dpdk.org> > > Subject: [EXT] Re: [dpdk-dev] [PATCH v2 1/7] lib/librte_pci: add > > rte_pci_regs.h > > > > External Email > > > > ---------------------------------------------------------------------- > > On 16/07/20 18:57 +0200, Thomas Monjalon wrote: > > > 16/07/2020 18:43, Jerin Jacob: > > > > On Thu, Jul 16, 2020 at 9:25 PM Thomas Monjalon > > <tho...@monjalon.net> wrote: > > > > > > > > > > 16/07/2020 15:02, Jerin Jacob: > > > > > > On Thu, Jul 16, 2020 at 6:20 PM Thomas Monjalon > > <tho...@monjalon.net> wrote: > > > > > > > > > > > > > > 16/07/2020 13:55, Jerin Jacob: > > > > > > > > On Thu, Jul 16, 2020 at 4:57 PM Thomas Monjalon > > <tho...@monjalon.net> wrote: > > > > > > > > > > > > > > > > > > 16/07/2020 12:27, Jerin Jacob: > > > > > > > > > > On Thu, Jul 16, 2020 at 3:48 PM Gaëtan Rivet > > <gr...@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 > > > > > > > > > > > > > <mani...@marvell.com> > > > > > > > > > > > > > Signed-off-by: Igor Russkikh > > > > > > > > > > > > > <irussk...@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 just checked in archlinux, PCI headers can be provided by > > > > > > > > # pacman -F /usr/include/pci/header.h usr/include/pci/header.h is > > > > owned by core/pciutils 3.7.0- > > > > > > > > # pacman -F /usr/include/linux/pci.h usr/include/linux/pci.h is > > > > owned by core/linux-api-headers 5.4.17-1 > > > > > > > > > > > > > I'm missing the real justification for this patch. > > > > > > > > See below. > > > > > > > > > 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. > > > > > > > > First version of qede driver sent with defined generic PCI symbols > > > > and generic PCI function like pci_find_next_ext_capability() in > > > > qede > > driver. > > > > > > That's a pity the v2 is not threaded with v1, I would have found > > > these explanations easily myself. > > > > > > > In the review, I suggested using generic rte_ function as > > > > a) It is not specific to qede. > > > > b) Other drivers also doing the same thing in their own driver > > > > space as there is no dpdk API for the same. > > > > This patches create generic API for pci_find_next_ext_capability() > > > > and remove duplicate implementation from the drivers. > > > > https://urldefense.proofpoint.com/v2/url?u=http-3A__patches.dpdk.o > > > > rg > > > > > > > _patch_73959_&d=DwIDaQ&c=nKjWec2b6R0mOyPaz7xtfQ&r=bMTgx2X48QVX > > yXOEL8 > > > > ALyI4dsWoR-m74c5n3d- > > ruJI8&m=eNuzGYhB7u2Wzru3VeBTY7QDZSSb9VQ9eQXW56D4 > > > > 64Y&s=eatY5xyw-474yS0cBJXyG7gLyPXFo243P2LmBDDsXd8&e= > > > > > > I agree it's good to have an API for such thing. > > > > > > So far such feature is supported in drivers on Linux, requiring only > > > Linux headers to be installed. > > > Do we need more? > > > > > > > > > > +1 to make it generic, no question here. > > > > On linux, the dependency is already there (either from linux headers > > or > > pciutils) to have the original. So including this header in DPDK is > > only useful for other OSes. > > > > I think right now we should only add pci_find_next_ext_capability() > > full implementation within linux part of PCI bus, other systems being > stubs. > > > > We can go with your suggestion Jerin about adding only the specific > > symbols needed, prefixed with RTE_, once we decide to have windows > support. > > Question is whether we need it right now. Is there a driver that would > > make use of it support more than linux currently? > > > > -- > > I don't know if there are any drivers which will require this other than linux > as of today - > > My only motivation of adding these symbols in dpdk via rte_pci_regs.h (new > file in lib/librte_pci/) was to avoid any dependency of dpdk on > /usr/include/../pci_regs.h, since I was little unsure whether in all > distributions (linux/windows) supported will have the required PCI defines > available in /usr/include/../pci_regs.h file or not in order to implement > rte_pci_find_next_ext_capability(). (unless user to bound for updating > headers by mean of installing any latest _pciutils_/packages). Moreover, for > not just this API, but if going forward if we have to add any new APIs which > could rely/depend on PCI defines availability under /usr/include. > > From the discussion so far - > > 1. Define the function under drivers/bus/pci/linux/pci.c only and add > empty/stub implementation for windows/pci.c and bsd/pci.c ? > 2. Just relying on /usr/include/ is perfectly okay without adding any defines > anywhere for now ?, it will just require <linux/pci_regs.h> inclusion in > drivers/bus/pci/linux/pci.c. OR Shall I add (may be in > lib/librte_pci/rte_pci.h ?) only required PCI defines with RTE_ prefixed and > use them instead ? >
Hello Gaetan/Jerin, Could you please comment on above - what's sufficient to be incorporated in v3 for now ? I will work on the changes accordingly. Thanks, Manish
