xref: /linux/include/net/pkt_sched.h (revision c98be0c96db00e9b6b02d31e0fa7590c54cdaaac)
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 	int	stop;
10 	int	skip;
11 	int	count;
12 	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
13 };
14 
15 #define QDISC_ALIGNTO		64
16 #define QDISC_ALIGN(len)	(((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
17 
18 static inline void *qdisc_priv(struct Qdisc *q)
19 {
20 	return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
21 }
22 
23 /*
24    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
25 
26    Normal IP packet size ~ 512byte, hence:
27 
28    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
29    10Mbit ethernet.
30 
31    10msec resolution -> <50Kbit/sec.
32 
33    The result: [34]86 is not good choice for QoS router :-(
34 
35    The things are not so bad, because we may use artificial
36    clock evaluated by integration of network data flow
37    in the most critical places.
38  */
39 
40 typedef u64	psched_time_t;
41 typedef long	psched_tdiff_t;
42 
43 /* Avoid doing 64 bit divide */
44 #define PSCHED_SHIFT			6
45 #define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
46 #define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)
47 
48 #define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
49 #define PSCHED_PASTPERFECT		0
50 
51 static inline psched_time_t psched_get_time(void)
52 {
53 	return PSCHED_NS2TICKS(ktime_to_ns(ktime_get()));
54 }
55 
56 static inline psched_tdiff_t
57 psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
58 {
59 	return min(tv1 - tv2, bound);
60 }
61 
62 struct qdisc_watchdog {
63 	struct hrtimer	timer;
64 	struct Qdisc	*qdisc;
65 };
66 
67 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
68 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
69 
70 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
71 					   psched_time_t expires)
72 {
73 	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
74 }
75 
76 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
77 
78 extern struct Qdisc_ops pfifo_qdisc_ops;
79 extern struct Qdisc_ops bfifo_qdisc_ops;
80 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
81 
82 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
83 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
84 			       unsigned int limit);
85 
86 int register_qdisc(struct Qdisc_ops *qops);
87 int unregister_qdisc(struct Qdisc_ops *qops);
88 void qdisc_get_default(char *id, size_t len);
89 int qdisc_set_default(const char *id);
90 
91 void qdisc_list_add(struct Qdisc *q);
92 void qdisc_list_del(struct Qdisc *q);
93 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
94 struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
95 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
96 					struct nlattr *tab);
97 void qdisc_put_rtab(struct qdisc_rate_table *tab);
98 void qdisc_put_stab(struct qdisc_size_table *tab);
99 void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc);
100 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
101 		    struct net_device *dev, struct netdev_queue *txq,
102 		    spinlock_t *root_lock);
103 
104 void __qdisc_run(struct Qdisc *q);
105 
106 static inline void qdisc_run(struct Qdisc *q)
107 {
108 	if (qdisc_run_begin(q))
109 		__qdisc_run(q);
110 }
111 
112 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
113 		       struct tcf_result *res);
114 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
115 		struct tcf_result *res);
116 
117 /* Calculate maximal size of packet seen by hard_start_xmit
118    routine of this device.
119  */
120 static inline unsigned int psched_mtu(const struct net_device *dev)
121 {
122 	return dev->mtu + dev->hard_header_len;
123 }
124 
125 #endif
126