devlink: Introduce rate object

Allow registering rate object for devlink ports with dedicated
devlink_rate_leaf_{create|destroy}() API. Implement new netlink
DEVLINK_CMD_RATE_GET command that is used to retrieve rate object info.
Add new DEVLINK_CMD_RATE_{NEW|DEL} commands that are used for
notifications when creating/deleting leaf rate object.

Rate API is intended to be used for rate limiting of individual
devlink ports (leafs) and their aggregates (nodes).

Example:

$ devlink port show
pci/0000:03:00.0/0
pci/0000:03:00.0/1

$ devlink port function rate show
pci/0000:03:00.0/0: type leaf
pci/0000:03:00.0/1: type leaf

Co-developed-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Dmytro Linkin <dlinkin@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 7c984ca..2f5954d 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -34,6 +34,7 @@ struct devlink_ops;
 struct devlink {
 	struct list_head list;
 	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;
@@ -133,6 +134,15 @@ struct devlink_port_attrs {
 	};
 };
 
+struct devlink_rate {
+	struct list_head list;
+	enum devlink_rate_type type;
+	struct devlink *devlink;
+	void *priv;
+
+	struct devlink_port *devlink_port;
+};
+
 struct devlink_port {
 	struct list_head list;
 	struct list_head param_list;
@@ -152,6 +162,8 @@ struct devlink_port {
 	struct delayed_work type_warn_dw;
 	struct list_head reporter_list;
 	struct mutex reporters_lock; /* Protects reporter_list */
+
+	struct devlink_rate *devlink_rate;
 };
 
 struct devlink_port_new_attrs {
@@ -1512,6 +1524,8 @@ void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port, u32 contro
 void devlink_port_attrs_pci_sf_set(struct devlink_port *devlink_port,
 				   u32 controller, u16 pf, u32 sf,
 				   bool external);
+int devlink_rate_leaf_create(struct devlink_port *port, void *priv);
+void devlink_rate_leaf_destroy(struct devlink_port *devlink_port);
 int devlink_sb_register(struct devlink *devlink, unsigned int sb_index,
 			u32 size, u16 ingress_pools_count,
 			u16 egress_pools_count, u16 ingress_tc_count,