xref: /openbmc/linux/include/net/sch_generic.h (revision b9dd2add)
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 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
439 {
440 	return lockdep_is_held(&chain->filter_chain_lock);
441 }
442 
443 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
444 {
445 	return lockdep_is_held(&tp->lock);
446 }
447 
448 #define tcf_chain_dereference(p, chain)					\
449 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
450 
451 #define tcf_proto_dereference(p, tp)					\
452 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
453 
454 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
455 {
456 	struct qdisc_skb_cb *qcb;
457 
458 	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
459 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
460 }
461 
462 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
463 {
464 	return this_cpu_ptr(q->cpu_qstats)->qlen;
465 }
466 
467 static inline int qdisc_qlen(const struct Qdisc *q)
468 {
469 	return q->q.qlen;
470 }
471 
472 static inline int qdisc_qlen_sum(const struct Qdisc *q)
473 {
474 	__u32 qlen = q->qstats.qlen;
475 	int i;
476 
477 	if (qdisc_is_percpu_stats(q)) {
478 		for_each_possible_cpu(i)
479 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
480 	} else {
481 		qlen += q->q.qlen;
482 	}
483 
484 	return qlen;
485 }
486 
487 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
488 {
489 	return (struct qdisc_skb_cb *)skb->cb;
490 }
491 
492 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
493 {
494 	return &qdisc->q.lock;
495 }
496 
497 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
498 {
499 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
500 
501 	return q;
502 }
503 
504 static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
505 {
506 	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
507 }
508 
509 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
510 {
511 	return qdisc->dev_queue->qdisc_sleeping;
512 }
513 
514 /* The qdisc root lock is a mechanism by which to top level
515  * of a qdisc tree can be locked from any qdisc node in the
516  * forest.  This allows changing the configuration of some
517  * aspect of the qdisc tree while blocking out asynchronous
518  * qdisc access in the packet processing paths.
519  *
520  * It is only legal to do this when the root will not change
521  * on us.  Otherwise we'll potentially lock the wrong qdisc
522  * root.  This is enforced by holding the RTNL semaphore, which
523  * all users of this lock accessor must do.
524  */
525 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
526 {
527 	struct Qdisc *root = qdisc_root(qdisc);
528 
529 	ASSERT_RTNL();
530 	return qdisc_lock(root);
531 }
532 
533 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
534 {
535 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
536 
537 	ASSERT_RTNL();
538 	return qdisc_lock(root);
539 }
540 
541 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
542 {
543 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
544 
545 	ASSERT_RTNL();
546 	return &root->running;
547 }
548 
549 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
550 {
551 	return qdisc->dev_queue->dev;
552 }
553 
554 static inline void sch_tree_lock(const struct Qdisc *q)
555 {
556 	spin_lock_bh(qdisc_root_sleeping_lock(q));
557 }
558 
559 static inline void sch_tree_unlock(const struct Qdisc *q)
560 {
561 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
562 }
563 
564 extern struct Qdisc noop_qdisc;
565 extern struct Qdisc_ops noop_qdisc_ops;
566 extern struct Qdisc_ops pfifo_fast_ops;
567 extern struct Qdisc_ops mq_qdisc_ops;
568 extern struct Qdisc_ops noqueue_qdisc_ops;
569 extern const struct Qdisc_ops *default_qdisc_ops;
570 static inline const struct Qdisc_ops *
571 get_default_qdisc_ops(const struct net_device *dev, int ntx)
572 {
573 	return ntx < dev->real_num_tx_queues ?
574 			default_qdisc_ops : &pfifo_fast_ops;
575 }
576 
577 struct Qdisc_class_common {
578 	u32			classid;
579 	struct hlist_node	hnode;
580 };
581 
582 struct Qdisc_class_hash {
583 	struct hlist_head	*hash;
584 	unsigned int		hashsize;
585 	unsigned int		hashmask;
586 	unsigned int		hashelems;
587 };
588 
589 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
590 {
591 	id ^= id >> 8;
592 	id ^= id >> 4;
593 	return id & mask;
594 }
595 
596 static inline struct Qdisc_class_common *
597 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
598 {
599 	struct Qdisc_class_common *cl;
600 	unsigned int h;
601 
602 	if (!id)
603 		return NULL;
604 
605 	h = qdisc_class_hash(id, hash->hashmask);
606 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
607 		if (cl->classid == id)
608 			return cl;
609 	}
610 	return NULL;
611 }
612 
613 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
614 {
615 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
616 
617 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
618 }
619 
620 int qdisc_class_hash_init(struct Qdisc_class_hash *);
621 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
622 			     struct Qdisc_class_common *);
623 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
624 			     struct Qdisc_class_common *);
625 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
626 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
627 
628 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
629 void dev_init_scheduler(struct net_device *dev);
630 void dev_shutdown(struct net_device *dev);
631 void dev_activate(struct net_device *dev);
632 void dev_deactivate(struct net_device *dev);
633 void dev_deactivate_many(struct list_head *head);
634 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
635 			      struct Qdisc *qdisc);
636 void qdisc_reset(struct Qdisc *qdisc);
637 void qdisc_put(struct Qdisc *qdisc);
638 void qdisc_put_unlocked(struct Qdisc *qdisc);
639 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
640 #ifdef CONFIG_NET_SCHED
641 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
642 			      void *type_data);
643 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
644 				struct Qdisc *new, struct Qdisc *old,
645 				enum tc_setup_type type, void *type_data,
646 				struct netlink_ext_ack *extack);
647 #else
648 static inline int
649 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
650 			  void *type_data)
651 {
652 	q->flags &= ~TCQ_F_OFFLOADED;
653 	return 0;
654 }
655 
656 static inline void
657 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
658 			   struct Qdisc *new, struct Qdisc *old,
659 			   enum tc_setup_type type, void *type_data,
660 			   struct netlink_ext_ack *extack)
661 {
662 }
663 #endif
664 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
665 			  const struct Qdisc_ops *ops,
666 			  struct netlink_ext_ack *extack);
667 void qdisc_free(struct Qdisc *qdisc);
668 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
669 				const struct Qdisc_ops *ops, u32 parentid,
670 				struct netlink_ext_ack *extack);
671 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
672 			       const struct qdisc_size_table *stab);
673 int skb_do_redirect(struct sk_buff *);
674 
675 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
676 {
677 #ifdef CONFIG_NET_CLS_ACT
678 	return skb->tc_at_ingress;
679 #else
680 	return false;
681 #endif
682 }
683 
684 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
685 {
686 #ifdef CONFIG_NET_CLS_ACT
687 	if (skb->tc_skip_classify) {
688 		skb->tc_skip_classify = 0;
689 		return true;
690 	}
691 #endif
692 	return false;
693 }
694 
695 /* Reset all TX qdiscs greater than index of a device.  */
696 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
697 {
698 	struct Qdisc *qdisc;
699 
700 	for (; i < dev->num_tx_queues; i++) {
701 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
702 		if (qdisc) {
703 			spin_lock_bh(qdisc_lock(qdisc));
704 			qdisc_reset(qdisc);
705 			spin_unlock_bh(qdisc_lock(qdisc));
706 		}
707 	}
708 }
709 
710 /* Are all TX queues of the device empty?  */
711 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
712 {
713 	unsigned int i;
714 
715 	rcu_read_lock();
716 	for (i = 0; i < dev->num_tx_queues; i++) {
717 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
718 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
719 
720 		if (!qdisc_is_empty(q)) {
721 			rcu_read_unlock();
722 			return false;
723 		}
724 	}
725 	rcu_read_unlock();
726 	return true;
727 }
728 
729 /* Are any of the TX qdiscs changing?  */
730 static inline bool qdisc_tx_changing(const struct net_device *dev)
731 {
732 	unsigned int i;
733 
734 	for (i = 0; i < dev->num_tx_queues; i++) {
735 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
736 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
737 			return true;
738 	}
739 	return false;
740 }
741 
742 /* Is the device using the noop qdisc on all queues?  */
743 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
744 {
745 	unsigned int i;
746 
747 	for (i = 0; i < dev->num_tx_queues; i++) {
748 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
749 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
750 			return false;
751 	}
752 	return true;
753 }
754 
755 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
756 {
757 	return qdisc_skb_cb(skb)->pkt_len;
758 }
759 
760 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
761 enum net_xmit_qdisc_t {
762 	__NET_XMIT_STOLEN = 0x00010000,
763 	__NET_XMIT_BYPASS = 0x00020000,
764 };
765 
766 #ifdef CONFIG_NET_CLS_ACT
767 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
768 #else
769 #define net_xmit_drop_count(e)	(1)
770 #endif
771 
772 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
773 					   const struct Qdisc *sch)
774 {
775 #ifdef CONFIG_NET_SCHED
776 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
777 
778 	if (stab)
779 		__qdisc_calculate_pkt_len(skb, stab);
780 #endif
781 }
782 
783 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
784 				struct sk_buff **to_free)
785 {
786 	qdisc_calculate_pkt_len(skb, sch);
787 	return sch->enqueue(skb, sch, to_free);
788 }
789 
790 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
791 				  __u64 bytes, __u32 packets)
792 {
793 	bstats->bytes += bytes;
794 	bstats->packets += packets;
795 }
796 
797 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
798 				 const struct sk_buff *skb)
799 {
800 	_bstats_update(bstats,
801 		       qdisc_pkt_len(skb),
802 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
803 }
804 
805 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
806 				      __u64 bytes, __u32 packets)
807 {
808 	u64_stats_update_begin(&bstats->syncp);
809 	_bstats_update(&bstats->bstats, bytes, packets);
810 	u64_stats_update_end(&bstats->syncp);
811 }
812 
813 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
814 				     const struct sk_buff *skb)
815 {
816 	u64_stats_update_begin(&bstats->syncp);
817 	bstats_update(&bstats->bstats, skb);
818 	u64_stats_update_end(&bstats->syncp);
819 }
820 
821 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
822 					   const struct sk_buff *skb)
823 {
824 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
825 }
826 
827 static inline void qdisc_bstats_update(struct Qdisc *sch,
828 				       const struct sk_buff *skb)
829 {
830 	bstats_update(&sch->bstats, skb);
831 }
832 
833 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
834 					    const struct sk_buff *skb)
835 {
836 	sch->qstats.backlog -= qdisc_pkt_len(skb);
837 }
838 
839 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
840 						const struct sk_buff *skb)
841 {
842 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
843 }
844 
845 static inline void qdisc_qstats_backlog_inc(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_inc(struct Qdisc *sch,
852 						const struct sk_buff *skb)
853 {
854 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
855 }
856 
857 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
858 {
859 	this_cpu_inc(sch->cpu_qstats->qlen);
860 }
861 
862 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
863 {
864 	this_cpu_dec(sch->cpu_qstats->qlen);
865 }
866 
867 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
868 {
869 	this_cpu_inc(sch->cpu_qstats->requeues);
870 }
871 
872 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
873 {
874 	sch->qstats.drops += count;
875 }
876 
877 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
878 {
879 	qstats->drops++;
880 }
881 
882 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
883 {
884 	qstats->overlimits++;
885 }
886 
887 static inline void qdisc_qstats_drop(struct Qdisc *sch)
888 {
889 	qstats_drop_inc(&sch->qstats);
890 }
891 
892 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
893 {
894 	this_cpu_inc(sch->cpu_qstats->drops);
895 }
896 
897 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
898 {
899 	sch->qstats.overlimits++;
900 }
901 
902 static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
903 {
904 	__u32 qlen = qdisc_qlen_sum(sch);
905 
906 	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
907 }
908 
909 static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
910 					     __u32 *backlog)
911 {
912 	struct gnet_stats_queue qstats = { 0 };
913 	__u32 len = qdisc_qlen_sum(sch);
914 
915 	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
916 	*qlen = qstats.qlen;
917 	*backlog = qstats.backlog;
918 }
919 
920 static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
921 {
922 	__u32 qlen, backlog;
923 
924 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
925 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
926 }
927 
928 static inline void qdisc_purge_queue(struct Qdisc *sch)
929 {
930 	__u32 qlen, backlog;
931 
932 	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
933 	qdisc_reset(sch);
934 	qdisc_tree_reduce_backlog(sch, qlen, backlog);
935 }
936 
937 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
938 {
939 	qh->head = NULL;
940 	qh->tail = NULL;
941 	qh->qlen = 0;
942 }
943 
944 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
945 					struct qdisc_skb_head *qh)
946 {
947 	struct sk_buff *last = qh->tail;
948 
949 	if (last) {
950 		skb->next = NULL;
951 		last->next = skb;
952 		qh->tail = skb;
953 	} else {
954 		qh->tail = skb;
955 		qh->head = skb;
956 	}
957 	qh->qlen++;
958 }
959 
960 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
961 {
962 	__qdisc_enqueue_tail(skb, &sch->q);
963 	qdisc_qstats_backlog_inc(sch, skb);
964 	return NET_XMIT_SUCCESS;
965 }
966 
967 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
968 					struct qdisc_skb_head *qh)
969 {
970 	skb->next = qh->head;
971 
972 	if (!qh->head)
973 		qh->tail = skb;
974 	qh->head = skb;
975 	qh->qlen++;
976 }
977 
978 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
979 {
980 	struct sk_buff *skb = qh->head;
981 
982 	if (likely(skb != NULL)) {
983 		qh->head = skb->next;
984 		qh->qlen--;
985 		if (qh->head == NULL)
986 			qh->tail = NULL;
987 		skb->next = NULL;
988 	}
989 
990 	return skb;
991 }
992 
993 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
994 {
995 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
996 
997 	if (likely(skb != NULL)) {
998 		qdisc_qstats_backlog_dec(sch, skb);
999 		qdisc_bstats_update(sch, skb);
1000 	}
1001 
1002 	return skb;
1003 }
1004 
1005 /* Instead of calling kfree_skb() while root qdisc lock is held,
1006  * queue the skb for future freeing at end of __dev_xmit_skb()
1007  */
1008 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1009 {
1010 	skb->next = *to_free;
1011 	*to_free = skb;
1012 }
1013 
1014 static inline void __qdisc_drop_all(struct sk_buff *skb,
1015 				    struct sk_buff **to_free)
1016 {
1017 	if (skb->prev)
1018 		skb->prev->next = *to_free;
1019 	else
1020 		skb->next = *to_free;
1021 	*to_free = skb;
1022 }
1023 
1024 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1025 						   struct qdisc_skb_head *qh,
1026 						   struct sk_buff **to_free)
1027 {
1028 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1029 
1030 	if (likely(skb != NULL)) {
1031 		unsigned int len = qdisc_pkt_len(skb);
1032 
1033 		qdisc_qstats_backlog_dec(sch, skb);
1034 		__qdisc_drop(skb, to_free);
1035 		return len;
1036 	}
1037 
1038 	return 0;
1039 }
1040 
1041 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1042 {
1043 	const struct qdisc_skb_head *qh = &sch->q;
1044 
1045 	return qh->head;
1046 }
1047 
1048 /* generic pseudo peek method for non-work-conserving qdisc */
1049 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1050 {
1051 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1052 
1053 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1054 	if (!skb) {
1055 		skb = sch->dequeue(sch);
1056 
1057 		if (skb) {
1058 			__skb_queue_head(&sch->gso_skb, skb);
1059 			/* it's still part of the queue */
1060 			qdisc_qstats_backlog_inc(sch, skb);
1061 			sch->q.qlen++;
1062 		}
1063 	}
1064 
1065 	return skb;
1066 }
1067 
1068 static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1069 						 struct sk_buff *skb)
1070 {
1071 	if (qdisc_is_percpu_stats(sch)) {
1072 		qdisc_qstats_cpu_backlog_dec(sch, skb);
1073 		qdisc_bstats_cpu_update(sch, skb);
1074 		qdisc_qstats_cpu_qlen_dec(sch);
1075 	} else {
1076 		qdisc_qstats_backlog_dec(sch, skb);
1077 		qdisc_bstats_update(sch, skb);
1078 		sch->q.qlen--;
1079 	}
1080 }
1081 
1082 static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1083 						 unsigned int pkt_len)
1084 {
1085 	if (qdisc_is_percpu_stats(sch)) {
1086 		qdisc_qstats_cpu_qlen_inc(sch);
1087 		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1088 	} else {
1089 		sch->qstats.backlog += pkt_len;
1090 		sch->q.qlen++;
1091 	}
1092 }
1093 
1094 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1095 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1096 {
1097 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1098 
1099 	if (skb) {
1100 		skb = __skb_dequeue(&sch->gso_skb);
1101 		if (qdisc_is_percpu_stats(sch)) {
1102 			qdisc_qstats_cpu_backlog_dec(sch, skb);
1103 			qdisc_qstats_cpu_qlen_dec(sch);
1104 		} else {
1105 			qdisc_qstats_backlog_dec(sch, skb);
1106 			sch->q.qlen--;
1107 		}
1108 	} else {
1109 		skb = sch->dequeue(sch);
1110 	}
1111 
1112 	return skb;
1113 }
1114 
1115 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1116 {
1117 	/*
1118 	 * We do not know the backlog in bytes of this list, it
1119 	 * is up to the caller to correct it
1120 	 */
1121 	ASSERT_RTNL();
1122 	if (qh->qlen) {
1123 		rtnl_kfree_skbs(qh->head, qh->tail);
1124 
1125 		qh->head = NULL;
1126 		qh->tail = NULL;
1127 		qh->qlen = 0;
1128 	}
1129 }
1130 
1131 static inline void qdisc_reset_queue(struct Qdisc *sch)
1132 {
1133 	__qdisc_reset_queue(&sch->q);
1134 	sch->qstats.backlog = 0;
1135 }
1136 
1137 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1138 					  struct Qdisc **pold)
1139 {
1140 	struct Qdisc *old;
1141 
1142 	sch_tree_lock(sch);
1143 	old = *pold;
1144 	*pold = new;
1145 	if (old != NULL)
1146 		qdisc_tree_flush_backlog(old);
1147 	sch_tree_unlock(sch);
1148 
1149 	return old;
1150 }
1151 
1152 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1153 {
1154 	rtnl_kfree_skbs(skb, skb);
1155 	qdisc_qstats_drop(sch);
1156 }
1157 
1158 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1159 				 struct sk_buff **to_free)
1160 {
1161 	__qdisc_drop(skb, to_free);
1162 	qdisc_qstats_cpu_drop(sch);
1163 
1164 	return NET_XMIT_DROP;
1165 }
1166 
1167 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1168 			     struct sk_buff **to_free)
1169 {
1170 	__qdisc_drop(skb, to_free);
1171 	qdisc_qstats_drop(sch);
1172 
1173 	return NET_XMIT_DROP;
1174 }
1175 
1176 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1177 				 struct sk_buff **to_free)
1178 {
1179 	__qdisc_drop_all(skb, to_free);
1180 	qdisc_qstats_drop(sch);
1181 
1182 	return NET_XMIT_DROP;
1183 }
1184 
1185 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1186    long it will take to send a packet given its size.
1187  */
1188 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1189 {
1190 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1191 	if (slot < 0)
1192 		slot = 0;
1193 	slot >>= rtab->rate.cell_log;
1194 	if (slot > 255)
1195 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1196 	return rtab->data[slot];
1197 }
1198 
1199 struct psched_ratecfg {
1200 	u64	rate_bytes_ps; /* bytes per second */
1201 	u32	mult;
1202 	u16	overhead;
1203 	u8	linklayer;
1204 	u8	shift;
1205 };
1206 
1207 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1208 				unsigned int len)
1209 {
1210 	len += r->overhead;
1211 
1212 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1213 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1214 
1215 	return ((u64)len * r->mult) >> r->shift;
1216 }
1217 
1218 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1219 			       const struct tc_ratespec *conf,
1220 			       u64 rate64);
1221 
1222 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1223 					  const struct psched_ratecfg *r)
1224 {
1225 	memset(res, 0, sizeof(*res));
1226 
1227 	/* legacy struct tc_ratespec has a 32bit @rate field
1228 	 * Qdisc using 64bit rate should add new attributes
1229 	 * in order to maintain compatibility.
1230 	 */
1231 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1232 
1233 	res->overhead = r->overhead;
1234 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1235 }
1236 
1237 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1238  * The fast path only needs to access filter list and to update stats
1239  */
1240 struct mini_Qdisc {
1241 	struct tcf_proto *filter_list;
1242 	struct tcf_block *block;
1243 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1244 	struct gnet_stats_queue	__percpu *cpu_qstats;
1245 	struct rcu_head rcu;
1246 };
1247 
1248 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1249 						const struct sk_buff *skb)
1250 {
1251 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1252 }
1253 
1254 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1255 {
1256 	this_cpu_inc(miniq->cpu_qstats->drops);
1257 }
1258 
1259 struct mini_Qdisc_pair {
1260 	struct mini_Qdisc miniq1;
1261 	struct mini_Qdisc miniq2;
1262 	struct mini_Qdisc __rcu **p_miniq;
1263 };
1264 
1265 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1266 			  struct tcf_proto *tp_head);
1267 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1268 			  struct mini_Qdisc __rcu **p_miniq);
1269 void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1270 				struct tcf_block *block);
1271 
1272 int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb));
1273 
1274 #endif
1275