PCI: Export pcie_find_root_port

BugLink: http://bugs.launchpad.net/bugs/1650604

commit e784930b upstream.

Export pcie_find_root_port() so we can use it outside of PCIe-AER error
injection.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/pci/pcie/aer/aer_inject.c

@@ -283,20 +283,6 @@ static int pci_bus_set_aer_ops(struct pci_bus *bus)
 	return 0;
 }
 
-static struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
-{
-	while (1) {
-		if (!pci_is_pcie(dev))
-			break;
-		if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
-			return dev;
-		if (!dev->bus->self)
-			break;
-		dev = dev->bus->self;
-	}
-	return NULL;
-}
-
 static int find_aer_device_iter(struct device *device, void *data)
 {
 	struct pcie_device **result = data;

include/linux/pci.h

@@ -1806,6 +1806,20 @@ static inline int pci_pcie_type(const struct pci_dev *dev)
 	return (pcie_caps_reg(dev) & PCI_EXP_FLAGS_TYPE) >> 4;
 }
 
+static inline struct pci_dev *pcie_find_root_port(struct pci_dev *dev)
+{
+	while (1) {
+		if (!pci_is_pcie(dev))
+			break;
+		if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
+			return dev;
+		if (!dev->bus->self)
+			break;
+		dev = dev->bus->self;
+	}
+	return NULL;
+}
+
 void pci_request_acs(void);
 bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags);
 bool pci_acs_path_enabled(struct pci_dev *start,