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
  
  struct qdisc_walker {
  	int	stop;
  	int	skip;
  	int	count;
  	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  };
  
  #define QDISC_ALIGNTO		64
  #define QDISC_ALIGN(len)	(((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
  
  static inline void *qdisc_priv(struct Qdisc *q)
  {
  	return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
  }
  
  /* 
     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());
  }
  
  static inline psched_tdiff_t
  psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
  {
  	return min(tv1 - tv2, bound);
  }
  
  struct qdisc_watchdog {
  	u64		last_expires;
  	struct hrtimer	timer;
  	struct Qdisc	*qdisc;
  };
  
  void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
  void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
  
  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);
  
  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_class(struct net_device *dev, u32 handle);
  struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
  					struct nlattr *tab);
  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);
  int 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);
  }
  
  static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
  {
  	/* We need to take extra care in case the skb came via
  	 * vlan accelerated path. In that case, use skb->vlan_proto
  	 * as the original vlan header was already stripped.
  	 */
  	if (skb_vlan_tag_present(skb))
  		return skb->vlan_proto;
  	return skb->protocol;
  }
  
  /* 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;
  };
  
  #endif
  