From: Frank Li <Frank.Li@xxxxxxx> dw_pcie_parent_bus_offset() looks up the parent bus address of a PCI controller 'reg' property in devicetree. If implemented, .cpu_addr_fixup() is a hard-coded way to get the parent bus address corresponding to a CPU physical address. Add debug code to compare the address from .cpu_addr_fixup() with the address from devicetree. If they match, warn that .cpu_addr_fixup() is redundant and should be removed; if they differ, warn that something is wrong with the devicetree. If .cpu_addr_fixup() is not implemented, the parent bus address should be identical to the CPU physical address because we previously ignored the parent bus address from devicetree. If the devicetree has a different parent bus address, warn about it being broken. [bhelgaas: split debug to separate patch for easier future revert, commit log] Link: https://lore.kernel.org/r/20250313-pci_fixup_addr-v11-5-01d2313502ab@xxxxxxx Signed-off-by: Frank Li <Frank.Li@xxxxxxx> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> --- drivers/pci/controller/dwc/pcie-designware.c | 26 +++++++++++++++++++- drivers/pci/controller/dwc/pcie-designware.h | 13 ++++++++++ 2 files changed, 38 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 0a35e36da703..985264c88b92 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -1114,7 +1114,8 @@ resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci, struct device *dev = pci->dev; struct device_node *np = dev->of_node; int index; - u64 reg_addr; + u64 reg_addr, fixup_addr; + u64 (*fixup)(struct dw_pcie *pcie, u64 cpu_addr); /* Look up reg_name address on parent bus */ index = of_property_match_string(np, "reg-names", reg_name); @@ -1126,5 +1127,28 @@ resource_size_t dw_pcie_parent_bus_offset(struct dw_pcie *pci, of_property_read_reg(np, index, ®_addr, NULL); + fixup = pci->ops->cpu_addr_fixup; + if (fixup) { + fixup_addr = fixup(pci, cpu_phy_addr); + if (reg_addr == fixup_addr) { + dev_warn(dev, "%#010llx %s reg[%d] == %#010llx; %ps is redundant\n", + cpu_phy_addr, reg_name, index, + fixup_addr, fixup); + } else { + dev_warn(dev, "%#010llx %s reg[%d] != %#010llx fixed up addr; devicetree is broken\n", + cpu_phy_addr, reg_name, + index, fixup_addr); + reg_addr = fixup_addr; + } + } else if (!pci->use_parent_dt_ranges) { + if (reg_addr != cpu_phy_addr) { + dev_warn(dev, "devicetree has incorrect translation; please check parent \"ranges\" property. CPU physical addr %#010llx, parent bus addr %#010llx\n", + cpu_phy_addr, reg_addr); + return 0; + } + } + + dev_info(dev, "%s parent bus offset is %#010llx\n", + reg_name, cpu_phy_addr - reg_addr); return cpu_phy_addr - reg_addr; } diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 16548b01347d..f08d2852cfd5 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -465,6 +465,19 @@ struct dw_pcie { struct reset_control_bulk_data core_rsts[DW_PCIE_NUM_CORE_RSTS]; struct gpio_desc *pe_rst; bool suspended; + + /* + * If iATU input addresses are offset from CPU physical addresses, + * we previously required .cpu_addr_fixup() to convert them. We + * now rely on the devicetree instead. If .cpu_addr_fixup() + * exists, we compare its results with devicetree. + * + * If .cpu_addr_fixup() does not exist, we assume the offset is + * zero and warn if devicetree claims otherwise. If we know all + * devicetrees correctly describe the offset, set + * use_parent_dt_ranges to true to avoid this warning. + */ + bool use_parent_dt_ranges; }; #define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp) -- 2.34.1
