diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c index 55c4b07ec1f6..0c316bae1726 100644 --- a/arch/x86/pci/acpi.c +++ b/arch/x86/pci/acpi.c @@ -250,6 +250,125 @@ void __init pci_acpi_crs_quirks(void) pr_info("Please notify linux-pci@vger.kernel.org so future kernels can do this automatically\n"); } +/* + * Check if pdev is part of a PCIe switch that is directly below the + * specified bridge. + */ +static bool pcie_switch_directly_under(struct pci_dev *bridge, + struct pci_dev *pdev) +{ + struct pci_dev *parent = pci_upstream_bridge(pdev); + + /* If the device doesn't have a parent, it's not under anything */ + if (!parent) + return false; + + /* + * If the device has a PCIe type, check if it is below the + * corresponding PCIe switch components (if applicable). Then check + * if its upstream port is directly beneath the specified bridge. + */ + switch (pci_pcie_type(pdev)) { + case PCI_EXP_TYPE_UPSTREAM: + return parent == bridge; + + case PCI_EXP_TYPE_DOWNSTREAM: + if (pci_pcie_type(parent) != PCI_EXP_TYPE_UPSTREAM) + return false; + parent = pci_upstream_bridge(parent); + return parent == bridge; + + case PCI_EXP_TYPE_ENDPOINT: + if (pci_pcie_type(parent) != PCI_EXP_TYPE_DOWNSTREAM) + return false; + parent = pci_upstream_bridge(parent); + if (!parent || pci_pcie_type(parent) != PCI_EXP_TYPE_UPSTREAM) + return false; + parent = pci_upstream_bridge(parent); + return parent == bridge; + } + + return false; +} + +static bool pcie_has_usb4_host_interface(struct pci_dev *pdev) +{ + struct fwnode_handle *fwnode; + + /* + * For USB4, the tunneled PCIe Root or Downstream Ports are marked + * with the "usb4-host-interface" ACPI property, so we look for + * that first. This should cover most cases. + */ + fwnode = fwnode_find_reference(dev_fwnode(&pdev->dev), + "usb4-host-interface", 0); + if (!IS_ERR(fwnode)) { + fwnode_handle_put(fwnode); + return true; + } + + /* + * Any integrated Thunderbolt 3/4 PCIe Root Ports from Intel + * before Alder Lake do not have the "usb4-host-interface" + * property so we use their PCI IDs instead. All these are + * tunneled. This list is not expected to grow. + */ + if (pdev->vendor == PCI_VENDOR_ID_INTEL) { + switch (pdev->device) { + /* Ice Lake Thunderbolt 3 PCIe Root Ports */ + case 0x8a1d: + case 0x8a1f: + case 0x8a21: + case 0x8a23: + /* Tiger Lake-LP Thunderbolt 4 PCIe Root Ports */ + case 0x9a23: + case 0x9a25: + case 0x9a27: + case 0x9a29: + /* Tiger Lake-H Thunderbolt 4 PCIe Root Ports */ + case 0x9a2b: + case 0x9a2d: + case 0x9a2f: + case 0x9a31: + return true; + } + } + + return false; +} + +bool arch_pci_dev_is_removable(struct pci_dev *pdev) +{ + struct pci_dev *parent, *root; + + /* pdev without a parent or Root Port is never tunneled */ + parent = pci_upstream_bridge(pdev); + if (!parent) + return false; + root = pcie_find_root_port(pdev); + if (!root) + return false; + + /* Internal PCIe devices are not tunneled */ + if (!root->external_facing) + return false; + + /* Anything directly behind a "usb4-host-interface" is tunneled */ + if (pcie_has_usb4_host_interface(parent)) + return true; + + /* + * Check if this is a discrete Thunderbolt/USB4 controller that is + * directly behind the non-USB4 PCIe Root Port marked as + * "ExternalFacingPort". Those are not behind a PCIe tunnel. + */ + if (pcie_switch_directly_under(root, pdev)) + return false; + + /* PCIe devices after the discrete chip are tunneled */ + return true; +} + #ifdef CONFIG_PCI_MMCONFIG static int check_segment(u16 seg, struct device *dev, char *estr) { diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 9b2aa4ef3192..8a7e58e20839 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1635,23 +1635,33 @@ static void set_pcie_thunderbolt(struct pci_dev *dev) static void set_pcie_untrusted(struct pci_dev *dev) { - struct pci_dev *parent; + struct pci_dev *parent = pci_upstream_bridge(dev); + if (!parent) + return; /* - * If the upstream bridge is untrusted we treat this device + * If the upstream bridge is untrusted we treat this device as * untrusted as well. */ - parent = pci_upstream_bridge(dev); - if (parent && (parent->untrusted || parent->external_facing)) + if (parent->untrusted) { dev->untrusted = true; + return; + } + + if (arch_pci_dev_is_removable(dev)) { + pci_dbg(dev, "marking as untrusted\n"); + dev->untrusted = true; + } } static void pci_set_removable(struct pci_dev *dev) { struct pci_dev *parent = pci_upstream_bridge(dev); + if (!parent) + return; /* - * We (only) consider everything downstream from an external_facing + * We (only) consider everything tunneled below an external_facing * device to be removable by the user. We're mainly concerned with * consumer platforms with user accessible thunderbolt ports that are * vulnerable to DMA attacks, and we expect those ports to be marked by @@ -1661,9 +1671,15 @@ static void pci_set_removable(struct pci_dev *dev) * accessible to user / may not be removed by end user, and thus not * exposed as "removable" to userspace. */ - if (parent && - (parent->external_facing || dev_is_removable(&parent->dev))) + if (dev_is_removable(&parent->dev)) { dev_set_removable(&dev->dev, DEVICE_REMOVABLE); + return; + } + + if (arch_pci_dev_is_removable(dev)) { + pci_dbg(dev, "marking as removable\n"); + dev_set_removable(&dev->dev, DEVICE_REMOVABLE); + } } /** diff --git a/include/linux/pci.h b/include/linux/pci.h index e41032dd12a5..5db9b0b2dca1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -2606,6 +2606,12 @@ pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; } static inline bool pci_pr3_present(struct pci_dev *pdev) { return false; } #endif +#if defined(CONFIG_X86) && defined(CONFIG_ACPI) +bool arch_pci_dev_is_removable(struct pci_dev *pdev); +#else +static inline bool arch_pci_dev_is_removable(struct pci_dev *pdev) { return false; } +#endif + #ifdef CONFIG_EEH static inline struct eeh_dev *pci_dev_to_eeh_dev(struct pci_dev *pdev) {