add glue for network interfaces to be found by fdt/ofw node or phandle.

if we're going to support switch chips (eg, marvell link street
switches as found on a3700 boards like the espressobin), then the
device tree for switch ports identifies which network interface
they're connected by by a reference (phandle) across the device
tree. this lets network drivers register the ifnet struct with the
associated node and phandle so the switch can find it and configure
it for use with the switch.

ok kettenis@

2 files changed, 59 insertions, 2 deletions

diff --git a/sys/dev/ofw/ofw_misc.c b/sys/dev/ofw/ofw_misc.c
index f4c80f10981..2e42efc0686 100644
--- a/sys/dev/ofw/ofw_misc.c
+++ b/sys/dev/ofw/ofw_misc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.c,v 1.38 2022/12/17 11:54:32 kettenis Exp $	*/
+/*	$OpenBSD: ofw_misc.c,v 1.39 2023/04/03 01:30:32 dlg Exp $	*/
 /*
  * Copyright (c) 2017-2021 Mark Kettenis
  *
@@ -119,6 +119,46 @@ regmap_read_4(struct regmap *rm, bus_size_t offset)
 	return bus_space_read_4(rm->rm_tag, rm->rm_handle, offset);
 }
 
+/*
+ * Network interface support.
+ */
+
+LIST_HEAD(, if_device) if_devices =
+	LIST_HEAD_INITIALIZER(if_devices);
+
+void
+if_register(struct if_device *ifd)
+{
+	ifd->if_phandle = OF_getpropint(ifd->if_node, "phandle", 0);
+
+	LIST_INSERT_HEAD(&if_devices, ifd, if_list);
+}
+
+struct ifnet *
+if_bynode(int node)
+{
+	struct if_device *ifd;
+
+	LIST_FOREACH(ifd, &if_devices, if_list) {
+		if (ifd->if_node == node)
+			return (ifd->if_ifp);
+	}
+
+	return (NULL);
+}
+
+struct ifnet *
+if_byphandle(uint32_t phandle)
+{
+	struct if_device *ifd;
+
+	LIST_FOREACH(ifd, &if_devices, if_list) {
+		if (ifd->if_phandle == phandle)
+			return (ifd->if_ifp);
+	}
+
+	return (NULL);
+}
 
 /*
  * PHY support.
diff --git a/sys/dev/ofw/ofw_misc.h b/sys/dev/ofw/ofw_misc.h
index efb0d3ad58f..43847cf1f7a 100644
--- a/sys/dev/ofw/ofw_misc.h
+++ b/sys/dev/ofw/ofw_misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.h,v 1.27 2022/12/12 19:18:25 kettenis Exp $	*/
+/*	$OpenBSD: ofw_misc.h,v 1.28 2023/04/03 01:30:33 dlg Exp $	*/
 /*
  * Copyright (c) 2017-2021 Mark Kettenis
  *
@@ -30,6 +30,23 @@ struct regmap *regmap_byphandle(uint32_t);
 uint32_t regmap_read_4(struct regmap *, bus_size_t);
 void	regmap_write_4(struct regmap *, bus_size_t, uint32_t);
 
+/* Interface support */
+
+struct ifnet;
+
+struct if_device {
+	int		 if_node;
+	struct ifnet	*if_ifp;
+
+	LIST_ENTRY(if_device) if_list;
+	uint32_t	 if_phandle;
+};
+
+void	if_register(struct if_device *);
+
+struct ifnet *if_bynode(int);
+struct ifnet *if_byphandle(uint32_t);
+
 /* PHY support */
 
 #define PHY_NONE	0