[PATCH net-next 2/4] net: dsa: Add wrappers for overloaded ndo_ops

[Florian Fainelli <f.fainelli@gmail.com>]

Add definitions for the dsa_netdevice_ops structure which is a subset of
the net_device_ops structure for the specific operations that we care
about overlaying on top of the DSA CPU port net_device and provide
inline stubs that take core managing whether DSA code is reachable.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 include/net/dsa.h | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 6fa418ff1175..681ba2752514 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -86,6 +86,18 @@ struct dsa_device_ops {
 	enum dsa_tag_protocol proto;
 };
 
+/* This structure defines the control interfaces that are overlayed by the
+ * DSA layer on top of the DSA CPU/management net_device instance. This is
+ * used by the core net_device layer while calling various net_device_ops
+ * function pointers.
+ */
+struct dsa_netdevice_ops {
+	int (*ndo_do_ioctl)(struct net_device *dev, struct ifreq *ifr,
+			    int cmd);
+	int (*ndo_get_phys_port_name)(struct net_device *dev, char *name,
+				      size_t len);
+};
+
 #define DSA_TAG_DRIVER_ALIAS "dsa_tag-"
 #define MODULE_ALIAS_DSA_TAG_DRIVER(__proto)				\
 	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __stringify(__proto##_VALUE))
@@ -217,6 +229,7 @@ struct dsa_port {
 	/*
 	 * Original copy of the master netdev net_device_ops
 	 */
+	const struct dsa_netdevice_ops *netdev_ops;
 	const struct net_device_ops *orig_ndo_ops;
 
 	bool setup;
@@ -679,6 +692,34 @@ static inline bool dsa_can_decode(const struct sk_buff *skb,
 	return false;
 }
 
+#if IS_ENABLED(CONFIG_NET_DSA)
+#define dsa_build_ndo_op(name, arg1_type, arg1_name, arg2_type, arg2_name) \
+static int inline dsa_##name(struct net_device *dev, arg1_type arg1_name, \
+			     arg2_type arg2_name)	\
+{							\
+	const struct dsa_netdevice_ops *ops;		\
+	int err = -EOPNOTSUPP;				\
+							\
+	if (!dev->dsa_ptr)				\
+		return err;				\
+							\
+	ops = dev->dsa_ptr->netdev_ops;			\
+	if (!ops || !ops->name)				\
+		return err;				\
+							\
+	return ops->name(dev, arg1_name, arg2_name);	\
+}
+#else
+#define dsa_build_ndo_op(name, ...)			\
+static inline int dsa_##name(struct net_device *dev, ...) \
+{							\
+	return -EOPNOTSUPP;				\
+}
+#endif
+
+dsa_build_ndo_op(ndo_do_ioctl, struct ifreq *, ifr, int, cmd);
+dsa_build_ndo_op(ndo_get_phys_port_name, char *, name, size_t, len);
+
 void dsa_unregister_switch(struct dsa_switch *ds);
 int dsa_register_switch(struct dsa_switch *ds);
 struct dsa_switch *dsa_switch_find(int tree_index, int sw_index);
-- 
2.25.1