xref: /linux/include/net/pkt_sched.h (revision 83a37b3292f4aca799b355179ad6fbdd78a08e10)
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 <linux/netdevice.h>
8 #include <net/sch_generic.h>
9 #include <net/net_namespace.h>
10 #include <uapi/linux/pkt_sched.h>
11 
12 #define DEFAULT_TX_QUEUE_LEN	1000
13 
14 struct qdisc_walker {
15 	int	stop;
16 	int	skip;
17 	int	count;
18 	int	(*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
19 };
20 
21 #define QDISC_ALIGNTO		64
22 #define QDISC_ALIGN(len)	(((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
23 
24 static inline void *qdisc_priv(struct Qdisc *q)
25 {
26 	return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
27 }
28 
29 /*
30    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
31 
32    Normal IP packet size ~ 512byte, hence:
33 
34    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
35    10Mbit ethernet.
36 
37    10msec resolution -> <50Kbit/sec.
38 
39    The result: [34]86 is not good choice for QoS router :-(
40 
41    The things are not so bad, because we may use artificial
42    clock evaluated by integration of network data flow
43    in the most critical places.
44  */
45 
46 typedef u64	psched_time_t;
47 typedef long	psched_tdiff_t;
48 
49 /* Avoid doing 64 bit divide */
50 #define PSCHED_SHIFT			6
51 #define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
52 #define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)
53 
54 #define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
55 #define PSCHED_PASTPERFECT		0
56 
57 static inline psched_time_t psched_get_time(void)
58 {
59 	return PSCHED_NS2TICKS(ktime_get_ns());
60 }
61 
62 static inline psched_tdiff_t
63 psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
64 {
65 	return min(tv1 - tv2, bound);
66 }
67 
68 struct qdisc_watchdog {
69 	u64		last_expires;
70 	struct hrtimer	timer;
71 	struct Qdisc	*qdisc;
72 };
73 
74 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
75 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
76 
77 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
78 					   psched_time_t expires)
79 {
80 	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
81 }
82 
83 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
84 
85 extern struct Qdisc_ops pfifo_qdisc_ops;
86 extern struct Qdisc_ops bfifo_qdisc_ops;
87 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
88 
89 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
90 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
91 			       unsigned int limit);
92 
93 int register_qdisc(struct Qdisc_ops *qops);
94 int unregister_qdisc(struct Qdisc_ops *qops);
95 void qdisc_get_default(char *id, size_t len);
96 int qdisc_set_default(const char *id);
97 
98 void qdisc_hash_add(struct Qdisc *q, bool invisible);
99 void qdisc_hash_del(struct Qdisc *q);
100 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
101 struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
102 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
103 					struct nlattr *tab);
104 void qdisc_put_rtab(struct qdisc_rate_table *tab);
105 void qdisc_put_stab(struct qdisc_size_table *tab);
106 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
107 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
108 		    struct net_device *dev, struct netdev_queue *txq,
109 		    spinlock_t *root_lock, bool validate);
110 
111 void __qdisc_run(struct Qdisc *q);
112 
113 static inline void qdisc_run(struct Qdisc *q)
114 {
115 	if (qdisc_run_begin(q))
116 		__qdisc_run(q);
117 }
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 static inline bool is_classid_clsact_ingress(u32 classid)
139 {
140 	/* This also returns true for ingress qdisc */
141 	return TC_H_MAJ(classid) == TC_H_MAJ(TC_H_CLSACT) &&
142 	       TC_H_MIN(classid) != TC_H_MIN(TC_H_MIN_EGRESS);
143 }
144 
145 static inline bool is_classid_clsact_egress(u32 classid)
146 {
147 	return TC_H_MAJ(classid) == TC_H_MAJ(TC_H_CLSACT) &&
148 	       TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_EGRESS);
149 }
150 
151 static inline struct net *qdisc_net(struct Qdisc *q)
152 {
153 	return dev_net(q->dev_queue->dev);
154 }
155 
156 #endif
157