xref: /openbmc/linux/include/net/sch_generic.h (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
1 #ifndef __NET_SCHED_GENERIC_H
2 #define __NET_SCHED_GENERIC_H
3 
4 #include <linux/netdevice.h>
5 #include <linux/types.h>
6 #include <linux/rcupdate.h>
7 #include <linux/module.h>
8 #include <linux/pkt_sched.h>
9 #include <linux/pkt_cls.h>
10 #include <net/gen_stats.h>
11 #include <net/rtnetlink.h>
12 
13 struct Qdisc_ops;
14 struct qdisc_walker;
15 struct tcf_walker;
16 struct module;
17 
18 struct qdisc_rate_table {
19 	struct tc_ratespec rate;
20 	u32		data[256];
21 	struct qdisc_rate_table *next;
22 	int		refcnt;
23 };
24 
25 enum qdisc_state_t {
26 	__QDISC_STATE_SCHED,
27 	__QDISC_STATE_DEACTIVATED,
28 };
29 
30 /*
31  * following bits are only changed while qdisc lock is held
32  */
33 enum qdisc___state_t {
34 	__QDISC___STATE_RUNNING,
35 };
36 
37 struct qdisc_size_table {
38 	struct list_head	list;
39 	struct tc_sizespec	szopts;
40 	int			refcnt;
41 	u16			data[];
42 };
43 
44 struct Qdisc {
45 	int 			(*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
46 	struct sk_buff *	(*dequeue)(struct Qdisc *dev);
47 	unsigned		flags;
48 #define TCQ_F_BUILTIN		1
49 #define TCQ_F_THROTTLED		2
50 #define TCQ_F_INGRESS		4
51 #define TCQ_F_CAN_BYPASS	8
52 #define TCQ_F_MQROOT		16
53 #define TCQ_F_WARN_NONWC	(1 << 16)
54 	int			padded;
55 	struct Qdisc_ops	*ops;
56 	struct qdisc_size_table	*stab;
57 	struct list_head	list;
58 	u32			handle;
59 	u32			parent;
60 	atomic_t		refcnt;
61 	struct gnet_stats_rate_est	rate_est;
62 	int			(*reshape_fail)(struct sk_buff *skb,
63 					struct Qdisc *q);
64 
65 	void			*u32_node;
66 
67 	/* This field is deprecated, but it is still used by CBQ
68 	 * and it will live until better solution will be invented.
69 	 */
70 	struct Qdisc		*__parent;
71 	struct netdev_queue	*dev_queue;
72 	struct Qdisc		*next_sched;
73 
74 	struct sk_buff		*gso_skb;
75 	/*
76 	 * For performance sake on SMP, we put highly modified fields at the end
77 	 */
78 	unsigned long		state;
79 	struct sk_buff_head	q;
80 	struct gnet_stats_basic_packed bstats;
81 	unsigned long		__state;
82 	struct gnet_stats_queue	qstats;
83 	struct rcu_head		rcu_head;
84 	spinlock_t		busylock;
85 };
86 
87 static inline bool qdisc_is_running(struct Qdisc *qdisc)
88 {
89 	return test_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
90 }
91 
92 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
93 {
94 	return !__test_and_set_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
95 }
96 
97 static inline void qdisc_run_end(struct Qdisc *qdisc)
98 {
99 	__clear_bit(__QDISC___STATE_RUNNING, &qdisc->__state);
100 }
101 
102 struct Qdisc_class_ops {
103 	/* Child qdisc manipulation */
104 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
105 	int			(*graft)(struct Qdisc *, unsigned long cl,
106 					struct Qdisc *, struct Qdisc **);
107 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
108 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
109 
110 	/* Class manipulation routines */
111 	unsigned long		(*get)(struct Qdisc *, u32 classid);
112 	void			(*put)(struct Qdisc *, unsigned long);
113 	int			(*change)(struct Qdisc *, u32, u32,
114 					struct nlattr **, unsigned long *);
115 	int			(*delete)(struct Qdisc *, unsigned long);
116 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
117 
118 	/* Filter manipulation */
119 	struct tcf_proto **	(*tcf_chain)(struct Qdisc *, unsigned long);
120 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
121 					u32 classid);
122 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
123 
124 	/* rtnetlink specific */
125 	int			(*dump)(struct Qdisc *, unsigned long,
126 					struct sk_buff *skb, struct tcmsg*);
127 	int			(*dump_stats)(struct Qdisc *, unsigned long,
128 					struct gnet_dump *);
129 };
130 
131 struct Qdisc_ops {
132 	struct Qdisc_ops	*next;
133 	const struct Qdisc_class_ops	*cl_ops;
134 	char			id[IFNAMSIZ];
135 	int			priv_size;
136 
137 	int 			(*enqueue)(struct sk_buff *, struct Qdisc *);
138 	struct sk_buff *	(*dequeue)(struct Qdisc *);
139 	struct sk_buff *	(*peek)(struct Qdisc *);
140 	unsigned int		(*drop)(struct Qdisc *);
141 
142 	int			(*init)(struct Qdisc *, struct nlattr *arg);
143 	void			(*reset)(struct Qdisc *);
144 	void			(*destroy)(struct Qdisc *);
145 	int			(*change)(struct Qdisc *, struct nlattr *arg);
146 	void			(*attach)(struct Qdisc *);
147 
148 	int			(*dump)(struct Qdisc *, struct sk_buff *);
149 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
150 
151 	struct module		*owner;
152 };
153 
154 
155 struct tcf_result {
156 	unsigned long	class;
157 	u32		classid;
158 };
159 
160 struct tcf_proto_ops {
161 	struct tcf_proto_ops	*next;
162 	char			kind[IFNAMSIZ];
163 
164 	int			(*classify)(struct sk_buff*, struct tcf_proto*,
165 					struct tcf_result *);
166 	int			(*init)(struct tcf_proto*);
167 	void			(*destroy)(struct tcf_proto*);
168 
169 	unsigned long		(*get)(struct tcf_proto*, u32 handle);
170 	void			(*put)(struct tcf_proto*, unsigned long);
171 	int			(*change)(struct tcf_proto*, unsigned long,
172 					u32 handle, struct nlattr **,
173 					unsigned long *);
174 	int			(*delete)(struct tcf_proto*, unsigned long);
175 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
176 
177 	/* rtnetlink specific */
178 	int			(*dump)(struct tcf_proto*, unsigned long,
179 					struct sk_buff *skb, struct tcmsg*);
180 
181 	struct module		*owner;
182 };
183 
184 struct tcf_proto {
185 	/* Fast access part */
186 	struct tcf_proto	*next;
187 	void			*root;
188 	int			(*classify)(struct sk_buff*, struct tcf_proto*,
189 					struct tcf_result *);
190 	__be16			protocol;
191 
192 	/* All the rest */
193 	u32			prio;
194 	u32			classid;
195 	struct Qdisc		*q;
196 	void			*data;
197 	struct tcf_proto_ops	*ops;
198 };
199 
200 struct qdisc_skb_cb {
201 	unsigned int		pkt_len;
202 	char			data[];
203 };
204 
205 static inline int qdisc_qlen(struct Qdisc *q)
206 {
207 	return q->q.qlen;
208 }
209 
210 static inline struct qdisc_skb_cb *qdisc_skb_cb(struct sk_buff *skb)
211 {
212 	return (struct qdisc_skb_cb *)skb->cb;
213 }
214 
215 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
216 {
217 	return &qdisc->q.lock;
218 }
219 
220 static inline struct Qdisc *qdisc_root(struct Qdisc *qdisc)
221 {
222 	return qdisc->dev_queue->qdisc;
223 }
224 
225 static inline struct Qdisc *qdisc_root_sleeping(struct Qdisc *qdisc)
226 {
227 	return qdisc->dev_queue->qdisc_sleeping;
228 }
229 
230 /* The qdisc root lock is a mechanism by which to top level
231  * of a qdisc tree can be locked from any qdisc node in the
232  * forest.  This allows changing the configuration of some
233  * aspect of the qdisc tree while blocking out asynchronous
234  * qdisc access in the packet processing paths.
235  *
236  * It is only legal to do this when the root will not change
237  * on us.  Otherwise we'll potentially lock the wrong qdisc
238  * root.  This is enforced by holding the RTNL semaphore, which
239  * all users of this lock accessor must do.
240  */
241 static inline spinlock_t *qdisc_root_lock(struct Qdisc *qdisc)
242 {
243 	struct Qdisc *root = qdisc_root(qdisc);
244 
245 	ASSERT_RTNL();
246 	return qdisc_lock(root);
247 }
248 
249 static inline spinlock_t *qdisc_root_sleeping_lock(struct Qdisc *qdisc)
250 {
251 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
252 
253 	ASSERT_RTNL();
254 	return qdisc_lock(root);
255 }
256 
257 static inline struct net_device *qdisc_dev(struct Qdisc *qdisc)
258 {
259 	return qdisc->dev_queue->dev;
260 }
261 
262 static inline void sch_tree_lock(struct Qdisc *q)
263 {
264 	spin_lock_bh(qdisc_root_sleeping_lock(q));
265 }
266 
267 static inline void sch_tree_unlock(struct Qdisc *q)
268 {
269 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
270 }
271 
272 #define tcf_tree_lock(tp)	sch_tree_lock((tp)->q)
273 #define tcf_tree_unlock(tp)	sch_tree_unlock((tp)->q)
274 
275 extern struct Qdisc noop_qdisc;
276 extern struct Qdisc_ops noop_qdisc_ops;
277 extern struct Qdisc_ops pfifo_fast_ops;
278 extern struct Qdisc_ops mq_qdisc_ops;
279 
280 struct Qdisc_class_common {
281 	u32			classid;
282 	struct hlist_node	hnode;
283 };
284 
285 struct Qdisc_class_hash {
286 	struct hlist_head	*hash;
287 	unsigned int		hashsize;
288 	unsigned int		hashmask;
289 	unsigned int		hashelems;
290 };
291 
292 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
293 {
294 	id ^= id >> 8;
295 	id ^= id >> 4;
296 	return id & mask;
297 }
298 
299 static inline struct Qdisc_class_common *
300 qdisc_class_find(struct Qdisc_class_hash *hash, u32 id)
301 {
302 	struct Qdisc_class_common *cl;
303 	struct hlist_node *n;
304 	unsigned int h;
305 
306 	h = qdisc_class_hash(id, hash->hashmask);
307 	hlist_for_each_entry(cl, n, &hash->hash[h], hnode) {
308 		if (cl->classid == id)
309 			return cl;
310 	}
311 	return NULL;
312 }
313 
314 extern int qdisc_class_hash_init(struct Qdisc_class_hash *);
315 extern void qdisc_class_hash_insert(struct Qdisc_class_hash *, struct Qdisc_class_common *);
316 extern void qdisc_class_hash_remove(struct Qdisc_class_hash *, struct Qdisc_class_common *);
317 extern void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
318 extern void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
319 
320 extern void dev_init_scheduler(struct net_device *dev);
321 extern void dev_shutdown(struct net_device *dev);
322 extern void dev_activate(struct net_device *dev);
323 extern void dev_deactivate(struct net_device *dev);
324 extern void dev_deactivate_many(struct list_head *head);
325 extern struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
326 				     struct Qdisc *qdisc);
327 extern void qdisc_reset(struct Qdisc *qdisc);
328 extern void qdisc_destroy(struct Qdisc *qdisc);
329 extern void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
330 extern struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
331 				 struct Qdisc_ops *ops);
332 extern struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
333 				       struct Qdisc_ops *ops, u32 parentid);
334 extern void qdisc_calculate_pkt_len(struct sk_buff *skb,
335 				   struct qdisc_size_table *stab);
336 extern void tcf_destroy(struct tcf_proto *tp);
337 extern void tcf_destroy_chain(struct tcf_proto **fl);
338 
339 /* Reset all TX qdiscs greater then index of a device.  */
340 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
341 {
342 	struct Qdisc *qdisc;
343 
344 	for (; i < dev->num_tx_queues; i++) {
345 		qdisc = netdev_get_tx_queue(dev, i)->qdisc;
346 		if (qdisc) {
347 			spin_lock_bh(qdisc_lock(qdisc));
348 			qdisc_reset(qdisc);
349 			spin_unlock_bh(qdisc_lock(qdisc));
350 		}
351 	}
352 }
353 
354 static inline void qdisc_reset_all_tx(struct net_device *dev)
355 {
356 	qdisc_reset_all_tx_gt(dev, 0);
357 }
358 
359 /* Are all TX queues of the device empty?  */
360 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
361 {
362 	unsigned int i;
363 	for (i = 0; i < dev->num_tx_queues; i++) {
364 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
365 		const struct Qdisc *q = txq->qdisc;
366 
367 		if (q->q.qlen)
368 			return false;
369 	}
370 	return true;
371 }
372 
373 /* Are any of the TX qdiscs changing?  */
374 static inline bool qdisc_tx_changing(struct net_device *dev)
375 {
376 	unsigned int i;
377 	for (i = 0; i < dev->num_tx_queues; i++) {
378 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
379 		if (txq->qdisc != txq->qdisc_sleeping)
380 			return true;
381 	}
382 	return false;
383 }
384 
385 /* Is the device using the noop qdisc on all queues?  */
386 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
387 {
388 	unsigned int i;
389 	for (i = 0; i < dev->num_tx_queues; i++) {
390 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
391 		if (txq->qdisc != &noop_qdisc)
392 			return false;
393 	}
394 	return true;
395 }
396 
397 static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
398 {
399 	return qdisc_skb_cb(skb)->pkt_len;
400 }
401 
402 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
403 enum net_xmit_qdisc_t {
404 	__NET_XMIT_STOLEN = 0x00010000,
405 	__NET_XMIT_BYPASS = 0x00020000,
406 };
407 
408 #ifdef CONFIG_NET_CLS_ACT
409 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
410 #else
411 #define net_xmit_drop_count(e)	(1)
412 #endif
413 
414 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
415 {
416 #ifdef CONFIG_NET_SCHED
417 	if (sch->stab)
418 		qdisc_calculate_pkt_len(skb, sch->stab);
419 #endif
420 	return sch->enqueue(skb, sch);
421 }
422 
423 static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
424 {
425 	qdisc_skb_cb(skb)->pkt_len = skb->len;
426 	return qdisc_enqueue(skb, sch) & NET_XMIT_MASK;
427 }
428 
429 static inline void __qdisc_update_bstats(struct Qdisc *sch, unsigned int len)
430 {
431 	sch->bstats.bytes += len;
432 	sch->bstats.packets++;
433 }
434 
435 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
436 				       struct sk_buff_head *list)
437 {
438 	__skb_queue_tail(list, skb);
439 	sch->qstats.backlog += qdisc_pkt_len(skb);
440 	__qdisc_update_bstats(sch, qdisc_pkt_len(skb));
441 
442 	return NET_XMIT_SUCCESS;
443 }
444 
445 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
446 {
447 	return __qdisc_enqueue_tail(skb, sch, &sch->q);
448 }
449 
450 static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
451 						   struct sk_buff_head *list)
452 {
453 	struct sk_buff *skb = __skb_dequeue(list);
454 
455 	if (likely(skb != NULL))
456 		sch->qstats.backlog -= qdisc_pkt_len(skb);
457 
458 	return skb;
459 }
460 
461 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
462 {
463 	return __qdisc_dequeue_head(sch, &sch->q);
464 }
465 
466 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
467 					      struct sk_buff_head *list)
468 {
469 	struct sk_buff *skb = __qdisc_dequeue_head(sch, list);
470 
471 	if (likely(skb != NULL)) {
472 		unsigned int len = qdisc_pkt_len(skb);
473 		kfree_skb(skb);
474 		return len;
475 	}
476 
477 	return 0;
478 }
479 
480 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
481 {
482 	return __qdisc_queue_drop_head(sch, &sch->q);
483 }
484 
485 static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
486 						   struct sk_buff_head *list)
487 {
488 	struct sk_buff *skb = __skb_dequeue_tail(list);
489 
490 	if (likely(skb != NULL))
491 		sch->qstats.backlog -= qdisc_pkt_len(skb);
492 
493 	return skb;
494 }
495 
496 static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
497 {
498 	return __qdisc_dequeue_tail(sch, &sch->q);
499 }
500 
501 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
502 {
503 	return skb_peek(&sch->q);
504 }
505 
506 /* generic pseudo peek method for non-work-conserving qdisc */
507 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
508 {
509 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
510 	if (!sch->gso_skb) {
511 		sch->gso_skb = sch->dequeue(sch);
512 		if (sch->gso_skb)
513 			/* it's still part of the queue */
514 			sch->q.qlen++;
515 	}
516 
517 	return sch->gso_skb;
518 }
519 
520 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
521 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
522 {
523 	struct sk_buff *skb = sch->gso_skb;
524 
525 	if (skb) {
526 		sch->gso_skb = NULL;
527 		sch->q.qlen--;
528 	} else {
529 		skb = sch->dequeue(sch);
530 	}
531 
532 	return skb;
533 }
534 
535 static inline void __qdisc_reset_queue(struct Qdisc *sch,
536 				       struct sk_buff_head *list)
537 {
538 	/*
539 	 * We do not know the backlog in bytes of this list, it
540 	 * is up to the caller to correct it
541 	 */
542 	__skb_queue_purge(list);
543 }
544 
545 static inline void qdisc_reset_queue(struct Qdisc *sch)
546 {
547 	__qdisc_reset_queue(sch, &sch->q);
548 	sch->qstats.backlog = 0;
549 }
550 
551 static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
552 					      struct sk_buff_head *list)
553 {
554 	struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
555 
556 	if (likely(skb != NULL)) {
557 		unsigned int len = qdisc_pkt_len(skb);
558 		kfree_skb(skb);
559 		return len;
560 	}
561 
562 	return 0;
563 }
564 
565 static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
566 {
567 	return __qdisc_queue_drop(sch, &sch->q);
568 }
569 
570 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
571 {
572 	kfree_skb(skb);
573 	sch->qstats.drops++;
574 
575 	return NET_XMIT_DROP;
576 }
577 
578 static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
579 {
580 	sch->qstats.drops++;
581 
582 #ifdef CONFIG_NET_CLS_ACT
583 	if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
584 		goto drop;
585 
586 	return NET_XMIT_SUCCESS;
587 
588 drop:
589 #endif
590 	kfree_skb(skb);
591 	return NET_XMIT_DROP;
592 }
593 
594 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
595    long it will take to send a packet given its size.
596  */
597 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
598 {
599 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
600 	if (slot < 0)
601 		slot = 0;
602 	slot >>= rtab->rate.cell_log;
603 	if (slot > 255)
604 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
605 	return rtab->data[slot];
606 }
607 
608 #ifdef CONFIG_NET_CLS_ACT
609 static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask,
610 					    int action)
611 {
612 	struct sk_buff *n;
613 
614 	n = skb_clone(skb, gfp_mask);
615 
616 	if (n) {
617 		n->tc_verd = SET_TC_VERD(n->tc_verd, 0);
618 		n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
619 		n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
620 	}
621 	return n;
622 }
623 #endif
624 
625 #endif
626