From 9850907ee1dd4376c09c4129e0adbe3b39d191b7 Mon Sep 17 00:00:00 2001 From: Semih Baskan Date: Tue, 13 Oct 2026 17:04:21 -0500 Subject: PCI: iproc: Use the EROM outbound window on BCMA The PCIe outbound window base on Northstar depends on the PCIe Gen2 core revision. Revision 0x01 uses 0x08000000, 0x40000000 and 0x48000000 for controllers 0 to 2, while revision 0x07 (NS-B0) uses 0x08000000, 0x20000000 and 0x28000000. Broadcom's own driver branches on the core revision for exactly this reason. bcm-ns.dtsi is shared by every Northstar SoC, so it cannot carry a value that is correct on both. Commit 767012397976 ("ARM: dts: BCM5301X: Describe PCIe controllers fully") gave the controllers a ranges property. The commit shipped in v7.1. With that property present, two things go wrong with this driver: 1) devm_pci_alloc_host_bridge() parses those ranges and requests them, then this driver adds its own window and requests the whole list a second time, so every controller fails to probe with -EBUSY. 2) The DT window itself is only correct on core revision 0x07. On revision 0x01 it points at an address the hardware does not decode, and the first MMIO access to a BAR takes an imprecise external abort. The enumeration ROM reports the correct base for the revision actually present, and bcma already provides it as addr_s[0]. To solve 1), use pci_alloc_host_bridge() directly to avoid the request of all the DT resources done in pci_parse_request_of_pci_ranges(). Instead, request the memory window from the EROM. To solve 2), parse the memory resources from DT and emit a warning if it describes a window that doesn't match the window from the EROM. The mismatch means the devicetree describes a window the hardware does not decode, and that should be fixed in the dts rather than ignored silently. The driver is correct whether or not the DT describes a window. The same commit also added compatible = "brcm,iproc-pcie", so these nodes now match pcie-iproc-platform. With CONFIG_PCIE_IPROC_PLATFORM enabled, which is the default on ARCH_BCM_IPROC, that driver binds them first and this driver's probe fails inside devm_pci_alloc_host_bridge(). This commit fixes the configurations where the BCMA driver is the one in use; OpenWrt builds that way, with PCIE_IPROC_PLATFORM disabled. The platform path takes the DT window as-is and has the same wrong address on core revision 0x01, so that side needs a devicetree fix either way. Based on: https://patch.msgid.link/20260807160526.379-1-strst.gs@gmail.com https://patch.msgid.link/20260912043626.437-1-strst.gs@gmail.com Fixes: 767012397976 ("ARM: dts: BCM5301X: Describe PCIe controllers fully") Signed-off-by: Semih Baskan Signed-off-by: Manivannan Sadhasivam Signed-off-by: Bjorn Helgaas Tested-by: Semih Baskan Link: https://patch.msgid.link/20261013220421.1588051-3-bhelgaas@google.com --- drivers/pci/controller/pcie-iproc-bcma.c | 40 +++++++++++++++++++++++++++++--- 1 file changed, 37 insertions(+), 3 deletions(-) (limited to 'drivers/pci/controller') diff --git a/drivers/pci/controller/pcie-iproc-bcma.c b/drivers/pci/controller/pcie-iproc-bcma.c index 593418c2bc3a..1e258cd8fed4 100644 --- a/drivers/pci/controller/pcie-iproc-bcma.c +++ b/drivers/pci/controller/pcie-iproc-bcma.c @@ -11,7 +11,9 @@ #include #include #include +#include +#include "../pci.h" #include "pcie-iproc.h" @@ -31,6 +33,29 @@ static int iproc_bcma_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) return bcma_core_irq(bdev, 5); } +static void iproc_bcma_pcie_check_dt_window(struct iproc_pcie *pcie) +{ + struct device_node *np = pcie->dev->of_node; + struct of_pci_range_parser parser; + struct of_pci_range range; + struct resource res; + + if (!np || of_pci_range_parser_init(&parser, np)) + return; + + for_each_of_pci_range(&parser, &range) { + if ((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) + continue; + + if (of_pci_range_to_resource(&range, np, &res)) + continue; + + if (res.start != pcie->mem.start || res.end != pcie->mem.end) + dev_warn(pcie->dev, "DT window %pR does not match EROM window %pR, using EROM\n", + &res, &pcie->mem); + } +} + static int iproc_bcma_pcie_probe(struct bcma_device *bdev) { struct device *dev = &bdev->dev; @@ -38,10 +63,20 @@ static int iproc_bcma_pcie_probe(struct bcma_device *bdev) struct pci_host_bridge *bridge; int ret; - bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie)); + bridge = pci_alloc_host_bridge(sizeof(*pcie)); if (!bridge) return -ENOMEM; + bridge->dev.parent = dev; + + ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release, + bridge); + if (ret) + return -ENOMEM; + + bridge->swizzle_irq = pci_common_swizzle; + bridge->map_irq = iproc_bcma_pcie_map_irq; + pcie = pci_host_bridge_priv(bridge); pcie->dev = dev; @@ -59,13 +94,12 @@ static int iproc_bcma_pcie_probe(struct bcma_device *bdev) pcie->mem.end = bdev->addr_s[0] + SZ_128M - 1; pcie->mem.name = "PCIe MEM space"; pcie->mem.flags = IORESOURCE_MEM; + iproc_bcma_pcie_check_dt_window(pcie); pci_add_resource(&bridge->windows, &pcie->mem); ret = devm_request_pci_bus_resources(dev, &bridge->windows); if (ret) return ret; - bridge->map_irq = iproc_bcma_pcie_map_irq; - bcma_set_drvdata(bdev, pcie); return iproc_pcie_setup(pcie, &bridge->windows); -- cgit v1.2.3