xref: /linux/include/net/pkt_sched.h (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
1 #ifndef __NET_PKT_SCHED_H
2 #define __NET_PKT_SCHED_H
3 
4 #include <linux/jiffies.h>
5 #include <linux/ktime.h>
6 #include <net/sch_generic.h>
7 
8 struct qdisc_walker
9 {
10 	int	stop;
11 	int	skip;
12 	int	count;
13 	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
14 };
15 
16 #define QDISC_ALIGNTO		32
17 #define QDISC_ALIGN(len)	(((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
18 
19 static inline void *qdisc_priv(struct Qdisc *q)
20 {
21 	return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
22 }
23 
24 /*
25    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
26 
27    Normal IP packet size ~ 512byte, hence:
28 
29    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
30    10Mbit ethernet.
31 
32    10msec resolution -> <50Kbit/sec.
33 
34    The result: [34]86 is not good choice for QoS router :-(
35 
36    The things are not so bad, because we may use artifical
37    clock evaluated by integration of network data flow
38    in the most critical places.
39  */
40 
41 typedef u64	psched_time_t;
42 typedef long	psched_tdiff_t;
43 
44 /* Avoid doing 64 bit divide */
45 #define PSCHED_SHIFT			6
46 #define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
47 #define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)
48 
49 #define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
50 #define PSCHED_PASTPERFECT		0
51 
52 static inline psched_time_t psched_get_time(void)
53 {
54 	return PSCHED_NS2TICKS(ktime_to_ns(ktime_get()));
55 }
56 
57 static inline psched_tdiff_t
58 psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
59 {
60 	return min(tv1 - tv2, bound);
61 }
62 
63 struct qdisc_watchdog {
64 	struct hrtimer	timer;
65 	struct Qdisc	*qdisc;
66 };
67 
68 extern void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
69 extern void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
70 				    psched_time_t expires);
71 extern void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
72 
73 extern struct Qdisc_ops pfifo_qdisc_ops;
74 extern struct Qdisc_ops bfifo_qdisc_ops;
75 
76 extern int fifo_set_limit(struct Qdisc *q, unsigned int limit);
77 extern struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
78 				      unsigned int limit);
79 
80 extern int register_qdisc(struct Qdisc_ops *qops);
81 extern int unregister_qdisc(struct Qdisc_ops *qops);
82 extern void qdisc_list_del(struct Qdisc *q);
83 extern struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
84 extern struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
85 extern struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
86 		struct nlattr *tab);
87 extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
88 extern void qdisc_put_stab(struct qdisc_size_table *tab);
89 extern void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc);
90 extern int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
91 			   struct net_device *dev, struct netdev_queue *txq,
92 			   spinlock_t *root_lock);
93 
94 extern void __qdisc_run(struct Qdisc *q);
95 
96 static inline void qdisc_run(struct Qdisc *q)
97 {
98 	if (!test_and_set_bit(__QDISC_STATE_RUNNING, &q->state))
99 		__qdisc_run(q);
100 }
101 
102 extern int tc_classify_compat(struct sk_buff *skb, struct tcf_proto *tp,
103 			      struct tcf_result *res);
104 extern int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
105 		       struct tcf_result *res);
106 
107 /* Calculate maximal size of packet seen by hard_start_xmit
108    routine of this device.
109  */
110 static inline unsigned psched_mtu(const struct net_device *dev)
111 {
112 	return dev->mtu + dev->hard_header_len;
113 }
114 
115 #endif
116