net: dsa: Add support for devlink device parameters

Add plumbing to allow DSA drivers to register parameters with devlink.

To keep with the abstraction, the DSA drivers pass the ds structure to
these helpers, and the DSA core then translates that to the devlink
structure associated to the device.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -550,6 +550,29 @@ struct dsa_switch_ops {
 	 */
 	netdev_tx_t (*port_deferred_xmit)(struct dsa_switch *ds, int port,
 					  struct sk_buff *skb);
+	/* Devlink parameters */
+	int	(*devlink_param_get)(struct dsa_switch *ds, u32 id,
+				     struct devlink_param_gset_ctx *ctx);
+	int	(*devlink_param_set)(struct dsa_switch *ds, u32 id,
+				     struct devlink_param_gset_ctx *ctx);
+};
+
+#define DSA_DEVLINK_PARAM_DRIVER(_id, _name, _type, _cmodes)		\
+	DEVLINK_PARAM_DRIVER(_id, _name, _type, _cmodes,		\
+			     dsa_devlink_param_get, dsa_devlink_param_set, NULL)
+
+int dsa_devlink_param_get(struct devlink *dl, u32 id,
+			  struct devlink_param_gset_ctx *ctx);
+int dsa_devlink_param_set(struct devlink *dl, u32 id,
+			  struct devlink_param_gset_ctx *ctx);
+int dsa_devlink_params_register(struct dsa_switch *ds,
+				const struct devlink_param *params,
+				size_t params_count);
+void dsa_devlink_params_unregister(struct dsa_switch *ds,
+				   const struct devlink_param *params,
+				   size_t params_count);
+struct dsa_devlink_priv {
+	struct dsa_switch *ds;
 };
 
 struct dsa_switch_driver {

net/dsa/dsa.c

@@ -331,6 +331,54 @@ int call_dsa_notifiers(unsigned long val, struct net_device *dev,
 }
 EXPORT_SYMBOL_GPL(call_dsa_notifiers);
 
+int dsa_devlink_param_get(struct devlink *dl, u32 id,
+			  struct devlink_param_gset_ctx *ctx)
+{
+	struct dsa_devlink_priv *dl_priv;
+	struct dsa_switch *ds;
+
+	dl_priv = devlink_priv(dl);
+	ds = dl_priv->ds;
+
+	if (!ds->ops->devlink_param_get)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_param_get(ds, id, ctx);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_param_get);
+
+int dsa_devlink_param_set(struct devlink *dl, u32 id,
+			  struct devlink_param_gset_ctx *ctx)
+{
+	struct dsa_devlink_priv *dl_priv;
+	struct dsa_switch *ds;
+
+	dl_priv = devlink_priv(dl);
+	ds = dl_priv->ds;
+
+	if (!ds->ops->devlink_param_set)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_param_set(ds, id, ctx);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_param_set);
+
+int dsa_devlink_params_register(struct dsa_switch *ds,
+				const struct devlink_param *params,
+				size_t params_count)
+{
+	return devlink_params_register(ds->devlink, params, params_count);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_params_register);
+
+void dsa_devlink_params_unregister(struct dsa_switch *ds,
+				   const struct devlink_param *params,
+				   size_t params_count)
+{
+	devlink_params_unregister(ds->devlink, params, params_count);
+}
+EXPORT_SYMBOL_GPL(dsa_devlink_params_unregister);
+
 static int __init dsa_init_module(void)
 {
 	int rc;

net/dsa/dsa2.c

@@ -349,6 +349,7 @@ static void dsa_port_teardown(struct dsa_port *dp)
 
 static int dsa_switch_setup(struct dsa_switch *ds)
 {
+	struct dsa_devlink_priv *dl_priv;
 	int err;
 
 	if (ds->setup)
@@ -364,9 +365,11 @@ static int dsa_switch_setup(struct dsa_switch *ds)
 	/* Add the switch to devlink before calling setup, so that setup can
 	 * add dpipe tables
 	 */
-	ds->devlink = devlink_alloc(&dsa_devlink_ops, 0);
+	ds->devlink = devlink_alloc(&dsa_devlink_ops, sizeof(*dl_priv));
 	if (!ds->devlink)
 		return -ENOMEM;
+	dl_priv = devlink_priv(ds->devlink);
+	dl_priv->ds = ds;
 
 	err = devlink_register(ds->devlink, ds->dev);
 	if (err)
@@ -380,6 +383,8 @@ static int dsa_switch_setup(struct dsa_switch *ds)
 	if (err < 0)
 		goto unregister_notifier;
 
+	devlink_params_publish(ds->devlink);
+
 	if (!ds->slave_mii_bus && ds->ops->phy_read) {
 		ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev);
 		if (!ds->slave_mii_bus) {