From 407d1a51921e9f28c1bcec647c2205925bd1fdab Mon Sep 17 00:00:00 2001 From: Lizhi Hou Date: Tue, 15 Aug 2023 10:19:57 -0700 Subject: PCI: Create device tree node for bridge 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 Signed-off-by: Lizhi Hou Link: https://lore.kernel.org/r/1692120000-46900-3-git-send-email-lizhi.hou@amd.com Signed-off-by: Rob Herring --- drivers/pci/Kconfig | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/pci/Kconfig') diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig index 3c07d8d214b3..49bd09c7dd0a 100644 --- a/drivers/pci/Kconfig +++ b/drivers/pci/Kconfig @@ -194,6 +194,18 @@ config PCI_HYPERV The PCI device frontend driver allows the kernel to import arbitrary PCI devices from a PCI backend to support PCI driver domains. +config PCI_DYNAMIC_OF_NODES + bool "Create Device tree nodes for PCI devices" + depends on OF + select OF_DYNAMIC + help + This option enables support for generating device tree nodes for some + PCI devices. Thus, the driver of this kind can load and overlay + flattened device tree for its downstream devices. + + Once this option is selected, the device tree nodes will be generated + for all PCI bridges. + choice prompt "PCI Express hierarchy optimization setting" default PCIE_BUS_DEFAULT -- cgit v1.2.3