xref: /openbmc/linux/include/net/sch_generic.h (revision 5c779702)
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 };
392 
393 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
394 
395 struct tcf_chain {
396 	/* Protects filter_chain. */
397 	struct mutex filter_chain_lock;
398 	struct tcf_proto __rcu *filter_chain;
399 	struct list_head list;
400 	struct tcf_block *block;
401 	u32 index; /* chain index */
402 	unsigned int refcnt;
403 	unsigned int action_refcnt;
404 	bool explicitly_created;
405 	bool flushing;
406 	const struct tcf_proto_ops *tmplt_ops;
407 	void *tmplt_priv;
408 	struct rcu_head rcu;
409 };
410 
411 struct tcf_block {
412 	/* Lock protects tcf_block and lifetime-management data of chains
413 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
414 	 */
415 	struct mutex lock;
416 	struct list_head chain_list;
417 	u32 index; /* block index for shared blocks */
418 	u32 classid; /* which class this block belongs to */
419 	refcount_t refcnt;
420 	struct net *net;
421 	struct Qdisc *q;
422 	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
423 	struct flow_block flow_block;
424 	struct list_head owner_list;
425 	bool keep_dst;
426 	atomic_t offloadcnt; /* Number of oddloaded filters */
427 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
428 	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
429 	struct {
430 		struct tcf_chain *chain;
431 		struct list_head filter_chain_list;
432 	} chain0;
433 	struct rcu_head rcu;
434 	DECLARE_HASHTABLE(proto_destroy_ht, 7);
435 	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
436 };
437 
438 #ifdef CONFIG_PROVE_LOCKING
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 #else
449 static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
450 {
451 	return true;
452 }
453 
454 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
455 {
456 	return true;
457 }
458 #endif /* #ifdef CONFIG_PROVE_LOCKING */
459 
460 #define tcf_chain_dereference(p, chain)					\
461 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
462 
463 #define tcf_proto_dereference(p, tp)					\
464 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
465 
466 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
467 {
468 	struct qdisc_skb_cb *qcb;
469 
470 	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
471 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
472 }
473 
474 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
475 {
476 	return this_cpu_ptr(q->cpu_qstats)->qlen;
477 }
478 
479 static inline int qdisc_qlen(const struct Qdisc *q)
480 {
481 	return q->q.qlen;
482 }
483 
484 static inline int qdisc_qlen_sum(const struct Qdisc *q)
485 {
486 	__u32 qlen = q->qstats.qlen;
487 	int i;
488 
489 	if (qdisc_is_percpu_stats(q)) {
490 		for_each_possible_cpu(i)
491 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
492 	} else {
493 		qlen += q->q.qlen;
494 	}
495 
496 	return qlen;
497 }
498 
499 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
500 {
501 	return (struct qdisc_skb_cb *)skb->cb;
502 }
503 
504 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
505 {
506 	return &qdisc->q.lock;
507 }
508 
509 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
510 {
511 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
512 
513 	return q;
514 }
515 
516 static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
517 {
518 	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
519 }
520 
521 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
522 {
523 	return qdisc->dev_queue->qdisc_sleeping;
524 }
525 
526 /* The qdisc root lock is a mechanism by which to top level
527  * of a qdisc tree can be locked from any qdisc node in the
528  * forest.  This allows changing the configuration of some
529  * aspect of the qdisc tree while blocking out asynchronous
530  * qdisc access in the packet processing paths.
531  *
532  * It is only legal to do this when the root will not change
533  * on us.  Otherwise we'll potentially lock the wrong qdisc
534  * root.  This is enforced by holding the RTNL semaphore, which
535  * all users of this lock accessor must do.
536  */
537 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
538 {
539 	struct Qdisc *root = qdisc_root(qdisc);
540 
541 	ASSERT_RTNL();
542 	return qdisc_lock(root);
543 }
544 
545 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
546 {
547 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
548 
549 	ASSERT_RTNL();
550 	return qdisc_lock(root);
551 }
552 
553 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
554 {
555 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
556 
557 	ASSERT_RTNL();
558 	return &root->running;
559 }
560 
561 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
562 {
563 	return qdisc->dev_queue->dev;
564 }
565 
566 static inline void sch_tree_lock(const struct Qdisc *q)
567 {
568 	spin_lock_bh(qdisc_root_sleeping_lock(q));
569 }
570 
571 static inline void sch_tree_unlock(const struct Qdisc *q)
572 {
573 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
574 }
575 
576 extern struct Qdisc noop_qdisc;
577 extern struct Qdisc_ops noop_qdisc_ops;
578 extern struct Qdisc_ops pfifo_fast_ops;
579 extern struct Qdisc_ops mq_qdisc_ops;
580 extern struct Qdisc_ops noqueue_qdisc_ops;
581 extern const struct Qdisc_ops *default_qdisc_ops;
582 static inline const struct Qdisc_ops *
583 get_default_qdisc_ops(const struct net_device *dev, int ntx)
584 {
585 	return ntx < dev->real_num_tx_queues ?
586 			default_qdisc_ops : &pfifo_fast_ops;
587 }
588 
589 struct Qdisc_class_common {
590 	u32			classid;
591 	struct hlist_node	hnode;
592 };
593 
594 struct Qdisc_class_hash {
595 	struct hlist_head	*hash;
596 	unsigned int		hashsize;
597 	unsigned int		hashmask;
598 	unsigned int		hashelems;
599 };
600 
601 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
602 {
603 	id ^= id >> 8;
604 	id ^= id >> 4;
605 	return id & mask;
606 }
607 
608 static inline struct Qdisc_class_common *
609 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
610 {
611 	struct Qdisc_class_common *cl;
612 	unsigned int h;
613 
614 	if (!id)
615 		return NULL;
616 
617 	h = qdisc_class_hash(id, hash->hashmask);
618 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
619 		if (cl->classid == id)
620 			return cl;
621 	}
622 	return NULL;
623 }
624 
625 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
626 {
627 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
628 
629 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
630 }
631 
632 int qdisc_class_hash_init(struct Qdisc_class_hash *);
633 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
634 			     struct Qdisc_class_common *);
635 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
636 			     struct Qdisc_class_common *);
637 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
638 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
639 
640 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
641 void dev_init_scheduler(struct net_device *dev);
642 void dev_shutdown(struct net_device *dev);
643 void dev_activate(struct net_device *dev);
644 void dev_deactivate(struct net_device *dev);
645 void dev_deactivate_many(struct list_head *head);
646 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
647 			      struct Qdisc *qdisc);
648 void qdisc_reset(struct Qdisc *qdisc);
649 void qdisc_put(struct Qdisc *qdisc);
650 void qdisc_put_unlocked(struct Qdisc *qdisc);
651 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
652 #ifdef CONFIG_NET_SCHED
653 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
654 			      void *type_data);
655 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
656 				struct Qdisc *new, struct Qdisc *old,
657 				enum tc_setup_type type, void *type_data,
658 				struct netlink_ext_ack *extack);
659 #else
660 static inline int
661 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
662 			  void *type_data)
663 {
664 	q->flags &= ~TCQ_F_OFFLOADED;
665 	return 0;
666 }
667 
668 static inline void
669 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
670 			   struct Qdisc *new, struct Qdisc *old,
671 			   enum tc_setup_type type, void *type_data,
672 			   struct netlink_ext_ack *extack)
673 {
674 }
675 #endif
676 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
677 			  const struct Qdisc_ops *ops,
678 			  struct netlink_ext_ack *extack);
679 void qdisc_free(struct Qdisc *qdisc);
680 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
681 				const struct Qdisc_ops *ops, u32 parentid,
682 				struct netlink_ext_ack *extack);
683 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
684 			       const struct qdisc_size_table *stab);
685 int skb_do_redirect(struct sk_buff *);
686 
687 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
688 {
689 #ifdef CONFIG_NET_CLS_ACT
690 	return skb->tc_at_ingress;
691 #else
692 	return false;
693 #endif
694 }
695 
696 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
697 {
698 #ifdef CONFIG_NET_CLS_ACT
699 	if (skb->tc_skip_classify) {
700 		skb->tc_skip_classify = 0;
701 		return true;
702 	}
703 #endif
704 	return false;
705 }
706 
707 /* Reset all TX qdiscs greater than index of a device.  */
708 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
709 {
710 	struct Qdisc *qdisc;
711 
712 	for (; i < dev->num_tx_queues; i++) {
713 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
714 		if (qdisc) {
715 			spin_lock_bh(qdisc_lock(qdisc));
716 			qdisc_reset(qdisc);
717 			spin_unlock_bh(qdisc_lock(qdisc));
718 		}
719 	}
720 }
721 
722 /* Are all TX queues of the device empty?  */
723 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
724 {
725 	unsigned int i;
726 
727 	rcu_read_lock();
728 	for (i = 0; i < dev->num_tx_queues; i++) {
729 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
730 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
731 
732 		if (!qdisc_is_empty(q)) {
733 			rcu_read_unlock();
734 			return false;
735 		}
736 	}
737 	rcu_read_unlock();
738 	return true;
739 }
740 
741 /* Are any of the TX qdiscs changing?  */
742 static inline bool qdisc_tx_changing(const struct net_device *dev)
743 {
744 	unsigned int i;
745 
746 	for (i = 0; i < dev->num_tx_queues; i++) {
747 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
748 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
749 			return true;
750 	}
751 	return false;
752 }
753 
754 /* Is the device using the noop qdisc on all queues?  */
755 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
756 {
757 	unsigned int i;
758 
759 	for (i = 0; i < dev->num_tx_queues; i++) {
760 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
761 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
762 			return false;
763 	}
764 	return true;
765 }
766 
767 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
768 {
769 	return qdisc_skb_cb(skb)->pkt_len;
770 }
771 
772 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
773 enum net_xmit_qdisc_t {
774 	__NET_XMIT_STOLEN = 0x00010000,
775 	__NET_XMIT_BYPASS = 0x00020000,
776 };
777 
778 #ifdef CONFIG_NET_CLS_ACT
779 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
780 #else
781 #define net_xmit_drop_count(e)	(1)
782 #endif
783 
784 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
785 					   const struct Qdisc *sch)
786 {
787 #ifdef CONFIG_NET_SCHED
788 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
789 
790 	if (stab)
791 		__qdisc_calculate_pkt_len(skb, stab);
792 #endif
793 }
794 
795 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
796 				struct sk_buff **to_free)
797 {
798 	qdisc_calculate_pkt_len(skb, sch);
799 	return sch->enqueue(skb, sch, to_free);
800 }
801 
802 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
803 				  __u64 bytes, __u32 packets)
804 {
805 	bstats->bytes += bytes;
806 	bstats->packets += packets;
807 }
808 
809 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
810 				 const struct sk_buff *skb)
811 {
812 	_bstats_update(bstats,
813 		       qdisc_pkt_len(skb),
814 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
815 }
816 
817 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
818 				      __u64 bytes, __u32 packets)
819 {
820 	u64_stats_update_begin(&bstats->syncp);
821 	_bstats_update(&bstats->bstats, bytes, packets);
822 	u64_stats_update_end(&bstats->syncp);
823 }
824 
825 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
826 				     const struct sk_buff *skb)
827 {
828 	u64_stats_update_begin(&bstats->syncp);
829 	bstats_update(&bstats->bstats, skb);
830 	u64_stats_update_end(&bstats->syncp);
831 }
832 
833 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
834 					   const struct sk_buff *skb)
835 {
836 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
837 }
838 
839 static inline void qdisc_bstats_update(struct Qdisc *sch,
840 				       const struct sk_buff *skb)
841 {
842 	bstats_update(&sch->bstats, skb);
843 }
844 
845 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
846 					    const struct sk_buff *skb)
847 {
848 	sch->qstats.backlog -= qdisc_pkt_len(skb);
849 }
850 
851 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
852 						const struct sk_buff *skb)
853 {
854 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
855 }
856 
857 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
858 					    const struct sk_buff *skb)
859 {
860 	sch->qstats.backlog += qdisc_pkt_len(skb);
861 }
862 
863 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
864 						const struct sk_buff *skb)
865 {
866 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
867 }
868 
869 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
870 {
871 	this_cpu_inc(sch->cpu_qstats->qlen);
872 }
873 
874 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
875 {
876 	this_cpu_dec(sch->cpu_qstats->qlen);
877 }
878 
879 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
880 {
881 	this_cpu_inc(sch->cpu_qstats->requeues);
882 }
883 
884 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
885 {
886 	sch->qstats.drops += count;
887 }
888 
889 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
890 {
891 	qstats->drops++;
892 }
893 
894 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
895 {
896 	qstats->overlimits++;
897 }
898 
899 static inline void qdisc_qstats_drop(struct Qdisc *sch)
900 {
901 	qstats_drop_inc(&sch->qstats);
902 }
903 
904 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
905 {
906 	this_cpu_inc(sch->cpu_qstats->drops);
907 }
908 
909 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
910 {
911 	sch->qstats.overlimits++;
912 }
913 
914 static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
915 {
916 	__u32 qlen = qdisc_qlen_sum(sch);
917 
918 	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
919 }
920 
921 static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
922 					     __u32 *backlog)
923 {
924 	struct gnet_stats_queue qstats = { 0 };
925 	__u32 len = qdisc_qlen_sum(sch);
926 
927 	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
928 	*qlen = qstats.qlen;
929 	*backlog = qstats.backlog;
930 }
931 
932 static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
933 {
934 	__u32 qlen, backlog;
935 
936 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
937 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
938 }
939 
940 static inline void qdisc_purge_queue(struct Qdisc *sch)
941 {
942 	__u32 qlen, backlog;
943 
944 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
945 	qdisc_reset(sch);
946 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
947 }
948 
949 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
950 {
951 	qh->head = NULL;
952 	qh->tail = NULL;
953 	qh->qlen = 0;
954 }
955 
956 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
957 					struct qdisc_skb_head *qh)
958 {
959 	struct sk_buff *last = qh->tail;
960 
961 	if (last) {
962 		skb->next = NULL;
963 		last->next = skb;
964 		qh->tail = skb;
965 	} else {
966 		qh->tail = skb;
967 		qh->head = skb;
968 	}
969 	qh->qlen++;
970 }
971 
972 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
973 {
974 	__qdisc_enqueue_tail(skb, &sch->q);
975 	qdisc_qstats_backlog_inc(sch, skb);
976 	return NET_XMIT_SUCCESS;
977 }
978 
979 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
980 					struct qdisc_skb_head *qh)
981 {
982 	skb->next = qh->head;
983 
984 	if (!qh->head)
985 		qh->tail = skb;
986 	qh->head = skb;
987 	qh->qlen++;
988 }
989 
990 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
991 {
992 	struct sk_buff *skb = qh->head;
993 
994 	if (likely(skb != NULL)) {
995 		qh->head = skb->next;
996 		qh->qlen--;
997 		if (qh->head == NULL)
998 			qh->tail = NULL;
999 		skb->next = NULL;
1000 	}
1001 
1002 	return skb;
1003 }
1004 
1005 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
1006 {
1007 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
1008 
1009 	if (likely(skb != NULL)) {
1010 		qdisc_qstats_backlog_dec(sch, skb);
1011 		qdisc_bstats_update(sch, skb);
1012 	}
1013 
1014 	return skb;
1015 }
1016 
1017 /* Instead of calling kfree_skb() while root qdisc lock is held,
1018  * queue the skb for future freeing at end of __dev_xmit_skb()
1019  */
1020 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1021 {
1022 	skb->next = *to_free;
1023 	*to_free = skb;
1024 }
1025 
1026 static inline void __qdisc_drop_all(struct sk_buff *skb,
1027 				    struct sk_buff **to_free)
1028 {
1029 	if (skb->prev)
1030 		skb->prev->next = *to_free;
1031 	else
1032 		skb->next = *to_free;
1033 	*to_free = skb;
1034 }
1035 
1036 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1037 						   struct qdisc_skb_head *qh,
1038 						   struct sk_buff **to_free)
1039 {
1040 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1041 
1042 	if (likely(skb != NULL)) {
1043 		unsigned int len = qdisc_pkt_len(skb);
1044 
1045 		qdisc_qstats_backlog_dec(sch, skb);
1046 		__qdisc_drop(skb, to_free);
1047 		return len;
1048 	}
1049 
1050 	return 0;
1051 }
1052 
1053 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1054 {
1055 	const struct qdisc_skb_head *qh = &sch->q;
1056 
1057 	return qh->head;
1058 }
1059 
1060 /* generic pseudo peek method for non-work-conserving qdisc */
1061 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1062 {
1063 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1064 
1065 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1066 	if (!skb) {
1067 		skb = sch->dequeue(sch);
1068 
1069 		if (skb) {
1070 			__skb_queue_head(&sch->gso_skb, skb);
1071 			/* it's still part of the queue */
1072 			qdisc_qstats_backlog_inc(sch, skb);
1073 			sch->q.qlen++;
1074 		}
1075 	}
1076 
1077 	return skb;
1078 }
1079 
1080 static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1081 						 struct sk_buff *skb)
1082 {
1083 	if (qdisc_is_percpu_stats(sch)) {
1084 		qdisc_qstats_cpu_backlog_dec(sch, skb);
1085 		qdisc_bstats_cpu_update(sch, skb);
1086 		qdisc_qstats_cpu_qlen_dec(sch);
1087 	} else {
1088 		qdisc_qstats_backlog_dec(sch, skb);
1089 		qdisc_bstats_update(sch, skb);
1090 		sch->q.qlen--;
1091 	}
1092 }
1093 
1094 static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1095 						 unsigned int pkt_len)
1096 {
1097 	if (qdisc_is_percpu_stats(sch)) {
1098 		qdisc_qstats_cpu_qlen_inc(sch);
1099 		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1100 	} else {
1101 		sch->qstats.backlog += pkt_len;
1102 		sch->q.qlen++;
1103 	}
1104 }
1105 
1106 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1107 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1108 {
1109 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1110 
1111 	if (skb) {
1112 		skb = __skb_dequeue(&sch->gso_skb);
1113 		if (qdisc_is_percpu_stats(sch)) {
1114 			qdisc_qstats_cpu_backlog_dec(sch, skb);
1115 			qdisc_qstats_cpu_qlen_dec(sch);
1116 		} else {
1117 			qdisc_qstats_backlog_dec(sch, skb);
1118 			sch->q.qlen--;
1119 		}
1120 	} else {
1121 		skb = sch->dequeue(sch);
1122 	}
1123 
1124 	return skb;
1125 }
1126 
1127 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1128 {
1129 	/*
1130 	 * We do not know the backlog in bytes of this list, it
1131 	 * is up to the caller to correct it
1132 	 */
1133 	ASSERT_RTNL();
1134 	if (qh->qlen) {
1135 		rtnl_kfree_skbs(qh->head, qh->tail);
1136 
1137 		qh->head = NULL;
1138 		qh->tail = NULL;
1139 		qh->qlen = 0;
1140 	}
1141 }
1142 
1143 static inline void qdisc_reset_queue(struct Qdisc *sch)
1144 {
1145 	__qdisc_reset_queue(&sch->q);
1146 	sch->qstats.backlog = 0;
1147 }
1148 
1149 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1150 					  struct Qdisc **pold)
1151 {
1152 	struct Qdisc *old;
1153 
1154 	sch_tree_lock(sch);
1155 	old = *pold;
1156 	*pold = new;
1157 	if (old != NULL)
1158 		qdisc_tree_flush_backlog(old);
1159 	sch_tree_unlock(sch);
1160 
1161 	return old;
1162 }
1163 
1164 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1165 {
1166 	rtnl_kfree_skbs(skb, skb);
1167 	qdisc_qstats_drop(sch);
1168 }
1169 
1170 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1171 				 struct sk_buff **to_free)
1172 {
1173 	__qdisc_drop(skb, to_free);
1174 	qdisc_qstats_cpu_drop(sch);
1175 
1176 	return NET_XMIT_DROP;
1177 }
1178 
1179 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1180 			     struct sk_buff **to_free)
1181 {
1182 	__qdisc_drop(skb, to_free);
1183 	qdisc_qstats_drop(sch);
1184 
1185 	return NET_XMIT_DROP;
1186 }
1187 
1188 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1189 				 struct sk_buff **to_free)
1190 {
1191 	__qdisc_drop_all(skb, to_free);
1192 	qdisc_qstats_drop(sch);
1193 
1194 	return NET_XMIT_DROP;
1195 }
1196 
1197 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1198    long it will take to send a packet given its size.
1199  */
1200 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1201 {
1202 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1203 	if (slot < 0)
1204 		slot = 0;
1205 	slot >>= rtab->rate.cell_log;
1206 	if (slot > 255)
1207 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1208 	return rtab->data[slot];
1209 }
1210 
1211 struct psched_ratecfg {
1212 	u64	rate_bytes_ps; /* bytes per second */
1213 	u32	mult;
1214 	u16	overhead;
1215 	u8	linklayer;
1216 	u8	shift;
1217 };
1218 
1219 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1220 				unsigned int len)
1221 {
1222 	len += r->overhead;
1223 
1224 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1225 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1226 
1227 	return ((u64)len * r->mult) >> r->shift;
1228 }
1229 
1230 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1231 			       const struct tc_ratespec *conf,
1232 			       u64 rate64);
1233 
1234 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1235 					  const struct psched_ratecfg *r)
1236 {
1237 	memset(res, 0, sizeof(*res));
1238 
1239 	/* legacy struct tc_ratespec has a 32bit @rate field
1240 	 * Qdisc using 64bit rate should add new attributes
1241 	 * in order to maintain compatibility.
1242 	 */
1243 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1244 
1245 	res->overhead = r->overhead;
1246 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1247 }
1248 
1249 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1250  * The fast path only needs to access filter list and to update stats
1251  */
1252 struct mini_Qdisc {
1253 	struct tcf_proto *filter_list;
1254 	struct tcf_block *block;
1255 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1256 	struct gnet_stats_queue	__percpu *cpu_qstats;
1257 	struct rcu_head rcu;
1258 };
1259 
1260 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1261 						const struct sk_buff *skb)
1262 {
1263 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1264 }
1265 
1266 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1267 {
1268 	this_cpu_inc(miniq->cpu_qstats->drops);
1269 }
1270 
1271 struct mini_Qdisc_pair {
1272 	struct mini_Qdisc miniq1;
1273 	struct mini_Qdisc miniq2;
1274 	struct mini_Qdisc __rcu **p_miniq;
1275 };
1276 
1277 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1278 			  struct tcf_proto *tp_head);
1279 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1280 			  struct mini_Qdisc __rcu **p_miniq);
1281 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1282 				struct tcf_block *block);
1283 
1284 static inline int skb_tc_reinsert(struct sk_buff *skb, struct tcf_result *res)
1285 {
1286 	return res->ingress ? netif_receive_skb(skb) : dev_queue_xmit(skb);
1287 }
1288 
1289 #endif
1290