xref: /linux/include/net/sch_generic.h (revision a5d9265e017f081f0dc133c0e2f45103d027b874)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __NET_SCHED_GENERIC_H
3 #define __NET_SCHED_GENERIC_H
4 
5 #include <linux/netdevice.h>
6 #include <linux/types.h>
7 #include <linux/rcupdate.h>
8 #include <linux/pkt_sched.h>
9 #include <linux/pkt_cls.h>
10 #include <linux/percpu.h>
11 #include <linux/dynamic_queue_limits.h>
12 #include <linux/list.h>
13 #include <linux/refcount.h>
14 #include <linux/workqueue.h>
15 #include <linux/mutex.h>
16 #include <net/gen_stats.h>
17 #include <net/rtnetlink.h>
18 
19 struct Qdisc_ops;
20 struct qdisc_walker;
21 struct tcf_walker;
22 struct module;
23 struct bpf_flow_keys;
24 
25 typedef int tc_setup_cb_t(enum tc_setup_type type,
26 			  void *type_data, void *cb_priv);
27 
28 typedef int tc_indr_block_bind_cb_t(struct net_device *dev, void *cb_priv,
29 				    enum tc_setup_type type, void *type_data);
30 
31 struct qdisc_rate_table {
32 	struct tc_ratespec rate;
33 	u32		data[256];
34 	struct qdisc_rate_table *next;
35 	int		refcnt;
36 };
37 
38 enum qdisc_state_t {
39 	__QDISC_STATE_SCHED,
40 	__QDISC_STATE_DEACTIVATED,
41 };
42 
43 struct qdisc_size_table {
44 	struct rcu_head		rcu;
45 	struct list_head	list;
46 	struct tc_sizespec	szopts;
47 	int			refcnt;
48 	u16			data[];
49 };
50 
51 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
52 struct qdisc_skb_head {
53 	struct sk_buff	*head;
54 	struct sk_buff	*tail;
55 	__u32		qlen;
56 	spinlock_t	lock;
57 };
58 
59 struct Qdisc {
60 	int 			(*enqueue)(struct sk_buff *skb,
61 					   struct Qdisc *sch,
62 					   struct sk_buff **to_free);
63 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
64 	unsigned int		flags;
65 #define TCQ_F_BUILTIN		1
66 #define TCQ_F_INGRESS		2
67 #define TCQ_F_CAN_BYPASS	4
68 #define TCQ_F_MQROOT		8
69 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
70 				      * q->dev_queue : It can test
71 				      * netif_xmit_frozen_or_stopped() before
72 				      * dequeueing next packet.
73 				      * Its true for MQ/MQPRIO slaves, or non
74 				      * multiqueue device.
75 				      */
76 #define TCQ_F_WARN_NONWC	(1 << 16)
77 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
78 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
79 				      * qdisc_tree_decrease_qlen() should stop.
80 				      */
81 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
82 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
83 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
84 	u32			limit;
85 	const struct Qdisc_ops	*ops;
86 	struct qdisc_size_table	__rcu *stab;
87 	struct hlist_node       hash;
88 	u32			handle;
89 	u32			parent;
90 
91 	struct netdev_queue	*dev_queue;
92 
93 	struct net_rate_estimator __rcu *rate_est;
94 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
95 	struct gnet_stats_queue	__percpu *cpu_qstats;
96 	int			padded;
97 	refcount_t		refcnt;
98 
99 	/*
100 	 * For performance sake on SMP, we put highly modified fields at the end
101 	 */
102 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
103 	struct qdisc_skb_head	q;
104 	struct gnet_stats_basic_packed bstats;
105 	seqcount_t		running;
106 	struct gnet_stats_queue	qstats;
107 	unsigned long		state;
108 	struct Qdisc            *next_sched;
109 	struct sk_buff_head	skb_bad_txq;
110 
111 	spinlock_t		busylock ____cacheline_aligned_in_smp;
112 	spinlock_t		seqlock;
113 	struct rcu_head		rcu;
114 };
115 
116 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
117 {
118 	if (qdisc->flags & TCQ_F_BUILTIN)
119 		return;
120 	refcount_inc(&qdisc->refcnt);
121 }
122 
123 /* Intended to be used by unlocked users, when concurrent qdisc release is
124  * possible.
125  */
126 
127 static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
128 {
129 	if (qdisc->flags & TCQ_F_BUILTIN)
130 		return qdisc;
131 	if (refcount_inc_not_zero(&qdisc->refcnt))
132 		return qdisc;
133 	return NULL;
134 }
135 
136 static inline bool qdisc_is_running(struct Qdisc *qdisc)
137 {
138 	if (qdisc->flags & TCQ_F_NOLOCK)
139 		return spin_is_locked(&qdisc->seqlock);
140 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
141 }
142 
143 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
144 {
145 	if (qdisc->flags & TCQ_F_NOLOCK) {
146 		if (!spin_trylock(&qdisc->seqlock))
147 			return false;
148 	} else if (qdisc_is_running(qdisc)) {
149 		return false;
150 	}
151 	/* Variant of write_seqcount_begin() telling lockdep a trylock
152 	 * was attempted.
153 	 */
154 	raw_write_seqcount_begin(&qdisc->running);
155 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
156 	return true;
157 }
158 
159 static inline void qdisc_run_end(struct Qdisc *qdisc)
160 {
161 	write_seqcount_end(&qdisc->running);
162 	if (qdisc->flags & TCQ_F_NOLOCK)
163 		spin_unlock(&qdisc->seqlock);
164 }
165 
166 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
167 {
168 	return qdisc->flags & TCQ_F_ONETXQUEUE;
169 }
170 
171 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
172 {
173 #ifdef CONFIG_BQL
174 	/* Non-BQL migrated drivers will return 0, too. */
175 	return dql_avail(&txq->dql);
176 #else
177 	return 0;
178 #endif
179 }
180 
181 struct Qdisc_class_ops {
182 	unsigned int		flags;
183 	/* Child qdisc manipulation */
184 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
185 	int			(*graft)(struct Qdisc *, unsigned long cl,
186 					struct Qdisc *, struct Qdisc **,
187 					struct netlink_ext_ack *extack);
188 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
189 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
190 
191 	/* Class manipulation routines */
192 	unsigned long		(*find)(struct Qdisc *, u32 classid);
193 	int			(*change)(struct Qdisc *, u32, u32,
194 					struct nlattr **, unsigned long *,
195 					struct netlink_ext_ack *);
196 	int			(*delete)(struct Qdisc *, unsigned long);
197 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
198 
199 	/* Filter manipulation */
200 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
201 					     unsigned long arg,
202 					     struct netlink_ext_ack *extack);
203 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
204 					u32 classid);
205 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
206 
207 	/* rtnetlink specific */
208 	int			(*dump)(struct Qdisc *, unsigned long,
209 					struct sk_buff *skb, struct tcmsg*);
210 	int			(*dump_stats)(struct Qdisc *, unsigned long,
211 					struct gnet_dump *);
212 };
213 
214 /* Qdisc_class_ops flag values */
215 
216 /* Implements API that doesn't require rtnl lock */
217 enum qdisc_class_ops_flags {
218 	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
219 };
220 
221 struct Qdisc_ops {
222 	struct Qdisc_ops	*next;
223 	const struct Qdisc_class_ops	*cl_ops;
224 	char			id[IFNAMSIZ];
225 	int			priv_size;
226 	unsigned int		static_flags;
227 
228 	int 			(*enqueue)(struct sk_buff *skb,
229 					   struct Qdisc *sch,
230 					   struct sk_buff **to_free);
231 	struct sk_buff *	(*dequeue)(struct Qdisc *);
232 	struct sk_buff *	(*peek)(struct Qdisc *);
233 
234 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
235 					struct netlink_ext_ack *extack);
236 	void			(*reset)(struct Qdisc *);
237 	void			(*destroy)(struct Qdisc *);
238 	int			(*change)(struct Qdisc *sch,
239 					  struct nlattr *arg,
240 					  struct netlink_ext_ack *extack);
241 	void			(*attach)(struct Qdisc *sch);
242 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
243 
244 	int			(*dump)(struct Qdisc *, struct sk_buff *);
245 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
246 
247 	void			(*ingress_block_set)(struct Qdisc *sch,
248 						     u32 block_index);
249 	void			(*egress_block_set)(struct Qdisc *sch,
250 						    u32 block_index);
251 	u32			(*ingress_block_get)(struct Qdisc *sch);
252 	u32			(*egress_block_get)(struct Qdisc *sch);
253 
254 	struct module		*owner;
255 };
256 
257 
258 struct tcf_result {
259 	union {
260 		struct {
261 			unsigned long	class;
262 			u32		classid;
263 		};
264 		const struct tcf_proto *goto_tp;
265 
266 		/* used by the TC_ACT_REINSERT action */
267 		struct {
268 			bool		ingress;
269 			struct gnet_stats_queue *qstats;
270 		};
271 	};
272 };
273 
274 struct tcf_chain;
275 
276 struct tcf_proto_ops {
277 	struct list_head	head;
278 	char			kind[IFNAMSIZ];
279 
280 	int			(*classify)(struct sk_buff *,
281 					    const struct tcf_proto *,
282 					    struct tcf_result *);
283 	int			(*init)(struct tcf_proto*);
284 	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
285 					   struct netlink_ext_ack *extack);
286 
287 	void*			(*get)(struct tcf_proto*, u32 handle);
288 	void			(*put)(struct tcf_proto *tp, void *f);
289 	int			(*change)(struct net *net, struct sk_buff *,
290 					struct tcf_proto*, unsigned long,
291 					u32 handle, struct nlattr **,
292 					void **, bool, bool,
293 					struct netlink_ext_ack *);
294 	int			(*delete)(struct tcf_proto *tp, void *arg,
295 					  bool *last, bool rtnl_held,
296 					  struct netlink_ext_ack *);
297 	void			(*walk)(struct tcf_proto *tp,
298 					struct tcf_walker *arg, bool rtnl_held);
299 	int			(*reoffload)(struct tcf_proto *tp, bool add,
300 					     tc_setup_cb_t *cb, void *cb_priv,
301 					     struct netlink_ext_ack *extack);
302 	void			(*bind_class)(void *, u32, unsigned long);
303 	void *			(*tmplt_create)(struct net *net,
304 						struct tcf_chain *chain,
305 						struct nlattr **tca,
306 						struct netlink_ext_ack *extack);
307 	void			(*tmplt_destroy)(void *tmplt_priv);
308 
309 	/* rtnetlink specific */
310 	int			(*dump)(struct net*, struct tcf_proto*, void *,
311 					struct sk_buff *skb, struct tcmsg*,
312 					bool);
313 	int			(*tmplt_dump)(struct sk_buff *skb,
314 					      struct net *net,
315 					      void *tmplt_priv);
316 
317 	struct module		*owner;
318 	int			flags;
319 };
320 
321 enum tcf_proto_ops_flags {
322 	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
323 };
324 
325 struct tcf_proto {
326 	/* Fast access part */
327 	struct tcf_proto __rcu	*next;
328 	void __rcu		*root;
329 
330 	/* called under RCU BH lock*/
331 	int			(*classify)(struct sk_buff *,
332 					    const struct tcf_proto *,
333 					    struct tcf_result *);
334 	__be16			protocol;
335 
336 	/* All the rest */
337 	u32			prio;
338 	void			*data;
339 	const struct tcf_proto_ops	*ops;
340 	struct tcf_chain	*chain;
341 	/* Lock protects tcf_proto shared state and can be used by unlocked
342 	 * classifiers to protect their private data.
343 	 */
344 	spinlock_t		lock;
345 	bool			deleting;
346 	refcount_t		refcnt;
347 	struct rcu_head		rcu;
348 };
349 
350 struct qdisc_skb_cb {
351 	union {
352 		struct {
353 			unsigned int		pkt_len;
354 			u16			slave_dev_queue_mapping;
355 			u16			tc_classid;
356 		};
357 		struct bpf_flow_keys *flow_keys;
358 	};
359 #define QDISC_CB_PRIV_LEN 20
360 	unsigned char		data[QDISC_CB_PRIV_LEN];
361 };
362 
363 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
364 
365 struct tcf_chain {
366 	/* Protects filter_chain. */
367 	struct mutex filter_chain_lock;
368 	struct tcf_proto __rcu *filter_chain;
369 	struct list_head list;
370 	struct tcf_block *block;
371 	u32 index; /* chain index */
372 	unsigned int refcnt;
373 	unsigned int action_refcnt;
374 	bool explicitly_created;
375 	bool flushing;
376 	const struct tcf_proto_ops *tmplt_ops;
377 	void *tmplt_priv;
378 };
379 
380 struct tcf_block {
381 	/* Lock protects tcf_block and lifetime-management data of chains
382 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
383 	 */
384 	struct mutex lock;
385 	struct list_head chain_list;
386 	u32 index; /* block index for shared blocks */
387 	refcount_t refcnt;
388 	struct net *net;
389 	struct Qdisc *q;
390 	struct list_head cb_list;
391 	struct list_head owner_list;
392 	bool keep_dst;
393 	unsigned int offloadcnt; /* Number of oddloaded filters */
394 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
395 	struct {
396 		struct tcf_chain *chain;
397 		struct list_head filter_chain_list;
398 	} chain0;
399 	struct rcu_head rcu;
400 };
401 
402 #ifdef CONFIG_PROVE_LOCKING
403 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
404 {
405 	return lockdep_is_held(&chain->filter_chain_lock);
406 }
407 
408 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
409 {
410 	return lockdep_is_held(&tp->lock);
411 }
412 #else
413 static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
414 {
415 	return true;
416 }
417 
418 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
419 {
420 	return true;
421 }
422 #endif /* #ifdef CONFIG_PROVE_LOCKING */
423 
424 #define tcf_chain_dereference(p, chain)					\
425 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
426 
427 #define tcf_proto_dereference(p, tp)					\
428 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
429 
430 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
431 {
432 	if (*flags & TCA_CLS_FLAGS_IN_HW)
433 		return;
434 	*flags |= TCA_CLS_FLAGS_IN_HW;
435 	block->offloadcnt++;
436 }
437 
438 static inline void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
439 {
440 	if (!(*flags & TCA_CLS_FLAGS_IN_HW))
441 		return;
442 	*flags &= ~TCA_CLS_FLAGS_IN_HW;
443 	block->offloadcnt--;
444 }
445 
446 static inline void
447 tc_cls_offload_cnt_update(struct tcf_block *block, u32 *cnt,
448 			  u32 *flags, bool add)
449 {
450 	if (add) {
451 		if (!*cnt)
452 			tcf_block_offload_inc(block, flags);
453 		(*cnt)++;
454 	} else {
455 		(*cnt)--;
456 		if (!*cnt)
457 			tcf_block_offload_dec(block, flags);
458 	}
459 }
460 
461 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
462 {
463 	struct qdisc_skb_cb *qcb;
464 
465 	BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
466 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
467 }
468 
469 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
470 {
471 	return this_cpu_ptr(q->cpu_qstats)->qlen;
472 }
473 
474 static inline int qdisc_qlen(const struct Qdisc *q)
475 {
476 	return q->q.qlen;
477 }
478 
479 static inline int qdisc_qlen_sum(const struct Qdisc *q)
480 {
481 	__u32 qlen = q->qstats.qlen;
482 	int i;
483 
484 	if (q->flags & TCQ_F_NOLOCK) {
485 		for_each_possible_cpu(i)
486 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
487 	} else {
488 		qlen += q->q.qlen;
489 	}
490 
491 	return qlen;
492 }
493 
494 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
495 {
496 	return (struct qdisc_skb_cb *)skb->cb;
497 }
498 
499 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
500 {
501 	return &qdisc->q.lock;
502 }
503 
504 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
505 {
506 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
507 
508 	return q;
509 }
510 
511 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
512 {
513 	return qdisc->dev_queue->qdisc_sleeping;
514 }
515 
516 /* The qdisc root lock is a mechanism by which to top level
517  * of a qdisc tree can be locked from any qdisc node in the
518  * forest.  This allows changing the configuration of some
519  * aspect of the qdisc tree while blocking out asynchronous
520  * qdisc access in the packet processing paths.
521  *
522  * It is only legal to do this when the root will not change
523  * on us.  Otherwise we'll potentially lock the wrong qdisc
524  * root.  This is enforced by holding the RTNL semaphore, which
525  * all users of this lock accessor must do.
526  */
527 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
528 {
529 	struct Qdisc *root = qdisc_root(qdisc);
530 
531 	ASSERT_RTNL();
532 	return qdisc_lock(root);
533 }
534 
535 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
536 {
537 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
538 
539 	ASSERT_RTNL();
540 	return qdisc_lock(root);
541 }
542 
543 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
544 {
545 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
546 
547 	ASSERT_RTNL();
548 	return &root->running;
549 }
550 
551 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
552 {
553 	return qdisc->dev_queue->dev;
554 }
555 
556 static inline void sch_tree_lock(const struct Qdisc *q)
557 {
558 	spin_lock_bh(qdisc_root_sleeping_lock(q));
559 }
560 
561 static inline void sch_tree_unlock(const struct Qdisc *q)
562 {
563 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
564 }
565 
566 extern struct Qdisc noop_qdisc;
567 extern struct Qdisc_ops noop_qdisc_ops;
568 extern struct Qdisc_ops pfifo_fast_ops;
569 extern struct Qdisc_ops mq_qdisc_ops;
570 extern struct Qdisc_ops noqueue_qdisc_ops;
571 extern const struct Qdisc_ops *default_qdisc_ops;
572 static inline const struct Qdisc_ops *
573 get_default_qdisc_ops(const struct net_device *dev, int ntx)
574 {
575 	return ntx < dev->real_num_tx_queues ?
576 			default_qdisc_ops : &pfifo_fast_ops;
577 }
578 
579 struct Qdisc_class_common {
580 	u32			classid;
581 	struct hlist_node	hnode;
582 };
583 
584 struct Qdisc_class_hash {
585 	struct hlist_head	*hash;
586 	unsigned int		hashsize;
587 	unsigned int		hashmask;
588 	unsigned int		hashelems;
589 };
590 
591 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
592 {
593 	id ^= id >> 8;
594 	id ^= id >> 4;
595 	return id & mask;
596 }
597 
598 static inline struct Qdisc_class_common *
599 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
600 {
601 	struct Qdisc_class_common *cl;
602 	unsigned int h;
603 
604 	if (!id)
605 		return NULL;
606 
607 	h = qdisc_class_hash(id, hash->hashmask);
608 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
609 		if (cl->classid == id)
610 			return cl;
611 	}
612 	return NULL;
613 }
614 
615 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
616 {
617 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
618 
619 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
620 }
621 
622 int qdisc_class_hash_init(struct Qdisc_class_hash *);
623 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
624 			     struct Qdisc_class_common *);
625 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
626 			     struct Qdisc_class_common *);
627 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
628 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
629 
630 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
631 void dev_init_scheduler(struct net_device *dev);
632 void dev_shutdown(struct net_device *dev);
633 void dev_activate(struct net_device *dev);
634 void dev_deactivate(struct net_device *dev);
635 void dev_deactivate_many(struct list_head *head);
636 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
637 			      struct Qdisc *qdisc);
638 void qdisc_reset(struct Qdisc *qdisc);
639 void qdisc_put(struct Qdisc *qdisc);
640 void qdisc_put_unlocked(struct Qdisc *qdisc);
641 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
642 #ifdef CONFIG_NET_SCHED
643 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
644 			      void *type_data);
645 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
646 				struct Qdisc *new, struct Qdisc *old,
647 				enum tc_setup_type type, void *type_data,
648 				struct netlink_ext_ack *extack);
649 #else
650 static inline int
651 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
652 			  void *type_data)
653 {
654 	q->flags &= ~TCQ_F_OFFLOADED;
655 	return 0;
656 }
657 
658 static inline void
659 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
660 			   struct Qdisc *new, struct Qdisc *old,
661 			   enum tc_setup_type type, void *type_data,
662 			   struct netlink_ext_ack *extack)
663 {
664 }
665 #endif
666 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
667 			  const struct Qdisc_ops *ops,
668 			  struct netlink_ext_ack *extack);
669 void qdisc_free(struct Qdisc *qdisc);
670 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
671 				const struct Qdisc_ops *ops, u32 parentid,
672 				struct netlink_ext_ack *extack);
673 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
674 			       const struct qdisc_size_table *stab);
675 int skb_do_redirect(struct sk_buff *);
676 
677 static inline void skb_reset_tc(struct sk_buff *skb)
678 {
679 #ifdef CONFIG_NET_CLS_ACT
680 	skb->tc_redirected = 0;
681 #endif
682 }
683 
684 static inline bool skb_is_tc_redirected(const struct sk_buff *skb)
685 {
686 #ifdef CONFIG_NET_CLS_ACT
687 	return skb->tc_redirected;
688 #else
689 	return false;
690 #endif
691 }
692 
693 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
694 {
695 #ifdef CONFIG_NET_CLS_ACT
696 	return skb->tc_at_ingress;
697 #else
698 	return false;
699 #endif
700 }
701 
702 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
703 {
704 #ifdef CONFIG_NET_CLS_ACT
705 	if (skb->tc_skip_classify) {
706 		skb->tc_skip_classify = 0;
707 		return true;
708 	}
709 #endif
710 	return false;
711 }
712 
713 /* Reset all TX qdiscs greater than index of a device.  */
714 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
715 {
716 	struct Qdisc *qdisc;
717 
718 	for (; i < dev->num_tx_queues; i++) {
719 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
720 		if (qdisc) {
721 			spin_lock_bh(qdisc_lock(qdisc));
722 			qdisc_reset(qdisc);
723 			spin_unlock_bh(qdisc_lock(qdisc));
724 		}
725 	}
726 }
727 
728 static inline void qdisc_reset_all_tx(struct net_device *dev)
729 {
730 	qdisc_reset_all_tx_gt(dev, 0);
731 }
732 
733 /* Are all TX queues of the device empty?  */
734 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
735 {
736 	unsigned int i;
737 
738 	rcu_read_lock();
739 	for (i = 0; i < dev->num_tx_queues; i++) {
740 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
741 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
742 
743 		if (q->q.qlen) {
744 			rcu_read_unlock();
745 			return false;
746 		}
747 	}
748 	rcu_read_unlock();
749 	return true;
750 }
751 
752 /* Are any of the TX qdiscs changing?  */
753 static inline bool qdisc_tx_changing(const struct net_device *dev)
754 {
755 	unsigned int i;
756 
757 	for (i = 0; i < dev->num_tx_queues; i++) {
758 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
759 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
760 			return true;
761 	}
762 	return false;
763 }
764 
765 /* Is the device using the noop qdisc on all queues?  */
766 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
767 {
768 	unsigned int i;
769 
770 	for (i = 0; i < dev->num_tx_queues; i++) {
771 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
772 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
773 			return false;
774 	}
775 	return true;
776 }
777 
778 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
779 {
780 	return qdisc_skb_cb(skb)->pkt_len;
781 }
782 
783 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
784 enum net_xmit_qdisc_t {
785 	__NET_XMIT_STOLEN = 0x00010000,
786 	__NET_XMIT_BYPASS = 0x00020000,
787 };
788 
789 #ifdef CONFIG_NET_CLS_ACT
790 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
791 #else
792 #define net_xmit_drop_count(e)	(1)
793 #endif
794 
795 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
796 					   const struct Qdisc *sch)
797 {
798 #ifdef CONFIG_NET_SCHED
799 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
800 
801 	if (stab)
802 		__qdisc_calculate_pkt_len(skb, stab);
803 #endif
804 }
805 
806 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
807 				struct sk_buff **to_free)
808 {
809 	qdisc_calculate_pkt_len(skb, sch);
810 	return sch->enqueue(skb, sch, to_free);
811 }
812 
813 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
814 {
815 	return q->flags & TCQ_F_CPUSTATS;
816 }
817 
818 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
819 				  __u64 bytes, __u32 packets)
820 {
821 	bstats->bytes += bytes;
822 	bstats->packets += packets;
823 }
824 
825 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
826 				 const struct sk_buff *skb)
827 {
828 	_bstats_update(bstats,
829 		       qdisc_pkt_len(skb),
830 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
831 }
832 
833 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
834 				      __u64 bytes, __u32 packets)
835 {
836 	u64_stats_update_begin(&bstats->syncp);
837 	_bstats_update(&bstats->bstats, bytes, packets);
838 	u64_stats_update_end(&bstats->syncp);
839 }
840 
841 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
842 				     const struct sk_buff *skb)
843 {
844 	u64_stats_update_begin(&bstats->syncp);
845 	bstats_update(&bstats->bstats, skb);
846 	u64_stats_update_end(&bstats->syncp);
847 }
848 
849 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
850 					   const struct sk_buff *skb)
851 {
852 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
853 }
854 
855 static inline void qdisc_bstats_update(struct Qdisc *sch,
856 				       const struct sk_buff *skb)
857 {
858 	bstats_update(&sch->bstats, skb);
859 }
860 
861 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
862 					    const struct sk_buff *skb)
863 {
864 	sch->qstats.backlog -= qdisc_pkt_len(skb);
865 }
866 
867 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
868 						const struct sk_buff *skb)
869 {
870 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
871 }
872 
873 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
874 					    const struct sk_buff *skb)
875 {
876 	sch->qstats.backlog += qdisc_pkt_len(skb);
877 }
878 
879 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
880 						const struct sk_buff *skb)
881 {
882 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
883 }
884 
885 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
886 {
887 	this_cpu_inc(sch->cpu_qstats->qlen);
888 }
889 
890 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
891 {
892 	this_cpu_dec(sch->cpu_qstats->qlen);
893 }
894 
895 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
896 {
897 	this_cpu_inc(sch->cpu_qstats->requeues);
898 }
899 
900 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
901 {
902 	sch->qstats.drops += count;
903 }
904 
905 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
906 {
907 	qstats->drops++;
908 }
909 
910 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
911 {
912 	qstats->overlimits++;
913 }
914 
915 static inline void qdisc_qstats_drop(struct Qdisc *sch)
916 {
917 	qstats_drop_inc(&sch->qstats);
918 }
919 
920 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
921 {
922 	this_cpu_inc(sch->cpu_qstats->drops);
923 }
924 
925 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
926 {
927 	sch->qstats.overlimits++;
928 }
929 
930 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
931 {
932 	qh->head = NULL;
933 	qh->tail = NULL;
934 	qh->qlen = 0;
935 }
936 
937 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
938 					struct qdisc_skb_head *qh)
939 {
940 	struct sk_buff *last = qh->tail;
941 
942 	if (last) {
943 		skb->next = NULL;
944 		last->next = skb;
945 		qh->tail = skb;
946 	} else {
947 		qh->tail = skb;
948 		qh->head = skb;
949 	}
950 	qh->qlen++;
951 }
952 
953 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
954 {
955 	__qdisc_enqueue_tail(skb, &sch->q);
956 	qdisc_qstats_backlog_inc(sch, skb);
957 	return NET_XMIT_SUCCESS;
958 }
959 
960 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
961 					struct qdisc_skb_head *qh)
962 {
963 	skb->next = qh->head;
964 
965 	if (!qh->head)
966 		qh->tail = skb;
967 	qh->head = skb;
968 	qh->qlen++;
969 }
970 
971 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
972 {
973 	struct sk_buff *skb = qh->head;
974 
975 	if (likely(skb != NULL)) {
976 		qh->head = skb->next;
977 		qh->qlen--;
978 		if (qh->head == NULL)
979 			qh->tail = NULL;
980 		skb->next = NULL;
981 	}
982 
983 	return skb;
984 }
985 
986 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
987 {
988 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
989 
990 	if (likely(skb != NULL)) {
991 		qdisc_qstats_backlog_dec(sch, skb);
992 		qdisc_bstats_update(sch, skb);
993 	}
994 
995 	return skb;
996 }
997 
998 /* Instead of calling kfree_skb() while root qdisc lock is held,
999  * queue the skb for future freeing at end of __dev_xmit_skb()
1000  */
1001 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1002 {
1003 	skb->next = *to_free;
1004 	*to_free = skb;
1005 }
1006 
1007 static inline void __qdisc_drop_all(struct sk_buff *skb,
1008 				    struct sk_buff **to_free)
1009 {
1010 	if (skb->prev)
1011 		skb->prev->next = *to_free;
1012 	else
1013 		skb->next = *to_free;
1014 	*to_free = skb;
1015 }
1016 
1017 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1018 						   struct qdisc_skb_head *qh,
1019 						   struct sk_buff **to_free)
1020 {
1021 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1022 
1023 	if (likely(skb != NULL)) {
1024 		unsigned int len = qdisc_pkt_len(skb);
1025 
1026 		qdisc_qstats_backlog_dec(sch, skb);
1027 		__qdisc_drop(skb, to_free);
1028 		return len;
1029 	}
1030 
1031 	return 0;
1032 }
1033 
1034 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
1035 						 struct sk_buff **to_free)
1036 {
1037 	return __qdisc_queue_drop_head(sch, &sch->q, to_free);
1038 }
1039 
1040 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1041 {
1042 	const struct qdisc_skb_head *qh = &sch->q;
1043 
1044 	return qh->head;
1045 }
1046 
1047 /* generic pseudo peek method for non-work-conserving qdisc */
1048 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1049 {
1050 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1051 
1052 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1053 	if (!skb) {
1054 		skb = sch->dequeue(sch);
1055 
1056 		if (skb) {
1057 			__skb_queue_head(&sch->gso_skb, skb);
1058 			/* it's still part of the queue */
1059 			qdisc_qstats_backlog_inc(sch, skb);
1060 			sch->q.qlen++;
1061 		}
1062 	}
1063 
1064 	return skb;
1065 }
1066 
1067 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1068 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1069 {
1070 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1071 
1072 	if (skb) {
1073 		skb = __skb_dequeue(&sch->gso_skb);
1074 		qdisc_qstats_backlog_dec(sch, skb);
1075 		sch->q.qlen--;
1076 	} else {
1077 		skb = sch->dequeue(sch);
1078 	}
1079 
1080 	return skb;
1081 }
1082 
1083 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1084 {
1085 	/*
1086 	 * We do not know the backlog in bytes of this list, it
1087 	 * is up to the caller to correct it
1088 	 */
1089 	ASSERT_RTNL();
1090 	if (qh->qlen) {
1091 		rtnl_kfree_skbs(qh->head, qh->tail);
1092 
1093 		qh->head = NULL;
1094 		qh->tail = NULL;
1095 		qh->qlen = 0;
1096 	}
1097 }
1098 
1099 static inline void qdisc_reset_queue(struct Qdisc *sch)
1100 {
1101 	__qdisc_reset_queue(&sch->q);
1102 	sch->qstats.backlog = 0;
1103 }
1104 
1105 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1106 					  struct Qdisc **pold)
1107 {
1108 	struct Qdisc *old;
1109 
1110 	sch_tree_lock(sch);
1111 	old = *pold;
1112 	*pold = new;
1113 	if (old != NULL) {
1114 		unsigned int qlen = old->q.qlen;
1115 		unsigned int backlog = old->qstats.backlog;
1116 
1117 		qdisc_reset(old);
1118 		qdisc_tree_reduce_backlog(old, qlen, backlog);
1119 	}
1120 	sch_tree_unlock(sch);
1121 
1122 	return old;
1123 }
1124 
1125 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1126 {
1127 	rtnl_kfree_skbs(skb, skb);
1128 	qdisc_qstats_drop(sch);
1129 }
1130 
1131 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1132 				 struct sk_buff **to_free)
1133 {
1134 	__qdisc_drop(skb, to_free);
1135 	qdisc_qstats_cpu_drop(sch);
1136 
1137 	return NET_XMIT_DROP;
1138 }
1139 
1140 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1141 			     struct sk_buff **to_free)
1142 {
1143 	__qdisc_drop(skb, to_free);
1144 	qdisc_qstats_drop(sch);
1145 
1146 	return NET_XMIT_DROP;
1147 }
1148 
1149 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1150 				 struct sk_buff **to_free)
1151 {
1152 	__qdisc_drop_all(skb, to_free);
1153 	qdisc_qstats_drop(sch);
1154 
1155 	return NET_XMIT_DROP;
1156 }
1157 
1158 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1159    long it will take to send a packet given its size.
1160  */
1161 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1162 {
1163 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1164 	if (slot < 0)
1165 		slot = 0;
1166 	slot >>= rtab->rate.cell_log;
1167 	if (slot > 255)
1168 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1169 	return rtab->data[slot];
1170 }
1171 
1172 struct psched_ratecfg {
1173 	u64	rate_bytes_ps; /* bytes per second */
1174 	u32	mult;
1175 	u16	overhead;
1176 	u8	linklayer;
1177 	u8	shift;
1178 };
1179 
1180 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1181 				unsigned int len)
1182 {
1183 	len += r->overhead;
1184 
1185 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1186 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1187 
1188 	return ((u64)len * r->mult) >> r->shift;
1189 }
1190 
1191 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1192 			       const struct tc_ratespec *conf,
1193 			       u64 rate64);
1194 
1195 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1196 					  const struct psched_ratecfg *r)
1197 {
1198 	memset(res, 0, sizeof(*res));
1199 
1200 	/* legacy struct tc_ratespec has a 32bit @rate field
1201 	 * Qdisc using 64bit rate should add new attributes
1202 	 * in order to maintain compatibility.
1203 	 */
1204 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1205 
1206 	res->overhead = r->overhead;
1207 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1208 }
1209 
1210 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1211  * The fast path only needs to access filter list and to update stats
1212  */
1213 struct mini_Qdisc {
1214 	struct tcf_proto *filter_list;
1215 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1216 	struct gnet_stats_queue	__percpu *cpu_qstats;
1217 	struct rcu_head rcu;
1218 };
1219 
1220 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1221 						const struct sk_buff *skb)
1222 {
1223 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1224 }
1225 
1226 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1227 {
1228 	this_cpu_inc(miniq->cpu_qstats->drops);
1229 }
1230 
1231 struct mini_Qdisc_pair {
1232 	struct mini_Qdisc miniq1;
1233 	struct mini_Qdisc miniq2;
1234 	struct mini_Qdisc __rcu **p_miniq;
1235 };
1236 
1237 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1238 			  struct tcf_proto *tp_head);
1239 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1240 			  struct mini_Qdisc __rcu **p_miniq);
1241 
1242 static inline void skb_tc_reinsert(struct sk_buff *skb, struct tcf_result *res)
1243 {
1244 	struct gnet_stats_queue *stats = res->qstats;
1245 	int ret;
1246 
1247 	if (res->ingress)
1248 		ret = netif_receive_skb(skb);
1249 	else
1250 		ret = dev_queue_xmit(skb);
1251 	if (ret && stats)
1252 		qstats_overlimit_inc(res->qstats);
1253 }
1254 
1255 #endif
1256