diff --git a/include/linux/pci.h b/include/linux/pci.h
index 61978a4608412896a3f199024c9c7b7d349c152d..92c131efec1c3631d7af64e04008df13da6dbe33 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1839,4 +1839,17 @@ int pci_for_each_dma_alias(struct pci_dev *pdev,
  */
 struct pci_dev *pci_find_upstream_pcie_bridge(struct pci_dev *pdev);
 
+/* helper functions for operation of device flag */
+static inline void pci_set_dev_assigned(struct pci_dev *pdev)
+{
+	pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+}
+static inline void pci_clear_dev_assigned(struct pci_dev *pdev)
+{
+	pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+}
+static inline bool pci_is_dev_assigned(struct pci_dev *pdev)
+{
+	return (pdev->dev_flags & PCI_DEV_FLAGS_ASSIGNED) == PCI_DEV_FLAGS_ASSIGNED;
+}
 #endif /* LINUX_PCI_H */