diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 8dd38e69d6f2a8ae4f4b7d6801f3f321abb5ac1a..4dbf9f96ae5ba31d761b30ee43c11d2f053140fe 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -3,6 +3,8 @@
 
 #define PCI_FIND_CAP_TTL	48
 
+#define PCI_VSEC_ID_INTEL_TBT	0x1234	/* Thunderbolt */
+
 extern const unsigned char pcie_link_speed[];
 
 bool pcie_cap_has_lnkctl(const struct pci_dev *dev);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index dfc9a27941418976c0fadee7e6628531fbb47613..90592d424e9b67458ad740ddb3b09d50f5ec30ff 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1208,6 +1208,24 @@ void set_pcie_hotplug_bridge(struct pci_dev *pdev)
 		pdev->is_hotplug_bridge = 1;
 }
 
+static void set_pcie_thunderbolt(struct pci_dev *dev)
+{
+	int vsec = 0;
+	u32 header;
+
+	while ((vsec = pci_find_next_ext_capability(dev, vsec,
+						    PCI_EXT_CAP_ID_VNDR))) {
+		pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header);
+
+		/* Is the device part of a Thunderbolt controller? */
+		if (dev->vendor == PCI_VENDOR_ID_INTEL &&
+		    PCI_VNDR_HEADER_ID(header) == PCI_VSEC_ID_INTEL_TBT) {
+			dev->is_thunderbolt = 1;
+			return;
+		}
+	}
+}
+
 /**
  * pci_ext_cfg_is_aliased - is ext config space just an alias of std config?
  * @dev: PCI device
@@ -1360,6 +1378,9 @@ int pci_setup_device(struct pci_dev *dev)
 	/* need to have dev->class ready */
 	dev->cfg_size = pci_cfg_space_size(dev);
 
+	/* need to have dev->cfg_size ready */
+	set_pcie_thunderbolt(dev);
+
 	/* "Unknown power state" */
 	dev->current_state = PCI_UNKNOWN;
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index eb3da1a04e6cdc7d3f4efab5532f53abcdf3a28f..5948cfdc984e2f849507fa1d0fb8f2bed3c01cfa 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -358,6 +358,7 @@ struct pci_dev {
 	unsigned int	is_virtfn:1;
 	unsigned int	reset_fn:1;
 	unsigned int    is_hotplug_bridge:1;
+	unsigned int	is_thunderbolt:1; /* Thunderbolt controller */
 	unsigned int    __aer_firmware_first_valid:1;
 	unsigned int	__aer_firmware_first:1;
 	unsigned int	broken_intx_masking:1;
@@ -2160,6 +2161,28 @@ static inline bool pci_ari_enabled(struct pci_bus *bus)
 	return bus->self && bus->self->ari_enabled;
 }
 
+/**
+ * pci_is_thunderbolt_attached - whether device is on a Thunderbolt daisy chain
+ * @pdev: PCI device to check
+ *
+ * Walk upwards from @pdev and check for each encountered bridge if it's part
+ * of a Thunderbolt controller.  Reaching the host bridge means @pdev is not
+ * Thunderbolt-attached.  (But rather soldered to the mainboard usually.)
+ */
+static inline bool pci_is_thunderbolt_attached(struct pci_dev *pdev)
+{
+	struct pci_dev *parent = pdev;
+
+	if (pdev->is_thunderbolt)
+		return true;
+
+	while ((parent = pci_upstream_bridge(parent)))
+		if (parent->is_thunderbolt)
+			return true;
+
+	return false;
+}
+
 /* provide the legacy pci_dma_* API */
 #include <linux/pci-dma-compat.h>