text: /* SPDX-License-Identifier: GPL-2.0 */
  #ifndef __NET_PKT_SCHED_H
  #define __NET_PKT_SCHED_H
  
  #include <linux/jiffies.h>
  #include <linux/ktime.h>
  #include <linux/if_vlan.h>
  #include <linux/netdevice.h>
  #include <net/sch_generic.h>
  #include <net/net_namespace.h>
  #include <uapi/linux/pkt_sched.h>
  
  #define DEFAULT_TX_QUEUE_LEN	1000
  #define STAB_SIZE_LOG_MAX	30
  
  struct qdisc_walker {
  	int	stop;
  	int	skip;
  	int	count;
  	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  };
  
  static inline void *qdisc_priv(struct Qdisc *q)
  {
  	return &q->privdata;
  }
  
  static inline struct Qdisc *qdisc_from_priv(void *priv)
  {
  	return container_of(priv, struct Qdisc, privdata);
  }
  
  /* 
     Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
     
     Normal IP packet size ~ 512byte, hence:
  
     0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
     10Mbit ethernet.
  
     10msec resolution -> <50Kbit/sec.
     
     The result: [34]86 is not good choice for QoS router :-(
  
     The things are not so bad, because we may use artificial
     clock evaluated by integration of network data flow
     in the most critical places.
   */
  
  typedef u64	psched_time_t;
  typedef long	psched_tdiff_t;
  
  /* Avoid doing 64 bit divide */
  #define PSCHED_SHIFT			6
  #define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
  #define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)
  
  #define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
  #define PSCHED_PASTPERFECT		0
  
  static inline psched_time_t psched_get_time(void)
  {
  	return PSCHED_NS2TICKS(ktime_get_ns());
  }
  
  struct qdisc_watchdog {
  	u64		last_expires;
  	struct hrtimer	timer;
  	struct Qdisc	*qdisc;
  };
  
  void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
  				 clockid_t clockid);
  void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
  
  void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
  				      u64 delta_ns);
  
  static inline void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd,
  					      u64 expires)
  {
  	return qdisc_watchdog_schedule_range_ns(wd, expires, 0ULL);
  }
  
  static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
  					   psched_time_t expires)
  {
  	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
  }
  
  void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
  
  extern struct Qdisc_ops pfifo_qdisc_ops;
  extern struct Qdisc_ops bfifo_qdisc_ops;
  extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
  
  int fifo_set_limit(struct Qdisc *q, unsigned int limit);
  struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
  			       unsigned int limit,
  			       struct netlink_ext_ack *extack);
  
  int register_qdisc(struct Qdisc_ops *qops);
  int unregister_qdisc(struct Qdisc_ops *qops);
  void qdisc_get_default(char *id, size_t len);
  int qdisc_set_default(const char *id);
  
  void qdisc_hash_add(struct Qdisc *q, bool invisible);
  void qdisc_hash_del(struct Qdisc *q);
  struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
  struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);
  struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
  					struct nlattr *tab,
  					struct netlink_ext_ack *extack);
  void qdisc_put_rtab(struct qdisc_rate_table *tab);
  void qdisc_put_stab(struct qdisc_size_table *tab);
  void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
  bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
  		     struct net_device *dev, struct netdev_queue *txq,
  		     spinlock_t *root_lock, bool validate);
  
  void __qdisc_run(struct Qdisc *q);
  
  static inline void qdisc_run(struct Qdisc *q)
  {
  	if (qdisc_run_begin(q)) {
  		__qdisc_run(q);
  		qdisc_run_end(q);
  	}
  }
  
  /* Calculate maximal size of packet seen by hard_start_xmit
     routine of this device.
   */
  static inline unsigned int psched_mtu(const struct net_device *dev)
  {
  	return dev->mtu + dev->hard_header_len;
  }
  
  static inline struct net *qdisc_net(struct Qdisc *q)
  {
  	return dev_net(q->dev_queue->dev);
  }
  
  struct tc_cbs_qopt_offload {
  	u8 enable;
  	s32 queue;
  	s32 hicredit;
  	s32 locredit;
  	s32 idleslope;
  	s32 sendslope;
  };
  
  struct tc_etf_qopt_offload {
  	u8 enable;
  	s32 queue;
  };
  
  struct tc_taprio_sched_entry {
  	u8 command; /* TC_TAPRIO_CMD_* */
  
  	/* The gate_mask in the offloading side refers to traffic classes */
  	u32 gate_mask;
  	u32 interval;
  };
  
  struct tc_taprio_qopt_offload {
  	u8 enable;
  	ktime_t base_time;
  	u64 cycle_time;
  	u64 cycle_time_extension;
  
  	size_t num_entries;
  	struct tc_taprio_sched_entry entries[];
  };
  
  /* Reference counting */
  struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
  						  *offload);
  void taprio_offload_free(struct tc_taprio_qopt_offload *offload);
  
  /* Ensure skb_mstamp_ns, which might have been populated with the txtime, is
   * not mistaken for a software timestamp, because this will otherwise prevent
   * the dispatch of hardware timestamps to the socket.
   */
  static inline void skb_txtime_consumed(struct sk_buff *skb)
  {
  	skb->tstamp = ktime_set(0, 0);
  }
  
  struct tc_skb_cb {
  	struct qdisc_skb_cb qdisc_cb;
  
  	u16 mru;
  	u8 post_ct:1;
  	u8 post_ct_snat:1;
  	u8 post_ct_dnat:1;
  	u16 zone; /* Only valid if post_ct = true */
  };
  
  static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)
  {
  	struct tc_skb_cb *cb = (struct tc_skb_cb *)skb->cb;
  
  	BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));
  	return cb;
  }
  
  #endif
  