On Tue, Aug 26, 2025 at 08:12:53AM GMT, Rob Herring wrote: > On Tue, Aug 26, 2025 at 2:15 AM Manivannan Sadhasivam <mani@xxxxxxxxxx> wrote: > > > > On Mon, Aug 25, 2025 at 05:43:15PM GMT, Rob Herring wrote: > > > On Fri, Aug 22, 2025 at 07:57:41PM +0530, Manivannan Sadhasivam wrote: > > > > On Fri, Aug 22, 2025 at 08:51:47AM GMT, Rob Herring wrote: > > > > > On Tue, Aug 19, 2025 at 12:44:53PM +0530, Manivannan Sadhasivam wrote: > > > > > > Bus:Device:Function (BDF) numbers are used to uniquely identify a > > > > > > device/function on a PCI bus. Hence, add an API to get the BDF from the > > > > > > devicetree node of a device. > > > > > > > > > > For FDT, the bus should always be 0. It doesn't make sense for FDT. The > > > > > bus number in DT reflects how firmware configured the PCI buses, but > > > > > there's no firmware configuration of PCI for FDT. > > > > > > > > This API is targeted for DT platforms only, where it is used to uniquely > > > > identify a devfn. What should I do to make it DT specific and not FDT? > > > > > > I don't understand. There are FDT and OF (actual OpenFirmware) > > > platforms. I'm pretty sure you don't care about the latter. > > > > > > > Sorry, I mixed the terminologies. Yes, I did refer the platforms making use of > > the FDT binary and not OF platforms. > > > > In the DTS, we do use bus number to differentiate between devices, not just > > devfn. But I get your point, bus no other than 0 are not fixed and allocated by > > the OS during runtime or by the firmware. > > > > So how should we uniquely identify a PCIe node here, if not by BDF? > > By path. Which is consistent since there is also no bus num in the unit-address. > But there is no straightforward way to know the full path, isn't it? Anyway, for simplicity, I'll just use the node pointer itself to identify the node. - Mani -- மணிவண்ணன் சதாசிவம்
