1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __NET_PKT_SCHED_H
3#define __NET_PKT_SCHED_H
4
5#include <linux/jiffies.h>
6#include <linux/ktime.h>
7#include <linux/if_vlan.h>
8#include <linux/netdevice.h>
9#include <net/sch_generic.h>
10#include <net/net_namespace.h>
11#include <uapi/linux/pkt_sched.h>
12
13#define DEFAULT_TX_QUEUE_LEN 1000
14#define STAB_SIZE_LOG_MAX 30
15
16struct qdisc_walker {
17 int stop;
18 int skip;
19 int count;
20 int (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
21};
22
23#define qdisc_priv(q) \
24 _Generic(q, \
25 const struct Qdisc * : (const void *)&q->privdata, \
26 struct Qdisc * : (void *)&q->privdata)
27
28/*
29 Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
30
31 Normal IP packet size ~ 512byte, hence:
32
33 0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
34 10Mbit ethernet.
35
36 10msec resolution -> <50Kbit/sec.
37
38 The result: [34]86 is not good choice for QoS router :-(
39
40 The things are not so bad, because we may use artificial
41 clock evaluated by integration of network data flow
42 in the most critical places.
43 */
44
45typedef u64 psched_time_t;
46
47/* Avoid doing 64 bit divide */
48#define PSCHED_SHIFT 6
49#define PSCHED_TICKS2NS(x) ((s64)(x) << PSCHED_SHIFT)
50#define PSCHED_NS2TICKS(x) ((x) >> PSCHED_SHIFT)
51
52#define PSCHED_TICKS_PER_SEC PSCHED_NS2TICKS(NSEC_PER_SEC)
53#define PSCHED_PASTPERFECT 0
54
55static inline psched_time_t psched_get_time(void)
56{
57 return PSCHED_NS2TICKS(ktime_get_ns());
58}
59
60struct qdisc_watchdog {
61 struct hrtimer timer;
62 struct Qdisc *qdisc;
63};
64
65void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
66 clockid_t clockid);
67void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
68
69void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
70 u64 delta_ns);
71
72static inline void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd,
73 u64 expires)
74{
75 return qdisc_watchdog_schedule_range_ns(wd, expires, delta_ns: 0ULL);
76}
77
78static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
79 psched_time_t expires)
80{
81 qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
82}
83
84void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
85
86extern struct Qdisc_ops pfifo_qdisc_ops;
87extern struct Qdisc_ops bfifo_qdisc_ops;
88extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
89
90int fifo_set_limit(struct Qdisc *q, unsigned int limit);
91struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
92 unsigned int limit,
93 struct netlink_ext_ack *extack);
94
95int register_qdisc(struct Qdisc_ops *qops);
96void unregister_qdisc(struct Qdisc_ops *qops);
97#define NET_SCH_ALIAS_PREFIX "net-sch-"
98#define MODULE_ALIAS_NET_SCH(id) MODULE_ALIAS(NET_SCH_ALIAS_PREFIX id)
99void qdisc_get_default(char *id, size_t len);
100int qdisc_set_default(const char *id);
101
102void qdisc_hash_add(struct Qdisc *q, bool invisible);
103void qdisc_hash_del(struct Qdisc *q);
104struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
105struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);
106struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
107 struct nlattr *tab,
108 struct netlink_ext_ack *extack);
109void qdisc_put_rtab(struct qdisc_rate_table *tab);
110void qdisc_put_stab(struct qdisc_size_table *tab);
111bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
112 struct net_device *dev, struct netdev_queue *txq,
113 spinlock_t *root_lock, bool validate);
114
115void __qdisc_run(struct Qdisc *q);
116
117static inline struct sk_buff *qdisc_run(struct Qdisc *q)
118{
119 if (qdisc_run_begin(qdisc: q)) {
120 __qdisc_run(q);
121 return qdisc_run_end(qdisc: q);
122 }
123 return NULL;
124}
125
126extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
127
128/* Calculate maximal size of packet seen by hard_start_xmit
129 routine of this device.
130 */
131static inline unsigned int psched_mtu(const struct net_device *dev)
132{
133 return READ_ONCE(dev->mtu) + dev->hard_header_len;
134}
135
136static inline struct net *qdisc_net(struct Qdisc *q)
137{
138 return dev_net(dev: q->dev_queue->dev);
139}
140
141struct tc_query_caps_base {
142 enum tc_setup_type type;
143 void *caps;
144};
145
146struct tc_cbs_qopt_offload {
147 u8 enable;
148 s32 queue;
149 s32 hicredit;
150 s32 locredit;
151 s32 idleslope;
152 s32 sendslope;
153};
154
155struct tc_etf_qopt_offload {
156 u8 enable;
157 s32 queue;
158};
159
160struct tc_mqprio_caps {
161 bool validate_queue_counts:1;
162};
163
164struct tc_mqprio_qopt_offload {
165 /* struct tc_mqprio_qopt must always be the first element */
166 struct tc_mqprio_qopt qopt;
167 struct netlink_ext_ack *extack;
168 u16 mode;
169 u16 shaper;
170 u32 flags;
171 u64 min_rate[TC_QOPT_MAX_QUEUE];
172 u64 max_rate[TC_QOPT_MAX_QUEUE];
173 unsigned long preemptible_tcs;
174};
175
176struct tc_taprio_caps {
177 bool supports_queue_max_sdu:1;
178 bool gate_mask_per_txq:1;
179 /* Device expects lower TXQ numbers to have higher priority over higher
180 * TXQs, regardless of their TC mapping. DO NOT USE FOR NEW DRIVERS,
181 * INSTEAD ENFORCE A PROPER TC:TXQ MAPPING COMING FROM USER SPACE.
182 */
183 bool broken_mqprio:1;
184};
185
186enum tc_taprio_qopt_cmd {
187 TAPRIO_CMD_REPLACE,
188 TAPRIO_CMD_DESTROY,
189 TAPRIO_CMD_STATS,
190 TAPRIO_CMD_QUEUE_STATS,
191};
192
193/**
194 * struct tc_taprio_qopt_stats - IEEE 802.1Qbv statistics
195 * @window_drops: Frames that were dropped because they were too large to be
196 * transmitted in any of the allotted time windows (open gates) for their
197 * traffic class.
198 * @tx_overruns: Frames still being transmitted by the MAC after the
199 * transmission gate associated with their traffic class has closed.
200 * Equivalent to `12.29.1.1.2 TransmissionOverrun` from 802.1Q-2018.
201 */
202struct tc_taprio_qopt_stats {
203 u64 window_drops;
204 u64 tx_overruns;
205};
206
207struct tc_taprio_qopt_queue_stats {
208 int queue;
209 struct tc_taprio_qopt_stats stats;
210};
211
212struct tc_taprio_sched_entry {
213 u8 command; /* TC_TAPRIO_CMD_* */
214
215 /* The gate_mask in the offloading side refers to traffic classes */
216 u32 gate_mask;
217 u32 interval;
218};
219
220struct tc_taprio_qopt_offload {
221 enum tc_taprio_qopt_cmd cmd;
222
223 union {
224 /* TAPRIO_CMD_STATS */
225 struct tc_taprio_qopt_stats stats;
226 /* TAPRIO_CMD_QUEUE_STATS */
227 struct tc_taprio_qopt_queue_stats queue_stats;
228 /* TAPRIO_CMD_REPLACE */
229 struct {
230 struct tc_mqprio_qopt_offload mqprio;
231 struct netlink_ext_ack *extack;
232 ktime_t base_time;
233 u64 cycle_time;
234 u64 cycle_time_extension;
235 u32 max_sdu[TC_MAX_QUEUE];
236
237 size_t num_entries;
238 struct tc_taprio_sched_entry entries[];
239 };
240 };
241};
242
243#if IS_ENABLED(CONFIG_NET_SCH_TAPRIO)
244
245/* Reference counting */
246struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
247 *offload);
248void taprio_offload_free(struct tc_taprio_qopt_offload *offload);
249
250#else
251
252/* Reference counting */
253static inline struct tc_taprio_qopt_offload *
254taprio_offload_get(struct tc_taprio_qopt_offload *offload)
255{
256 return NULL;
257}
258
259static inline void taprio_offload_free(struct tc_taprio_qopt_offload *offload)
260{
261}
262
263#endif
264
265/* Ensure skb_mstamp_ns, which might have been populated with the txtime, is
266 * not mistaken for a software timestamp, because this will otherwise prevent
267 * the dispatch of hardware timestamps to the socket.
268 */
269static inline void skb_txtime_consumed(struct sk_buff *skb)
270{
271 skb->tstamp = ktime_set(secs: 0, nsecs: 0);
272}
273
274static inline bool tc_qdisc_stats_dump(struct Qdisc *sch,
275 unsigned long cl,
276 struct qdisc_walker *arg)
277{
278 if (arg->count >= arg->skip && arg->fn(sch, cl, arg) < 0) {
279 arg->stop = 1;
280 return false;
281 }
282
283 arg->count++;
284 return true;
285}
286
287static inline void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc)
288{
289 if (!(qdisc->flags & TCQ_F_WARN_NONWC)) {
290 pr_warn("%s: %s qdisc %X: is non-work-conserving?\n",
291 txt, qdisc->ops->id, qdisc->handle >> 16);
292 qdisc->flags |= TCQ_F_WARN_NONWC;
293 }
294}
295
296static inline unsigned int qdisc_peek_len(struct Qdisc *sch)
297{
298 struct sk_buff *skb;
299 unsigned int len;
300
301 skb = sch->ops->peek(sch);
302 if (unlikely(skb == NULL)) {
303 qdisc_warn_nonwc(txt: "qdisc_peek_len", qdisc: sch);
304 return 0;
305 }
306 len = qdisc_pkt_len(skb);
307
308 return len;
309}
310
311#endif
312

source code of linux/include/net/pkt_sched.h