Allow child classes of simplebus to call attach directly

Reduce code duplication when a bus is subclassed from simplebus by allowing
them to call simplebus_attach directly. This is useful when the child bus
will just implement the same calls.

As not all children will expect to have a ranges property, e.g. the
Raspberry Pi firmware, allow this property to be missing.

Reviewed by:	manu
Sponsored by:	Innovate UK
Differential Revision:	https://reviews.freebsd.org/D25925

2 files changed, 8 insertions, 3 deletions

diff --git a/sys/dev/fdt/simplebus.c b/sys/dev/fdt/simplebus.c
index 2f4fa8608626..60387a9e7a81 100644
--- a/sys/dev/fdt/simplebus.c
+++ b/sys/dev/fdt/simplebus.c
@@ -46,7 +46,6 @@ __FBSDID("$FreeBSD$");
  * Bus interface.
  */
 static int		simplebus_probe(device_t dev);
-static int		simplebus_attach(device_t dev);
 static struct resource *simplebus_alloc_resource(device_t, device_t, int,
     int *, rman_res_t, rman_res_t, rman_res_t, u_int);
 static void		simplebus_probe_nomatch(device_t bus, device_t child);
@@ -134,7 +133,7 @@ simplebus_probe(device_t dev)
 	return (BUS_PROBE_GENERIC);
 }
 
-static int
+int
 simplebus_attach(device_t dev)
 {
 	struct		simplebus_softc *sc;
@@ -142,7 +141,8 @@ simplebus_attach(device_t dev)
 
 	sc = device_get_softc(dev);
 	simplebus_init(dev, 0);
-	if (simplebus_fill_ranges(sc->node, sc) < 0) {
+	if ((sc->flags & SB_FLAG_NO_RANGES) == 0 &&
+	    simplebus_fill_ranges(sc->node, sc) < 0) {
 		device_printf(dev, "could not get ranges\n");
 		return (ENXIO);
 	}
diff --git a/sys/dev/fdt/simplebus.h b/sys/dev/fdt/simplebus.h
index bc695578e874..b416f1b94cfb 100644
--- a/sys/dev/fdt/simplebus.h
+++ b/sys/dev/fdt/simplebus.h
@@ -47,6 +47,8 @@ struct simplebus_softc {
 
 	struct simplebus_range *ranges;
 	int nranges;
+#define	SB_FLAG_NO_RANGES	(1 << 0) /* Bus doesn't have ranges property */
+	int flags;
 
 	pcell_t acells, scells;
 };
@@ -63,4 +65,7 @@ struct simplebus_devinfo *simplebus_setup_dinfo(device_t dev, phandle_t node,
     struct simplebus_devinfo *di);
 int simplebus_fill_ranges(phandle_t node,
     struct simplebus_softc *sc);
+
+int simplebus_attach(device_t dev);
+
 #endif	/* _FDT_SIMPLEBUS_H */