xref: /linux/include/net/sch_generic.h (revision ea4d4b5dddb5121e64f56fd8e0720bd8b447b63d)
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 #include <linux/xarray.h>
23 #include <net/dropreason-qdisc.h>
24 
25 struct Qdisc_ops;
26 struct qdisc_walker;
27 struct tcf_walker;
28 struct module;
29 struct bpf_flow_keys;
30 struct Qdisc;
31 struct netdev_queue;
32 
33 struct qdisc_rate_table {
34 	struct tc_ratespec rate;
35 	u32		data[256];
36 	struct qdisc_rate_table *next;
37 	int		refcnt;
38 };
39 
40 enum qdisc_state_t {
41 	__QDISC_STATE_SCHED,
42 	__QDISC_STATE_DEACTIVATED,
43 	__QDISC_STATE_MISSED,
44 	__QDISC_STATE_DRAINING,
45 };
46 
47 #define QDISC_STATE_MISSED	BIT(__QDISC_STATE_MISSED)
48 #define QDISC_STATE_DRAINING	BIT(__QDISC_STATE_DRAINING)
49 
50 #define QDISC_STATE_NON_EMPTY	(QDISC_STATE_MISSED | \
51 					QDISC_STATE_DRAINING)
52 
53 struct qdisc_size_table {
54 	struct rcu_head		rcu;
55 	struct list_head	list;
56 	struct tc_sizespec	szopts;
57 	int			refcnt;
58 	u16			data[];
59 };
60 
61 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
62 struct qdisc_skb_head {
63 	struct sk_buff	*head;
64 	struct sk_buff	*tail;
65 	__u32		qlen;
66 	spinlock_t	lock;
67 };
68 
69 struct Qdisc {
70 	int 			(*enqueue)(struct sk_buff *skb,
71 					   struct Qdisc *sch,
72 					   struct sk_buff **to_free);
73 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
74 	unsigned int		flags;
75 #define TCQ_F_BUILTIN		1
76 #define TCQ_F_INGRESS		2
77 #define TCQ_F_CAN_BYPASS	4
78 #define TCQ_F_MQROOT		8
79 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
80 				      * q->dev_queue : It can test
81 				      * netif_xmit_frozen_or_stopped() before
82 				      * dequeueing next packet.
83 				      * Its true for MQ/MQPRIO slaves, or non
84 				      * multiqueue device.
85 				      */
86 #define TCQ_F_WARN_NONWC	(1 << 16)
87 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
88 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
89 				      * qdisc_tree_reduce_backlog() should stop.
90 				      */
91 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
92 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
93 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
94 #define TCQ_F_DEQUEUE_DROPS	0x400 /* ->dequeue() can drop packets in q->to_free */
95 
96 	u32			limit;
97 	const struct Qdisc_ops	*ops;
98 	struct qdisc_size_table	__rcu *stab;
99 	struct hlist_node       hash;
100 	u32			handle;
101 	u32			parent;
102 	int			depth;
103 
104 	struct netdev_queue	*dev_queue;
105 
106 	struct net_rate_estimator __rcu *rate_est;
107 	struct gnet_stats_basic_sync __percpu *cpu_bstats;
108 	struct gnet_stats_queue	__percpu *cpu_qstats;
109 	int			pad;
110 	refcount_t		refcnt;
111 
112 	/* Cache line potentially dirtied in dequeue() or __netif_reschedule(). */
113 	__cacheline_group_begin(Qdisc_read_mostly) ____cacheline_aligned;
114 		struct sk_buff_head	gso_skb;
115 		struct Qdisc		*next_sched;
116 		struct sk_buff_head	skb_bad_txq;
117 	__cacheline_group_end(Qdisc_read_mostly);
118 
119 	/* Fields dirtied in dequeue() fast path. */
120 	__cacheline_group_begin(Qdisc_write) ____cacheline_aligned;
121 		struct qdisc_skb_head	q;
122 		unsigned long		state;
123 		struct gnet_stats_basic_sync bstats;
124 		bool			running; /* must be written under qdisc spinlock */
125 
126 		/* Note : we only change qstats.backlog in fast path. */
127 		struct gnet_stats_queue	qstats;
128 
129 		struct sk_buff		*to_free;
130 	__cacheline_group_end(Qdisc_write);
131 
132 
133 	atomic_long_t		defer_count ____cacheline_aligned_in_smp;
134 	struct llist_head	defer_list;
135 
136 	spinlock_t		seqlock;
137 
138 	struct rcu_head		rcu;
139 	netdevice_tracker	dev_tracker;
140 	struct lock_class_key	root_lock_key;
141 	/* private data */
142 	long privdata[] ____cacheline_aligned;
143 };
144 
145 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
146 {
147 	if (qdisc->flags & TCQ_F_BUILTIN)
148 		return;
149 	refcount_inc(&qdisc->refcnt);
150 }
151 
152 static inline bool qdisc_refcount_dec_if_one(struct Qdisc *qdisc)
153 {
154 	if (qdisc->flags & TCQ_F_BUILTIN)
155 		return true;
156 	return refcount_dec_if_one(&qdisc->refcnt);
157 }
158 
159 /* Intended to be used by unlocked users, when concurrent qdisc release is
160  * possible.
161  */
162 
163 static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
164 {
165 	if (qdisc->flags & TCQ_F_BUILTIN)
166 		return qdisc;
167 	if (refcount_inc_not_zero(&qdisc->refcnt))
168 		return qdisc;
169 	return NULL;
170 }
171 
172 /* For !TCQ_F_NOLOCK qdisc: callers must either call this within a qdisc
173  * root_lock section, or provide their own memory barriers -- ordering
174  * against qdisc_run_begin/end() atomic bit operations.
175  */
176 static inline bool qdisc_is_running(struct Qdisc *qdisc)
177 {
178 	if (qdisc->flags & TCQ_F_NOLOCK)
179 		return spin_is_locked(&qdisc->seqlock);
180 	return READ_ONCE(qdisc->running);
181 }
182 
183 static inline bool nolock_qdisc_is_empty(const struct Qdisc *qdisc)
184 {
185 	return !(READ_ONCE(qdisc->state) & QDISC_STATE_NON_EMPTY);
186 }
187 
188 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
189 {
190 	return q->flags & TCQ_F_CPUSTATS;
191 }
192 
193 static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
194 {
195 	if (qdisc_is_percpu_stats(qdisc))
196 		return nolock_qdisc_is_empty(qdisc);
197 	return !READ_ONCE(qdisc->q.qlen);
198 }
199 
200 /* For !TCQ_F_NOLOCK qdisc, qdisc_run_begin/end() must be invoked with
201  * the qdisc root lock acquired.
202  */
203 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
204 {
205 	if (qdisc->flags & TCQ_F_NOLOCK) {
206 		if (spin_trylock(&qdisc->seqlock))
207 			return true;
208 
209 		/* No need to insist if the MISSED flag was already set.
210 		 * Note that test_and_set_bit() also gives us memory ordering
211 		 * guarantees wrt potential earlier enqueue() and below
212 		 * spin_trylock(), both of which are necessary to prevent races
213 		 */
214 		if (test_and_set_bit(__QDISC_STATE_MISSED, &qdisc->state))
215 			return false;
216 
217 		/* Try to take the lock again to make sure that we will either
218 		 * grab it or the CPU that still has it will see MISSED set
219 		 * when testing it in qdisc_run_end()
220 		 */
221 		return spin_trylock(&qdisc->seqlock);
222 	}
223 	if (READ_ONCE(qdisc->running))
224 		return false;
225 	WRITE_ONCE(qdisc->running, true);
226 	return true;
227 }
228 
229 static inline struct sk_buff *qdisc_run_end(struct Qdisc *qdisc)
230 {
231 	struct sk_buff *to_free = NULL;
232 
233 	if (qdisc->flags & TCQ_F_NOLOCK) {
234 		spin_unlock(&qdisc->seqlock);
235 
236 		/* spin_unlock() only has store-release semantic. The unlock
237 		 * and test_bit() ordering is a store-load ordering, so a full
238 		 * memory barrier is needed here.
239 		 */
240 		smp_mb();
241 
242 		if (unlikely(test_bit(__QDISC_STATE_MISSED,
243 				      &qdisc->state)))
244 			__netif_schedule(qdisc);
245 		return NULL;
246 	}
247 
248 	if (qdisc->flags & TCQ_F_DEQUEUE_DROPS) {
249 		to_free = qdisc->to_free;
250 		if (to_free)
251 			qdisc->to_free = NULL;
252 	}
253 	WRITE_ONCE(qdisc->running, false);
254 	return to_free;
255 }
256 
257 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
258 {
259 	return qdisc->flags & TCQ_F_ONETXQUEUE;
260 }
261 
262 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
263 {
264 	return netdev_queue_dql_avail(txq);
265 }
266 
267 struct Qdisc_class_ops {
268 	unsigned int		flags;
269 	/* Child qdisc manipulation */
270 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
271 	int			(*graft)(struct Qdisc *, unsigned long cl,
272 					struct Qdisc *, struct Qdisc **,
273 					struct netlink_ext_ack *extack);
274 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
275 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
276 
277 	/* Class manipulation routines */
278 	unsigned long		(*find)(struct Qdisc *, u32 classid);
279 	int			(*change)(struct Qdisc *, u32, u32,
280 					struct nlattr **, unsigned long *,
281 					struct netlink_ext_ack *);
282 	int			(*delete)(struct Qdisc *, unsigned long,
283 					  struct netlink_ext_ack *);
284 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
285 
286 	/* Filter manipulation */
287 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
288 					     unsigned long arg,
289 					     struct netlink_ext_ack *extack);
290 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
291 					u32 classid);
292 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
293 
294 	/* rtnetlink specific */
295 	int			(*dump)(struct Qdisc *, unsigned long,
296 					struct sk_buff *skb, struct tcmsg*);
297 	int			(*dump_stats)(struct Qdisc *, unsigned long,
298 					struct gnet_dump *);
299 };
300 
301 /* Qdisc_class_ops flag values */
302 
303 /* Implements API that doesn't require rtnl lock */
304 enum qdisc_class_ops_flags {
305 	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
306 };
307 
308 struct Qdisc_ops {
309 	struct Qdisc_ops	*next;
310 	const struct Qdisc_class_ops	*cl_ops;
311 	char			id[IFNAMSIZ];
312 	int			priv_size;
313 	unsigned int		static_flags;
314 
315 	int 			(*enqueue)(struct sk_buff *skb,
316 					   struct Qdisc *sch,
317 					   struct sk_buff **to_free);
318 	struct sk_buff *	(*dequeue)(struct Qdisc *);
319 	struct sk_buff *	(*peek)(struct Qdisc *);
320 
321 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
322 					struct netlink_ext_ack *extack);
323 	void			(*reset)(struct Qdisc *);
324 	void			(*destroy)(struct Qdisc *);
325 	int			(*change)(struct Qdisc *sch,
326 					  struct nlattr *arg,
327 					  struct netlink_ext_ack *extack);
328 	void			(*attach)(struct Qdisc *sch);
329 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
330 	void			(*change_real_num_tx)(struct Qdisc *sch,
331 						      unsigned int new_real_tx);
332 
333 	int			(*dump)(struct Qdisc *, struct sk_buff *);
334 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
335 
336 	void			(*ingress_block_set)(struct Qdisc *sch,
337 						     u32 block_index);
338 	void			(*egress_block_set)(struct Qdisc *sch,
339 						    u32 block_index);
340 	u32			(*ingress_block_get)(struct Qdisc *sch);
341 	u32			(*egress_block_get)(struct Qdisc *sch);
342 
343 	struct module		*owner;
344 };
345 
346 struct tcf_result {
347 	union {
348 		struct {
349 			unsigned long	class;
350 			u32		classid;
351 		};
352 		const struct tcf_proto *goto_tp;
353 	};
354 };
355 
356 struct tcf_chain;
357 
358 struct tcf_proto_ops {
359 	struct list_head	head;
360 	char			kind[IFNAMSIZ];
361 
362 	int			(*classify)(struct sk_buff *,
363 					    const struct tcf_proto *,
364 					    struct tcf_result *);
365 	int			(*init)(struct tcf_proto*);
366 	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
367 					   struct netlink_ext_ack *extack);
368 
369 	void*			(*get)(struct tcf_proto*, u32 handle);
370 	void			(*put)(struct tcf_proto *tp, void *f);
371 	int			(*change)(struct net *net, struct sk_buff *,
372 					struct tcf_proto*, unsigned long,
373 					u32 handle, struct nlattr **,
374 					void **, u32,
375 					struct netlink_ext_ack *);
376 	int			(*delete)(struct tcf_proto *tp, void *arg,
377 					  bool *last, bool rtnl_held,
378 					  struct netlink_ext_ack *);
379 	bool			(*delete_empty)(struct tcf_proto *tp);
380 	void			(*walk)(struct tcf_proto *tp,
381 					struct tcf_walker *arg, bool rtnl_held);
382 	int			(*reoffload)(struct tcf_proto *tp, bool add,
383 					     flow_setup_cb_t *cb, void *cb_priv,
384 					     struct netlink_ext_ack *extack);
385 	void			(*hw_add)(struct tcf_proto *tp,
386 					  void *type_data);
387 	void			(*hw_del)(struct tcf_proto *tp,
388 					  void *type_data);
389 	void			(*bind_class)(void *, u32, unsigned long,
390 					      void *, unsigned long);
391 	void *			(*tmplt_create)(struct net *net,
392 						struct tcf_chain *chain,
393 						struct nlattr **tca,
394 						struct netlink_ext_ack *extack);
395 	void			(*tmplt_destroy)(void *tmplt_priv);
396 	void			(*tmplt_reoffload)(struct tcf_chain *chain,
397 						   bool add,
398 						   flow_setup_cb_t *cb,
399 						   void *cb_priv);
400 	struct tcf_exts *	(*get_exts)(const struct tcf_proto *tp,
401 					    u32 handle);
402 
403 	/* rtnetlink specific */
404 	int			(*dump)(struct net*, struct tcf_proto*, void *,
405 					struct sk_buff *skb, struct tcmsg*,
406 					bool);
407 	int			(*terse_dump)(struct net *net,
408 					      struct tcf_proto *tp, void *fh,
409 					      struct sk_buff *skb,
410 					      struct tcmsg *t, bool rtnl_held);
411 	int			(*tmplt_dump)(struct sk_buff *skb,
412 					      struct net *net,
413 					      void *tmplt_priv);
414 
415 	struct module		*owner;
416 	int			flags;
417 };
418 
419 /* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
420  * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
421  * conditions can occur when filters are inserted/deleted simultaneously.
422  */
423 enum tcf_proto_ops_flags {
424 	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
425 };
426 
427 struct tcf_proto {
428 	/* Fast access part */
429 	struct tcf_proto __rcu	*next;
430 	void __rcu		*root;
431 
432 	/* called under RCU BH lock*/
433 	int			(*classify)(struct sk_buff *,
434 					    const struct tcf_proto *,
435 					    struct tcf_result *);
436 	__be16			protocol;
437 
438 	/* All the rest */
439 	u32			prio;
440 	void			*data;
441 	const struct tcf_proto_ops	*ops;
442 	struct tcf_chain	*chain;
443 	/* Lock protects tcf_proto shared state and can be used by unlocked
444 	 * classifiers to protect their private data.
445 	 */
446 	spinlock_t		lock;
447 	bool			deleting;
448 	bool			counted;
449 	bool			usesw;
450 	refcount_t		refcnt;
451 	struct rcu_head		rcu;
452 	struct hlist_node	destroy_ht_node;
453 };
454 
455 struct qdisc_skb_cb {
456 	unsigned int		pkt_len;
457 	u16			pkt_segs;
458 	u16			tc_classid;
459 #define QDISC_CB_PRIV_LEN 20
460 	unsigned char		data[QDISC_CB_PRIV_LEN];
461 
462 	u16			slave_dev_queue_mapping;
463 	u8			post_ct:1;
464 	u8			post_ct_snat:1;
465 	u8			post_ct_dnat:1;
466 };
467 
468 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
469 
470 struct tcf_chain {
471 	/* Protects filter_chain. */
472 	struct mutex filter_chain_lock;
473 	struct tcf_proto __rcu *filter_chain;
474 	struct list_head list;
475 	struct tcf_block *block;
476 	u32 index; /* chain index */
477 	unsigned int refcnt;
478 	unsigned int action_refcnt;
479 	bool explicitly_created;
480 	bool flushing;
481 	const struct tcf_proto_ops *tmplt_ops;
482 	void *tmplt_priv;
483 	struct rcu_head rcu;
484 };
485 
486 struct tcf_block {
487 	struct xarray ports; /* datapath accessible */
488 	/* Lock protects tcf_block and lifetime-management data of chains
489 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
490 	 */
491 	struct mutex lock;
492 	struct list_head chain_list;
493 	u32 index; /* block index for shared blocks */
494 	u32 classid; /* which class this block belongs to */
495 	refcount_t refcnt;
496 	struct net *net;
497 	struct Qdisc *q;
498 	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
499 	struct flow_block flow_block;
500 	struct list_head owner_list;
501 	bool keep_dst;
502 	atomic_t useswcnt;
503 	atomic_t offloadcnt; /* Number of oddloaded filters */
504 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
505 	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
506 	struct {
507 		struct tcf_chain *chain;
508 		struct list_head filter_chain_list;
509 	} chain0;
510 	struct rcu_head rcu;
511 	DECLARE_HASHTABLE(proto_destroy_ht, 7);
512 	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
513 };
514 
515 struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index);
516 
517 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
518 {
519 	return lockdep_is_held(&chain->filter_chain_lock);
520 }
521 
522 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
523 {
524 	return lockdep_is_held(&tp->lock);
525 }
526 
527 #define tcf_chain_dereference(p, chain)					\
528 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
529 
530 #define tcf_proto_dereference(p, tp)					\
531 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
532 
533 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
534 {
535 	struct qdisc_skb_cb *qcb;
536 
537 	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
538 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
539 }
540 
541 static inline int qdisc_qlen(const struct Qdisc *q)
542 {
543 	return q->q.qlen;
544 }
545 
546 static inline int qdisc_qlen_lockless(const struct Qdisc *q)
547 {
548 	return READ_ONCE(q->q.qlen);
549 }
550 
551 static inline void qdisc_qlen_inc(struct Qdisc *q)
552 {
553 	WRITE_ONCE(q->q.qlen, q->q.qlen + 1);
554 }
555 
556 static inline void qdisc_qlen_dec(struct Qdisc *q)
557 {
558 	WRITE_ONCE(q->q.qlen, q->q.qlen - 1);
559 }
560 
561 static inline int qdisc_qlen_sum(const struct Qdisc *q)
562 {
563 	__u32 qlen = q->qstats.qlen;
564 	int i;
565 
566 	if (qdisc_is_percpu_stats(q)) {
567 		for_each_possible_cpu(i)
568 			qlen += READ_ONCE(per_cpu_ptr(q->cpu_qstats, i)->qlen);
569 	} else {
570 		qlen += qdisc_qlen_lockless(q);
571 	}
572 
573 	return qlen;
574 }
575 
576 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
577 {
578 	return (struct qdisc_skb_cb *)skb->cb;
579 }
580 
581 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
582 {
583 	return &qdisc->q.lock;
584 }
585 
586 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
587 {
588 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
589 
590 	return q;
591 }
592 
593 static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
594 {
595 	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
596 }
597 
598 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
599 {
600 	return rcu_dereference_rtnl(qdisc->dev_queue->qdisc_sleeping);
601 }
602 
603 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
604 {
605 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
606 
607 	ASSERT_RTNL();
608 	return qdisc_lock(root);
609 }
610 
611 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
612 {
613 	return qdisc->dev_queue->dev;
614 }
615 
616 static inline void sch_tree_lock(struct Qdisc *q)
617 {
618 	if (q->flags & TCQ_F_MQROOT)
619 		spin_lock_bh(qdisc_lock(q));
620 	else
621 		spin_lock_bh(qdisc_root_sleeping_lock(q));
622 }
623 
624 static inline void sch_tree_unlock(struct Qdisc *q)
625 {
626 	if (q->flags & TCQ_F_MQROOT)
627 		spin_unlock_bh(qdisc_lock(q));
628 	else
629 		spin_unlock_bh(qdisc_root_sleeping_lock(q));
630 }
631 
632 extern struct Qdisc noop_qdisc;
633 extern struct Qdisc_ops noop_qdisc_ops;
634 extern struct Qdisc_ops pfifo_fast_ops;
635 extern const u8 sch_default_prio2band[TC_PRIO_MAX + 1];
636 extern struct Qdisc_ops mq_qdisc_ops;
637 extern struct Qdisc_ops noqueue_qdisc_ops;
638 extern const struct Qdisc_ops *default_qdisc_ops;
639 static inline const struct Qdisc_ops *
640 get_default_qdisc_ops(const struct net_device *dev, int ntx)
641 {
642 	return ntx < dev->real_num_tx_queues ?
643 			default_qdisc_ops : &pfifo_fast_ops;
644 }
645 
646 struct Qdisc_class_common {
647 	u32			classid;
648 	unsigned int		filter_cnt;
649 	struct hlist_node	hnode;
650 };
651 
652 struct Qdisc_class_hash {
653 	struct hlist_head	*hash;
654 	unsigned int		hashsize;
655 	unsigned int		hashmask;
656 	unsigned int		hashelems;
657 };
658 
659 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
660 {
661 	id ^= id >> 8;
662 	id ^= id >> 4;
663 	return id & mask;
664 }
665 
666 static inline struct Qdisc_class_common *
667 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
668 {
669 	struct Qdisc_class_common *cl;
670 	unsigned int h;
671 
672 	if (!id)
673 		return NULL;
674 
675 	h = qdisc_class_hash(id, hash->hashmask);
676 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
677 		if (cl->classid == id)
678 			return cl;
679 	}
680 	return NULL;
681 }
682 
683 static inline bool qdisc_class_in_use(const struct Qdisc_class_common *cl)
684 {
685 	return cl->filter_cnt > 0;
686 }
687 
688 static inline void qdisc_class_get(struct Qdisc_class_common *cl)
689 {
690 	unsigned int res;
691 
692 	if (check_add_overflow(cl->filter_cnt, 1, &res))
693 		WARN(1, "Qdisc class overflow");
694 
695 	cl->filter_cnt = res;
696 }
697 
698 static inline void qdisc_class_put(struct Qdisc_class_common *cl)
699 {
700 	unsigned int res;
701 
702 	if (check_sub_overflow(cl->filter_cnt, 1, &res))
703 		WARN(1, "Qdisc class underflow");
704 
705 	cl->filter_cnt = res;
706 }
707 
708 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
709 {
710 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
711 
712 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
713 }
714 
715 int qdisc_class_hash_init(struct Qdisc_class_hash *);
716 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
717 			     struct Qdisc_class_common *);
718 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
719 			     struct Qdisc_class_common *);
720 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
721 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
722 
723 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
724 void dev_qdisc_change_real_num_tx(struct net_device *dev,
725 				  unsigned int new_real_tx);
726 void dev_init_scheduler(struct net_device *dev);
727 void dev_shutdown(struct net_device *dev);
728 void dev_activate(struct net_device *dev);
729 void dev_deactivate(struct net_device *dev, bool reset_needed);
730 void dev_deactivate_many(struct list_head *head, bool reset_needed);
731 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
732 			      struct Qdisc *qdisc);
733 void qdisc_reset(struct Qdisc *qdisc);
734 void qdisc_destroy(struct Qdisc *qdisc);
735 void qdisc_put(struct Qdisc *qdisc);
736 void qdisc_put_unlocked(struct Qdisc *qdisc);
737 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
738 
739 static inline void dev_reset_queue(struct net_device *dev,
740 				   struct netdev_queue *dev_queue,
741 				   void *_unused)
742 {
743 	struct Qdisc *qdisc;
744 	bool nolock;
745 
746 	qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
747 	if (!qdisc)
748 		return;
749 
750 	nolock = qdisc->flags & TCQ_F_NOLOCK;
751 
752 	if (nolock)
753 		spin_lock_bh(&qdisc->seqlock);
754 	spin_lock_bh(qdisc_lock(qdisc));
755 
756 	qdisc_reset(qdisc);
757 
758 	spin_unlock_bh(qdisc_lock(qdisc));
759 	if (nolock) {
760 		clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
761 		clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);
762 		spin_unlock_bh(&qdisc->seqlock);
763 	}
764 }
765 
766 #ifdef CONFIG_NET_SCHED
767 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
768 			      void *type_data);
769 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
770 				struct Qdisc *new, struct Qdisc *old,
771 				enum tc_setup_type type, void *type_data,
772 				struct netlink_ext_ack *extack);
773 #else
774 static inline int
775 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
776 			  void *type_data)
777 {
778 	q->flags &= ~TCQ_F_OFFLOADED;
779 	return 0;
780 }
781 
782 static inline void
783 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
784 			   struct Qdisc *new, struct Qdisc *old,
785 			   enum tc_setup_type type, void *type_data,
786 			   struct netlink_ext_ack *extack)
787 {
788 }
789 #endif
790 void qdisc_offload_query_caps(struct net_device *dev,
791 			      enum tc_setup_type type,
792 			      void *caps, size_t caps_len);
793 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
794 			  const struct Qdisc_ops *ops,
795 			  struct netlink_ext_ack *extack);
796 void qdisc_free_rcu(struct Qdisc *qdisc);
797 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
798 				const struct Qdisc_ops *ops, u32 parentid,
799 				struct netlink_ext_ack *extack);
800 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
801 			       const struct qdisc_size_table *stab);
802 int skb_do_redirect(struct sk_buff *);
803 
804 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
805 {
806 #ifdef CONFIG_NET_XGRESS
807 	return skb->tc_at_ingress;
808 #else
809 	return false;
810 #endif
811 }
812 
813 static inline bool skb_at_tc_egress(const struct sk_buff *skb)
814 {
815 #ifdef CONFIG_NET_EGRESS
816 	return skb->nf_skip_egress && !skb_at_tc_ingress(skb);
817 #else
818 	return false;
819 #endif
820 }
821 
822 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
823 {
824 #ifdef CONFIG_NET_CLS_ACT
825 	if (skb->tc_skip_classify) {
826 		skb->tc_skip_classify = 0;
827 		return true;
828 	}
829 #endif
830 	return false;
831 }
832 
833 /* Reset all TX qdiscs greater than index of a device.  */
834 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
835 {
836 	struct Qdisc *qdisc;
837 	bool nolock;
838 
839 	for (; i < dev->num_tx_queues; i++) {
840 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
841 		if (qdisc) {
842 			nolock = qdisc->flags & TCQ_F_NOLOCK;
843 
844 			if (nolock)
845 				spin_lock_bh(&qdisc->seqlock);
846 			spin_lock_bh(qdisc_lock(qdisc));
847 			qdisc_reset(qdisc);
848 			spin_unlock_bh(qdisc_lock(qdisc));
849 			if (nolock) {
850 				clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
851 				clear_bit(__QDISC_STATE_DRAINING, &qdisc->state);
852 				spin_unlock_bh(&qdisc->seqlock);
853 			}
854 		}
855 	}
856 }
857 
858 /* Are all TX queues of the device empty?  */
859 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
860 {
861 	unsigned int i;
862 
863 	rcu_read_lock();
864 	for (i = 0; i < dev->num_tx_queues; i++) {
865 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
866 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
867 
868 		if (!qdisc_is_empty(q)) {
869 			rcu_read_unlock();
870 			return false;
871 		}
872 	}
873 	rcu_read_unlock();
874 	return true;
875 }
876 
877 /* Are any of the TX qdiscs changing?  */
878 static inline bool qdisc_tx_changing(const struct net_device *dev)
879 {
880 	unsigned int i;
881 
882 	for (i = 0; i < dev->num_tx_queues; i++) {
883 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
884 
885 		if (rcu_access_pointer(txq->qdisc) !=
886 		    rcu_access_pointer(txq->qdisc_sleeping))
887 			return true;
888 	}
889 	return false;
890 }
891 
892 /* "noqueue" qdisc identified by not having any enqueue, see noqueue_init() */
893 static inline bool qdisc_txq_has_no_queue(const struct netdev_queue *txq)
894 {
895 	struct Qdisc *qdisc = rcu_access_pointer(txq->qdisc);
896 
897 	return qdisc->enqueue == NULL;
898 }
899 
900 /* Is the device using the noop qdisc on all queues?  */
901 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
902 {
903 	unsigned int i;
904 
905 	for (i = 0; i < dev->num_tx_queues; i++) {
906 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
907 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
908 			return false;
909 	}
910 	return true;
911 }
912 
913 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
914 {
915 	return qdisc_skb_cb(skb)->pkt_len;
916 }
917 
918 static inline unsigned int qdisc_pkt_segs(const struct sk_buff *skb)
919 {
920 	u32 pkt_segs = qdisc_skb_cb(skb)->pkt_segs;
921 
922 	DEBUG_NET_WARN_ON_ONCE(pkt_segs !=
923 			(skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1));
924 	return pkt_segs;
925 }
926 
927 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
928 enum net_xmit_qdisc_t {
929 	__NET_XMIT_STOLEN = 0x00010000,
930 	__NET_XMIT_BYPASS = 0x00020000,
931 };
932 
933 #ifdef CONFIG_NET_CLS_ACT
934 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
935 #else
936 #define net_xmit_drop_count(e)	(1)
937 #endif
938 
939 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
940 					   const struct Qdisc *sch)
941 {
942 #ifdef CONFIG_NET_SCHED
943 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
944 
945 	if (stab)
946 		__qdisc_calculate_pkt_len(skb, stab);
947 #endif
948 }
949 
950 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
951 				struct sk_buff **to_free)
952 {
953 	return sch->enqueue(skb, sch, to_free);
954 }
955 
956 static inline void _bstats_update(struct gnet_stats_basic_sync *bstats,
957 				  __u64 bytes, __u64 packets)
958 {
959 	u64_stats_update_begin(&bstats->syncp);
960 	u64_stats_add(&bstats->bytes, bytes);
961 	u64_stats_add(&bstats->packets, packets);
962 	u64_stats_update_end(&bstats->syncp);
963 }
964 
965 static inline void _bstats_set(struct gnet_stats_basic_sync *bstats,
966 			       u64 bytes, u64 packets)
967 {
968 	u64_stats_update_begin(&bstats->syncp);
969 	u64_stats_set(&bstats->bytes, bytes);
970 	u64_stats_set(&bstats->packets, packets);
971 	u64_stats_update_end(&bstats->syncp);
972 }
973 
974 static inline void bstats_update(struct gnet_stats_basic_sync *bstats,
975 				 const struct sk_buff *skb)
976 {
977 	_bstats_update(bstats, qdisc_pkt_len(skb), qdisc_pkt_segs(skb));
978 }
979 
980 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
981 					   const struct sk_buff *skb)
982 {
983 	bstats_update(this_cpu_ptr(sch->cpu_bstats), skb);
984 }
985 
986 static inline void qdisc_bstats_update(struct Qdisc *sch,
987 				       const struct sk_buff *skb)
988 {
989 	bstats_update(&sch->bstats, skb);
990 }
991 
992 static inline void qstats_backlog_sub(struct Qdisc *sch, u32 val)
993 {
994 	WRITE_ONCE(sch->qstats.backlog, sch->qstats.backlog - val);
995 }
996 
997 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
998 					    const struct sk_buff *skb)
999 {
1000 	qstats_backlog_sub(sch, qdisc_pkt_len(skb));
1001 }
1002 
1003 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
1004 						const struct sk_buff *skb)
1005 {
1006 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
1007 }
1008 
1009 static inline void qstats_backlog_add(struct Qdisc *sch, u32 val)
1010 {
1011 	WRITE_ONCE(sch->qstats.backlog, sch->qstats.backlog + val);
1012 }
1013 
1014 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
1015 					    const struct sk_buff *skb)
1016 {
1017 	qstats_backlog_add(sch, qdisc_pkt_len(skb));
1018 }
1019 
1020 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
1021 						const struct sk_buff *skb)
1022 {
1023 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
1024 }
1025 
1026 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
1027 {
1028 	this_cpu_inc(sch->cpu_qstats->qlen);
1029 }
1030 
1031 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
1032 {
1033 	this_cpu_dec(sch->cpu_qstats->qlen);
1034 }
1035 
1036 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
1037 {
1038 	this_cpu_inc(sch->cpu_qstats->requeues);
1039 }
1040 
1041 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
1042 {
1043 	WRITE_ONCE(sch->qstats.drops, sch->qstats.drops + count);
1044 }
1045 
1046 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
1047 {
1048 	WRITE_ONCE(qstats->drops, qstats->drops + 1);
1049 }
1050 
1051 static inline void qstats_cpu_drop_inc(struct gnet_stats_queue __percpu *qstats)
1052 {
1053 	this_cpu_inc(qstats->drops);
1054 }
1055 
1056 static inline void qstats_cpu_overlimit_inc(struct gnet_stats_queue __percpu *qstats)
1057 {
1058 	this_cpu_inc(qstats->overlimits);
1059 }
1060 
1061 static inline void qdisc_qstats_drop(struct Qdisc *sch)
1062 {
1063 	qstats_drop_inc(&sch->qstats);
1064 }
1065 
1066 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
1067 {
1068 	this_cpu_inc(sch->cpu_qstats->drops);
1069 }
1070 
1071 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
1072 {
1073 	WRITE_ONCE(sch->qstats.overlimits, sch->qstats.overlimits + 1);
1074 }
1075 
1076 static inline int qdisc_qstats_copy(struct gnet_dump *d, const struct Qdisc *sch)
1077 {
1078 	__u32 qlen = qdisc_qlen_sum(sch);
1079 
1080 	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
1081 }
1082 
1083 static inline void qdisc_qstats_qlen_backlog(const struct Qdisc *sch,
1084 					     u32 *qlen, u32 *backlog)
1085 {
1086 	struct gnet_stats_queue qstats = { 0 };
1087 
1088 	gnet_stats_add_queue(&qstats, sch->cpu_qstats, &sch->qstats);
1089 	*qlen = qstats.qlen + qdisc_qlen_lockless(sch);
1090 	*backlog = qstats.backlog;
1091 }
1092 
1093 static inline void qdisc_purge_queue(struct Qdisc *sch)
1094 {
1095 	__u32 qlen, backlog;
1096 
1097 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
1098 	qdisc_reset(sch);
1099 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
1100 }
1101 
1102 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
1103 					struct qdisc_skb_head *qh)
1104 {
1105 	struct sk_buff *last = qh->tail;
1106 
1107 	if (last) {
1108 		skb->next = NULL;
1109 		last->next = skb;
1110 		qh->tail = skb;
1111 	} else {
1112 		qh->tail = skb;
1113 		qh->head = skb;
1114 	}
1115 	WRITE_ONCE(qh->qlen, qh->qlen + 1);
1116 }
1117 
1118 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
1119 {
1120 	__qdisc_enqueue_tail(skb, &sch->q);
1121 	qdisc_qstats_backlog_inc(sch, skb);
1122 	return NET_XMIT_SUCCESS;
1123 }
1124 
1125 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
1126 					struct qdisc_skb_head *qh)
1127 {
1128 	skb->next = qh->head;
1129 
1130 	if (!qh->head)
1131 		qh->tail = skb;
1132 	qh->head = skb;
1133 	WRITE_ONCE(qh->qlen, qh->qlen + 1);
1134 }
1135 
1136 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
1137 {
1138 	struct sk_buff *skb = qh->head;
1139 
1140 	if (likely(skb != NULL)) {
1141 		qh->head = skb->next;
1142 		WRITE_ONCE(qh->qlen, qh->qlen - 1);
1143 		if (qh->head == NULL)
1144 			qh->tail = NULL;
1145 		skb->next = NULL;
1146 	}
1147 
1148 	return skb;
1149 }
1150 
1151 static inline struct sk_buff *qdisc_dequeue_internal(struct Qdisc *sch, bool direct)
1152 {
1153 	struct sk_buff *skb;
1154 
1155 	skb = __skb_dequeue(&sch->gso_skb);
1156 	if (skb) {
1157 		qdisc_qlen_dec(sch);
1158 		qdisc_qstats_backlog_dec(sch, skb);
1159 		return skb;
1160 	}
1161 	if (direct) {
1162 		skb = __qdisc_dequeue_head(&sch->q);
1163 		if (skb)
1164 			qdisc_qstats_backlog_dec(sch, skb);
1165 		return skb;
1166 	} else {
1167 		return sch->dequeue(sch);
1168 	}
1169 }
1170 
1171 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
1172 {
1173 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
1174 
1175 	if (likely(skb != NULL)) {
1176 		qdisc_qstats_backlog_dec(sch, skb);
1177 		qdisc_bstats_update(sch, skb);
1178 	}
1179 
1180 	return skb;
1181 }
1182 
1183 struct tc_skb_cb {
1184 	struct qdisc_skb_cb qdisc_cb;
1185 	u32 drop_reason;
1186 
1187 	u16 zone; /* Only valid if qdisc_skb_cb(skb)->post_ct = true */
1188 	u16 mru;
1189 };
1190 
1191 static inline struct tc_skb_cb *tc_skb_cb(const struct sk_buff *skb)
1192 {
1193 	struct tc_skb_cb *cb = (struct tc_skb_cb *)skb->cb;
1194 
1195 	BUILD_BUG_ON(sizeof(*cb) > sizeof_field(struct sk_buff, cb));
1196 	return cb;
1197 }
1198 
1199 /* TC classifier accessors - use enum skb_drop_reason */
1200 static inline enum skb_drop_reason
1201 tcf_get_drop_reason(const struct sk_buff *skb)
1202 {
1203 	return (enum skb_drop_reason)tc_skb_cb(skb)->drop_reason;
1204 }
1205 
1206 static inline void tcf_set_drop_reason(const struct sk_buff *skb,
1207 				       enum skb_drop_reason reason)
1208 {
1209 	tc_skb_cb(skb)->drop_reason = (enum qdisc_drop_reason)reason;
1210 }
1211 
1212 /* Qdisc accessors - use enum qdisc_drop_reason */
1213 static inline enum qdisc_drop_reason
1214 tcf_get_qdisc_drop_reason(const struct sk_buff *skb)
1215 {
1216 	return tc_skb_cb(skb)->drop_reason;
1217 }
1218 
1219 static inline void tcf_set_qdisc_drop_reason(const struct sk_buff *skb,
1220 					     enum qdisc_drop_reason reason)
1221 {
1222 	tc_skb_cb(skb)->drop_reason = reason;
1223 }
1224 
1225 void __tcf_kfree_skb_list(struct sk_buff *skb, struct Qdisc *q,
1226 			  struct netdev_queue *txq, struct net_device *dev);
1227 
1228 static inline void tcf_kfree_skb_list(struct sk_buff *skb, struct Qdisc *q,
1229 				      struct netdev_queue *txq,
1230 				      struct net_device *dev)
1231 {
1232 	if (unlikely(skb))
1233 		__tcf_kfree_skb_list(skb, q, txq, dev);
1234 }
1235 
1236 static inline void qdisc_dequeue_drop(struct Qdisc *q, struct sk_buff *skb,
1237 				      enum qdisc_drop_reason reason)
1238 {
1239 	struct Qdisc *root;
1240 
1241 	DEBUG_NET_WARN_ON_ONCE(!(q->flags & TCQ_F_DEQUEUE_DROPS));
1242 	DEBUG_NET_WARN_ON_ONCE(q->flags & TCQ_F_NOLOCK);
1243 
1244 	rcu_read_lock();
1245 	root = qdisc_root_sleeping(q);
1246 
1247 	if (root->flags & TCQ_F_DEQUEUE_DROPS) {
1248 		tcf_set_qdisc_drop_reason(skb, reason);
1249 		skb->next = root->to_free;
1250 		root->to_free = skb;
1251 	} else {
1252 		kfree_skb_reason(skb, (enum skb_drop_reason)reason);
1253 	}
1254 	rcu_read_unlock();
1255 }
1256 
1257 /* Instead of calling kfree_skb() while root qdisc lock is held,
1258  * queue the skb for future freeing at end of __dev_xmit_skb()
1259  */
1260 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1261 {
1262 	skb->next = *to_free;
1263 	*to_free = skb;
1264 }
1265 
1266 static inline void __qdisc_drop_all(struct sk_buff *skb,
1267 				    struct sk_buff **to_free)
1268 {
1269 	if (skb->prev)
1270 		skb->prev->next = *to_free;
1271 	else
1272 		skb->next = *to_free;
1273 	*to_free = skb;
1274 }
1275 
1276 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1277 						   struct qdisc_skb_head *qh,
1278 						   struct sk_buff **to_free)
1279 {
1280 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1281 
1282 	if (likely(skb != NULL)) {
1283 		unsigned int len = qdisc_pkt_len(skb);
1284 
1285 		qdisc_qstats_backlog_dec(sch, skb);
1286 		__qdisc_drop(skb, to_free);
1287 		return len;
1288 	}
1289 
1290 	return 0;
1291 }
1292 
1293 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1294 {
1295 	const struct qdisc_skb_head *qh = &sch->q;
1296 
1297 	return qh->head;
1298 }
1299 
1300 /* generic pseudo peek method for non-work-conserving qdisc */
1301 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1302 {
1303 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1304 
1305 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1306 	if (!skb) {
1307 		skb = sch->dequeue(sch);
1308 
1309 		if (skb) {
1310 			__skb_queue_head(&sch->gso_skb, skb);
1311 			/* it's still part of the queue */
1312 			qdisc_qstats_backlog_inc(sch, skb);
1313 			qdisc_qlen_inc(sch);
1314 		}
1315 	}
1316 
1317 	return skb;
1318 }
1319 
1320 static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1321 						 struct sk_buff *skb)
1322 {
1323 	if (qdisc_is_percpu_stats(sch)) {
1324 		qdisc_qstats_cpu_backlog_dec(sch, skb);
1325 		qdisc_bstats_cpu_update(sch, skb);
1326 		qdisc_qstats_cpu_qlen_dec(sch);
1327 	} else {
1328 		qdisc_qstats_backlog_dec(sch, skb);
1329 		qdisc_bstats_update(sch, skb);
1330 		qdisc_qlen_dec(sch);
1331 	}
1332 }
1333 
1334 static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1335 						 unsigned int pkt_len)
1336 {
1337 	if (qdisc_is_percpu_stats(sch)) {
1338 		qdisc_qstats_cpu_qlen_inc(sch);
1339 		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1340 	} else {
1341 		qstats_backlog_add(sch, pkt_len);
1342 		qdisc_qlen_inc(sch);
1343 	}
1344 }
1345 
1346 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1347 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1348 {
1349 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1350 
1351 	if (skb) {
1352 		skb = __skb_dequeue(&sch->gso_skb);
1353 		if (qdisc_is_percpu_stats(sch)) {
1354 			qdisc_qstats_cpu_backlog_dec(sch, skb);
1355 			qdisc_qstats_cpu_qlen_dec(sch);
1356 		} else {
1357 			qdisc_qstats_backlog_dec(sch, skb);
1358 			qdisc_qlen_dec(sch);
1359 		}
1360 	} else {
1361 		skb = sch->dequeue(sch);
1362 	}
1363 
1364 	return skb;
1365 }
1366 
1367 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1368 {
1369 	/*
1370 	 * We do not know the backlog in bytes of this list, it
1371 	 * is up to the caller to correct it
1372 	 */
1373 	ASSERT_RTNL();
1374 	if (qh->qlen) {
1375 		rtnl_kfree_skbs(qh->head, qh->tail);
1376 
1377 		qh->head = NULL;
1378 		qh->tail = NULL;
1379 		WRITE_ONCE(qh->qlen, 0);
1380 	}
1381 }
1382 
1383 static inline void qdisc_reset_queue(struct Qdisc *sch)
1384 {
1385 	__qdisc_reset_queue(&sch->q);
1386 }
1387 
1388 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1389 					  struct Qdisc **pold)
1390 {
1391 	struct Qdisc *old;
1392 
1393 	sch_tree_lock(sch);
1394 	old = *pold;
1395 	*pold = new;
1396 	if (old != NULL)
1397 		qdisc_purge_queue(old);
1398 	sch_tree_unlock(sch);
1399 
1400 	return old;
1401 }
1402 
1403 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1404 {
1405 	rtnl_kfree_skbs(skb, skb);
1406 	qdisc_qstats_drop(sch);
1407 }
1408 
1409 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1410 				 struct sk_buff **to_free)
1411 {
1412 	__qdisc_drop(skb, to_free);
1413 	qdisc_qstats_cpu_drop(sch);
1414 
1415 	return NET_XMIT_DROP;
1416 }
1417 
1418 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1419 			     struct sk_buff **to_free)
1420 {
1421 	__qdisc_drop(skb, to_free);
1422 	qdisc_qstats_drop(sch);
1423 
1424 	return NET_XMIT_DROP;
1425 }
1426 
1427 static inline int qdisc_drop_reason(struct sk_buff *skb, struct Qdisc *sch,
1428 				    struct sk_buff **to_free,
1429 				    enum qdisc_drop_reason reason)
1430 {
1431 	tcf_set_qdisc_drop_reason(skb, reason);
1432 	return qdisc_drop(skb, sch, to_free);
1433 }
1434 
1435 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1436 				 struct sk_buff **to_free)
1437 {
1438 	__qdisc_drop_all(skb, to_free);
1439 	qdisc_qstats_drop(sch);
1440 
1441 	return NET_XMIT_DROP;
1442 }
1443 
1444 struct psched_ratecfg {
1445 	u64	rate_bytes_ps; /* bytes per second */
1446 	u32	mult;
1447 	u16	overhead;
1448 	u16	mpu;
1449 	u8	linklayer;
1450 	u8	shift;
1451 };
1452 
1453 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1454 				unsigned int len)
1455 {
1456 	len += r->overhead;
1457 
1458 	if (len < r->mpu)
1459 		len = r->mpu;
1460 
1461 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1462 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1463 
1464 	return ((u64)len * r->mult) >> r->shift;
1465 }
1466 
1467 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1468 			       const struct tc_ratespec *conf,
1469 			       u64 rate64);
1470 
1471 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1472 					  const struct psched_ratecfg *r)
1473 {
1474 	memset(res, 0, sizeof(*res));
1475 
1476 	/* legacy struct tc_ratespec has a 32bit @rate field
1477 	 * Qdisc using 64bit rate should add new attributes
1478 	 * in order to maintain compatibility.
1479 	 */
1480 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1481 
1482 	res->overhead = r->overhead;
1483 	res->mpu = r->mpu;
1484 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1485 }
1486 
1487 struct psched_pktrate {
1488 	u64	rate_pkts_ps; /* packets per second */
1489 	u32	mult;
1490 	u8	shift;
1491 };
1492 
1493 static inline u64 psched_pkt2t_ns(const struct psched_pktrate *r,
1494 				  unsigned int pkt_num)
1495 {
1496 	return ((u64)pkt_num * r->mult) >> r->shift;
1497 }
1498 
1499 void psched_ppscfg_precompute(struct psched_pktrate *r, u64 pktrate64);
1500 
1501 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1502  * The fast path only needs to access filter list and to update stats
1503  */
1504 struct mini_Qdisc {
1505 	struct tcf_proto *filter_list;
1506 	struct tcf_block *block;
1507 	struct gnet_stats_basic_sync __percpu *cpu_bstats;
1508 	struct gnet_stats_queue	__percpu *cpu_qstats;
1509 	unsigned long rcu_state;
1510 };
1511 
1512 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1513 						const struct sk_buff *skb)
1514 {
1515 	bstats_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1516 }
1517 
1518 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1519 {
1520 	this_cpu_inc(miniq->cpu_qstats->drops);
1521 }
1522 
1523 struct mini_Qdisc_pair {
1524 	struct mini_Qdisc miniq1;
1525 	struct mini_Qdisc miniq2;
1526 	struct mini_Qdisc __rcu **p_miniq;
1527 };
1528 
1529 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1530 			  struct tcf_proto *tp_head);
1531 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1532 			  struct mini_Qdisc __rcu **p_miniq);
1533 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1534 				struct tcf_block *block);
1535 
1536 static inline bool mini_qdisc_pair_inited(struct mini_Qdisc_pair *miniqp)
1537 {
1538 	return !!miniqp->p_miniq;
1539 }
1540 
1541 void mq_change_real_num_tx(struct Qdisc *sch, unsigned int new_real_tx);
1542 
1543 int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));
1544 
1545 /* Make sure qdisc is no longer in SCHED state. */
1546 static inline void qdisc_synchronize(const struct Qdisc *q)
1547 {
1548 	while (test_bit(__QDISC_STATE_SCHED, &q->state))
1549 		msleep(1);
1550 }
1551 
1552 #endif
1553