text: #ifndef __NET_PKT_SCHED_H
  #define __NET_PKT_SCHED_H
  
  #include <linux/jiffies.h>
  #include <linux/ktime.h>
  #include <net/sch_generic.h>
  
  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_to_ns(ktime_get()));
  }
  
  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 {
  	struct hrtimer	timer;
  	struct Qdisc	*qdisc;
  };
  
  extern void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
  extern void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
  				    psched_time_t expires);
  extern 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;
  
  extern int fifo_set_limit(struct Qdisc *q, unsigned int limit);
  extern struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
  				      unsigned int limit);
  
  extern int register_qdisc(struct Qdisc_ops *qops);
  extern int unregister_qdisc(struct Qdisc_ops *qops);
  extern void qdisc_list_del(struct Qdisc *q);
  extern struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
  extern struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
  extern struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
  		struct nlattr *tab);
  extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
  extern void qdisc_put_stab(struct qdisc_size_table *tab);
  extern void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc);
  extern int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
  			   struct net_device *dev, struct netdev_queue *txq,
  			   spinlock_t *root_lock);
  
  extern void __qdisc_run(struct Qdisc *q);
  
  static inline void qdisc_run(struct Qdisc *q)
  {
  	if (qdisc_run_begin(q))
  		__qdisc_run(q);
  }
  
  extern int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
  			      struct tcf_result *res);
  extern int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
  		       struct tcf_result *res);
  
  /* 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;
  }
  
  #endif
  