diff --git a/src/drivers/bus/pci.c b/src/drivers/bus/pci.c
index 15d2da088..9e47dd93c 100644
--- a/src/drivers/bus/pci.c
+++ b/src/drivers/bus/pci.c
@@ -80,6 +80,20 @@ static unsigned long pci_bar ( struct pci_device *pci, unsigned int reg ) {
 	return low;
 }
 
+/**
+ * Get PCI BAR type
+ *
+ * @v pci		PCI device
+ * @v reg		PCI register number
+ * @v is_io		BAR is an I/O BAR
+ */
+int pci_bar_is_io ( struct pci_device *pci, unsigned int reg ) {
+	unsigned long bar;
+
+	bar = pci_bar ( pci, reg );
+	return ( bar & PCI_BASE_ADDRESS_SPACE_IO );
+}
+
 /**
  * Find the start of a PCI BAR
  *
diff --git a/src/include/ipxe/pci.h b/src/include/ipxe/pci.h
index 44095afe2..f65c8c296 100644
--- a/src/include/ipxe/pci.h
+++ b/src/include/ipxe/pci.h
@@ -317,6 +317,7 @@ struct pci_driver {
 	PCI_SLOT ( (pci)->busdevfn ), PCI_FUNC ( (pci)->busdevfn )
 
 extern void adjust_pci_device ( struct pci_device *pci );
+extern int pci_bar_is_io ( struct pci_device *pci, unsigned int reg );
 extern unsigned long pci_bar_start ( struct pci_device *pci,
 				     unsigned int reg );
 extern void pci_bar_set ( struct pci_device *pci, unsigned int reg,