devlink: Reduce struct devlink exposure

The declaration of struct devlink in general header provokes the
situation where internal fields can be accidentally used by the driver
authors. In order to reduce such possible situations, let's reduce the
namespace exposure of struct devlink.

Signed-off-by: Leon Romanovsky <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/mellanox/mlxfw/mlxfw.h

···
 static inline
 struct device *mlxfw_dev_dev(struct mlxfw_dev *mlxfw_dev)
 {
-	return mlxfw_dev->devlink->dev;
+	return devlink_to_dev(mlxfw_dev->devlink);
 }
 
 #define MLXFW_PRFX "mlxfw: "

include/net/devlink.h

···
 #include <linux/xarray.h>
 #include <linux/firmware.h>
 
-#define DEVLINK_RELOAD_STATS_ARRAY_SIZE \
-	(__DEVLINK_RELOAD_LIMIT_MAX * __DEVLINK_RELOAD_ACTION_MAX)
-
-struct devlink_dev_stats {
-	u32 reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
-	u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
-};
-
-struct devlink_ops;
-
-struct devlink {
-	u32 index;
-	struct list_head port_list;
-	struct list_head rate_list;
-	struct list_head sb_list;
-	struct list_head dpipe_table_list;
-	struct list_head resource_list;
-	struct list_head param_list;
-	struct list_head region_list;
-	struct list_head reporter_list;
-	struct mutex reporters_lock; /* protects reporter_list */
-	struct devlink_dpipe_headers *dpipe_headers;
-	struct list_head trap_list;
-	struct list_head trap_group_list;
-	struct list_head trap_policer_list;
-	const struct devlink_ops *ops;
-	struct xarray snapshot_ids;
-	struct devlink_dev_stats stats;
-	struct device *dev;
-	possible_net_t _net;
-	struct mutex lock; /* Serializes access to devlink instance specific objects such as
-			    * port, sb, dpipe, resource, params, region, traps and more.
-			    */
-	u8 reload_failed:1,
-	   reload_enabled:1;
-	refcount_t refcount;
-	struct completion comp;
-	char priv[0] __aligned(NETDEV_ALIGN);
-};
+struct devlink;
 
 struct devlink_port_phys_attrs {
 	u32 port_number; /* Same value as "split group".
···
 				    struct netlink_ext_ack *extack);
 };
 
-static inline void *devlink_priv(struct devlink *devlink)
-{
-	BUG_ON(!devlink);
-	return &devlink->priv;
-}
-
-static inline struct devlink *priv_to_devlink(void *priv)
-{
-	BUG_ON(!priv);
-	return container_of(priv, struct devlink, priv);
-}
+void *devlink_priv(struct devlink *devlink);
+struct devlink *priv_to_devlink(void *priv);
+struct device *devlink_to_dev(const struct devlink *devlink);
 
 static inline struct devlink_port *
 netdev_to_devlink_port(struct net_device *dev)

include/trace/events/devlink.h

···
 	TP_ARGS(devlink, incoming, type, buf, len),
 
 	TP_STRUCT__entry(
-		__string(bus_name, devlink->dev->bus->name)
-		__string(dev_name, dev_name(devlink->dev))
-		__string(driver_name, devlink->dev->driver->name)
+		__string(bus_name, devlink_to_dev(devlink)->bus->name)
+		__string(dev_name, dev_name(devlink_to_dev(devlink)))
+		__string(driver_name, devlink_to_dev(devlink)->driver->name)
 		__field(bool, incoming)
 		__field(unsigned long, type)
 		__dynamic_array(u8, buf, len)
···
 	),
 
 	TP_fast_assign(
-		__assign_str(bus_name, devlink->dev->bus->name);
-		__assign_str(dev_name, dev_name(devlink->dev));
-		__assign_str(driver_name, devlink->dev->driver->name);
+		__assign_str(bus_name, devlink_to_dev(devlink)->bus->name);
+		__assign_str(dev_name, dev_name(devlink_to_dev(devlink)));
+		__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
 		__entry->incoming = incoming;
 		__entry->type = type;
 		memcpy(__get_dynamic_array(buf), buf, len);
···
 	TP_ARGS(devlink, err, msg),
 
 	TP_STRUCT__entry(
-		__string(bus_name, devlink->dev->bus->name)
-		__string(dev_name, dev_name(devlink->dev))
-		__string(driver_name, devlink->dev->driver->name)
+		__string(bus_name, devlink_to_dev(devlink)->bus->name)
+		__string(dev_name, dev_name(devlink_to_dev(devlink)))
+		__string(driver_name, devlink_to_dev(devlink)->driver->name)
 		__field(int, err)
 		__string(msg, msg)
 		),
 
 	TP_fast_assign(
-		__assign_str(bus_name, devlink->dev->bus->name);
-		__assign_str(dev_name, dev_name(devlink->dev));
-		__assign_str(driver_name, devlink->dev->driver->name);
+		__assign_str(bus_name, devlink_to_dev(devlink)->bus->name);
+		__assign_str(dev_name, dev_name(devlink_to_dev(devlink)));
+		__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
 		__entry->err = err;
 		__assign_str(msg, msg);
 		),
···
 	TP_ARGS(devlink, reporter_name, msg),
 
 	TP_STRUCT__entry(
-		__string(bus_name, devlink->dev->bus->name)
-		__string(dev_name, dev_name(devlink->dev))
-		__string(driver_name, devlink->dev->driver->name)
+		__string(bus_name, devlink_to_dev(devlink)->bus->name)
+		__string(dev_name, dev_name(devlink_to_dev(devlink)))
+		__string(driver_name, devlink_to_dev(devlink)->driver->name)
 		__string(reporter_name, msg)
 		__string(msg, msg)
 	),
 
 	TP_fast_assign(
-		__assign_str(bus_name, devlink->dev->bus->name);
-		__assign_str(dev_name, dev_name(devlink->dev));
-		__assign_str(driver_name, devlink->dev->driver->name);
+		__assign_str(bus_name, devlink_to_dev(devlink)->bus->name);
+		__assign_str(dev_name, dev_name(devlink_to_dev(devlink)));
+		__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
 		__assign_str(reporter_name, reporter_name);
 		__assign_str(msg, msg);
 	),
···
 	TP_ARGS(devlink, reporter_name, health_state, time_since_last_recover),
 
 	TP_STRUCT__entry(
-		__string(bus_name, devlink->dev->bus->name)
-		__string(dev_name, dev_name(devlink->dev))
-		__string(driver_name, devlink->dev->driver->name)
+		__string(bus_name, devlink_to_dev(devlink)->bus->name)
+		__string(dev_name, dev_name(devlink_to_dev(devlink)))
+		__string(driver_name, devlink_to_dev(devlink)->driver->name)
 		__string(reporter_name, reporter_name)
 		__field(bool, health_state)
 		__field(u64, time_since_last_recover)
 	),
 
 	TP_fast_assign(
-		__assign_str(bus_name, devlink->dev->bus->name);
-		__assign_str(dev_name, dev_name(devlink->dev));
-		__assign_str(driver_name, devlink->dev->driver->name);
+		__assign_str(bus_name, devlink_to_dev(devlink)->bus->name);
+		__assign_str(dev_name, dev_name(devlink_to_dev(devlink)));
+		__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
 		__assign_str(reporter_name, reporter_name);
 		__entry->health_state = health_state;
 		__entry->time_since_last_recover = time_since_last_recover;
···
 	TP_ARGS(devlink, reporter_name, new_state),
 
 	TP_STRUCT__entry(
-		__string(bus_name, devlink->dev->bus->name)
-		__string(dev_name, dev_name(devlink->dev))
-		__string(driver_name, devlink->dev->driver->name)
+		__string(bus_name, devlink_to_dev(devlink)->bus->name)
+		__string(dev_name, dev_name(devlink_to_dev(devlink)))
+		__string(driver_name, devlink_to_dev(devlink)->driver->name)
 		__string(reporter_name, reporter_name)
 		__field(u8, new_state)
 	),
 
 	TP_fast_assign(
-		__assign_str(bus_name, devlink->dev->bus->name);
-		__assign_str(dev_name, dev_name(devlink->dev));
-		__assign_str(driver_name, devlink->dev->driver->name);
+		__assign_str(bus_name, devlink_to_dev(devlink)->bus->name);
+		__assign_str(dev_name, dev_name(devlink_to_dev(devlink)));
+		__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
 		__assign_str(reporter_name, reporter_name);
 		__entry->new_state = new_state;
 	),
···
 	TP_ARGS(devlink, skb, metadata),
 
 	TP_STRUCT__entry(
-		__string(bus_name, devlink->dev->bus->name)
-		__string(dev_name, dev_name(devlink->dev))
-		__string(driver_name, devlink->dev->driver->name)
+		__string(bus_name, devlink_to_dev(devlink)->bus->name)
+		__string(dev_name, dev_name(devlink_to_dev(devlink)))
+		__string(driver_name, devlink_to_dev(devlink)->driver->name)
 		__string(trap_name, metadata->trap_name)
 		__string(trap_group_name, metadata->trap_group_name)
 		__dynamic_array(char, input_dev_name, IFNAMSIZ)
···
 	TP_fast_assign(
 		struct net_device *input_dev = metadata->input_dev;
 
-		__assign_str(bus_name, devlink->dev->bus->name);
-		__assign_str(dev_name, dev_name(devlink->dev));
-		__assign_str(driver_name, devlink->dev->driver->name);
+		__assign_str(bus_name, devlink_to_dev(devlink)->bus->name);
+		__assign_str(dev_name, dev_name(devlink_to_dev(devlink)));
+		__assign_str(driver_name, devlink_to_dev(devlink)->driver->name);
 		__assign_str(trap_name, metadata->trap_name);
 		__assign_str(trap_group_name, metadata->trap_group_name);
 		__assign_str(input_dev_name,

net/core/devlink.c

···
 #define CREATE_TRACE_POINTS
 #include <trace/events/devlink.h>
 
+#define DEVLINK_RELOAD_STATS_ARRAY_SIZE \
+	(__DEVLINK_RELOAD_LIMIT_MAX * __DEVLINK_RELOAD_ACTION_MAX)
+
+struct devlink_dev_stats {
+	u32 reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
+	u32 remote_reload_stats[DEVLINK_RELOAD_STATS_ARRAY_SIZE];
+};
+
+struct devlink {
+	u32 index;
+	struct list_head port_list;
+	struct list_head rate_list;
+	struct list_head sb_list;
+	struct list_head dpipe_table_list;
+	struct list_head resource_list;
+	struct list_head param_list;
+	struct list_head region_list;
+	struct list_head reporter_list;
+	struct mutex reporters_lock; /* protects reporter_list */
+	struct devlink_dpipe_headers *dpipe_headers;
+	struct list_head trap_list;
+	struct list_head trap_group_list;
+	struct list_head trap_policer_list;
+	const struct devlink_ops *ops;
+	struct xarray snapshot_ids;
+	struct devlink_dev_stats stats;
+	struct device *dev;
+	possible_net_t _net;
+	/* Serializes access to devlink instance specific objects such as
+	 * port, sb, dpipe, resource, params, region, traps and more.
+	 */
+	struct mutex lock;
+	u8 reload_failed:1,
+	   reload_enabled:1;
+	refcount_t refcount;
+	struct completion comp;
+	char priv[0] __aligned(NETDEV_ALIGN);
+};
+
+void *devlink_priv(struct devlink *devlink)
+{
+	return &devlink->priv;
+}
+EXPORT_SYMBOL_GPL(devlink_priv);
+
+struct devlink *priv_to_devlink(void *priv)
+{
+	return container_of(priv, struct devlink, priv);
+}
+EXPORT_SYMBOL_GPL(priv_to_devlink);
+
+struct device *devlink_to_dev(const struct devlink *devlink)
+{
+	return devlink->dev;
+}
+EXPORT_SYMBOL_GPL(devlink_to_dev);
+
 static struct devlink_dpipe_field devlink_dpipe_fields_ethernet[] = {
 	{
 		.name = "destination mac",