xref: /openbmc/linux/include/net/sch_generic.h (revision a1515ec7)
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 <linux/rwsem.h>
17 #include <linux/atomic.h>
18 #include <linux/hashtable.h>
19 #include <net/gen_stats.h>
20 #include <net/rtnetlink.h>
21 #include <net/flow_offload.h>
22 
23 struct Qdisc_ops;
24 struct qdisc_walker;
25 struct tcf_walker;
26 struct module;
27 struct bpf_flow_keys;
28 
29 struct qdisc_rate_table {
30 	struct tc_ratespec rate;
31 	u32		data[256];
32 	struct qdisc_rate_table *next;
33 	int		refcnt;
34 };
35 
36 enum qdisc_state_t {
37 	__QDISC_STATE_SCHED,
38 	__QDISC_STATE_DEACTIVATED,
39 };
40 
41 struct qdisc_size_table {
42 	struct rcu_head		rcu;
43 	struct list_head	list;
44 	struct tc_sizespec	szopts;
45 	int			refcnt;
46 	u16			data[];
47 };
48 
49 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
50 struct qdisc_skb_head {
51 	struct sk_buff	*head;
52 	struct sk_buff	*tail;
53 	__u32		qlen;
54 	spinlock_t	lock;
55 };
56 
57 struct Qdisc {
58 	int 			(*enqueue)(struct sk_buff *skb,
59 					   struct Qdisc *sch,
60 					   struct sk_buff **to_free);
61 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
62 	unsigned int		flags;
63 #define TCQ_F_BUILTIN		1
64 #define TCQ_F_INGRESS		2
65 #define TCQ_F_CAN_BYPASS	4
66 #define TCQ_F_MQROOT		8
67 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
68 				      * q->dev_queue : It can test
69 				      * netif_xmit_frozen_or_stopped() before
70 				      * dequeueing next packet.
71 				      * Its true for MQ/MQPRIO slaves, or non
72 				      * multiqueue device.
73 				      */
74 #define TCQ_F_WARN_NONWC	(1 << 16)
75 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
76 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
77 				      * qdisc_tree_decrease_qlen() should stop.
78 				      */
79 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
80 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
81 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
82 	u32			limit;
83 	const struct Qdisc_ops	*ops;
84 	struct qdisc_size_table	__rcu *stab;
85 	struct hlist_node       hash;
86 	u32			handle;
87 	u32			parent;
88 
89 	struct netdev_queue	*dev_queue;
90 
91 	struct net_rate_estimator __rcu *rate_est;
92 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
93 	struct gnet_stats_queue	__percpu *cpu_qstats;
94 	int			pad;
95 	refcount_t		refcnt;
96 
97 	/*
98 	 * For performance sake on SMP, we put highly modified fields at the end
99 	 */
100 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
101 	struct qdisc_skb_head	q;
102 	struct gnet_stats_basic_packed bstats;
103 	seqcount_t		running;
104 	struct gnet_stats_queue	qstats;
105 	unsigned long		state;
106 	struct Qdisc            *next_sched;
107 	struct sk_buff_head	skb_bad_txq;
108 
109 	spinlock_t		busylock ____cacheline_aligned_in_smp;
110 	spinlock_t		seqlock;
111 
112 	/* for NOLOCK qdisc, true if there are no enqueued skbs */
113 	bool			empty;
114 	struct rcu_head		rcu;
115 
116 	/* private data */
117 	long privdata[] ____cacheline_aligned;
118 };
119 
120 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
121 {
122 	if (qdisc->flags & TCQ_F_BUILTIN)
123 		return;
124 	refcount_inc(&qdisc->refcnt);
125 }
126 
127 /* Intended to be used by unlocked users, when concurrent qdisc release is
128  * possible.
129  */
130 
131 static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
132 {
133 	if (qdisc->flags & TCQ_F_BUILTIN)
134 		return qdisc;
135 	if (refcount_inc_not_zero(&qdisc->refcnt))
136 		return qdisc;
137 	return NULL;
138 }
139 
140 static inline bool qdisc_is_running(struct Qdisc *qdisc)
141 {
142 	if (qdisc->flags & TCQ_F_NOLOCK)
143 		return spin_is_locked(&qdisc->seqlock);
144 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
145 }
146 
147 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
148 {
149 	return q->flags & TCQ_F_CPUSTATS;
150 }
151 
152 static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
153 {
154 	if (qdisc_is_percpu_stats(qdisc))
155 		return READ_ONCE(qdisc->empty);
156 	return !READ_ONCE(qdisc->q.qlen);
157 }
158 
159 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
160 {
161 	if (qdisc->flags & TCQ_F_NOLOCK) {
162 		if (!spin_trylock(&qdisc->seqlock))
163 			return false;
164 		WRITE_ONCE(qdisc->empty, false);
165 	} else if (qdisc_is_running(qdisc)) {
166 		return false;
167 	}
168 	/* Variant of write_seqcount_begin() telling lockdep a trylock
169 	 * was attempted.
170 	 */
171 	raw_write_seqcount_begin(&qdisc->running);
172 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
173 	return true;
174 }
175 
176 static inline void qdisc_run_end(struct Qdisc *qdisc)
177 {
178 	write_seqcount_end(&qdisc->running);
179 	if (qdisc->flags & TCQ_F_NOLOCK)
180 		spin_unlock(&qdisc->seqlock);
181 }
182 
183 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
184 {
185 	return qdisc->flags & TCQ_F_ONETXQUEUE;
186 }
187 
188 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
189 {
190 #ifdef CONFIG_BQL
191 	/* Non-BQL migrated drivers will return 0, too. */
192 	return dql_avail(&txq->dql);
193 #else
194 	return 0;
195 #endif
196 }
197 
198 struct Qdisc_class_ops {
199 	unsigned int		flags;
200 	/* Child qdisc manipulation */
201 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
202 	int			(*graft)(struct Qdisc *, unsigned long cl,
203 					struct Qdisc *, struct Qdisc **,
204 					struct netlink_ext_ack *extack);
205 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
206 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
207 
208 	/* Class manipulation routines */
209 	unsigned long		(*find)(struct Qdisc *, u32 classid);
210 	int			(*change)(struct Qdisc *, u32, u32,
211 					struct nlattr **, unsigned long *,
212 					struct netlink_ext_ack *);
213 	int			(*delete)(struct Qdisc *, unsigned long,
214 					  struct netlink_ext_ack *);
215 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
216 
217 	/* Filter manipulation */
218 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
219 					     unsigned long arg,
220 					     struct netlink_ext_ack *extack);
221 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
222 					u32 classid);
223 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
224 
225 	/* rtnetlink specific */
226 	int			(*dump)(struct Qdisc *, unsigned long,
227 					struct sk_buff *skb, struct tcmsg*);
228 	int			(*dump_stats)(struct Qdisc *, unsigned long,
229 					struct gnet_dump *);
230 };
231 
232 /* Qdisc_class_ops flag values */
233 
234 /* Implements API that doesn't require rtnl lock */
235 enum qdisc_class_ops_flags {
236 	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
237 };
238 
239 struct Qdisc_ops {
240 	struct Qdisc_ops	*next;
241 	const struct Qdisc_class_ops	*cl_ops;
242 	char			id[IFNAMSIZ];
243 	int			priv_size;
244 	unsigned int		static_flags;
245 
246 	int 			(*enqueue)(struct sk_buff *skb,
247 					   struct Qdisc *sch,
248 					   struct sk_buff **to_free);
249 	struct sk_buff *	(*dequeue)(struct Qdisc *);
250 	struct sk_buff *	(*peek)(struct Qdisc *);
251 
252 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
253 					struct netlink_ext_ack *extack);
254 	void			(*reset)(struct Qdisc *);
255 	void			(*destroy)(struct Qdisc *);
256 	int			(*change)(struct Qdisc *sch,
257 					  struct nlattr *arg,
258 					  struct netlink_ext_ack *extack);
259 	void			(*attach)(struct Qdisc *sch);
260 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
261 
262 	int			(*dump)(struct Qdisc *, struct sk_buff *);
263 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
264 
265 	void			(*ingress_block_set)(struct Qdisc *sch,
266 						     u32 block_index);
267 	void			(*egress_block_set)(struct Qdisc *sch,
268 						    u32 block_index);
269 	u32			(*ingress_block_get)(struct Qdisc *sch);
270 	u32			(*egress_block_get)(struct Qdisc *sch);
271 
272 	struct module		*owner;
273 };
274 
275 
276 struct tcf_result {
277 	union {
278 		struct {
279 			unsigned long	class;
280 			u32		classid;
281 		};
282 		const struct tcf_proto *goto_tp;
283 
284 		/* used in the skb_tc_reinsert function */
285 		struct {
286 			bool		ingress;
287 			struct gnet_stats_queue *qstats;
288 		};
289 	};
290 };
291 
292 struct tcf_chain;
293 
294 struct tcf_proto_ops {
295 	struct list_head	head;
296 	char			kind[IFNAMSIZ];
297 
298 	int			(*classify)(struct sk_buff *,
299 					    const struct tcf_proto *,
300 					    struct tcf_result *);
301 	int			(*init)(struct tcf_proto*);
302 	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
303 					   struct netlink_ext_ack *extack);
304 
305 	void*			(*get)(struct tcf_proto*, u32 handle);
306 	void			(*put)(struct tcf_proto *tp, void *f);
307 	int			(*change)(struct net *net, struct sk_buff *,
308 					struct tcf_proto*, unsigned long,
309 					u32 handle, struct nlattr **,
310 					void **, bool, bool,
311 					struct netlink_ext_ack *);
312 	int			(*delete)(struct tcf_proto *tp, void *arg,
313 					  bool *last, bool rtnl_held,
314 					  struct netlink_ext_ack *);
315 	bool			(*delete_empty)(struct tcf_proto *tp);
316 	void			(*walk)(struct tcf_proto *tp,
317 					struct tcf_walker *arg, bool rtnl_held);
318 	int			(*reoffload)(struct tcf_proto *tp, bool add,
319 					     flow_setup_cb_t *cb, void *cb_priv,
320 					     struct netlink_ext_ack *extack);
321 	void			(*hw_add)(struct tcf_proto *tp,
322 					  void *type_data);
323 	void			(*hw_del)(struct tcf_proto *tp,
324 					  void *type_data);
325 	void			(*bind_class)(void *, u32, unsigned long,
326 					      void *, unsigned long);
327 	void *			(*tmplt_create)(struct net *net,
328 						struct tcf_chain *chain,
329 						struct nlattr **tca,
330 						struct netlink_ext_ack *extack);
331 	void			(*tmplt_destroy)(void *tmplt_priv);
332 
333 	/* rtnetlink specific */
334 	int			(*dump)(struct net*, struct tcf_proto*, void *,
335 					struct sk_buff *skb, struct tcmsg*,
336 					bool);
337 	int			(*terse_dump)(struct net *net,
338 					      struct tcf_proto *tp, void *fh,
339 					      struct sk_buff *skb,
340 					      struct tcmsg *t, bool rtnl_held);
341 	int			(*tmplt_dump)(struct sk_buff *skb,
342 					      struct net *net,
343 					      void *tmplt_priv);
344 
345 	struct module		*owner;
346 	int			flags;
347 };
348 
349 /* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
350  * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
351  * conditions can occur when filters are inserted/deleted simultaneously.
352  */
353 enum tcf_proto_ops_flags {
354 	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
355 };
356 
357 struct tcf_proto {
358 	/* Fast access part */
359 	struct tcf_proto __rcu	*next;
360 	void __rcu		*root;
361 
362 	/* called under RCU BH lock*/
363 	int			(*classify)(struct sk_buff *,
364 					    const struct tcf_proto *,
365 					    struct tcf_result *);
366 	__be16			protocol;
367 
368 	/* All the rest */
369 	u32			prio;
370 	void			*data;
371 	const struct tcf_proto_ops	*ops;
372 	struct tcf_chain	*chain;
373 	/* Lock protects tcf_proto shared state and can be used by unlocked
374 	 * classifiers to protect their private data.
375 	 */
376 	spinlock_t		lock;
377 	bool			deleting;
378 	refcount_t		refcnt;
379 	struct rcu_head		rcu;
380 	struct hlist_node	destroy_ht_node;
381 };
382 
383 struct qdisc_skb_cb {
384 	struct {
385 		unsigned int		pkt_len;
386 		u16			slave_dev_queue_mapping;
387 		u16			tc_classid;
388 	};
389 #define QDISC_CB_PRIV_LEN 20
390 	unsigned char		data[QDISC_CB_PRIV_LEN];
391 	u16			mru;
392 	bool			post_ct;
393 };
394 
395 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
396 
397 struct tcf_chain {
398 	/* Protects filter_chain. */
399 	struct mutex filter_chain_lock;
400 	struct tcf_proto __rcu *filter_chain;
401 	struct list_head list;
402 	struct tcf_block *block;
403 	u32 index; /* chain index */
404 	unsigned int refcnt;
405 	unsigned int action_refcnt;
406 	bool explicitly_created;
407 	bool flushing;
408 	const struct tcf_proto_ops *tmplt_ops;
409 	void *tmplt_priv;
410 	struct rcu_head rcu;
411 };
412 
413 struct tcf_block {
414 	/* Lock protects tcf_block and lifetime-management data of chains
415 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
416 	 */
417 	struct mutex lock;
418 	struct list_head chain_list;
419 	u32 index; /* block index for shared blocks */
420 	u32 classid; /* which class this block belongs to */
421 	refcount_t refcnt;
422 	struct net *net;
423 	struct Qdisc *q;
424 	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
425 	struct flow_block flow_block;
426 	struct list_head owner_list;
427 	bool keep_dst;
428 	atomic_t offloadcnt; /* Number of oddloaded filters */
429 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
430 	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
431 	struct {
432 		struct tcf_chain *chain;
433 		struct list_head filter_chain_list;
434 	} chain0;
435 	struct rcu_head rcu;
436 	DECLARE_HASHTABLE(proto_destroy_ht, 7);
437 	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
438 };
439 
440 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
441 {
442 	return lockdep_is_held(&chain->filter_chain_lock);
443 }
444 
445 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
446 {
447 	return lockdep_is_held(&tp->lock);
448 }
449 
450 #define tcf_chain_dereference(p, chain)					\
451 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
452 
453 #define tcf_proto_dereference(p, tp)					\
454 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
455 
456 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
457 {
458 	struct qdisc_skb_cb *qcb;
459 
460 	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
461 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
462 }
463 
464 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
465 {
466 	return this_cpu_ptr(q->cpu_qstats)->qlen;
467 }
468 
469 static inline int qdisc_qlen(const struct Qdisc *q)
470 {
471 	return q->q.qlen;
472 }
473 
474 static inline int qdisc_qlen_sum(const struct Qdisc *q)
475 {
476 	__u32 qlen = q->qstats.qlen;
477 	int i;
478 
479 	if (qdisc_is_percpu_stats(q)) {
480 		for_each_possible_cpu(i)
481 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
482 	} else {
483 		qlen += q->q.qlen;
484 	}
485 
486 	return qlen;
487 }
488 
489 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
490 {
491 	return (struct qdisc_skb_cb *)skb->cb;
492 }
493 
494 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
495 {
496 	return &qdisc->q.lock;
497 }
498 
499 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
500 {
501 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
502 
503 	return q;
504 }
505 
506 static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
507 {
508 	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
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(struct Qdisc *q)
557 {
558 	if (q->flags & TCQ_F_MQROOT)
559 		spin_lock_bh(qdisc_lock(q));
560 	else
561 		spin_lock_bh(qdisc_root_sleeping_lock(q));
562 }
563 
564 static inline void sch_tree_unlock(struct Qdisc *q)
565 {
566 	if (q->flags & TCQ_F_MQROOT)
567 		spin_unlock_bh(qdisc_lock(q));
568 	else
569 		spin_unlock_bh(qdisc_root_sleeping_lock(q));
570 }
571 
572 extern struct Qdisc noop_qdisc;
573 extern struct Qdisc_ops noop_qdisc_ops;
574 extern struct Qdisc_ops pfifo_fast_ops;
575 extern struct Qdisc_ops mq_qdisc_ops;
576 extern struct Qdisc_ops noqueue_qdisc_ops;
577 extern const struct Qdisc_ops *default_qdisc_ops;
578 static inline const struct Qdisc_ops *
579 get_default_qdisc_ops(const struct net_device *dev, int ntx)
580 {
581 	return ntx < dev->real_num_tx_queues ?
582 			default_qdisc_ops : &pfifo_fast_ops;
583 }
584 
585 struct Qdisc_class_common {
586 	u32			classid;
587 	struct hlist_node	hnode;
588 };
589 
590 struct Qdisc_class_hash {
591 	struct hlist_head	*hash;
592 	unsigned int		hashsize;
593 	unsigned int		hashmask;
594 	unsigned int		hashelems;
595 };
596 
597 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
598 {
599 	id ^= id >> 8;
600 	id ^= id >> 4;
601 	return id & mask;
602 }
603 
604 static inline struct Qdisc_class_common *
605 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
606 {
607 	struct Qdisc_class_common *cl;
608 	unsigned int h;
609 
610 	if (!id)
611 		return NULL;
612 
613 	h = qdisc_class_hash(id, hash->hashmask);
614 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
615 		if (cl->classid == id)
616 			return cl;
617 	}
618 	return NULL;
619 }
620 
621 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
622 {
623 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
624 
625 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
626 }
627 
628 int qdisc_class_hash_init(struct Qdisc_class_hash *);
629 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
630 			     struct Qdisc_class_common *);
631 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
632 			     struct Qdisc_class_common *);
633 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
634 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
635 
636 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
637 void dev_init_scheduler(struct net_device *dev);
638 void dev_shutdown(struct net_device *dev);
639 void dev_activate(struct net_device *dev);
640 void dev_deactivate(struct net_device *dev);
641 void dev_deactivate_many(struct list_head *head);
642 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
643 			      struct Qdisc *qdisc);
644 void qdisc_reset(struct Qdisc *qdisc);
645 void qdisc_put(struct Qdisc *qdisc);
646 void qdisc_put_unlocked(struct Qdisc *qdisc);
647 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
648 #ifdef CONFIG_NET_SCHED
649 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
650 			      void *type_data);
651 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
652 				struct Qdisc *new, struct Qdisc *old,
653 				enum tc_setup_type type, void *type_data,
654 				struct netlink_ext_ack *extack);
655 #else
656 static inline int
657 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
658 			  void *type_data)
659 {
660 	q->flags &= ~TCQ_F_OFFLOADED;
661 	return 0;
662 }
663 
664 static inline void
665 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
666 			   struct Qdisc *new, struct Qdisc *old,
667 			   enum tc_setup_type type, void *type_data,
668 			   struct netlink_ext_ack *extack)
669 {
670 }
671 #endif
672 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
673 			  const struct Qdisc_ops *ops,
674 			  struct netlink_ext_ack *extack);
675 void qdisc_free(struct Qdisc *qdisc);
676 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
677 				const struct Qdisc_ops *ops, u32 parentid,
678 				struct netlink_ext_ack *extack);
679 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
680 			       const struct qdisc_size_table *stab);
681 int skb_do_redirect(struct sk_buff *);
682 
683 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
684 {
685 #ifdef CONFIG_NET_CLS_ACT
686 	return skb->tc_at_ingress;
687 #else
688 	return false;
689 #endif
690 }
691 
692 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
693 {
694 #ifdef CONFIG_NET_CLS_ACT
695 	if (skb->tc_skip_classify) {
696 		skb->tc_skip_classify = 0;
697 		return true;
698 	}
699 #endif
700 	return false;
701 }
702 
703 /* Reset all TX qdiscs greater than index of a device.  */
704 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
705 {
706 	struct Qdisc *qdisc;
707 
708 	for (; i < dev->num_tx_queues; i++) {
709 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
710 		if (qdisc) {
711 			spin_lock_bh(qdisc_lock(qdisc));
712 			qdisc_reset(qdisc);
713 			spin_unlock_bh(qdisc_lock(qdisc));
714 		}
715 	}
716 }
717 
718 /* Are all TX queues of the device empty?  */
719 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
720 {
721 	unsigned int i;
722 
723 	rcu_read_lock();
724 	for (i = 0; i < dev->num_tx_queues; i++) {
725 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
726 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
727 
728 		if (!qdisc_is_empty(q)) {
729 			rcu_read_unlock();
730 			return false;
731 		}
732 	}
733 	rcu_read_unlock();
734 	return true;
735 }
736 
737 /* Are any of the TX qdiscs changing?  */
738 static inline bool qdisc_tx_changing(const struct net_device *dev)
739 {
740 	unsigned int i;
741 
742 	for (i = 0; i < dev->num_tx_queues; i++) {
743 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
744 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
745 			return true;
746 	}
747 	return false;
748 }
749 
750 /* Is the device using the noop qdisc on all queues?  */
751 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
752 {
753 	unsigned int i;
754 
755 	for (i = 0; i < dev->num_tx_queues; i++) {
756 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
757 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
758 			return false;
759 	}
760 	return true;
761 }
762 
763 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
764 {
765 	return qdisc_skb_cb(skb)->pkt_len;
766 }
767 
768 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
769 enum net_xmit_qdisc_t {
770 	__NET_XMIT_STOLEN = 0x00010000,
771 	__NET_XMIT_BYPASS = 0x00020000,
772 };
773 
774 #ifdef CONFIG_NET_CLS_ACT
775 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
776 #else
777 #define net_xmit_drop_count(e)	(1)
778 #endif
779 
780 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
781 					   const struct Qdisc *sch)
782 {
783 #ifdef CONFIG_NET_SCHED
784 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
785 
786 	if (stab)
787 		__qdisc_calculate_pkt_len(skb, stab);
788 #endif
789 }
790 
791 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
792 				struct sk_buff **to_free)
793 {
794 	qdisc_calculate_pkt_len(skb, sch);
795 	return sch->enqueue(skb, sch, to_free);
796 }
797 
798 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
799 				  __u64 bytes, __u32 packets)
800 {
801 	bstats->bytes += bytes;
802 	bstats->packets += packets;
803 }
804 
805 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
806 				 const struct sk_buff *skb)
807 {
808 	_bstats_update(bstats,
809 		       qdisc_pkt_len(skb),
810 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
811 }
812 
813 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
814 				      __u64 bytes, __u32 packets)
815 {
816 	u64_stats_update_begin(&bstats->syncp);
817 	_bstats_update(&bstats->bstats, bytes, packets);
818 	u64_stats_update_end(&bstats->syncp);
819 }
820 
821 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
822 				     const struct sk_buff *skb)
823 {
824 	u64_stats_update_begin(&bstats->syncp);
825 	bstats_update(&bstats->bstats, skb);
826 	u64_stats_update_end(&bstats->syncp);
827 }
828 
829 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
830 					   const struct sk_buff *skb)
831 {
832 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
833 }
834 
835 static inline void qdisc_bstats_update(struct Qdisc *sch,
836 				       const struct sk_buff *skb)
837 {
838 	bstats_update(&sch->bstats, skb);
839 }
840 
841 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
842 					    const struct sk_buff *skb)
843 {
844 	sch->qstats.backlog -= qdisc_pkt_len(skb);
845 }
846 
847 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
848 						const struct sk_buff *skb)
849 {
850 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
851 }
852 
853 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
854 					    const struct sk_buff *skb)
855 {
856 	sch->qstats.backlog += qdisc_pkt_len(skb);
857 }
858 
859 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
860 						const struct sk_buff *skb)
861 {
862 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
863 }
864 
865 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
866 {
867 	this_cpu_inc(sch->cpu_qstats->qlen);
868 }
869 
870 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
871 {
872 	this_cpu_dec(sch->cpu_qstats->qlen);
873 }
874 
875 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
876 {
877 	this_cpu_inc(sch->cpu_qstats->requeues);
878 }
879 
880 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
881 {
882 	sch->qstats.drops += count;
883 }
884 
885 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
886 {
887 	qstats->drops++;
888 }
889 
890 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
891 {
892 	qstats->overlimits++;
893 }
894 
895 static inline void qdisc_qstats_drop(struct Qdisc *sch)
896 {
897 	qstats_drop_inc(&sch->qstats);
898 }
899 
900 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
901 {
902 	this_cpu_inc(sch->cpu_qstats->drops);
903 }
904 
905 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
906 {
907 	sch->qstats.overlimits++;
908 }
909 
910 static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
911 {
912 	__u32 qlen = qdisc_qlen_sum(sch);
913 
914 	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
915 }
916 
917 static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
918 					     __u32 *backlog)
919 {
920 	struct gnet_stats_queue qstats = { 0 };
921 	__u32 len = qdisc_qlen_sum(sch);
922 
923 	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
924 	*qlen = qstats.qlen;
925 	*backlog = qstats.backlog;
926 }
927 
928 static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
929 {
930 	__u32 qlen, backlog;
931 
932 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
933 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
934 }
935 
936 static inline void qdisc_purge_queue(struct Qdisc *sch)
937 {
938 	__u32 qlen, backlog;
939 
940 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
941 	qdisc_reset(sch);
942 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
943 }
944 
945 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
946 {
947 	qh->head = NULL;
948 	qh->tail = NULL;
949 	qh->qlen = 0;
950 }
951 
952 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
953 					struct qdisc_skb_head *qh)
954 {
955 	struct sk_buff *last = qh->tail;
956 
957 	if (last) {
958 		skb->next = NULL;
959 		last->next = skb;
960 		qh->tail = skb;
961 	} else {
962 		qh->tail = skb;
963 		qh->head = skb;
964 	}
965 	qh->qlen++;
966 }
967 
968 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
969 {
970 	__qdisc_enqueue_tail(skb, &sch->q);
971 	qdisc_qstats_backlog_inc(sch, skb);
972 	return NET_XMIT_SUCCESS;
973 }
974 
975 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
976 					struct qdisc_skb_head *qh)
977 {
978 	skb->next = qh->head;
979 
980 	if (!qh->head)
981 		qh->tail = skb;
982 	qh->head = skb;
983 	qh->qlen++;
984 }
985 
986 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
987 {
988 	struct sk_buff *skb = qh->head;
989 
990 	if (likely(skb != NULL)) {
991 		qh->head = skb->next;
992 		qh->qlen--;
993 		if (qh->head == NULL)
994 			qh->tail = NULL;
995 		skb->next = NULL;
996 	}
997 
998 	return skb;
999 }
1000 
1001 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
1002 {
1003 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
1004 
1005 	if (likely(skb != NULL)) {
1006 		qdisc_qstats_backlog_dec(sch, skb);
1007 		qdisc_bstats_update(sch, skb);
1008 	}
1009 
1010 	return skb;
1011 }
1012 
1013 /* Instead of calling kfree_skb() while root qdisc lock is held,
1014  * queue the skb for future freeing at end of __dev_xmit_skb()
1015  */
1016 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1017 {
1018 	skb->next = *to_free;
1019 	*to_free = skb;
1020 }
1021 
1022 static inline void __qdisc_drop_all(struct sk_buff *skb,
1023 				    struct sk_buff **to_free)
1024 {
1025 	if (skb->prev)
1026 		skb->prev->next = *to_free;
1027 	else
1028 		skb->next = *to_free;
1029 	*to_free = skb;
1030 }
1031 
1032 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1033 						   struct qdisc_skb_head *qh,
1034 						   struct sk_buff **to_free)
1035 {
1036 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1037 
1038 	if (likely(skb != NULL)) {
1039 		unsigned int len = qdisc_pkt_len(skb);
1040 
1041 		qdisc_qstats_backlog_dec(sch, skb);
1042 		__qdisc_drop(skb, to_free);
1043 		return len;
1044 	}
1045 
1046 	return 0;
1047 }
1048 
1049 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1050 {
1051 	const struct qdisc_skb_head *qh = &sch->q;
1052 
1053 	return qh->head;
1054 }
1055 
1056 /* generic pseudo peek method for non-work-conserving qdisc */
1057 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1058 {
1059 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1060 
1061 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1062 	if (!skb) {
1063 		skb = sch->dequeue(sch);
1064 
1065 		if (skb) {
1066 			__skb_queue_head(&sch->gso_skb, skb);
1067 			/* it's still part of the queue */
1068 			qdisc_qstats_backlog_inc(sch, skb);
1069 			sch->q.qlen++;
1070 		}
1071 	}
1072 
1073 	return skb;
1074 }
1075 
1076 static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1077 						 struct sk_buff *skb)
1078 {
1079 	if (qdisc_is_percpu_stats(sch)) {
1080 		qdisc_qstats_cpu_backlog_dec(sch, skb);
1081 		qdisc_bstats_cpu_update(sch, skb);
1082 		qdisc_qstats_cpu_qlen_dec(sch);
1083 	} else {
1084 		qdisc_qstats_backlog_dec(sch, skb);
1085 		qdisc_bstats_update(sch, skb);
1086 		sch->q.qlen--;
1087 	}
1088 }
1089 
1090 static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1091 						 unsigned int pkt_len)
1092 {
1093 	if (qdisc_is_percpu_stats(sch)) {
1094 		qdisc_qstats_cpu_qlen_inc(sch);
1095 		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1096 	} else {
1097 		sch->qstats.backlog += pkt_len;
1098 		sch->q.qlen++;
1099 	}
1100 }
1101 
1102 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1103 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1104 {
1105 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1106 
1107 	if (skb) {
1108 		skb = __skb_dequeue(&sch->gso_skb);
1109 		if (qdisc_is_percpu_stats(sch)) {
1110 			qdisc_qstats_cpu_backlog_dec(sch, skb);
1111 			qdisc_qstats_cpu_qlen_dec(sch);
1112 		} else {
1113 			qdisc_qstats_backlog_dec(sch, skb);
1114 			sch->q.qlen--;
1115 		}
1116 	} else {
1117 		skb = sch->dequeue(sch);
1118 	}
1119 
1120 	return skb;
1121 }
1122 
1123 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1124 {
1125 	/*
1126 	 * We do not know the backlog in bytes of this list, it
1127 	 * is up to the caller to correct it
1128 	 */
1129 	ASSERT_RTNL();
1130 	if (qh->qlen) {
1131 		rtnl_kfree_skbs(qh->head, qh->tail);
1132 
1133 		qh->head = NULL;
1134 		qh->tail = NULL;
1135 		qh->qlen = 0;
1136 	}
1137 }
1138 
1139 static inline void qdisc_reset_queue(struct Qdisc *sch)
1140 {
1141 	__qdisc_reset_queue(&sch->q);
1142 	sch->qstats.backlog = 0;
1143 }
1144 
1145 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1146 					  struct Qdisc **pold)
1147 {
1148 	struct Qdisc *old;
1149 
1150 	sch_tree_lock(sch);
1151 	old = *pold;
1152 	*pold = new;
1153 	if (old != NULL)
1154 		qdisc_purge_queue(old);
1155 	sch_tree_unlock(sch);
1156 
1157 	return old;
1158 }
1159 
1160 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1161 {
1162 	rtnl_kfree_skbs(skb, skb);
1163 	qdisc_qstats_drop(sch);
1164 }
1165 
1166 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1167 				 struct sk_buff **to_free)
1168 {
1169 	__qdisc_drop(skb, to_free);
1170 	qdisc_qstats_cpu_drop(sch);
1171 
1172 	return NET_XMIT_DROP;
1173 }
1174 
1175 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1176 			     struct sk_buff **to_free)
1177 {
1178 	__qdisc_drop(skb, to_free);
1179 	qdisc_qstats_drop(sch);
1180 
1181 	return NET_XMIT_DROP;
1182 }
1183 
1184 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1185 				 struct sk_buff **to_free)
1186 {
1187 	__qdisc_drop_all(skb, to_free);
1188 	qdisc_qstats_drop(sch);
1189 
1190 	return NET_XMIT_DROP;
1191 }
1192 
1193 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1194    long it will take to send a packet given its size.
1195  */
1196 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1197 {
1198 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1199 	if (slot < 0)
1200 		slot = 0;
1201 	slot >>= rtab->rate.cell_log;
1202 	if (slot > 255)
1203 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1204 	return rtab->data[slot];
1205 }
1206 
1207 struct psched_ratecfg {
1208 	u64	rate_bytes_ps; /* bytes per second */
1209 	u32	mult;
1210 	u16	overhead;
1211 	u8	linklayer;
1212 	u8	shift;
1213 };
1214 
1215 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1216 				unsigned int len)
1217 {
1218 	len += r->overhead;
1219 
1220 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1221 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1222 
1223 	return ((u64)len * r->mult) >> r->shift;
1224 }
1225 
1226 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1227 			       const struct tc_ratespec *conf,
1228 			       u64 rate64);
1229 
1230 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1231 					  const struct psched_ratecfg *r)
1232 {
1233 	memset(res, 0, sizeof(*res));
1234 
1235 	/* legacy struct tc_ratespec has a 32bit @rate field
1236 	 * Qdisc using 64bit rate should add new attributes
1237 	 * in order to maintain compatibility.
1238 	 */
1239 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1240 
1241 	res->overhead = r->overhead;
1242 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1243 }
1244 
1245 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1246  * The fast path only needs to access filter list and to update stats
1247  */
1248 struct mini_Qdisc {
1249 	struct tcf_proto *filter_list;
1250 	struct tcf_block *block;
1251 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1252 	struct gnet_stats_queue	__percpu *cpu_qstats;
1253 	struct rcu_head rcu;
1254 };
1255 
1256 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1257 						const struct sk_buff *skb)
1258 {
1259 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1260 }
1261 
1262 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1263 {
1264 	this_cpu_inc(miniq->cpu_qstats->drops);
1265 }
1266 
1267 struct mini_Qdisc_pair {
1268 	struct mini_Qdisc miniq1;
1269 	struct mini_Qdisc miniq2;
1270 	struct mini_Qdisc __rcu **p_miniq;
1271 };
1272 
1273 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1274 			  struct tcf_proto *tp_head);
1275 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1276 			  struct mini_Qdisc __rcu **p_miniq);
1277 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1278 				struct tcf_block *block);
1279 
1280 int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));
1281 
1282 #endif
1283