1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/sch_htb.c Hierarchical token bucket, feed tree version
4 *
5 * Authors: Martin Devera, <devik@cdi.cz>
6 *
7 * Credits (in time order) for older HTB versions:
8 * Stef Coene <stef.coene@docum.org>
9 * HTB support at LARTC mailing list
10 * Ondrej Kraus, <krauso@barr.cz>
11 * found missing INIT_QDISC(htb)
12 * Vladimir Smelhaus, Aamer Akhter, Bert Hubert
13 * helped a lot to locate nasty class stall bug
14 * Andi Kleen, Jamal Hadi, Bert Hubert
15 * code review and helpful comments on shaping
16 * Tomasz Wrona, <tw@eter.tym.pl>
17 * created test case so that I was able to fix nasty bug
18 * Wilfried Weissmann
19 * spotted bug in dequeue code and helped with fix
20 * Jiri Fojtasek
21 * fixed requeue routine
22 * and many others. thanks.
23 */
24 #include <linux/module.h>
25 #include <linux/moduleparam.h>
26 #include <linux/types.h>
27 #include <linux/kernel.h>
28 #include <linux/string.h>
29 #include <linux/errno.h>
30 #include <linux/skbuff.h>
31 #include <linux/list.h>
32 #include <linux/compiler.h>
33 #include <linux/rbtree.h>
34 #include <linux/workqueue.h>
35 #include <linux/slab.h>
36 #include <net/netlink.h>
37 #include <net/sch_generic.h>
38 #include <net/pkt_sched.h>
39 #include <net/pkt_cls.h>
40
41 /* HTB algorithm.
42 Author: devik@cdi.cz
43 ========================================================================
44 HTB is like TBF with multiple classes. It is also similar to CBQ because
45 it allows to assign priority to each class in hierarchy.
46 In fact it is another implementation of Floyd's formal sharing.
47
48 Levels:
49 Each class is assigned level. Leaf has ALWAYS level 0 and root
50 classes have level TC_HTB_MAXDEPTH-1. Interior nodes has level
51 one less than their parent.
52 */
53
54 static int htb_hysteresis __read_mostly = 0; /* whether to use mode hysteresis for speedup */
55 #define HTB_VER 0x30011 /* major must be matched with number supplied by TC as version */
56
57 #if HTB_VER >> 16 != TC_HTB_PROTOVER
58 #error "Mismatched sch_htb.c and pkt_sch.h"
59 #endif
60
61 /* Module parameter and sysfs export */
62 module_param (htb_hysteresis, int, 0640);
63 MODULE_PARM_DESC(htb_hysteresis, "Hysteresis mode, less CPU load, less accurate");
64
65 static int htb_rate_est = 0; /* htb classes have a default rate estimator */
66 module_param(htb_rate_est, int, 0640);
67 MODULE_PARM_DESC(htb_rate_est, "setup a default rate estimator (4sec 16sec) for htb classes");
68
69 /* used internaly to keep status of single class */
70 enum htb_cmode {
71 HTB_CANT_SEND, /* class can't send and can't borrow */
72 HTB_MAY_BORROW, /* class can't send but may borrow */
73 HTB_CAN_SEND /* class can send */
74 };
75
76 struct htb_prio {
77 union {
78 struct rb_root row;
79 struct rb_root feed;
80 };
81 struct rb_node *ptr;
82 /* When class changes from state 1->2 and disconnects from
83 * parent's feed then we lost ptr value and start from the
84 * first child again. Here we store classid of the
85 * last valid ptr (used when ptr is NULL).
86 */
87 u32 last_ptr_id;
88 };
89
90 /* interior & leaf nodes; props specific to leaves are marked L:
91 * To reduce false sharing, place mostly read fields at beginning,
92 * and mostly written ones at the end.
93 */
94 struct htb_class {
95 struct Qdisc_class_common common;
96 struct psched_ratecfg rate;
97 struct psched_ratecfg ceil;
98 s64 buffer, cbuffer;/* token bucket depth/rate */
99 s64 mbuffer; /* max wait time */
100 u32 prio; /* these two are used only by leaves... */
101 int quantum; /* but stored for parent-to-leaf return */
102
103 struct tcf_proto __rcu *filter_list; /* class attached filters */
104 struct tcf_block *block;
105
106 int level; /* our level (see above) */
107 unsigned int children;
108 struct htb_class *parent; /* parent class */
109
110 struct net_rate_estimator __rcu *rate_est;
111
112 /*
113 * Written often fields
114 */
115 struct gnet_stats_basic_sync bstats;
116 struct gnet_stats_basic_sync bstats_bias;
117 struct tc_htb_xstats xstats; /* our special stats */
118
119 /* token bucket parameters */
120 s64 tokens, ctokens;/* current number of tokens */
121 s64 t_c; /* checkpoint time */
122
123 union {
124 struct htb_class_leaf {
125 int deficit[TC_HTB_MAXDEPTH];
126 struct Qdisc *q;
127 struct netdev_queue *offload_queue;
128 } leaf;
129 struct htb_class_inner {
130 struct htb_prio clprio[TC_HTB_NUMPRIO];
131 } inner;
132 };
133 s64 pq_key;
134
135 int prio_activity; /* for which prios are we active */
136 enum htb_cmode cmode; /* current mode of the class */
137 struct rb_node pq_node; /* node for event queue */
138 struct rb_node node[TC_HTB_NUMPRIO]; /* node for self or feed tree */
139
140 unsigned int drops ____cacheline_aligned_in_smp;
141 unsigned int overlimits;
142 };
143
144 struct htb_level {
145 struct rb_root wait_pq;
146 struct htb_prio hprio[TC_HTB_NUMPRIO];
147 };
148
149 struct htb_sched {
150 struct Qdisc_class_hash clhash;
151 int defcls; /* class where unclassified flows go to */
152 int rate2quantum; /* quant = rate / rate2quantum */
153
154 /* filters for qdisc itself */
155 struct tcf_proto __rcu *filter_list;
156 struct tcf_block *block;
157
158 #define HTB_WARN_TOOMANYEVENTS 0x1
159 unsigned int warned; /* only one warning */
160 int direct_qlen;
161 struct work_struct work;
162
163 /* non shaped skbs; let them go directly thru */
164 struct qdisc_skb_head direct_queue;
165 u32 direct_pkts;
166 u32 overlimits;
167
168 struct qdisc_watchdog watchdog;
169
170 s64 now; /* cached dequeue time */
171
172 /* time of nearest event per level (row) */
173 s64 near_ev_cache[TC_HTB_MAXDEPTH];
174
175 int row_mask[TC_HTB_MAXDEPTH];
176
177 struct htb_level hlevel[TC_HTB_MAXDEPTH];
178
179 struct Qdisc **direct_qdiscs;
180 unsigned int num_direct_qdiscs;
181
182 bool offload;
183 };
184
185 /* find class in global hash table using given handle */
186 static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)
187 {
188 struct htb_sched *q = qdisc_priv(sch);
189 struct Qdisc_class_common *clc;
190
191 clc = qdisc_class_find(&q->clhash, handle);
192 if (clc == NULL)
193 return NULL;
194 return container_of(clc, struct htb_class, common);
195 }
196
197 static unsigned long htb_search(struct Qdisc *sch, u32 handle)
198 {
199 return (unsigned long)htb_find(handle, sch);
200 }
201
202 #define HTB_DIRECT ((struct htb_class *)-1L)
203
204 /**
205 * htb_classify - classify a packet into class
206 * @skb: the socket buffer
207 * @sch: the active queue discipline
208 * @qerr: pointer for returned status code
209 *
210 * It returns NULL if the packet should be dropped or -1 if the packet
211 * should be passed directly thru. In all other cases leaf class is returned.
212 * We allow direct class selection by classid in priority. The we examine
213 * filters in qdisc and in inner nodes (if higher filter points to the inner
214 * node). If we end up with classid MAJOR:0 we enqueue the skb into special
215 * internal fifo (direct). These packets then go directly thru. If we still
216 * have no valid leaf we try to use MAJOR:default leaf. It still unsuccessful
217 * then finish and return direct queue.
218 */
219 static struct htb_class *htb_classify(struct sk_buff *skb, struct Qdisc *sch,
220 int *qerr)
221 {
222 struct htb_sched *q = qdisc_priv(sch);
223 struct htb_class *cl;
224 struct tcf_result res;
225 struct tcf_proto *tcf;
226 int result;
227
228 /* allow to select class by setting skb->priority to valid classid;
229 * note that nfmark can be used too by attaching filter fw with no
230 * rules in it
231 */
232 if (skb->priority == sch->handle)
233 return HTB_DIRECT; /* X:0 (direct flow) selected */
234 cl = htb_find(skb->priority, sch);
235 if (cl) {
236 if (cl->level == 0)
237 return cl;
238 /* Start with inner filter chain if a non-leaf class is selected */
239 tcf = rcu_dereference_bh(cl->filter_list);
240 } else {
241 tcf = rcu_dereference_bh(q->filter_list);
242 }
243
244 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
245 while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
246 #ifdef CONFIG_NET_CLS_ACT
247 switch (result) {
248 case TC_ACT_QUEUED:
249 case TC_ACT_STOLEN:
250 case TC_ACT_TRAP:
251 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
252 fallthrough;
253 case TC_ACT_SHOT:
254 return NULL;
255 }
256 #endif
257 cl = (void *)res.class;
258 if (!cl) {
259 if (res.classid == sch->handle)
260 return HTB_DIRECT; /* X:0 (direct flow) */
261 cl = htb_find(res.classid, sch);
262 if (!cl)
263 break; /* filter selected invalid classid */
264 }
265 if (!cl->level)
266 return cl; /* we hit leaf; return it */
267
268 /* we have got inner class; apply inner filter chain */
269 tcf = rcu_dereference_bh(cl->filter_list);
270 }
271 /* classification failed; try to use default class */
272 cl = htb_find(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
273 if (!cl || cl->level)
274 return HTB_DIRECT; /* bad default .. this is safe bet */
275 return cl;
276 }
277
278 /**
279 * htb_add_to_id_tree - adds class to the round robin list
280 * @root: the root of the tree
281 * @cl: the class to add
282 * @prio: the give prio in class
283 *
284 * Routine adds class to the list (actually tree) sorted by classid.
285 * Make sure that class is not already on such list for given prio.
286 */
287 static void htb_add_to_id_tree(struct rb_root *root,
288 struct htb_class *cl, int prio)
289 {
290 struct rb_node **p = &root->rb_node, *parent = NULL;
291
292 while (*p) {
293 struct htb_class *c;
294 parent = *p;
295 c = rb_entry(parent, struct htb_class, node[prio]);
296
297 if (cl->common.classid > c->common.classid)
298 p = &parent->rb_right;
299 else
300 p = &parent->rb_left;
301 }
302 rb_link_node(&cl->node[prio], parent, p);
303 rb_insert_color(&cl->node[prio], root);
304 }
305
306 /**
307 * htb_add_to_wait_tree - adds class to the event queue with delay
308 * @q: the priority event queue
309 * @cl: the class to add
310 * @delay: delay in microseconds
311 *
312 * The class is added to priority event queue to indicate that class will
313 * change its mode in cl->pq_key microseconds. Make sure that class is not
314 * already in the queue.
315 */
316 static void htb_add_to_wait_tree(struct htb_sched *q,
317 struct htb_class *cl, s64 delay)
318 {
319 struct rb_node **p = &q->hlevel[cl->level].wait_pq.rb_node, *parent = NULL;
320
321 cl->pq_key = q->now + delay;
322 if (cl->pq_key == q->now)
323 cl->pq_key++;
324
325 /* update the nearest event cache */
326 if (q->near_ev_cache[cl->level] > cl->pq_key)
327 q->near_ev_cache[cl->level] = cl->pq_key;
328
329 while (*p) {
330 struct htb_class *c;
331 parent = *p;
332 c = rb_entry(parent, struct htb_class, pq_node);
333 if (cl->pq_key >= c->pq_key)
334 p = &parent->rb_right;
335 else
336 p = &parent->rb_left;
337 }
338 rb_link_node(&cl->pq_node, parent, p);
339 rb_insert_color(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
340 }
341
342 /**
343 * htb_next_rb_node - finds next node in binary tree
344 * @n: the current node in binary tree
345 *
346 * When we are past last key we return NULL.
347 * Average complexity is 2 steps per call.
348 */
349 static inline void htb_next_rb_node(struct rb_node **n)
350 {
351 *n = rb_next(*n);
352 }
353
354 /**
355 * htb_add_class_to_row - add class to its row
356 * @q: the priority event queue
357 * @cl: the class to add
358 * @mask: the given priorities in class in bitmap
359 *
360 * The class is added to row at priorities marked in mask.
361 * It does nothing if mask == 0.
362 */
363 static inline void htb_add_class_to_row(struct htb_sched *q,
364 struct htb_class *cl, int mask)
365 {
366 q->row_mask[cl->level] |= mask;
367 while (mask) {
368 int prio = ffz(~mask);
369 mask &= ~(1 << prio);
370 htb_add_to_id_tree(&q->hlevel[cl->level].hprio[prio].row, cl, prio);
371 }
372 }
373
374 /* If this triggers, it is a bug in this code, but it need not be fatal */
375 static void htb_safe_rb_erase(struct rb_node *rb, struct rb_root *root)
376 {
377 if (RB_EMPTY_NODE(rb)) {
378 WARN_ON(1);
379 } else {
380 rb_erase(rb, root);
381 RB_CLEAR_NODE(rb);
382 }
383 }
384
385
386 /**
387 * htb_remove_class_from_row - removes class from its row
388 * @q: the priority event queue
389 * @cl: the class to add
390 * @mask: the given priorities in class in bitmap
391 *
392 * The class is removed from row at priorities marked in mask.
393 * It does nothing if mask == 0.
394 */
395 static inline void htb_remove_class_from_row(struct htb_sched *q,
396 struct htb_class *cl, int mask)
397 {
398 int m = 0;
399 struct htb_level *hlevel = &q->hlevel[cl->level];
400
401 while (mask) {
402 int prio = ffz(~mask);
403 struct htb_prio *hprio = &hlevel->hprio[prio];
404
405 mask &= ~(1 << prio);
406 if (hprio->ptr == cl->node + prio)
407 htb_next_rb_node(&hprio->ptr);
408
409 htb_safe_rb_erase(cl->node + prio, &hprio->row);
410 if (!hprio->row.rb_node)
411 m |= 1 << prio;
412 }
413 q->row_mask[cl->level] &= ~m;
414 }
415
416 /**
417 * htb_activate_prios - creates active classe's feed chain
418 * @q: the priority event queue
419 * @cl: the class to activate
420 *
421 * The class is connected to ancestors and/or appropriate rows
422 * for priorities it is participating on. cl->cmode must be new
423 * (activated) mode. It does nothing if cl->prio_activity == 0.
424 */
425 static void htb_activate_prios(struct htb_sched *q, struct htb_class *cl)
426 {
427 struct htb_class *p = cl->parent;
428 long m, mask = cl->prio_activity;
429
430 while (cl->cmode == HTB_MAY_BORROW && p && mask) {
431 m = mask;
432 while (m) {
433 unsigned int prio = ffz(~m);
434
435 if (WARN_ON_ONCE(prio >= ARRAY_SIZE(p->inner.clprio)))
436 break;
437 m &= ~(1 << prio);
438
439 if (p->inner.clprio[prio].feed.rb_node)
440 /* parent already has its feed in use so that
441 * reset bit in mask as parent is already ok
442 */
443 mask &= ~(1 << prio);
444
445 htb_add_to_id_tree(&p->inner.clprio[prio].feed, cl, prio);
446 }
447 p->prio_activity |= mask;
448 cl = p;
449 p = cl->parent;
450
451 }
452 if (cl->cmode == HTB_CAN_SEND && mask)
453 htb_add_class_to_row(q, cl, mask);
454 }
455
456 /**
457 * htb_deactivate_prios - remove class from feed chain
458 * @q: the priority event queue
459 * @cl: the class to deactivate
460 *
461 * cl->cmode must represent old mode (before deactivation). It does
462 * nothing if cl->prio_activity == 0. Class is removed from all feed
463 * chains and rows.
464 */
465 static void htb_deactivate_prios(struct htb_sched *q, struct htb_class *cl)
466 {
467 struct htb_class *p = cl->parent;
468 long m, mask = cl->prio_activity;
469
470 while (cl->cmode == HTB_MAY_BORROW && p && mask) {
471 m = mask;
472 mask = 0;
473 while (m) {
474 int prio = ffz(~m);
475 m &= ~(1 << prio);
476
477 if (p->inner.clprio[prio].ptr == cl->node + prio) {
478 /* we are removing child which is pointed to from
479 * parent feed - forget the pointer but remember
480 * classid
481 */
482 p->inner.clprio[prio].last_ptr_id = cl->common.classid;
483 p->inner.clprio[prio].ptr = NULL;
484 }
485
486 htb_safe_rb_erase(cl->node + prio,
487 &p->inner.clprio[prio].feed);
488
489 if (!p->inner.clprio[prio].feed.rb_node)
490 mask |= 1 << prio;
491 }
492
493 p->prio_activity &= ~mask;
494 cl = p;
495 p = cl->parent;
496
497 }
498 if (cl->cmode == HTB_CAN_SEND && mask)
499 htb_remove_class_from_row(q, cl, mask);
500 }
501
502 static inline s64 htb_lowater(const struct htb_class *cl)
503 {
504 if (htb_hysteresis)
505 return cl->cmode != HTB_CANT_SEND ? -cl->cbuffer : 0;
506 else
507 return 0;
508 }
509 static inline s64 htb_hiwater(const struct htb_class *cl)
510 {
511 if (htb_hysteresis)
512 return cl->cmode == HTB_CAN_SEND ? -cl->buffer : 0;
513 else
514 return 0;
515 }
516
517
518 /**
519 * htb_class_mode - computes and returns current class mode
520 * @cl: the target class
521 * @diff: diff time in microseconds
522 *
523 * It computes cl's mode at time cl->t_c+diff and returns it. If mode
524 * is not HTB_CAN_SEND then cl->pq_key is updated to time difference
525 * from now to time when cl will change its state.
526 * Also it is worth to note that class mode doesn't change simply
527 * at cl->{c,}tokens == 0 but there can rather be hysteresis of
528 * 0 .. -cl->{c,}buffer range. It is meant to limit number of
529 * mode transitions per time unit. The speed gain is about 1/6.
530 */
531 static inline enum htb_cmode
532 htb_class_mode(struct htb_class *cl, s64 *diff)
533 {
534 s64 toks;
535
536 if ((toks = (cl->ctokens + *diff)) < htb_lowater(cl)) {
537 *diff = -toks;
538 return HTB_CANT_SEND;
539 }
540
541 if ((toks = (cl->tokens + *diff)) >= htb_hiwater(cl))
542 return HTB_CAN_SEND;
543
544 *diff = -toks;
545 return HTB_MAY_BORROW;
546 }
547
548 /**
549 * htb_change_class_mode - changes classe's mode
550 * @q: the priority event queue
551 * @cl: the target class
552 * @diff: diff time in microseconds
553 *
554 * This should be the only way how to change classe's mode under normal
555 * circumstances. Routine will update feed lists linkage, change mode
556 * and add class to the wait event queue if appropriate. New mode should
557 * be different from old one and cl->pq_key has to be valid if changing
558 * to mode other than HTB_CAN_SEND (see htb_add_to_wait_tree).
559 */
560 static void
561 htb_change_class_mode(struct htb_sched *q, struct htb_class *cl, s64 *diff)
562 {
563 enum htb_cmode new_mode = htb_class_mode(cl, diff);
564
565 if (new_mode == cl->cmode)
566 return;
567
568 if (new_mode == HTB_CANT_SEND) {
569 cl->overlimits++;
570 q->overlimits++;
571 }
572
573 if (cl->prio_activity) { /* not necessary: speed optimization */
574 if (cl->cmode != HTB_CANT_SEND)
575 htb_deactivate_prios(q, cl);
576 cl->cmode = new_mode;
577 if (new_mode != HTB_CANT_SEND)
578 htb_activate_prios(q, cl);
579 } else
580 cl->cmode = new_mode;
581 }
582
583 /**
584 * htb_activate - inserts leaf cl into appropriate active feeds
585 * @q: the priority event queue
586 * @cl: the target class
587 *
588 * Routine learns (new) priority of leaf and activates feed chain
589 * for the prio. It can be called on already active leaf safely.
590 * It also adds leaf into droplist.
591 */
592 static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
593 {
594 WARN_ON(cl->level || !cl->leaf.q || !cl->leaf.q->q.qlen);
595
596 if (!cl->prio_activity) {
597 cl->prio_activity = 1 << cl->prio;
598 htb_activate_prios(q, cl);
599 }
600 }
601
602 /**
603 * htb_deactivate - remove leaf cl from active feeds
604 * @q: the priority event queue
605 * @cl: the target class
606 *
607 * Make sure that leaf is active. In the other words it can't be called
608 * with non-active leaf. It also removes class from the drop list.
609 */
610 static inline void htb_deactivate(struct htb_sched *q, struct htb_class *cl)
611 {
612 WARN_ON(!cl->prio_activity);
613
614 htb_deactivate_prios(q, cl);
615 cl->prio_activity = 0;
616 }
617
618 static int htb_enqueue(struct sk_buff *skb, struct Qdisc *sch,
619 struct sk_buff **to_free)
620 {
621 int ret;
622 unsigned int len = qdisc_pkt_len(skb);
623 struct htb_sched *q = qdisc_priv(sch);
624 struct htb_class *cl = htb_classify(skb, sch, &ret);
625
626 if (cl == HTB_DIRECT) {
627 /* enqueue to helper queue */
628 if (q->direct_queue.qlen < q->direct_qlen) {
629 __qdisc_enqueue_tail(skb, &q->direct_queue);
630 q->direct_pkts++;
631 } else {
632 return qdisc_drop(skb, sch, to_free);
633 }
634 #ifdef CONFIG_NET_CLS_ACT
635 } else if (!cl) {
636 if (ret & __NET_XMIT_BYPASS)
637 qdisc_qstats_drop(sch);
638 __qdisc_drop(skb, to_free);
639 return ret;
640 #endif
641 } else if ((ret = qdisc_enqueue(skb, cl->leaf.q,
642 to_free)) != NET_XMIT_SUCCESS) {
643 if (net_xmit_drop_count(ret)) {
644 qdisc_qstats_drop(sch);
645 cl->drops++;
646 }
647 return ret;
648 } else {
649 htb_activate(q, cl);
650 }
651
652 sch->qstats.backlog += len;
653 sch->q.qlen++;
654 return NET_XMIT_SUCCESS;
655 }
656
657 static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff)
658 {
659 s64 toks = diff + cl->tokens;
660
661 if (toks > cl->buffer)
662 toks = cl->buffer;
663 toks -= (s64) psched_l2t_ns(&cl->rate, bytes);
664 if (toks <= -cl->mbuffer)
665 toks = 1 - cl->mbuffer;
666
667 cl->tokens = toks;
668 }
669
670 static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff)
671 {
672 s64 toks = diff + cl->ctokens;
673
674 if (toks > cl->cbuffer)
675 toks = cl->cbuffer;
676 toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);
677 if (toks <= -cl->mbuffer)
678 toks = 1 - cl->mbuffer;
679
680 cl->ctokens = toks;
681 }
682
683 /**
684 * htb_charge_class - charges amount "bytes" to leaf and ancestors
685 * @q: the priority event queue
686 * @cl: the class to start iterate
687 * @level: the minimum level to account
688 * @skb: the socket buffer
689 *
690 * Routine assumes that packet "bytes" long was dequeued from leaf cl
691 * borrowing from "level". It accounts bytes to ceil leaky bucket for
692 * leaf and all ancestors and to rate bucket for ancestors at levels
693 * "level" and higher. It also handles possible change of mode resulting
694 * from the update. Note that mode can also increase here (MAY_BORROW to
695 * CAN_SEND) because we can use more precise clock that event queue here.
696 * In such case we remove class from event queue first.
697 */
698 static void htb_charge_class(struct htb_sched *q, struct htb_class *cl,
699 int level, struct sk_buff *skb)
700 {
701 int bytes = qdisc_pkt_len(skb);
702 enum htb_cmode old_mode;
703 s64 diff;
704
705 while (cl) {
706 diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
707 if (cl->level >= level) {
708 if (cl->level == level)
709 cl->xstats.lends++;
710 htb_accnt_tokens(cl, bytes, diff);
711 } else {
712 cl->xstats.borrows++;
713 cl->tokens += diff; /* we moved t_c; update tokens */
714 }
715 htb_accnt_ctokens(cl, bytes, diff);
716 cl->t_c = q->now;
717
718 old_mode = cl->cmode;
719 diff = 0;
720 htb_change_class_mode(q, cl, &diff);
721 if (old_mode != cl->cmode) {
722 if (old_mode != HTB_CAN_SEND)
723 htb_safe_rb_erase(&cl->pq_node, &q->hlevel[cl->level].wait_pq);
724 if (cl->cmode != HTB_CAN_SEND)
725 htb_add_to_wait_tree(q, cl, diff);
726 }
727
728 /* update basic stats except for leaves which are already updated */
729 if (cl->level)
730 bstats_update(&cl->bstats, skb);
731
732 cl = cl->parent;
733 }
734 }
735
736 /**
737 * htb_do_events - make mode changes to classes at the level
738 * @q: the priority event queue
739 * @level: which wait_pq in 'q->hlevel'
740 * @start: start jiffies
741 *
742 * Scans event queue for pending events and applies them. Returns time of
743 * next pending event (0 for no event in pq, q->now for too many events).
744 * Note: Applied are events whose have cl->pq_key <= q->now.
745 */
746 static s64 htb_do_events(struct htb_sched *q, const int level,
747 unsigned long start)
748 {
749 /* don't run for longer than 2 jiffies; 2 is used instead of
750 * 1 to simplify things when jiffy is going to be incremented
751 * too soon
752 */
753 unsigned long stop_at = start + 2;
754 struct rb_root *wait_pq = &q->hlevel[level].wait_pq;
755
756 while (time_before(jiffies, stop_at)) {
757 struct htb_class *cl;
758 s64 diff;
759 struct rb_node *p = rb_first(wait_pq);
760
761 if (!p)
762 return 0;
763
764 cl = rb_entry(p, struct htb_class, pq_node);
765 if (cl->pq_key > q->now)
766 return cl->pq_key;
767
768 htb_safe_rb_erase(p, wait_pq);
769 diff = min_t(s64, q->now - cl->t_c, cl->mbuffer);
770 htb_change_class_mode(q, cl, &diff);
771 if (cl->cmode != HTB_CAN_SEND)
772 htb_add_to_wait_tree(q, cl, diff);
773 }
774
775 /* too much load - let's continue after a break for scheduling */
776 if (!(q->warned & HTB_WARN_TOOMANYEVENTS)) {
777 pr_warn("htb: too many events!\n");
778 q->warned |= HTB_WARN_TOOMANYEVENTS;
779 }
780
781 return q->now;
782 }
783
784 /* Returns class->node+prio from id-tree where classe's id is >= id. NULL
785 * is no such one exists.
786 */
787 static struct rb_node *htb_id_find_next_upper(int prio, struct rb_node *n,
788 u32 id)
789 {
790 struct rb_node *r = NULL;
791 while (n) {
792 struct htb_class *cl =
793 rb_entry(n, struct htb_class, node[prio]);
794
795 if (id > cl->common.classid) {
796 n = n->rb_right;
797 } else if (id < cl->common.classid) {
798 r = n;
799 n = n->rb_left;
800 } else {
801 return n;
802 }
803 }
804 return r;
805 }
806
807 /**
808 * htb_lookup_leaf - returns next leaf class in DRR order
809 * @hprio: the current one
810 * @prio: which prio in class
811 *
812 * Find leaf where current feed pointers points to.
813 */
814 static struct htb_class *htb_lookup_leaf(struct htb_prio *hprio, const int prio)
815 {
816 int i;
817 struct {
818 struct rb_node *root;
819 struct rb_node **pptr;
820 u32 *pid;
821 } stk[TC_HTB_MAXDEPTH], *sp = stk;
822
823 BUG_ON(!hprio->row.rb_node);
824 sp->root = hprio->row.rb_node;
825 sp->pptr = &hprio->ptr;
826 sp->pid = &hprio->last_ptr_id;
827
828 for (i = 0; i < 65535; i++) {
829 if (!*sp->pptr && *sp->pid) {
830 /* ptr was invalidated but id is valid - try to recover
831 * the original or next ptr
832 */
833 *sp->pptr =
834 htb_id_find_next_upper(prio, sp->root, *sp->pid);
835 }
836 *sp->pid = 0; /* ptr is valid now so that remove this hint as it
837 * can become out of date quickly
838 */
839 if (!*sp->pptr) { /* we are at right end; rewind & go up */
840 *sp->pptr = sp->root;
841 while ((*sp->pptr)->rb_left)
842 *sp->pptr = (*sp->pptr)->rb_left;
843 if (sp > stk) {
844 sp--;
845 if (!*sp->pptr) {
846 WARN_ON(1);
847 return NULL;
848 }
849 htb_next_rb_node(sp->pptr);
850 }
851 } else {
852 struct htb_class *cl;
853 struct htb_prio *clp;
854
855 cl = rb_entry(*sp->pptr, struct htb_class, node[prio]);
856 if (!cl->level)
857 return cl;
858 clp = &cl->inner.clprio[prio];
859 (++sp)->root = clp->feed.rb_node;
860 sp->pptr = &clp->ptr;
861 sp->pid = &clp->last_ptr_id;
862 }
863 }
864 WARN_ON(1);
865 return NULL;
866 }
867
868 /* dequeues packet at given priority and level; call only if
869 * you are sure that there is active class at prio/level
870 */
871 static struct sk_buff *htb_dequeue_tree(struct htb_sched *q, const int prio,
872 const int level)
873 {
874 struct sk_buff *skb = NULL;
875 struct htb_class *cl, *start;
876 struct htb_level *hlevel = &q->hlevel[level];
877 struct htb_prio *hprio = &hlevel->hprio[prio];
878
879 /* look initial class up in the row */
880 start = cl = htb_lookup_leaf(hprio, prio);
881
882 do {
883 next:
884 if (unlikely(!cl))
885 return NULL;
886
887 /* class can be empty - it is unlikely but can be true if leaf
888 * qdisc drops packets in enqueue routine or if someone used
889 * graft operation on the leaf since last dequeue;
890 * simply deactivate and skip such class
891 */
892 if (unlikely(cl->leaf.q->q.qlen == 0)) {
893 struct htb_class *next;
894 htb_deactivate(q, cl);
895
896 /* row/level might become empty */
897 if ((q->row_mask[level] & (1 << prio)) == 0)
898 return NULL;
899
900 next = htb_lookup_leaf(hprio, prio);
901
902 if (cl == start) /* fix start if we just deleted it */
903 start = next;
904 cl = next;
905 goto next;
906 }
907
908 skb = cl->leaf.q->dequeue(cl->leaf.q);
909 if (likely(skb != NULL))
910 break;
911
912 qdisc_warn_nonwc("htb", cl->leaf.q);
913 htb_next_rb_node(level ? &cl->parent->inner.clprio[prio].ptr:
914 &q->hlevel[0].hprio[prio].ptr);
915 cl = htb_lookup_leaf(hprio, prio);
916
917 } while (cl != start);
918
919 if (likely(skb != NULL)) {
920 bstats_update(&cl->bstats, skb);
921 cl->leaf.deficit[level] -= qdisc_pkt_len(skb);
922 if (cl->leaf.deficit[level] < 0) {
923 cl->leaf.deficit[level] += cl->quantum;
924 htb_next_rb_node(level ? &cl->parent->inner.clprio[prio].ptr :
925 &q->hlevel[0].hprio[prio].ptr);
926 }
927 /* this used to be after charge_class but this constelation
928 * gives us slightly better performance
929 */
930 if (!cl->leaf.q->q.qlen)
931 htb_deactivate(q, cl);
932 htb_charge_class(q, cl, level, skb);
933 }
934 return skb;
935 }
936
937 static struct sk_buff *htb_dequeue(struct Qdisc *sch)
938 {
939 struct sk_buff *skb;
940 struct htb_sched *q = qdisc_priv(sch);
941 int level;
942 s64 next_event;
943 unsigned long start_at;
944
945 /* try to dequeue direct packets as high prio (!) to minimize cpu work */
946 skb = __qdisc_dequeue_head(&q->direct_queue);
947 if (skb != NULL) {
948 ok:
949 qdisc_bstats_update(sch, skb);
950 qdisc_qstats_backlog_dec(sch, skb);
951 sch->q.qlen--;
952 return skb;
953 }
954
955 if (!sch->q.qlen)
956 goto fin;
957 q->now = ktime_get_ns();
958 start_at = jiffies;
959
960 next_event = q->now + 5LLU * NSEC_PER_SEC;
961
962 for (level = 0; level < TC_HTB_MAXDEPTH; level++) {
963 /* common case optimization - skip event handler quickly */
964 int m;
965 s64 event = q->near_ev_cache[level];
966
967 if (q->now >= event) {
968 event = htb_do_events(q, level, start_at);
969 if (!event)
970 event = q->now + NSEC_PER_SEC;
971 q->near_ev_cache[level] = event;
972 }
973
974 if (next_event > event)
975 next_event = event;
976
977 m = ~q->row_mask[level];
978 while (m != (int)(-1)) {
979 int prio = ffz(m);
980
981 m |= 1 << prio;
982 skb = htb_dequeue_tree(q, prio, level);
983 if (likely(skb != NULL))
984 goto ok;
985 }
986 }
987 if (likely(next_event > q->now))
988 qdisc_watchdog_schedule_ns(&q->watchdog, next_event);
989 else
990 schedule_work(&q->work);
991 fin:
992 return skb;
993 }
994
995 /* reset all classes */
996 /* always caled under BH & queue lock */
997 static void htb_reset(struct Qdisc *sch)
998 {
999 struct htb_sched *q = qdisc_priv(sch);
1000 struct htb_class *cl;
1001 unsigned int i;
1002
1003 for (i = 0; i < q->clhash.hashsize; i++) {
1004 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
1005 if (cl->level)
1006 memset(&cl->inner, 0, sizeof(cl->inner));
1007 else {
1008 if (cl->leaf.q && !q->offload)
1009 qdisc_reset(cl->leaf.q);
1010 }
1011 cl->prio_activity = 0;
1012 cl->cmode = HTB_CAN_SEND;
1013 }
1014 }
1015 qdisc_watchdog_cancel(&q->watchdog);
1016 __qdisc_reset_queue(&q->direct_queue);
1017 memset(q->hlevel, 0, sizeof(q->hlevel));
1018 memset(q->row_mask, 0, sizeof(q->row_mask));
1019 }
1020
1021 static const struct nla_policy htb_policy[TCA_HTB_MAX + 1] = {
1022 [TCA_HTB_PARMS] = { .len = sizeof(struct tc_htb_opt) },
1023 [TCA_HTB_INIT] = { .len = sizeof(struct tc_htb_glob) },
1024 [TCA_HTB_CTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1025 [TCA_HTB_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE },
1026 [TCA_HTB_DIRECT_QLEN] = { .type = NLA_U32 },
1027 [TCA_HTB_RATE64] = { .type = NLA_U64 },
1028 [TCA_HTB_CEIL64] = { .type = NLA_U64 },
1029 [TCA_HTB_OFFLOAD] = { .type = NLA_FLAG },
1030 };
1031
1032 static void htb_work_func(struct work_struct *work)
1033 {
1034 struct htb_sched *q = container_of(work, struct htb_sched, work);
1035 struct Qdisc *sch = q->watchdog.qdisc;
1036
1037 rcu_read_lock();
1038 __netif_schedule(qdisc_root(sch));
1039 rcu_read_unlock();
1040 }
1041
1042 static int htb_offload(struct net_device *dev, struct tc_htb_qopt_offload *opt)
1043 {
1044 return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_QDISC_HTB, opt);
1045 }
1046
1047 static int htb_init(struct Qdisc *sch, struct nlattr *opt,
1048 struct netlink_ext_ack *extack)
1049 {
1050 struct net_device *dev = qdisc_dev(sch);
1051 struct tc_htb_qopt_offload offload_opt;
1052 struct htb_sched *q = qdisc_priv(sch);
1053 struct nlattr *tb[TCA_HTB_MAX + 1];
1054 struct tc_htb_glob *gopt;
1055 unsigned int ntx;
1056 bool offload;
1057 int err;
1058
1059 qdisc_watchdog_init(&q->watchdog, sch);
1060 INIT_WORK(&q->work, htb_work_func);
1061
1062 if (!opt)
1063 return -EINVAL;
1064
1065 err = tcf_block_get(&q->block, &q->filter_list, sch, extack);
1066 if (err)
1067 return err;
1068
1069 err = nla_parse_nested_deprecated(tb, TCA_HTB_MAX, opt, htb_policy,
1070 NULL);
1071 if (err < 0)
1072 return err;
1073
1074 if (!tb[TCA_HTB_INIT])
1075 return -EINVAL;
1076
1077 gopt = nla_data(tb[TCA_HTB_INIT]);
1078 if (gopt->version != HTB_VER >> 16)
1079 return -EINVAL;
1080
1081 offload = nla_get_flag(tb[TCA_HTB_OFFLOAD]);
1082
1083 if (offload) {
1084 if (sch->parent != TC_H_ROOT) {
1085 NL_SET_ERR_MSG(extack, "HTB must be the root qdisc to use offload");
1086 return -EOPNOTSUPP;
1087 }
1088
1089 if (!tc_can_offload(dev) || !dev->netdev_ops->ndo_setup_tc) {
1090 NL_SET_ERR_MSG(extack, "hw-tc-offload ethtool feature flag must be on");
1091 return -EOPNOTSUPP;
1092 }
1093
1094 q->num_direct_qdiscs = dev->real_num_tx_queues;
1095 q->direct_qdiscs = kcalloc(q->num_direct_qdiscs,
1096 sizeof(*q->direct_qdiscs),
1097 GFP_KERNEL);
1098 if (!q->direct_qdiscs)
1099 return -ENOMEM;
1100 }
1101
1102 err = qdisc_class_hash_init(&q->clhash);
1103 if (err < 0)
1104 return err;
1105
1106 if (tb[TCA_HTB_DIRECT_QLEN])
1107 q->direct_qlen = nla_get_u32(tb[TCA_HTB_DIRECT_QLEN]);
1108 else
1109 q->direct_qlen = qdisc_dev(sch)->tx_queue_len;
1110
1111 if ((q->rate2quantum = gopt->rate2quantum) < 1)
1112 q->rate2quantum = 1;
1113 q->defcls = gopt->defcls;
1114
1115 if (!offload)
1116 return 0;
1117
1118 for (ntx = 0; ntx < q->num_direct_qdiscs; ntx++) {
1119 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1120 struct Qdisc *qdisc;
1121
1122 qdisc = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1123 TC_H_MAKE(sch->handle, 0), extack);
1124 if (!qdisc) {
1125 return -ENOMEM;
1126 }
1127
1128 q->direct_qdiscs[ntx] = qdisc;
1129 qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1130 }
1131
1132 sch->flags |= TCQ_F_MQROOT;
1133
1134 offload_opt = (struct tc_htb_qopt_offload) {
1135 .command = TC_HTB_CREATE,
1136 .parent_classid = TC_H_MAJ(sch->handle) >> 16,
1137 .classid = TC_H_MIN(q->defcls),
1138 .extack = extack,
1139 };
1140 err = htb_offload(dev, &offload_opt);
1141 if (err)
1142 return err;
1143
1144 /* Defer this assignment, so that htb_destroy skips offload-related
1145 * parts (especially calling ndo_setup_tc) on errors.
1146 */
1147 q->offload = true;
1148
1149 return 0;
1150 }
1151
1152 static void htb_attach_offload(struct Qdisc *sch)
1153 {
1154 struct net_device *dev = qdisc_dev(sch);
1155 struct htb_sched *q = qdisc_priv(sch);
1156 unsigned int ntx;
1157
1158 for (ntx = 0; ntx < q->num_direct_qdiscs; ntx++) {
1159 struct Qdisc *old, *qdisc = q->direct_qdiscs[ntx];
1160
1161 old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
1162 qdisc_put(old);
1163 qdisc_hash_add(qdisc, false);
1164 }
1165 for (ntx = q->num_direct_qdiscs; ntx < dev->num_tx_queues; ntx++) {
1166 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1167 struct Qdisc *old = dev_graft_qdisc(dev_queue, NULL);
1168
1169 qdisc_put(old);
1170 }
1171
1172 kfree(q->direct_qdiscs);
1173 q->direct_qdiscs = NULL;
1174 }
1175
1176 static void htb_attach_software(struct Qdisc *sch)
1177 {
1178 struct net_device *dev = qdisc_dev(sch);
1179 unsigned int ntx;
1180
1181 /* Resemble qdisc_graft behavior. */
1182 for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
1183 struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
1184 struct Qdisc *old = dev_graft_qdisc(dev_queue, sch);
1185
1186 qdisc_refcount_inc(sch);
1187
1188 qdisc_put(old);
1189 }
1190 }
1191
1192 static void htb_attach(struct Qdisc *sch)
1193 {
1194 struct htb_sched *q = qdisc_priv(sch);
1195
1196 if (q->offload)
1197 htb_attach_offload(sch);
1198 else
1199 htb_attach_software(sch);
1200 }
1201
1202 static int htb_dump(struct Qdisc *sch, struct sk_buff *skb)
1203 {
1204 struct htb_sched *q = qdisc_priv(sch);
1205 struct nlattr *nest;
1206 struct tc_htb_glob gopt;
1207
1208 if (q->offload)
1209 sch->flags |= TCQ_F_OFFLOADED;
1210 else
1211 sch->flags &= ~TCQ_F_OFFLOADED;
1212
1213 sch->qstats.overlimits = q->overlimits;
1214 /* Its safe to not acquire qdisc lock. As we hold RTNL,
1215 * no change can happen on the qdisc parameters.
1216 */
1217
1218 gopt.direct_pkts = q->direct_pkts;
1219 gopt.version = HTB_VER;
1220 gopt.rate2quantum = q->rate2quantum;
1221 gopt.defcls = q->defcls;
1222 gopt.debug = 0;
1223
1224 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1225 if (nest == NULL)
1226 goto nla_put_failure;
1227 if (nla_put(skb, TCA_HTB_INIT, sizeof(gopt), &gopt) ||
1228 nla_put_u32(skb, TCA_HTB_DIRECT_QLEN, q->direct_qlen))
1229 goto nla_put_failure;
1230 if (q->offload && nla_put_flag(skb, TCA_HTB_OFFLOAD))
1231 goto nla_put_failure;
1232
1233 return nla_nest_end(skb, nest);
1234
1235 nla_put_failure:
1236 nla_nest_cancel(skb, nest);
1237 return -1;
1238 }
1239
1240 static int htb_dump_class(struct Qdisc *sch, unsigned long arg,
1241 struct sk_buff *skb, struct tcmsg *tcm)
1242 {
1243 struct htb_class *cl = (struct htb_class *)arg;
1244 struct htb_sched *q = qdisc_priv(sch);
1245 struct nlattr *nest;
1246 struct tc_htb_opt opt;
1247
1248 /* Its safe to not acquire qdisc lock. As we hold RTNL,
1249 * no change can happen on the class parameters.
1250 */
1251 tcm->tcm_parent = cl->parent ? cl->parent->common.classid : TC_H_ROOT;
1252 tcm->tcm_handle = cl->common.classid;
1253 if (!cl->level && cl->leaf.q)
1254 tcm->tcm_info = cl->leaf.q->handle;
1255
1256 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1257 if (nest == NULL)
1258 goto nla_put_failure;
1259
1260 memset(&opt, 0, sizeof(opt));
1261
1262 psched_ratecfg_getrate(&opt.rate, &cl->rate);
1263 opt.buffer = PSCHED_NS2TICKS(cl->buffer);
1264 psched_ratecfg_getrate(&opt.ceil, &cl->ceil);
1265 opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);
1266 opt.quantum = cl->quantum;
1267 opt.prio = cl->prio;
1268 opt.level = cl->level;
1269 if (nla_put(skb, TCA_HTB_PARMS, sizeof(opt), &opt))
1270 goto nla_put_failure;
1271 if (q->offload && nla_put_flag(skb, TCA_HTB_OFFLOAD))
1272 goto nla_put_failure;
1273 if ((cl->rate.rate_bytes_ps >= (1ULL << 32)) &&
1274 nla_put_u64_64bit(skb, TCA_HTB_RATE64, cl->rate.rate_bytes_ps,
1275 TCA_HTB_PAD))
1276 goto nla_put_failure;
1277 if ((cl->ceil.rate_bytes_ps >= (1ULL << 32)) &&
1278 nla_put_u64_64bit(skb, TCA_HTB_CEIL64, cl->ceil.rate_bytes_ps,
1279 TCA_HTB_PAD))
1280 goto nla_put_failure;
1281
1282 return nla_nest_end(skb, nest);
1283
1284 nla_put_failure:
1285 nla_nest_cancel(skb, nest);
1286 return -1;
1287 }
1288
1289 static void htb_offload_aggregate_stats(struct htb_sched *q,
1290 struct htb_class *cl)
1291 {
1292 u64 bytes = 0, packets = 0;
1293 struct htb_class *c;
1294 unsigned int i;
1295
1296 gnet_stats_basic_sync_init(&cl->bstats);
1297
1298 for (i = 0; i < q->clhash.hashsize; i++) {
1299 hlist_for_each_entry(c, &q->clhash.hash[i], common.hnode) {
1300 struct htb_class *p = c;
1301
1302 while (p && p->level < cl->level)
1303 p = p->parent;
1304
1305 if (p != cl)
1306 continue;
1307
1308 bytes += u64_stats_read(&c->bstats_bias.bytes);
1309 packets += u64_stats_read(&c->bstats_bias.packets);
1310 if (c->level == 0) {
1311 bytes += u64_stats_read(&c->leaf.q->bstats.bytes);
1312 packets += u64_stats_read(&c->leaf.q->bstats.packets);
1313 }
1314 }
1315 }
1316 _bstats_update(&cl->bstats, bytes, packets);
1317 }
1318
1319 static int
1320 htb_dump_class_stats(struct Qdisc *sch, unsigned long arg, struct gnet_dump *d)
1321 {
1322 struct htb_class *cl = (struct htb_class *)arg;
1323 struct htb_sched *q = qdisc_priv(sch);
1324 struct gnet_stats_queue qs = {
1325 .drops = cl->drops,
1326 .overlimits = cl->overlimits,
1327 };
1328 __u32 qlen = 0;
1329
1330 if (!cl->level && cl->leaf.q)
1331 qdisc_qstats_qlen_backlog(cl->leaf.q, &qlen, &qs.backlog);
1332
1333 cl->xstats.tokens = clamp_t(s64, PSCHED_NS2TICKS(cl->tokens),
1334 INT_MIN, INT_MAX);
1335 cl->xstats.ctokens = clamp_t(s64, PSCHED_NS2TICKS(cl->ctokens),
1336 INT_MIN, INT_MAX);
1337
1338 if (q->offload) {
1339 if (!cl->level) {
1340 if (cl->leaf.q)
1341 cl->bstats = cl->leaf.q->bstats;
1342 else
1343 gnet_stats_basic_sync_init(&cl->bstats);
1344 _bstats_update(&cl->bstats,
1345 u64_stats_read(&cl->bstats_bias.bytes),
1346 u64_stats_read(&cl->bstats_bias.packets));
1347 } else {
1348 htb_offload_aggregate_stats(q, cl);
1349 }
1350 }
1351
1352 if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
1353 gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1354 gnet_stats_copy_queue(d, NULL, &qs, qlen) < 0)
1355 return -1;
1356
1357 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats));
1358 }
1359
1360 static struct netdev_queue *
1361 htb_select_queue(struct Qdisc *sch, struct tcmsg *tcm)
1362 {
1363 struct net_device *dev = qdisc_dev(sch);
1364 struct tc_htb_qopt_offload offload_opt;
1365 struct htb_sched *q = qdisc_priv(sch);
1366 int err;
1367
1368 if (!q->offload)
1369 return sch->dev_queue;
1370
1371 offload_opt = (struct tc_htb_qopt_offload) {
1372 .command = TC_HTB_LEAF_QUERY_QUEUE,
1373 .classid = TC_H_MIN(tcm->tcm_parent),
1374 };
1375 err = htb_offload(dev, &offload_opt);
1376 if (err || offload_opt.qid >= dev->num_tx_queues)
1377 return NULL;
1378 return netdev_get_tx_queue(dev, offload_opt.qid);
1379 }
1380
1381 static struct Qdisc *
1382 htb_graft_helper(struct netdev_queue *dev_queue, struct Qdisc *new_q)
1383 {
1384 struct net_device *dev = dev_queue->dev;
1385 struct Qdisc *old_q;
1386
1387 if (dev->flags & IFF_UP)
1388 dev_deactivate(dev);
1389 old_q = dev_graft_qdisc(dev_queue, new_q);
1390 if (new_q)
1391 new_q->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
1392 if (dev->flags & IFF_UP)
1393 dev_activate(dev);
1394
1395 return old_q;
1396 }
1397
1398 static struct netdev_queue *htb_offload_get_queue(struct htb_class *cl)
1399 {
1400 struct netdev_queue *queue;
1401
1402 queue = cl->leaf.offload_queue;
1403 if (!(cl->leaf.q->flags & TCQ_F_BUILTIN))
1404 WARN_ON(cl->leaf.q->dev_queue != queue);
1405
1406 return queue;
1407 }
1408
1409 static void htb_offload_move_qdisc(struct Qdisc *sch, struct htb_class *cl_old,
1410 struct htb_class *cl_new, bool destroying)
1411 {
1412 struct netdev_queue *queue_old, *queue_new;
1413 struct net_device *dev = qdisc_dev(sch);
1414
1415 queue_old = htb_offload_get_queue(cl_old);
1416 queue_new = htb_offload_get_queue(cl_new);
1417
1418 if (!destroying) {
1419 struct Qdisc *qdisc;
1420
1421 if (dev->flags & IFF_UP)
1422 dev_deactivate(dev);
1423 qdisc = dev_graft_qdisc(queue_old, NULL);
1424 WARN_ON(qdisc != cl_old->leaf.q);
1425 }
1426
1427 if (!(cl_old->leaf.q->flags & TCQ_F_BUILTIN))
1428 cl_old->leaf.q->dev_queue = queue_new;
1429 cl_old->leaf.offload_queue = queue_new;
1430
1431 if (!destroying) {
1432 struct Qdisc *qdisc;
1433
1434 qdisc = dev_graft_qdisc(queue_new, cl_old->leaf.q);
1435 if (dev->flags & IFF_UP)
1436 dev_activate(dev);
1437 WARN_ON(!(qdisc->flags & TCQ_F_BUILTIN));
1438 }
1439 }
1440
1441 static int htb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1442 struct Qdisc **old, struct netlink_ext_ack *extack)
1443 {
1444 struct netdev_queue *dev_queue = sch->dev_queue;
1445 struct htb_class *cl = (struct htb_class *)arg;
1446 struct htb_sched *q = qdisc_priv(sch);
1447 struct Qdisc *old_q;
1448
1449 if (cl->level)
1450 return -EINVAL;
1451
1452 if (q->offload)
1453 dev_queue = htb_offload_get_queue(cl);
1454
1455 if (!new) {
1456 new = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1457 cl->common.classid, extack);
1458 if (!new)
1459 return -ENOBUFS;
1460 }
1461
1462 if (q->offload) {
1463 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1464 qdisc_refcount_inc(new);
1465 old_q = htb_graft_helper(dev_queue, new);
1466 }
1467
1468 *old = qdisc_replace(sch, new, &cl->leaf.q);
1469
1470 if (q->offload) {
1471 WARN_ON(old_q != *old);
1472 qdisc_put(old_q);
1473 }
1474
1475 return 0;
1476 }
1477
1478 static struct Qdisc *htb_leaf(struct Qdisc *sch, unsigned long arg)
1479 {
1480 struct htb_class *cl = (struct htb_class *)arg;
1481 return !cl->level ? cl->leaf.q : NULL;
1482 }
1483
1484 static void htb_qlen_notify(struct Qdisc *sch, unsigned long arg)
1485 {
1486 struct htb_class *cl = (struct htb_class *)arg;
1487
1488 htb_deactivate(qdisc_priv(sch), cl);
1489 }
1490
1491 static inline int htb_parent_last_child(struct htb_class *cl)
1492 {
1493 if (!cl->parent)
1494 /* the root class */
1495 return 0;
1496 if (cl->parent->children > 1)
1497 /* not the last child */
1498 return 0;
1499 return 1;
1500 }
1501
1502 static void htb_parent_to_leaf(struct Qdisc *sch, struct htb_class *cl,
1503 struct Qdisc *new_q)
1504 {
1505 struct htb_sched *q = qdisc_priv(sch);
1506 struct htb_class *parent = cl->parent;
1507
1508 WARN_ON(cl->level || !cl->leaf.q || cl->prio_activity);
1509
1510 if (parent->cmode != HTB_CAN_SEND)
1511 htb_safe_rb_erase(&parent->pq_node,
1512 &q->hlevel[parent->level].wait_pq);
1513
1514 parent->level = 0;
1515 memset(&parent->inner, 0, sizeof(parent->inner));
1516 parent->leaf.q = new_q ? new_q : &noop_qdisc;
1517 parent->tokens = parent->buffer;
1518 parent->ctokens = parent->cbuffer;
1519 parent->t_c = ktime_get_ns();
1520 parent->cmode = HTB_CAN_SEND;
1521 if (q->offload)
1522 parent->leaf.offload_queue = cl->leaf.offload_queue;
1523 }
1524
1525 static void htb_parent_to_leaf_offload(struct Qdisc *sch,
1526 struct netdev_queue *dev_queue,
1527 struct Qdisc *new_q)
1528 {
1529 struct Qdisc *old_q;
1530
1531 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1532 if (new_q)
1533 qdisc_refcount_inc(new_q);
1534 old_q = htb_graft_helper(dev_queue, new_q);
1535 WARN_ON(!(old_q->flags & TCQ_F_BUILTIN));
1536 }
1537
1538 static int htb_destroy_class_offload(struct Qdisc *sch, struct htb_class *cl,
1539 bool last_child, bool destroying,
1540 struct netlink_ext_ack *extack)
1541 {
1542 struct tc_htb_qopt_offload offload_opt;
1543 struct netdev_queue *dev_queue;
1544 struct Qdisc *q = cl->leaf.q;
1545 struct Qdisc *old;
1546 int err;
1547
1548 if (cl->level)
1549 return -EINVAL;
1550
1551 WARN_ON(!q);
1552 dev_queue = htb_offload_get_queue(cl);
1553 /* When destroying, caller qdisc_graft grafts the new qdisc and invokes
1554 * qdisc_put for the qdisc being destroyed. htb_destroy_class_offload
1555 * does not need to graft or qdisc_put the qdisc being destroyed.
1556 */
1557 if (!destroying) {
1558 old = htb_graft_helper(dev_queue, NULL);
1559 /* Last qdisc grafted should be the same as cl->leaf.q when
1560 * calling htb_delete.
1561 */
1562 WARN_ON(old != q);
1563 }
1564
1565 if (cl->parent) {
1566 _bstats_update(&cl->parent->bstats_bias,
1567 u64_stats_read(&q->bstats.bytes),
1568 u64_stats_read(&q->bstats.packets));
1569 }
1570
1571 offload_opt = (struct tc_htb_qopt_offload) {
1572 .command = !last_child ? TC_HTB_LEAF_DEL :
1573 destroying ? TC_HTB_LEAF_DEL_LAST_FORCE :
1574 TC_HTB_LEAF_DEL_LAST,
1575 .classid = cl->common.classid,
1576 .extack = extack,
1577 };
1578 err = htb_offload(qdisc_dev(sch), &offload_opt);
1579
1580 if (!destroying) {
1581 if (!err)
1582 qdisc_put(old);
1583 else
1584 htb_graft_helper(dev_queue, old);
1585 }
1586
1587 if (last_child)
1588 return err;
1589
1590 if (!err && offload_opt.classid != TC_H_MIN(cl->common.classid)) {
1591 u32 classid = TC_H_MAJ(sch->handle) |
1592 TC_H_MIN(offload_opt.classid);
1593 struct htb_class *moved_cl = htb_find(classid, sch);
1594
1595 htb_offload_move_qdisc(sch, moved_cl, cl, destroying);
1596 }
1597
1598 return err;
1599 }
1600
1601 static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
1602 {
1603 if (!cl->level) {
1604 WARN_ON(!cl->leaf.q);
1605 qdisc_put(cl->leaf.q);
1606 }
1607 gen_kill_estimator(&cl->rate_est);
1608 tcf_block_put(cl->block);
1609 kfree(cl);
1610 }
1611
1612 static void htb_destroy(struct Qdisc *sch)
1613 {
1614 struct net_device *dev = qdisc_dev(sch);
1615 struct tc_htb_qopt_offload offload_opt;
1616 struct htb_sched *q = qdisc_priv(sch);
1617 struct hlist_node *next;
1618 bool nonempty, changed;
1619 struct htb_class *cl;
1620 unsigned int i;
1621
1622 cancel_work_sync(&q->work);
1623 qdisc_watchdog_cancel(&q->watchdog);
1624 /* This line used to be after htb_destroy_class call below
1625 * and surprisingly it worked in 2.4. But it must precede it
1626 * because filter need its target class alive to be able to call
1627 * unbind_filter on it (without Oops).
1628 */
1629 tcf_block_put(q->block);
1630
1631 for (i = 0; i < q->clhash.hashsize; i++) {
1632 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
1633 tcf_block_put(cl->block);
1634 cl->block = NULL;
1635 }
1636 }
1637
1638 do {
1639 nonempty = false;
1640 changed = false;
1641 for (i = 0; i < q->clhash.hashsize; i++) {
1642 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1643 common.hnode) {
1644 bool last_child;
1645
1646 if (!q->offload) {
1647 htb_destroy_class(sch, cl);
1648 continue;
1649 }
1650
1651 nonempty = true;
1652
1653 if (cl->level)
1654 continue;
1655
1656 changed = true;
1657
1658 last_child = htb_parent_last_child(cl);
1659 htb_destroy_class_offload(sch, cl, last_child,
1660 true, NULL);
1661 qdisc_class_hash_remove(&q->clhash,
1662 &cl->common);
1663 if (cl->parent)
1664 cl->parent->children--;
1665 if (last_child)
1666 htb_parent_to_leaf(sch, cl, NULL);
1667 htb_destroy_class(sch, cl);
1668 }
1669 }
1670 } while (changed);
1671 WARN_ON(nonempty);
1672
1673 qdisc_class_hash_destroy(&q->clhash);
1674 __qdisc_reset_queue(&q->direct_queue);
1675
1676 if (q->offload) {
1677 offload_opt = (struct tc_htb_qopt_offload) {
1678 .command = TC_HTB_DESTROY,
1679 };
1680 htb_offload(dev, &offload_opt);
1681 }
1682
1683 if (!q->direct_qdiscs)
1684 return;
1685 for (i = 0; i < q->num_direct_qdiscs && q->direct_qdiscs[i]; i++)
1686 qdisc_put(q->direct_qdiscs[i]);
1687 kfree(q->direct_qdiscs);
1688 }
1689
1690 static int htb_delete(struct Qdisc *sch, unsigned long arg,
1691 struct netlink_ext_ack *extack)
1692 {
1693 struct htb_sched *q = qdisc_priv(sch);
1694 struct htb_class *cl = (struct htb_class *)arg;
1695 struct Qdisc *new_q = NULL;
1696 int last_child = 0;
1697 int err;
1698
1699 /* TODO: why don't allow to delete subtree ? references ? does
1700 * tc subsys guarantee us that in htb_destroy it holds no class
1701 * refs so that we can remove children safely there ?
1702 */
1703 if (cl->children || qdisc_class_in_use(&cl->common)) {
1704 NL_SET_ERR_MSG(extack, "HTB class in use");
1705 return -EBUSY;
1706 }
1707
1708 if (!cl->level && htb_parent_last_child(cl))
1709 last_child = 1;
1710
1711 if (q->offload) {
1712 err = htb_destroy_class_offload(sch, cl, last_child, false,
1713 extack);
1714 if (err)
1715 return err;
1716 }
1717
1718 if (last_child) {
1719 struct netdev_queue *dev_queue = sch->dev_queue;
1720
1721 if (q->offload)
1722 dev_queue = htb_offload_get_queue(cl);
1723
1724 new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1725 cl->parent->common.classid,
1726 NULL);
1727 if (q->offload)
1728 htb_parent_to_leaf_offload(sch, dev_queue, new_q);
1729 }
1730
1731 sch_tree_lock(sch);
1732
1733 if (!cl->level)
1734 qdisc_purge_queue(cl->leaf.q);
1735
1736 /* delete from hash and active; remainder in destroy_class */
1737 qdisc_class_hash_remove(&q->clhash, &cl->common);
1738 if (cl->parent)
1739 cl->parent->children--;
1740
1741 if (cl->prio_activity)
1742 htb_deactivate(q, cl);
1743
1744 if (cl->cmode != HTB_CAN_SEND)
1745 htb_safe_rb_erase(&cl->pq_node,
1746 &q->hlevel[cl->level].wait_pq);
1747
1748 if (last_child)
1749 htb_parent_to_leaf(sch, cl, new_q);
1750
1751 sch_tree_unlock(sch);
1752
1753 htb_destroy_class(sch, cl);
1754 return 0;
1755 }
1756
1757 static int htb_change_class(struct Qdisc *sch, u32 classid,
1758 u32 parentid, struct nlattr **tca,
1759 unsigned long *arg, struct netlink_ext_ack *extack)
1760 {
1761 int err = -EINVAL;
1762 struct htb_sched *q = qdisc_priv(sch);
1763 struct htb_class *cl = (struct htb_class *)*arg, *parent;
1764 struct tc_htb_qopt_offload offload_opt;
1765 struct nlattr *opt = tca[TCA_OPTIONS];
1766 struct nlattr *tb[TCA_HTB_MAX + 1];
1767 struct Qdisc *parent_qdisc = NULL;
1768 struct netdev_queue *dev_queue;
1769 struct tc_htb_opt *hopt;
1770 u64 rate64, ceil64;
1771 int warn = 0;
1772
1773 /* extract all subattrs from opt attr */
1774 if (!opt)
1775 goto failure;
1776
1777 err = nla_parse_nested_deprecated(tb, TCA_HTB_MAX, opt, htb_policy,
1778 extack);
1779 if (err < 0)
1780 goto failure;
1781
1782 err = -EINVAL;
1783 if (tb[TCA_HTB_PARMS] == NULL)
1784 goto failure;
1785
1786 parent = parentid == TC_H_ROOT ? NULL : htb_find(parentid, sch);
1787
1788 hopt = nla_data(tb[TCA_HTB_PARMS]);
1789 if (!hopt->rate.rate || !hopt->ceil.rate)
1790 goto failure;
1791
1792 if (q->offload) {
1793 /* Options not supported by the offload. */
1794 if (hopt->rate.overhead || hopt->ceil.overhead) {
1795 NL_SET_ERR_MSG(extack, "HTB offload doesn't support the overhead parameter");
1796 goto failure;
1797 }
1798 if (hopt->rate.mpu || hopt->ceil.mpu) {
1799 NL_SET_ERR_MSG(extack, "HTB offload doesn't support the mpu parameter");
1800 goto failure;
1801 }
1802 }
1803
1804 /* Keeping backward compatible with rate_table based iproute2 tc */
1805 if (hopt->rate.linklayer == TC_LINKLAYER_UNAWARE)
1806 qdisc_put_rtab(qdisc_get_rtab(&hopt->rate, tb[TCA_HTB_RTAB],
1807 NULL));
1808
1809 if (hopt->ceil.linklayer == TC_LINKLAYER_UNAWARE)
1810 qdisc_put_rtab(qdisc_get_rtab(&hopt->ceil, tb[TCA_HTB_CTAB],
1811 NULL));
1812
1813 rate64 = tb[TCA_HTB_RATE64] ? nla_get_u64(tb[TCA_HTB_RATE64]) : 0;
1814 ceil64 = tb[TCA_HTB_CEIL64] ? nla_get_u64(tb[TCA_HTB_CEIL64]) : 0;
1815
1816 if (!cl) { /* new class */
1817 struct net_device *dev = qdisc_dev(sch);
1818 struct Qdisc *new_q, *old_q;
1819 int prio;
1820 struct {
1821 struct nlattr nla;
1822 struct gnet_estimator opt;
1823 } est = {
1824 .nla = {
1825 .nla_len = nla_attr_size(sizeof(est.opt)),
1826 .nla_type = TCA_RATE,
1827 },
1828 .opt = {
1829 /* 4s interval, 16s averaging constant */
1830 .interval = 2,
1831 .ewma_log = 2,
1832 },
1833 };
1834
1835 /* check for valid classid */
1836 if (!classid || TC_H_MAJ(classid ^ sch->handle) ||
1837 htb_find(classid, sch))
1838 goto failure;
1839
1840 /* check maximal depth */
1841 if (parent && parent->parent && parent->parent->level < 2) {
1842 NL_SET_ERR_MSG_MOD(extack, "tree is too deep");
1843 goto failure;
1844 }
1845 err = -ENOBUFS;
1846 cl = kzalloc(sizeof(*cl), GFP_KERNEL);
1847 if (!cl)
1848 goto failure;
1849
1850 gnet_stats_basic_sync_init(&cl->bstats);
1851 gnet_stats_basic_sync_init(&cl->bstats_bias);
1852
1853 err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1854 if (err) {
1855 kfree(cl);
1856 goto failure;
1857 }
1858 if (htb_rate_est || tca[TCA_RATE]) {
1859 err = gen_new_estimator(&cl->bstats, NULL,
1860 &cl->rate_est,
1861 NULL,
1862 true,
1863 tca[TCA_RATE] ? : &est.nla);
1864 if (err)
1865 goto err_block_put;
1866 }
1867
1868 cl->children = 0;
1869 RB_CLEAR_NODE(&cl->pq_node);
1870
1871 for (prio = 0; prio < TC_HTB_NUMPRIO; prio++)
1872 RB_CLEAR_NODE(&cl->node[prio]);
1873
1874 cl->common.classid = classid;
1875
1876 /* Make sure nothing interrupts us in between of two
1877 * ndo_setup_tc calls.
1878 */
1879 ASSERT_RTNL();
1880
1881 /* create leaf qdisc early because it uses kmalloc(GFP_KERNEL)
1882 * so that can't be used inside of sch_tree_lock
1883 * -- thanks to Karlis Peisenieks
1884 */
1885 if (!q->offload) {
1886 dev_queue = sch->dev_queue;
1887 } else if (!(parent && !parent->level)) {
1888 /* Assign a dev_queue to this classid. */
1889 offload_opt = (struct tc_htb_qopt_offload) {
1890 .command = TC_HTB_LEAF_ALLOC_QUEUE,
1891 .classid = cl->common.classid,
1892 .parent_classid = parent ?
1893 TC_H_MIN(parent->common.classid) :
1894 TC_HTB_CLASSID_ROOT,
1895 .rate = max_t(u64, hopt->rate.rate, rate64),
1896 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1897 .prio = hopt->prio,
1898 .quantum = hopt->quantum,
1899 .extack = extack,
1900 };
1901 err = htb_offload(dev, &offload_opt);
1902 if (err) {
1903 NL_SET_ERR_MSG_WEAK(extack,
1904 "Failed to offload TC_HTB_LEAF_ALLOC_QUEUE");
1905 goto err_kill_estimator;
1906 }
1907 dev_queue = netdev_get_tx_queue(dev, offload_opt.qid);
1908 } else { /* First child. */
1909 dev_queue = htb_offload_get_queue(parent);
1910 old_q = htb_graft_helper(dev_queue, NULL);
1911 WARN_ON(old_q != parent->leaf.q);
1912 offload_opt = (struct tc_htb_qopt_offload) {
1913 .command = TC_HTB_LEAF_TO_INNER,
1914 .classid = cl->common.classid,
1915 .parent_classid =
1916 TC_H_MIN(parent->common.classid),
1917 .rate = max_t(u64, hopt->rate.rate, rate64),
1918 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
1919 .prio = hopt->prio,
1920 .quantum = hopt->quantum,
1921 .extack = extack,
1922 };
1923 err = htb_offload(dev, &offload_opt);
1924 if (err) {
1925 NL_SET_ERR_MSG_WEAK(extack,
1926 "Failed to offload TC_HTB_LEAF_TO_INNER");
1927 htb_graft_helper(dev_queue, old_q);
1928 goto err_kill_estimator;
1929 }
1930 _bstats_update(&parent->bstats_bias,
1931 u64_stats_read(&old_q->bstats.bytes),
1932 u64_stats_read(&old_q->bstats.packets));
1933 qdisc_put(old_q);
1934 }
1935 new_q = qdisc_create_dflt(dev_queue, &pfifo_qdisc_ops,
1936 classid, NULL);
1937 if (q->offload) {
1938 /* One ref for cl->leaf.q, the other for dev_queue->qdisc. */
1939 if (new_q)
1940 qdisc_refcount_inc(new_q);
1941 old_q = htb_graft_helper(dev_queue, new_q);
1942 /* No qdisc_put needed. */
1943 WARN_ON(!(old_q->flags & TCQ_F_BUILTIN));
1944 }
1945 sch_tree_lock(sch);
1946 if (parent && !parent->level) {
1947 /* turn parent into inner node */
1948 qdisc_purge_queue(parent->leaf.q);
1949 parent_qdisc = parent->leaf.q;
1950 if (parent->prio_activity)
1951 htb_deactivate(q, parent);
1952
1953 /* remove from evt list because of level change */
1954 if (parent->cmode != HTB_CAN_SEND) {
1955 htb_safe_rb_erase(&parent->pq_node, &q->hlevel[0].wait_pq);
1956 parent->cmode = HTB_CAN_SEND;
1957 }
1958 parent->level = (parent->parent ? parent->parent->level
1959 : TC_HTB_MAXDEPTH) - 1;
1960 memset(&parent->inner, 0, sizeof(parent->inner));
1961 }
1962
1963 /* leaf (we) needs elementary qdisc */
1964 cl->leaf.q = new_q ? new_q : &noop_qdisc;
1965 if (q->offload)
1966 cl->leaf.offload_queue = dev_queue;
1967
1968 cl->parent = parent;
1969
1970 /* set class to be in HTB_CAN_SEND state */
1971 cl->tokens = PSCHED_TICKS2NS(hopt->buffer);
1972 cl->ctokens = PSCHED_TICKS2NS(hopt->cbuffer);
1973 cl->mbuffer = 60ULL * NSEC_PER_SEC; /* 1min */
1974 cl->t_c = ktime_get_ns();
1975 cl->cmode = HTB_CAN_SEND;
1976
1977 /* attach to the hash list and parent's family */
1978 qdisc_class_hash_insert(&q->clhash, &cl->common);
1979 if (parent)
1980 parent->children++;
1981 if (cl->leaf.q != &noop_qdisc)
1982 qdisc_hash_add(cl->leaf.q, true);
1983 } else {
1984 if (tca[TCA_RATE]) {
1985 err = gen_replace_estimator(&cl->bstats, NULL,
1986 &cl->rate_est,
1987 NULL,
1988 true,
1989 tca[TCA_RATE]);
1990 if (err)
1991 return err;
1992 }
1993
1994 if (q->offload) {
1995 struct net_device *dev = qdisc_dev(sch);
1996
1997 offload_opt = (struct tc_htb_qopt_offload) {
1998 .command = TC_HTB_NODE_MODIFY,
1999 .classid = cl->common.classid,
2000 .rate = max_t(u64, hopt->rate.rate, rate64),
2001 .ceil = max_t(u64, hopt->ceil.rate, ceil64),
2002 .prio = hopt->prio,
2003 .quantum = hopt->quantum,
2004 .extack = extack,
2005 };
2006 err = htb_offload(dev, &offload_opt);
2007 if (err)
2008 /* Estimator was replaced, and rollback may fail
2009 * as well, so we don't try to recover it, and
2010 * the estimator won't work property with the
2011 * offload anyway, because bstats are updated
2012 * only when the stats are queried.
2013 */
2014 return err;
2015 }
2016
2017 sch_tree_lock(sch);
2018 }
2019
2020 psched_ratecfg_precompute(&cl->rate, &hopt->rate, rate64);
2021 psched_ratecfg_precompute(&cl->ceil, &hopt->ceil, ceil64);
2022
2023 /* it used to be a nasty bug here, we have to check that node
2024 * is really leaf before changing cl->leaf !
2025 */
2026 if (!cl->level) {
2027 u64 quantum = cl->rate.rate_bytes_ps;
2028
2029 do_div(quantum, q->rate2quantum);
2030 cl->quantum = min_t(u64, quantum, INT_MAX);
2031
2032 if (!hopt->quantum && cl->quantum < 1000) {
2033 warn = -1;
2034 cl->quantum = 1000;
2035 }
2036 if (!hopt->quantum && cl->quantum > 200000) {
2037 warn = 1;
2038 cl->quantum = 200000;
2039 }
2040 if (hopt->quantum)
2041 cl->quantum = hopt->quantum;
2042 if ((cl->prio = hopt->prio) >= TC_HTB_NUMPRIO)
2043 cl->prio = TC_HTB_NUMPRIO - 1;
2044 }
2045
2046 cl->buffer = PSCHED_TICKS2NS(hopt->buffer);
2047 cl->cbuffer = PSCHED_TICKS2NS(hopt->cbuffer);
2048
2049 sch_tree_unlock(sch);
2050 qdisc_put(parent_qdisc);
2051
2052 if (warn)
2053 NL_SET_ERR_MSG_FMT_MOD(extack,
2054 "quantum of class %X is %s. Consider r2q change.",
2055 cl->common.classid, (warn == -1 ? "small" : "big"));
2056
2057 qdisc_class_hash_grow(sch, &q->clhash);
2058
2059 *arg = (unsigned long)cl;
2060 return 0;
2061
2062 err_kill_estimator:
2063 gen_kill_estimator(&cl->rate_est);
2064 err_block_put:
2065 tcf_block_put(cl->block);
2066 kfree(cl);
2067 failure:
2068 return err;
2069 }
2070
2071 static struct tcf_block *htb_tcf_block(struct Qdisc *sch, unsigned long arg,
2072 struct netlink_ext_ack *extack)
2073 {
2074 struct htb_sched *q = qdisc_priv(sch);
2075 struct htb_class *cl = (struct htb_class *)arg;
2076
2077 return cl ? cl->block : q->block;
2078 }
2079
2080 static unsigned long htb_bind_filter(struct Qdisc *sch, unsigned long parent,
2081 u32 classid)
2082 {
2083 struct htb_class *cl = htb_find(classid, sch);
2084
2085 /*if (cl && !cl->level) return 0;
2086 * The line above used to be there to prevent attaching filters to
2087 * leaves. But at least tc_index filter uses this just to get class
2088 * for other reasons so that we have to allow for it.
2089 * ----
2090 * 19.6.2002 As Werner explained it is ok - bind filter is just
2091 * another way to "lock" the class - unlike "get" this lock can
2092 * be broken by class during destroy IIUC.
2093 */
2094 if (cl)
2095 qdisc_class_get(&cl->common);
2096 return (unsigned long)cl;
2097 }
2098
2099 static void htb_unbind_filter(struct Qdisc *sch, unsigned long arg)
2100 {
2101 struct htb_class *cl = (struct htb_class *)arg;
2102
2103 qdisc_class_put(&cl->common);
2104 }
2105
2106 static void htb_walk(struct Qdisc *sch, struct qdisc_walker *arg)
2107 {
2108 struct htb_sched *q = qdisc_priv(sch);
2109 struct htb_class *cl;
2110 unsigned int i;
2111
2112 if (arg->stop)
2113 return;
2114
2115 for (i = 0; i < q->clhash.hashsize; i++) {
2116 hlist_for_each_entry(cl, &q->clhash.hash[i], common.hnode) {
2117 if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
2118 return;
2119 }
2120 }
2121 }
2122
2123 static const struct Qdisc_class_ops htb_class_ops = {
2124 .select_queue = htb_select_queue,
2125 .graft = htb_graft,
2126 .leaf = htb_leaf,
2127 .qlen_notify = htb_qlen_notify,
2128 .find = htb_search,
2129 .change = htb_change_class,
2130 .delete = htb_delete,
2131 .walk = htb_walk,
2132 .tcf_block = htb_tcf_block,
2133 .bind_tcf = htb_bind_filter,
2134 .unbind_tcf = htb_unbind_filter,
2135 .dump = htb_dump_class,
2136 .dump_stats = htb_dump_class_stats,
2137 };
2138
2139 static struct Qdisc_ops htb_qdisc_ops __read_mostly = {
2140 .cl_ops = &htb_class_ops,
2141 .id = "htb",
2142 .priv_size = sizeof(struct htb_sched),
2143 .enqueue = htb_enqueue,
2144 .dequeue = htb_dequeue,
2145 .peek = qdisc_peek_dequeued,
2146 .init = htb_init,
2147 .attach = htb_attach,
2148 .reset = htb_reset,
2149 .destroy = htb_destroy,
2150 .dump = htb_dump,
2151 .owner = THIS_MODULE,
2152 };
2153 MODULE_ALIAS_NET_SCH("htb");
2154
2155 static int __init htb_module_init(void)
2156 {
2157 return register_qdisc(&htb_qdisc_ops);
2158 }
2159 static void __exit htb_module_exit(void)
2160 {
2161 unregister_qdisc(&htb_qdisc_ops);
2162 }
2163
2164 module_init(htb_module_init)
2165 module_exit(htb_module_exit)
2166 MODULE_LICENSE("GPL");
2167 MODULE_DESCRIPTION("Hierarchical Token Bucket scheduler");
2168
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