From: Frank Li <Frank.Li@xxxxxxx> Endpoint ┌───────────────────────────────────────────────┐ │ pcie-ep@5f010000 │ │ ┌────────────────┐│ │ │ Endpoint ││ │ │ PCIe ││ │ │ Controller ││ │ bus@5f000000 │ ┌────────► │ ┌──────────┐ │ │ ││dynamically │ │ │ Outbound Transfer │ ││allocated │┌─────┐ │ Bus ┼─────►│ ATU ───────┘ ││PCI Addr ││ │ │ Fabric │Bus │ ││ ││ CPU ├───►│ │Addr │ ││ ││ │CPU │ │0x8000_0000 ││ │└─────┘Addr└──────────┘ │ ││ │ 0x7000_0000 └────────────────┘│ └───────────────────────────────────────────────┘ bus@5f000000 { compatible = "simple-bus"; ranges = <0x80000000 0x0 0x70000000 0x10000000>; pcie-ep@5f010000 { reg = <0x80000000 0x10000000>; reg-names ="addr_space"; ... }; ... }; In the diagram above, CPU writes data to outbound window address 0x7000_0000, and the bus fabric maps it to 0x8000_0000. The ATU uses bus address 0x8000_0000 as input address and maps to some PCI address dynamically allocated by a PCI device driver on the host side. The pcie-ep@5f010000 'reg[addr_space]' is the parent bus address of the PCIe controller input, including the ATU. Set parent_bus_offset, the offset from the CPU address to the PCIe controller input address using dw_pcie_init_parent_bus_offset(). The parent_bus_offset is not used yet, so no functional change intended. Link: https://lore.kernel.org/r/20250313-pci_fixup_addr-v11-7-01d2313502ab@xxxxxxx Signed-off-by: Frank Li <Frank.Li@xxxxxxx> [bhelgaas: commit log] Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-designware-ep.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c index 2db834345ec2..bb87d0c5c665 100644 --- a/drivers/pci/controller/dwc/pcie-designware-ep.c +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c @@ -904,6 +904,13 @@ static int dw_pcie_ep_get_resources(struct dw_pcie_ep *ep) ep->phys_base = res->start; ep->addr_size = resource_size(res); + /* + * artpec6_pcie_cpu_addr_fixup() uses ep->phys_base, so call + * dw_pcie_parent_bus_offset() after setting ep->phys_base. + */ + pci->parent_bus_offset = dw_pcie_parent_bus_offset(pci, "addr_space", + ep->phys_base); + ret = of_property_read_u8(np, "max-functions", &epc->max_functions); if (ret < 0) epc->max_functions = 1; -- 2.34.1