net: dsa: Allow compiling out legacy support

Introduce a configuration option: CONFIG_NET_DSA_LEGACY allowing to compile out
support for the old platform device and Device Tree binding registration.
Support for these configurations is scheduled to be removed in 4.17.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/dsa/Kconfig

@@ -33,7 +33,7 @@ config NET_DSA_MT7530
 
 config NET_DSA_MV88E6060
 	tristate "Marvell 88E6060 ethernet switch chip support"
-	depends on NET_DSA
+	depends on NET_DSA && NET_DSA_LEGACY
 	select NET_DSA_TAG_TRAILER
 	---help---
 	  This enables support for the Marvell 88E6060 ethernet switch

drivers/net/dsa/mv88e6xxx/chip.c

@@ -3755,6 +3755,7 @@ static enum dsa_tag_protocol mv88e6xxx_get_tag_protocol(struct dsa_switch *ds,
 	return chip->info->tag_protocol;
 }
 
+#if IS_ENABLED(CONFIG_NET_DSA_LEGACY)
 static const char *mv88e6xxx_drv_probe(struct device *dsa_dev,
 				       struct device *host_dev, int sw_addr,
 				       void **priv)
@@ -3802,6 +3803,7 @@ static const char *mv88e6xxx_drv_probe(struct device *dsa_dev,
 
 	return NULL;
 }
+#endif
 
 static int mv88e6xxx_port_mdb_prepare(struct dsa_switch *ds, int port,
 				      const struct switchdev_obj_port_mdb *mdb)
@@ -3841,7 +3843,9 @@ static int mv88e6xxx_port_mdb_del(struct dsa_switch *ds, int port,
 }
 
 static const struct dsa_switch_ops mv88e6xxx_switch_ops = {
+#if IS_ENABLED(CONFIG_NET_DSA_LEGACY)
 	.probe			= mv88e6xxx_drv_probe,
+#endif
 	.get_tag_protocol	= mv88e6xxx_get_tag_protocol,
 	.setup			= mv88e6xxx_setup,
 	.adjust_link		= mv88e6xxx_adjust_link,

include/net/dsa.h

@@ -321,12 +321,14 @@ static inline unsigned int dsa_upstream_port(struct dsa_switch *ds, int port)
 typedef int dsa_fdb_dump_cb_t(const unsigned char *addr, u16 vid,
 			      bool is_static, void *data);
 struct dsa_switch_ops {
+#if IS_ENABLED(CONFIG_NET_DSA_LEGACY)
 	/*
 	 * Legacy probing.
 	 */
 	const char	*(*probe)(struct device *dsa_dev,
 				  struct device *host_dev, int sw_addr,
 				  void **priv);
+#endif
 
 	enum dsa_tag_protocol (*get_tag_protocol)(struct dsa_switch *ds,
 						  int port);
@@ -474,11 +476,20 @@ struct dsa_switch_driver {
 	const struct dsa_switch_ops *ops;
 };
 
+#if IS_ENABLED(CONFIG_NET_DSA_LEGACY)
 /* Legacy driver registration */
 void register_switch_driver(struct dsa_switch_driver *type);
 void unregister_switch_driver(struct dsa_switch_driver *type);
 struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev);
 
+#else
+static inline void register_switch_driver(struct dsa_switch_driver *type) { }
+static inline void unregister_switch_driver(struct dsa_switch_driver *type) { }
+static inline struct mii_bus *dsa_host_dev_to_mii_bus(struct device *dev)
+{
+	return NULL;
+}
+#endif
 struct net_device *dsa_dev_to_net_device(struct device *dev);
 
 /* Keep inline for faster access in hot path */

net/dsa/Kconfig

@@ -16,6 +16,15 @@ config NET_DSA
 
 if NET_DSA
 
+config NET_DSA_LEGACY
+	bool "Support for older platform device and Device Tree registration"
+	default y
+	---help---
+	  Say Y if you want to enable support for the older platform device and
+	  deprecated Device Tree binding registration.
+
+	  This feature is scheduled for removal in 4.17.
+
 # tagging formats
 config NET_DSA_TAG_BRCM
 	bool

net/dsa/Makefile

 # SPDX-License-Identifier: GPL-2.0
 # the core
 obj-$(CONFIG_NET_DSA) += dsa_core.o
-dsa_core-y += dsa.o dsa2.o legacy.o master.o port.o slave.o switch.o
+dsa_core-y += dsa.o dsa2.o master.o port.o slave.o switch.o
+dsa_core-$(CONFIG_NET_DSA_LEGACY) += legacy.o
 
 # tagging formats
 dsa_core-$(CONFIG_NET_DSA_TAG_BRCM) += tag_brcm.o

net/dsa/dsa_priv.h

@@ -97,8 +97,17 @@ const struct dsa_device_ops *dsa_resolve_tag_protocol(int tag_protocol);
 bool dsa_schedule_work(struct work_struct *work);
 
 /* legacy.c */
+#if IS_ENABLED(CONFIG_NET_DSA_LEGACY)
 int dsa_legacy_register(void);
 void dsa_legacy_unregister(void);
+#else
+static inline int dsa_legacy_register(void)
+{
+	return -ENODEV;
+}
+
+static inline void dsa_legacy_unregister(void) { }
+#endif
 int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
 		       struct net_device *dev,
 		       const unsigned char *addr, u16 vid,

net/dsa/legacy.c

@@ -718,26 +718,6 @@ static int dsa_resume(struct device *d)
 }
 #endif
 
-/* legacy way, bypassing the bridge *****************************************/
-int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
-		       struct net_device *dev,
-		       const unsigned char *addr, u16 vid,
-		       u16 flags)
-{
-	struct dsa_port *dp = dsa_slave_to_port(dev);
-
-	return dsa_port_fdb_add(dp, addr, vid);
-}
-
-int dsa_legacy_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
-		       struct net_device *dev,
-		       const unsigned char *addr, u16 vid)
-{
-	struct dsa_port *dp = dsa_slave_to_port(dev);
-
-	return dsa_port_fdb_del(dp, addr, vid);
-}
-
 static SIMPLE_DEV_PM_OPS(dsa_pm_ops, dsa_suspend, dsa_resume);
 
 static const struct of_device_id dsa_of_match_table[] = {

net/dsa/slave.c

@@ -941,6 +941,26 @@ static const struct ethtool_ops dsa_slave_ethtool_ops = {
 	.set_rxnfc		= dsa_slave_set_rxnfc,
 };
 
+/* legacy way, bypassing the bridge *****************************************/
+int dsa_legacy_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
+		       struct net_device *dev,
+		       const unsigned char *addr, u16 vid,
+		       u16 flags)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+
+	return dsa_port_fdb_add(dp, addr, vid);
+}
+
+int dsa_legacy_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
+		       struct net_device *dev,
+		       const unsigned char *addr, u16 vid)
+{
+	struct dsa_port *dp = dsa_slave_to_port(dev);
+
+	return dsa_port_fdb_del(dp, addr, vid);
+}
+
 static const struct net_device_ops dsa_slave_netdev_ops = {
 	.ndo_open	 	= dsa_slave_open,
 	.ndo_stop		= dsa_slave_close,