Hi Jonathan, On Mon, 11 Sep 2023 15:48:56 +0100 Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> wrote: > On Tue, 15 Aug 2023 10:19:57 -0700 > Lizhi Hou <lizhi.hou@xxxxxxx> wrote: > > > The PCI endpoint device such as Xilinx Alveo PCI card maps the register > > spaces from multiple hardware peripherals to its PCI BAR. Normally, > > the PCI core discovers devices and BARs using the PCI enumeration process. > > There is no infrastructure to discover the hardware peripherals that are > > present in a PCI device, and which can be accessed through the PCI BARs. > > > > Apparently, the device tree framework requires a device tree node for the > > PCI device. Thus, it can generate the device tree nodes for hardware > > peripherals underneath. Because PCI is self discoverable bus, there might > > not be a device tree node created for PCI devices. Furthermore, if the PCI > > device is hot pluggable, when it is plugged in, the device tree nodes for > > its parent bridges are required. Add support to generate device tree node > > for PCI bridges. > > > > Add an of_pci_make_dev_node() interface that can be used to create device > > tree node for PCI devices. > > > > Add a PCI_DYNAMIC_OF_NODES config option. When the option is turned on, > > the kernel will generate device tree nodes for PCI bridges unconditionally. > > > > Initially, add the basic properties for the dynamically generated device > > tree nodes which include #address-cells, #size-cells, device_type, > > compatible, ranges, reg. > > > > Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > > Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxx> > > I tried to bring this up for a custom PCIe card emulated in QEMU on an ARM ACPI > machine. > > There are some missing parts that were present in Clements series, but not this > one, particularly creation of the root pci object. > > Anyhow, hit an intermittent crash... I am facing the same issues. I use a custom PCIe board too but on x86 ACPI machine. In order to have a working system, I need also to build a DT node for the PCI Host bridge (previously done by Clement's patch) and I am a bit stuck with interrupts. On your side (ACPI machine) how do you handle this ? I mean is your PCI host bridge provided by ACPI ? And if so, you probably need to build a DT node for this PCI host bridge and add some interrupt-map, interrupt-map-mask properties in the DT node. Best regards, Hervé -- Hervé Codina, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
