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net_sched: transform qdisc running bit into a seqcount
[deliverable/linux.git] / include / net / sch_generic.h
1 #ifndef __NET_SCHED_GENERIC_H
2 #define __NET_SCHED_GENERIC_H
3
4 #include <linux/netdevice.h>
5 #include <linux/types.h>
6 #include <linux/rcupdate.h>
7 #include <linux/pkt_sched.h>
8 #include <linux/pkt_cls.h>
9 #include <linux/percpu.h>
10 #include <linux/dynamic_queue_limits.h>
11 #include <net/gen_stats.h>
12 #include <net/rtnetlink.h>
13
14 struct Qdisc_ops;
15 struct qdisc_walker;
16 struct tcf_walker;
17 struct module;
18
19 struct qdisc_rate_table {
20 struct tc_ratespec rate;
21 u32 data[256];
22 struct qdisc_rate_table *next;
23 int refcnt;
24 };
25
26 enum qdisc_state_t {
27 __QDISC_STATE_SCHED,
28 __QDISC_STATE_DEACTIVATED,
29 __QDISC_STATE_THROTTLED,
30 };
31
32 struct qdisc_size_table {
33 struct rcu_head rcu;
34 struct list_head list;
35 struct tc_sizespec szopts;
36 int refcnt;
37 u16 data[];
38 };
39
40 struct Qdisc {
41 int (*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
42 struct sk_buff * (*dequeue)(struct Qdisc *dev);
43 unsigned int flags;
44 #define TCQ_F_BUILTIN 1
45 #define TCQ_F_INGRESS 2
46 #define TCQ_F_CAN_BYPASS 4
47 #define TCQ_F_MQROOT 8
48 #define TCQ_F_ONETXQUEUE 0x10 /* dequeue_skb() can assume all skbs are for
49 * q->dev_queue : It can test
50 * netif_xmit_frozen_or_stopped() before
51 * dequeueing next packet.
52 * Its true for MQ/MQPRIO slaves, or non
53 * multiqueue device.
54 */
55 #define TCQ_F_WARN_NONWC (1 << 16)
56 #define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */
57 #define TCQ_F_NOPARENT 0x40 /* root of its hierarchy :
58 * qdisc_tree_decrease_qlen() should stop.
59 */
60 u32 limit;
61 const struct Qdisc_ops *ops;
62 struct qdisc_size_table __rcu *stab;
63 struct list_head list;
64 u32 handle;
65 u32 parent;
66 int (*reshape_fail)(struct sk_buff *skb,
67 struct Qdisc *q);
68
69 void *u32_node;
70
71 /* This field is deprecated, but it is still used by CBQ
72 * and it will live until better solution will be invented.
73 */
74 struct Qdisc *__parent;
75 struct netdev_queue *dev_queue;
76
77 struct gnet_stats_rate_est64 rate_est;
78 struct gnet_stats_basic_cpu __percpu *cpu_bstats;
79 struct gnet_stats_queue __percpu *cpu_qstats;
80
81 struct Qdisc *next_sched;
82 struct sk_buff *gso_skb;
83 /*
84 * For performance sake on SMP, we put highly modified fields at the end
85 */
86 unsigned long state;
87 struct sk_buff_head q;
88 struct gnet_stats_basic_packed bstats;
89 seqcount_t running;
90 struct gnet_stats_queue qstats;
91 struct rcu_head rcu_head;
92 int padded;
93 atomic_t refcnt;
94
95 spinlock_t busylock ____cacheline_aligned_in_smp;
96 };
97
98 static inline bool qdisc_is_running(const struct Qdisc *qdisc)
99 {
100 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
101 }
102
103 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
104 {
105 if (qdisc_is_running(qdisc))
106 return false;
107 write_seqcount_begin(&qdisc->running);
108 return true;
109 }
110
111 static inline void qdisc_run_end(struct Qdisc *qdisc)
112 {
113 write_seqcount_end(&qdisc->running);
114 }
115
116 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
117 {
118 return qdisc->flags & TCQ_F_ONETXQUEUE;
119 }
120
121 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
122 {
123 #ifdef CONFIG_BQL
124 /* Non-BQL migrated drivers will return 0, too. */
125 return dql_avail(&txq->dql);
126 #else
127 return 0;
128 #endif
129 }
130
131 static inline bool qdisc_is_throttled(const struct Qdisc *qdisc)
132 {
133 return test_bit(__QDISC_STATE_THROTTLED, &qdisc->state) ? true : false;
134 }
135
136 static inline void qdisc_throttled(struct Qdisc *qdisc)
137 {
138 set_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
139 }
140
141 static inline void qdisc_unthrottled(struct Qdisc *qdisc)
142 {
143 clear_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
144 }
145
146 struct Qdisc_class_ops {
147 /* Child qdisc manipulation */
148 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *);
149 int (*graft)(struct Qdisc *, unsigned long cl,
150 struct Qdisc *, struct Qdisc **);
151 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl);
152 void (*qlen_notify)(struct Qdisc *, unsigned long);
153
154 /* Class manipulation routines */
155 unsigned long (*get)(struct Qdisc *, u32 classid);
156 void (*put)(struct Qdisc *, unsigned long);
157 int (*change)(struct Qdisc *, u32, u32,
158 struct nlattr **, unsigned long *);
159 int (*delete)(struct Qdisc *, unsigned long);
160 void (*walk)(struct Qdisc *, struct qdisc_walker * arg);
161
162 /* Filter manipulation */
163 struct tcf_proto __rcu ** (*tcf_chain)(struct Qdisc *, unsigned long);
164 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long,
165 u32 classid);
166 void (*unbind_tcf)(struct Qdisc *, unsigned long);
167
168 /* rtnetlink specific */
169 int (*dump)(struct Qdisc *, unsigned long,
170 struct sk_buff *skb, struct tcmsg*);
171 int (*dump_stats)(struct Qdisc *, unsigned long,
172 struct gnet_dump *);
173 };
174
175 struct Qdisc_ops {
176 struct Qdisc_ops *next;
177 const struct Qdisc_class_ops *cl_ops;
178 char id[IFNAMSIZ];
179 int priv_size;
180
181 int (*enqueue)(struct sk_buff *, struct Qdisc *);
182 struct sk_buff * (*dequeue)(struct Qdisc *);
183 struct sk_buff * (*peek)(struct Qdisc *);
184 unsigned int (*drop)(struct Qdisc *);
185
186 int (*init)(struct Qdisc *, struct nlattr *arg);
187 void (*reset)(struct Qdisc *);
188 void (*destroy)(struct Qdisc *);
189 int (*change)(struct Qdisc *, struct nlattr *arg);
190 void (*attach)(struct Qdisc *);
191
192 int (*dump)(struct Qdisc *, struct sk_buff *);
193 int (*dump_stats)(struct Qdisc *, struct gnet_dump *);
194
195 struct module *owner;
196 };
197
198
199 struct tcf_result {
200 unsigned long class;
201 u32 classid;
202 };
203
204 struct tcf_proto_ops {
205 struct list_head head;
206 char kind[IFNAMSIZ];
207
208 int (*classify)(struct sk_buff *,
209 const struct tcf_proto *,
210 struct tcf_result *);
211 int (*init)(struct tcf_proto*);
212 bool (*destroy)(struct tcf_proto*, bool);
213
214 unsigned long (*get)(struct tcf_proto*, u32 handle);
215 int (*change)(struct net *net, struct sk_buff *,
216 struct tcf_proto*, unsigned long,
217 u32 handle, struct nlattr **,
218 unsigned long *, bool);
219 int (*delete)(struct tcf_proto*, unsigned long);
220 void (*walk)(struct tcf_proto*, struct tcf_walker *arg);
221
222 /* rtnetlink specific */
223 int (*dump)(struct net*, struct tcf_proto*, unsigned long,
224 struct sk_buff *skb, struct tcmsg*);
225
226 struct module *owner;
227 };
228
229 struct tcf_proto {
230 /* Fast access part */
231 struct tcf_proto __rcu *next;
232 void __rcu *root;
233 int (*classify)(struct sk_buff *,
234 const struct tcf_proto *,
235 struct tcf_result *);
236 __be16 protocol;
237
238 /* All the rest */
239 u32 prio;
240 u32 classid;
241 struct Qdisc *q;
242 void *data;
243 const struct tcf_proto_ops *ops;
244 struct rcu_head rcu;
245 };
246
247 struct qdisc_skb_cb {
248 unsigned int pkt_len;
249 u16 slave_dev_queue_mapping;
250 u16 tc_classid;
251 #define QDISC_CB_PRIV_LEN 20
252 unsigned char data[QDISC_CB_PRIV_LEN];
253 };
254
255 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
256 {
257 struct qdisc_skb_cb *qcb;
258
259 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
260 BUILD_BUG_ON(sizeof(qcb->data) < sz);
261 }
262
263 static inline int qdisc_qlen(const struct Qdisc *q)
264 {
265 return q->q.qlen;
266 }
267
268 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
269 {
270 return (struct qdisc_skb_cb *)skb->cb;
271 }
272
273 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
274 {
275 return &qdisc->q.lock;
276 }
277
278 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
279 {
280 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
281
282 return q;
283 }
284
285 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
286 {
287 return qdisc->dev_queue->qdisc_sleeping;
288 }
289
290 /* The qdisc root lock is a mechanism by which to top level
291 * of a qdisc tree can be locked from any qdisc node in the
292 * forest. This allows changing the configuration of some
293 * aspect of the qdisc tree while blocking out asynchronous
294 * qdisc access in the packet processing paths.
295 *
296 * It is only legal to do this when the root will not change
297 * on us. Otherwise we'll potentially lock the wrong qdisc
298 * root. This is enforced by holding the RTNL semaphore, which
299 * all users of this lock accessor must do.
300 */
301 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
302 {
303 struct Qdisc *root = qdisc_root(qdisc);
304
305 ASSERT_RTNL();
306 return qdisc_lock(root);
307 }
308
309 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
310 {
311 struct Qdisc *root = qdisc_root_sleeping(qdisc);
312
313 ASSERT_RTNL();
314 return qdisc_lock(root);
315 }
316
317 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
318 {
319 return qdisc->dev_queue->dev;
320 }
321
322 static inline void sch_tree_lock(const struct Qdisc *q)
323 {
324 spin_lock_bh(qdisc_root_sleeping_lock(q));
325 }
326
327 static inline void sch_tree_unlock(const struct Qdisc *q)
328 {
329 spin_unlock_bh(qdisc_root_sleeping_lock(q));
330 }
331
332 #define tcf_tree_lock(tp) sch_tree_lock((tp)->q)
333 #define tcf_tree_unlock(tp) sch_tree_unlock((tp)->q)
334
335 extern struct Qdisc noop_qdisc;
336 extern struct Qdisc_ops noop_qdisc_ops;
337 extern struct Qdisc_ops pfifo_fast_ops;
338 extern struct Qdisc_ops mq_qdisc_ops;
339 extern struct Qdisc_ops noqueue_qdisc_ops;
340 extern const struct Qdisc_ops *default_qdisc_ops;
341 static inline const struct Qdisc_ops *
342 get_default_qdisc_ops(const struct net_device *dev, int ntx)
343 {
344 return ntx < dev->real_num_tx_queues ?
345 default_qdisc_ops : &pfifo_fast_ops;
346 }
347
348 struct Qdisc_class_common {
349 u32 classid;
350 struct hlist_node hnode;
351 };
352
353 struct Qdisc_class_hash {
354 struct hlist_head *hash;
355 unsigned int hashsize;
356 unsigned int hashmask;
357 unsigned int hashelems;
358 };
359
360 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
361 {
362 id ^= id >> 8;
363 id ^= id >> 4;
364 return id & mask;
365 }
366
367 static inline struct Qdisc_class_common *
368 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
369 {
370 struct Qdisc_class_common *cl;
371 unsigned int h;
372
373 h = qdisc_class_hash(id, hash->hashmask);
374 hlist_for_each_entry(cl, &hash->hash[h], hnode) {
375 if (cl->classid == id)
376 return cl;
377 }
378 return NULL;
379 }
380
381 int qdisc_class_hash_init(struct Qdisc_class_hash *);
382 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
383 struct Qdisc_class_common *);
384 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
385 struct Qdisc_class_common *);
386 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
387 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
388
389 void dev_init_scheduler(struct net_device *dev);
390 void dev_shutdown(struct net_device *dev);
391 void dev_activate(struct net_device *dev);
392 void dev_deactivate(struct net_device *dev);
393 void dev_deactivate_many(struct list_head *head);
394 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
395 struct Qdisc *qdisc);
396 void qdisc_reset(struct Qdisc *qdisc);
397 void qdisc_destroy(struct Qdisc *qdisc);
398 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
399 unsigned int len);
400 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
401 const struct Qdisc_ops *ops);
402 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
403 const struct Qdisc_ops *ops, u32 parentid);
404 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
405 const struct qdisc_size_table *stab);
406 bool tcf_destroy(struct tcf_proto *tp, bool force);
407 void tcf_destroy_chain(struct tcf_proto __rcu **fl);
408 int skb_do_redirect(struct sk_buff *);
409
410 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
411 {
412 #ifdef CONFIG_NET_CLS_ACT
413 return G_TC_AT(skb->tc_verd) & AT_INGRESS;
414 #else
415 return false;
416 #endif
417 }
418
419 /* Reset all TX qdiscs greater then index of a device. */
420 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
421 {
422 struct Qdisc *qdisc;
423
424 for (; i < dev->num_tx_queues; i++) {
425 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
426 if (qdisc) {
427 spin_lock_bh(qdisc_lock(qdisc));
428 qdisc_reset(qdisc);
429 spin_unlock_bh(qdisc_lock(qdisc));
430 }
431 }
432 }
433
434 static inline void qdisc_reset_all_tx(struct net_device *dev)
435 {
436 qdisc_reset_all_tx_gt(dev, 0);
437 }
438
439 /* Are all TX queues of the device empty? */
440 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
441 {
442 unsigned int i;
443
444 rcu_read_lock();
445 for (i = 0; i < dev->num_tx_queues; i++) {
446 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
447 const struct Qdisc *q = rcu_dereference(txq->qdisc);
448
449 if (q->q.qlen) {
450 rcu_read_unlock();
451 return false;
452 }
453 }
454 rcu_read_unlock();
455 return true;
456 }
457
458 /* Are any of the TX qdiscs changing? */
459 static inline bool qdisc_tx_changing(const struct net_device *dev)
460 {
461 unsigned int i;
462
463 for (i = 0; i < dev->num_tx_queues; i++) {
464 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
465 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
466 return true;
467 }
468 return false;
469 }
470
471 /* Is the device using the noop qdisc on all queues? */
472 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
473 {
474 unsigned int i;
475
476 for (i = 0; i < dev->num_tx_queues; i++) {
477 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
478 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
479 return false;
480 }
481 return true;
482 }
483
484 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
485 {
486 return qdisc_skb_cb(skb)->pkt_len;
487 }
488
489 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
490 enum net_xmit_qdisc_t {
491 __NET_XMIT_STOLEN = 0x00010000,
492 __NET_XMIT_BYPASS = 0x00020000,
493 };
494
495 #ifdef CONFIG_NET_CLS_ACT
496 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1)
497 #else
498 #define net_xmit_drop_count(e) (1)
499 #endif
500
501 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
502 const struct Qdisc *sch)
503 {
504 #ifdef CONFIG_NET_SCHED
505 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
506
507 if (stab)
508 __qdisc_calculate_pkt_len(skb, stab);
509 #endif
510 }
511
512 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
513 {
514 qdisc_calculate_pkt_len(skb, sch);
515 return sch->enqueue(skb, sch);
516 }
517
518 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
519 {
520 return q->flags & TCQ_F_CPUSTATS;
521 }
522
523 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
524 __u64 bytes, __u32 packets)
525 {
526 bstats->bytes += bytes;
527 bstats->packets += packets;
528 }
529
530 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
531 const struct sk_buff *skb)
532 {
533 _bstats_update(bstats,
534 qdisc_pkt_len(skb),
535 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
536 }
537
538 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
539 __u64 bytes, __u32 packets)
540 {
541 u64_stats_update_begin(&bstats->syncp);
542 _bstats_update(&bstats->bstats, bytes, packets);
543 u64_stats_update_end(&bstats->syncp);
544 }
545
546 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
547 const struct sk_buff *skb)
548 {
549 u64_stats_update_begin(&bstats->syncp);
550 bstats_update(&bstats->bstats, skb);
551 u64_stats_update_end(&bstats->syncp);
552 }
553
554 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
555 const struct sk_buff *skb)
556 {
557 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
558 }
559
560 static inline void qdisc_bstats_update(struct Qdisc *sch,
561 const struct sk_buff *skb)
562 {
563 bstats_update(&sch->bstats, skb);
564 }
565
566 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
567 const struct sk_buff *skb)
568 {
569 sch->qstats.backlog -= qdisc_pkt_len(skb);
570 }
571
572 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
573 const struct sk_buff *skb)
574 {
575 sch->qstats.backlog += qdisc_pkt_len(skb);
576 }
577
578 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
579 {
580 sch->qstats.drops += count;
581 }
582
583 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
584 {
585 qstats->drops++;
586 }
587
588 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
589 {
590 qstats->overlimits++;
591 }
592
593 static inline void qdisc_qstats_drop(struct Qdisc *sch)
594 {
595 qstats_drop_inc(&sch->qstats);
596 }
597
598 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
599 {
600 qstats_drop_inc(this_cpu_ptr(sch->cpu_qstats));
601 }
602
603 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
604 {
605 sch->qstats.overlimits++;
606 }
607
608 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
609 struct sk_buff_head *list)
610 {
611 __skb_queue_tail(list, skb);
612 qdisc_qstats_backlog_inc(sch, skb);
613
614 return NET_XMIT_SUCCESS;
615 }
616
617 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
618 {
619 return __qdisc_enqueue_tail(skb, sch, &sch->q);
620 }
621
622 static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
623 struct sk_buff_head *list)
624 {
625 struct sk_buff *skb = __skb_dequeue(list);
626
627 if (likely(skb != NULL)) {
628 qdisc_qstats_backlog_dec(sch, skb);
629 qdisc_bstats_update(sch, skb);
630 }
631
632 return skb;
633 }
634
635 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
636 {
637 return __qdisc_dequeue_head(sch, &sch->q);
638 }
639
640 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
641 struct sk_buff_head *list)
642 {
643 struct sk_buff *skb = __skb_dequeue(list);
644
645 if (likely(skb != NULL)) {
646 unsigned int len = qdisc_pkt_len(skb);
647 qdisc_qstats_backlog_dec(sch, skb);
648 kfree_skb(skb);
649 return len;
650 }
651
652 return 0;
653 }
654
655 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
656 {
657 return __qdisc_queue_drop_head(sch, &sch->q);
658 }
659
660 static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
661 struct sk_buff_head *list)
662 {
663 struct sk_buff *skb = __skb_dequeue_tail(list);
664
665 if (likely(skb != NULL))
666 qdisc_qstats_backlog_dec(sch, skb);
667
668 return skb;
669 }
670
671 static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
672 {
673 return __qdisc_dequeue_tail(sch, &sch->q);
674 }
675
676 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
677 {
678 return skb_peek(&sch->q);
679 }
680
681 /* generic pseudo peek method for non-work-conserving qdisc */
682 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
683 {
684 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
685 if (!sch->gso_skb) {
686 sch->gso_skb = sch->dequeue(sch);
687 if (sch->gso_skb)
688 /* it's still part of the queue */
689 sch->q.qlen++;
690 }
691
692 return sch->gso_skb;
693 }
694
695 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
696 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
697 {
698 struct sk_buff *skb = sch->gso_skb;
699
700 if (skb) {
701 sch->gso_skb = NULL;
702 sch->q.qlen--;
703 } else {
704 skb = sch->dequeue(sch);
705 }
706
707 return skb;
708 }
709
710 static inline void __qdisc_reset_queue(struct Qdisc *sch,
711 struct sk_buff_head *list)
712 {
713 /*
714 * We do not know the backlog in bytes of this list, it
715 * is up to the caller to correct it
716 */
717 __skb_queue_purge(list);
718 }
719
720 static inline void qdisc_reset_queue(struct Qdisc *sch)
721 {
722 __qdisc_reset_queue(sch, &sch->q);
723 sch->qstats.backlog = 0;
724 }
725
726 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
727 struct Qdisc **pold)
728 {
729 struct Qdisc *old;
730
731 sch_tree_lock(sch);
732 old = *pold;
733 *pold = new;
734 if (old != NULL) {
735 qdisc_tree_reduce_backlog(old, old->q.qlen, old->qstats.backlog);
736 qdisc_reset(old);
737 }
738 sch_tree_unlock(sch);
739
740 return old;
741 }
742
743 static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
744 struct sk_buff_head *list)
745 {
746 struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
747
748 if (likely(skb != NULL)) {
749 unsigned int len = qdisc_pkt_len(skb);
750 kfree_skb(skb);
751 return len;
752 }
753
754 return 0;
755 }
756
757 static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
758 {
759 return __qdisc_queue_drop(sch, &sch->q);
760 }
761
762 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
763 {
764 kfree_skb(skb);
765 qdisc_qstats_drop(sch);
766
767 return NET_XMIT_DROP;
768 }
769
770 static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
771 {
772 qdisc_qstats_drop(sch);
773
774 #ifdef CONFIG_NET_CLS_ACT
775 if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
776 goto drop;
777
778 return NET_XMIT_SUCCESS;
779
780 drop:
781 #endif
782 kfree_skb(skb);
783 return NET_XMIT_DROP;
784 }
785
786 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
787 long it will take to send a packet given its size.
788 */
789 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
790 {
791 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
792 if (slot < 0)
793 slot = 0;
794 slot >>= rtab->rate.cell_log;
795 if (slot > 255)
796 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
797 return rtab->data[slot];
798 }
799
800 struct psched_ratecfg {
801 u64 rate_bytes_ps; /* bytes per second */
802 u32 mult;
803 u16 overhead;
804 u8 linklayer;
805 u8 shift;
806 };
807
808 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
809 unsigned int len)
810 {
811 len += r->overhead;
812
813 if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
814 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
815
816 return ((u64)len * r->mult) >> r->shift;
817 }
818
819 void psched_ratecfg_precompute(struct psched_ratecfg *r,
820 const struct tc_ratespec *conf,
821 u64 rate64);
822
823 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
824 const struct psched_ratecfg *r)
825 {
826 memset(res, 0, sizeof(*res));
827
828 /* legacy struct tc_ratespec has a 32bit @rate field
829 * Qdisc using 64bit rate should add new attributes
830 * in order to maintain compatibility.
831 */
832 res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
833
834 res->overhead = r->overhead;
835 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
836 }
837
838 #endif
Linux kernel - Deliverables
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