net: dsa: export the dsa_port_is_{user,cpu,dsa} helpers

The difference between dsa_is_user_port and dsa_port_is_user is that the
former needs to look up the list of ports of the DSA switch tree in
order to find the struct dsa_port, while the latter directly receives it
as an argument.

dsa_is_user_port is already in widespread use and has its place, so
there isn't any chance of converting all callers to a single form.
But being able to do:
	dsa_port_is_user(dp)
instead of
	dsa_is_user_port(dp->ds, dp->index)

is much more efficient too, especially when the "dp" comes from an
iterator over the DSA switch tree - this reduces the complexity from
quadratic to linear.

Move these helpers from dsa2.c to include/net/dsa.h so that others can
use them too.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -409,6 +409,21 @@ static inline struct dsa_port *dsa_to_port(struct dsa_switch *ds, int p)
 	return NULL;
 }
 
+static inline bool dsa_port_is_dsa(struct dsa_port *port)
+{
+	return port->type == DSA_PORT_TYPE_DSA;
+}
+
+static inline bool dsa_port_is_cpu(struct dsa_port *port)
+{
+	return port->type == DSA_PORT_TYPE_CPU;
+}
+
+static inline bool dsa_port_is_user(struct dsa_port *dp)
+{
+	return dp->type == DSA_PORT_TYPE_USER;
+}
+
 static inline bool dsa_is_unused_port(struct dsa_switch *ds, int p)
 {
 	return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_UNUSED;

net/dsa/dsa2.c

@@ -219,21 +219,6 @@ static void dsa_tree_put(struct dsa_switch_tree *dst)
 		kref_put(&dst->refcount, dsa_tree_release);
 }
 
-static bool dsa_port_is_dsa(struct dsa_port *port)
-{
-	return port->type == DSA_PORT_TYPE_DSA;
-}
-
-static bool dsa_port_is_cpu(struct dsa_port *port)
-{
-	return port->type == DSA_PORT_TYPE_CPU;
-}
-
-static bool dsa_port_is_user(struct dsa_port *dp)
-{
-	return dp->type == DSA_PORT_TYPE_USER;
-}
-
 static struct dsa_port *dsa_tree_find_port_by_node(struct dsa_switch_tree *dst,
 						   struct device_node *dn)
 {