xref: /linux/include/net/pkt_sched.h (revision 93df8a1ed6231727c5db94a80b1a6bd5ee67cec3)
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 <linux/if_vlan.h>
7 #include <net/sch_generic.h>
8 
9 struct qdisc_walker {
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		64
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 artificial
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_get_ns());
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 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
69 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires, bool throttle);
70 
71 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
72 					   psched_time_t expires)
73 {
74 	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires), true);
75 }
76 
77 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
78 
79 extern struct Qdisc_ops pfifo_qdisc_ops;
80 extern struct Qdisc_ops bfifo_qdisc_ops;
81 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
82 
83 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
84 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
85 			       unsigned int limit);
86 
87 int register_qdisc(struct Qdisc_ops *qops);
88 int unregister_qdisc(struct Qdisc_ops *qops);
89 void qdisc_get_default(char *id, size_t len);
90 int qdisc_set_default(const char *id);
91 
92 void qdisc_list_add(struct Qdisc *q);
93 void qdisc_list_del(struct Qdisc *q);
94 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
95 struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
96 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
97 					struct nlattr *tab);
98 void qdisc_put_rtab(struct qdisc_rate_table *tab);
99 void qdisc_put_stab(struct qdisc_size_table *tab);
100 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
101 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
102 		    struct net_device *dev, struct netdev_queue *txq,
103 		    spinlock_t *root_lock, bool validate);
104 
105 void __qdisc_run(struct Qdisc *q);
106 
107 static inline void qdisc_run(struct Qdisc *q)
108 {
109 	if (qdisc_run_begin(q))
110 		__qdisc_run(q);
111 }
112 
113 int tc_classify_compat(struct sk_buff *skb, const struct tcf_proto *tp,
114 		       struct tcf_result *res);
115 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
116 		struct tcf_result *res);
117 
118 static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
119 {
120 	/* We need to take extra care in case the skb came via
121 	 * vlan accelerated path. In that case, use skb->vlan_proto
122 	 * as the original vlan header was already stripped.
123 	 */
124 	if (skb_vlan_tag_present(skb))
125 		return skb->vlan_proto;
126 	return skb->protocol;
127 }
128 
129 /* Calculate maximal size of packet seen by hard_start_xmit
130    routine of this device.
131  */
132 static inline unsigned int psched_mtu(const struct net_device *dev)
133 {
134 	return dev->mtu + dev->hard_header_len;
135 }
136 
137 #endif
138