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
23struct Qdisc_ops;
24struct qdisc_walker;
25struct tcf_walker;
26struct module;
27struct bpf_flow_keys;
28
29struct qdisc_rate_table {
30	struct tc_ratespec rate;
31	u32		data[256];
32	struct qdisc_rate_table *next;
33	int		refcnt;
34};
35
36enum qdisc_state_t {
37	__QDISC_STATE_SCHED,
38	__QDISC_STATE_DEACTIVATED,
39	__QDISC_STATE_MISSED,
40};
41
42struct qdisc_size_table {
43	struct rcu_head		rcu;
44	struct list_head	list;
45	struct tc_sizespec	szopts;
46	int			refcnt;
47	u16			data[];
48};
49
50/* similar to sk_buff_head, but skb->prev pointer is undefined. */
51struct qdisc_skb_head {
52	struct sk_buff	*head;
53	struct sk_buff	*tail;
54	__u32		qlen;
55	spinlock_t	lock;
56};
57
58struct Qdisc {
59	int 			(*enqueue)(struct sk_buff *skb,
60					   struct Qdisc *sch,
61					   struct sk_buff **to_free);
62	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
63	unsigned int		flags;
64#define TCQ_F_BUILTIN		1
65#define TCQ_F_INGRESS		2
66#define TCQ_F_CAN_BYPASS	4
67#define TCQ_F_MQROOT		8
68#define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
69				      * q->dev_queue : It can test
70				      * netif_xmit_frozen_or_stopped() before
71				      * dequeueing next packet.
72				      * Its true for MQ/MQPRIO slaves, or non
73				      * multiqueue device.
74				      */
75#define TCQ_F_WARN_NONWC	(1 << 16)
76#define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
77#define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
78				      * qdisc_tree_decrease_qlen() should stop.
79				      */
80#define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
81#define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
82#define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
83	u32			limit;
84	const struct Qdisc_ops	*ops;
85	struct qdisc_size_table	__rcu *stab;
86	struct hlist_node       hash;
87	u32			handle;
88	u32			parent;
89
90	struct netdev_queue	*dev_queue;
91
92	struct net_rate_estimator __rcu *rate_est;
93	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
94	struct gnet_stats_queue	__percpu *cpu_qstats;
95	int			pad;
96	refcount_t		refcnt;
97
98	/*
99	 * For performance sake on SMP, we put highly modified fields at the end
100	 */
101	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
102	struct qdisc_skb_head	q;
103	struct gnet_stats_basic_packed bstats;
104	seqcount_t		running;
105	struct gnet_stats_queue	qstats;
106	unsigned long		state;
107	struct Qdisc            *next_sched;
108	struct sk_buff_head	skb_bad_txq;
109
110	spinlock_t		busylock ____cacheline_aligned_in_smp;
111	spinlock_t		seqlock;
112
113	/* for NOLOCK qdisc, true if there are no enqueued skbs */
114	bool			empty;
115	struct rcu_head		rcu;
116
117	/* private data */
118	long privdata[] ____cacheline_aligned;
119};
120
121static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
122{
123	if (qdisc->flags & TCQ_F_BUILTIN)
124		return;
125	refcount_inc(&qdisc->refcnt);
126}
127
128/* Intended to be used by unlocked users, when concurrent qdisc release is
129 * possible.
130 */
131
132static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
133{
134	if (qdisc->flags & TCQ_F_BUILTIN)
135		return qdisc;
136	if (refcount_inc_not_zero(&qdisc->refcnt))
137		return qdisc;
138	return NULL;
139}
140
141static inline bool qdisc_is_running(struct Qdisc *qdisc)
142{
143	if (qdisc->flags & TCQ_F_NOLOCK)
144		return spin_is_locked(&qdisc->seqlock);
145	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
146}
147
148static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
149{
150	return q->flags & TCQ_F_CPUSTATS;
151}
152
153static inline bool qdisc_is_empty(const struct Qdisc *qdisc)
154{
155	if (qdisc_is_percpu_stats(qdisc))
156		return READ_ONCE(qdisc->empty);
157	return !READ_ONCE(qdisc->q.qlen);
158}
159
160static inline bool qdisc_run_begin(struct Qdisc *qdisc)
161{
162	if (qdisc->flags & TCQ_F_NOLOCK) {
163		if (spin_trylock(&qdisc->seqlock))
164			goto nolock_empty;
165
166		/* No need to insist if the MISSED flag was already set.
167		 * Note that test_and_set_bit() also gives us memory ordering
168		 * guarantees wrt potential earlier enqueue() and below
169		 * spin_trylock(), both of which are necessary to prevent races
170		 */
171		if (test_and_set_bit(__QDISC_STATE_MISSED, &qdisc->state))
172			return false;
173
174		/* Try to take the lock again to make sure that we will either
175		 * grab it or the CPU that still has it will see MISSED set
176		 * when testing it in qdisc_run_end()
177		 */
178		if (!spin_trylock(&qdisc->seqlock))
179			return false;
180
181nolock_empty:
182		WRITE_ONCE(qdisc->empty, false);
183	} else if (qdisc_is_running(qdisc)) {
184		return false;
185	}
186	/* Variant of write_seqcount_begin() telling lockdep a trylock
187	 * was attempted.
188	 */
189	raw_write_seqcount_begin(&qdisc->running);
190	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
191	return true;
192}
193
194static inline void qdisc_run_end(struct Qdisc *qdisc)
195{
196	write_seqcount_end(&qdisc->running);
197	if (qdisc->flags & TCQ_F_NOLOCK) {
198		spin_unlock(&qdisc->seqlock);
199
200		/* spin_unlock() only has store-release semantic. The unlock
201		 * and test_bit() ordering is a store-load ordering, so a full
202		 * memory barrier is needed here.
203		 */
204		smp_mb();
205
206		if (unlikely(test_bit(__QDISC_STATE_MISSED,
207				      &qdisc->state))) {
208			clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
209			__netif_schedule(qdisc);
210		}
211	}
212}
213
214static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
215{
216	return qdisc->flags & TCQ_F_ONETXQUEUE;
217}
218
219static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
220{
221#ifdef CONFIG_BQL
222	/* Non-BQL migrated drivers will return 0, too. */
223	return dql_avail(&txq->dql);
224#else
225	return 0;
226#endif
227}
228
229struct Qdisc_class_ops {
230	unsigned int		flags;
231	/* Child qdisc manipulation */
232	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
233	int			(*graft)(struct Qdisc *, unsigned long cl,
234					struct Qdisc *, struct Qdisc **,
235					struct netlink_ext_ack *extack);
236	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
237	void			(*qlen_notify)(struct Qdisc *, unsigned long);
238
239	/* Class manipulation routines */
240	unsigned long		(*find)(struct Qdisc *, u32 classid);
241	int			(*change)(struct Qdisc *, u32, u32,
242					struct nlattr **, unsigned long *,
243					struct netlink_ext_ack *);
244	int			(*delete)(struct Qdisc *, unsigned long);
245	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
246
247	/* Filter manipulation */
248	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
249					     unsigned long arg,
250					     struct netlink_ext_ack *extack);
251	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
252					u32 classid);
253	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
254
255	/* rtnetlink specific */
256	int			(*dump)(struct Qdisc *, unsigned long,
257					struct sk_buff *skb, struct tcmsg*);
258	int			(*dump_stats)(struct Qdisc *, unsigned long,
259					struct gnet_dump *);
260};
261
262/* Qdisc_class_ops flag values */
263
264/* Implements API that doesn't require rtnl lock */
265enum qdisc_class_ops_flags {
266	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
267};
268
269struct Qdisc_ops {
270	struct Qdisc_ops	*next;
271	const struct Qdisc_class_ops	*cl_ops;
272	char			id[IFNAMSIZ];
273	int			priv_size;
274	unsigned int		static_flags;
275
276	int 			(*enqueue)(struct sk_buff *skb,
277					   struct Qdisc *sch,
278					   struct sk_buff **to_free);
279	struct sk_buff *	(*dequeue)(struct Qdisc *);
280	struct sk_buff *	(*peek)(struct Qdisc *);
281
282	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
283					struct netlink_ext_ack *extack);
284	void			(*reset)(struct Qdisc *);
285	void			(*destroy)(struct Qdisc *);
286	int			(*change)(struct Qdisc *sch,
287					  struct nlattr *arg,
288					  struct netlink_ext_ack *extack);
289	void			(*attach)(struct Qdisc *sch);
290	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
291	void			(*change_real_num_tx)(struct Qdisc *sch,
292						      unsigned int new_real_tx);
293
294	int			(*dump)(struct Qdisc *, struct sk_buff *);
295	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
296
297	void			(*ingress_block_set)(struct Qdisc *sch,
298						     u32 block_index);
299	void			(*egress_block_set)(struct Qdisc *sch,
300						    u32 block_index);
301	u32			(*ingress_block_get)(struct Qdisc *sch);
302	u32			(*egress_block_get)(struct Qdisc *sch);
303
304	struct module		*owner;
305};
306
307
308struct tcf_result {
309	union {
310		struct {
311			unsigned long	class;
312			u32		classid;
313		};
314		const struct tcf_proto *goto_tp;
315
316		/* used in the skb_tc_reinsert function */
317		struct {
318			bool		ingress;
319			struct gnet_stats_queue *qstats;
320		};
321	};
322};
323
324struct tcf_chain;
325
326struct tcf_proto_ops {
327	struct list_head	head;
328	char			kind[IFNAMSIZ];
329
330	int			(*classify)(struct sk_buff *,
331					    const struct tcf_proto *,
332					    struct tcf_result *);
333	int			(*init)(struct tcf_proto*);
334	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
335					   struct netlink_ext_ack *extack);
336
337	void*			(*get)(struct tcf_proto*, u32 handle);
338	void			(*put)(struct tcf_proto *tp, void *f);
339	int			(*change)(struct net *net, struct sk_buff *,
340					struct tcf_proto*, unsigned long,
341					u32 handle, struct nlattr **,
342					void **, bool, bool,
343					struct netlink_ext_ack *);
344	int			(*delete)(struct tcf_proto *tp, void *arg,
345					  bool *last, bool rtnl_held,
346					  struct netlink_ext_ack *);
347	bool			(*delete_empty)(struct tcf_proto *tp);
348	void			(*walk)(struct tcf_proto *tp,
349					struct tcf_walker *arg, bool rtnl_held);
350	int			(*reoffload)(struct tcf_proto *tp, bool add,
351					     flow_setup_cb_t *cb, void *cb_priv,
352					     struct netlink_ext_ack *extack);
353	void			(*hw_add)(struct tcf_proto *tp,
354					  void *type_data);
355	void			(*hw_del)(struct tcf_proto *tp,
356					  void *type_data);
357	void			(*bind_class)(void *, u32, unsigned long,
358					      void *, unsigned long);
359	void *			(*tmplt_create)(struct net *net,
360						struct tcf_chain *chain,
361						struct nlattr **tca,
362						struct netlink_ext_ack *extack);
363	void			(*tmplt_destroy)(void *tmplt_priv);
364
365	/* rtnetlink specific */
366	int			(*dump)(struct net*, struct tcf_proto*, void *,
367					struct sk_buff *skb, struct tcmsg*,
368					bool);
369	int			(*terse_dump)(struct net *net,
370					      struct tcf_proto *tp, void *fh,
371					      struct sk_buff *skb,
372					      struct tcmsg *t, bool rtnl_held);
373	int			(*tmplt_dump)(struct sk_buff *skb,
374					      struct net *net,
375					      void *tmplt_priv);
376
377	struct module		*owner;
378	int			flags;
379};
380
381/* Classifiers setting TCF_PROTO_OPS_DOIT_UNLOCKED in tcf_proto_ops->flags
382 * are expected to implement tcf_proto_ops->delete_empty(), otherwise race
383 * conditions can occur when filters are inserted/deleted simultaneously.
384 */
385enum tcf_proto_ops_flags {
386	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
387};
388
389struct tcf_proto {
390	/* Fast access part */
391	struct tcf_proto __rcu	*next;
392	void __rcu		*root;
393
394	/* called under RCU BH lock*/
395	int			(*classify)(struct sk_buff *,
396					    const struct tcf_proto *,
397					    struct tcf_result *);
398	__be16			protocol;
399
400	/* All the rest */
401	u32			prio;
402	void			*data;
403	const struct tcf_proto_ops	*ops;
404	struct tcf_chain	*chain;
405	/* Lock protects tcf_proto shared state and can be used by unlocked
406	 * classifiers to protect their private data.
407	 */
408	spinlock_t		lock;
409	bool			deleting;
410	refcount_t		refcnt;
411	struct rcu_head		rcu;
412	struct hlist_node	destroy_ht_node;
413};
414
415struct qdisc_skb_cb {
416	struct {
417		unsigned int		pkt_len;
418		u16			slave_dev_queue_mapping;
419		u16			tc_classid;
420	};
421#define QDISC_CB_PRIV_LEN 20
422	unsigned char		data[QDISC_CB_PRIV_LEN];
423	u16			mru;
424};
425
426typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
427
428struct tcf_chain {
429	/* Protects filter_chain. */
430	struct mutex filter_chain_lock;
431	struct tcf_proto __rcu *filter_chain;
432	struct list_head list;
433	struct tcf_block *block;
434	u32 index; /* chain index */
435	unsigned int refcnt;
436	unsigned int action_refcnt;
437	bool explicitly_created;
438	bool flushing;
439	const struct tcf_proto_ops *tmplt_ops;
440	void *tmplt_priv;
441	struct rcu_head rcu;
442};
443
444struct tcf_block {
445	/* Lock protects tcf_block and lifetime-management data of chains
446	 * attached to the block (refcnt, action_refcnt, explicitly_created).
447	 */
448	struct mutex lock;
449	struct list_head chain_list;
450	u32 index; /* block index for shared blocks */
451	u32 classid; /* which class this block belongs to */
452	refcount_t refcnt;
453	struct net *net;
454	struct Qdisc *q;
455	struct rw_semaphore cb_lock; /* protects cb_list and offload counters */
456	struct flow_block flow_block;
457	struct list_head owner_list;
458	bool keep_dst;
459	atomic_t offloadcnt; /* Number of oddloaded filters */
460	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
461	unsigned int lockeddevcnt; /* Number of devs that require rtnl lock. */
462	struct {
463		struct tcf_chain *chain;
464		struct list_head filter_chain_list;
465	} chain0;
466	struct rcu_head rcu;
467	DECLARE_HASHTABLE(proto_destroy_ht, 7);
468	struct mutex proto_destroy_lock; /* Lock for proto_destroy hashtable. */
469};
470
471#ifdef CONFIG_PROVE_LOCKING
472static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
473{
474	return lockdep_is_held(&chain->filter_chain_lock);
475}
476
477static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
478{
479	return lockdep_is_held(&tp->lock);
480}
481#else
482static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
483{
484	return true;
485}
486
487static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
488{
489	return true;
490}
491#endif /* #ifdef CONFIG_PROVE_LOCKING */
492
493#define tcf_chain_dereference(p, chain)					\
494	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
495
496#define tcf_proto_dereference(p, tp)					\
497	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
498
499static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
500{
501	struct qdisc_skb_cb *qcb;
502
503	BUILD_BUG_ON(sizeof(skb->cb) < sizeof(*qcb));
504	BUILD_BUG_ON(sizeof(qcb->data) < sz);
505}
506
507static inline int qdisc_qlen_cpu(const struct Qdisc *q)
508{
509	return this_cpu_ptr(q->cpu_qstats)->qlen;
510}
511
512static inline int qdisc_qlen(const struct Qdisc *q)
513{
514	return q->q.qlen;
515}
516
517static inline int qdisc_qlen_sum(const struct Qdisc *q)
518{
519	__u32 qlen = q->qstats.qlen;
520	int i;
521
522	if (qdisc_is_percpu_stats(q)) {
523		for_each_possible_cpu(i)
524			qlen += per_cpu_ptr(q->cpu_qstats, i)->qlen;
525	} else {
526		qlen += q->q.qlen;
527	}
528
529	return qlen;
530}
531
532static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
533{
534	return (struct qdisc_skb_cb *)skb->cb;
535}
536
537static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
538{
539	return &qdisc->q.lock;
540}
541
542static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
543{
544	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
545
546	return q;
547}
548
549static inline struct Qdisc *qdisc_root_bh(const struct Qdisc *qdisc)
550{
551	return rcu_dereference_bh(qdisc->dev_queue->qdisc);
552}
553
554static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
555{
556	return qdisc->dev_queue->qdisc_sleeping;
557}
558
559/* The qdisc root lock is a mechanism by which to top level
560 * of a qdisc tree can be locked from any qdisc node in the
561 * forest.  This allows changing the configuration of some
562 * aspect of the qdisc tree while blocking out asynchronous
563 * qdisc access in the packet processing paths.
564 *
565 * It is only legal to do this when the root will not change
566 * on us.  Otherwise we'll potentially lock the wrong qdisc
567 * root.  This is enforced by holding the RTNL semaphore, which
568 * all users of this lock accessor must do.
569 */
570static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
571{
572	struct Qdisc *root = qdisc_root(qdisc);
573
574	ASSERT_RTNL();
575	return qdisc_lock(root);
576}
577
578static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
579{
580	struct Qdisc *root = qdisc_root_sleeping(qdisc);
581
582	ASSERT_RTNL();
583	return qdisc_lock(root);
584}
585
586static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
587{
588	struct Qdisc *root = qdisc_root_sleeping(qdisc);
589
590	ASSERT_RTNL();
591	return &root->running;
592}
593
594static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
595{
596	return qdisc->dev_queue->dev;
597}
598
599static inline void sch_tree_lock(const struct Qdisc *q)
600{
601	spin_lock_bh(qdisc_root_sleeping_lock(q));
602}
603
604static inline void sch_tree_unlock(const struct Qdisc *q)
605{
606	spin_unlock_bh(qdisc_root_sleeping_lock(q));
607}
608
609extern struct Qdisc noop_qdisc;
610extern struct Qdisc_ops noop_qdisc_ops;
611extern struct Qdisc_ops pfifo_fast_ops;
612extern struct Qdisc_ops mq_qdisc_ops;
613extern struct Qdisc_ops noqueue_qdisc_ops;
614extern const struct Qdisc_ops *default_qdisc_ops;
615static inline const struct Qdisc_ops *
616get_default_qdisc_ops(const struct net_device *dev, int ntx)
617{
618	return ntx < dev->real_num_tx_queues ?
619			default_qdisc_ops : &pfifo_fast_ops;
620}
621
622struct Qdisc_class_common {
623	u32			classid;
624	struct hlist_node	hnode;
625};
626
627struct Qdisc_class_hash {
628	struct hlist_head	*hash;
629	unsigned int		hashsize;
630	unsigned int		hashmask;
631	unsigned int		hashelems;
632};
633
634static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
635{
636	id ^= id >> 8;
637	id ^= id >> 4;
638	return id & mask;
639}
640
641static inline struct Qdisc_class_common *
642qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
643{
644	struct Qdisc_class_common *cl;
645	unsigned int h;
646
647	if (!id)
648		return NULL;
649
650	h = qdisc_class_hash(id, hash->hashmask);
651	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
652		if (cl->classid == id)
653			return cl;
654	}
655	return NULL;
656}
657
658static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
659{
660	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
661
662	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
663}
664
665int qdisc_class_hash_init(struct Qdisc_class_hash *);
666void qdisc_class_hash_insert(struct Qdisc_class_hash *,
667			     struct Qdisc_class_common *);
668void qdisc_class_hash_remove(struct Qdisc_class_hash *,
669			     struct Qdisc_class_common *);
670void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
671void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
672
673int dev_qdisc_change_tx_queue_len(struct net_device *dev);
674void dev_qdisc_change_real_num_tx(struct net_device *dev,
675				  unsigned int new_real_tx);
676void dev_init_scheduler(struct net_device *dev);
677void dev_shutdown(struct net_device *dev);
678void dev_activate(struct net_device *dev);
679void dev_deactivate(struct net_device *dev);
680void dev_deactivate_many(struct list_head *head);
681struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
682			      struct Qdisc *qdisc);
683void qdisc_reset(struct Qdisc *qdisc);
684void qdisc_put(struct Qdisc *qdisc);
685void qdisc_put_unlocked(struct Qdisc *qdisc);
686void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
687#ifdef CONFIG_NET_SCHED
688int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
689			      void *type_data);
690void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
691				struct Qdisc *new, struct Qdisc *old,
692				enum tc_setup_type type, void *type_data,
693				struct netlink_ext_ack *extack);
694#else
695static inline int
696qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
697			  void *type_data)
698{
699	q->flags &= ~TCQ_F_OFFLOADED;
700	return 0;
701}
702
703static inline void
704qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
705			   struct Qdisc *new, struct Qdisc *old,
706			   enum tc_setup_type type, void *type_data,
707			   struct netlink_ext_ack *extack)
708{
709}
710#endif
711struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
712			  const struct Qdisc_ops *ops,
713			  struct netlink_ext_ack *extack);
714void qdisc_free(struct Qdisc *qdisc);
715struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
716				const struct Qdisc_ops *ops, u32 parentid,
717				struct netlink_ext_ack *extack);
718void __qdisc_calculate_pkt_len(struct sk_buff *skb,
719			       const struct qdisc_size_table *stab);
720int skb_do_redirect(struct sk_buff *);
721
722static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
723{
724#ifdef CONFIG_NET_CLS_ACT
725	return skb->tc_at_ingress;
726#else
727	return false;
728#endif
729}
730
731static inline bool skb_skip_tc_classify(struct sk_buff *skb)
732{
733#ifdef CONFIG_NET_CLS_ACT
734	if (skb->tc_skip_classify) {
735		skb->tc_skip_classify = 0;
736		return true;
737	}
738#endif
739	return false;
740}
741
742/* Reset all TX qdiscs greater than index of a device.  */
743static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
744{
745	struct Qdisc *qdisc;
746
747	for (; i < dev->num_tx_queues; i++) {
748		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
749		if (qdisc) {
750			spin_lock_bh(qdisc_lock(qdisc));
751			qdisc_reset(qdisc);
752			spin_unlock_bh(qdisc_lock(qdisc));
753		}
754	}
755}
756
757/* Are all TX queues of the device empty?  */
758static inline bool qdisc_all_tx_empty(const struct net_device *dev)
759{
760	unsigned int i;
761
762	rcu_read_lock();
763	for (i = 0; i < dev->num_tx_queues; i++) {
764		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
765		const struct Qdisc *q = rcu_dereference(txq->qdisc);
766
767		if (!qdisc_is_empty(q)) {
768			rcu_read_unlock();
769			return false;
770		}
771	}
772	rcu_read_unlock();
773	return true;
774}
775
776/* Are any of the TX qdiscs changing?  */
777static inline bool qdisc_tx_changing(const struct net_device *dev)
778{
779	unsigned int i;
780
781	for (i = 0; i < dev->num_tx_queues; i++) {
782		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
783		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
784			return true;
785	}
786	return false;
787}
788
789/* Is the device using the noop qdisc on all queues?  */
790static inline bool qdisc_tx_is_noop(const struct net_device *dev)
791{
792	unsigned int i;
793
794	for (i = 0; i < dev->num_tx_queues; i++) {
795		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
796		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
797			return false;
798	}
799	return true;
800}
801
802static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
803{
804	return qdisc_skb_cb(skb)->pkt_len;
805}
806
807/* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
808enum net_xmit_qdisc_t {
809	__NET_XMIT_STOLEN = 0x00010000,
810	__NET_XMIT_BYPASS = 0x00020000,
811};
812
813#ifdef CONFIG_NET_CLS_ACT
814#define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
815#else
816#define net_xmit_drop_count(e)	(1)
817#endif
818
819static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
820					   const struct Qdisc *sch)
821{
822#ifdef CONFIG_NET_SCHED
823	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
824
825	if (stab)
826		__qdisc_calculate_pkt_len(skb, stab);
827#endif
828}
829
830static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
831				struct sk_buff **to_free)
832{
833	qdisc_calculate_pkt_len(skb, sch);
834	return sch->enqueue(skb, sch, to_free);
835}
836
837static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
838				  __u64 bytes, __u32 packets)
839{
840	bstats->bytes += bytes;
841	bstats->packets += packets;
842}
843
844static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
845				 const struct sk_buff *skb)
846{
847	_bstats_update(bstats,
848		       qdisc_pkt_len(skb),
849		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
850}
851
852static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
853				      __u64 bytes, __u32 packets)
854{
855	u64_stats_update_begin(&bstats->syncp);
856	_bstats_update(&bstats->bstats, bytes, packets);
857	u64_stats_update_end(&bstats->syncp);
858}
859
860static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
861				     const struct sk_buff *skb)
862{
863	u64_stats_update_begin(&bstats->syncp);
864	bstats_update(&bstats->bstats, skb);
865	u64_stats_update_end(&bstats->syncp);
866}
867
868static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
869					   const struct sk_buff *skb)
870{
871	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
872}
873
874static inline void qdisc_bstats_update(struct Qdisc *sch,
875				       const struct sk_buff *skb)
876{
877	bstats_update(&sch->bstats, skb);
878}
879
880static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
881					    const struct sk_buff *skb)
882{
883	sch->qstats.backlog -= qdisc_pkt_len(skb);
884}
885
886static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
887						const struct sk_buff *skb)
888{
889	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
890}
891
892static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
893					    const struct sk_buff *skb)
894{
895	sch->qstats.backlog += qdisc_pkt_len(skb);
896}
897
898static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
899						const struct sk_buff *skb)
900{
901	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
902}
903
904static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
905{
906	this_cpu_inc(sch->cpu_qstats->qlen);
907}
908
909static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
910{
911	this_cpu_dec(sch->cpu_qstats->qlen);
912}
913
914static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
915{
916	this_cpu_inc(sch->cpu_qstats->requeues);
917}
918
919static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
920{
921	sch->qstats.drops += count;
922}
923
924static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
925{
926	qstats->drops++;
927}
928
929static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
930{
931	qstats->overlimits++;
932}
933
934static inline void qdisc_qstats_drop(struct Qdisc *sch)
935{
936	qstats_drop_inc(&sch->qstats);
937}
938
939static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
940{
941	this_cpu_inc(sch->cpu_qstats->drops);
942}
943
944static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
945{
946	sch->qstats.overlimits++;
947}
948
949static inline int qdisc_qstats_copy(struct gnet_dump *d, struct Qdisc *sch)
950{
951	__u32 qlen = qdisc_qlen_sum(sch);
952
953	return gnet_stats_copy_queue(d, sch->cpu_qstats, &sch->qstats, qlen);
954}
955
956static inline void qdisc_qstats_qlen_backlog(struct Qdisc *sch,  __u32 *qlen,
957					     __u32 *backlog)
958{
959	struct gnet_stats_queue qstats = { 0 };
960	__u32 len = qdisc_qlen_sum(sch);
961
962	__gnet_stats_copy_queue(&qstats, sch->cpu_qstats, &sch->qstats, len);
963	*qlen = qstats.qlen;
964	*backlog = qstats.backlog;
965}
966
967static inline void qdisc_tree_flush_backlog(struct Qdisc *sch)
968{
969	__u32 qlen, backlog;
970
971	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
972	qdisc_tree_reduce_backlog(sch, qlen, backlog);
973}
974
975static inline void qdisc_purge_queue(struct Qdisc *sch)
976{
977	__u32 qlen, backlog;
978
979	qdisc_qstats_qlen_backlog(sch, &qlen, &backlog);
980	qdisc_reset(sch);
981	qdisc_tree_reduce_backlog(sch, qlen, backlog);
982}
983
984static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
985{
986	qh->head = NULL;
987	qh->tail = NULL;
988	qh->qlen = 0;
989}
990
991static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
992					struct qdisc_skb_head *qh)
993{
994	struct sk_buff *last = qh->tail;
995
996	if (last) {
997		skb->next = NULL;
998		last->next = skb;
999		qh->tail = skb;
1000	} else {
1001		qh->tail = skb;
1002		qh->head = skb;
1003	}
1004	qh->qlen++;
1005}
1006
1007static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
1008{
1009	__qdisc_enqueue_tail(skb, &sch->q);
1010	qdisc_qstats_backlog_inc(sch, skb);
1011	return NET_XMIT_SUCCESS;
1012}
1013
1014static inline void __qdisc_enqueue_head(struct sk_buff *skb,
1015					struct qdisc_skb_head *qh)
1016{
1017	skb->next = qh->head;
1018
1019	if (!qh->head)
1020		qh->tail = skb;
1021	qh->head = skb;
1022	qh->qlen++;
1023}
1024
1025static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
1026{
1027	struct sk_buff *skb = qh->head;
1028
1029	if (likely(skb != NULL)) {
1030		qh->head = skb->next;
1031		qh->qlen--;
1032		if (qh->head == NULL)
1033			qh->tail = NULL;
1034		skb->next = NULL;
1035	}
1036
1037	return skb;
1038}
1039
1040static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
1041{
1042	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
1043
1044	if (likely(skb != NULL)) {
1045		qdisc_qstats_backlog_dec(sch, skb);
1046		qdisc_bstats_update(sch, skb);
1047	}
1048
1049	return skb;
1050}
1051
1052/* Instead of calling kfree_skb() while root qdisc lock is held,
1053 * queue the skb for future freeing at end of __dev_xmit_skb()
1054 */
1055static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
1056{
1057	skb->next = *to_free;
1058	*to_free = skb;
1059}
1060
1061static inline void __qdisc_drop_all(struct sk_buff *skb,
1062				    struct sk_buff **to_free)
1063{
1064	if (skb->prev)
1065		skb->prev->next = *to_free;
1066	else
1067		skb->next = *to_free;
1068	*to_free = skb;
1069}
1070
1071static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1072						   struct qdisc_skb_head *qh,
1073						   struct sk_buff **to_free)
1074{
1075	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1076
1077	if (likely(skb != NULL)) {
1078		unsigned int len = qdisc_pkt_len(skb);
1079
1080		qdisc_qstats_backlog_dec(sch, skb);
1081		__qdisc_drop(skb, to_free);
1082		return len;
1083	}
1084
1085	return 0;
1086}
1087
1088static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1089{
1090	const struct qdisc_skb_head *qh = &sch->q;
1091
1092	return qh->head;
1093}
1094
1095/* generic pseudo peek method for non-work-conserving qdisc */
1096static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1097{
1098	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1099
1100	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1101	if (!skb) {
1102		skb = sch->dequeue(sch);
1103
1104		if (skb) {
1105			__skb_queue_head(&sch->gso_skb, skb);
1106			/* it's still part of the queue */
1107			qdisc_qstats_backlog_inc(sch, skb);
1108			sch->q.qlen++;
1109		}
1110	}
1111
1112	return skb;
1113}
1114
1115static inline void qdisc_update_stats_at_dequeue(struct Qdisc *sch,
1116						 struct sk_buff *skb)
1117{
1118	if (qdisc_is_percpu_stats(sch)) {
1119		qdisc_qstats_cpu_backlog_dec(sch, skb);
1120		qdisc_bstats_cpu_update(sch, skb);
1121		qdisc_qstats_cpu_qlen_dec(sch);
1122	} else {
1123		qdisc_qstats_backlog_dec(sch, skb);
1124		qdisc_bstats_update(sch, skb);
1125		sch->q.qlen--;
1126	}
1127}
1128
1129static inline void qdisc_update_stats_at_enqueue(struct Qdisc *sch,
1130						 unsigned int pkt_len)
1131{
1132	if (qdisc_is_percpu_stats(sch)) {
1133		qdisc_qstats_cpu_qlen_inc(sch);
1134		this_cpu_add(sch->cpu_qstats->backlog, pkt_len);
1135	} else {
1136		sch->qstats.backlog += pkt_len;
1137		sch->q.qlen++;
1138	}
1139}
1140
1141/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1142static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1143{
1144	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1145
1146	if (skb) {
1147		skb = __skb_dequeue(&sch->gso_skb);
1148		if (qdisc_is_percpu_stats(sch)) {
1149			qdisc_qstats_cpu_backlog_dec(sch, skb);
1150			qdisc_qstats_cpu_qlen_dec(sch);
1151		} else {
1152			qdisc_qstats_backlog_dec(sch, skb);
1153			sch->q.qlen--;
1154		}
1155	} else {
1156		skb = sch->dequeue(sch);
1157	}
1158
1159	return skb;
1160}
1161
1162static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1163{
1164	/*
1165	 * We do not know the backlog in bytes of this list, it
1166	 * is up to the caller to correct it
1167	 */
1168	ASSERT_RTNL();
1169	if (qh->qlen) {
1170		rtnl_kfree_skbs(qh->head, qh->tail);
1171
1172		qh->head = NULL;
1173		qh->tail = NULL;
1174		qh->qlen = 0;
1175	}
1176}
1177
1178static inline void qdisc_reset_queue(struct Qdisc *sch)
1179{
1180	__qdisc_reset_queue(&sch->q);
1181}
1182
1183static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1184					  struct Qdisc **pold)
1185{
1186	struct Qdisc *old;
1187
1188	sch_tree_lock(sch);
1189	old = *pold;
1190	*pold = new;
1191	if (old != NULL)
1192		qdisc_purge_queue(old);
1193	sch_tree_unlock(sch);
1194
1195	return old;
1196}
1197
1198static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1199{
1200	rtnl_kfree_skbs(skb, skb);
1201	qdisc_qstats_drop(sch);
1202}
1203
1204static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1205				 struct sk_buff **to_free)
1206{
1207	__qdisc_drop(skb, to_free);
1208	qdisc_qstats_cpu_drop(sch);
1209
1210	return NET_XMIT_DROP;
1211}
1212
1213static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1214			     struct sk_buff **to_free)
1215{
1216	__qdisc_drop(skb, to_free);
1217	qdisc_qstats_drop(sch);
1218
1219	return NET_XMIT_DROP;
1220}
1221
1222static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1223				 struct sk_buff **to_free)
1224{
1225	__qdisc_drop_all(skb, to_free);
1226	qdisc_qstats_drop(sch);
1227
1228	return NET_XMIT_DROP;
1229}
1230
1231/* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1232   long it will take to send a packet given its size.
1233 */
1234static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1235{
1236	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1237	if (slot < 0)
1238		slot = 0;
1239	slot >>= rtab->rate.cell_log;
1240	if (slot > 255)
1241		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1242	return rtab->data[slot];
1243}
1244
1245struct psched_ratecfg {
1246	u64	rate_bytes_ps; /* bytes per second */
1247	u32	mult;
1248	u16	overhead;
1249	u16	mpu;
1250	u8	linklayer;
1251	u8	shift;
1252};
1253
1254static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1255				unsigned int len)
1256{
1257	len += r->overhead;
1258
1259	if (len < r->mpu)
1260		len = r->mpu;
1261
1262	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1263		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1264
1265	return ((u64)len * r->mult) >> r->shift;
1266}
1267
1268void psched_ratecfg_precompute(struct psched_ratecfg *r,
1269			       const struct tc_ratespec *conf,
1270			       u64 rate64);
1271
1272static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1273					  const struct psched_ratecfg *r)
1274{
1275	memset(res, 0, sizeof(*res));
1276
1277	/* legacy struct tc_ratespec has a 32bit @rate field
1278	 * Qdisc using 64bit rate should add new attributes
1279	 * in order to maintain compatibility.
1280	 */
1281	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1282
1283	res->overhead = r->overhead;
1284	res->mpu = r->mpu;
1285	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1286}
1287
1288/* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1289 * The fast path only needs to access filter list and to update stats
1290 */
1291struct mini_Qdisc {
1292	struct tcf_proto *filter_list;
1293	struct tcf_block *block;
1294	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1295	struct gnet_stats_queue	__percpu *cpu_qstats;
1296	struct rcu_head rcu;
1297};
1298
1299static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1300						const struct sk_buff *skb)
1301{
1302	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1303}
1304
1305static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1306{
1307	this_cpu_inc(miniq->cpu_qstats->drops);
1308}
1309
1310struct mini_Qdisc_pair {
1311	struct mini_Qdisc miniq1;
1312	struct mini_Qdisc miniq2;
1313	struct mini_Qdisc __rcu **p_miniq;
1314};
1315
1316void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1317			  struct tcf_proto *tp_head);
1318void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1319			  struct mini_Qdisc __rcu **p_miniq);
1320void mini_qdisc_pair_block_init(struct mini_Qdisc_pair *miniqp,
1321				struct tcf_block *block);
1322
1323/* Make sure qdisc is no longer in SCHED state. */
1324static inline void qdisc_synchronize(const struct Qdisc *q)
1325{
1326	while (test_bit(__QDISC_STATE_SCHED, &q->state))
1327		msleep(1);
1328}
1329
1330#endif
1331