devlink: Add devlink_param for port register and unregister

Add functions to register and unregister for the driver supported
configuration parameters table per port.

v7->v8:
- Order the definitions following way as suggested by Jiri.
__devlink_params_register
__devlink_params_unregister
devlink_params_register
devlink_params_unregister
devlink_port_params_register
devlink_port_params_unregister
- Append with Acked-by: Jiri Pirko <jiri@mellanox.com>.

v2->v3:
- Add a helper __devlink_params_register() with common code used by
  both devlink_params_register() and devlink_port_params_register().

Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Vasundhara Volam <vasundhara-v.volam@broadcom.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/devlink.h

@@ -48,6 +48,7 @@ struct devlink_port_attrs {
 
 struct devlink_port {
 	struct list_head list;
+	struct list_head param_list;
 	struct devlink *devlink;
 	unsigned index;
 	bool registered;
@@ -567,6 +568,12 @@ int devlink_params_register(struct devlink *devlink,
 void devlink_params_unregister(struct devlink *devlink,
 			       const struct devlink_param *params,
 			       size_t params_count);
+int devlink_port_params_register(struct devlink_port *devlink_port,
+				 const struct devlink_param *params,
+				 size_t params_count);
+void devlink_port_params_unregister(struct devlink_port *devlink_port,
+				    const struct devlink_param *params,
+				    size_t params_count);
 int devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
 				       union devlink_param_value *init_val);
 int devlink_param_driverinit_value_set(struct devlink *devlink, u32 param_id,
@@ -791,6 +798,21 @@ devlink_params_unregister(struct devlink *devlink,
 
 }
 
+static inline int
+devlink_port_params_register(struct devlink_port *devlink_port,
+			     const struct devlink_param *params,
+			     size_t params_count)
+{
+	return 0;
+}
+
+static inline void
+devlink_port_params_unregister(struct devlink_port *devlink_port,
+			       const struct devlink_param *params,
+			       size_t params_count)
+{
+}
+
 static inline int
 devlink_param_driverinit_value_get(struct devlink *devlink, u32 param_id,
 				   union devlink_param_value *init_val)

net/core/devlink.c

@@ -3147,12 +3147,12 @@ static int devlink_nl_cmd_param_set_doit(struct sk_buff *skb,
 }
 
 static int devlink_param_register_one(struct devlink *devlink,
+				      struct list_head *param_list,
 				      const struct devlink_param *param)
 {
 	struct devlink_param_item *param_item;
 
-	if (devlink_param_find_by_name(&devlink->param_list,
-				       param->name))
+	if (devlink_param_find_by_name(param_list, param->name))
 		return -EEXIST;
 
 	if (param->supported_cmodes == BIT(DEVLINK_PARAM_CMODE_DRIVERINIT))
@@ -3165,18 +3165,18 @@ static int devlink_param_register_one(struct devlink *devlink,
 		return -ENOMEM;
 	param_item->param = param;
 
-	list_add_tail(&param_item->list, &devlink->param_list);
+	list_add_tail(&param_item->list, param_list);
 	devlink_param_notify(devlink, param_item, DEVLINK_CMD_PARAM_NEW);
 	return 0;
 }
 
 static void devlink_param_unregister_one(struct devlink *devlink,
+					 struct list_head *param_list,
 					 const struct devlink_param *param)
 {
 	struct devlink_param_item *param_item;
 
-	param_item = devlink_param_find_by_name(&devlink->param_list,
-						param->name);
+	param_item = devlink_param_find_by_name(param_list, param->name);
 	WARN_ON(!param_item);
 	devlink_param_notify(devlink, param_item, DEVLINK_CMD_PARAM_DEL);
 	list_del(&param_item->list);
@@ -3954,6 +3954,7 @@ int devlink_port_register(struct devlink *devlink,
 	devlink_port->index = port_index;
 	devlink_port->registered = true;
 	list_add_tail(&devlink_port->list, &devlink->port_list);
+	INIT_LIST_HEAD(&devlink_port->param_list);
 	mutex_unlock(&devlink->lock);
 	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
 	return 0;
@@ -4471,16 +4472,18 @@ void devlink_resource_occ_get_unregister(struct devlink *devlink,
 }
 EXPORT_SYMBOL_GPL(devlink_resource_occ_get_unregister);
 
-/**
- *	devlink_params_register - register configuration parameters
- *
- *	@devlink: devlink
- *	@params: configuration parameters array
- *	@params_count: number of parameters provided
- *
- *	Register the configuration parameters supported by the driver.
- */
-int devlink_params_register(struct devlink *devlink,
+static int devlink_param_verify(const struct devlink_param *param)
+{
+	if (!param || !param->name || !param->supported_cmodes)
+		return -EINVAL;
+	if (param->generic)
+		return devlink_param_generic_verify(param);
+	else
+		return devlink_param_driver_verify(param);
+}
+
+static int __devlink_params_register(struct devlink *devlink,
+				     struct list_head *param_list,
 				     const struct devlink_param *params,
 				     size_t params_count)
 {
@@ -4490,20 +4493,11 @@ int devlink_params_register(struct devlink *devlink,
 
 	mutex_lock(&devlink->lock);
 	for (i = 0; i < params_count; i++, param++) {
-		if (!param || !param->name || !param->supported_cmodes) {
-			err = -EINVAL;
-			goto rollback;
-		}
-		if (param->generic) {
-			err = devlink_param_generic_verify(param);
+		err = devlink_param_verify(param);
 		if (err)
 			goto rollback;
-		} else {
-			err = devlink_param_driver_verify(param);
-			if (err)
-				goto rollback;
-		}
-		err = devlink_param_register_one(devlink, param);
+
+		err = devlink_param_register_one(devlink, param_list, param);
 		if (err)
 			goto rollback;
 	}
@@ -4515,11 +4509,42 @@ int devlink_params_register(struct devlink *devlink,
 	if (!i)
 		goto unlock;
 	for (param--; i > 0; i--, param--)
-		devlink_param_unregister_one(devlink, param);
+		devlink_param_unregister_one(devlink, param_list, param);
 unlock:
 	mutex_unlock(&devlink->lock);
 	return err;
 }
+
+static void __devlink_params_unregister(struct devlink *devlink,
+					struct list_head *param_list,
+					const struct devlink_param *params,
+					size_t params_count)
+{
+	const struct devlink_param *param = params;
+	int i;
+
+	mutex_lock(&devlink->lock);
+	for (i = 0; i < params_count; i++, param++)
+		devlink_param_unregister_one(devlink, param_list, param);
+	mutex_unlock(&devlink->lock);
+}
+
+/**
+ *	devlink_params_register - register configuration parameters
+ *
+ *	@devlink: devlink
+ *	@params: configuration parameters array
+ *	@params_count: number of parameters provided
+ *
+ *	Register the configuration parameters supported by the driver.
+ */
+int devlink_params_register(struct devlink *devlink,
+			    const struct devlink_param *params,
+			    size_t params_count)
+{
+	return __devlink_params_register(devlink, &devlink->param_list, params,
+					 params_count);
+}
 EXPORT_SYMBOL_GPL(devlink_params_register);
 
 /**
@@ -4532,16 +4557,48 @@ void devlink_params_unregister(struct devlink *devlink,
 			       const struct devlink_param *params,
 			       size_t params_count)
 {
-	const struct devlink_param *param = params;
-	int i;
-
-	mutex_lock(&devlink->lock);
-	for (i = 0; i < params_count; i++, param++)
-		devlink_param_unregister_one(devlink, param);
-	mutex_unlock(&devlink->lock);
+	return __devlink_params_unregister(devlink, &devlink->param_list,
+					   params, params_count);
 }
 EXPORT_SYMBOL_GPL(devlink_params_unregister);
 
+/**
+ *	devlink_port_params_register - register port configuration parameters
+ *
+ *	@devlink_port: devlink port
+ *	@params: configuration parameters array
+ *	@params_count: number of parameters provided
+ *
+ *	Register the configuration parameters supported by the port.
+ */
+int devlink_port_params_register(struct devlink_port *devlink_port,
+				 const struct devlink_param *params,
+				 size_t params_count)
+{
+	return __devlink_params_register(devlink_port->devlink,
+					 &devlink_port->param_list, params,
+					 params_count);
+}
+EXPORT_SYMBOL_GPL(devlink_port_params_register);
+
+/**
+ *	devlink_port_params_unregister - unregister port configuration
+ *	parameters
+ *
+ *	@devlink_port: devlink port
+ *	@params: configuration parameters array
+ *	@params_count: number of parameters provided
+ */
+void devlink_port_params_unregister(struct devlink_port *devlink_port,
+				    const struct devlink_param *params,
+				    size_t params_count)
+{
+	return __devlink_params_unregister(devlink_port->devlink,
+					   &devlink_port->param_list,
+					   params, params_count);
+}
+EXPORT_SYMBOL_GPL(devlink_port_params_unregister);
+
 /**
  *	devlink_param_driverinit_value_get - get configuration parameter
  *					     value for driver initializing