xref: /openbmc/linux/include/net/sch_generic.h (revision 5b394b2d)
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 typedef int tc_setup_cb_t(enum tc_setup_type type,
24 			  void *type_data, void *cb_priv);
25 
26 struct qdisc_rate_table {
27 	struct tc_ratespec rate;
28 	u32		data[256];
29 	struct qdisc_rate_table *next;
30 	int		refcnt;
31 };
32 
33 enum qdisc_state_t {
34 	__QDISC_STATE_SCHED,
35 	__QDISC_STATE_DEACTIVATED,
36 };
37 
38 struct qdisc_size_table {
39 	struct rcu_head		rcu;
40 	struct list_head	list;
41 	struct tc_sizespec	szopts;
42 	int			refcnt;
43 	u16			data[];
44 };
45 
46 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
47 struct qdisc_skb_head {
48 	struct sk_buff	*head;
49 	struct sk_buff	*tail;
50 	__u32		qlen;
51 	spinlock_t	lock;
52 };
53 
54 struct Qdisc {
55 	int 			(*enqueue)(struct sk_buff *skb,
56 					   struct Qdisc *sch,
57 					   struct sk_buff **to_free);
58 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
59 	unsigned int		flags;
60 #define TCQ_F_BUILTIN		1
61 #define TCQ_F_INGRESS		2
62 #define TCQ_F_CAN_BYPASS	4
63 #define TCQ_F_MQROOT		8
64 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
65 				      * q->dev_queue : It can test
66 				      * netif_xmit_frozen_or_stopped() before
67 				      * dequeueing next packet.
68 				      * Its true for MQ/MQPRIO slaves, or non
69 				      * multiqueue device.
70 				      */
71 #define TCQ_F_WARN_NONWC	(1 << 16)
72 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
73 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
74 				      * qdisc_tree_decrease_qlen() should stop.
75 				      */
76 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
77 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
78 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
79 	u32			limit;
80 	const struct Qdisc_ops	*ops;
81 	struct qdisc_size_table	__rcu *stab;
82 	struct hlist_node       hash;
83 	u32			handle;
84 	u32			parent;
85 
86 	struct netdev_queue	*dev_queue;
87 
88 	struct net_rate_estimator __rcu *rate_est;
89 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
90 	struct gnet_stats_queue	__percpu *cpu_qstats;
91 	int			padded;
92 	refcount_t		refcnt;
93 
94 	/*
95 	 * For performance sake on SMP, we put highly modified fields at the end
96 	 */
97 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
98 	struct qdisc_skb_head	q;
99 	struct gnet_stats_basic_packed bstats;
100 	seqcount_t		running;
101 	struct gnet_stats_queue	qstats;
102 	unsigned long		state;
103 	struct Qdisc            *next_sched;
104 	struct sk_buff_head	skb_bad_txq;
105 
106 	spinlock_t		busylock ____cacheline_aligned_in_smp;
107 	spinlock_t		seqlock;
108 };
109 
110 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
111 {
112 	if (qdisc->flags & TCQ_F_BUILTIN)
113 		return;
114 	refcount_inc(&qdisc->refcnt);
115 }
116 
117 static inline bool qdisc_is_running(struct Qdisc *qdisc)
118 {
119 	if (qdisc->flags & TCQ_F_NOLOCK)
120 		return spin_is_locked(&qdisc->seqlock);
121 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
122 }
123 
124 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
125 {
126 	if (qdisc->flags & TCQ_F_NOLOCK) {
127 		if (!spin_trylock(&qdisc->seqlock))
128 			return false;
129 	} else if (qdisc_is_running(qdisc)) {
130 		return false;
131 	}
132 	/* Variant of write_seqcount_begin() telling lockdep a trylock
133 	 * was attempted.
134 	 */
135 	raw_write_seqcount_begin(&qdisc->running);
136 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
137 	return true;
138 }
139 
140 static inline void qdisc_run_end(struct Qdisc *qdisc)
141 {
142 	write_seqcount_end(&qdisc->running);
143 	if (qdisc->flags & TCQ_F_NOLOCK)
144 		spin_unlock(&qdisc->seqlock);
145 }
146 
147 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
148 {
149 	return qdisc->flags & TCQ_F_ONETXQUEUE;
150 }
151 
152 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
153 {
154 #ifdef CONFIG_BQL
155 	/* Non-BQL migrated drivers will return 0, too. */
156 	return dql_avail(&txq->dql);
157 #else
158 	return 0;
159 #endif
160 }
161 
162 struct Qdisc_class_ops {
163 	/* Child qdisc manipulation */
164 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
165 	int			(*graft)(struct Qdisc *, unsigned long cl,
166 					struct Qdisc *, struct Qdisc **,
167 					struct netlink_ext_ack *extack);
168 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
169 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
170 
171 	/* Class manipulation routines */
172 	unsigned long		(*find)(struct Qdisc *, u32 classid);
173 	int			(*change)(struct Qdisc *, u32, u32,
174 					struct nlattr **, unsigned long *,
175 					struct netlink_ext_ack *);
176 	int			(*delete)(struct Qdisc *, unsigned long);
177 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
178 
179 	/* Filter manipulation */
180 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
181 					     unsigned long arg,
182 					     struct netlink_ext_ack *extack);
183 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
184 					u32 classid);
185 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
186 
187 	/* rtnetlink specific */
188 	int			(*dump)(struct Qdisc *, unsigned long,
189 					struct sk_buff *skb, struct tcmsg*);
190 	int			(*dump_stats)(struct Qdisc *, unsigned long,
191 					struct gnet_dump *);
192 };
193 
194 struct Qdisc_ops {
195 	struct Qdisc_ops	*next;
196 	const struct Qdisc_class_ops	*cl_ops;
197 	char			id[IFNAMSIZ];
198 	int			priv_size;
199 	unsigned int		static_flags;
200 
201 	int 			(*enqueue)(struct sk_buff *skb,
202 					   struct Qdisc *sch,
203 					   struct sk_buff **to_free);
204 	struct sk_buff *	(*dequeue)(struct Qdisc *);
205 	struct sk_buff *	(*peek)(struct Qdisc *);
206 
207 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
208 					struct netlink_ext_ack *extack);
209 	void			(*reset)(struct Qdisc *);
210 	void			(*destroy)(struct Qdisc *);
211 	int			(*change)(struct Qdisc *sch,
212 					  struct nlattr *arg,
213 					  struct netlink_ext_ack *extack);
214 	void			(*attach)(struct Qdisc *sch);
215 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
216 
217 	int			(*dump)(struct Qdisc *, struct sk_buff *);
218 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
219 
220 	void			(*ingress_block_set)(struct Qdisc *sch,
221 						     u32 block_index);
222 	void			(*egress_block_set)(struct Qdisc *sch,
223 						    u32 block_index);
224 	u32			(*ingress_block_get)(struct Qdisc *sch);
225 	u32			(*egress_block_get)(struct Qdisc *sch);
226 
227 	struct module		*owner;
228 };
229 
230 
231 struct tcf_result {
232 	union {
233 		struct {
234 			unsigned long	class;
235 			u32		classid;
236 		};
237 		const struct tcf_proto *goto_tp;
238 
239 		/* used by the TC_ACT_REINSERT action */
240 		struct {
241 			bool		ingress;
242 			struct gnet_stats_queue *qstats;
243 		};
244 	};
245 };
246 
247 struct tcf_chain;
248 
249 struct tcf_proto_ops {
250 	struct list_head	head;
251 	char			kind[IFNAMSIZ];
252 
253 	int			(*classify)(struct sk_buff *,
254 					    const struct tcf_proto *,
255 					    struct tcf_result *);
256 	int			(*init)(struct tcf_proto*);
257 	void			(*destroy)(struct tcf_proto *tp,
258 					   struct netlink_ext_ack *extack);
259 
260 	void*			(*get)(struct tcf_proto*, u32 handle);
261 	int			(*change)(struct net *net, struct sk_buff *,
262 					struct tcf_proto*, unsigned long,
263 					u32 handle, struct nlattr **,
264 					void **, bool,
265 					struct netlink_ext_ack *);
266 	int			(*delete)(struct tcf_proto *tp, void *arg,
267 					  bool *last,
268 					  struct netlink_ext_ack *);
269 	void			(*walk)(struct tcf_proto*, struct tcf_walker *arg);
270 	int			(*reoffload)(struct tcf_proto *tp, bool add,
271 					     tc_setup_cb_t *cb, void *cb_priv,
272 					     struct netlink_ext_ack *extack);
273 	void			(*bind_class)(void *, u32, unsigned long);
274 	void *			(*tmplt_create)(struct net *net,
275 						struct tcf_chain *chain,
276 						struct nlattr **tca,
277 						struct netlink_ext_ack *extack);
278 	void			(*tmplt_destroy)(void *tmplt_priv);
279 
280 	/* rtnetlink specific */
281 	int			(*dump)(struct net*, struct tcf_proto*, void *,
282 					struct sk_buff *skb, struct tcmsg*);
283 	int			(*tmplt_dump)(struct sk_buff *skb,
284 					      struct net *net,
285 					      void *tmplt_priv);
286 
287 	struct module		*owner;
288 };
289 
290 struct tcf_proto {
291 	/* Fast access part */
292 	struct tcf_proto __rcu	*next;
293 	void __rcu		*root;
294 
295 	/* called under RCU BH lock*/
296 	int			(*classify)(struct sk_buff *,
297 					    const struct tcf_proto *,
298 					    struct tcf_result *);
299 	__be16			protocol;
300 
301 	/* All the rest */
302 	u32			prio;
303 	void			*data;
304 	const struct tcf_proto_ops	*ops;
305 	struct tcf_chain	*chain;
306 	struct rcu_head		rcu;
307 };
308 
309 struct qdisc_skb_cb {
310 	unsigned int		pkt_len;
311 	u16			slave_dev_queue_mapping;
312 	u16			tc_classid;
313 #define QDISC_CB_PRIV_LEN 20
314 	unsigned char		data[QDISC_CB_PRIV_LEN];
315 };
316 
317 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
318 
319 struct tcf_chain {
320 	struct tcf_proto __rcu *filter_chain;
321 	struct list_head list;
322 	struct tcf_block *block;
323 	u32 index; /* chain index */
324 	unsigned int refcnt;
325 	unsigned int action_refcnt;
326 	bool explicitly_created;
327 	const struct tcf_proto_ops *tmplt_ops;
328 	void *tmplt_priv;
329 };
330 
331 struct tcf_block {
332 	struct list_head chain_list;
333 	u32 index; /* block index for shared blocks */
334 	unsigned int refcnt;
335 	struct net *net;
336 	struct Qdisc *q;
337 	struct list_head cb_list;
338 	struct list_head owner_list;
339 	bool keep_dst;
340 	unsigned int offloadcnt; /* Number of oddloaded filters */
341 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
342 	struct {
343 		struct tcf_chain *chain;
344 		struct list_head filter_chain_list;
345 	} chain0;
346 };
347 
348 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
349 {
350 	if (*flags & TCA_CLS_FLAGS_IN_HW)
351 		return;
352 	*flags |= TCA_CLS_FLAGS_IN_HW;
353 	block->offloadcnt++;
354 }
355 
356 static inline void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
357 {
358 	if (!(*flags & TCA_CLS_FLAGS_IN_HW))
359 		return;
360 	*flags &= ~TCA_CLS_FLAGS_IN_HW;
361 	block->offloadcnt--;
362 }
363 
364 static inline void
365 tc_cls_offload_cnt_update(struct tcf_block *block, unsigned int *cnt,
366 			  u32 *flags, bool add)
367 {
368 	if (add) {
369 		if (!*cnt)
370 			tcf_block_offload_inc(block, flags);
371 		(*cnt)++;
372 	} else {
373 		(*cnt)--;
374 		if (!*cnt)
375 			tcf_block_offload_dec(block, flags);
376 	}
377 }
378 
379 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
380 {
381 	struct qdisc_skb_cb *qcb;
382 
383 	BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
384 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
385 }
386 
387 static inline int qdisc_qlen_cpu(const struct Qdisc *q)
388 {
389 	return this_cpu_ptr(q->cpu_qstats)->qlen;
390 }
391 
392 static inline int qdisc_qlen(const struct Qdisc *q)
393 {
394 	return q->q.qlen;
395 }
396 
397 static inline int qdisc_qlen_sum(const struct Qdisc *q)
398 {
399 	__u32 qlen = q->qstats.qlen;
400 	int i;
401 
402 	if (q->flags & TCQ_F_NOLOCK) {
403 		for_each_possible_cpu(i)
404 			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
405 	} else {
406 		qlen += q->q.qlen;
407 	}
408 
409 	return qlen;
410 }
411 
412 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
413 {
414 	return (struct qdisc_skb_cb *)skb->cb;
415 }
416 
417 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
418 {
419 	return &qdisc->q.lock;
420 }
421 
422 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
423 {
424 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
425 
426 	return q;
427 }
428 
429 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
430 {
431 	return qdisc->dev_queue->qdisc_sleeping;
432 }
433 
434 /* The qdisc root lock is a mechanism by which to top level
435  * of a qdisc tree can be locked from any qdisc node in the
436  * forest.  This allows changing the configuration of some
437  * aspect of the qdisc tree while blocking out asynchronous
438  * qdisc access in the packet processing paths.
439  *
440  * It is only legal to do this when the root will not change
441  * on us.  Otherwise we'll potentially lock the wrong qdisc
442  * root.  This is enforced by holding the RTNL semaphore, which
443  * all users of this lock accessor must do.
444  */
445 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
446 {
447 	struct Qdisc *root = qdisc_root(qdisc);
448 
449 	ASSERT_RTNL();
450 	return qdisc_lock(root);
451 }
452 
453 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
454 {
455 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
456 
457 	ASSERT_RTNL();
458 	return qdisc_lock(root);
459 }
460 
461 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
462 {
463 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
464 
465 	ASSERT_RTNL();
466 	return &root->running;
467 }
468 
469 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
470 {
471 	return qdisc->dev_queue->dev;
472 }
473 
474 static inline void sch_tree_lock(const struct Qdisc *q)
475 {
476 	spin_lock_bh(qdisc_root_sleeping_lock(q));
477 }
478 
479 static inline void sch_tree_unlock(const struct Qdisc *q)
480 {
481 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
482 }
483 
484 extern struct Qdisc noop_qdisc;
485 extern struct Qdisc_ops noop_qdisc_ops;
486 extern struct Qdisc_ops pfifo_fast_ops;
487 extern struct Qdisc_ops mq_qdisc_ops;
488 extern struct Qdisc_ops noqueue_qdisc_ops;
489 extern const struct Qdisc_ops *default_qdisc_ops;
490 static inline const struct Qdisc_ops *
491 get_default_qdisc_ops(const struct net_device *dev, int ntx)
492 {
493 	return ntx < dev->real_num_tx_queues ?
494 			default_qdisc_ops : &pfifo_fast_ops;
495 }
496 
497 struct Qdisc_class_common {
498 	u32			classid;
499 	struct hlist_node	hnode;
500 };
501 
502 struct Qdisc_class_hash {
503 	struct hlist_head	*hash;
504 	unsigned int		hashsize;
505 	unsigned int		hashmask;
506 	unsigned int		hashelems;
507 };
508 
509 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
510 {
511 	id ^= id >> 8;
512 	id ^= id >> 4;
513 	return id & mask;
514 }
515 
516 static inline struct Qdisc_class_common *
517 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
518 {
519 	struct Qdisc_class_common *cl;
520 	unsigned int h;
521 
522 	if (!id)
523 		return NULL;
524 
525 	h = qdisc_class_hash(id, hash->hashmask);
526 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
527 		if (cl->classid == id)
528 			return cl;
529 	}
530 	return NULL;
531 }
532 
533 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
534 {
535 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
536 
537 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
538 }
539 
540 int qdisc_class_hash_init(struct Qdisc_class_hash *);
541 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
542 			     struct Qdisc_class_common *);
543 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
544 			     struct Qdisc_class_common *);
545 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
546 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
547 
548 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
549 void dev_init_scheduler(struct net_device *dev);
550 void dev_shutdown(struct net_device *dev);
551 void dev_activate(struct net_device *dev);
552 void dev_deactivate(struct net_device *dev);
553 void dev_deactivate_many(struct list_head *head);
554 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
555 			      struct Qdisc *qdisc);
556 void qdisc_reset(struct Qdisc *qdisc);
557 void qdisc_destroy(struct Qdisc *qdisc);
558 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
559 			       unsigned int len);
560 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
561 			  const struct Qdisc_ops *ops,
562 			  struct netlink_ext_ack *extack);
563 void qdisc_free(struct Qdisc *qdisc);
564 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
565 				const struct Qdisc_ops *ops, u32 parentid,
566 				struct netlink_ext_ack *extack);
567 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
568 			       const struct qdisc_size_table *stab);
569 int skb_do_redirect(struct sk_buff *);
570 
571 static inline void skb_reset_tc(struct sk_buff *skb)
572 {
573 #ifdef CONFIG_NET_CLS_ACT
574 	skb->tc_redirected = 0;
575 #endif
576 }
577 
578 static inline bool skb_is_tc_redirected(const struct sk_buff *skb)
579 {
580 #ifdef CONFIG_NET_CLS_ACT
581 	return skb->tc_redirected;
582 #else
583 	return false;
584 #endif
585 }
586 
587 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
588 {
589 #ifdef CONFIG_NET_CLS_ACT
590 	return skb->tc_at_ingress;
591 #else
592 	return false;
593 #endif
594 }
595 
596 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
597 {
598 #ifdef CONFIG_NET_CLS_ACT
599 	if (skb->tc_skip_classify) {
600 		skb->tc_skip_classify = 0;
601 		return true;
602 	}
603 #endif
604 	return false;
605 }
606 
607 /* Reset all TX qdiscs greater than index of a device.  */
608 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
609 {
610 	struct Qdisc *qdisc;
611 
612 	for (; i < dev->num_tx_queues; i++) {
613 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
614 		if (qdisc) {
615 			spin_lock_bh(qdisc_lock(qdisc));
616 			qdisc_reset(qdisc);
617 			spin_unlock_bh(qdisc_lock(qdisc));
618 		}
619 	}
620 }
621 
622 static inline void qdisc_reset_all_tx(struct net_device *dev)
623 {
624 	qdisc_reset_all_tx_gt(dev, 0);
625 }
626 
627 /* Are all TX queues of the device empty?  */
628 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
629 {
630 	unsigned int i;
631 
632 	rcu_read_lock();
633 	for (i = 0; i < dev->num_tx_queues; i++) {
634 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
635 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
636 
637 		if (q->q.qlen) {
638 			rcu_read_unlock();
639 			return false;
640 		}
641 	}
642 	rcu_read_unlock();
643 	return true;
644 }
645 
646 /* Are any of the TX qdiscs changing?  */
647 static inline bool qdisc_tx_changing(const struct net_device *dev)
648 {
649 	unsigned int i;
650 
651 	for (i = 0; i < dev->num_tx_queues; i++) {
652 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
653 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
654 			return true;
655 	}
656 	return false;
657 }
658 
659 /* Is the device using the noop qdisc on all queues?  */
660 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
661 {
662 	unsigned int i;
663 
664 	for (i = 0; i < dev->num_tx_queues; i++) {
665 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
666 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
667 			return false;
668 	}
669 	return true;
670 }
671 
672 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
673 {
674 	return qdisc_skb_cb(skb)->pkt_len;
675 }
676 
677 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
678 enum net_xmit_qdisc_t {
679 	__NET_XMIT_STOLEN = 0x00010000,
680 	__NET_XMIT_BYPASS = 0x00020000,
681 };
682 
683 #ifdef CONFIG_NET_CLS_ACT
684 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
685 #else
686 #define net_xmit_drop_count(e)	(1)
687 #endif
688 
689 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
690 					   const struct Qdisc *sch)
691 {
692 #ifdef CONFIG_NET_SCHED
693 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
694 
695 	if (stab)
696 		__qdisc_calculate_pkt_len(skb, stab);
697 #endif
698 }
699 
700 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
701 				struct sk_buff **to_free)
702 {
703 	qdisc_calculate_pkt_len(skb, sch);
704 	return sch->enqueue(skb, sch, to_free);
705 }
706 
707 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
708 {
709 	return q->flags & TCQ_F_CPUSTATS;
710 }
711 
712 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
713 				  __u64 bytes, __u32 packets)
714 {
715 	bstats->bytes += bytes;
716 	bstats->packets += packets;
717 }
718 
719 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
720 				 const struct sk_buff *skb)
721 {
722 	_bstats_update(bstats,
723 		       qdisc_pkt_len(skb),
724 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
725 }
726 
727 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
728 				      __u64 bytes, __u32 packets)
729 {
730 	u64_stats_update_begin(&bstats->syncp);
731 	_bstats_update(&bstats->bstats, bytes, packets);
732 	u64_stats_update_end(&bstats->syncp);
733 }
734 
735 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
736 				     const struct sk_buff *skb)
737 {
738 	u64_stats_update_begin(&bstats->syncp);
739 	bstats_update(&bstats->bstats, skb);
740 	u64_stats_update_end(&bstats->syncp);
741 }
742 
743 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
744 					   const struct sk_buff *skb)
745 {
746 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
747 }
748 
749 static inline void qdisc_bstats_update(struct Qdisc *sch,
750 				       const struct sk_buff *skb)
751 {
752 	bstats_update(&sch->bstats, skb);
753 }
754 
755 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
756 					    const struct sk_buff *skb)
757 {
758 	sch->qstats.backlog -= qdisc_pkt_len(skb);
759 }
760 
761 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
762 						const struct sk_buff *skb)
763 {
764 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
765 }
766 
767 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
768 					    const struct sk_buff *skb)
769 {
770 	sch->qstats.backlog += qdisc_pkt_len(skb);
771 }
772 
773 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
774 						const struct sk_buff *skb)
775 {
776 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
777 }
778 
779 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
780 {
781 	this_cpu_inc(sch->cpu_qstats->qlen);
782 }
783 
784 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
785 {
786 	this_cpu_dec(sch->cpu_qstats->qlen);
787 }
788 
789 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
790 {
791 	this_cpu_inc(sch->cpu_qstats->requeues);
792 }
793 
794 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
795 {
796 	sch->qstats.drops += count;
797 }
798 
799 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
800 {
801 	qstats->drops++;
802 }
803 
804 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
805 {
806 	qstats->overlimits++;
807 }
808 
809 static inline void qdisc_qstats_drop(struct Qdisc *sch)
810 {
811 	qstats_drop_inc(&sch->qstats);
812 }
813 
814 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
815 {
816 	this_cpu_inc(sch->cpu_qstats->drops);
817 }
818 
819 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
820 {
821 	sch->qstats.overlimits++;
822 }
823 
824 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
825 {
826 	qh->head = NULL;
827 	qh->tail = NULL;
828 	qh->qlen = 0;
829 }
830 
831 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
832 				       struct qdisc_skb_head *qh)
833 {
834 	struct sk_buff *last = qh->tail;
835 
836 	if (last) {
837 		skb->next = NULL;
838 		last->next = skb;
839 		qh->tail = skb;
840 	} else {
841 		qh->tail = skb;
842 		qh->head = skb;
843 	}
844 	qh->qlen++;
845 	qdisc_qstats_backlog_inc(sch, skb);
846 
847 	return NET_XMIT_SUCCESS;
848 }
849 
850 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
851 {
852 	return __qdisc_enqueue_tail(skb, sch, &sch->q);
853 }
854 
855 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
856 {
857 	struct sk_buff *skb = qh->head;
858 
859 	if (likely(skb != NULL)) {
860 		qh->head = skb->next;
861 		qh->qlen--;
862 		if (qh->head == NULL)
863 			qh->tail = NULL;
864 		skb->next = NULL;
865 	}
866 
867 	return skb;
868 }
869 
870 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
871 {
872 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
873 
874 	if (likely(skb != NULL)) {
875 		qdisc_qstats_backlog_dec(sch, skb);
876 		qdisc_bstats_update(sch, skb);
877 	}
878 
879 	return skb;
880 }
881 
882 /* Instead of calling kfree_skb() while root qdisc lock is held,
883  * queue the skb for future freeing at end of __dev_xmit_skb()
884  */
885 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
886 {
887 	skb->next = *to_free;
888 	*to_free = skb;
889 }
890 
891 static inline void __qdisc_drop_all(struct sk_buff *skb,
892 				    struct sk_buff **to_free)
893 {
894 	if (skb->prev)
895 		skb->prev->next = *to_free;
896 	else
897 		skb->next = *to_free;
898 	*to_free = skb;
899 }
900 
901 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
902 						   struct qdisc_skb_head *qh,
903 						   struct sk_buff **to_free)
904 {
905 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
906 
907 	if (likely(skb != NULL)) {
908 		unsigned int len = qdisc_pkt_len(skb);
909 
910 		qdisc_qstats_backlog_dec(sch, skb);
911 		__qdisc_drop(skb, to_free);
912 		return len;
913 	}
914 
915 	return 0;
916 }
917 
918 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
919 						 struct sk_buff **to_free)
920 {
921 	return __qdisc_queue_drop_head(sch, &sch->q, to_free);
922 }
923 
924 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
925 {
926 	const struct qdisc_skb_head *qh = &sch->q;
927 
928 	return qh->head;
929 }
930 
931 /* generic pseudo peek method for non-work-conserving qdisc */
932 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
933 {
934 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
935 
936 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
937 	if (!skb) {
938 		skb = sch->dequeue(sch);
939 
940 		if (skb) {
941 			__skb_queue_head(&sch->gso_skb, skb);
942 			/* it's still part of the queue */
943 			qdisc_qstats_backlog_inc(sch, skb);
944 			sch->q.qlen++;
945 		}
946 	}
947 
948 	return skb;
949 }
950 
951 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
952 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
953 {
954 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
955 
956 	if (skb) {
957 		skb = __skb_dequeue(&sch->gso_skb);
958 		qdisc_qstats_backlog_dec(sch, skb);
959 		sch->q.qlen--;
960 	} else {
961 		skb = sch->dequeue(sch);
962 	}
963 
964 	return skb;
965 }
966 
967 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
968 {
969 	/*
970 	 * We do not know the backlog in bytes of this list, it
971 	 * is up to the caller to correct it
972 	 */
973 	ASSERT_RTNL();
974 	if (qh->qlen) {
975 		rtnl_kfree_skbs(qh->head, qh->tail);
976 
977 		qh->head = NULL;
978 		qh->tail = NULL;
979 		qh->qlen = 0;
980 	}
981 }
982 
983 static inline void qdisc_reset_queue(struct Qdisc *sch)
984 {
985 	__qdisc_reset_queue(&sch->q);
986 	sch->qstats.backlog = 0;
987 }
988 
989 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
990 					  struct Qdisc **pold)
991 {
992 	struct Qdisc *old;
993 
994 	sch_tree_lock(sch);
995 	old = *pold;
996 	*pold = new;
997 	if (old != NULL) {
998 		unsigned int qlen = old->q.qlen;
999 		unsigned int backlog = old->qstats.backlog;
1000 
1001 		qdisc_reset(old);
1002 		qdisc_tree_reduce_backlog(old, qlen, backlog);
1003 	}
1004 	sch_tree_unlock(sch);
1005 
1006 	return old;
1007 }
1008 
1009 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1010 {
1011 	rtnl_kfree_skbs(skb, skb);
1012 	qdisc_qstats_drop(sch);
1013 }
1014 
1015 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1016 				 struct sk_buff **to_free)
1017 {
1018 	__qdisc_drop(skb, to_free);
1019 	qdisc_qstats_cpu_drop(sch);
1020 
1021 	return NET_XMIT_DROP;
1022 }
1023 
1024 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1025 			     struct sk_buff **to_free)
1026 {
1027 	__qdisc_drop(skb, to_free);
1028 	qdisc_qstats_drop(sch);
1029 
1030 	return NET_XMIT_DROP;
1031 }
1032 
1033 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1034 				 struct sk_buff **to_free)
1035 {
1036 	__qdisc_drop_all(skb, to_free);
1037 	qdisc_qstats_drop(sch);
1038 
1039 	return NET_XMIT_DROP;
1040 }
1041 
1042 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1043    long it will take to send a packet given its size.
1044  */
1045 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1046 {
1047 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1048 	if (slot < 0)
1049 		slot = 0;
1050 	slot >>= rtab->rate.cell_log;
1051 	if (slot > 255)
1052 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1053 	return rtab->data[slot];
1054 }
1055 
1056 struct psched_ratecfg {
1057 	u64	rate_bytes_ps; /* bytes per second */
1058 	u32	mult;
1059 	u16	overhead;
1060 	u8	linklayer;
1061 	u8	shift;
1062 };
1063 
1064 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1065 				unsigned int len)
1066 {
1067 	len += r->overhead;
1068 
1069 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1070 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1071 
1072 	return ((u64)len * r->mult) >> r->shift;
1073 }
1074 
1075 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1076 			       const struct tc_ratespec *conf,
1077 			       u64 rate64);
1078 
1079 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1080 					  const struct psched_ratecfg *r)
1081 {
1082 	memset(res, 0, sizeof(*res));
1083 
1084 	/* legacy struct tc_ratespec has a 32bit @rate field
1085 	 * Qdisc using 64bit rate should add new attributes
1086 	 * in order to maintain compatibility.
1087 	 */
1088 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1089 
1090 	res->overhead = r->overhead;
1091 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1092 }
1093 
1094 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1095  * The fast path only needs to access filter list and to update stats
1096  */
1097 struct mini_Qdisc {
1098 	struct tcf_proto *filter_list;
1099 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1100 	struct gnet_stats_queue	__percpu *cpu_qstats;
1101 	struct rcu_head rcu;
1102 };
1103 
1104 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1105 						const struct sk_buff *skb)
1106 {
1107 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1108 }
1109 
1110 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1111 {
1112 	this_cpu_inc(miniq->cpu_qstats->drops);
1113 }
1114 
1115 struct mini_Qdisc_pair {
1116 	struct mini_Qdisc miniq1;
1117 	struct mini_Qdisc miniq2;
1118 	struct mini_Qdisc __rcu **p_miniq;
1119 };
1120 
1121 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1122 			  struct tcf_proto *tp_head);
1123 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1124 			  struct mini_Qdisc __rcu **p_miniq);
1125 
1126 static inline void skb_tc_reinsert(struct sk_buff *skb, struct tcf_result *res)
1127 {
1128 	struct gnet_stats_queue *stats = res->qstats;
1129 	int ret;
1130 
1131 	if (res->ingress)
1132 		ret = netif_receive_skb(skb);
1133 	else
1134 		ret = dev_queue_xmit(skb);
1135 	if (ret && stats)
1136 		qstats_overlimit_inc(res->qstats);
1137 }
1138 
1139 #endif
1140