net: dsa: add dsa_is_normal_port helper

Introduce a dsa_is_normal_port helper to check if a given port is a
normal user port as opposed to a CPU port or DSA link.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -248,6 +248,11 @@ static inline bool dsa_is_dsa_port(struct dsa_switch *ds, int p)
 	return !!((ds->dsa_port_mask) & (1 << p));
 }
 
+static inline bool dsa_is_normal_port(struct dsa_switch *ds, int p)
+{
+	return !dsa_is_cpu_port(ds, p) && !dsa_is_dsa_port(ds, p);
+}
+
 static inline bool dsa_is_port_initialized(struct dsa_switch *ds, int p)
 {
 	return ds->enabled_port_mask & (1 << p) && ds->ports[p].netdev;