xref: /linux/include/net/pkt_sched.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 #define DEFAULT_TX_QUEUE_LEN	1000
10 
11 struct qdisc_walker {
12 	int	stop;
13 	int	skip;
14 	int	count;
15 	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
16 };
17 
18 #define QDISC_ALIGNTO		64
19 #define QDISC_ALIGN(len)	(((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
20 
21 static inline void *qdisc_priv(struct Qdisc *q)
22 {
23 	return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
24 }
25 
26 /*
27    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
28 
29    Normal IP packet size ~ 512byte, hence:
30 
31    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
32    10Mbit ethernet.
33 
34    10msec resolution -> <50Kbit/sec.
35 
36    The result: [34]86 is not good choice for QoS router :-(
37 
38    The things are not so bad, because we may use artificial
39    clock evaluated by integration of network data flow
40    in the most critical places.
41  */
42 
43 typedef u64	psched_time_t;
44 typedef long	psched_tdiff_t;
45 
46 /* Avoid doing 64 bit divide */
47 #define PSCHED_SHIFT			6
48 #define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
49 #define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)
50 
51 #define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
52 #define PSCHED_PASTPERFECT		0
53 
54 static inline psched_time_t psched_get_time(void)
55 {
56 	return PSCHED_NS2TICKS(ktime_get_ns());
57 }
58 
59 static inline psched_tdiff_t
60 psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
61 {
62 	return min(tv1 - tv2, bound);
63 }
64 
65 struct qdisc_watchdog {
66 	u64		last_expires;
67 	struct hrtimer	timer;
68 	struct Qdisc	*qdisc;
69 };
70 
71 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
72 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
73 
74 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
75 					   psched_time_t expires)
76 {
77 	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
78 }
79 
80 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
81 
82 extern struct Qdisc_ops pfifo_qdisc_ops;
83 extern struct Qdisc_ops bfifo_qdisc_ops;
84 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
85 
86 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
87 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
88 			       unsigned int limit);
89 
90 int register_qdisc(struct Qdisc_ops *qops);
91 int unregister_qdisc(struct Qdisc_ops *qops);
92 void qdisc_get_default(char *id, size_t len);
93 int qdisc_set_default(const char *id);
94 
95 void qdisc_hash_add(struct Qdisc *q);
96 void qdisc_hash_del(struct Qdisc *q);
97 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
98 struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
99 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
100 					struct nlattr *tab);
101 void qdisc_put_rtab(struct qdisc_rate_table *tab);
102 void qdisc_put_stab(struct qdisc_size_table *tab);
103 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
104 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
105 		    struct net_device *dev, struct netdev_queue *txq,
106 		    spinlock_t *root_lock, bool validate);
107 
108 void __qdisc_run(struct Qdisc *q);
109 
110 static inline void qdisc_run(struct Qdisc *q)
111 {
112 	if (qdisc_run_begin(q))
113 		__qdisc_run(q);
114 }
115 
116 int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
117 		struct tcf_result *res, bool compat_mode);
118 
119 static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
120 {
121 	/* We need to take extra care in case the skb came via
122 	 * vlan accelerated path. In that case, use skb->vlan_proto
123 	 * as the original vlan header was already stripped.
124 	 */
125 	if (skb_vlan_tag_present(skb))
126 		return skb->vlan_proto;
127 	return skb->protocol;
128 }
129 
130 /* Calculate maximal size of packet seen by hard_start_xmit
131    routine of this device.
132  */
133 static inline unsigned int psched_mtu(const struct net_device *dev)
134 {
135 	return dev->mtu + dev->hard_header_len;
136 }
137 
138 #endif
139