xref: /openbmc/linux/include/net/sch_generic.h (revision dfd4f649)
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 <net/gen_stats.h>
17 #include <net/rtnetlink.h>
18 
19 struct Qdisc_ops;
20 struct qdisc_walker;
21 struct tcf_walker;
22 struct module;
23 struct bpf_flow_keys;
24 
25 typedef int tc_setup_cb_t(enum tc_setup_type type,
26 			  void *type_data, void *cb_priv);
27 
28 typedef int tc_indr_block_bind_cb_t(struct net_device *dev, void *cb_priv,
29 				    enum tc_setup_type type, void *type_data);
30 
31 struct qdisc_rate_table {
32 	struct tc_ratespec rate;
33 	u32		data[256];
34 	struct qdisc_rate_table *next;
35 	int		refcnt;
36 };
37 
38 enum qdisc_state_t {
39 	__QDISC_STATE_SCHED,
40 	__QDISC_STATE_DEACTIVATED,
41 };
42 
43 struct qdisc_size_table {
44 	struct rcu_head		rcu;
45 	struct list_head	list;
46 	struct tc_sizespec	szopts;
47 	int			refcnt;
48 	u16			data[];
49 };
50 
51 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
52 struct qdisc_skb_head {
53 	struct sk_buff	*head;
54 	struct sk_buff	*tail;
55 	union {
56 		u32		qlen;
57 		atomic_t	atomic_qlen;
58 	};
59 	spinlock_t	lock;
60 };
61 
62 struct Qdisc {
63 	int 			(*enqueue)(struct sk_buff *skb,
64 					   struct Qdisc *sch,
65 					   struct sk_buff **to_free);
66 	struct sk_buff *	(*dequeue)(struct Qdisc *sch);
67 	unsigned int		flags;
68 #define TCQ_F_BUILTIN		1
69 #define TCQ_F_INGRESS		2
70 #define TCQ_F_CAN_BYPASS	4
71 #define TCQ_F_MQROOT		8
72 #define TCQ_F_ONETXQUEUE	0x10 /* dequeue_skb() can assume all skbs are for
73 				      * q->dev_queue : It can test
74 				      * netif_xmit_frozen_or_stopped() before
75 				      * dequeueing next packet.
76 				      * Its true for MQ/MQPRIO slaves, or non
77 				      * multiqueue device.
78 				      */
79 #define TCQ_F_WARN_NONWC	(1 << 16)
80 #define TCQ_F_CPUSTATS		0x20 /* run using percpu statistics */
81 #define TCQ_F_NOPARENT		0x40 /* root of its hierarchy :
82 				      * qdisc_tree_decrease_qlen() should stop.
83 				      */
84 #define TCQ_F_INVISIBLE		0x80 /* invisible by default in dump */
85 #define TCQ_F_NOLOCK		0x100 /* qdisc does not require locking */
86 #define TCQ_F_OFFLOADED		0x200 /* qdisc is offloaded to HW */
87 	u32			limit;
88 	const struct Qdisc_ops	*ops;
89 	struct qdisc_size_table	__rcu *stab;
90 	struct hlist_node       hash;
91 	u32			handle;
92 	u32			parent;
93 
94 	struct netdev_queue	*dev_queue;
95 
96 	struct net_rate_estimator __rcu *rate_est;
97 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
98 	struct gnet_stats_queue	__percpu *cpu_qstats;
99 	int			padded;
100 	refcount_t		refcnt;
101 
102 	/*
103 	 * For performance sake on SMP, we put highly modified fields at the end
104 	 */
105 	struct sk_buff_head	gso_skb ____cacheline_aligned_in_smp;
106 	struct qdisc_skb_head	q;
107 	struct gnet_stats_basic_packed bstats;
108 	seqcount_t		running;
109 	struct gnet_stats_queue	qstats;
110 	unsigned long		state;
111 	struct Qdisc            *next_sched;
112 	struct sk_buff_head	skb_bad_txq;
113 
114 	spinlock_t		busylock ____cacheline_aligned_in_smp;
115 	spinlock_t		seqlock;
116 	struct rcu_head		rcu;
117 };
118 
119 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
120 {
121 	if (qdisc->flags & TCQ_F_BUILTIN)
122 		return;
123 	refcount_inc(&qdisc->refcnt);
124 }
125 
126 /* Intended to be used by unlocked users, when concurrent qdisc release is
127  * possible.
128  */
129 
130 static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
131 {
132 	if (qdisc->flags & TCQ_F_BUILTIN)
133 		return qdisc;
134 	if (refcount_inc_not_zero(&qdisc->refcnt))
135 		return qdisc;
136 	return NULL;
137 }
138 
139 static inline bool qdisc_is_running(struct Qdisc *qdisc)
140 {
141 	if (qdisc->flags & TCQ_F_NOLOCK)
142 		return spin_is_locked(&qdisc->seqlock);
143 	return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
144 }
145 
146 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
147 {
148 	if (qdisc->flags & TCQ_F_NOLOCK) {
149 		if (!spin_trylock(&qdisc->seqlock))
150 			return false;
151 	} else if (qdisc_is_running(qdisc)) {
152 		return false;
153 	}
154 	/* Variant of write_seqcount_begin() telling lockdep a trylock
155 	 * was attempted.
156 	 */
157 	raw_write_seqcount_begin(&qdisc->running);
158 	seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
159 	return true;
160 }
161 
162 static inline void qdisc_run_end(struct Qdisc *qdisc)
163 {
164 	write_seqcount_end(&qdisc->running);
165 	if (qdisc->flags & TCQ_F_NOLOCK)
166 		spin_unlock(&qdisc->seqlock);
167 }
168 
169 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
170 {
171 	return qdisc->flags & TCQ_F_ONETXQUEUE;
172 }
173 
174 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
175 {
176 #ifdef CONFIG_BQL
177 	/* Non-BQL migrated drivers will return 0, too. */
178 	return dql_avail(&txq->dql);
179 #else
180 	return 0;
181 #endif
182 }
183 
184 struct Qdisc_class_ops {
185 	unsigned int		flags;
186 	/* Child qdisc manipulation */
187 	struct netdev_queue *	(*select_queue)(struct Qdisc *, struct tcmsg *);
188 	int			(*graft)(struct Qdisc *, unsigned long cl,
189 					struct Qdisc *, struct Qdisc **,
190 					struct netlink_ext_ack *extack);
191 	struct Qdisc *		(*leaf)(struct Qdisc *, unsigned long cl);
192 	void			(*qlen_notify)(struct Qdisc *, unsigned long);
193 
194 	/* Class manipulation routines */
195 	unsigned long		(*find)(struct Qdisc *, u32 classid);
196 	int			(*change)(struct Qdisc *, u32, u32,
197 					struct nlattr **, unsigned long *,
198 					struct netlink_ext_ack *);
199 	int			(*delete)(struct Qdisc *, unsigned long);
200 	void			(*walk)(struct Qdisc *, struct qdisc_walker * arg);
201 
202 	/* Filter manipulation */
203 	struct tcf_block *	(*tcf_block)(struct Qdisc *sch,
204 					     unsigned long arg,
205 					     struct netlink_ext_ack *extack);
206 	unsigned long		(*bind_tcf)(struct Qdisc *, unsigned long,
207 					u32 classid);
208 	void			(*unbind_tcf)(struct Qdisc *, unsigned long);
209 
210 	/* rtnetlink specific */
211 	int			(*dump)(struct Qdisc *, unsigned long,
212 					struct sk_buff *skb, struct tcmsg*);
213 	int			(*dump_stats)(struct Qdisc *, unsigned long,
214 					struct gnet_dump *);
215 };
216 
217 /* Qdisc_class_ops flag values */
218 
219 /* Implements API that doesn't require rtnl lock */
220 enum qdisc_class_ops_flags {
221 	QDISC_CLASS_OPS_DOIT_UNLOCKED = 1,
222 };
223 
224 struct Qdisc_ops {
225 	struct Qdisc_ops	*next;
226 	const struct Qdisc_class_ops	*cl_ops;
227 	char			id[IFNAMSIZ];
228 	int			priv_size;
229 	unsigned int		static_flags;
230 
231 	int 			(*enqueue)(struct sk_buff *skb,
232 					   struct Qdisc *sch,
233 					   struct sk_buff **to_free);
234 	struct sk_buff *	(*dequeue)(struct Qdisc *);
235 	struct sk_buff *	(*peek)(struct Qdisc *);
236 
237 	int			(*init)(struct Qdisc *sch, struct nlattr *arg,
238 					struct netlink_ext_ack *extack);
239 	void			(*reset)(struct Qdisc *);
240 	void			(*destroy)(struct Qdisc *);
241 	int			(*change)(struct Qdisc *sch,
242 					  struct nlattr *arg,
243 					  struct netlink_ext_ack *extack);
244 	void			(*attach)(struct Qdisc *sch);
245 	int			(*change_tx_queue_len)(struct Qdisc *, unsigned int);
246 
247 	int			(*dump)(struct Qdisc *, struct sk_buff *);
248 	int			(*dump_stats)(struct Qdisc *, struct gnet_dump *);
249 
250 	void			(*ingress_block_set)(struct Qdisc *sch,
251 						     u32 block_index);
252 	void			(*egress_block_set)(struct Qdisc *sch,
253 						    u32 block_index);
254 	u32			(*ingress_block_get)(struct Qdisc *sch);
255 	u32			(*egress_block_get)(struct Qdisc *sch);
256 
257 	struct module		*owner;
258 };
259 
260 
261 struct tcf_result {
262 	union {
263 		struct {
264 			unsigned long	class;
265 			u32		classid;
266 		};
267 		const struct tcf_proto *goto_tp;
268 
269 		/* used by the TC_ACT_REINSERT action */
270 		struct {
271 			bool		ingress;
272 			struct gnet_stats_queue *qstats;
273 		};
274 	};
275 };
276 
277 struct tcf_chain;
278 
279 struct tcf_proto_ops {
280 	struct list_head	head;
281 	char			kind[IFNAMSIZ];
282 
283 	int			(*classify)(struct sk_buff *,
284 					    const struct tcf_proto *,
285 					    struct tcf_result *);
286 	int			(*init)(struct tcf_proto*);
287 	void			(*destroy)(struct tcf_proto *tp, bool rtnl_held,
288 					   struct netlink_ext_ack *extack);
289 
290 	void*			(*get)(struct tcf_proto*, u32 handle);
291 	void			(*put)(struct tcf_proto *tp, void *f);
292 	int			(*change)(struct net *net, struct sk_buff *,
293 					struct tcf_proto*, unsigned long,
294 					u32 handle, struct nlattr **,
295 					void **, bool, bool,
296 					struct netlink_ext_ack *);
297 	int			(*delete)(struct tcf_proto *tp, void *arg,
298 					  bool *last, bool rtnl_held,
299 					  struct netlink_ext_ack *);
300 	void			(*walk)(struct tcf_proto *tp,
301 					struct tcf_walker *arg, bool rtnl_held);
302 	int			(*reoffload)(struct tcf_proto *tp, bool add,
303 					     tc_setup_cb_t *cb, void *cb_priv,
304 					     struct netlink_ext_ack *extack);
305 	void			(*bind_class)(void *, u32, unsigned long);
306 	void *			(*tmplt_create)(struct net *net,
307 						struct tcf_chain *chain,
308 						struct nlattr **tca,
309 						struct netlink_ext_ack *extack);
310 	void			(*tmplt_destroy)(void *tmplt_priv);
311 
312 	/* rtnetlink specific */
313 	int			(*dump)(struct net*, struct tcf_proto*, void *,
314 					struct sk_buff *skb, struct tcmsg*,
315 					bool);
316 	int			(*tmplt_dump)(struct sk_buff *skb,
317 					      struct net *net,
318 					      void *tmplt_priv);
319 
320 	struct module		*owner;
321 	int			flags;
322 };
323 
324 enum tcf_proto_ops_flags {
325 	TCF_PROTO_OPS_DOIT_UNLOCKED = 1,
326 };
327 
328 struct tcf_proto {
329 	/* Fast access part */
330 	struct tcf_proto __rcu	*next;
331 	void __rcu		*root;
332 
333 	/* called under RCU BH lock*/
334 	int			(*classify)(struct sk_buff *,
335 					    const struct tcf_proto *,
336 					    struct tcf_result *);
337 	__be16			protocol;
338 
339 	/* All the rest */
340 	u32			prio;
341 	void			*data;
342 	const struct tcf_proto_ops	*ops;
343 	struct tcf_chain	*chain;
344 	/* Lock protects tcf_proto shared state and can be used by unlocked
345 	 * classifiers to protect their private data.
346 	 */
347 	spinlock_t		lock;
348 	bool			deleting;
349 	refcount_t		refcnt;
350 	struct rcu_head		rcu;
351 };
352 
353 struct qdisc_skb_cb {
354 	union {
355 		struct {
356 			unsigned int		pkt_len;
357 			u16			slave_dev_queue_mapping;
358 			u16			tc_classid;
359 		};
360 		struct bpf_flow_keys *flow_keys;
361 	};
362 #define QDISC_CB_PRIV_LEN 20
363 	unsigned char		data[QDISC_CB_PRIV_LEN];
364 };
365 
366 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
367 
368 struct tcf_chain {
369 	/* Protects filter_chain. */
370 	struct mutex filter_chain_lock;
371 	struct tcf_proto __rcu *filter_chain;
372 	struct list_head list;
373 	struct tcf_block *block;
374 	u32 index; /* chain index */
375 	unsigned int refcnt;
376 	unsigned int action_refcnt;
377 	bool explicitly_created;
378 	bool flushing;
379 	const struct tcf_proto_ops *tmplt_ops;
380 	void *tmplt_priv;
381 	struct rcu_head rcu;
382 };
383 
384 struct tcf_block {
385 	/* Lock protects tcf_block and lifetime-management data of chains
386 	 * attached to the block (refcnt, action_refcnt, explicitly_created).
387 	 */
388 	struct mutex lock;
389 	struct list_head chain_list;
390 	u32 index; /* block index for shared blocks */
391 	refcount_t refcnt;
392 	struct net *net;
393 	struct Qdisc *q;
394 	struct list_head cb_list;
395 	struct list_head owner_list;
396 	bool keep_dst;
397 	unsigned int offloadcnt; /* Number of oddloaded filters */
398 	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */
399 	struct {
400 		struct tcf_chain *chain;
401 		struct list_head filter_chain_list;
402 	} chain0;
403 	struct rcu_head rcu;
404 };
405 
406 #ifdef CONFIG_PROVE_LOCKING
407 static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
408 {
409 	return lockdep_is_held(&chain->filter_chain_lock);
410 }
411 
412 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
413 {
414 	return lockdep_is_held(&tp->lock);
415 }
416 #else
417 static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
418 {
419 	return true;
420 }
421 
422 static inline bool lockdep_tcf_proto_is_locked(struct tcf_proto *tp)
423 {
424 	return true;
425 }
426 #endif /* #ifdef CONFIG_PROVE_LOCKING */
427 
428 #define tcf_chain_dereference(p, chain)					\
429 	rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
430 
431 #define tcf_proto_dereference(p, tp)					\
432 	rcu_dereference_protected(p, lockdep_tcf_proto_is_locked(tp))
433 
434 static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
435 {
436 	if (*flags & TCA_CLS_FLAGS_IN_HW)
437 		return;
438 	*flags |= TCA_CLS_FLAGS_IN_HW;
439 	block->offloadcnt++;
440 }
441 
442 static inline void tcf_block_offload_dec(struct tcf_block *block, u32 *flags)
443 {
444 	if (!(*flags & TCA_CLS_FLAGS_IN_HW))
445 		return;
446 	*flags &= ~TCA_CLS_FLAGS_IN_HW;
447 	block->offloadcnt--;
448 }
449 
450 static inline void
451 tc_cls_offload_cnt_update(struct tcf_block *block, u32 *cnt,
452 			  u32 *flags, bool add)
453 {
454 	if (add) {
455 		if (!*cnt)
456 			tcf_block_offload_inc(block, flags);
457 		(*cnt)++;
458 	} else {
459 		(*cnt)--;
460 		if (!*cnt)
461 			tcf_block_offload_dec(block, flags);
462 	}
463 }
464 
465 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
466 {
467 	struct qdisc_skb_cb *qcb;
468 
469 	BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
470 	BUILD_BUG_ON(sizeof(qcb->data) < sz);
471 }
472 
473 static inline int qdisc_qlen(const struct Qdisc *q)
474 {
475 	return q->q.qlen;
476 }
477 
478 static inline u32 qdisc_qlen_sum(const struct Qdisc *q)
479 {
480 	u32 qlen = q->qstats.qlen;
481 
482 	if (q->flags & TCQ_F_NOLOCK)
483 		qlen += atomic_read(&q->q.atomic_qlen);
484 	else
485 		qlen += q->q.qlen;
486 
487 	return qlen;
488 }
489 
490 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
491 {
492 	return (struct qdisc_skb_cb *)skb->cb;
493 }
494 
495 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
496 {
497 	return &qdisc->q.lock;
498 }
499 
500 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
501 {
502 	struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
503 
504 	return q;
505 }
506 
507 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
508 {
509 	return qdisc->dev_queue->qdisc_sleeping;
510 }
511 
512 /* The qdisc root lock is a mechanism by which to top level
513  * of a qdisc tree can be locked from any qdisc node in the
514  * forest.  This allows changing the configuration of some
515  * aspect of the qdisc tree while blocking out asynchronous
516  * qdisc access in the packet processing paths.
517  *
518  * It is only legal to do this when the root will not change
519  * on us.  Otherwise we'll potentially lock the wrong qdisc
520  * root.  This is enforced by holding the RTNL semaphore, which
521  * all users of this lock accessor must do.
522  */
523 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
524 {
525 	struct Qdisc *root = qdisc_root(qdisc);
526 
527 	ASSERT_RTNL();
528 	return qdisc_lock(root);
529 }
530 
531 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
532 {
533 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
534 
535 	ASSERT_RTNL();
536 	return qdisc_lock(root);
537 }
538 
539 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
540 {
541 	struct Qdisc *root = qdisc_root_sleeping(qdisc);
542 
543 	ASSERT_RTNL();
544 	return &root->running;
545 }
546 
547 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
548 {
549 	return qdisc->dev_queue->dev;
550 }
551 
552 static inline void sch_tree_lock(const struct Qdisc *q)
553 {
554 	spin_lock_bh(qdisc_root_sleeping_lock(q));
555 }
556 
557 static inline void sch_tree_unlock(const struct Qdisc *q)
558 {
559 	spin_unlock_bh(qdisc_root_sleeping_lock(q));
560 }
561 
562 extern struct Qdisc noop_qdisc;
563 extern struct Qdisc_ops noop_qdisc_ops;
564 extern struct Qdisc_ops pfifo_fast_ops;
565 extern struct Qdisc_ops mq_qdisc_ops;
566 extern struct Qdisc_ops noqueue_qdisc_ops;
567 extern const struct Qdisc_ops *default_qdisc_ops;
568 static inline const struct Qdisc_ops *
569 get_default_qdisc_ops(const struct net_device *dev, int ntx)
570 {
571 	return ntx < dev->real_num_tx_queues ?
572 			default_qdisc_ops : &pfifo_fast_ops;
573 }
574 
575 struct Qdisc_class_common {
576 	u32			classid;
577 	struct hlist_node	hnode;
578 };
579 
580 struct Qdisc_class_hash {
581 	struct hlist_head	*hash;
582 	unsigned int		hashsize;
583 	unsigned int		hashmask;
584 	unsigned int		hashelems;
585 };
586 
587 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
588 {
589 	id ^= id >> 8;
590 	id ^= id >> 4;
591 	return id & mask;
592 }
593 
594 static inline struct Qdisc_class_common *
595 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
596 {
597 	struct Qdisc_class_common *cl;
598 	unsigned int h;
599 
600 	if (!id)
601 		return NULL;
602 
603 	h = qdisc_class_hash(id, hash->hashmask);
604 	hlist_for_each_entry(cl, &hash->hash[h], hnode) {
605 		if (cl->classid == id)
606 			return cl;
607 	}
608 	return NULL;
609 }
610 
611 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
612 {
613 	u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
614 
615 	return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
616 }
617 
618 int qdisc_class_hash_init(struct Qdisc_class_hash *);
619 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
620 			     struct Qdisc_class_common *);
621 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
622 			     struct Qdisc_class_common *);
623 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
624 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
625 
626 int dev_qdisc_change_tx_queue_len(struct net_device *dev);
627 void dev_init_scheduler(struct net_device *dev);
628 void dev_shutdown(struct net_device *dev);
629 void dev_activate(struct net_device *dev);
630 void dev_deactivate(struct net_device *dev);
631 void dev_deactivate_many(struct list_head *head);
632 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
633 			      struct Qdisc *qdisc);
634 void qdisc_reset(struct Qdisc *qdisc);
635 void qdisc_put(struct Qdisc *qdisc);
636 void qdisc_put_unlocked(struct Qdisc *qdisc);
637 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, int n, int len);
638 #ifdef CONFIG_NET_SCHED
639 int qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
640 			      void *type_data);
641 void qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
642 				struct Qdisc *new, struct Qdisc *old,
643 				enum tc_setup_type type, void *type_data,
644 				struct netlink_ext_ack *extack);
645 #else
646 static inline int
647 qdisc_offload_dump_helper(struct Qdisc *q, enum tc_setup_type type,
648 			  void *type_data)
649 {
650 	q->flags &= ~TCQ_F_OFFLOADED;
651 	return 0;
652 }
653 
654 static inline void
655 qdisc_offload_graft_helper(struct net_device *dev, struct Qdisc *sch,
656 			   struct Qdisc *new, struct Qdisc *old,
657 			   enum tc_setup_type type, void *type_data,
658 			   struct netlink_ext_ack *extack)
659 {
660 }
661 #endif
662 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
663 			  const struct Qdisc_ops *ops,
664 			  struct netlink_ext_ack *extack);
665 void qdisc_free(struct Qdisc *qdisc);
666 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
667 				const struct Qdisc_ops *ops, u32 parentid,
668 				struct netlink_ext_ack *extack);
669 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
670 			       const struct qdisc_size_table *stab);
671 int skb_do_redirect(struct sk_buff *);
672 
673 static inline void skb_reset_tc(struct sk_buff *skb)
674 {
675 #ifdef CONFIG_NET_CLS_ACT
676 	skb->tc_redirected = 0;
677 #endif
678 }
679 
680 static inline bool skb_is_tc_redirected(const struct sk_buff *skb)
681 {
682 #ifdef CONFIG_NET_CLS_ACT
683 	return skb->tc_redirected;
684 #else
685 	return false;
686 #endif
687 }
688 
689 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
690 {
691 #ifdef CONFIG_NET_CLS_ACT
692 	return skb->tc_at_ingress;
693 #else
694 	return false;
695 #endif
696 }
697 
698 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
699 {
700 #ifdef CONFIG_NET_CLS_ACT
701 	if (skb->tc_skip_classify) {
702 		skb->tc_skip_classify = 0;
703 		return true;
704 	}
705 #endif
706 	return false;
707 }
708 
709 /* Reset all TX qdiscs greater than index of a device.  */
710 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
711 {
712 	struct Qdisc *qdisc;
713 
714 	for (; i < dev->num_tx_queues; i++) {
715 		qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
716 		if (qdisc) {
717 			spin_lock_bh(qdisc_lock(qdisc));
718 			qdisc_reset(qdisc);
719 			spin_unlock_bh(qdisc_lock(qdisc));
720 		}
721 	}
722 }
723 
724 static inline void qdisc_reset_all_tx(struct net_device *dev)
725 {
726 	qdisc_reset_all_tx_gt(dev, 0);
727 }
728 
729 /* Are all TX queues of the device empty?  */
730 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
731 {
732 	unsigned int i;
733 
734 	rcu_read_lock();
735 	for (i = 0; i < dev->num_tx_queues; i++) {
736 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
737 		const struct Qdisc *q = rcu_dereference(txq->qdisc);
738 
739 		if (q->q.qlen) {
740 			rcu_read_unlock();
741 			return false;
742 		}
743 	}
744 	rcu_read_unlock();
745 	return true;
746 }
747 
748 /* Are any of the TX qdiscs changing?  */
749 static inline bool qdisc_tx_changing(const struct net_device *dev)
750 {
751 	unsigned int i;
752 
753 	for (i = 0; i < dev->num_tx_queues; i++) {
754 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
755 		if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
756 			return true;
757 	}
758 	return false;
759 }
760 
761 /* Is the device using the noop qdisc on all queues?  */
762 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
763 {
764 	unsigned int i;
765 
766 	for (i = 0; i < dev->num_tx_queues; i++) {
767 		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
768 		if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
769 			return false;
770 	}
771 	return true;
772 }
773 
774 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
775 {
776 	return qdisc_skb_cb(skb)->pkt_len;
777 }
778 
779 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
780 enum net_xmit_qdisc_t {
781 	__NET_XMIT_STOLEN = 0x00010000,
782 	__NET_XMIT_BYPASS = 0x00020000,
783 };
784 
785 #ifdef CONFIG_NET_CLS_ACT
786 #define net_xmit_drop_count(e)	((e) & __NET_XMIT_STOLEN ? 0 : 1)
787 #else
788 #define net_xmit_drop_count(e)	(1)
789 #endif
790 
791 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
792 					   const struct Qdisc *sch)
793 {
794 #ifdef CONFIG_NET_SCHED
795 	struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
796 
797 	if (stab)
798 		__qdisc_calculate_pkt_len(skb, stab);
799 #endif
800 }
801 
802 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
803 				struct sk_buff **to_free)
804 {
805 	qdisc_calculate_pkt_len(skb, sch);
806 	return sch->enqueue(skb, sch, to_free);
807 }
808 
809 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
810 {
811 	return q->flags & TCQ_F_CPUSTATS;
812 }
813 
814 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
815 				  __u64 bytes, __u32 packets)
816 {
817 	bstats->bytes += bytes;
818 	bstats->packets += packets;
819 }
820 
821 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
822 				 const struct sk_buff *skb)
823 {
824 	_bstats_update(bstats,
825 		       qdisc_pkt_len(skb),
826 		       skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
827 }
828 
829 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
830 				      __u64 bytes, __u32 packets)
831 {
832 	u64_stats_update_begin(&bstats->syncp);
833 	_bstats_update(&bstats->bstats, bytes, packets);
834 	u64_stats_update_end(&bstats->syncp);
835 }
836 
837 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
838 				     const struct sk_buff *skb)
839 {
840 	u64_stats_update_begin(&bstats->syncp);
841 	bstats_update(&bstats->bstats, skb);
842 	u64_stats_update_end(&bstats->syncp);
843 }
844 
845 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
846 					   const struct sk_buff *skb)
847 {
848 	bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
849 }
850 
851 static inline void qdisc_bstats_update(struct Qdisc *sch,
852 				       const struct sk_buff *skb)
853 {
854 	bstats_update(&sch->bstats, skb);
855 }
856 
857 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
858 					    const struct sk_buff *skb)
859 {
860 	sch->qstats.backlog -= qdisc_pkt_len(skb);
861 }
862 
863 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
864 						const struct sk_buff *skb)
865 {
866 	this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
867 }
868 
869 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
870 					    const struct sk_buff *skb)
871 {
872 	sch->qstats.backlog += qdisc_pkt_len(skb);
873 }
874 
875 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
876 						const struct sk_buff *skb)
877 {
878 	this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
879 }
880 
881 static inline void qdisc_qstats_atomic_qlen_inc(struct Qdisc *sch)
882 {
883 	atomic_inc(&sch->q.atomic_qlen);
884 }
885 
886 static inline void qdisc_qstats_atomic_qlen_dec(struct Qdisc *sch)
887 {
888 	atomic_dec(&sch->q.atomic_qlen);
889 }
890 
891 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
892 {
893 	this_cpu_inc(sch->cpu_qstats->requeues);
894 }
895 
896 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
897 {
898 	sch->qstats.drops += count;
899 }
900 
901 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
902 {
903 	qstats->drops++;
904 }
905 
906 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
907 {
908 	qstats->overlimits++;
909 }
910 
911 static inline void qdisc_qstats_drop(struct Qdisc *sch)
912 {
913 	qstats_drop_inc(&sch->qstats);
914 }
915 
916 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
917 {
918 	this_cpu_inc(sch->cpu_qstats->drops);
919 }
920 
921 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
922 {
923 	sch->qstats.overlimits++;
924 }
925 
926 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
927 {
928 	qh->head = NULL;
929 	qh->tail = NULL;
930 	qh->qlen = 0;
931 }
932 
933 static inline void __qdisc_enqueue_tail(struct sk_buff *skb,
934 					struct qdisc_skb_head *qh)
935 {
936 	struct sk_buff *last = qh->tail;
937 
938 	if (last) {
939 		skb->next = NULL;
940 		last->next = skb;
941 		qh->tail = skb;
942 	} else {
943 		qh->tail = skb;
944 		qh->head = skb;
945 	}
946 	qh->qlen++;
947 }
948 
949 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
950 {
951 	__qdisc_enqueue_tail(skb, &sch->q);
952 	qdisc_qstats_backlog_inc(sch, skb);
953 	return NET_XMIT_SUCCESS;
954 }
955 
956 static inline void __qdisc_enqueue_head(struct sk_buff *skb,
957 					struct qdisc_skb_head *qh)
958 {
959 	skb->next = qh->head;
960 
961 	if (!qh->head)
962 		qh->tail = skb;
963 	qh->head = skb;
964 	qh->qlen++;
965 }
966 
967 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
968 {
969 	struct sk_buff *skb = qh->head;
970 
971 	if (likely(skb != NULL)) {
972 		qh->head = skb->next;
973 		qh->qlen--;
974 		if (qh->head == NULL)
975 			qh->tail = NULL;
976 		skb->next = NULL;
977 	}
978 
979 	return skb;
980 }
981 
982 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
983 {
984 	struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
985 
986 	if (likely(skb != NULL)) {
987 		qdisc_qstats_backlog_dec(sch, skb);
988 		qdisc_bstats_update(sch, skb);
989 	}
990 
991 	return skb;
992 }
993 
994 /* Instead of calling kfree_skb() while root qdisc lock is held,
995  * queue the skb for future freeing at end of __dev_xmit_skb()
996  */
997 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
998 {
999 	skb->next = *to_free;
1000 	*to_free = skb;
1001 }
1002 
1003 static inline void __qdisc_drop_all(struct sk_buff *skb,
1004 				    struct sk_buff **to_free)
1005 {
1006 	if (skb->prev)
1007 		skb->prev->next = *to_free;
1008 	else
1009 		skb->next = *to_free;
1010 	*to_free = skb;
1011 }
1012 
1013 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
1014 						   struct qdisc_skb_head *qh,
1015 						   struct sk_buff **to_free)
1016 {
1017 	struct sk_buff *skb = __qdisc_dequeue_head(qh);
1018 
1019 	if (likely(skb != NULL)) {
1020 		unsigned int len = qdisc_pkt_len(skb);
1021 
1022 		qdisc_qstats_backlog_dec(sch, skb);
1023 		__qdisc_drop(skb, to_free);
1024 		return len;
1025 	}
1026 
1027 	return 0;
1028 }
1029 
1030 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
1031 						 struct sk_buff **to_free)
1032 {
1033 	return __qdisc_queue_drop_head(sch, &sch->q, to_free);
1034 }
1035 
1036 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
1037 {
1038 	const struct qdisc_skb_head *qh = &sch->q;
1039 
1040 	return qh->head;
1041 }
1042 
1043 /* generic pseudo peek method for non-work-conserving qdisc */
1044 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
1045 {
1046 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1047 
1048 	/* we can reuse ->gso_skb because peek isn't called for root qdiscs */
1049 	if (!skb) {
1050 		skb = sch->dequeue(sch);
1051 
1052 		if (skb) {
1053 			__skb_queue_head(&sch->gso_skb, skb);
1054 			/* it's still part of the queue */
1055 			qdisc_qstats_backlog_inc(sch, skb);
1056 			sch->q.qlen++;
1057 		}
1058 	}
1059 
1060 	return skb;
1061 }
1062 
1063 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
1064 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
1065 {
1066 	struct sk_buff *skb = skb_peek(&sch->gso_skb);
1067 
1068 	if (skb) {
1069 		skb = __skb_dequeue(&sch->gso_skb);
1070 		qdisc_qstats_backlog_dec(sch, skb);
1071 		sch->q.qlen--;
1072 	} else {
1073 		skb = sch->dequeue(sch);
1074 	}
1075 
1076 	return skb;
1077 }
1078 
1079 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
1080 {
1081 	/*
1082 	 * We do not know the backlog in bytes of this list, it
1083 	 * is up to the caller to correct it
1084 	 */
1085 	ASSERT_RTNL();
1086 	if (qh->qlen) {
1087 		rtnl_kfree_skbs(qh->head, qh->tail);
1088 
1089 		qh->head = NULL;
1090 		qh->tail = NULL;
1091 		qh->qlen = 0;
1092 	}
1093 }
1094 
1095 static inline void qdisc_reset_queue(struct Qdisc *sch)
1096 {
1097 	__qdisc_reset_queue(&sch->q);
1098 	sch->qstats.backlog = 0;
1099 }
1100 
1101 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
1102 					  struct Qdisc **pold)
1103 {
1104 	struct Qdisc *old;
1105 
1106 	sch_tree_lock(sch);
1107 	old = *pold;
1108 	*pold = new;
1109 	if (old != NULL) {
1110 		unsigned int qlen = old->q.qlen;
1111 		unsigned int backlog = old->qstats.backlog;
1112 
1113 		qdisc_reset(old);
1114 		qdisc_tree_reduce_backlog(old, qlen, backlog);
1115 	}
1116 	sch_tree_unlock(sch);
1117 
1118 	return old;
1119 }
1120 
1121 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
1122 {
1123 	rtnl_kfree_skbs(skb, skb);
1124 	qdisc_qstats_drop(sch);
1125 }
1126 
1127 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
1128 				 struct sk_buff **to_free)
1129 {
1130 	__qdisc_drop(skb, to_free);
1131 	qdisc_qstats_cpu_drop(sch);
1132 
1133 	return NET_XMIT_DROP;
1134 }
1135 
1136 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
1137 			     struct sk_buff **to_free)
1138 {
1139 	__qdisc_drop(skb, to_free);
1140 	qdisc_qstats_drop(sch);
1141 
1142 	return NET_XMIT_DROP;
1143 }
1144 
1145 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
1146 				 struct sk_buff **to_free)
1147 {
1148 	__qdisc_drop_all(skb, to_free);
1149 	qdisc_qstats_drop(sch);
1150 
1151 	return NET_XMIT_DROP;
1152 }
1153 
1154 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
1155    long it will take to send a packet given its size.
1156  */
1157 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
1158 {
1159 	int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
1160 	if (slot < 0)
1161 		slot = 0;
1162 	slot >>= rtab->rate.cell_log;
1163 	if (slot > 255)
1164 		return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
1165 	return rtab->data[slot];
1166 }
1167 
1168 struct psched_ratecfg {
1169 	u64	rate_bytes_ps; /* bytes per second */
1170 	u32	mult;
1171 	u16	overhead;
1172 	u8	linklayer;
1173 	u8	shift;
1174 };
1175 
1176 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
1177 				unsigned int len)
1178 {
1179 	len += r->overhead;
1180 
1181 	if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
1182 		return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
1183 
1184 	return ((u64)len * r->mult) >> r->shift;
1185 }
1186 
1187 void psched_ratecfg_precompute(struct psched_ratecfg *r,
1188 			       const struct tc_ratespec *conf,
1189 			       u64 rate64);
1190 
1191 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
1192 					  const struct psched_ratecfg *r)
1193 {
1194 	memset(res, 0, sizeof(*res));
1195 
1196 	/* legacy struct tc_ratespec has a 32bit @rate field
1197 	 * Qdisc using 64bit rate should add new attributes
1198 	 * in order to maintain compatibility.
1199 	 */
1200 	res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
1201 
1202 	res->overhead = r->overhead;
1203 	res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
1204 }
1205 
1206 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
1207  * The fast path only needs to access filter list and to update stats
1208  */
1209 struct mini_Qdisc {
1210 	struct tcf_proto *filter_list;
1211 	struct gnet_stats_basic_cpu __percpu *cpu_bstats;
1212 	struct gnet_stats_queue	__percpu *cpu_qstats;
1213 	struct rcu_head rcu;
1214 };
1215 
1216 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
1217 						const struct sk_buff *skb)
1218 {
1219 	bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
1220 }
1221 
1222 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
1223 {
1224 	this_cpu_inc(miniq->cpu_qstats->drops);
1225 }
1226 
1227 struct mini_Qdisc_pair {
1228 	struct mini_Qdisc miniq1;
1229 	struct mini_Qdisc miniq2;
1230 	struct mini_Qdisc __rcu **p_miniq;
1231 };
1232 
1233 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
1234 			  struct tcf_proto *tp_head);
1235 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
1236 			  struct mini_Qdisc __rcu **p_miniq);
1237 
1238 static inline void skb_tc_reinsert(struct sk_buff *skb, struct tcf_result *res)
1239 {
1240 	struct gnet_stats_queue *stats = res->qstats;
1241 	int ret;
1242 
1243 	if (res->ingress)
1244 		ret = netif_receive_skb(skb);
1245 	else
1246 		ret = dev_queue_xmit(skb);
1247 	if (ret && stats)
1248 		qstats_overlimit_inc(res->qstats);
1249 }
1250 
1251 #endif
1252