Index: share/man/man9/OF_device_from_xref.9
===================================================================
--- share/man/man9/OF_device_from_xref.9
+++ share/man/man9/OF_device_from_xref.9
@@ -32,12 +32,15 @@
 .Nm OF_device_from_xref ,
 .Nm OF_xref_from_device ,
 .Nm OF_device_register_xref
+.Nm OF_device_unregister_xref
 .Nd "manage mappings between xrefs and devices"
 .Sh SYNOPSIS
 .In dev/ofw/ofw_bus.h
 .In dev/ofw/ofw_bus_subr.h
 .Ft int
 .Fn OF_device_register_xref "phandle_t xref" "device_t dev"
+.Ft void
+.Fn OF_device_unregister_xref "phandle_t xref" "device_t dev"
 .Ft device_t
 .Fn OF_device_from_xref "phandle_t xref"
 .Ft phandle_t
@@ -60,6 +63,15 @@
 already exists, it is replaced with the new one.
 The function always returns 0.
 .Pp
+.Fn OF_device_unregister_xref
+removes a map entry from the effective phandle
+.Fa xref
+to device
+.Fa dev .
+If a mapping entry for
+.Fa xref
+does not exists, it silently returns.
+.Pp
 .Fn OF_device_from_xref
 returns a device_t instance associated with the effective phandle
 .Fa xref .
Index: sys/dev/ofw/openfirm.h
===================================================================
--- sys/dev/ofw/openfirm.h
+++ sys/dev/ofw/openfirm.h
@@ -151,6 +151,7 @@
 device_t	OF_device_from_xref(phandle_t xref);
 phandle_t	OF_xref_from_device(device_t dev);
 int		OF_device_register_xref(phandle_t xref, device_t dev);
+void		OF_device_unregister_xref(phandle_t xref, device_t dev);
 
 /* Device I/O functions */
 ihandle_t	OF_open(const char *path);
Index: sys/dev/ofw/openfirm.c
===================================================================
--- sys/dev/ofw/openfirm.c
+++ sys/dev/ofw/openfirm.c
@@ -189,6 +189,15 @@
 	return (xi);
 }
 
+static void
+xrefinfo_remove(struct xrefinfo *xi)
+{
+
+	mtx_lock(&xreflist_lock);
+	SLIST_REMOVE(&xreflist, xi, xrefinfo, next_entry);
+	mtx_unlock(&xreflist_lock);
+}
+
 /*
  * OFW install routines.  Highest priority wins, equal priority also
  * overrides allowing last-set to win.
@@ -706,6 +715,16 @@
 	panic("Attempt to register device before xreflist_init");
 }
 
+void
+OF_device_unregister_xref(phandle_t xref, device_t dev)
+{
+	struct xrefinfo *xi;
+
+	if ((xi = xrefinfo_find(xref, FIND_BY_XREF)) == NULL)
+		return;
+	xrefinfo_remove(xi);
+}
+
 /*  Call the method in the scope of a given instance. */
 int
 OF_call_method(const char *method, ihandle_t instance, int nargs, int nreturns,