xref: /openbmc/linux/include/net/pkt_sched.h (revision 0c6dfa75)
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 
16 struct 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 static inline void *qdisc_priv(struct Qdisc *q)
24 {
25 	return &q->privdata;
26 }
27 
28 static inline struct Qdisc *qdisc_from_priv(void *priv)
29 {
30 	return container_of(priv, struct Qdisc, privdata);
31 }
32 
33 /*
34    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
35 
36    Normal IP packet size ~ 512byte, hence:
37 
38    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
39    10Mbit ethernet.
40 
41    10msec resolution -> <50Kbit/sec.
42 
43    The result: [34]86 is not good choice for QoS router :-(
44 
45    The things are not so bad, because we may use artificial
46    clock evaluated by integration of network data flow
47    in the most critical places.
48  */
49 
50 typedef u64	psched_time_t;
51 typedef long	psched_tdiff_t;
52 
53 /* Avoid doing 64 bit divide */
54 #define PSCHED_SHIFT			6
55 #define PSCHED_TICKS2NS(x)		((s64)(x) << PSCHED_SHIFT)
56 #define PSCHED_NS2TICKS(x)		((x) >> PSCHED_SHIFT)
57 
58 #define PSCHED_TICKS_PER_SEC		PSCHED_NS2TICKS(NSEC_PER_SEC)
59 #define PSCHED_PASTPERFECT		0
60 
61 static inline psched_time_t psched_get_time(void)
62 {
63 	return PSCHED_NS2TICKS(ktime_get_ns());
64 }
65 
66 struct qdisc_watchdog {
67 	struct hrtimer	timer;
68 	struct Qdisc	*qdisc;
69 };
70 
71 void qdisc_watchdog_init_clockid(struct qdisc_watchdog *wd, struct Qdisc *qdisc,
72 				 clockid_t clockid);
73 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
74 
75 void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires,
76 				      u64 delta_ns);
77 
78 static inline void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd,
79 					      u64 expires)
80 {
81 	return qdisc_watchdog_schedule_range_ns(wd, expires, 0ULL);
82 }
83 
84 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
85 					   psched_time_t expires)
86 {
87 	qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
88 }
89 
90 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
91 
92 extern struct Qdisc_ops pfifo_qdisc_ops;
93 extern struct Qdisc_ops bfifo_qdisc_ops;
94 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
95 
96 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
97 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
98 			       unsigned int limit,
99 			       struct netlink_ext_ack *extack);
100 
101 int register_qdisc(struct Qdisc_ops *qops);
102 void unregister_qdisc(struct Qdisc_ops *qops);
103 void qdisc_get_default(char *id, size_t len);
104 int qdisc_set_default(const char *id);
105 
106 void qdisc_hash_add(struct Qdisc *q, bool invisible);
107 void qdisc_hash_del(struct Qdisc *q);
108 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
109 struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);
110 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
111 					struct nlattr *tab,
112 					struct netlink_ext_ack *extack);
113 void qdisc_put_rtab(struct qdisc_rate_table *tab);
114 void qdisc_put_stab(struct qdisc_size_table *tab);
115 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
116 bool sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
117 		     struct net_device *dev, struct netdev_queue *txq,
118 		     spinlock_t *root_lock, bool validate);
119 
120 void __qdisc_run(struct Qdisc *q);
121 
122 static inline void qdisc_run(struct Qdisc *q)
123 {
124 	if (qdisc_run_begin(q)) {
125 		__qdisc_run(q);
126 		qdisc_run_end(q);
127 	}
128 }
129 
130 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
131 
132 /* Calculate maximal size of packet seen by hard_start_xmit
133    routine of this device.
134  */
135 static inline unsigned int psched_mtu(const struct net_device *dev)
136 {
137 	return READ_ONCE(dev->mtu) + dev->hard_header_len;
138 }
139 
140 static inline struct net *qdisc_net(struct Qdisc *q)
141 {
142 	return dev_net(q->dev_queue->dev);
143 }
144 
145 struct tc_query_caps_base {
146 	enum tc_setup_type type;
147 	void *caps;
148 };
149 
150 struct tc_cbs_qopt_offload {
151 	u8 enable;
152 	s32 queue;
153 	s32 hicredit;
154 	s32 locredit;
155 	s32 idleslope;
156 	s32 sendslope;
157 };
158 
159 struct tc_etf_qopt_offload {
160 	u8 enable;
161 	s32 queue;
162 };
163 
164 struct tc_mqprio_caps {
165 	bool validate_queue_counts:1;
166 };
167 
168 struct tc_mqprio_qopt_offload {
169 	/* struct tc_mqprio_qopt must always be the first element */
170 	struct tc_mqprio_qopt qopt;
171 	struct netlink_ext_ack *extack;
172 	u16 mode;
173 	u16 shaper;
174 	u32 flags;
175 	u64 min_rate[TC_QOPT_MAX_QUEUE];
176 	u64 max_rate[TC_QOPT_MAX_QUEUE];
177 	unsigned long preemptible_tcs;
178 };
179 
180 struct tc_taprio_caps {
181 	bool supports_queue_max_sdu:1;
182 	bool gate_mask_per_txq:1;
183 	/* Device expects lower TXQ numbers to have higher priority over higher
184 	 * TXQs, regardless of their TC mapping. DO NOT USE FOR NEW DRIVERS,
185 	 * INSTEAD ENFORCE A PROPER TC:TXQ MAPPING COMING FROM USER SPACE.
186 	 */
187 	bool broken_mqprio:1;
188 };
189 
190 enum tc_taprio_qopt_cmd {
191 	TAPRIO_CMD_REPLACE,
192 	TAPRIO_CMD_DESTROY,
193 	TAPRIO_CMD_STATS,
194 	TAPRIO_CMD_QUEUE_STATS,
195 };
196 
197 /**
198  * struct tc_taprio_qopt_stats - IEEE 802.1Qbv statistics
199  * @window_drops: Frames that were dropped because they were too large to be
200  *	transmitted in any of the allotted time windows (open gates) for their
201  *	traffic class.
202  * @tx_overruns: Frames still being transmitted by the MAC after the
203  *	transmission gate associated with their traffic class has closed.
204  *	Equivalent to `12.29.1.1.2 TransmissionOverrun` from 802.1Q-2018.
205  */
206 struct tc_taprio_qopt_stats {
207 	u64 window_drops;
208 	u64 tx_overruns;
209 };
210 
211 struct tc_taprio_qopt_queue_stats {
212 	int queue;
213 	struct tc_taprio_qopt_stats stats;
214 };
215 
216 struct tc_taprio_sched_entry {
217 	u8 command; /* TC_TAPRIO_CMD_* */
218 
219 	/* The gate_mask in the offloading side refers to traffic classes */
220 	u32 gate_mask;
221 	u32 interval;
222 };
223 
224 struct tc_taprio_qopt_offload {
225 	enum tc_taprio_qopt_cmd cmd;
226 
227 	union {
228 		/* TAPRIO_CMD_STATS */
229 		struct tc_taprio_qopt_stats stats;
230 		/* TAPRIO_CMD_QUEUE_STATS */
231 		struct tc_taprio_qopt_queue_stats queue_stats;
232 		/* TAPRIO_CMD_REPLACE */
233 		struct {
234 			struct tc_mqprio_qopt_offload mqprio;
235 			struct netlink_ext_ack *extack;
236 			ktime_t base_time;
237 			u64 cycle_time;
238 			u64 cycle_time_extension;
239 			u32 max_sdu[TC_MAX_QUEUE];
240 
241 			size_t num_entries;
242 			struct tc_taprio_sched_entry entries[];
243 		};
244 	};
245 };
246 
247 #if IS_ENABLED(CONFIG_NET_SCH_TAPRIO)
248 
249 /* Reference counting */
250 struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
251 						  *offload);
252 void taprio_offload_free(struct tc_taprio_qopt_offload *offload);
253 
254 #else
255 
256 /* Reference counting */
257 static inline struct tc_taprio_qopt_offload *
258 taprio_offload_get(struct tc_taprio_qopt_offload *offload)
259 {
260 	return NULL;
261 }
262 
263 static inline void taprio_offload_free(struct tc_taprio_qopt_offload *offload)
264 {
265 }
266 
267 #endif
268 
269 /* Ensure skb_mstamp_ns, which might have been populated with the txtime, is
270  * not mistaken for a software timestamp, because this will otherwise prevent
271  * the dispatch of hardware timestamps to the socket.
272  */
273 static inline void skb_txtime_consumed(struct sk_buff *skb)
274 {
275 	skb->tstamp = ktime_set(0, 0);
276 }
277 
278 struct tc_skb_cb {
279 	struct qdisc_skb_cb qdisc_cb;
280 
281 	u16 mru;
282 	u8 post_ct:1;
283 	u8 post_ct_snat:1;
284 	u8 post_ct_dnat:1;
285 	u16 zone; /* Only valid if post_ct = true */
286 };
287 
288 static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)
289 {
290 	struct tc_skb_cb *cb = (struct tc_skb_cb *)skb->cb;
291 
292 	BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));
293 	return cb;
294 }
295 
296 static inline bool tc_qdisc_stats_dump(struct Qdisc *sch,
297 				       unsigned long cl,
298 				       struct qdisc_walker *arg)
299 {
300 	if (arg->count >= arg->skip && arg->fn(sch, cl, arg) < 0) {
301 		arg->stop = 1;
302 		return false;
303 	}
304 
305 	arg->count++;
306 	return true;
307 }
308 
309 #endif
310