xref: /openbmc/linux/include/net/sch_generic.h (revision 8bd1369b)
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 <net/gen_stats.h>
16 #include <net/rtnetlink.h>
17 
18 struct Qdisc_ops;
19 struct qdisc_walker;
20 struct tcf_walker;
21 struct module;
22 
23 struct qdisc_rate_table {
24 	struct tc_ratespec rate;
25 	u32		data[256];
26 	struct qdisc_rate_table *next;
27 	int		refcnt;
28 };
29 
30 enum qdisc_state_t {
31 	__QDISC_STATE_SCHED,
32 	__QDISC_STATE_DEACTIVATED,
33 };
34 
35 struct qdisc_size_table {
36 	struct rcu_head		rcu;
37 	struct list_head	list;
38 	struct tc_sizespec	szopts;
39 	int			refcnt;
40 	u16			data[];
41 };
42 
43 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
44 struct qdisc_skb_head {
45 	struct sk_buff	*head;
46 	struct sk_buff	*tail;
47 	__u32		qlen;
48 	spinlock_t	lock;
49 };
50 
51 struct Qdisc {
52 	int 			(*enqueue)(struct sk_buff *skb,
53 					   struct Qdisc *sch,
54 					   struct sk_buff **to_free);
55 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
56 	unsigned int		flags;
57 #define TCQ_F_BUILTIN		1
58 #define TCQ_F_INGRESS		2
59 #define TCQ_F_CAN_BYPASS	4
60 #define TCQ_F_MQROOT		8
61 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
62 				      * q->dev_queue : It can test
63 				      * netif_xmit_frozen_or_stopped() before
64 				      * dequeueing next packet.
65 				      * Its true for MQ/MQPRIO slaves, or non
66 				      * multiqueue device.
67 				      */
68 #define TCQ_F_WARN_NONWC	(1 << 16)
69 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
70 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
71 				      * qdisc_tree_decrease_qlen() should stop.
72 				      */
73 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
74 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
75 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
76 	u32			limit;
77 	const struct Qdisc_ops	*ops;
78 	struct qdisc_size_table	__rcu *stab;
79 	struct hlist_node       hash;
80 	u32			handle;
81 	u32			parent;
82 
83 	struct netdev_queue	*dev_queue;
84 
85 	struct net_rate_estimator __rcu *rate_est;
86 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
87 	struct gnet_stats_queue	__percpu *cpu_qstats;
88 	int			padded;
89 	refcount_t		refcnt;
90 
91 	/*
92 	 * For performance sake on SMP, we put highly modified fields at the end
93 	 */
94 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
95 	struct qdisc_skb_head	q;
96 	struct gnet_stats_basic_packed bstats;
97 	seqcount_t		running;
98 	struct gnet_stats_queue	qstats;
99 	unsigned long		state;
100 	struct Qdisc            *next_sched;
101 	struct sk_buff_head	skb_bad_txq;
102 
103 	spinlock_t		busylock ____cacheline_aligned_in_smp;
104 	spinlock_t		seqlock;
105 };
106 
107 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
108 {
109 	if (qdisc->flags & TCQ_F_BUILTIN)
110 		return;
111 	refcount_inc(&qdisc->refcnt);
112 }
113 
114 static inline bool qdisc_is_running(struct Qdisc *qdisc)
115 {
116 	if (qdisc->flags & TCQ_F_NOLOCK)
117 		return spin_is_locked(&qdisc->seqlock);
118 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
119 }
120 
121 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
122 {
123 	if (qdisc->flags & TCQ_F_NOLOCK) {
124 		if (!spin_trylock(&qdisc->seqlock))
125 			return false;
126 	} else if (qdisc_is_running(qdisc)) {
127 		return false;
128 	}
129 	/* Variant of write_seqcount_begin() telling lockdep a trylock
130 	 * was attempted.
131 	 */
132 	raw_write_seqcount_begin(&qdisc->running);
133 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
134 	return true;
135 }
136 
137 static inline void qdisc_run_end(struct Qdisc *qdisc)
138 {
139 	write_seqcount_end(&qdisc->running);
140 	if (qdisc->flags & TCQ_F_NOLOCK)
141 		spin_unlock(&qdisc->seqlock);
142 }
143 
144 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
145 {
146 	return qdisc->flags & TCQ_F_ONETXQUEUE;
147 }
148 
149 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
150 {
151 #ifdef CONFIG_BQL
152 	/* Non-BQL migrated drivers will return 0, too. */
153 	return dql_avail(&txq->dql);
154 #else
155 	return 0;
156 #endif
157 }
158 
159 struct Qdisc_class_ops {
160 	/* Child qdisc manipulation */
161 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
162 	int			(*graft)(struct Qdisc *, unsigned long cl,
163 					struct Qdisc *, struct Qdisc **,
164 					struct netlink_ext_ack *extack);
165 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
166 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
167 
168 	/* Class manipulation routines */
169 	unsigned long		(*find)(struct Qdisc *, u32 classid);
170 	int			(*change)(struct Qdisc *, u32, u32,
171 					struct nlattr **, unsigned long *,
172 					struct netlink_ext_ack *);
173 	int			(*delete)(struct Qdisc *, unsigned long);
174 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
175 
176 	/* Filter manipulation */
177 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
178 					     unsigned long arg,
179 					     struct netlink_ext_ack *extack);
180 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
181 					u32 classid);
182 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
183 
184 	/* rtnetlink specific */
185 	int			(*dump)(struct Qdisc *, unsigned long,
186 					struct sk_buff *skb, struct tcmsg*);
187 	int			(*dump_stats)(struct Qdisc *, unsigned long,
188 					struct gnet_dump *);
189 };
190 
191 struct Qdisc_ops {
192 	struct Qdisc_ops	*next;
193 	const struct Qdisc_class_ops	*cl_ops;
194 	char			id[IFNAMSIZ];
195 	int			priv_size;
196 	unsigned int		static_flags;
197 
198 	int 			(*enqueue)(struct sk_buff *skb,
199 					   struct Qdisc *sch,
200 					   struct sk_buff **to_free);
201 	struct sk_buff *	(*dequeue)(struct Qdisc *);
202 	struct sk_buff *	(*peek)(struct Qdisc *);
203 
204 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
205 					struct netlink_ext_ack *extack);
206 	void			(*reset)(struct Qdisc *);
207 	void			(*destroy)(struct Qdisc *);
208 	int			(*change)(struct Qdisc *sch,
209 					  struct nlattr *arg,
210 					  struct netlink_ext_ack *extack);
211 	void			(*attach)(struct Qdisc *sch);
212 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
213 
214 	int			(*dump)(struct Qdisc *, struct sk_buff *);
215 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
216 
217 	void			(*ingress_block_set)(struct Qdisc *sch,
218 						     u32 block_index);
219 	void			(*egress_block_set)(struct Qdisc *sch,
220 						    u32 block_index);
221 	u32			(*ingress_block_get)(struct Qdisc *sch);
222 	u32			(*egress_block_get)(struct Qdisc *sch);
223 
224 	struct module		*owner;
225 };
226 
227 
228 struct tcf_result {
229 	union {
230 		struct {
231 			unsigned long	class;
232 			u32		classid;
233 		};
234 		const struct tcf_proto *goto_tp;
235 	};
236 };
237 
238 struct tcf_proto_ops {
239 	struct list_head	head;
240 	char			kind[IFNAMSIZ];
241 
242 	int			(*classify)(struct sk_buff *,
243 					    const struct tcf_proto *,
244 					    struct tcf_result *);
245 	int			(*init)(struct tcf_proto*);
246 	void			(*destroy)(struct tcf_proto *tp,
247 					   struct netlink_ext_ack *extack);
248 
249 	void*			(*get)(struct tcf_proto*, u32 handle);
250 	int			(*change)(struct net *net, struct sk_buff *,
251 					struct tcf_proto*, unsigned long,
252 					u32 handle, struct nlattr **,
253 					void **, bool,
254 					struct netlink_ext_ack *);
255 	int			(*delete)(struct tcf_proto *tp, void *arg,
256 					  bool *last,
257 					  struct netlink_ext_ack *);
258 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
259 	void			(*bind_class)(void *, u32, unsigned long);
260 
261 	/* rtnetlink specific */
262 	int			(*dump)(struct net*, struct tcf_proto*, void *,
263 					struct sk_buff *skb, struct tcmsg*);
264 
265 	struct module		*owner;
266 };
267 
268 struct tcf_proto {
269 	/* Fast access part */
270 	struct tcf_proto __rcu	*next;
271 	void __rcu		*root;
272 	int			(*classify)(struct sk_buff *,
273 					    const struct tcf_proto *,
274 					    struct tcf_result *);
275 	__be16			protocol;
276 
277 	/* All the rest */
278 	u32			prio;
279 	void			*data;
280 	const struct tcf_proto_ops	*ops;
281 	struct tcf_chain	*chain;
282 	struct rcu_head		rcu;
283 };
284 
285 struct qdisc_skb_cb {
286 	unsigned int		pkt_len;
287 	u16			slave_dev_queue_mapping;
288 	u16			tc_classid;
289 #define QDISC_CB_PRIV_LEN 20
290 	unsigned char		data[QDISC_CB_PRIV_LEN];
291 };
292 
293 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
294 
295 struct tcf_chain {
296 	struct tcf_proto __rcu *filter_chain;
297 	struct list_head filter_chain_list;
298 	struct list_head list;
299 	struct tcf_block *block;
300 	u32 index; /* chain index */
301 	unsigned int refcnt;
302 };
303 
304 struct tcf_block {
305 	struct list_head chain_list;
306 	u32 index; /* block index for shared blocks */
307 	unsigned int refcnt;
308 	struct net *net;
309 	struct Qdisc *q;
310 	struct list_head cb_list;
311 	struct list_head owner_list;
312 	bool keep_dst;
313 	unsigned int offloadcnt; /* Number of oddloaded filters */
314 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
315 };
316 
317 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
318 {
319 	if (*flags & TCA_CLS_FLAGS_IN_HW)
320 		return;
321 	*flags |= TCA_CLS_FLAGS_IN_HW;
322 	block->offloadcnt++;
323 }
324 
325 static inline void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
326 {
327 	if (!(*flags & TCA_CLS_FLAGS_IN_HW))
328 		return;
329 	*flags &= ~TCA_CLS_FLAGS_IN_HW;
330 	block->offloadcnt--;
331 }
332 
333 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
334 {
335 	struct qdisc_skb_cb *qcb;
336 
337 	BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
338 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
339 }
340 
341 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
342 {
343 	return this_cpu_ptr(q->cpu_qstats)->qlen;
344 }
345 
346 static inline int qdisc_qlen(const struct Qdisc *q)
347 {
348 	return q->q.qlen;
349 }
350 
351 static inline int qdisc_qlen_sum(const struct Qdisc *q)
352 {
353 	__u32 qlen = q->qstats.qlen;
354 	int i;
355 
356 	if (q->flags & TCQ_F_NOLOCK) {
357 		for_each_possible_cpu(i)
358 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
359 	} else {
360 		qlen += q->q.qlen;
361 	}
362 
363 	return qlen;
364 }
365 
366 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
367 {
368 	return (struct qdisc_skb_cb *)skb->cb;
369 }
370 
371 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
372 {
373 	return &qdisc->q.lock;
374 }
375 
376 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
377 {
378 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
379 
380 	return q;
381 }
382 
383 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
384 {
385 	return qdisc->dev_queue->qdisc_sleeping;
386 }
387 
388 /* The qdisc root lock is a mechanism by which to top level
389  * of a qdisc tree can be locked from any qdisc node in the
390  * forest.  This allows changing the configuration of some
391  * aspect of the qdisc tree while blocking out asynchronous
392  * qdisc access in the packet processing paths.
393  *
394  * It is only legal to do this when the root will not change
395  * on us.  Otherwise we'll potentially lock the wrong qdisc
396  * root.  This is enforced by holding the RTNL semaphore, which
397  * all users of this lock accessor must do.
398  */
399 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
400 {
401 	struct Qdisc *root = qdisc_root(qdisc);
402 
403 	ASSERT_RTNL();
404 	return qdisc_lock(root);
405 }
406 
407 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
408 {
409 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
410 
411 	ASSERT_RTNL();
412 	return qdisc_lock(root);
413 }
414 
415 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
416 {
417 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
418 
419 	ASSERT_RTNL();
420 	return &root->running;
421 }
422 
423 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
424 {
425 	return qdisc->dev_queue->dev;
426 }
427 
428 static inline void sch_tree_lock(const struct Qdisc *q)
429 {
430 	spin_lock_bh(qdisc_root_sleeping_lock(q));
431 }
432 
433 static inline void sch_tree_unlock(const struct Qdisc *q)
434 {
435 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
436 }
437 
438 extern struct Qdisc noop_qdisc;
439 extern struct Qdisc_ops noop_qdisc_ops;
440 extern struct Qdisc_ops pfifo_fast_ops;
441 extern struct Qdisc_ops mq_qdisc_ops;
442 extern struct Qdisc_ops noqueue_qdisc_ops;
443 extern const struct Qdisc_ops *default_qdisc_ops;
444 static inline const struct Qdisc_ops *
445 get_default_qdisc_ops(const struct net_device *dev, int ntx)
446 {
447 	return ntx < dev->real_num_tx_queues ?
448 			default_qdisc_ops : &pfifo_fast_ops;
449 }
450 
451 struct Qdisc_class_common {
452 	u32			classid;
453 	struct hlist_node	hnode;
454 };
455 
456 struct Qdisc_class_hash {
457 	struct hlist_head	*hash;
458 	unsigned int		hashsize;
459 	unsigned int		hashmask;
460 	unsigned int		hashelems;
461 };
462 
463 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
464 {
465 	id ^= id >> 8;
466 	id ^= id >> 4;
467 	return id & mask;
468 }
469 
470 static inline struct Qdisc_class_common *
471 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
472 {
473 	struct Qdisc_class_common *cl;
474 	unsigned int h;
475 
476 	if (!id)
477 		return NULL;
478 
479 	h = qdisc_class_hash(id, hash->hashmask);
480 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
481 		if (cl->classid == id)
482 			return cl;
483 	}
484 	return NULL;
485 }
486 
487 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
488 {
489 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
490 
491 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
492 }
493 
494 int qdisc_class_hash_init(struct Qdisc_class_hash *);
495 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
496 			     struct Qdisc_class_common *);
497 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
498 			     struct Qdisc_class_common *);
499 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
500 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
501 
502 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
503 void dev_init_scheduler(struct net_device *dev);
504 void dev_shutdown(struct net_device *dev);
505 void dev_activate(struct net_device *dev);
506 void dev_deactivate(struct net_device *dev);
507 void dev_deactivate_many(struct list_head *head);
508 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
509 			      struct Qdisc *qdisc);
510 void qdisc_reset(struct Qdisc *qdisc);
511 void qdisc_destroy(struct Qdisc *qdisc);
512 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
513 			       unsigned int len);
514 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
515 			  const struct Qdisc_ops *ops,
516 			  struct netlink_ext_ack *extack);
517 void qdisc_free(struct Qdisc *qdisc);
518 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
519 				const struct Qdisc_ops *ops, u32 parentid,
520 				struct netlink_ext_ack *extack);
521 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
522 			       const struct qdisc_size_table *stab);
523 int skb_do_redirect(struct sk_buff *);
524 
525 static inline void skb_reset_tc(struct sk_buff *skb)
526 {
527 #ifdef CONFIG_NET_CLS_ACT
528 	skb->tc_redirected = 0;
529 #endif
530 }
531 
532 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
533 {
534 #ifdef CONFIG_NET_CLS_ACT
535 	return skb->tc_at_ingress;
536 #else
537 	return false;
538 #endif
539 }
540 
541 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
542 {
543 #ifdef CONFIG_NET_CLS_ACT
544 	if (skb->tc_skip_classify) {
545 		skb->tc_skip_classify = 0;
546 		return true;
547 	}
548 #endif
549 	return false;
550 }
551 
552 /* Reset all TX qdiscs greater than index of a device.  */
553 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
554 {
555 	struct Qdisc *qdisc;
556 
557 	for (; i < dev->num_tx_queues; i++) {
558 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
559 		if (qdisc) {
560 			spin_lock_bh(qdisc_lock(qdisc));
561 			qdisc_reset(qdisc);
562 			spin_unlock_bh(qdisc_lock(qdisc));
563 		}
564 	}
565 }
566 
567 static inline void qdisc_reset_all_tx(struct net_device *dev)
568 {
569 	qdisc_reset_all_tx_gt(dev, 0);
570 }
571 
572 /* Are all TX queues of the device empty?  */
573 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
574 {
575 	unsigned int i;
576 
577 	rcu_read_lock();
578 	for (i = 0; i < dev->num_tx_queues; i++) {
579 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
580 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
581 
582 		if (q->q.qlen) {
583 			rcu_read_unlock();
584 			return false;
585 		}
586 	}
587 	rcu_read_unlock();
588 	return true;
589 }
590 
591 /* Are any of the TX qdiscs changing?  */
592 static inline bool qdisc_tx_changing(const struct net_device *dev)
593 {
594 	unsigned int i;
595 
596 	for (i = 0; i < dev->num_tx_queues; i++) {
597 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
598 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
599 			return true;
600 	}
601 	return false;
602 }
603 
604 /* Is the device using the noop qdisc on all queues?  */
605 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
606 {
607 	unsigned int i;
608 
609 	for (i = 0; i < dev->num_tx_queues; i++) {
610 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
611 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
612 			return false;
613 	}
614 	return true;
615 }
616 
617 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
618 {
619 	return qdisc_skb_cb(skb)->pkt_len;
620 }
621 
622 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
623 enum net_xmit_qdisc_t {
624 	__NET_XMIT_STOLEN = 0x00010000,
625 	__NET_XMIT_BYPASS = 0x00020000,
626 };
627 
628 #ifdef CONFIG_NET_CLS_ACT
629 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
630 #else
631 #define net_xmit_drop_count(e)	(1)
632 #endif
633 
634 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
635 					   const struct Qdisc *sch)
636 {
637 #ifdef CONFIG_NET_SCHED
638 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
639 
640 	if (stab)
641 		__qdisc_calculate_pkt_len(skb, stab);
642 #endif
643 }
644 
645 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
646 				struct sk_buff **to_free)
647 {
648 	qdisc_calculate_pkt_len(skb, sch);
649 	return sch->enqueue(skb, sch, to_free);
650 }
651 
652 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
653 {
654 	return q->flags & TCQ_F_CPUSTATS;
655 }
656 
657 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
658 				  __u64 bytes, __u32 packets)
659 {
660 	bstats->bytes += bytes;
661 	bstats->packets += packets;
662 }
663 
664 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
665 				 const struct sk_buff *skb)
666 {
667 	_bstats_update(bstats,
668 		       qdisc_pkt_len(skb),
669 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
670 }
671 
672 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
673 				      __u64 bytes, __u32 packets)
674 {
675 	u64_stats_update_begin(&bstats->syncp);
676 	_bstats_update(&bstats->bstats, bytes, packets);
677 	u64_stats_update_end(&bstats->syncp);
678 }
679 
680 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
681 				     const struct sk_buff *skb)
682 {
683 	u64_stats_update_begin(&bstats->syncp);
684 	bstats_update(&bstats->bstats, skb);
685 	u64_stats_update_end(&bstats->syncp);
686 }
687 
688 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
689 					   const struct sk_buff *skb)
690 {
691 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
692 }
693 
694 static inline void qdisc_bstats_update(struct Qdisc *sch,
695 				       const struct sk_buff *skb)
696 {
697 	bstats_update(&sch->bstats, skb);
698 }
699 
700 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
701 					    const struct sk_buff *skb)
702 {
703 	sch->qstats.backlog -= qdisc_pkt_len(skb);
704 }
705 
706 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
707 						const struct sk_buff *skb)
708 {
709 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
710 }
711 
712 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
713 					    const struct sk_buff *skb)
714 {
715 	sch->qstats.backlog += qdisc_pkt_len(skb);
716 }
717 
718 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
719 						const struct sk_buff *skb)
720 {
721 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
722 }
723 
724 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
725 {
726 	this_cpu_inc(sch->cpu_qstats->qlen);
727 }
728 
729 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
730 {
731 	this_cpu_dec(sch->cpu_qstats->qlen);
732 }
733 
734 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
735 {
736 	this_cpu_inc(sch->cpu_qstats->requeues);
737 }
738 
739 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
740 {
741 	sch->qstats.drops += count;
742 }
743 
744 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
745 {
746 	qstats->drops++;
747 }
748 
749 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
750 {
751 	qstats->overlimits++;
752 }
753 
754 static inline void qdisc_qstats_drop(struct Qdisc *sch)
755 {
756 	qstats_drop_inc(&sch->qstats);
757 }
758 
759 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
760 {
761 	this_cpu_inc(sch->cpu_qstats->drops);
762 }
763 
764 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
765 {
766 	sch->qstats.overlimits++;
767 }
768 
769 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
770 {
771 	qh->head = NULL;
772 	qh->tail = NULL;
773 	qh->qlen = 0;
774 }
775 
776 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
777 				       struct qdisc_skb_head *qh)
778 {
779 	struct sk_buff *last = qh->tail;
780 
781 	if (last) {
782 		skb->next = NULL;
783 		last->next = skb;
784 		qh->tail = skb;
785 	} else {
786 		qh->tail = skb;
787 		qh->head = skb;
788 	}
789 	qh->qlen++;
790 	qdisc_qstats_backlog_inc(sch, skb);
791 
792 	return NET_XMIT_SUCCESS;
793 }
794 
795 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
796 {
797 	return __qdisc_enqueue_tail(skb, sch, &sch->q);
798 }
799 
800 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
801 {
802 	struct sk_buff *skb = qh->head;
803 
804 	if (likely(skb != NULL)) {
805 		qh->head = skb->next;
806 		qh->qlen--;
807 		if (qh->head == NULL)
808 			qh->tail = NULL;
809 		skb->next = NULL;
810 	}
811 
812 	return skb;
813 }
814 
815 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
816 {
817 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
818 
819 	if (likely(skb != NULL)) {
820 		qdisc_qstats_backlog_dec(sch, skb);
821 		qdisc_bstats_update(sch, skb);
822 	}
823 
824 	return skb;
825 }
826 
827 /* Instead of calling kfree_skb() while root qdisc lock is held,
828  * queue the skb for future freeing at end of __dev_xmit_skb()
829  */
830 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
831 {
832 	skb->next = *to_free;
833 	*to_free = skb;
834 }
835 
836 static inline void __qdisc_drop_all(struct sk_buff *skb,
837 				    struct sk_buff **to_free)
838 {
839 	if (skb->prev)
840 		skb->prev->next = *to_free;
841 	else
842 		skb->next = *to_free;
843 	*to_free = skb;
844 }
845 
846 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
847 						   struct qdisc_skb_head *qh,
848 						   struct sk_buff **to_free)
849 {
850 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
851 
852 	if (likely(skb != NULL)) {
853 		unsigned int len = qdisc_pkt_len(skb);
854 
855 		qdisc_qstats_backlog_dec(sch, skb);
856 		__qdisc_drop(skb, to_free);
857 		return len;
858 	}
859 
860 	return 0;
861 }
862 
863 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
864 						 struct sk_buff **to_free)
865 {
866 	return __qdisc_queue_drop_head(sch, &sch->q, to_free);
867 }
868 
869 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
870 {
871 	const struct qdisc_skb_head *qh = &sch->q;
872 
873 	return qh->head;
874 }
875 
876 /* generic pseudo peek method for non-work-conserving qdisc */
877 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
878 {
879 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
880 
881 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
882 	if (!skb) {
883 		skb = sch->dequeue(sch);
884 
885 		if (skb) {
886 			__skb_queue_head(&sch->gso_skb, skb);
887 			/* it's still part of the queue */
888 			qdisc_qstats_backlog_inc(sch, skb);
889 			sch->q.qlen++;
890 		}
891 	}
892 
893 	return skb;
894 }
895 
896 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
897 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
898 {
899 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
900 
901 	if (skb) {
902 		skb = __skb_dequeue(&sch->gso_skb);
903 		qdisc_qstats_backlog_dec(sch, skb);
904 		sch->q.qlen--;
905 	} else {
906 		skb = sch->dequeue(sch);
907 	}
908 
909 	return skb;
910 }
911 
912 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
913 {
914 	/*
915 	 * We do not know the backlog in bytes of this list, it
916 	 * is up to the caller to correct it
917 	 */
918 	ASSERT_RTNL();
919 	if (qh->qlen) {
920 		rtnl_kfree_skbs(qh->head, qh->tail);
921 
922 		qh->head = NULL;
923 		qh->tail = NULL;
924 		qh->qlen = 0;
925 	}
926 }
927 
928 static inline void qdisc_reset_queue(struct Qdisc *sch)
929 {
930 	__qdisc_reset_queue(&sch->q);
931 	sch->qstats.backlog = 0;
932 }
933 
934 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
935 					  struct Qdisc **pold)
936 {
937 	struct Qdisc *old;
938 
939 	sch_tree_lock(sch);
940 	old = *pold;
941 	*pold = new;
942 	if (old != NULL) {
943 		unsigned int qlen = old->q.qlen;
944 		unsigned int backlog = old->qstats.backlog;
945 
946 		qdisc_reset(old);
947 		qdisc_tree_reduce_backlog(old, qlen, backlog);
948 	}
949 	sch_tree_unlock(sch);
950 
951 	return old;
952 }
953 
954 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
955 {
956 	rtnl_kfree_skbs(skb, skb);
957 	qdisc_qstats_drop(sch);
958 }
959 
960 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
961 				 struct sk_buff **to_free)
962 {
963 	__qdisc_drop(skb, to_free);
964 	qdisc_qstats_cpu_drop(sch);
965 
966 	return NET_XMIT_DROP;
967 }
968 
969 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
970 			     struct sk_buff **to_free)
971 {
972 	__qdisc_drop(skb, to_free);
973 	qdisc_qstats_drop(sch);
974 
975 	return NET_XMIT_DROP;
976 }
977 
978 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
979 				 struct sk_buff **to_free)
980 {
981 	__qdisc_drop_all(skb, to_free);
982 	qdisc_qstats_drop(sch);
983 
984 	return NET_XMIT_DROP;
985 }
986 
987 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
988    long it will take to send a packet given its size.
989  */
990 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
991 {
992 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
993 	if (slot < 0)
994 		slot = 0;
995 	slot >>= rtab->rate.cell_log;
996 	if (slot > 255)
997 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
998 	return rtab->data[slot];
999 }
1000 
1001 struct psched_ratecfg {
1002 	u64	rate_bytes_ps; /* bytes per second */
1003 	u32	mult;
1004 	u16	overhead;
1005 	u8	linklayer;
1006 	u8	shift;
1007 };
1008 
1009 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1010 				unsigned int len)
1011 {
1012 	len += r->overhead;
1013 
1014 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1015 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1016 
1017 	return ((u64)len * r->mult) >> r->shift;
1018 }
1019 
1020 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1021 			       const struct tc_ratespec *conf,
1022 			       u64 rate64);
1023 
1024 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1025 					  const struct psched_ratecfg *r)
1026 {
1027 	memset(res, 0, sizeof(*res));
1028 
1029 	/* legacy struct tc_ratespec has a 32bit @rate field
1030 	 * Qdisc using 64bit rate should add new attributes
1031 	 * in order to maintain compatibility.
1032 	 */
1033 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1034 
1035 	res->overhead = r->overhead;
1036 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1037 }
1038 
1039 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1040  * The fast path only needs to access filter list and to update stats
1041  */
1042 struct mini_Qdisc {
1043 	struct tcf_proto *filter_list;
1044 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1045 	struct gnet_stats_queue	__percpu *cpu_qstats;
1046 	struct rcu_head rcu;
1047 };
1048 
1049 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1050 						const struct sk_buff *skb)
1051 {
1052 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1053 }
1054 
1055 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1056 {
1057 	this_cpu_inc(miniq->cpu_qstats->drops);
1058 }
1059 
1060 struct mini_Qdisc_pair {
1061 	struct mini_Qdisc miniq1;
1062 	struct mini_Qdisc miniq2;
1063 	struct mini_Qdisc __rcu **p_miniq;
1064 };
1065 
1066 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1067 			  struct tcf_proto *tp_head);
1068 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1069 			  struct mini_Qdisc __rcu **p_miniq);
1070 
1071 #endif
1072