text: /* SPDX-License-Identifier: GPL-2.0-or-later */
  /*
   * include/net/dsa.h - Driver for Distributed Switch Architecture switch chips
   * Copyright (c) 2008-2009 Marvell Semiconductor
   */
  
  #ifndef __LINUX_NET_DSA_H
  #define __LINUX_NET_DSA_H
  
  #include <linux/if.h>
  #include <linux/if_ether.h>
  #include <linux/list.h>
  #include <linux/notifier.h>
  #include <linux/timer.h>
  #include <linux/workqueue.h>
  #include <linux/of.h>
  #include <linux/ethtool.h>
  #include <linux/net_tstamp.h>
  #include <linux/phy.h>
  #include <linux/platform_data/dsa.h>
  #include <linux/phylink.h>
  #include <net/devlink.h>
  #include <net/switchdev.h>
  
  struct tc_action;
  struct phy_device;
  struct fixed_phy_status;
  struct phylink_link_state;
  
  #define DSA_TAG_PROTO_NONE_VALUE		0
  #define DSA_TAG_PROTO_BRCM_VALUE		1
  #define DSA_TAG_PROTO_BRCM_PREPEND_VALUE	2
  #define DSA_TAG_PROTO_DSA_VALUE			3
  #define DSA_TAG_PROTO_EDSA_VALUE		4
  #define DSA_TAG_PROTO_GSWIP_VALUE		5
  #define DSA_TAG_PROTO_KSZ9477_VALUE		6
  #define DSA_TAG_PROTO_KSZ9893_VALUE		7
  #define DSA_TAG_PROTO_LAN9303_VALUE		8
  #define DSA_TAG_PROTO_MTK_VALUE			9
  #define DSA_TAG_PROTO_QCA_VALUE			10
  #define DSA_TAG_PROTO_TRAILER_VALUE		11
  #define DSA_TAG_PROTO_8021Q_VALUE		12
  #define DSA_TAG_PROTO_SJA1105_VALUE		13
  #define DSA_TAG_PROTO_KSZ8795_VALUE		14
  #define DSA_TAG_PROTO_OCELOT_VALUE		15
  #define DSA_TAG_PROTO_AR9331_VALUE		16
  #define DSA_TAG_PROTO_RTL4_A_VALUE		17
  
  enum dsa_tag_protocol {
  	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
  	DSA_TAG_PROTO_BRCM		= DSA_TAG_PROTO_BRCM_VALUE,
  	DSA_TAG_PROTO_BRCM_PREPEND	= DSA_TAG_PROTO_BRCM_PREPEND_VALUE,
  	DSA_TAG_PROTO_DSA		= DSA_TAG_PROTO_DSA_VALUE,
  	DSA_TAG_PROTO_EDSA		= DSA_TAG_PROTO_EDSA_VALUE,
  	DSA_TAG_PROTO_GSWIP		= DSA_TAG_PROTO_GSWIP_VALUE,
  	DSA_TAG_PROTO_KSZ9477		= DSA_TAG_PROTO_KSZ9477_VALUE,
  	DSA_TAG_PROTO_KSZ9893		= DSA_TAG_PROTO_KSZ9893_VALUE,
  	DSA_TAG_PROTO_LAN9303		= DSA_TAG_PROTO_LAN9303_VALUE,
  	DSA_TAG_PROTO_MTK		= DSA_TAG_PROTO_MTK_VALUE,
  	DSA_TAG_PROTO_QCA		= DSA_TAG_PROTO_QCA_VALUE,
  	DSA_TAG_PROTO_TRAILER		= DSA_TAG_PROTO_TRAILER_VALUE,
  	DSA_TAG_PROTO_8021Q		= DSA_TAG_PROTO_8021Q_VALUE,
  	DSA_TAG_PROTO_SJA1105		= DSA_TAG_PROTO_SJA1105_VALUE,
  	DSA_TAG_PROTO_KSZ8795		= DSA_TAG_PROTO_KSZ8795_VALUE,
  	DSA_TAG_PROTO_OCELOT		= DSA_TAG_PROTO_OCELOT_VALUE,
  	DSA_TAG_PROTO_AR9331		= DSA_TAG_PROTO_AR9331_VALUE,
  	DSA_TAG_PROTO_RTL4_A		= DSA_TAG_PROTO_RTL4_A_VALUE,
  };
  
  struct packet_type;
  struct dsa_switch;
  
  struct dsa_device_ops {
  	struct sk_buff *(*xmit)(struct sk_buff *skb, struct net_device *dev);
  	struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev,
  			       struct packet_type *pt);
  	void (*flow_dissect)(const struct sk_buff *skb, __be16 *proto,
  			     int *offset);
  	/* Used to determine which traffic should match the DSA filter in
  	 * eth_type_trans, and which, if any, should bypass it and be processed
  	 * as regular on the master net device.
  	 */
  	bool (*filter)(const struct sk_buff *skb, struct net_device *dev);
  	unsigned int overhead;
  	const char *name;
  	enum dsa_tag_protocol proto;
  	/* Some tagging protocols either mangle or shift the destination MAC
  	 * address, in which case the DSA master would drop packets on ingress
  	 * if what it understands out of the destination MAC address is not in
  	 * its RX filter.
  	 */
  	bool promisc_on_master;
  	bool tail_tag;
  };
  
  /* This structure defines the control interfaces that are overlayed by the
   * DSA layer on top of the DSA CPU/management net_device instance. This is
   * used by the core net_device layer while calling various net_device_ops
   * function pointers.
   */
  struct dsa_netdevice_ops {
  	int (*ndo_do_ioctl)(struct net_device *dev, struct ifreq *ifr,
  			    int cmd);
  };
  
  #define DSA_TAG_DRIVER_ALIAS "dsa_tag-"
  #define MODULE_ALIAS_DSA_TAG_DRIVER(__proto)				\
  	MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __stringify(__proto##_VALUE))
  
  struct dsa_skb_cb {
  	struct sk_buff *clone;
  };
  
  struct __dsa_skb_cb {
  	struct dsa_skb_cb cb;
  	u8 priv[48 - sizeof(struct dsa_skb_cb)];
  };
  
  #define DSA_SKB_CB(skb) ((struct dsa_skb_cb *)((skb)->cb))
  
  #define DSA_SKB_CB_PRIV(skb)			\
  	((void *)(skb)->cb + offsetof(struct __dsa_skb_cb, priv))
  
  struct dsa_switch_tree {
  	struct list_head	list;
  
  	/* Notifier chain for switch-wide events */
  	struct raw_notifier_head	nh;
  
  	/* Tree identifier */
  	unsigned int index;
  
  	/* Number of switches attached to this tree */
  	struct kref refcount;
  
  	/* Has this tree been applied to the hardware? */
  	bool setup;
  
  	/*
  	 * Configuration data for the platform device that owns
  	 * this dsa switch tree instance.
  	 */
  	struct dsa_platform_data	*pd;
  
  	/* List of switch ports */
  	struct list_head ports;
  
  	/* List of DSA links composing the routing table */
  	struct list_head rtable;
  };
  
  /* TC matchall action types */
  enum dsa_port_mall_action_type {
  	DSA_PORT_MALL_MIRROR,
  	DSA_PORT_MALL_POLICER,
  };
  
  /* TC mirroring entry */
  struct dsa_mall_mirror_tc_entry {
  	u8 to_local_port;
  	bool ingress;
  };
  
  /* TC port policer entry */
  struct dsa_mall_policer_tc_entry {
  	u32 burst;
  	u64 rate_bytes_per_sec;
  };
  
  /* TC matchall entry */
  struct dsa_mall_tc_entry {
  	struct list_head list;
  	unsigned long cookie;
  	enum dsa_port_mall_action_type type;
  	union {
  		struct dsa_mall_mirror_tc_entry mirror;
  		struct dsa_mall_policer_tc_entry policer;
  	};
  };
  
  
  struct dsa_port {
  	/* A CPU port is physically connected to a master device.
  	 * A user port exposed to userspace has a slave device.
  	 */
  	union {
  		struct net_device *master;
  		struct net_device *slave;
  	};
  
  	/* CPU port tagging operations used by master or slave devices */
  	const struct dsa_device_ops *tag_ops;
  
  	/* Copies for faster access in master receive hot path */
  	struct dsa_switch_tree *dst;
  	struct sk_buff *(*rcv)(struct sk_buff *skb, struct net_device *dev,
  			       struct packet_type *pt);
  	bool (*filter)(const struct sk_buff *skb, struct net_device *dev);
  
  	enum {
  		DSA_PORT_TYPE_UNUSED = 0,
  		DSA_PORT_TYPE_CPU,
  		DSA_PORT_TYPE_DSA,
  		DSA_PORT_TYPE_USER,
  	} type;
  
  	struct dsa_switch	*ds;
  	unsigned int		index;
  	const char		*name;
  	struct dsa_port		*cpu_dp;
  	const char		*mac;
  	struct device_node	*dn;
  	unsigned int		ageing_time;
  	bool			vlan_filtering;
  	u8			stp_state;
  	struct net_device	*bridge_dev;
  	struct devlink_port	devlink_port;
  	bool			devlink_port_setup;
  	struct phylink		*pl;
  	struct phylink_config	pl_config;
  
  	struct list_head list;
  
  	/*
  	 * Give the switch driver somewhere to hang its per-port private data
  	 * structures (accessible from the tagger).
  	 */
  	void *priv;
  
  	/*
  	 * Original copy of the master netdev ethtool_ops
  	 */
  	const struct ethtool_ops *orig_ethtool_ops;
  
  	/*
  	 * Original copy of the master netdev net_device_ops
  	 */
  	const struct dsa_netdevice_ops *netdev_ops;
  
  	bool setup;
  };
  
  /* TODO: ideally DSA ports would have a single dp->link_dp member,
   * and no dst->rtable nor this struct dsa_link would be needed,
   * but this would require some more complex tree walking,
   * so keep it stupid at the moment and list them all.
   */
  struct dsa_link {
  	struct dsa_port *dp;
  	struct dsa_port *link_dp;
  	struct list_head list;
  };
  
  struct dsa_switch {
  	bool setup;
  
  	struct device *dev;
  
  	/*
  	 * Parent switch tree, and switch index.
  	 */
  	struct dsa_switch_tree	*dst;
  	unsigned int		index;
  
  	/* Listener for switch fabric events */
  	struct notifier_block	nb;
  
  	/*
  	 * Give the switch driver somewhere to hang its private data
  	 * structure.
  	 */
  	void *priv;
  
  	/*
  	 * Configuration data for this switch.
  	 */
  	struct dsa_chip_data	*cd;
  
  	/*
  	 * The switch operations.
  	 */
  	const struct dsa_switch_ops	*ops;
  
  	/*
  	 * Slave mii_bus and devices for the individual ports.
  	 */
  	u32			phys_mii_mask;
  	struct mii_bus		*slave_mii_bus;
  
  	/* Ageing Time limits in msecs */
  	unsigned int ageing_time_min;
  	unsigned int ageing_time_max;
  
  	/* devlink used to represent this switch device */
  	struct devlink		*devlink;
  
  	/* Number of switch port queues */
  	unsigned int		num_tx_queues;
  
  	/* Disallow bridge core from requesting different VLAN awareness
  	 * settings on ports if not hardware-supported
  	 */
  	bool			vlan_filtering_is_global;
  
  	/* Pass .port_vlan_add and .port_vlan_del to drivers even for bridges
  	 * that have vlan_filtering=0. All drivers should ideally set this (and
  	 * then the option would get removed), but it is unknown whether this
  	 * would break things or not.
  	 */
  	bool			configure_vlan_while_not_filtering;
  
  	/* If the switch driver always programs the CPU port as egress tagged
  	 * despite the VLAN configuration indicating otherwise, then setting
  	 * @untag_bridge_pvid will force the DSA receive path to pop the bridge's
  	 * default_pvid VLAN tagged frames to offer a consistent behavior
  	 * between a vlan_filtering=0 and vlan_filtering=1 bridge device.
  	 */
  	bool			untag_bridge_pvid;
  
  	/* In case vlan_filtering_is_global is set, the VLAN awareness state
  	 * should be retrieved from here and not from the per-port settings.
  	 */
  	bool			vlan_filtering;
  
  	/* MAC PCS does not provide link state change interrupt, and requires
  	 * polling. Flag passed on to PHYLINK.
  	 */
  	bool			pcs_poll;
  
  	/* For switches that only have the MRU configurable. To ensure the
  	 * configured MTU is not exceeded, normalization of MRU on all bridged
  	 * interfaces is needed.
  	 */
  	bool			mtu_enforcement_ingress;
  
  	size_t num_ports;
  };
  
  static inline struct dsa_port *dsa_to_port(struct dsa_switch *ds, int p)
  {
  	struct dsa_switch_tree *dst = ds->dst;
  	struct dsa_port *dp;
  
  	list_for_each_entry(dp, &dst->ports, list)
  		if (dp->ds == ds && dp->index == p)
  			return dp;
  
  	return NULL;
  }
  
  static inline bool dsa_is_unused_port(struct dsa_switch *ds, int p)
  {
  	return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_UNUSED;
  }
  
  static inline bool dsa_is_cpu_port(struct dsa_switch *ds, int p)
  {
  	return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_CPU;
  }
  
  static inline bool dsa_is_dsa_port(struct dsa_switch *ds, int p)
  {
  	return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_DSA;
  }
  
  static inline bool dsa_is_user_port(struct dsa_switch *ds, int p)
  {
  	return dsa_to_port(ds, p)->type == DSA_PORT_TYPE_USER;
  }
  
  static inline u32 dsa_user_ports(struct dsa_switch *ds)
  {
  	u32 mask = 0;
  	int p;
  
  	for (p = 0; p < ds->num_ports; p++)
  		if (dsa_is_user_port(ds, p))
  			mask |= BIT(p);
  
  	return mask;
  }
  
  /* Return the local port used to reach an arbitrary switch device */
  static inline unsigned int dsa_routing_port(struct dsa_switch *ds, int device)
  {
  	struct dsa_switch_tree *dst = ds->dst;
  	struct dsa_link *dl;
  
  	list_for_each_entry(dl, &dst->rtable, list)
  		if (dl->dp->ds == ds && dl->link_dp->ds->index == device)
  			return dl->dp->index;
  
  	return ds->num_ports;
  }
  
  /* Return the local port used to reach an arbitrary switch port */
  static inline unsigned int dsa_towards_port(struct dsa_switch *ds, int device,
  					    int port)
  {
  	if (device == ds->index)
  		return port;
  	else
  		return dsa_routing_port(ds, device);
  }
  
  /* Return the local port used to reach the dedicated CPU port */
  static inline unsigned int dsa_upstream_port(struct dsa_switch *ds, int port)
  {
  	const struct dsa_port *dp = dsa_to_port(ds, port);
  	const struct dsa_port *cpu_dp = dp->cpu_dp;
  
  	if (!cpu_dp)
  		return port;
  
  	return dsa_towards_port(ds, cpu_dp->ds->index, cpu_dp->index);
  }
  
  static inline bool dsa_port_is_vlan_filtering(const struct dsa_port *dp)
  {
  	const struct dsa_switch *ds = dp->ds;
  
  	if (ds->vlan_filtering_is_global)
  		return ds->vlan_filtering;
  	else
  		return dp->vlan_filtering;
  }
  
  typedef int dsa_fdb_dump_cb_t(const unsigned char *addr, u16 vid,
  			      bool is_static, void *data);
  struct dsa_switch_ops {
  	enum dsa_tag_protocol (*get_tag_protocol)(struct dsa_switch *ds,
  						  int port,
  						  enum dsa_tag_protocol mprot);
  
  	int	(*setup)(struct dsa_switch *ds);
  	void	(*teardown)(struct dsa_switch *ds);
  	u32	(*get_phy_flags)(struct dsa_switch *ds, int port);
  
  	/*
  	 * Access to the switch's PHY registers.
  	 */
  	int	(*phy_read)(struct dsa_switch *ds, int port, int regnum);
  	int	(*phy_write)(struct dsa_switch *ds, int port,
  			     int regnum, u16 val);
  
  	/*
  	 * Link state adjustment (called from libphy)
  	 */
  	void	(*adjust_link)(struct dsa_switch *ds, int port,
  				struct phy_device *phydev);
  	void	(*fixed_link_update)(struct dsa_switch *ds, int port,
  				struct fixed_phy_status *st);
  
  	/*
  	 * PHYLINK integration
  	 */
  	void	(*phylink_validate)(struct dsa_switch *ds, int port,
  				    unsigned long *supported,
  				    struct phylink_link_state *state);
  	int	(*phylink_mac_link_state)(struct dsa_switch *ds, int port,
  					  struct phylink_link_state *state);
  	void	(*phylink_mac_config)(struct dsa_switch *ds, int port,
  				      unsigned int mode,
  				      const struct phylink_link_state *state);
  	void	(*phylink_mac_an_restart)(struct dsa_switch *ds, int port);
  	void	(*phylink_mac_link_down)(struct dsa_switch *ds, int port,
  					 unsigned int mode,
  					 phy_interface_t interface);
  	void	(*phylink_mac_link_up)(struct dsa_switch *ds, int port,
  				       unsigned int mode,
  				       phy_interface_t interface,
  				       struct phy_device *phydev,
  				       int speed, int duplex,
  				       bool tx_pause, bool rx_pause);
  	void	(*phylink_fixed_state)(struct dsa_switch *ds, int port,
  				       struct phylink_link_state *state);
  	/*
  	 * ethtool hardware statistics.
  	 */
  	void	(*get_strings)(struct dsa_switch *ds, int port,
  			       u32 stringset, uint8_t *data);
  	void	(*get_ethtool_stats)(struct dsa_switch *ds,
  				     int port, uint64_t *data);
  	int	(*get_sset_count)(struct dsa_switch *ds, int port, int sset);
  	void	(*get_ethtool_phy_stats)(struct dsa_switch *ds,
  					 int port, uint64_t *data);
  
  	/*
  	 * ethtool Wake-on-LAN
  	 */
  	void	(*get_wol)(struct dsa_switch *ds, int port,
  			   struct ethtool_wolinfo *w);
  	int	(*set_wol)(struct dsa_switch *ds, int port,
  			   struct ethtool_wolinfo *w);
  
  	/*
  	 * ethtool timestamp info
  	 */
  	int	(*get_ts_info)(struct dsa_switch *ds, int port,
  			       struct ethtool_ts_info *ts);
  
  	/*
  	 * Suspend and resume
  	 */
  	int	(*suspend)(struct dsa_switch *ds);
  	int	(*resume)(struct dsa_switch *ds);
  
  	/*
  	 * Port enable/disable
  	 */
  	int	(*port_enable)(struct dsa_switch *ds, int port,
  			       struct phy_device *phy);
  	void	(*port_disable)(struct dsa_switch *ds, int port);
  
  	/*
  	 * Port's MAC EEE settings
  	 */
  	int	(*set_mac_eee)(struct dsa_switch *ds, int port,
  			       struct ethtool_eee *e);
  	int	(*get_mac_eee)(struct dsa_switch *ds, int port,
  			       struct ethtool_eee *e);
  
  	/* EEPROM access */
  	int	(*get_eeprom_len)(struct dsa_switch *ds);
  	int	(*get_eeprom)(struct dsa_switch *ds,
  			      struct ethtool_eeprom *eeprom, u8 *data);
  	int	(*set_eeprom)(struct dsa_switch *ds,
  			      struct ethtool_eeprom *eeprom, u8 *data);
  
  	/*
  	 * Register access.
  	 */
  	int	(*get_regs_len)(struct dsa_switch *ds, int port);
  	void	(*get_regs)(struct dsa_switch *ds, int port,
  			    struct ethtool_regs *regs, void *p);
  
  	/*
  	 * Bridge integration
  	 */
  	int	(*set_ageing_time)(struct dsa_switch *ds, unsigned int msecs);
  	int	(*port_bridge_join)(struct dsa_switch *ds, int port,
  				    struct net_device *bridge);
  	void	(*port_bridge_leave)(struct dsa_switch *ds, int port,
  				     struct net_device *bridge);
  	void	(*port_stp_state_set)(struct dsa_switch *ds, int port,
  				      u8 state);
  	void	(*port_fast_age)(struct dsa_switch *ds, int port);
  	int	(*port_egress_floods)(struct dsa_switch *ds, int port,
  				      bool unicast, bool multicast);
  
  	/*
  	 * VLAN support
  	 */
  	int	(*port_vlan_filtering)(struct dsa_switch *ds, int port,
  				       bool vlan_filtering,
  				       struct switchdev_trans *trans);
  	int (*port_vlan_prepare)(struct dsa_switch *ds, int port,
  				 const struct switchdev_obj_port_vlan *vlan);
  	void (*port_vlan_add)(struct dsa_switch *ds, int port,
  			      const struct switchdev_obj_port_vlan *vlan);
  	int	(*port_vlan_del)(struct dsa_switch *ds, int port,
  				 const struct switchdev_obj_port_vlan *vlan);
  	/*
  	 * Forwarding database
  	 */
  	int	(*port_fdb_add)(struct dsa_switch *ds, int port,
  				const unsigned char *addr, u16 vid);
  	int	(*port_fdb_del)(struct dsa_switch *ds, int port,
  				const unsigned char *addr, u16 vid);
  	int	(*port_fdb_dump)(struct dsa_switch *ds, int port,
  				 dsa_fdb_dump_cb_t *cb, void *data);
  
  	/*
  	 * Multicast database
  	 */
  	int (*port_mdb_prepare)(struct dsa_switch *ds, int port,
  				const struct switchdev_obj_port_mdb *mdb);
  	void (*port_mdb_add)(struct dsa_switch *ds, int port,
  			     const struct switchdev_obj_port_mdb *mdb);
  	int	(*port_mdb_del)(struct dsa_switch *ds, int port,
  				const struct switchdev_obj_port_mdb *mdb);
  	/*
  	 * RXNFC
  	 */
  	int	(*get_rxnfc)(struct dsa_switch *ds, int port,
  			     struct ethtool_rxnfc *nfc, u32 *rule_locs);
  	int	(*set_rxnfc)(struct dsa_switch *ds, int port,
  			     struct ethtool_rxnfc *nfc);
  
  	/*
  	 * TC integration
  	 */
  	int	(*cls_flower_add)(struct dsa_switch *ds, int port,
  				  struct flow_cls_offload *cls, bool ingress);
  	int	(*cls_flower_del)(struct dsa_switch *ds, int port,
  				  struct flow_cls_offload *cls, bool ingress);
  	int	(*cls_flower_stats)(struct dsa_switch *ds, int port,
  				    struct flow_cls_offload *cls, bool ingress);
  	int	(*port_mirror_add)(struct dsa_switch *ds, int port,
  				   struct dsa_mall_mirror_tc_entry *mirror,
  				   bool ingress);
  	void	(*port_mirror_del)(struct dsa_switch *ds, int port,
  				   struct dsa_mall_mirror_tc_entry *mirror);
  	int	(*port_policer_add)(struct dsa_switch *ds, int port,
  				    struct dsa_mall_policer_tc_entry *policer);
  	void	(*port_policer_del)(struct dsa_switch *ds, int port);
  	int	(*port_setup_tc)(struct dsa_switch *ds, int port,
  				 enum tc_setup_type type, void *type_data);
  
  	/*
  	 * Cross-chip operations
  	 */
  	int	(*crosschip_bridge_join)(struct dsa_switch *ds, int tree_index,
  					 int sw_index, int port,
  					 struct net_device *br);
  	void	(*crosschip_bridge_leave)(struct dsa_switch *ds, int tree_index,
  					  int sw_index, int port,
  					  struct net_device *br);
  
  	/*
  	 * PTP functionality
  	 */
  	int	(*port_hwtstamp_get)(struct dsa_switch *ds, int port,
  				     struct ifreq *ifr);
  	int	(*port_hwtstamp_set)(struct dsa_switch *ds, int port,
  				     struct ifreq *ifr);
  	bool	(*port_txtstamp)(struct dsa_switch *ds, int port,
  				 struct sk_buff *clone, unsigned int type);
  	bool	(*port_rxtstamp)(struct dsa_switch *ds, int port,
  				 struct sk_buff *skb, unsigned int type);
  
  	/* Devlink parameters, etc */
  	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);
  	int	(*devlink_info_get)(struct dsa_switch *ds,
  				    struct devlink_info_req *req,
  				    struct netlink_ext_ack *extack);
  
  	/*
  	 * MTU change functionality. Switches can also adjust their MRU through
  	 * this method. By MTU, one understands the SDU (L2 payload) length.
  	 * If the switch needs to account for the DSA tag on the CPU port, this
  	 * method needs to do so privately.
  	 */
  	int	(*port_change_mtu)(struct dsa_switch *ds, int port,
  				   int new_mtu);
  	int	(*port_max_mtu)(struct dsa_switch *ds, int port);
  };
  
  #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);
  int dsa_devlink_resource_register(struct dsa_switch *ds,
  				  const char *resource_name,
  				  u64 resource_size,
  				  u64 resource_id,
  				  u64 parent_resource_id,
  				  const struct devlink_resource_size_params *size_params);
  
  void dsa_devlink_resources_unregister(struct dsa_switch *ds);
  
  void dsa_devlink_resource_occ_get_register(struct dsa_switch *ds,
  					   u64 resource_id,
  					   devlink_resource_occ_get_t *occ_get,
  					   void *occ_get_priv);
  void dsa_devlink_resource_occ_get_unregister(struct dsa_switch *ds,
  					     u64 resource_id);
  struct devlink_region *
  dsa_devlink_region_create(struct dsa_switch *ds,
  			  const struct devlink_region_ops *ops,
  			  u32 region_max_snapshots, u64 region_size);
  struct devlink_region *
  dsa_devlink_port_region_create(struct dsa_switch *ds,
  			       int port,
  			       const struct devlink_port_region_ops *ops,
  			       u32 region_max_snapshots, u64 region_size);
  void dsa_devlink_region_destroy(struct devlink_region *region);
  
  struct dsa_port *dsa_port_from_netdev(struct net_device *netdev);
  
  struct dsa_devlink_priv {
  	struct dsa_switch *ds;
  };
  
  static inline struct dsa_switch *dsa_devlink_to_ds(struct devlink *dl)
  {
  	struct dsa_devlink_priv *dl_priv = devlink_priv(dl);
  
  	return dl_priv->ds;
  }
  
  static inline
  struct dsa_switch *dsa_devlink_port_to_ds(struct devlink_port *port)
  {
  	struct devlink *dl = port->devlink;
  	struct dsa_devlink_priv *dl_priv = devlink_priv(dl);
  
  	return dl_priv->ds;
  }
  
  static inline int dsa_devlink_port_to_port(struct devlink_port *port)
  {
  	return port->index;
  }
  
  struct dsa_switch_driver {
  	struct list_head	list;
  	const struct dsa_switch_ops *ops;
  };
  
  struct net_device *dsa_dev_to_net_device(struct device *dev);
  
  /* Keep inline for faster access in hot path */
  static inline bool netdev_uses_dsa(const struct net_device *dev)
  {
  #if IS_ENABLED(CONFIG_NET_DSA)
  	return dev->dsa_ptr && dev->dsa_ptr->rcv;
  #endif
  	return false;
  }
  
  static inline bool dsa_can_decode(const struct sk_buff *skb,
  				  struct net_device *dev)
  {
  #if IS_ENABLED(CONFIG_NET_DSA)
  	return !dev->dsa_ptr->filter || dev->dsa_ptr->filter(skb, dev);
  #endif
  	return false;
  }
  
  /* All DSA tags that push the EtherType to the right (basically all except tail
   * tags, which don't break dissection) can be treated the same from the
   * perspective of the flow dissector.
   *
   * We need to return:
   *  - offset: the (B - A) difference between:
   *    A. the position of the real EtherType and
   *    B. the current skb->data (aka ETH_HLEN bytes into the frame, aka 2 bytes
   *       after the normal EtherType was supposed to be)
   *    The offset in bytes is exactly equal to the tagger overhead (and half of
   *    that, in __be16 shorts).
   *
   *  - proto: the value of the real EtherType.
   */
  static inline void dsa_tag_generic_flow_dissect(const struct sk_buff *skb,
  						__be16 *proto, int *offset)
  {
  #if IS_ENABLED(CONFIG_NET_DSA)
  	const struct dsa_device_ops *ops = skb->dev->dsa_ptr->tag_ops;
  	int tag_len = ops->overhead;
  
  	*offset = tag_len;
  	*proto = ((__be16 *)skb->data)[(tag_len / 2) - 1];
  #endif
  }
  
  #if IS_ENABLED(CONFIG_NET_DSA)
  static inline int __dsa_netdevice_ops_check(struct net_device *dev)
  {
  	int err = -EOPNOTSUPP;
  
  	if (!dev->dsa_ptr)
  		return err;
  
  	if (!dev->dsa_ptr->netdev_ops)
  		return err;
  
  	return 0;
  }
  
  static inline int dsa_ndo_do_ioctl(struct net_device *dev, struct ifreq *ifr,
  				   int cmd)
  {
  	const struct dsa_netdevice_ops *ops;
  	int err;
  
  	err = __dsa_netdevice_ops_check(dev);
  	if (err)
  		return err;
  
  	ops = dev->dsa_ptr->netdev_ops;
  
  	return ops->ndo_do_ioctl(dev, ifr, cmd);
  }
  #else
  static inline int dsa_ndo_do_ioctl(struct net_device *dev, struct ifreq *ifr,
  				   int cmd)
  {
  	return -EOPNOTSUPP;
  }
  #endif
  
  void dsa_unregister_switch(struct dsa_switch *ds);
  int dsa_register_switch(struct dsa_switch *ds);
  struct dsa_switch *dsa_switch_find(int tree_index, int sw_index);
  #ifdef CONFIG_PM_SLEEP
  int dsa_switch_suspend(struct dsa_switch *ds);
  int dsa_switch_resume(struct dsa_switch *ds);
  #else
  static inline int dsa_switch_suspend(struct dsa_switch *ds)
  {
  	return 0;
  }
  static inline int dsa_switch_resume(struct dsa_switch *ds)
  {
  	return 0;
  }
  #endif /* CONFIG_PM_SLEEP */
  
  enum dsa_notifier_type {
  	DSA_PORT_REGISTER,
  	DSA_PORT_UNREGISTER,
  };
  
  struct dsa_notifier_info {
  	struct net_device *dev;
  };
  
  struct dsa_notifier_register_info {
  	struct dsa_notifier_info info;	/* must be first */
  	struct net_device *master;
  	unsigned int port_number;
  	unsigned int switch_number;
  };
  
  static inline struct net_device *
  dsa_notifier_info_to_dev(const struct dsa_notifier_info *info)
  {
  	return info->dev;
  }
  
  #if IS_ENABLED(CONFIG_NET_DSA)
  int register_dsa_notifier(struct notifier_block *nb);
  int unregister_dsa_notifier(struct notifier_block *nb);
  int call_dsa_notifiers(unsigned long val, struct net_device *dev,
  		       struct dsa_notifier_info *info);
  #else
  static inline int register_dsa_notifier(struct notifier_block *nb)
  {
  	return 0;
  }
  
  static inline int unregister_dsa_notifier(struct notifier_block *nb)
  {
  	return 0;
  }
  
  static inline int call_dsa_notifiers(unsigned long val, struct net_device *dev,
  				     struct dsa_notifier_info *info)
  {
  	return NOTIFY_DONE;
  }
  #endif
  
  /* Broadcom tag specific helpers to insert and extract queue/port number */
  #define BRCM_TAG_SET_PORT_QUEUE(p, q)	((p) << 8 | q)
  #define BRCM_TAG_GET_PORT(v)		((v) >> 8)
  #define BRCM_TAG_GET_QUEUE(v)		((v) & 0xff)
  
  
  netdev_tx_t dsa_enqueue_skb(struct sk_buff *skb, struct net_device *dev);
  int dsa_port_get_phy_strings(struct dsa_port *dp, uint8_t *data);
  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
  
  