xref: /linux/include/net/sch_generic.h (revision e8e507a8ac90d48053dfdea9d4855495b0204956)
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 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
215 
216 	/* Filter manipulation */
217 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
218 					     unsigned long arg,
219 					     struct netlink_ext_ack *extack);
220 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
221 					u32 classid);
222 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
223 
224 	/* rtnetlink specific */
225 	int			(*dump)(struct Qdisc *, unsigned long,
226 					struct sk_buff *skb, struct tcmsg*);
227 	int			(*dump_stats)(struct Qdisc *, unsigned long,
228 					struct gnet_dump *);
229 };
230 
231 /* Qdisc_class_ops flag values */
232 
233 /* Implements API that doesn't require rtnl lock */
234 enum qdisc_class_ops_flags {
235 	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
236 };
237 
238 struct Qdisc_ops {
239 	struct Qdisc_ops	*next;
240 	const struct Qdisc_class_ops	*cl_ops;
241 	char			id[IFNAMSIZ];
242 	int			priv_size;
243 	unsigned int		static_flags;
244 
245 	int 			(*enqueue)(struct sk_buff *skb,
246 					   struct Qdisc *sch,
247 					   struct sk_buff **to_free);
248 	struct sk_buff *	(*dequeue)(struct Qdisc *);
249 	struct sk_buff *	(*peek)(struct Qdisc *);
250 
251 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
252 					struct netlink_ext_ack *extack);
253 	void			(*reset)(struct Qdisc *);
254 	void			(*destroy)(struct Qdisc *);
255 	int			(*change)(struct Qdisc *sch,
256 					  struct nlattr *arg,
257 					  struct netlink_ext_ack *extack);
258 	void			(*attach)(struct Qdisc *sch);
259 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
260 
261 	int			(*dump)(struct Qdisc *, struct sk_buff *);
262 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
263 
264 	void			(*ingress_block_set)(struct Qdisc *sch,
265 						     u32 block_index);
266 	void			(*egress_block_set)(struct Qdisc *sch,
267 						    u32 block_index);
268 	u32			(*ingress_block_get)(struct Qdisc *sch);
269 	u32			(*egress_block_get)(struct Qdisc *sch);
270 
271 	struct module		*owner;
272 };
273 
274 
275 struct tcf_result {
276 	union {
277 		struct {
278 			unsigned long	class;
279 			u32		classid;
280 		};
281 		const struct tcf_proto *goto_tp;
282 
283 		/* used in the skb_tc_reinsert function */
284 		struct {
285 			bool		ingress;
286 			struct gnet_stats_queue *qstats;
287 		};
288 	};
289 };
290 
291 struct tcf_chain;
292 
293 struct tcf_proto_ops {
294 	struct list_head	head;
295 	char			kind[IFNAMSIZ];
296 
297 	int			(*classify)(struct sk_buff *,
298 					    const struct tcf_proto *,
299 					    struct tcf_result *);
300 	int			(*init)(struct tcf_proto*);
301 	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
302 					   struct netlink_ext_ack *extack);
303 
304 	void*			(*get)(struct tcf_proto*, u32 handle);
305 	void			(*put)(struct tcf_proto *tp, void *f);
306 	int			(*change)(struct net *net, struct sk_buff *,
307 					struct tcf_proto*, unsigned long,
308 					u32 handle, struct nlattr **,
309 					void **, bool, bool,
310 					struct netlink_ext_ack *);
311 	int			(*delete)(struct tcf_proto *tp, void *arg,
312 					  bool *last, bool rtnl_held,
313 					  struct netlink_ext_ack *);
314 	bool			(*delete_empty)(struct tcf_proto *tp);
315 	void			(*walk)(struct tcf_proto *tp,
316 					struct tcf_walker *arg, bool rtnl_held);
317 	int			(*reoffload)(struct tcf_proto *tp, bool add,
318 					     flow_setup_cb_t *cb, void *cb_priv,
319 					     struct netlink_ext_ack *extack);
320 	void			(*hw_add)(struct tcf_proto *tp,
321 					  void *type_data);
322 	void			(*hw_del)(struct tcf_proto *tp,
323 					  void *type_data);
324 	void			(*bind_class)(void *, u32, unsigned long,
325 					      void *, unsigned long);
326 	void *			(*tmplt_create)(struct net *net,
327 						struct tcf_chain *chain,
328 						struct nlattr **tca,
329 						struct netlink_ext_ack *extack);
330 	void			(*tmplt_destroy)(void *tmplt_priv);
331 
332 	/* rtnetlink specific */
333 	int			(*dump)(struct net*, struct tcf_proto*, void *,
334 					struct sk_buff *skb, struct tcmsg*,
335 					bool);
336 	int			(*terse_dump)(struct net *net,
337 					      struct tcf_proto *tp, void *fh,
338 					      struct sk_buff *skb,
339 					      struct tcmsg *t, bool rtnl_held);
340 	int			(*tmplt_dump)(struct sk_buff *skb,
341 					      struct net *net,
342 					      void *tmplt_priv);
343 
344 	struct module		*owner;
345 	int			flags;
346 };
347 
348 /* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
349  * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
350  * conditions can occur when filters are inserted/deleted simultaneously.
351  */
352 enum tcf_proto_ops_flags {
353 	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
354 };
355 
356 struct tcf_proto {
357 	/* Fast access part */
358 	struct tcf_proto __rcu	*next;
359 	void __rcu		*root;
360 
361 	/* called under RCU BH lock*/
362 	int			(*classify)(struct sk_buff *,
363 					    const struct tcf_proto *,
364 					    struct tcf_result *);
365 	__be16			protocol;
366 
367 	/* All the rest */
368 	u32			prio;
369 	void			*data;
370 	const struct tcf_proto_ops	*ops;
371 	struct tcf_chain	*chain;
372 	/* Lock protects tcf_proto shared state and can be used by unlocked
373 	 * classifiers to protect their private data.
374 	 */
375 	spinlock_t		lock;
376 	bool			deleting;
377 	refcount_t		refcnt;
378 	struct rcu_head		rcu;
379 	struct hlist_node	destroy_ht_node;
380 };
381 
382 struct qdisc_skb_cb {
383 	struct {
384 		unsigned int		pkt_len;
385 		u16			slave_dev_queue_mapping;
386 		u16			tc_classid;
387 	};
388 #define QDISC_CB_PRIV_LEN 20
389 	unsigned char		data[QDISC_CB_PRIV_LEN];
390 	u16			mru;
391 	bool			post_ct;
392 };
393 
394 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
395 
396 struct tcf_chain {
397 	/* Protects filter_chain. */
398 	struct mutex filter_chain_lock;
399 	struct tcf_proto __rcu *filter_chain;
400 	struct list_head list;
401 	struct tcf_block *block;
402 	u32 index; /* chain index */
403 	unsigned int refcnt;
404 	unsigned int action_refcnt;
405 	bool explicitly_created;
406 	bool flushing;
407 	const struct tcf_proto_ops *tmplt_ops;
408 	void *tmplt_priv;
409 	struct rcu_head rcu;
410 };
411 
412 struct tcf_block {
413 	/* Lock protects tcf_block and lifetime-management data of chains
414 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
415 	 */
416 	struct mutex lock;
417 	struct list_head chain_list;
418 	u32 index; /* block index for shared blocks */
419 	u32 classid; /* which class this block belongs to */
420 	refcount_t refcnt;
421 	struct net *net;
422 	struct Qdisc *q;
423 	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
424 	struct flow_block flow_block;
425 	struct list_head owner_list;
426 	bool keep_dst;
427 	atomic_t offloadcnt; /* Number of oddloaded filters */
428 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
429 	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
430 	struct {
431 		struct tcf_chain *chain;
432 		struct list_head filter_chain_list;
433 	} chain0;
434 	struct rcu_head rcu;
435 	DECLARE_HASHTABLE(proto_destroy_ht, 7);
436 	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
437 };
438 
439 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
440 {
441 	return lockdep_is_held(&chain->filter_chain_lock);
442 }
443 
444 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
445 {
446 	return lockdep_is_held(&tp->lock);
447 }
448 
449 #define tcf_chain_dereference(p, chain)					\
450 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
451 
452 #define tcf_proto_dereference(p, tp)					\
453 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
454 
455 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
456 {
457 	struct qdisc_skb_cb *qcb;
458 
459 	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
460 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
461 }
462 
463 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
464 {
465 	return this_cpu_ptr(q->cpu_qstats)->qlen;
466 }
467 
468 static inline int qdisc_qlen(const struct Qdisc *q)
469 {
470 	return q->q.qlen;
471 }
472 
473 static inline int qdisc_qlen_sum(const struct Qdisc *q)
474 {
475 	__u32 qlen = q->qstats.qlen;
476 	int i;
477 
478 	if (qdisc_is_percpu_stats(q)) {
479 		for_each_possible_cpu(i)
480 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
481 	} else {
482 		qlen += q->q.qlen;
483 	}
484 
485 	return qlen;
486 }
487 
488 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
489 {
490 	return (struct qdisc_skb_cb *)skb->cb;
491 }
492 
493 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
494 {
495 	return &qdisc->q.lock;
496 }
497 
498 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
499 {
500 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
501 
502 	return q;
503 }
504 
505 static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
506 {
507 	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
508 }
509 
510 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
511 {
512 	return qdisc->dev_queue->qdisc_sleeping;
513 }
514 
515 /* The qdisc root lock is a mechanism by which to top level
516  * of a qdisc tree can be locked from any qdisc node in the
517  * forest.  This allows changing the configuration of some
518  * aspect of the qdisc tree while blocking out asynchronous
519  * qdisc access in the packet processing paths.
520  *
521  * It is only legal to do this when the root will not change
522  * on us.  Otherwise we'll potentially lock the wrong qdisc
523  * root.  This is enforced by holding the RTNL semaphore, which
524  * all users of this lock accessor must do.
525  */
526 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
527 {
528 	struct Qdisc *root = qdisc_root(qdisc);
529 
530 	ASSERT_RTNL();
531 	return qdisc_lock(root);
532 }
533 
534 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
535 {
536 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
537 
538 	ASSERT_RTNL();
539 	return qdisc_lock(root);
540 }
541 
542 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
543 {
544 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
545 
546 	ASSERT_RTNL();
547 	return &root->running;
548 }
549 
550 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
551 {
552 	return qdisc->dev_queue->dev;
553 }
554 
555 static inline void sch_tree_lock(const struct Qdisc *q)
556 {
557 	spin_lock_bh(qdisc_root_sleeping_lock(q));
558 }
559 
560 static inline void sch_tree_unlock(const struct Qdisc *q)
561 {
562 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
563 }
564 
565 extern struct Qdisc noop_qdisc;
566 extern struct Qdisc_ops noop_qdisc_ops;
567 extern struct Qdisc_ops pfifo_fast_ops;
568 extern struct Qdisc_ops mq_qdisc_ops;
569 extern struct Qdisc_ops noqueue_qdisc_ops;
570 extern const struct Qdisc_ops *default_qdisc_ops;
571 static inline const struct Qdisc_ops *
572 get_default_qdisc_ops(const struct net_device *dev, int ntx)
573 {
574 	return ntx < dev->real_num_tx_queues ?
575 			default_qdisc_ops : &pfifo_fast_ops;
576 }
577 
578 struct Qdisc_class_common {
579 	u32			classid;
580 	struct hlist_node	hnode;
581 };
582 
583 struct Qdisc_class_hash {
584 	struct hlist_head	*hash;
585 	unsigned int		hashsize;
586 	unsigned int		hashmask;
587 	unsigned int		hashelems;
588 };
589 
590 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
591 {
592 	id ^= id >> 8;
593 	id ^= id >> 4;
594 	return id & mask;
595 }
596 
597 static inline struct Qdisc_class_common *
598 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
599 {
600 	struct Qdisc_class_common *cl;
601 	unsigned int h;
602 
603 	if (!id)
604 		return NULL;
605 
606 	h = qdisc_class_hash(id, hash->hashmask);
607 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
608 		if (cl->classid == id)
609 			return cl;
610 	}
611 	return NULL;
612 }
613 
614 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
615 {
616 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
617 
618 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
619 }
620 
621 int qdisc_class_hash_init(struct Qdisc_class_hash *);
622 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
623 			     struct Qdisc_class_common *);
624 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
625 			     struct Qdisc_class_common *);
626 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
627 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
628 
629 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
630 void dev_init_scheduler(struct net_device *dev);
631 void dev_shutdown(struct net_device *dev);
632 void dev_activate(struct net_device *dev);
633 void dev_deactivate(struct net_device *dev);
634 void dev_deactivate_many(struct list_head *head);
635 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
636 			      struct Qdisc *qdisc);
637 void qdisc_reset(struct Qdisc *qdisc);
638 void qdisc_put(struct Qdisc *qdisc);
639 void qdisc_put_unlocked(struct Qdisc *qdisc);
640 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
641 #ifdef CONFIG_NET_SCHED
642 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
643 			      void *type_data);
644 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
645 				struct Qdisc *new, struct Qdisc *old,
646 				enum tc_setup_type type, void *type_data,
647 				struct netlink_ext_ack *extack);
648 #else
649 static inline int
650 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
651 			  void *type_data)
652 {
653 	q->flags &= ~TCQ_F_OFFLOADED;
654 	return 0;
655 }
656 
657 static inline void
658 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
659 			   struct Qdisc *new, struct Qdisc *old,
660 			   enum tc_setup_type type, void *type_data,
661 			   struct netlink_ext_ack *extack)
662 {
663 }
664 #endif
665 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
666 			  const struct Qdisc_ops *ops,
667 			  struct netlink_ext_ack *extack);
668 void qdisc_free(struct Qdisc *qdisc);
669 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
670 				const struct Qdisc_ops *ops, u32 parentid,
671 				struct netlink_ext_ack *extack);
672 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
673 			       const struct qdisc_size_table *stab);
674 int skb_do_redirect(struct sk_buff *);
675 
676 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
677 {
678 #ifdef CONFIG_NET_CLS_ACT
679 	return skb->tc_at_ingress;
680 #else
681 	return false;
682 #endif
683 }
684 
685 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
686 {
687 #ifdef CONFIG_NET_CLS_ACT
688 	if (skb->tc_skip_classify) {
689 		skb->tc_skip_classify = 0;
690 		return true;
691 	}
692 #endif
693 	return false;
694 }
695 
696 /* Reset all TX qdiscs greater than index of a device.  */
697 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
698 {
699 	struct Qdisc *qdisc;
700 
701 	for (; i < dev->num_tx_queues; i++) {
702 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
703 		if (qdisc) {
704 			spin_lock_bh(qdisc_lock(qdisc));
705 			qdisc_reset(qdisc);
706 			spin_unlock_bh(qdisc_lock(qdisc));
707 		}
708 	}
709 }
710 
711 /* Are all TX queues of the device empty?  */
712 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
713 {
714 	unsigned int i;
715 
716 	rcu_read_lock();
717 	for (i = 0; i < dev->num_tx_queues; i++) {
718 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
719 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
720 
721 		if (!qdisc_is_empty(q)) {
722 			rcu_read_unlock();
723 			return false;
724 		}
725 	}
726 	rcu_read_unlock();
727 	return true;
728 }
729 
730 /* Are any of the TX qdiscs changing?  */
731 static inline bool qdisc_tx_changing(const struct net_device *dev)
732 {
733 	unsigned int i;
734 
735 	for (i = 0; i < dev->num_tx_queues; i++) {
736 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
737 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
738 			return true;
739 	}
740 	return false;
741 }
742 
743 /* Is the device using the noop qdisc on all queues?  */
744 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
745 {
746 	unsigned int i;
747 
748 	for (i = 0; i < dev->num_tx_queues; i++) {
749 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
750 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
751 			return false;
752 	}
753 	return true;
754 }
755 
756 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
757 {
758 	return qdisc_skb_cb(skb)->pkt_len;
759 }
760 
761 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
762 enum net_xmit_qdisc_t {
763 	__NET_XMIT_STOLEN = 0x00010000,
764 	__NET_XMIT_BYPASS = 0x00020000,
765 };
766 
767 #ifdef CONFIG_NET_CLS_ACT
768 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
769 #else
770 #define net_xmit_drop_count(e)	(1)
771 #endif
772 
773 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
774 					   const struct Qdisc *sch)
775 {
776 #ifdef CONFIG_NET_SCHED
777 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
778 
779 	if (stab)
780 		__qdisc_calculate_pkt_len(skb, stab);
781 #endif
782 }
783 
784 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
785 				struct sk_buff **to_free)
786 {
787 	qdisc_calculate_pkt_len(skb, sch);
788 	return sch->enqueue(skb, sch, to_free);
789 }
790 
791 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
792 				  __u64 bytes, __u32 packets)
793 {
794 	bstats->bytes += bytes;
795 	bstats->packets += packets;
796 }
797 
798 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
799 				 const struct sk_buff *skb)
800 {
801 	_bstats_update(bstats,
802 		       qdisc_pkt_len(skb),
803 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
804 }
805 
806 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
807 				      __u64 bytes, __u32 packets)
808 {
809 	u64_stats_update_begin(&bstats->syncp);
810 	_bstats_update(&bstats->bstats, bytes, packets);
811 	u64_stats_update_end(&bstats->syncp);
812 }
813 
814 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
815 				     const struct sk_buff *skb)
816 {
817 	u64_stats_update_begin(&bstats->syncp);
818 	bstats_update(&bstats->bstats, skb);
819 	u64_stats_update_end(&bstats->syncp);
820 }
821 
822 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
823 					   const struct sk_buff *skb)
824 {
825 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
826 }
827 
828 static inline void qdisc_bstats_update(struct Qdisc *sch,
829 				       const struct sk_buff *skb)
830 {
831 	bstats_update(&sch->bstats, skb);
832 }
833 
834 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
835 					    const struct sk_buff *skb)
836 {
837 	sch->qstats.backlog -= qdisc_pkt_len(skb);
838 }
839 
840 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
841 						const struct sk_buff *skb)
842 {
843 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
844 }
845 
846 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
847 					    const struct sk_buff *skb)
848 {
849 	sch->qstats.backlog += qdisc_pkt_len(skb);
850 }
851 
852 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
853 						const struct sk_buff *skb)
854 {
855 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
856 }
857 
858 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
859 {
860 	this_cpu_inc(sch->cpu_qstats->qlen);
861 }
862 
863 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
864 {
865 	this_cpu_dec(sch->cpu_qstats->qlen);
866 }
867 
868 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
869 {
870 	this_cpu_inc(sch->cpu_qstats->requeues);
871 }
872 
873 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
874 {
875 	sch->qstats.drops += count;
876 }
877 
878 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
879 {
880 	qstats->drops++;
881 }
882 
883 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
884 {
885 	qstats->overlimits++;
886 }
887 
888 static inline void qdisc_qstats_drop(struct Qdisc *sch)
889 {
890 	qstats_drop_inc(&sch->qstats);
891 }
892 
893 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
894 {
895 	this_cpu_inc(sch->cpu_qstats->drops);
896 }
897 
898 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
899 {
900 	sch->qstats.overlimits++;
901 }
902 
903 static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
904 {
905 	__u32 qlen = qdisc_qlen_sum(sch);
906 
907 	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
908 }
909 
910 static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
911 					     __u32 *backlog)
912 {
913 	struct gnet_stats_queue qstats = { 0 };
914 	__u32 len = qdisc_qlen_sum(sch);
915 
916 	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
917 	*qlen = qstats.qlen;
918 	*backlog = qstats.backlog;
919 }
920 
921 static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
922 {
923 	__u32 qlen, backlog;
924 
925 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
926 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
927 }
928 
929 static inline void qdisc_purge_queue(struct Qdisc *sch)
930 {
931 	__u32 qlen, backlog;
932 
933 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
934 	qdisc_reset(sch);
935 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
936 }
937 
938 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
939 {
940 	qh->head = NULL;
941 	qh->tail = NULL;
942 	qh->qlen = 0;
943 }
944 
945 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
946 					struct qdisc_skb_head *qh)
947 {
948 	struct sk_buff *last = qh->tail;
949 
950 	if (last) {
951 		skb->next = NULL;
952 		last->next = skb;
953 		qh->tail = skb;
954 	} else {
955 		qh->tail = skb;
956 		qh->head = skb;
957 	}
958 	qh->qlen++;
959 }
960 
961 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
962 {
963 	__qdisc_enqueue_tail(skb, &sch->q);
964 	qdisc_qstats_backlog_inc(sch, skb);
965 	return NET_XMIT_SUCCESS;
966 }
967 
968 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
969 					struct qdisc_skb_head *qh)
970 {
971 	skb->next = qh->head;
972 
973 	if (!qh->head)
974 		qh->tail = skb;
975 	qh->head = skb;
976 	qh->qlen++;
977 }
978 
979 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
980 {
981 	struct sk_buff *skb = qh->head;
982 
983 	if (likely(skb != NULL)) {
984 		qh->head = skb->next;
985 		qh->qlen--;
986 		if (qh->head == NULL)
987 			qh->tail = NULL;
988 		skb->next = NULL;
989 	}
990 
991 	return skb;
992 }
993 
994 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
995 {
996 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
997 
998 	if (likely(skb != NULL)) {
999 		qdisc_qstats_backlog_dec(sch, skb);
1000 		qdisc_bstats_update(sch, skb);
1001 	}
1002 
1003 	return skb;
1004 }
1005 
1006 /* Instead of calling kfree_skb() while root qdisc lock is held,
1007  * queue the skb for future freeing at end of __dev_xmit_skb()
1008  */
1009 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1010 {
1011 	skb->next = *to_free;
1012 	*to_free = skb;
1013 }
1014 
1015 static inline void __qdisc_drop_all(struct sk_buff *skb,
1016 				    struct sk_buff **to_free)
1017 {
1018 	if (skb->prev)
1019 		skb->prev->next = *to_free;
1020 	else
1021 		skb->next = *to_free;
1022 	*to_free = skb;
1023 }
1024 
1025 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1026 						   struct qdisc_skb_head *qh,
1027 						   struct sk_buff **to_free)
1028 {
1029 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1030 
1031 	if (likely(skb != NULL)) {
1032 		unsigned int len = qdisc_pkt_len(skb);
1033 
1034 		qdisc_qstats_backlog_dec(sch, skb);
1035 		__qdisc_drop(skb, to_free);
1036 		return len;
1037 	}
1038 
1039 	return 0;
1040 }
1041 
1042 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1043 {
1044 	const struct qdisc_skb_head *qh = &sch->q;
1045 
1046 	return qh->head;
1047 }
1048 
1049 /* generic pseudo peek method for non-work-conserving qdisc */
1050 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1051 {
1052 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1053 
1054 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1055 	if (!skb) {
1056 		skb = sch->dequeue(sch);
1057 
1058 		if (skb) {
1059 			__skb_queue_head(&sch->gso_skb, skb);
1060 			/* it's still part of the queue */
1061 			qdisc_qstats_backlog_inc(sch, skb);
1062 			sch->q.qlen++;
1063 		}
1064 	}
1065 
1066 	return skb;
1067 }
1068 
1069 static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1070 						 struct sk_buff *skb)
1071 {
1072 	if (qdisc_is_percpu_stats(sch)) {
1073 		qdisc_qstats_cpu_backlog_dec(sch, skb);
1074 		qdisc_bstats_cpu_update(sch, skb);
1075 		qdisc_qstats_cpu_qlen_dec(sch);
1076 	} else {
1077 		qdisc_qstats_backlog_dec(sch, skb);
1078 		qdisc_bstats_update(sch, skb);
1079 		sch->q.qlen--;
1080 	}
1081 }
1082 
1083 static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1084 						 unsigned int pkt_len)
1085 {
1086 	if (qdisc_is_percpu_stats(sch)) {
1087 		qdisc_qstats_cpu_qlen_inc(sch);
1088 		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1089 	} else {
1090 		sch->qstats.backlog += pkt_len;
1091 		sch->q.qlen++;
1092 	}
1093 }
1094 
1095 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1096 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1097 {
1098 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1099 
1100 	if (skb) {
1101 		skb = __skb_dequeue(&sch->gso_skb);
1102 		if (qdisc_is_percpu_stats(sch)) {
1103 			qdisc_qstats_cpu_backlog_dec(sch, skb);
1104 			qdisc_qstats_cpu_qlen_dec(sch);
1105 		} else {
1106 			qdisc_qstats_backlog_dec(sch, skb);
1107 			sch->q.qlen--;
1108 		}
1109 	} else {
1110 		skb = sch->dequeue(sch);
1111 	}
1112 
1113 	return skb;
1114 }
1115 
1116 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1117 {
1118 	/*
1119 	 * We do not know the backlog in bytes of this list, it
1120 	 * is up to the caller to correct it
1121 	 */
1122 	ASSERT_RTNL();
1123 	if (qh->qlen) {
1124 		rtnl_kfree_skbs(qh->head, qh->tail);
1125 
1126 		qh->head = NULL;
1127 		qh->tail = NULL;
1128 		qh->qlen = 0;
1129 	}
1130 }
1131 
1132 static inline void qdisc_reset_queue(struct Qdisc *sch)
1133 {
1134 	__qdisc_reset_queue(&sch->q);
1135 	sch->qstats.backlog = 0;
1136 }
1137 
1138 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1139 					  struct Qdisc **pold)
1140 {
1141 	struct Qdisc *old;
1142 
1143 	sch_tree_lock(sch);
1144 	old = *pold;
1145 	*pold = new;
1146 	if (old != NULL)
1147 		qdisc_tree_flush_backlog(old);
1148 	sch_tree_unlock(sch);
1149 
1150 	return old;
1151 }
1152 
1153 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1154 {
1155 	rtnl_kfree_skbs(skb, skb);
1156 	qdisc_qstats_drop(sch);
1157 }
1158 
1159 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1160 				 struct sk_buff **to_free)
1161 {
1162 	__qdisc_drop(skb, to_free);
1163 	qdisc_qstats_cpu_drop(sch);
1164 
1165 	return NET_XMIT_DROP;
1166 }
1167 
1168 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1169 			     struct sk_buff **to_free)
1170 {
1171 	__qdisc_drop(skb, to_free);
1172 	qdisc_qstats_drop(sch);
1173 
1174 	return NET_XMIT_DROP;
1175 }
1176 
1177 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1178 				 struct sk_buff **to_free)
1179 {
1180 	__qdisc_drop_all(skb, to_free);
1181 	qdisc_qstats_drop(sch);
1182 
1183 	return NET_XMIT_DROP;
1184 }
1185 
1186 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1187    long it will take to send a packet given its size.
1188  */
1189 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1190 {
1191 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1192 	if (slot < 0)
1193 		slot = 0;
1194 	slot >>= rtab->rate.cell_log;
1195 	if (slot > 255)
1196 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1197 	return rtab->data[slot];
1198 }
1199 
1200 struct psched_ratecfg {
1201 	u64	rate_bytes_ps; /* bytes per second */
1202 	u32	mult;
1203 	u16	overhead;
1204 	u8	linklayer;
1205 	u8	shift;
1206 };
1207 
1208 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1209 				unsigned int len)
1210 {
1211 	len += r->overhead;
1212 
1213 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1214 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1215 
1216 	return ((u64)len * r->mult) >> r->shift;
1217 }
1218 
1219 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1220 			       const struct tc_ratespec *conf,
1221 			       u64 rate64);
1222 
1223 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1224 					  const struct psched_ratecfg *r)
1225 {
1226 	memset(res, 0, sizeof(*res));
1227 
1228 	/* legacy struct tc_ratespec has a 32bit @rate field
1229 	 * Qdisc using 64bit rate should add new attributes
1230 	 * in order to maintain compatibility.
1231 	 */
1232 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1233 
1234 	res->overhead = r->overhead;
1235 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1236 }
1237 
1238 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1239  * The fast path only needs to access filter list and to update stats
1240  */
1241 struct mini_Qdisc {
1242 	struct tcf_proto *filter_list;
1243 	struct tcf_block *block;
1244 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1245 	struct gnet_stats_queue	__percpu *cpu_qstats;
1246 	struct rcu_head rcu;
1247 };
1248 
1249 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1250 						const struct sk_buff *skb)
1251 {
1252 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1253 }
1254 
1255 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1256 {
1257 	this_cpu_inc(miniq->cpu_qstats->drops);
1258 }
1259 
1260 struct mini_Qdisc_pair {
1261 	struct mini_Qdisc miniq1;
1262 	struct mini_Qdisc miniq2;
1263 	struct mini_Qdisc __rcu **p_miniq;
1264 };
1265 
1266 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1267 			  struct tcf_proto *tp_head);
1268 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1269 			  struct mini_Qdisc __rcu **p_miniq);
1270 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1271 				struct tcf_block *block);
1272 
1273 int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));
1274 
1275 #endif
1276