xref: /freebsd/sys/net/altq/altq_rmclass.c (revision 0957b409)
1 /*-
2  * Copyright (c) 1991-1997 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *      This product includes software developed by the Network Research
16  *      Group at Lawrence Berkeley Laboratory.
17  * 4. Neither the name of the University nor of the Laboratory may be used
18  *    to endorse or promote products derived from this software without
19  *    specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * LBL code modified by speer@eng.sun.com, May 1977.
34  * For questions and/or comments, please send mail to cbq@ee.lbl.gov
35  *
36  * @(#)rm_class.c  1.48     97/12/05 SMI
37  * $KAME: altq_rmclass.c,v 1.19 2005/04/13 03:44:25 suz Exp $
38  * $FreeBSD$
39  */
40 #include "opt_altq.h"
41 #include "opt_inet.h"
42 #include "opt_inet6.h"
43 #ifdef ALTQ_CBQ	/* cbq is enabled by ALTQ_CBQ option in opt_altq.h */
44 
45 #include <sys/param.h>
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/socket.h>
49 #include <sys/systm.h>
50 #include <sys/errno.h>
51 #include <sys/time.h>
52 
53 #include <net/if.h>
54 #include <net/if_var.h>
55 
56 #include <net/altq/if_altq.h>
57 #include <net/altq/altq.h>
58 #include <net/altq/altq_codel.h>
59 #include <net/altq/altq_rmclass.h>
60 #include <net/altq/altq_rmclass_debug.h>
61 #include <net/altq/altq_red.h>
62 #include <net/altq/altq_rio.h>
63 
64 /*
65  * Local Macros
66  */
67 
68 #define	reset_cutoff(ifd)	{ ifd->cutoff_ = RM_MAXDEPTH; }
69 
70 /*
71  * Local routines.
72  */
73 
74 static int	rmc_satisfied(struct rm_class *, struct timeval *);
75 static void	rmc_wrr_set_weights(struct rm_ifdat *);
76 static void	rmc_depth_compute(struct rm_class *);
77 static void	rmc_depth_recompute(rm_class_t *);
78 
79 static mbuf_t	*_rmc_wrr_dequeue_next(struct rm_ifdat *, int);
80 static mbuf_t	*_rmc_prr_dequeue_next(struct rm_ifdat *, int);
81 
82 static int	_rmc_addq(rm_class_t *, mbuf_t *);
83 static void	_rmc_dropq(rm_class_t *);
84 static mbuf_t	*_rmc_getq(rm_class_t *);
85 static mbuf_t	*_rmc_pollq(rm_class_t *);
86 
87 static int	rmc_under_limit(struct rm_class *, struct timeval *);
88 static void	rmc_tl_satisfied(struct rm_ifdat *, struct timeval *);
89 static void	rmc_drop_action(struct rm_class *);
90 static void	rmc_restart(struct rm_class *);
91 static void	rmc_root_overlimit(struct rm_class *, struct rm_class *);
92 
93 #define	BORROW_OFFTIME
94 /*
95  * BORROW_OFFTIME (experimental):
96  * borrow the offtime of the class borrowing from.
97  * the reason is that when its own offtime is set, the class is unable
98  * to borrow much, especially when cutoff is taking effect.
99  * but when the borrowed class is overloaded (advidle is close to minidle),
100  * use the borrowing class's offtime to avoid overload.
101  */
102 #define	ADJUST_CUTOFF
103 /*
104  * ADJUST_CUTOFF (experimental):
105  * if no underlimit class is found due to cutoff, increase cutoff and
106  * retry the scheduling loop.
107  * also, don't invoke delay_actions while cutoff is taking effect,
108  * since a sleeping class won't have a chance to be scheduled in the
109  * next loop.
110  *
111  * now heuristics for setting the top-level variable (cutoff_) becomes:
112  *	1. if a packet arrives for a not-overlimit class, set cutoff
113  *	   to the depth of the class.
114  *	2. if cutoff is i, and a packet arrives for an overlimit class
115  *	   with an underlimit ancestor at a lower level than i (say j),
116  *	   then set cutoff to j.
117  *	3. at scheduling a packet, if there is no underlimit class
118  *	   due to the current cutoff level, increase cutoff by 1 and
119  *	   then try to schedule again.
120  */
121 
122 /*
123  * rm_class_t *
124  * rmc_newclass(...) - Create a new resource management class at priority
125  * 'pri' on the interface given by 'ifd'.
126  *
127  * nsecPerByte  is the data rate of the interface in nanoseconds/byte.
128  *              E.g., 800 for a 10Mb/s ethernet.  If the class gets less
129  *              than 100% of the bandwidth, this number should be the
130  *              'effective' rate for the class.  Let f be the
131  *              bandwidth fraction allocated to this class, and let
132  *              nsPerByte be the data rate of the output link in
133  *              nanoseconds/byte.  Then nsecPerByte is set to
134  *              nsPerByte / f.  E.g., 1600 (= 800 / .5)
135  *              for a class that gets 50% of an ethernet's bandwidth.
136  *
137  * action       the routine to call when the class is over limit.
138  *
139  * maxq         max allowable queue size for class (in packets).
140  *
141  * parent       parent class pointer.
142  *
143  * borrow       class to borrow from (should be either 'parent' or null).
144  *
145  * maxidle      max value allowed for class 'idle' time estimate (this
146  *              parameter determines how large an initial burst of packets
147  *              can be before overlimit action is invoked.
148  *
149  * offtime      how long 'delay' action will delay when class goes over
150  *              limit (this parameter determines the steady-state burst
151  *              size when a class is running over its limit).
152  *
153  * Maxidle and offtime have to be computed from the following:  If the
154  * average packet size is s, the bandwidth fraction allocated to this
155  * class is f, we want to allow b packet bursts, and the gain of the
156  * averaging filter is g (= 1 - 2^(-RM_FILTER_GAIN)), then:
157  *
158  *   ptime = s * nsPerByte * (1 - f) / f
159  *   maxidle = ptime * (1 - g^b) / g^b
160  *   minidle = -ptime * (1 / (f - 1))
161  *   offtime = ptime * (1 + 1/(1 - g) * (1 - g^(b - 1)) / g^(b - 1)
162  *
163  * Operationally, it's convenient to specify maxidle & offtime in units
164  * independent of the link bandwidth so the maxidle & offtime passed to
165  * this routine are the above values multiplied by 8*f/(1000*nsPerByte).
166  * (The constant factor is a scale factor needed to make the parameters
167  * integers.  This scaling also means that the 'unscaled' values of
168  * maxidle*nsecPerByte/8 and offtime*nsecPerByte/8 will be in microseconds,
169  * not nanoseconds.)  Also note that the 'idle' filter computation keeps
170  * an estimate scaled upward by 2^RM_FILTER_GAIN so the passed value of
171  * maxidle also must be scaled upward by this value.  Thus, the passed
172  * values for maxidle and offtime can be computed as follows:
173  *
174  * maxidle = maxidle * 2^RM_FILTER_GAIN * 8 / (1000 * nsecPerByte)
175  * offtime = offtime * 8 / (1000 * nsecPerByte)
176  *
177  * When USE_HRTIME is employed, then maxidle and offtime become:
178  * 	maxidle = maxilde * (8.0 / nsecPerByte);
179  * 	offtime = offtime * (8.0 / nsecPerByte);
180  */
181 struct rm_class *
182 rmc_newclass(int pri, struct rm_ifdat *ifd, u_int nsecPerByte,
183     void (*action)(rm_class_t *, rm_class_t *), int maxq,
184     struct rm_class *parent, struct rm_class *borrow, u_int maxidle,
185     int minidle, u_int offtime, int pktsize, int flags)
186 {
187 	struct rm_class	*cl;
188 	struct rm_class	*peer;
189 	int		 s;
190 
191 	if (pri >= RM_MAXPRIO)
192 		return (NULL);
193 #ifndef ALTQ_RED
194 	if (flags & RMCF_RED) {
195 #ifdef ALTQ_DEBUG
196 		printf("rmc_newclass: RED not configured for CBQ!\n");
197 #endif
198 		return (NULL);
199 	}
200 #endif
201 #ifndef ALTQ_RIO
202 	if (flags & RMCF_RIO) {
203 #ifdef ALTQ_DEBUG
204 		printf("rmc_newclass: RIO not configured for CBQ!\n");
205 #endif
206 		return (NULL);
207 	}
208 #endif
209 #ifndef ALTQ_CODEL
210 	if (flags & RMCF_CODEL) {
211 #ifdef ALTQ_DEBUG
212 		printf("rmc_newclass: CODEL not configured for CBQ!\n");
213 #endif
214 		return (NULL);
215 	}
216 #endif
217 
218 	cl = malloc(sizeof(struct rm_class), M_DEVBUF, M_NOWAIT | M_ZERO);
219 	if (cl == NULL)
220 		return (NULL);
221 	CALLOUT_INIT(&cl->callout_);
222 	cl->q_ = malloc(sizeof(class_queue_t), M_DEVBUF, M_NOWAIT | M_ZERO);
223 	if (cl->q_ == NULL) {
224 		free(cl, M_DEVBUF);
225 		return (NULL);
226 	}
227 
228 	/*
229 	 * Class initialization.
230 	 */
231 	cl->children_ = NULL;
232 	cl->parent_ = parent;
233 	cl->borrow_ = borrow;
234 	cl->leaf_ = 1;
235 	cl->ifdat_ = ifd;
236 	cl->pri_ = pri;
237 	cl->allotment_ = RM_NS_PER_SEC / nsecPerByte; /* Bytes per sec */
238 	cl->depth_ = 0;
239 	cl->qthresh_ = 0;
240 	cl->ns_per_byte_ = nsecPerByte;
241 
242 	qlimit(cl->q_) = maxq;
243 	qtype(cl->q_) = Q_DROPHEAD;
244 	qlen(cl->q_) = 0;
245 	cl->flags_ = flags;
246 
247 #if 1 /* minidle is also scaled in ALTQ */
248 	cl->minidle_ = (minidle * (int)nsecPerByte) / 8;
249 	if (cl->minidle_ > 0)
250 		cl->minidle_ = 0;
251 #else
252 	cl->minidle_ = minidle;
253 #endif
254 	cl->maxidle_ = (maxidle * nsecPerByte) / 8;
255 	if (cl->maxidle_ == 0)
256 		cl->maxidle_ = 1;
257 #if 1 /* offtime is also scaled in ALTQ */
258 	cl->avgidle_ = cl->maxidle_;
259 	cl->offtime_ = ((offtime * nsecPerByte) / 8) >> RM_FILTER_GAIN;
260 	if (cl->offtime_ == 0)
261 		cl->offtime_ = 1;
262 #else
263 	cl->avgidle_ = 0;
264 	cl->offtime_ = (offtime * nsecPerByte) / 8;
265 #endif
266 	cl->overlimit = action;
267 
268 #ifdef ALTQ_RED
269 	if (flags & (RMCF_RED|RMCF_RIO)) {
270 		int red_flags, red_pkttime;
271 
272 		red_flags = 0;
273 		if (flags & RMCF_ECN)
274 			red_flags |= REDF_ECN;
275 		if (flags & RMCF_FLOWVALVE)
276 			red_flags |= REDF_FLOWVALVE;
277 #ifdef ALTQ_RIO
278 		if (flags & RMCF_CLEARDSCP)
279 			red_flags |= RIOF_CLEARDSCP;
280 #endif
281 		red_pkttime = nsecPerByte * pktsize  / 1000;
282 
283 		if (flags & RMCF_RED) {
284 			cl->red_ = red_alloc(0, 0,
285 			    qlimit(cl->q_) * 10/100,
286 			    qlimit(cl->q_) * 30/100,
287 			    red_flags, red_pkttime);
288 			if (cl->red_ != NULL)
289 				qtype(cl->q_) = Q_RED;
290 		}
291 #ifdef ALTQ_RIO
292 		else {
293 			cl->red_ = (red_t *)rio_alloc(0, NULL,
294 						      red_flags, red_pkttime);
295 			if (cl->red_ != NULL)
296 				qtype(cl->q_) = Q_RIO;
297 		}
298 #endif
299 	}
300 #endif /* ALTQ_RED */
301 #ifdef ALTQ_CODEL
302 	if (flags & RMCF_CODEL) {
303 		cl->codel_ = codel_alloc(5, 100, 0);
304 		if (cl->codel_ != NULL)
305 			qtype(cl->q_) = Q_CODEL;
306 	}
307 #endif
308 
309 	/*
310 	 * put the class into the class tree
311 	 */
312 	s = splnet();
313 	IFQ_LOCK(ifd->ifq_);
314 	if ((peer = ifd->active_[pri]) != NULL) {
315 		/* find the last class at this pri */
316 		cl->peer_ = peer;
317 		while (peer->peer_ != ifd->active_[pri])
318 			peer = peer->peer_;
319 		peer->peer_ = cl;
320 	} else {
321 		ifd->active_[pri] = cl;
322 		cl->peer_ = cl;
323 	}
324 
325 	if (cl->parent_) {
326 		cl->next_ = parent->children_;
327 		parent->children_ = cl;
328 		parent->leaf_ = 0;
329 	}
330 
331 	/*
332 	 * Compute the depth of this class and its ancestors in the class
333 	 * hierarchy.
334 	 */
335 	rmc_depth_compute(cl);
336 
337 	/*
338 	 * If CBQ's WRR is enabled, then initialize the class WRR state.
339 	 */
340 	if (ifd->wrr_) {
341 		ifd->num_[pri]++;
342 		ifd->alloc_[pri] += cl->allotment_;
343 		rmc_wrr_set_weights(ifd);
344 	}
345 	IFQ_UNLOCK(ifd->ifq_);
346 	splx(s);
347 	return (cl);
348 }
349 
350 int
351 rmc_modclass(struct rm_class *cl, u_int nsecPerByte, int maxq, u_int maxidle,
352     int minidle, u_int offtime, int pktsize)
353 {
354 	struct rm_ifdat	*ifd;
355 	u_int		 old_allotment;
356 	int		 s;
357 
358 	ifd = cl->ifdat_;
359 	old_allotment = cl->allotment_;
360 
361 	s = splnet();
362 	IFQ_LOCK(ifd->ifq_);
363 	cl->allotment_ = RM_NS_PER_SEC / nsecPerByte; /* Bytes per sec */
364 	cl->qthresh_ = 0;
365 	cl->ns_per_byte_ = nsecPerByte;
366 
367 	qlimit(cl->q_) = maxq;
368 
369 #if 1 /* minidle is also scaled in ALTQ */
370 	cl->minidle_ = (minidle * nsecPerByte) / 8;
371 	if (cl->minidle_ > 0)
372 		cl->minidle_ = 0;
373 #else
374 	cl->minidle_ = minidle;
375 #endif
376 	cl->maxidle_ = (maxidle * nsecPerByte) / 8;
377 	if (cl->maxidle_ == 0)
378 		cl->maxidle_ = 1;
379 #if 1 /* offtime is also scaled in ALTQ */
380 	cl->avgidle_ = cl->maxidle_;
381 	cl->offtime_ = ((offtime * nsecPerByte) / 8) >> RM_FILTER_GAIN;
382 	if (cl->offtime_ == 0)
383 		cl->offtime_ = 1;
384 #else
385 	cl->avgidle_ = 0;
386 	cl->offtime_ = (offtime * nsecPerByte) / 8;
387 #endif
388 
389 	/*
390 	 * If CBQ's WRR is enabled, then initialize the class WRR state.
391 	 */
392 	if (ifd->wrr_) {
393 		ifd->alloc_[cl->pri_] += cl->allotment_ - old_allotment;
394 		rmc_wrr_set_weights(ifd);
395 	}
396 	IFQ_UNLOCK(ifd->ifq_);
397 	splx(s);
398 	return (0);
399 }
400 
401 /*
402  * static void
403  * rmc_wrr_set_weights(struct rm_ifdat *ifdat) - This function computes
404  *	the appropriate run robin weights for the CBQ weighted round robin
405  *	algorithm.
406  *
407  *	Returns: NONE
408  */
409 
410 static void
411 rmc_wrr_set_weights(struct rm_ifdat *ifd)
412 {
413 	int		i;
414 	struct rm_class	*cl, *clh;
415 
416 	for (i = 0; i < RM_MAXPRIO; i++) {
417 		/*
418 		 * This is inverted from that of the simulator to
419 		 * maintain precision.
420 		 */
421 		if (ifd->num_[i] == 0)
422 			ifd->M_[i] = 0;
423 		else
424 			ifd->M_[i] = ifd->alloc_[i] /
425 				(ifd->num_[i] * ifd->maxpkt_);
426 		/*
427 		 * Compute the weighted allotment for each class.
428 		 * This takes the expensive div instruction out
429 		 * of the main loop for the wrr scheduling path.
430 		 * These only get recomputed when a class comes or
431 		 * goes.
432 		 */
433 		if (ifd->active_[i] != NULL) {
434 			clh = cl = ifd->active_[i];
435 			do {
436 				/* safe-guard for slow link or alloc_ == 0 */
437 				if (ifd->M_[i] == 0)
438 					cl->w_allotment_ = 0;
439 				else
440 					cl->w_allotment_ = cl->allotment_ /
441 						ifd->M_[i];
442 				cl = cl->peer_;
443 			} while ((cl != NULL) && (cl != clh));
444 		}
445 	}
446 }
447 
448 int
449 rmc_get_weight(struct rm_ifdat *ifd, int pri)
450 {
451 	if ((pri >= 0) && (pri < RM_MAXPRIO))
452 		return (ifd->M_[pri]);
453 	else
454 		return (0);
455 }
456 
457 /*
458  * static void
459  * rmc_depth_compute(struct rm_class *cl) - This function computes the
460  *	appropriate depth of class 'cl' and its ancestors.
461  *
462  *	Returns:	NONE
463  */
464 
465 static void
466 rmc_depth_compute(struct rm_class *cl)
467 {
468 	rm_class_t	*t = cl, *p;
469 
470 	/*
471 	 * Recompute the depth for the branch of the tree.
472 	 */
473 	while (t != NULL) {
474 		p = t->parent_;
475 		if (p && (t->depth_ >= p->depth_)) {
476 			p->depth_ = t->depth_ + 1;
477 			t = p;
478 		} else
479 			t = NULL;
480 	}
481 }
482 
483 /*
484  * static void
485  * rmc_depth_recompute(struct rm_class *cl) - This function re-computes
486  *	the depth of the tree after a class has been deleted.
487  *
488  *	Returns:	NONE
489  */
490 
491 static void
492 rmc_depth_recompute(rm_class_t *cl)
493 {
494 #if 1 /* ALTQ */
495 	rm_class_t	*p, *t;
496 
497 	p = cl;
498 	while (p != NULL) {
499 		if ((t = p->children_) == NULL) {
500 			p->depth_ = 0;
501 		} else {
502 			int cdepth = 0;
503 
504 			while (t != NULL) {
505 				if (t->depth_ > cdepth)
506 					cdepth = t->depth_;
507 				t = t->next_;
508 			}
509 
510 			if (p->depth_ == cdepth + 1)
511 				/* no change to this parent */
512 				return;
513 
514 			p->depth_ = cdepth + 1;
515 		}
516 
517 		p = p->parent_;
518 	}
519 #else
520 	rm_class_t	*t;
521 
522 	if (cl->depth_ >= 1) {
523 		if (cl->children_ == NULL) {
524 			cl->depth_ = 0;
525 		} else if ((t = cl->children_) != NULL) {
526 			while (t != NULL) {
527 				if (t->children_ != NULL)
528 					rmc_depth_recompute(t);
529 				t = t->next_;
530 			}
531 		} else
532 			rmc_depth_compute(cl);
533 	}
534 #endif
535 }
536 
537 /*
538  * void
539  * rmc_delete_class(struct rm_ifdat *ifdat, struct rm_class *cl) - This
540  *	function deletes a class from the link-sharing structure and frees
541  *	all resources associated with the class.
542  *
543  *	Returns: NONE
544  */
545 
546 void
547 rmc_delete_class(struct rm_ifdat *ifd, struct rm_class *cl)
548 {
549 	struct rm_class	*p, *head, *previous;
550 	int		 s;
551 
552 	ASSERT(cl->children_ == NULL);
553 
554 	if (cl->sleeping_)
555 		CALLOUT_STOP(&cl->callout_);
556 
557 	s = splnet();
558 	IFQ_LOCK(ifd->ifq_);
559 	/*
560 	 * Free packets in the packet queue.
561 	 * XXX - this may not be a desired behavior.  Packets should be
562 	 *		re-queued.
563 	 */
564 	rmc_dropall(cl);
565 
566 	/*
567 	 * If the class has a parent, then remove the class from the
568 	 * class from the parent's children chain.
569 	 */
570 	if (cl->parent_ != NULL) {
571 		head = cl->parent_->children_;
572 		p = previous = head;
573 		if (head->next_ == NULL) {
574 			ASSERT(head == cl);
575 			cl->parent_->children_ = NULL;
576 			cl->parent_->leaf_ = 1;
577 		} else while (p != NULL) {
578 			if (p == cl) {
579 				if (cl == head)
580 					cl->parent_->children_ = cl->next_;
581 				else
582 					previous->next_ = cl->next_;
583 				cl->next_ = NULL;
584 				p = NULL;
585 			} else {
586 				previous = p;
587 				p = p->next_;
588 			}
589 		}
590 	}
591 
592 	/*
593 	 * Delete class from class priority peer list.
594 	 */
595 	if ((p = ifd->active_[cl->pri_]) != NULL) {
596 		/*
597 		 * If there is more than one member of this priority
598 		 * level, then look for class(cl) in the priority level.
599 		 */
600 		if (p != p->peer_) {
601 			while (p->peer_ != cl)
602 				p = p->peer_;
603 			p->peer_ = cl->peer_;
604 
605 			if (ifd->active_[cl->pri_] == cl)
606 				ifd->active_[cl->pri_] = cl->peer_;
607 		} else {
608 			ASSERT(p == cl);
609 			ifd->active_[cl->pri_] = NULL;
610 		}
611 	}
612 
613 	/*
614 	 * Recompute the WRR weights.
615 	 */
616 	if (ifd->wrr_) {
617 		ifd->alloc_[cl->pri_] -= cl->allotment_;
618 		ifd->num_[cl->pri_]--;
619 		rmc_wrr_set_weights(ifd);
620 	}
621 
622 	/*
623 	 * Re-compute the depth of the tree.
624 	 */
625 #if 1 /* ALTQ */
626 	rmc_depth_recompute(cl->parent_);
627 #else
628 	rmc_depth_recompute(ifd->root_);
629 #endif
630 
631 	IFQ_UNLOCK(ifd->ifq_);
632 	splx(s);
633 
634 	/*
635 	 * Free the class structure.
636 	 */
637 	if (cl->red_ != NULL) {
638 #ifdef ALTQ_RIO
639 		if (q_is_rio(cl->q_))
640 			rio_destroy((rio_t *)cl->red_);
641 #endif
642 #ifdef ALTQ_RED
643 		if (q_is_red(cl->q_))
644 			red_destroy(cl->red_);
645 #endif
646 #ifdef ALTQ_CODEL
647 		if (q_is_codel(cl->q_))
648 			codel_destroy(cl->codel_);
649 #endif
650 	}
651 	free(cl->q_, M_DEVBUF);
652 	free(cl, M_DEVBUF);
653 }
654 
655 
656 /*
657  * void
658  * rmc_init(...) - Initialize the resource management data structures
659  *	associated with the output portion of interface 'ifp'.  'ifd' is
660  *	where the structures will be built (for backwards compatibility, the
661  *	structures aren't kept in the ifnet struct).  'nsecPerByte'
662  *	gives the link speed (inverse of bandwidth) in nanoseconds/byte.
663  *	'restart' is the driver-specific routine that the generic 'delay
664  *	until under limit' action will call to restart output.  `maxq'
665  *	is the queue size of the 'link' & 'default' classes.  'maxqueued'
666  *	is the maximum number of packets that the resource management
667  *	code will allow to be queued 'downstream' (this is typically 1).
668  *
669  *	Returns:	NONE
670  */
671 
672 void
673 rmc_init(struct ifaltq *ifq, struct rm_ifdat *ifd, u_int nsecPerByte,
674     void (*restart)(struct ifaltq *), int maxq, int maxqueued, u_int maxidle,
675     int minidle, u_int offtime, int flags)
676 {
677 	int		i, mtu;
678 
679 	/*
680 	 * Initialize the CBQ tracing/debug facility.
681 	 */
682 	CBQTRACEINIT();
683 
684 	bzero((char *)ifd, sizeof (*ifd));
685 	mtu = ifq->altq_ifp->if_mtu;
686 	ifd->ifq_ = ifq;
687 	ifd->restart = restart;
688 	ifd->maxqueued_ = maxqueued;
689 	ifd->ns_per_byte_ = nsecPerByte;
690 	ifd->maxpkt_ = mtu;
691 	ifd->wrr_ = (flags & RMCF_WRR) ? 1 : 0;
692 	ifd->efficient_ = (flags & RMCF_EFFICIENT) ? 1 : 0;
693 #if 1
694 	ifd->maxiftime_ = mtu * nsecPerByte / 1000 * 16;
695 	if (mtu * nsecPerByte > 10 * 1000000)
696 		ifd->maxiftime_ /= 4;
697 #endif
698 
699 	reset_cutoff(ifd);
700 	CBQTRACE(rmc_init, 'INIT', ifd->cutoff_);
701 
702 	/*
703 	 * Initialize the CBQ's WRR state.
704 	 */
705 	for (i = 0; i < RM_MAXPRIO; i++) {
706 		ifd->alloc_[i] = 0;
707 		ifd->M_[i] = 0;
708 		ifd->num_[i] = 0;
709 		ifd->na_[i] = 0;
710 		ifd->active_[i] = NULL;
711 	}
712 
713 	/*
714 	 * Initialize current packet state.
715 	 */
716 	ifd->qi_ = 0;
717 	ifd->qo_ = 0;
718 	for (i = 0; i < RM_MAXQUEUED; i++) {
719 		ifd->class_[i] = NULL;
720 		ifd->curlen_[i] = 0;
721 		ifd->borrowed_[i] = NULL;
722 	}
723 
724 	/*
725 	 * Create the root class of the link-sharing structure.
726 	 */
727 	if ((ifd->root_ = rmc_newclass(0, ifd,
728 				       nsecPerByte,
729 				       rmc_root_overlimit, maxq, 0, 0,
730 				       maxidle, minidle, offtime,
731 				       0, 0)) == NULL) {
732 		printf("rmc_init: root class not allocated\n");
733 		return ;
734 	}
735 	ifd->root_->depth_ = 0;
736 }
737 
738 /*
739  * void
740  * rmc_queue_packet(struct rm_class *cl, mbuf_t *m) - Add packet given by
741  *	mbuf 'm' to queue for resource class 'cl'.  This routine is called
742  *	by a driver's if_output routine.  This routine must be called with
743  *	output packet completion interrupts locked out (to avoid racing with
744  *	rmc_dequeue_next).
745  *
746  *	Returns:	0 on successful queueing
747  *			-1 when packet drop occurs
748  */
749 int
750 rmc_queue_packet(struct rm_class *cl, mbuf_t *m)
751 {
752 	struct timeval	 now;
753 	struct rm_ifdat *ifd = cl->ifdat_;
754 	int		 cpri = cl->pri_;
755 	int		 is_empty = qempty(cl->q_);
756 
757 	RM_GETTIME(now);
758 	if (ifd->cutoff_ > 0) {
759 		if (TV_LT(&cl->undertime_, &now)) {
760 			if (ifd->cutoff_ > cl->depth_)
761 				ifd->cutoff_ = cl->depth_;
762 			CBQTRACE(rmc_queue_packet, 'ffoc', cl->depth_);
763 		}
764 #if 1 /* ALTQ */
765 		else {
766 			/*
767 			 * the class is overlimit. if the class has
768 			 * underlimit ancestors, set cutoff to the lowest
769 			 * depth among them.
770 			 */
771 			struct rm_class *borrow = cl->borrow_;
772 
773 			while (borrow != NULL &&
774 			       borrow->depth_ < ifd->cutoff_) {
775 				if (TV_LT(&borrow->undertime_, &now)) {
776 					ifd->cutoff_ = borrow->depth_;
777 					CBQTRACE(rmc_queue_packet, 'ffob', ifd->cutoff_);
778 					break;
779 				}
780 				borrow = borrow->borrow_;
781 			}
782 		}
783 #else /* !ALTQ */
784 		else if ((ifd->cutoff_ > 1) && cl->borrow_) {
785 			if (TV_LT(&cl->borrow_->undertime_, &now)) {
786 				ifd->cutoff_ = cl->borrow_->depth_;
787 				CBQTRACE(rmc_queue_packet, 'ffob',
788 					 cl->borrow_->depth_);
789 			}
790 		}
791 #endif /* !ALTQ */
792 	}
793 
794 	if (_rmc_addq(cl, m) < 0)
795 		/* failed */
796 		return (-1);
797 
798 	if (is_empty) {
799 		CBQTRACE(rmc_queue_packet, 'ytpe', cl->stats_.handle);
800 		ifd->na_[cpri]++;
801 	}
802 
803 	if (qlen(cl->q_) > qlimit(cl->q_)) {
804 		/* note: qlimit can be set to 0 or 1 */
805 		rmc_drop_action(cl);
806 		return (-1);
807 	}
808 	return (0);
809 }
810 
811 /*
812  * void
813  * rmc_tl_satisfied(struct rm_ifdat *ifd, struct timeval *now) - Check all
814  *	classes to see if there are satified.
815  */
816 
817 static void
818 rmc_tl_satisfied(struct rm_ifdat *ifd, struct timeval *now)
819 {
820 	int		 i;
821 	rm_class_t	*p, *bp;
822 
823 	for (i = RM_MAXPRIO - 1; i >= 0; i--) {
824 		if ((bp = ifd->active_[i]) != NULL) {
825 			p = bp;
826 			do {
827 				if (!rmc_satisfied(p, now)) {
828 					ifd->cutoff_ = p->depth_;
829 					return;
830 				}
831 				p = p->peer_;
832 			} while (p != bp);
833 		}
834 	}
835 
836 	reset_cutoff(ifd);
837 }
838 
839 /*
840  * rmc_satisfied - Return 1 of the class is satisfied.  O, otherwise.
841  */
842 
843 static int
844 rmc_satisfied(struct rm_class *cl, struct timeval *now)
845 {
846 	rm_class_t	*p;
847 
848 	if (cl == NULL)
849 		return (1);
850 	if (TV_LT(now, &cl->undertime_))
851 		return (1);
852 	if (cl->depth_ == 0) {
853 		if (!cl->sleeping_ && (qlen(cl->q_) > cl->qthresh_))
854 			return (0);
855 		else
856 			return (1);
857 	}
858 	if (cl->children_ != NULL) {
859 		p = cl->children_;
860 		while (p != NULL) {
861 			if (!rmc_satisfied(p, now))
862 				return (0);
863 			p = p->next_;
864 		}
865 	}
866 
867 	return (1);
868 }
869 
870 /*
871  * Return 1 if class 'cl' is under limit or can borrow from a parent,
872  * 0 if overlimit.  As a side-effect, this routine will invoke the
873  * class overlimit action if the class if overlimit.
874  */
875 
876 static int
877 rmc_under_limit(struct rm_class *cl, struct timeval *now)
878 {
879 	rm_class_t	*p = cl;
880 	rm_class_t	*top;
881 	struct rm_ifdat	*ifd = cl->ifdat_;
882 
883 	ifd->borrowed_[ifd->qi_] = NULL;
884 	/*
885 	 * If cl is the root class, then always return that it is
886 	 * underlimit.  Otherwise, check to see if the class is underlimit.
887 	 */
888 	if (cl->parent_ == NULL)
889 		return (1);
890 
891 	if (cl->sleeping_) {
892 		if (TV_LT(now, &cl->undertime_))
893 			return (0);
894 
895 		CALLOUT_STOP(&cl->callout_);
896 		cl->sleeping_ = 0;
897 		cl->undertime_.tv_sec = 0;
898 		return (1);
899 	}
900 
901 	top = NULL;
902 	while (cl->undertime_.tv_sec && TV_LT(now, &cl->undertime_)) {
903 		if (((cl = cl->borrow_) == NULL) ||
904 		    (cl->depth_ > ifd->cutoff_)) {
905 #ifdef ADJUST_CUTOFF
906 			if (cl != NULL)
907 				/* cutoff is taking effect, just
908 				   return false without calling
909 				   the delay action. */
910 				return (0);
911 #endif
912 #ifdef BORROW_OFFTIME
913 			/*
914 			 * check if the class can borrow offtime too.
915 			 * borrow offtime from the top of the borrow
916 			 * chain if the top class is not overloaded.
917 			 */
918 			if (cl != NULL) {
919 				/* cutoff is taking effect, use this class as top. */
920 				top = cl;
921 				CBQTRACE(rmc_under_limit, 'ffou', ifd->cutoff_);
922 			}
923 			if (top != NULL && top->avgidle_ == top->minidle_)
924 				top = NULL;
925 			p->overtime_ = *now;
926 			(p->overlimit)(p, top);
927 #else
928 			p->overtime_ = *now;
929 			(p->overlimit)(p, NULL);
930 #endif
931 			return (0);
932 		}
933 		top = cl;
934 	}
935 
936 	if (cl != p)
937 		ifd->borrowed_[ifd->qi_] = cl;
938 	return (1);
939 }
940 
941 /*
942  * _rmc_wrr_dequeue_next() - This is scheduler for WRR as opposed to
943  *	Packet-by-packet round robin.
944  *
945  * The heart of the weighted round-robin scheduler, which decides which
946  * class next gets to send a packet.  Highest priority first, then
947  * weighted round-robin within priorites.
948  *
949  * Each able-to-send class gets to send until its byte allocation is
950  * exhausted.  Thus, the active pointer is only changed after a class has
951  * exhausted its allocation.
952  *
953  * If the scheduler finds no class that is underlimit or able to borrow,
954  * then the first class found that had a nonzero queue and is allowed to
955  * borrow gets to send.
956  */
957 
958 static mbuf_t *
959 _rmc_wrr_dequeue_next(struct rm_ifdat *ifd, int op)
960 {
961 	struct rm_class	*cl = NULL, *first = NULL;
962 	u_int		 deficit;
963 	int		 cpri;
964 	mbuf_t		*m;
965 	struct timeval	 now;
966 
967 	RM_GETTIME(now);
968 
969 	/*
970 	 * if the driver polls the top of the queue and then removes
971 	 * the polled packet, we must return the same packet.
972 	 */
973 	if (op == ALTDQ_REMOVE && ifd->pollcache_) {
974 		cl = ifd->pollcache_;
975 		cpri = cl->pri_;
976 		if (ifd->efficient_) {
977 			/* check if this class is overlimit */
978 			if (cl->undertime_.tv_sec != 0 &&
979 			    rmc_under_limit(cl, &now) == 0)
980 				first = cl;
981 		}
982 		ifd->pollcache_ = NULL;
983 		goto _wrr_out;
984 	}
985 	else {
986 		/* mode == ALTDQ_POLL || pollcache == NULL */
987 		ifd->pollcache_ = NULL;
988 		ifd->borrowed_[ifd->qi_] = NULL;
989 	}
990 #ifdef ADJUST_CUTOFF
991  _again:
992 #endif
993 	for (cpri = RM_MAXPRIO - 1; cpri >= 0; cpri--) {
994 		if (ifd->na_[cpri] == 0)
995 			continue;
996 		deficit = 0;
997 		/*
998 		 * Loop through twice for a priority level, if some class
999 		 * was unable to send a packet the first round because
1000 		 * of the weighted round-robin mechanism.
1001 		 * During the second loop at this level, deficit==2.
1002 		 * (This second loop is not needed if for every class,
1003 		 * "M[cl->pri_])" times "cl->allotment" is greater than
1004 		 * the byte size for the largest packet in the class.)
1005 		 */
1006  _wrr_loop:
1007 		cl = ifd->active_[cpri];
1008 		ASSERT(cl != NULL);
1009 		do {
1010 			if ((deficit < 2) && (cl->bytes_alloc_ <= 0))
1011 				cl->bytes_alloc_ += cl->w_allotment_;
1012 			if (!qempty(cl->q_)) {
1013 				if ((cl->undertime_.tv_sec == 0) ||
1014 				    rmc_under_limit(cl, &now)) {
1015 					if (cl->bytes_alloc_ > 0 || deficit > 1)
1016 						goto _wrr_out;
1017 
1018 					/* underlimit but no alloc */
1019 					deficit = 1;
1020 #if 1
1021 					ifd->borrowed_[ifd->qi_] = NULL;
1022 #endif
1023 				}
1024 				else if (first == NULL && cl->borrow_ != NULL)
1025 					first = cl; /* borrowing candidate */
1026 			}
1027 
1028 			cl->bytes_alloc_ = 0;
1029 			cl = cl->peer_;
1030 		} while (cl != ifd->active_[cpri]);
1031 
1032 		if (deficit == 1) {
1033 			/* first loop found an underlimit class with deficit */
1034 			/* Loop on same priority level, with new deficit.  */
1035 			deficit = 2;
1036 			goto _wrr_loop;
1037 		}
1038 	}
1039 
1040 #ifdef ADJUST_CUTOFF
1041 	/*
1042 	 * no underlimit class found.  if cutoff is taking effect,
1043 	 * increase cutoff and try again.
1044 	 */
1045 	if (first != NULL && ifd->cutoff_ < ifd->root_->depth_) {
1046 		ifd->cutoff_++;
1047 		CBQTRACE(_rmc_wrr_dequeue_next, 'ojda', ifd->cutoff_);
1048 		goto _again;
1049 	}
1050 #endif /* ADJUST_CUTOFF */
1051 	/*
1052 	 * If LINK_EFFICIENCY is turned on, then the first overlimit
1053 	 * class we encounter will send a packet if all the classes
1054 	 * of the link-sharing structure are overlimit.
1055 	 */
1056 	reset_cutoff(ifd);
1057 	CBQTRACE(_rmc_wrr_dequeue_next, 'otsr', ifd->cutoff_);
1058 
1059 	if (!ifd->efficient_ || first == NULL)
1060 		return (NULL);
1061 
1062 	cl = first;
1063 	cpri = cl->pri_;
1064 #if 0	/* too time-consuming for nothing */
1065 	if (cl->sleeping_)
1066 		CALLOUT_STOP(&cl->callout_);
1067 	cl->sleeping_ = 0;
1068 	cl->undertime_.tv_sec = 0;
1069 #endif
1070 	ifd->borrowed_[ifd->qi_] = cl->borrow_;
1071 	ifd->cutoff_ = cl->borrow_->depth_;
1072 
1073 	/*
1074 	 * Deque the packet and do the book keeping...
1075 	 */
1076  _wrr_out:
1077 	if (op == ALTDQ_REMOVE) {
1078 		m = _rmc_getq(cl);
1079 		if (m == NULL)
1080 			panic("_rmc_wrr_dequeue_next");
1081 		if (qempty(cl->q_))
1082 			ifd->na_[cpri]--;
1083 
1084 		/*
1085 		 * Update class statistics and link data.
1086 		 */
1087 		if (cl->bytes_alloc_ > 0)
1088 			cl->bytes_alloc_ -= m_pktlen(m);
1089 
1090 		if ((cl->bytes_alloc_ <= 0) || first == cl)
1091 			ifd->active_[cl->pri_] = cl->peer_;
1092 		else
1093 			ifd->active_[cl->pri_] = cl;
1094 
1095 		ifd->class_[ifd->qi_] = cl;
1096 		ifd->curlen_[ifd->qi_] = m_pktlen(m);
1097 		ifd->now_[ifd->qi_] = now;
1098 		ifd->qi_ = (ifd->qi_ + 1) % ifd->maxqueued_;
1099 		ifd->queued_++;
1100 	} else {
1101 		/* mode == ALTDQ_PPOLL */
1102 		m = _rmc_pollq(cl);
1103 		ifd->pollcache_ = cl;
1104 	}
1105 	return (m);
1106 }
1107 
1108 /*
1109  * Dequeue & return next packet from the highest priority class that
1110  * has a packet to send & has enough allocation to send it.  This
1111  * routine is called by a driver whenever it needs a new packet to
1112  * output.
1113  */
1114 static mbuf_t *
1115 _rmc_prr_dequeue_next(struct rm_ifdat *ifd, int op)
1116 {
1117 	mbuf_t		*m;
1118 	int		 cpri;
1119 	struct rm_class	*cl, *first = NULL;
1120 	struct timeval	 now;
1121 
1122 	RM_GETTIME(now);
1123 
1124 	/*
1125 	 * if the driver polls the top of the queue and then removes
1126 	 * the polled packet, we must return the same packet.
1127 	 */
1128 	if (op == ALTDQ_REMOVE && ifd->pollcache_) {
1129 		cl = ifd->pollcache_;
1130 		cpri = cl->pri_;
1131 		ifd->pollcache_ = NULL;
1132 		goto _prr_out;
1133 	} else {
1134 		/* mode == ALTDQ_POLL || pollcache == NULL */
1135 		ifd->pollcache_ = NULL;
1136 		ifd->borrowed_[ifd->qi_] = NULL;
1137 	}
1138 #ifdef ADJUST_CUTOFF
1139  _again:
1140 #endif
1141 	for (cpri = RM_MAXPRIO - 1; cpri >= 0; cpri--) {
1142 		if (ifd->na_[cpri] == 0)
1143 			continue;
1144 		cl = ifd->active_[cpri];
1145 		ASSERT(cl != NULL);
1146 		do {
1147 			if (!qempty(cl->q_)) {
1148 				if ((cl->undertime_.tv_sec == 0) ||
1149 				    rmc_under_limit(cl, &now))
1150 					goto _prr_out;
1151 				if (first == NULL && cl->borrow_ != NULL)
1152 					first = cl;
1153 			}
1154 			cl = cl->peer_;
1155 		} while (cl != ifd->active_[cpri]);
1156 	}
1157 
1158 #ifdef ADJUST_CUTOFF
1159 	/*
1160 	 * no underlimit class found.  if cutoff is taking effect, increase
1161 	 * cutoff and try again.
1162 	 */
1163 	if (first != NULL && ifd->cutoff_ < ifd->root_->depth_) {
1164 		ifd->cutoff_++;
1165 		goto _again;
1166 	}
1167 #endif /* ADJUST_CUTOFF */
1168 	/*
1169 	 * If LINK_EFFICIENCY is turned on, then the first overlimit
1170 	 * class we encounter will send a packet if all the classes
1171 	 * of the link-sharing structure are overlimit.
1172 	 */
1173 	reset_cutoff(ifd);
1174 	if (!ifd->efficient_ || first == NULL)
1175 		return (NULL);
1176 
1177 	cl = first;
1178 	cpri = cl->pri_;
1179 #if 0	/* too time-consuming for nothing */
1180 	if (cl->sleeping_)
1181 		CALLOUT_STOP(&cl->callout_);
1182 	cl->sleeping_ = 0;
1183 	cl->undertime_.tv_sec = 0;
1184 #endif
1185 	ifd->borrowed_[ifd->qi_] = cl->borrow_;
1186 	ifd->cutoff_ = cl->borrow_->depth_;
1187 
1188 	/*
1189 	 * Deque the packet and do the book keeping...
1190 	 */
1191  _prr_out:
1192 	if (op == ALTDQ_REMOVE) {
1193 		m = _rmc_getq(cl);
1194 		if (m == NULL)
1195 			panic("_rmc_prr_dequeue_next");
1196 		if (qempty(cl->q_))
1197 			ifd->na_[cpri]--;
1198 
1199 		ifd->active_[cpri] = cl->peer_;
1200 
1201 		ifd->class_[ifd->qi_] = cl;
1202 		ifd->curlen_[ifd->qi_] = m_pktlen(m);
1203 		ifd->now_[ifd->qi_] = now;
1204 		ifd->qi_ = (ifd->qi_ + 1) % ifd->maxqueued_;
1205 		ifd->queued_++;
1206 	} else {
1207 		/* mode == ALTDQ_POLL */
1208 		m = _rmc_pollq(cl);
1209 		ifd->pollcache_ = cl;
1210 	}
1211 	return (m);
1212 }
1213 
1214 /*
1215  * mbuf_t *
1216  * rmc_dequeue_next(struct rm_ifdat *ifd, struct timeval *now) - this function
1217  *	is invoked by the packet driver to get the next packet to be
1218  *	dequeued and output on the link.  If WRR is enabled, then the
1219  *	WRR dequeue next routine will determine the next packet to sent.
1220  *	Otherwise, packet-by-packet round robin is invoked.
1221  *
1222  *	Returns:	NULL, if a packet is not available or if all
1223  *			classes are overlimit.
1224  *
1225  *			Otherwise, Pointer to the next packet.
1226  */
1227 
1228 mbuf_t *
1229 rmc_dequeue_next(struct rm_ifdat *ifd, int mode)
1230 {
1231 	if (ifd->queued_ >= ifd->maxqueued_)
1232 		return (NULL);
1233 	else if (ifd->wrr_)
1234 		return (_rmc_wrr_dequeue_next(ifd, mode));
1235 	else
1236 		return (_rmc_prr_dequeue_next(ifd, mode));
1237 }
1238 
1239 /*
1240  * Update the utilization estimate for the packet that just completed.
1241  * The packet's class & the parent(s) of that class all get their
1242  * estimators updated.  This routine is called by the driver's output-
1243  * packet-completion interrupt service routine.
1244  */
1245 
1246 /*
1247  * a macro to approximate "divide by 1000" that gives 0.000999,
1248  * if a value has enough effective digits.
1249  * (on pentium, mul takes 9 cycles but div takes 46!)
1250  */
1251 #define	NSEC_TO_USEC(t)	(((t) >> 10) + ((t) >> 16) + ((t) >> 17))
1252 void
1253 rmc_update_class_util(struct rm_ifdat *ifd)
1254 {
1255 	int		 idle, avgidle, pktlen;
1256 	int		 pkt_time, tidle;
1257 	rm_class_t	*cl, *borrowed;
1258 	rm_class_t	*borrows;
1259 	struct timeval	*nowp;
1260 
1261 	/*
1262 	 * Get the most recent completed class.
1263 	 */
1264 	if ((cl = ifd->class_[ifd->qo_]) == NULL)
1265 		return;
1266 
1267 	pktlen = ifd->curlen_[ifd->qo_];
1268 	borrowed = ifd->borrowed_[ifd->qo_];
1269 	borrows = borrowed;
1270 
1271 	PKTCNTR_ADD(&cl->stats_.xmit_cnt, pktlen);
1272 
1273 	/*
1274 	 * Run estimator on class and its ancestors.
1275 	 */
1276 	/*
1277 	 * rm_update_class_util is designed to be called when the
1278 	 * transfer is completed from a xmit complete interrupt,
1279 	 * but most drivers don't implement an upcall for that.
1280 	 * so, just use estimated completion time.
1281 	 * as a result, ifd->qi_ and ifd->qo_ are always synced.
1282 	 */
1283 	nowp = &ifd->now_[ifd->qo_];
1284 	/* get pkt_time (for link) in usec */
1285 #if 1  /* use approximation */
1286 	pkt_time = ifd->curlen_[ifd->qo_] * ifd->ns_per_byte_;
1287 	pkt_time = NSEC_TO_USEC(pkt_time);
1288 #else
1289 	pkt_time = ifd->curlen_[ifd->qo_] * ifd->ns_per_byte_ / 1000;
1290 #endif
1291 #if 1 /* ALTQ4PPP */
1292 	if (TV_LT(nowp, &ifd->ifnow_)) {
1293 		int iftime;
1294 
1295 		/*
1296 		 * make sure the estimated completion time does not go
1297 		 * too far.  it can happen when the link layer supports
1298 		 * data compression or the interface speed is set to
1299 		 * a much lower value.
1300 		 */
1301 		TV_DELTA(&ifd->ifnow_, nowp, iftime);
1302 		if (iftime+pkt_time < ifd->maxiftime_) {
1303 			TV_ADD_DELTA(&ifd->ifnow_, pkt_time, &ifd->ifnow_);
1304 		} else {
1305 			TV_ADD_DELTA(nowp, ifd->maxiftime_, &ifd->ifnow_);
1306 		}
1307 	} else {
1308 		TV_ADD_DELTA(nowp, pkt_time, &ifd->ifnow_);
1309 	}
1310 #else
1311 	if (TV_LT(nowp, &ifd->ifnow_)) {
1312 		TV_ADD_DELTA(&ifd->ifnow_, pkt_time, &ifd->ifnow_);
1313 	} else {
1314 		TV_ADD_DELTA(nowp, pkt_time, &ifd->ifnow_);
1315 	}
1316 #endif
1317 
1318 	while (cl != NULL) {
1319 		TV_DELTA(&ifd->ifnow_, &cl->last_, idle);
1320 		if (idle >= 2000000)
1321 			/*
1322 			 * this class is idle enough, reset avgidle.
1323 			 * (TV_DELTA returns 2000000 us when delta is large.)
1324 			 */
1325 			cl->avgidle_ = cl->maxidle_;
1326 
1327 		/* get pkt_time (for class) in usec */
1328 #if 1  /* use approximation */
1329 		pkt_time = pktlen * cl->ns_per_byte_;
1330 		pkt_time = NSEC_TO_USEC(pkt_time);
1331 #else
1332 		pkt_time = pktlen * cl->ns_per_byte_ / 1000;
1333 #endif
1334 		idle -= pkt_time;
1335 
1336 		avgidle = cl->avgidle_;
1337 		avgidle += idle - (avgidle >> RM_FILTER_GAIN);
1338 		cl->avgidle_ = avgidle;
1339 
1340 		/* Are we overlimit ? */
1341 		if (avgidle <= 0) {
1342 			CBQTRACE(rmc_update_class_util, 'milo', cl->stats_.handle);
1343 #if 1 /* ALTQ */
1344 			/*
1345 			 * need some lower bound for avgidle, otherwise
1346 			 * a borrowing class gets unbounded penalty.
1347 			 */
1348 			if (avgidle < cl->minidle_)
1349 				avgidle = cl->avgidle_ = cl->minidle_;
1350 #endif
1351 			/* set next idle to make avgidle 0 */
1352 			tidle = pkt_time +
1353 				(((1 - RM_POWER) * avgidle) >> RM_FILTER_GAIN);
1354 			TV_ADD_DELTA(nowp, tidle, &cl->undertime_);
1355 			++cl->stats_.over;
1356 		} else {
1357 			cl->avgidle_ =
1358 			    (avgidle > cl->maxidle_) ? cl->maxidle_ : avgidle;
1359 			cl->undertime_.tv_sec = 0;
1360 			if (cl->sleeping_) {
1361 				CALLOUT_STOP(&cl->callout_);
1362 				cl->sleeping_ = 0;
1363 			}
1364 		}
1365 
1366 		if (borrows != NULL) {
1367 			if (borrows != cl)
1368 				++cl->stats_.borrows;
1369 			else
1370 				borrows = NULL;
1371 		}
1372 		cl->last_ = ifd->ifnow_;
1373 		cl->last_pkttime_ = pkt_time;
1374 
1375 #if 1
1376 		if (cl->parent_ == NULL) {
1377 			/* take stats of root class */
1378 			PKTCNTR_ADD(&cl->stats_.xmit_cnt, pktlen);
1379 		}
1380 #endif
1381 
1382 		cl = cl->parent_;
1383 	}
1384 
1385 	/*
1386 	 * Check to see if cutoff needs to set to a new level.
1387 	 */
1388 	cl = ifd->class_[ifd->qo_];
1389 	if (borrowed && (ifd->cutoff_ >= borrowed->depth_)) {
1390 #if 1 /* ALTQ */
1391 		if ((qlen(cl->q_) <= 0) || TV_LT(nowp, &borrowed->undertime_)) {
1392 			rmc_tl_satisfied(ifd, nowp);
1393 			CBQTRACE(rmc_update_class_util, 'broe', ifd->cutoff_);
1394 		} else {
1395 			ifd->cutoff_ = borrowed->depth_;
1396 			CBQTRACE(rmc_update_class_util, 'ffob', borrowed->depth_);
1397 		}
1398 #else /* !ALTQ */
1399 		if ((qlen(cl->q_) <= 1) || TV_LT(&now, &borrowed->undertime_)) {
1400 			reset_cutoff(ifd);
1401 #ifdef notdef
1402 			rmc_tl_satisfied(ifd, &now);
1403 #endif
1404 			CBQTRACE(rmc_update_class_util, 'broe', ifd->cutoff_);
1405 		} else {
1406 			ifd->cutoff_ = borrowed->depth_;
1407 			CBQTRACE(rmc_update_class_util, 'ffob', borrowed->depth_);
1408 		}
1409 #endif /* !ALTQ */
1410 	}
1411 
1412 	/*
1413 	 * Release class slot
1414 	 */
1415 	ifd->borrowed_[ifd->qo_] = NULL;
1416 	ifd->class_[ifd->qo_] = NULL;
1417 	ifd->qo_ = (ifd->qo_ + 1) % ifd->maxqueued_;
1418 	ifd->queued_--;
1419 }
1420 
1421 /*
1422  * void
1423  * rmc_drop_action(struct rm_class *cl) - Generic (not protocol-specific)
1424  *	over-limit action routines.  These get invoked by rmc_under_limit()
1425  *	if a class with packets to send if over its bandwidth limit & can't
1426  *	borrow from a parent class.
1427  *
1428  *	Returns: NONE
1429  */
1430 
1431 static void
1432 rmc_drop_action(struct rm_class *cl)
1433 {
1434 	struct rm_ifdat	*ifd = cl->ifdat_;
1435 
1436 	ASSERT(qlen(cl->q_) > 0);
1437 	_rmc_dropq(cl);
1438 	if (qempty(cl->q_))
1439 		ifd->na_[cl->pri_]--;
1440 }
1441 
1442 void rmc_dropall(struct rm_class *cl)
1443 {
1444 	struct rm_ifdat	*ifd = cl->ifdat_;
1445 
1446 	if (!qempty(cl->q_)) {
1447 		_flushq(cl->q_);
1448 
1449 		ifd->na_[cl->pri_]--;
1450 	}
1451 }
1452 
1453 #if (__FreeBSD_version > 300000)
1454 /* hzto() is removed from FreeBSD-3.0 */
1455 static int hzto(struct timeval *);
1456 
1457 static int
1458 hzto(tv)
1459 	struct timeval *tv;
1460 {
1461 	struct timeval t2;
1462 
1463 	getmicrotime(&t2);
1464 	t2.tv_sec = tv->tv_sec - t2.tv_sec;
1465 	t2.tv_usec = tv->tv_usec - t2.tv_usec;
1466 	return (tvtohz(&t2));
1467 }
1468 #endif /* __FreeBSD_version > 300000 */
1469 
1470 /*
1471  * void
1472  * rmc_delay_action(struct rm_class *cl) - This function is the generic CBQ
1473  *	delay action routine.  It is invoked via rmc_under_limit when the
1474  *	packet is discoverd to be overlimit.
1475  *
1476  *	If the delay action is result of borrow class being overlimit, then
1477  *	delay for the offtime of the borrowing class that is overlimit.
1478  *
1479  *	Returns: NONE
1480  */
1481 
1482 void
1483 rmc_delay_action(struct rm_class *cl, struct rm_class *borrow)
1484 {
1485 	int	delay, t, extradelay;
1486 
1487 	cl->stats_.overactions++;
1488 	TV_DELTA(&cl->undertime_, &cl->overtime_, delay);
1489 #ifndef BORROW_OFFTIME
1490 	delay += cl->offtime_;
1491 #endif
1492 
1493 	if (!cl->sleeping_) {
1494 		CBQTRACE(rmc_delay_action, 'yled', cl->stats_.handle);
1495 #ifdef BORROW_OFFTIME
1496 		if (borrow != NULL)
1497 			extradelay = borrow->offtime_;
1498 		else
1499 #endif
1500 			extradelay = cl->offtime_;
1501 
1502 #ifdef ALTQ
1503 		/*
1504 		 * XXX recalculate suspend time:
1505 		 * current undertime is (tidle + pkt_time) calculated
1506 		 * from the last transmission.
1507 		 *	tidle: time required to bring avgidle back to 0
1508 		 *	pkt_time: target waiting time for this class
1509 		 * we need to replace pkt_time by offtime
1510 		 */
1511 		extradelay -= cl->last_pkttime_;
1512 #endif
1513 		if (extradelay > 0) {
1514 			TV_ADD_DELTA(&cl->undertime_, extradelay, &cl->undertime_);
1515 			delay += extradelay;
1516 		}
1517 
1518 		cl->sleeping_ = 1;
1519 		cl->stats_.delays++;
1520 
1521 		/*
1522 		 * Since packets are phased randomly with respect to the
1523 		 * clock, 1 tick (the next clock tick) can be an arbitrarily
1524 		 * short time so we have to wait for at least two ticks.
1525 		 * NOTE:  If there's no other traffic, we need the timer as
1526 		 * a 'backstop' to restart this class.
1527 		 */
1528 		if (delay > tick * 2) {
1529 			/* FreeBSD rounds up the tick */
1530 			t = hzto(&cl->undertime_);
1531 		} else
1532 			t = 2;
1533 		CALLOUT_RESET(&cl->callout_, t,
1534 			      (timeout_t *)rmc_restart, (caddr_t)cl);
1535 	}
1536 }
1537 
1538 /*
1539  * void
1540  * rmc_restart() - is just a helper routine for rmc_delay_action -- it is
1541  *	called by the system timer code & is responsible checking if the
1542  *	class is still sleeping (it might have been restarted as a side
1543  *	effect of the queue scan on a packet arrival) and, if so, restarting
1544  *	output for the class.  Inspecting the class state & restarting output
1545  *	require locking the class structure.  In general the driver is
1546  *	responsible for locking but this is the only routine that is not
1547  *	called directly or indirectly from the interface driver so it has
1548  *	know about system locking conventions.  Under bsd, locking is done
1549  *	by raising IPL to splimp so that's what's implemented here.  On a
1550  *	different system this would probably need to be changed.
1551  *
1552  *	Returns:	NONE
1553  */
1554 
1555 static void
1556 rmc_restart(struct rm_class *cl)
1557 {
1558 	struct rm_ifdat	*ifd = cl->ifdat_;
1559 	int		 s;
1560 
1561 	s = splnet();
1562 	IFQ_LOCK(ifd->ifq_);
1563 	if (cl->sleeping_) {
1564 		cl->sleeping_ = 0;
1565 		cl->undertime_.tv_sec = 0;
1566 
1567 		if (ifd->queued_ < ifd->maxqueued_ && ifd->restart != NULL) {
1568 			CBQTRACE(rmc_restart, 'trts', cl->stats_.handle);
1569 			(ifd->restart)(ifd->ifq_);
1570 		}
1571 	}
1572 	IFQ_UNLOCK(ifd->ifq_);
1573 	splx(s);
1574 }
1575 
1576 /*
1577  * void
1578  * rmc_root_overlimit(struct rm_class *cl) - This the generic overlimit
1579  *	handling routine for the root class of the link sharing structure.
1580  *
1581  *	Returns: NONE
1582  */
1583 
1584 static void
1585 rmc_root_overlimit(struct rm_class *cl, struct rm_class *borrow)
1586 {
1587     panic("rmc_root_overlimit");
1588 }
1589 
1590 /*
1591  * Packet Queue handling routines.  Eventually, this is to localize the
1592  *	effects on the code whether queues are red queues or droptail
1593  *	queues.
1594  */
1595 
1596 static int
1597 _rmc_addq(rm_class_t *cl, mbuf_t *m)
1598 {
1599 #ifdef ALTQ_RIO
1600 	if (q_is_rio(cl->q_))
1601 		return rio_addq((rio_t *)cl->red_, cl->q_, m, cl->pktattr_);
1602 #endif
1603 #ifdef ALTQ_RED
1604 	if (q_is_red(cl->q_))
1605 		return red_addq(cl->red_, cl->q_, m, cl->pktattr_);
1606 #endif /* ALTQ_RED */
1607 #ifdef ALTQ_CODEL
1608 	if (q_is_codel(cl->q_))
1609 		return codel_addq(cl->codel_, cl->q_, m);
1610 #endif
1611 
1612 	if (cl->flags_ & RMCF_CLEARDSCP)
1613 		write_dsfield(m, cl->pktattr_, 0);
1614 
1615 	_addq(cl->q_, m);
1616 	return (0);
1617 }
1618 
1619 /* note: _rmc_dropq is not called for red */
1620 static void
1621 _rmc_dropq(rm_class_t *cl)
1622 {
1623 	mbuf_t	*m;
1624 
1625 	if ((m = _getq(cl->q_)) != NULL)
1626 		m_freem(m);
1627 }
1628 
1629 static mbuf_t *
1630 _rmc_getq(rm_class_t *cl)
1631 {
1632 #ifdef ALTQ_RIO
1633 	if (q_is_rio(cl->q_))
1634 		return rio_getq((rio_t *)cl->red_, cl->q_);
1635 #endif
1636 #ifdef ALTQ_RED
1637 	if (q_is_red(cl->q_))
1638 		return red_getq(cl->red_, cl->q_);
1639 #endif
1640 #ifdef ALTQ_CODEL
1641 	if (q_is_codel(cl->q_))
1642 		return codel_getq(cl->codel_, cl->q_);
1643 #endif
1644 	return _getq(cl->q_);
1645 }
1646 
1647 static mbuf_t *
1648 _rmc_pollq(rm_class_t *cl)
1649 {
1650 	return qhead(cl->q_);
1651 }
1652 
1653 #ifdef CBQ_TRACE
1654 
1655 struct cbqtrace		 cbqtrace_buffer[NCBQTRACE+1];
1656 struct cbqtrace		*cbqtrace_ptr = NULL;
1657 int			 cbqtrace_count;
1658 
1659 /*
1660  * DDB hook to trace cbq events:
1661  *  the last 1024 events are held in a circular buffer.
1662  *  use "call cbqtrace_dump(N)" to display 20 events from Nth event.
1663  */
1664 void cbqtrace_dump(int);
1665 static char *rmc_funcname(void *);
1666 
1667 static struct rmc_funcs {
1668 	void	*func;
1669 	char	*name;
1670 } rmc_funcs[] =
1671 {
1672 	rmc_init,		"rmc_init",
1673 	rmc_queue_packet,	"rmc_queue_packet",
1674 	rmc_under_limit,	"rmc_under_limit",
1675 	rmc_update_class_util,	"rmc_update_class_util",
1676 	rmc_delay_action,	"rmc_delay_action",
1677 	rmc_restart,		"rmc_restart",
1678 	_rmc_wrr_dequeue_next,	"_rmc_wrr_dequeue_next",
1679 	NULL,			NULL
1680 };
1681 
1682 static char *rmc_funcname(void *func)
1683 {
1684 	struct rmc_funcs *fp;
1685 
1686 	for (fp = rmc_funcs; fp->func != NULL; fp++)
1687 		if (fp->func == func)
1688 			return (fp->name);
1689 	return ("unknown");
1690 }
1691 
1692 void cbqtrace_dump(int counter)
1693 {
1694 	int	 i, *p;
1695 	char	*cp;
1696 
1697 	counter = counter % NCBQTRACE;
1698 	p = (int *)&cbqtrace_buffer[counter];
1699 
1700 	for (i=0; i<20; i++) {
1701 		printf("[0x%x] ", *p++);
1702 		printf("%s: ", rmc_funcname((void *)*p++));
1703 		cp = (char *)p++;
1704 		printf("%c%c%c%c: ", cp[0], cp[1], cp[2], cp[3]);
1705 		printf("%d\n",*p++);
1706 
1707 		if (p >= (int *)&cbqtrace_buffer[NCBQTRACE])
1708 			p = (int *)cbqtrace_buffer;
1709 	}
1710 }
1711 #endif /* CBQ_TRACE */
1712 #endif /* ALTQ_CBQ */
1713 
1714 #if defined(ALTQ_CBQ) || defined(ALTQ_RED) || defined(ALTQ_RIO) || \
1715     defined(ALTQ_HFSC) || defined(ALTQ_PRIQ) || defined(ALTQ_CODEL)
1716 #if !defined(__GNUC__) || defined(ALTQ_DEBUG)
1717 
1718 void
1719 _addq(class_queue_t *q, mbuf_t *m)
1720 {
1721         mbuf_t	*m0;
1722 
1723 	if ((m0 = qtail(q)) != NULL)
1724 		m->m_nextpkt = m0->m_nextpkt;
1725 	else
1726 		m0 = m;
1727 	m0->m_nextpkt = m;
1728 	qtail(q) = m;
1729 	qlen(q)++;
1730 }
1731 
1732 mbuf_t *
1733 _getq(class_queue_t *q)
1734 {
1735 	mbuf_t	*m, *m0;
1736 
1737 	if ((m = qtail(q)) == NULL)
1738 		return (NULL);
1739 	if ((m0 = m->m_nextpkt) != m)
1740 		m->m_nextpkt = m0->m_nextpkt;
1741 	else {
1742 		ASSERT(qlen(q) == 1);
1743 		qtail(q) = NULL;
1744 	}
1745 	qlen(q)--;
1746 	m0->m_nextpkt = NULL;
1747 	return (m0);
1748 }
1749 
1750 /* drop a packet at the tail of the queue */
1751 mbuf_t *
1752 _getq_tail(class_queue_t *q)
1753 {
1754 	mbuf_t	*m, *m0, *prev;
1755 
1756 	if ((m = m0 = qtail(q)) == NULL)
1757 		return NULL;
1758 	do {
1759 		prev = m0;
1760 		m0 = m0->m_nextpkt;
1761 	} while (m0 != m);
1762 	prev->m_nextpkt = m->m_nextpkt;
1763 	if (prev == m)  {
1764 		ASSERT(qlen(q) == 1);
1765 		qtail(q) = NULL;
1766 	} else
1767 		qtail(q) = prev;
1768 	qlen(q)--;
1769 	m->m_nextpkt = NULL;
1770 	return (m);
1771 }
1772 
1773 /* randomly select a packet in the queue */
1774 mbuf_t *
1775 _getq_random(class_queue_t *q)
1776 {
1777 	struct mbuf	*m;
1778 	int		 i, n;
1779 
1780 	if ((m = qtail(q)) == NULL)
1781 		return NULL;
1782 	if (m->m_nextpkt == m) {
1783 		ASSERT(qlen(q) == 1);
1784 		qtail(q) = NULL;
1785 	} else {
1786 		struct mbuf *prev = NULL;
1787 
1788 		n = arc4random() % qlen(q) + 1;
1789 		for (i = 0; i < n; i++) {
1790 			prev = m;
1791 			m = m->m_nextpkt;
1792 		}
1793 		prev->m_nextpkt = m->m_nextpkt;
1794 		if (m == qtail(q))
1795 			qtail(q) = prev;
1796 	}
1797 	qlen(q)--;
1798 	m->m_nextpkt = NULL;
1799 	return (m);
1800 }
1801 
1802 void
1803 _removeq(class_queue_t *q, mbuf_t *m)
1804 {
1805 	mbuf_t	*m0, *prev;
1806 
1807 	m0 = qtail(q);
1808 	do {
1809 		prev = m0;
1810 		m0 = m0->m_nextpkt;
1811 	} while (m0 != m);
1812 	prev->m_nextpkt = m->m_nextpkt;
1813 	if (prev == m)
1814 		qtail(q) = NULL;
1815 	else if (qtail(q) == m)
1816 		qtail(q) = prev;
1817 	qlen(q)--;
1818 }
1819 
1820 void
1821 _flushq(class_queue_t *q)
1822 {
1823 	mbuf_t *m;
1824 
1825 	while ((m = _getq(q)) != NULL)
1826 		m_freem(m);
1827 	ASSERT(qlen(q) == 0);
1828 }
1829 
1830 #endif /* !__GNUC__ || ALTQ_DEBUG */
1831 #endif /* ALTQ_CBQ || ALTQ_RED || ALTQ_RIO || ALTQ_HFSC || ALTQ_PRIQ */
1832