dsa: Add boilerplate helper to register DSA tag driver modules

A DSA tag driver module will need to register the tag protocols it
implements with the DSA core. Add macros containing this boiler plate.

The registration/unregistration code is currently just a stub. A Later
patch will add the real implementation.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

v2
Fix indent of #endif
Rewrite to move list pointer into a new structure
v3
Move kdoc next to macro
Fix THIS_MODULE indentation

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 66 insertions, 0 deletions

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 720036f48fb3..08ac05c014e3 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -594,4 +594,70 @@ int dsa_port_get_ethtool_phy_stats(struct dsa_port *dp, uint64_t *data);
 int dsa_port_get_phy_sset_count(struct dsa_port *dp);
 void dsa_port_phylink_mac_change(struct dsa_switch *ds, int port, bool up);
 
+struct dsa_tag_driver {
+	const struct dsa_device_ops *ops;
+	struct list_head list;
+	struct module *owner;
+};
+
+void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
+			      unsigned int count,
+			      struct module *owner);
+void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
+				unsigned int count);
+
+#define dsa_tag_driver_module_drivers(__dsa_tag_drivers_array, __count)	\
+static int __init dsa_tag_driver_module_init(void)			\
+{									\
+	dsa_tag_drivers_register(__dsa_tag_drivers_array, __count,	\
+				 THIS_MODULE);				\
+	return 0;							\
+}									\
+module_init(dsa_tag_driver_module_init);				\
+									\
+static void __exit dsa_tag_driver_module_exit(void)			\
+{									\
+	dsa_tag_drivers_unregister(__dsa_tag_drivers_array, __count);	\
+}									\
+module_exit(dsa_tag_driver_module_exit)
+
+/**
+ * module_dsa_tag_drivers() - Helper macro for registering DSA tag
+ * drivers
+ * @__ops_array: Array of tag driver strucutres
+ *
+ * Helper macro for DSA tag drivers which do not do anything special
+ * in module init/exit. Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit().
+ */
+#define module_dsa_tag_drivers(__ops_array)				\
+dsa_tag_driver_module_drivers(__ops_array, ARRAY_SIZE(__ops_array))
+
+#define DSA_TAG_DRIVER_NAME(__ops) dsa_tag_driver ## _ ## __ops
+
+/* Create a static structure we can build a linked list of dsa_tag
+ * drivers
+ */
+#define DSA_TAG_DRIVER(__ops)						\
+static struct dsa_tag_driver DSA_TAG_DRIVER_NAME(__ops) = {		\
+	.ops = &__ops,							\
+}
+
+/**
+ * module_dsa_tag_driver() - Helper macro for registering a single DSA tag
+ * driver
+ * @__ops: Single tag driver structures
+ *
+ * Helper macro for DSA tag drivers which do not do anything special
+ * in module init/exit. Each module may only use this macro once, and
+ * calling it replaces module_init() and module_exit().
+ */
+#define module_dsa_tag_driver(__ops)					\
+DSA_TAG_DRIVER(__ops);							\
+									\
+static struct dsa_tag_driver *dsa_tag_driver_array[] =	{		\
+	&DSA_TAG_DRIVER_NAME(__ops)					\
+};									\
+module_dsa_tag_drivers(dsa_tag_driver_array)
 #endif
+