On Fri, Aug 31, 2018 at 7:50 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Thu, Aug 30, 2018 at 7:55 PM Sunil Kovvuri <sunil.kovvuri@xxxxxxxxx> wrote: > > On Thu, Aug 30, 2018 at 7:37 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > > On Tue, Aug 28, 2018 at 3:10 PM Sunil Kovvuri <sunil.kovvuri@xxxxxxxxx> wrote: > > > Ok, I think I understand the PF/VF distinction now. One (to me) > > > surprising aspect here is that you not just have one physical function > > > that you can use to assign resources to multiple virtual functions, > > > but also a second level of virtualization that is used to assign > > > resources to "physical functions" that are less physical than the > > > name suggests. > > > > Yes, PF is just for name sake, on-boot there is no difference between > > PFs/VFs as such. > > PF0 has privilege access to assign resources to all PFs and their VFs. > > This admin function driver loads for PF0. > > ok > > > > The part that I have not grasped yet is what the split between > > > the CGX and the AF is for, how they relate to one another, and > > > what the software abstraction for the two is going to be. > > > > In HW, CGX is a separate PCI device which handles the serdes and > > physical ethernet interface. > > Ethernet driver in drivers/net/ethernet can only communicate to > > admin function driver since they share a mailbox memory. > > So we had to bind both CGX and admin function drivers to almost work as one, > > inorder to provide relavent info to ethernet drivers. That's why we > > have many functions > > from CGX driver which AF uses. > > > > eg: Firmware gets to know about a physical interface status change, > > which CGX driver gets > > to know and it uses AF's mailbox communication to inform ethernet > > driver about the event. > > Would it make sense then to combine the CGX driver and the AF > driver into a single module? It sounds like you can never really > use one without the other anyway, and that would make it easier > to have a sensible abstraction to user space. > > Arnd Thanks for the suggestion, that does makes sense. Actually i did thought about it, but i was skeptical if it would be acceptable to make a single module out of drivers registering for two different PCI devices. Will wait for few more days for more feedback from anyone and port v2 series. Sunil.
