On Mon, Mar 29, 2021 at 4:32 PM Boqun Feng <boqun.feng@xxxxxxxxx> wrote: > > Hi Arnd, > > On Sat, Mar 20, 2021 at 05:09:10PM +0100, Arnd Bergmann wrote: > > On Sat, Mar 20, 2021 at 1:54 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > I actually still have a (not really tested) patch series to clean up > > > the pci host bridge registration, and this should make this a lot easier > > > to add on top. > > > > > > I should dig that out of my backlog and post for review. > > > > I've uploaded my series to > > https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git > > pci-probe-rework-20210320 > > > > The purpose of this series is mostly to simplify what variations of > > host probe methods exist, towards using pci_host_probe() as the > > only method. It does provide some simplifications based on that > > that, including a way to universally have access to the pci_host_bridge > > pointer during the probe function. > > > > Thanks for the suggestion and code. I spend some time to catch up. Yes, > Bjorn and you are correct, the better way is having a 'domain_nr' in the > 'pci_host_bridge' and making sure every driver fill that correctly > before probe. I definitly will use this approach. > > However, I may start small: I plan to introduce 'domain_nr' and only > fill the field at probe time for PCI_DOMAINS_GENERIC=y archs, and leave > other archs and driver alone. (honestly, I was shocked by the number of > pci_scan_root_bus_bridge() and pci_host_probe() that I need to adjust if > I really want to unify the 'domain_nr' handling for every arch and > driver ;-)). This will fulfil my requirement for Hyper-V PCI controller > on ARM64. And later on, we can switch each arch to this approach one by > one and keep the rest still working. > > Thoughts? That sounds reasonable to me, yes. I would also suggest you look at my hyperv patch from the branch I mentioned [1] and try to integrate that first. I suspect this makes it easier to do the domain rework and possibly other changes on top. Arnd https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/commit/?h=pci-probe-rework-20210320&id=44db8df9d729d
