From: Felix Fietkau <nbd@nbd.name>
Date: Mon, 7 Dec 2020 20:31:48 +0100
Subject: [PATCH] net: dsa: resolve forwarding path for dsa slave ports

Add .ndo_fill_forward_path for dsa slave port devices

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -837,6 +837,7 @@ enum net_device_path_type {
 	DEV_PATH_ETHERNET = 0,
 	DEV_PATH_VLAN,
 	DEV_PATH_BRIDGE,
+	DEV_PATH_DSA,
 };
 
 struct net_device_path {
@@ -856,6 +857,10 @@ struct net_device_path {
 			u16		vlan_id;
 			__be16		vlan_proto;
 		} bridge;
+		struct {
+			int port;
+			u16 proto;
+		} dsa;
 	};
 };
 
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1582,6 +1582,21 @@ static struct devlink_port *dsa_slave_ge
 	return dp->ds->devlink ? &dp->devlink_port : NULL;
 }
 
+static int dsa_slave_fill_forward_path(struct net_device_path_ctx *ctx,
+				       struct net_device_path *path)
+{
+	struct dsa_port *dp = dsa_slave_to_port(ctx->dev);
+	struct dsa_port *cpu_dp = dp->cpu_dp;
+
+	path->dev = ctx->dev;
+	path->type = DEV_PATH_DSA;
+	path->dsa.proto = cpu_dp->tag_ops->proto;
+	path->dsa.port = dp->index;
+	ctx->dev = cpu_dp->master;
+
+	return 0;
+}
+
 static const struct net_device_ops dsa_slave_netdev_ops = {
 	.ndo_open	 	= dsa_slave_open,
 	.ndo_stop		= dsa_slave_close,
@@ -1607,6 +1622,7 @@ static const struct net_device_ops dsa_s
 	.ndo_vlan_rx_kill_vid	= dsa_slave_vlan_rx_kill_vid,
 	.ndo_get_devlink_port	= dsa_slave_get_devlink_port,
 	.ndo_change_mtu		= dsa_slave_change_mtu,
+	.ndo_fill_forward_path	= dsa_slave_fill_forward_path,
 };
 
 static struct device_type dsa_type = {