xref: /freebsd/sys/net/altq/altq_hfsc.c (revision 81ad626541db97eb356e2c1d4a20eb2a26a766ab)
1 /*-
2  * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
3  *
4  * Permission to use, copy, modify, and distribute this software and
5  * its documentation is hereby granted (including for commercial or
6  * for-profit use), provided that both the copyright notice and this
7  * permission notice appear in all copies of the software, derivative
8  * works, or modified versions, and any portions thereof.
9  *
10  * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
11  * WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON PROVIDES THIS
12  * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
13  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
14  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
15  * DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
16  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
17  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
18  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
19  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
20  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
22  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
23  * DAMAGE.
24  *
25  * Carnegie Mellon encourages (but does not require) users of this
26  * software to return any improvements or extensions that they make,
27  * and to grant Carnegie Mellon the rights to redistribute these
28  * changes without encumbrance.
29  *
30  * $KAME: altq_hfsc.c,v 1.24 2003/12/05 05:40:46 kjc Exp $
31  * $FreeBSD$
32  */
33 /*
34  * H-FSC is described in Proceedings of SIGCOMM'97,
35  * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing,
36  * Real-Time and Priority Service"
37  * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng.
38  *
39  * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing.
40  * when a class has an upperlimit, the fit-time is computed from the
41  * upperlimit service curve.  the link-sharing scheduler does not schedule
42  * a class whose fit-time exceeds the current time.
43  */
44 
45 #include "opt_altq.h"
46 #include "opt_inet.h"
47 #include "opt_inet6.h"
48 
49 #ifdef ALTQ_HFSC  /* hfsc is enabled by ALTQ_HFSC option in opt_altq.h */
50 
51 #include <sys/param.h>
52 #include <sys/malloc.h>
53 #include <sys/mbuf.h>
54 #include <sys/socket.h>
55 #include <sys/systm.h>
56 #include <sys/errno.h>
57 #include <sys/queue.h>
58 #if 1 /* ALTQ3_COMPAT */
59 #include <sys/sockio.h>
60 #include <sys/proc.h>
61 #include <sys/kernel.h>
62 #endif /* ALTQ3_COMPAT */
63 
64 #include <net/if.h>
65 #include <net/if_var.h>
66 #include <net/if_private.h>
67 #include <netinet/in.h>
68 
69 #include <netpfil/pf/pf.h>
70 #include <netpfil/pf/pf_altq.h>
71 #include <netpfil/pf/pf_mtag.h>
72 #include <net/altq/altq.h>
73 #include <net/altq/altq_hfsc.h>
74 
75 /*
76  * function prototypes
77  */
78 static int			 hfsc_clear_interface(struct hfsc_if *);
79 static int			 hfsc_request(struct ifaltq *, int, void *);
80 static void			 hfsc_purge(struct hfsc_if *);
81 static struct hfsc_class	*hfsc_class_create(struct hfsc_if *,
82     struct service_curve *, struct service_curve *, struct service_curve *,
83     struct hfsc_class *, int, int, int);
84 static int			 hfsc_class_destroy(struct hfsc_class *);
85 static struct hfsc_class	*hfsc_nextclass(struct hfsc_class *);
86 static int			 hfsc_enqueue(struct ifaltq *, struct mbuf *,
87 				    struct altq_pktattr *);
88 static struct mbuf		*hfsc_dequeue(struct ifaltq *, int);
89 
90 static int		 hfsc_addq(struct hfsc_class *, struct mbuf *);
91 static struct mbuf	*hfsc_getq(struct hfsc_class *);
92 static struct mbuf	*hfsc_pollq(struct hfsc_class *);
93 static void		 hfsc_purgeq(struct hfsc_class *);
94 
95 static void		 update_cfmin(struct hfsc_class *);
96 static void		 set_active(struct hfsc_class *, int);
97 static void		 set_passive(struct hfsc_class *);
98 
99 static void		 init_ed(struct hfsc_class *, int);
100 static void		 update_ed(struct hfsc_class *, int);
101 static void		 update_d(struct hfsc_class *, int);
102 static void		 init_vf(struct hfsc_class *, int);
103 static void		 update_vf(struct hfsc_class *, int, u_int64_t);
104 static void		 ellist_insert(struct hfsc_class *);
105 static void		 ellist_remove(struct hfsc_class *);
106 static void		 ellist_update(struct hfsc_class *);
107 struct hfsc_class	*hfsc_get_mindl(struct hfsc_if *, u_int64_t);
108 static void		 actlist_insert(struct hfsc_class *);
109 static void		 actlist_remove(struct hfsc_class *);
110 static void		 actlist_update(struct hfsc_class *);
111 
112 static struct hfsc_class	*actlist_firstfit(struct hfsc_class *,
113 				    u_int64_t);
114 
115 static __inline u_int64_t	seg_x2y(u_int64_t, u_int64_t);
116 static __inline u_int64_t	seg_y2x(u_int64_t, u_int64_t);
117 static __inline u_int64_t	m2sm(u_int64_t);
118 static __inline u_int64_t	m2ism(u_int64_t);
119 static __inline u_int64_t	d2dx(u_int);
120 static u_int64_t		sm2m(u_int64_t);
121 static u_int			dx2d(u_int64_t);
122 
123 static void		sc2isc(struct service_curve *, struct internal_sc *);
124 static void		rtsc_init(struct runtime_sc *, struct internal_sc *,
125 			    u_int64_t, u_int64_t);
126 static u_int64_t	rtsc_y2x(struct runtime_sc *, u_int64_t);
127 static u_int64_t	rtsc_x2y(struct runtime_sc *, u_int64_t);
128 static void		rtsc_min(struct runtime_sc *, struct internal_sc *,
129 			    u_int64_t, u_int64_t);
130 
131 static void			 get_class_stats_v0(struct hfsc_classstats_v0 *,
132 				    struct hfsc_class *);
133 static void			 get_class_stats_v1(struct hfsc_classstats_v1 *,
134 				    struct hfsc_class *);
135 static struct hfsc_class	*clh_to_clp(struct hfsc_if *, u_int32_t);
136 
137 /*
138  * macros
139  */
140 #define	is_a_parent_class(cl)	((cl)->cl_children != NULL)
141 
142 #define	HT_INFINITY	0xffffffffffffffffULL	/* infinite time value */
143 
144 int
145 hfsc_pfattach(struct pf_altq *a)
146 {
147 	struct ifnet *ifp;
148 	int s, error;
149 
150 	if ((ifp = ifunit(a->ifname)) == NULL || a->altq_disc == NULL)
151 		return (EINVAL);
152 	s = splnet();
153 	error = altq_attach(&ifp->if_snd, ALTQT_HFSC, a->altq_disc,
154 	    hfsc_enqueue, hfsc_dequeue, hfsc_request);
155 	splx(s);
156 	return (error);
157 }
158 
159 int
160 hfsc_add_altq(struct ifnet *ifp, struct pf_altq *a)
161 {
162 	struct hfsc_if *hif;
163 
164 	if (ifp == NULL)
165 		return (EINVAL);
166 	if (!ALTQ_IS_READY(&ifp->if_snd))
167 		return (ENODEV);
168 
169 	hif = malloc(sizeof(struct hfsc_if), M_DEVBUF, M_NOWAIT | M_ZERO);
170 	if (hif == NULL)
171 		return (ENOMEM);
172 
173 	TAILQ_INIT(&hif->hif_eligible);
174 	hif->hif_ifq = &ifp->if_snd;
175 
176 	/* keep the state in pf_altq */
177 	a->altq_disc = hif;
178 
179 	return (0);
180 }
181 
182 int
183 hfsc_remove_altq(struct pf_altq *a)
184 {
185 	struct hfsc_if *hif;
186 
187 	if ((hif = a->altq_disc) == NULL)
188 		return (EINVAL);
189 	a->altq_disc = NULL;
190 
191 	(void)hfsc_clear_interface(hif);
192 	(void)hfsc_class_destroy(hif->hif_rootclass);
193 
194 	free(hif, M_DEVBUF);
195 
196 	return (0);
197 }
198 
199 int
200 hfsc_add_queue(struct pf_altq *a)
201 {
202 	struct hfsc_if *hif;
203 	struct hfsc_class *cl, *parent;
204 	struct hfsc_opts_v1 *opts;
205 	struct service_curve rtsc, lssc, ulsc;
206 
207 	if ((hif = a->altq_disc) == NULL)
208 		return (EINVAL);
209 
210 	opts = &a->pq_u.hfsc_opts;
211 
212 	if (a->parent_qid == HFSC_NULLCLASS_HANDLE &&
213 	    hif->hif_rootclass == NULL)
214 		parent = NULL;
215 	else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL)
216 		return (EINVAL);
217 
218 	if (a->qid == 0)
219 		return (EINVAL);
220 
221 	if (clh_to_clp(hif, a->qid) != NULL)
222 		return (EBUSY);
223 
224 	rtsc.m1 = opts->rtsc_m1;
225 	rtsc.d  = opts->rtsc_d;
226 	rtsc.m2 = opts->rtsc_m2;
227 	lssc.m1 = opts->lssc_m1;
228 	lssc.d  = opts->lssc_d;
229 	lssc.m2 = opts->lssc_m2;
230 	ulsc.m1 = opts->ulsc_m1;
231 	ulsc.d  = opts->ulsc_d;
232 	ulsc.m2 = opts->ulsc_m2;
233 
234 	cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc,
235 	    parent, a->qlimit, opts->flags, a->qid);
236 	if (cl == NULL)
237 		return (ENOMEM);
238 
239 	return (0);
240 }
241 
242 int
243 hfsc_remove_queue(struct pf_altq *a)
244 {
245 	struct hfsc_if *hif;
246 	struct hfsc_class *cl;
247 
248 	if ((hif = a->altq_disc) == NULL)
249 		return (EINVAL);
250 
251 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
252 		return (EINVAL);
253 
254 	return (hfsc_class_destroy(cl));
255 }
256 
257 int
258 hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes, int version)
259 {
260 	struct hfsc_if *hif;
261 	struct hfsc_class *cl;
262 	union {
263 		struct hfsc_classstats_v0 v0;
264 		struct hfsc_classstats_v1 v1;
265 	} stats;
266 	size_t stats_size;
267 	int error = 0;
268 
269 	if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL)
270 		return (EBADF);
271 
272 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
273 		return (EINVAL);
274 
275 	if (version > HFSC_STATS_VERSION)
276 		return (EINVAL);
277 
278 	memset(&stats, 0, sizeof(stats));
279 	switch (version) {
280 	case 0:
281 		get_class_stats_v0(&stats.v0, cl);
282 		stats_size = sizeof(struct hfsc_classstats_v0);
283 		break;
284 	case 1:
285 		get_class_stats_v1(&stats.v1, cl);
286 		stats_size = sizeof(struct hfsc_classstats_v1);
287 		break;
288 	}
289 
290 	if (*nbytes < stats_size)
291 		return (EINVAL);
292 
293 	if ((error = copyout((caddr_t)&stats, ubuf, stats_size)) != 0)
294 		return (error);
295 	*nbytes = stats_size;
296 	return (0);
297 }
298 
299 /*
300  * bring the interface back to the initial state by discarding
301  * all the filters and classes except the root class.
302  */
303 static int
304 hfsc_clear_interface(struct hfsc_if *hif)
305 {
306 	struct hfsc_class	*cl;
307 
308 	/* clear out the classes */
309 	while (hif->hif_rootclass != NULL &&
310 	    (cl = hif->hif_rootclass->cl_children) != NULL) {
311 		/*
312 		 * remove the first leaf class found in the hierarchy
313 		 * then start over
314 		 */
315 		for (; cl != NULL; cl = hfsc_nextclass(cl)) {
316 			if (!is_a_parent_class(cl)) {
317 				(void)hfsc_class_destroy(cl);
318 				break;
319 			}
320 		}
321 	}
322 
323 	return (0);
324 }
325 
326 static int
327 hfsc_request(struct ifaltq *ifq, int req, void *arg)
328 {
329 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
330 
331 	IFQ_LOCK_ASSERT(ifq);
332 
333 	switch (req) {
334 	case ALTRQ_PURGE:
335 		hfsc_purge(hif);
336 		break;
337 	}
338 	return (0);
339 }
340 
341 /* discard all the queued packets on the interface */
342 static void
343 hfsc_purge(struct hfsc_if *hif)
344 {
345 	struct hfsc_class *cl;
346 
347 	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
348 		if (!qempty(cl->cl_q))
349 			hfsc_purgeq(cl);
350 	if (ALTQ_IS_ENABLED(hif->hif_ifq))
351 		hif->hif_ifq->ifq_len = 0;
352 }
353 
354 struct hfsc_class *
355 hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc,
356     struct service_curve *fsc, struct service_curve *usc,
357     struct hfsc_class *parent, int qlimit, int flags, int qid)
358 {
359 	struct hfsc_class *cl, *p;
360 	int i, s;
361 
362 	if (hif->hif_classes >= HFSC_MAX_CLASSES)
363 		return (NULL);
364 
365 #ifndef ALTQ_RED
366 	if (flags & HFCF_RED) {
367 #ifdef ALTQ_DEBUG
368 		printf("hfsc_class_create: RED not configured for HFSC!\n");
369 #endif
370 		return (NULL);
371 	}
372 #endif
373 #ifndef ALTQ_CODEL
374 	if (flags & HFCF_CODEL) {
375 #ifdef ALTQ_DEBUG
376 		printf("hfsc_class_create: CODEL not configured for HFSC!\n");
377 #endif
378 		return (NULL);
379 	}
380 #endif
381 
382 	cl = malloc(sizeof(struct hfsc_class), M_DEVBUF, M_NOWAIT | M_ZERO);
383 	if (cl == NULL)
384 		return (NULL);
385 
386 	cl->cl_q = malloc(sizeof(class_queue_t), M_DEVBUF, M_NOWAIT | M_ZERO);
387 	if (cl->cl_q == NULL)
388 		goto err_ret;
389 
390 	TAILQ_INIT(&cl->cl_actc);
391 
392 	if (qlimit == 0)
393 		qlimit = 50;  /* use default */
394 	qlimit(cl->cl_q) = qlimit;
395 	qtype(cl->cl_q) = Q_DROPTAIL;
396 	qlen(cl->cl_q) = 0;
397 	qsize(cl->cl_q) = 0;
398 	cl->cl_flags = flags;
399 #ifdef ALTQ_RED
400 	if (flags & (HFCF_RED|HFCF_RIO)) {
401 		int red_flags, red_pkttime;
402 		u_int m2;
403 
404 		m2 = 0;
405 		if (rsc != NULL && rsc->m2 > m2)
406 			m2 = rsc->m2;
407 		if (fsc != NULL && fsc->m2 > m2)
408 			m2 = fsc->m2;
409 		if (usc != NULL && usc->m2 > m2)
410 			m2 = usc->m2;
411 
412 		red_flags = 0;
413 		if (flags & HFCF_ECN)
414 			red_flags |= REDF_ECN;
415 #ifdef ALTQ_RIO
416 		if (flags & HFCF_CLEARDSCP)
417 			red_flags |= RIOF_CLEARDSCP;
418 #endif
419 		if (m2 < 8)
420 			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
421 		else
422 			red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu
423 				* 1000 * 1000 * 1000 / (m2 / 8);
424 		if (flags & HFCF_RED) {
425 			cl->cl_red = red_alloc(0, 0,
426 			    qlimit(cl->cl_q) * 10/100,
427 			    qlimit(cl->cl_q) * 30/100,
428 			    red_flags, red_pkttime);
429 			if (cl->cl_red != NULL)
430 				qtype(cl->cl_q) = Q_RED;
431 		}
432 #ifdef ALTQ_RIO
433 		else {
434 			cl->cl_red = (red_t *)rio_alloc(0, NULL,
435 			    red_flags, red_pkttime);
436 			if (cl->cl_red != NULL)
437 				qtype(cl->cl_q) = Q_RIO;
438 		}
439 #endif
440 	}
441 #endif /* ALTQ_RED */
442 #ifdef ALTQ_CODEL
443 	if (flags & HFCF_CODEL) {
444 		cl->cl_codel = codel_alloc(5, 100, 0);
445 		if (cl->cl_codel != NULL)
446 			qtype(cl->cl_q) = Q_CODEL;
447 	}
448 #endif
449 
450 	if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
451 		cl->cl_rsc = malloc(sizeof(struct internal_sc),
452 		    M_DEVBUF, M_NOWAIT);
453 		if (cl->cl_rsc == NULL)
454 			goto err_ret;
455 		sc2isc(rsc, cl->cl_rsc);
456 		rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0);
457 		rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0);
458 	}
459 	if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) {
460 		cl->cl_fsc = malloc(sizeof(struct internal_sc),
461 		    M_DEVBUF, M_NOWAIT);
462 		if (cl->cl_fsc == NULL)
463 			goto err_ret;
464 		sc2isc(fsc, cl->cl_fsc);
465 		rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0);
466 	}
467 	if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) {
468 		cl->cl_usc = malloc(sizeof(struct internal_sc),
469 		    M_DEVBUF, M_NOWAIT);
470 		if (cl->cl_usc == NULL)
471 			goto err_ret;
472 		sc2isc(usc, cl->cl_usc);
473 		rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0);
474 	}
475 
476 	cl->cl_id = hif->hif_classid++;
477 	cl->cl_handle = qid;
478 	cl->cl_hif = hif;
479 	cl->cl_parent = parent;
480 
481 	s = splnet();
482 	IFQ_LOCK(hif->hif_ifq);
483 	hif->hif_classes++;
484 
485 	/*
486 	 * find a free slot in the class table.  if the slot matching
487 	 * the lower bits of qid is free, use this slot.  otherwise,
488 	 * use the first free slot.
489 	 */
490 	i = qid % HFSC_MAX_CLASSES;
491 	if (hif->hif_class_tbl[i] == NULL)
492 		hif->hif_class_tbl[i] = cl;
493 	else {
494 		for (i = 0; i < HFSC_MAX_CLASSES; i++)
495 			if (hif->hif_class_tbl[i] == NULL) {
496 				hif->hif_class_tbl[i] = cl;
497 				break;
498 			}
499 		if (i == HFSC_MAX_CLASSES) {
500 			IFQ_UNLOCK(hif->hif_ifq);
501 			splx(s);
502 			goto err_ret;
503 		}
504 	}
505 	cl->cl_slot = i;
506 
507 	if (flags & HFCF_DEFAULTCLASS)
508 		hif->hif_defaultclass = cl;
509 
510 	if (parent == NULL) {
511 		/* this is root class */
512 		hif->hif_rootclass = cl;
513 	} else {
514 		/* add this class to the children list of the parent */
515 		if ((p = parent->cl_children) == NULL)
516 			parent->cl_children = cl;
517 		else {
518 			/* Put new class at beginning of list */
519 			cl->cl_siblings = parent->cl_children;
520 			parent->cl_children = cl;
521 		}
522 	}
523 	IFQ_UNLOCK(hif->hif_ifq);
524 	splx(s);
525 
526 	return (cl);
527 
528  err_ret:
529 	if (cl->cl_red != NULL) {
530 #ifdef ALTQ_RIO
531 		if (q_is_rio(cl->cl_q))
532 			rio_destroy((rio_t *)cl->cl_red);
533 #endif
534 #ifdef ALTQ_RED
535 		if (q_is_red(cl->cl_q))
536 			red_destroy(cl->cl_red);
537 #endif
538 #ifdef ALTQ_CODEL
539 		if (q_is_codel(cl->cl_q))
540 			codel_destroy(cl->cl_codel);
541 #endif
542 	}
543 	if (cl->cl_fsc != NULL)
544 		free(cl->cl_fsc, M_DEVBUF);
545 	if (cl->cl_rsc != NULL)
546 		free(cl->cl_rsc, M_DEVBUF);
547 	if (cl->cl_usc != NULL)
548 		free(cl->cl_usc, M_DEVBUF);
549 	if (cl->cl_q != NULL)
550 		free(cl->cl_q, M_DEVBUF);
551 	free(cl, M_DEVBUF);
552 	return (NULL);
553 }
554 
555 static int
556 hfsc_class_destroy(struct hfsc_class *cl)
557 {
558 	int s;
559 
560 	if (cl == NULL)
561 		return (0);
562 
563 	if (is_a_parent_class(cl))
564 		return (EBUSY);
565 
566 	s = splnet();
567 	IFQ_LOCK(cl->cl_hif->hif_ifq);
568 
569 	if (!qempty(cl->cl_q))
570 		hfsc_purgeq(cl);
571 
572 	if (cl->cl_parent == NULL) {
573 		/* this is root class */
574 	} else {
575 		struct hfsc_class *p = cl->cl_parent->cl_children;
576 
577 		if (p == cl)
578 			cl->cl_parent->cl_children = cl->cl_siblings;
579 		else do {
580 			if (p->cl_siblings == cl) {
581 				p->cl_siblings = cl->cl_siblings;
582 				break;
583 			}
584 		} while ((p = p->cl_siblings) != NULL);
585 		ASSERT(p != NULL);
586 	}
587 
588 	cl->cl_hif->hif_class_tbl[cl->cl_slot] = NULL;
589 	cl->cl_hif->hif_classes--;
590 	IFQ_UNLOCK(cl->cl_hif->hif_ifq);
591 	splx(s);
592 
593 	if (cl->cl_red != NULL) {
594 #ifdef ALTQ_RIO
595 		if (q_is_rio(cl->cl_q))
596 			rio_destroy((rio_t *)cl->cl_red);
597 #endif
598 #ifdef ALTQ_RED
599 		if (q_is_red(cl->cl_q))
600 			red_destroy(cl->cl_red);
601 #endif
602 #ifdef ALTQ_CODEL
603 		if (q_is_codel(cl->cl_q))
604 			codel_destroy(cl->cl_codel);
605 #endif
606 	}
607 
608 	IFQ_LOCK(cl->cl_hif->hif_ifq);
609 	if (cl == cl->cl_hif->hif_rootclass)
610 		cl->cl_hif->hif_rootclass = NULL;
611 	if (cl == cl->cl_hif->hif_defaultclass)
612 		cl->cl_hif->hif_defaultclass = NULL;
613 	IFQ_UNLOCK(cl->cl_hif->hif_ifq);
614 
615 	if (cl->cl_usc != NULL)
616 		free(cl->cl_usc, M_DEVBUF);
617 	if (cl->cl_fsc != NULL)
618 		free(cl->cl_fsc, M_DEVBUF);
619 	if (cl->cl_rsc != NULL)
620 		free(cl->cl_rsc, M_DEVBUF);
621 	free(cl->cl_q, M_DEVBUF);
622 	free(cl, M_DEVBUF);
623 
624 	return (0);
625 }
626 
627 /*
628  * hfsc_nextclass returns the next class in the tree.
629  *   usage:
630  *	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
631  *		do_something;
632  */
633 static struct hfsc_class *
634 hfsc_nextclass(struct hfsc_class *cl)
635 {
636 	if (cl->cl_children != NULL)
637 		cl = cl->cl_children;
638 	else if (cl->cl_siblings != NULL)
639 		cl = cl->cl_siblings;
640 	else {
641 		while ((cl = cl->cl_parent) != NULL)
642 			if (cl->cl_siblings) {
643 				cl = cl->cl_siblings;
644 				break;
645 			}
646 	}
647 
648 	return (cl);
649 }
650 
651 /*
652  * hfsc_enqueue is an enqueue function to be registered to
653  * (*altq_enqueue) in struct ifaltq.
654  */
655 static int
656 hfsc_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr)
657 {
658 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
659 	struct hfsc_class *cl;
660 	struct pf_mtag *t;
661 	int len;
662 
663 	IFQ_LOCK_ASSERT(ifq);
664 
665 	/* grab class set by classifier */
666 	if ((m->m_flags & M_PKTHDR) == 0) {
667 		/* should not happen */
668 		printf("altq: packet for %s does not have pkthdr\n",
669 		    ifq->altq_ifp->if_xname);
670 		m_freem(m);
671 		return (ENOBUFS);
672 	}
673 	cl = NULL;
674 	if ((t = pf_find_mtag(m)) != NULL)
675 		cl = clh_to_clp(hif, t->qid);
676 	if (cl == NULL || is_a_parent_class(cl)) {
677 		cl = hif->hif_defaultclass;
678 		if (cl == NULL) {
679 			m_freem(m);
680 			return (ENOBUFS);
681 		}
682 	}
683 	cl->cl_pktattr = NULL;
684 	len = m_pktlen(m);
685 	if (hfsc_addq(cl, m) != 0) {
686 		/* drop occurred.  mbuf was freed in hfsc_addq. */
687 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len);
688 		return (ENOBUFS);
689 	}
690 	IFQ_INC_LEN(ifq);
691 	cl->cl_hif->hif_packets++;
692 
693 	/* successfully queued. */
694 	if (qlen(cl->cl_q) == 1)
695 		set_active(cl, m_pktlen(m));
696 
697 	return (0);
698 }
699 
700 /*
701  * hfsc_dequeue is a dequeue function to be registered to
702  * (*altq_dequeue) in struct ifaltq.
703  *
704  * note: ALTDQ_POLL returns the next packet without removing the packet
705  *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
706  *	ALTDQ_REMOVE must return the same packet if called immediately
707  *	after ALTDQ_POLL.
708  */
709 static struct mbuf *
710 hfsc_dequeue(struct ifaltq *ifq, int op)
711 {
712 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
713 	struct hfsc_class *cl;
714 	struct mbuf *m;
715 	int len, next_len;
716 	int realtime = 0;
717 	u_int64_t cur_time;
718 
719 	IFQ_LOCK_ASSERT(ifq);
720 
721 	if (hif->hif_packets == 0)
722 		/* no packet in the tree */
723 		return (NULL);
724 
725 	cur_time = read_machclk();
726 
727 	if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) {
728 		cl = hif->hif_pollcache;
729 		hif->hif_pollcache = NULL;
730 		/* check if the class was scheduled by real-time criteria */
731 		if (cl->cl_rsc != NULL)
732 			realtime = (cl->cl_e <= cur_time);
733 	} else {
734 		/*
735 		 * if there are eligible classes, use real-time criteria.
736 		 * find the class with the minimum deadline among
737 		 * the eligible classes.
738 		 */
739 		if ((cl = hfsc_get_mindl(hif, cur_time))
740 		    != NULL) {
741 			realtime = 1;
742 		} else {
743 #ifdef ALTQ_DEBUG
744 			int fits = 0;
745 #endif
746 			/*
747 			 * use link-sharing criteria
748 			 * get the class with the minimum vt in the hierarchy
749 			 */
750 			cl = hif->hif_rootclass;
751 			while (is_a_parent_class(cl)) {
752 				cl = actlist_firstfit(cl, cur_time);
753 				if (cl == NULL) {
754 #ifdef ALTQ_DEBUG
755 					if (fits > 0)
756 						printf("%d fit but none found\n",fits);
757 #endif
758 					return (NULL);
759 				}
760 				/*
761 				 * update parent's cl_cvtmin.
762 				 * don't update if the new vt is smaller.
763 				 */
764 				if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
765 					cl->cl_parent->cl_cvtmin = cl->cl_vt;
766 #ifdef ALTQ_DEBUG
767 				fits++;
768 #endif
769 			}
770 		}
771 
772 		if (op == ALTDQ_POLL) {
773 			hif->hif_pollcache = cl;
774 			m = hfsc_pollq(cl);
775 			return (m);
776 		}
777 	}
778 
779 	m = hfsc_getq(cl);
780 	if (m == NULL)
781 		panic("hfsc_dequeue:");
782 	len = m_pktlen(m);
783 	cl->cl_hif->hif_packets--;
784 	IFQ_DEC_LEN(ifq);
785 	PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len);
786 
787 	update_vf(cl, len, cur_time);
788 	if (realtime)
789 		cl->cl_cumul += len;
790 
791 	if (!qempty(cl->cl_q)) {
792 		if (cl->cl_rsc != NULL) {
793 			/* update ed */
794 			next_len = m_pktlen(qhead(cl->cl_q));
795 
796 			if (realtime)
797 				update_ed(cl, next_len);
798 			else
799 				update_d(cl, next_len);
800 		}
801 	} else {
802 		/* the class becomes passive */
803 		set_passive(cl);
804 	}
805 
806 	return (m);
807 }
808 
809 static int
810 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
811 {
812 
813 #ifdef ALTQ_RIO
814 	if (q_is_rio(cl->cl_q))
815 		return rio_addq((rio_t *)cl->cl_red, cl->cl_q,
816 				m, cl->cl_pktattr);
817 #endif
818 #ifdef ALTQ_RED
819 	if (q_is_red(cl->cl_q))
820 		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
821 #endif
822 #ifdef ALTQ_CODEL
823 	if (q_is_codel(cl->cl_q))
824 		return codel_addq(cl->cl_codel, cl->cl_q, m);
825 #endif
826 	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
827 		m_freem(m);
828 		return (-1);
829 	}
830 
831 	if (cl->cl_flags & HFCF_CLEARDSCP)
832 		write_dsfield(m, cl->cl_pktattr, 0);
833 
834 	_addq(cl->cl_q, m);
835 
836 	return (0);
837 }
838 
839 static struct mbuf *
840 hfsc_getq(struct hfsc_class *cl)
841 {
842 #ifdef ALTQ_RIO
843 	if (q_is_rio(cl->cl_q))
844 		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
845 #endif
846 #ifdef ALTQ_RED
847 	if (q_is_red(cl->cl_q))
848 		return red_getq(cl->cl_red, cl->cl_q);
849 #endif
850 #ifdef ALTQ_CODEL
851 	if (q_is_codel(cl->cl_q))
852 		return codel_getq(cl->cl_codel, cl->cl_q);
853 #endif
854 	return _getq(cl->cl_q);
855 }
856 
857 static struct mbuf *
858 hfsc_pollq(struct hfsc_class *cl)
859 {
860 	return qhead(cl->cl_q);
861 }
862 
863 static void
864 hfsc_purgeq(struct hfsc_class *cl)
865 {
866 	struct mbuf *m;
867 
868 	if (qempty(cl->cl_q))
869 		return;
870 
871 	while ((m = _getq(cl->cl_q)) != NULL) {
872 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m));
873 		m_freem(m);
874 		cl->cl_hif->hif_packets--;
875 		IFQ_DEC_LEN(cl->cl_hif->hif_ifq);
876 	}
877 	ASSERT(qlen(cl->cl_q) == 0);
878 
879 	update_vf(cl, 0, 0);	/* remove cl from the actlist */
880 	set_passive(cl);
881 }
882 
883 static void
884 set_active(struct hfsc_class *cl, int len)
885 {
886 	if (cl->cl_rsc != NULL)
887 		init_ed(cl, len);
888 	if (cl->cl_fsc != NULL)
889 		init_vf(cl, len);
890 
891 	cl->cl_stats.period++;
892 }
893 
894 static void
895 set_passive(struct hfsc_class *cl)
896 {
897 	if (cl->cl_rsc != NULL)
898 		ellist_remove(cl);
899 
900 	/*
901 	 * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
902 	 * needs to be called explicitly to remove a class from actlist
903 	 */
904 }
905 
906 static void
907 init_ed(struct hfsc_class *cl, int next_len)
908 {
909 	u_int64_t cur_time;
910 
911 	cur_time = read_machclk();
912 
913 	/* update the deadline curve */
914 	rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul);
915 
916 	/*
917 	 * update the eligible curve.
918 	 * for concave, it is equal to the deadline curve.
919 	 * for convex, it is a linear curve with slope m2.
920 	 */
921 	cl->cl_eligible = cl->cl_deadline;
922 	if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) {
923 		cl->cl_eligible.dx = 0;
924 		cl->cl_eligible.dy = 0;
925 	}
926 
927 	/* compute e and d */
928 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
929 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
930 
931 	ellist_insert(cl);
932 }
933 
934 static void
935 update_ed(struct hfsc_class *cl, int next_len)
936 {
937 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
938 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
939 
940 	ellist_update(cl);
941 }
942 
943 static void
944 update_d(struct hfsc_class *cl, int next_len)
945 {
946 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
947 }
948 
949 static void
950 init_vf(struct hfsc_class *cl, int len)
951 {
952 	struct hfsc_class *max_cl, *p;
953 	u_int64_t vt, f, cur_time;
954 	int go_active;
955 
956 	cur_time = 0;
957 	go_active = 1;
958 	for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) {
959 		if (go_active && cl->cl_nactive++ == 0)
960 			go_active = 1;
961 		else
962 			go_active = 0;
963 
964 		if (go_active) {
965 			max_cl = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead);
966 			if (max_cl != NULL) {
967 				/*
968 				 * set vt to the average of the min and max
969 				 * classes.  if the parent's period didn't
970 				 * change, don't decrease vt of the class.
971 				 */
972 				vt = max_cl->cl_vt;
973 				if (cl->cl_parent->cl_cvtmin != 0)
974 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
975 
976 				if (cl->cl_parent->cl_vtperiod !=
977 				    cl->cl_parentperiod || vt > cl->cl_vt)
978 					cl->cl_vt = vt;
979 			} else {
980 				/*
981 				 * first child for a new parent backlog period.
982 				 * add parent's cvtmax to vtoff of children
983 				 * to make a new vt (vtoff + vt) larger than
984 				 * the vt in the last period for all children.
985 				 */
986 				vt = cl->cl_parent->cl_cvtmax;
987 				for (p = cl->cl_parent->cl_children; p != NULL;
988 				     p = p->cl_siblings)
989 					p->cl_vtoff += vt;
990 				cl->cl_vt = 0;
991 				cl->cl_parent->cl_cvtmax = 0;
992 				cl->cl_parent->cl_cvtmin = 0;
993 			}
994 			cl->cl_initvt = cl->cl_vt;
995 
996 			/* update the virtual curve */
997 			vt = cl->cl_vt + cl->cl_vtoff;
998 			rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total);
999 			if (cl->cl_virtual.x == vt) {
1000 				cl->cl_virtual.x -= cl->cl_vtoff;
1001 				cl->cl_vtoff = 0;
1002 			}
1003 			cl->cl_vtadj = 0;
1004 
1005 			cl->cl_vtperiod++;  /* increment vt period */
1006 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
1007 			if (cl->cl_parent->cl_nactive == 0)
1008 				cl->cl_parentperiod++;
1009 			cl->cl_f = 0;
1010 
1011 			actlist_insert(cl);
1012 
1013 			if (cl->cl_usc != NULL) {
1014 				/* class has upper limit curve */
1015 				if (cur_time == 0)
1016 					cur_time = read_machclk();
1017 
1018 				/* update the ulimit curve */
1019 				rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time,
1020 				    cl->cl_total);
1021 				/* compute myf */
1022 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
1023 				    cl->cl_total);
1024 				cl->cl_myfadj = 0;
1025 			}
1026 		}
1027 
1028 		if (cl->cl_myf > cl->cl_cfmin)
1029 			f = cl->cl_myf;
1030 		else
1031 			f = cl->cl_cfmin;
1032 		if (f != cl->cl_f) {
1033 			cl->cl_f = f;
1034 			update_cfmin(cl->cl_parent);
1035 		}
1036 	}
1037 }
1038 
1039 static void
1040 update_vf(struct hfsc_class *cl, int len, u_int64_t cur_time)
1041 {
1042 	u_int64_t f, myf_bound, delta;
1043 	int go_passive;
1044 
1045 	go_passive = qempty(cl->cl_q);
1046 
1047 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
1048 		cl->cl_total += len;
1049 
1050 		if (cl->cl_fsc == NULL || cl->cl_nactive == 0)
1051 			continue;
1052 
1053 		if (go_passive && --cl->cl_nactive == 0)
1054 			go_passive = 1;
1055 		else
1056 			go_passive = 0;
1057 
1058 		if (go_passive) {
1059 			/* no more active child, going passive */
1060 
1061 			/* update cvtmax of the parent class */
1062 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
1063 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
1064 
1065 			/* remove this class from the vt list */
1066 			actlist_remove(cl);
1067 
1068 			update_cfmin(cl->cl_parent);
1069 
1070 			continue;
1071 		}
1072 
1073 		/*
1074 		 * update vt and f
1075 		 */
1076 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
1077 		    - cl->cl_vtoff + cl->cl_vtadj;
1078 
1079 		/*
1080 		 * if vt of the class is smaller than cvtmin,
1081 		 * the class was skipped in the past due to non-fit.
1082 		 * if so, we need to adjust vtadj.
1083 		 */
1084 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
1085 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
1086 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
1087 		}
1088 
1089 		/* update the vt list */
1090 		actlist_update(cl);
1091 
1092 		if (cl->cl_usc != NULL) {
1093 			cl->cl_myf = cl->cl_myfadj
1094 			    + rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
1095 
1096 			/*
1097 			 * if myf lags behind by more than one clock tick
1098 			 * from the current time, adjust myfadj to prevent
1099 			 * a rate-limited class from going greedy.
1100 			 * in a steady state under rate-limiting, myf
1101 			 * fluctuates within one clock tick.
1102 			 */
1103 			myf_bound = cur_time - machclk_per_tick;
1104 			if (cl->cl_myf < myf_bound) {
1105 				delta = cur_time - cl->cl_myf;
1106 				cl->cl_myfadj += delta;
1107 				cl->cl_myf += delta;
1108 			}
1109 		}
1110 
1111 		/* cl_f is max(cl_myf, cl_cfmin) */
1112 		if (cl->cl_myf > cl->cl_cfmin)
1113 			f = cl->cl_myf;
1114 		else
1115 			f = cl->cl_cfmin;
1116 		if (f != cl->cl_f) {
1117 			cl->cl_f = f;
1118 			update_cfmin(cl->cl_parent);
1119 		}
1120 	}
1121 }
1122 
1123 static void
1124 update_cfmin(struct hfsc_class *cl)
1125 {
1126 	struct hfsc_class *p;
1127 	u_int64_t cfmin;
1128 
1129 	if (TAILQ_EMPTY(&cl->cl_actc)) {
1130 		cl->cl_cfmin = 0;
1131 		return;
1132 	}
1133 	cfmin = HT_INFINITY;
1134 	TAILQ_FOREACH(p, &cl->cl_actc, cl_actlist) {
1135 		if (p->cl_f == 0) {
1136 			cl->cl_cfmin = 0;
1137 			return;
1138 		}
1139 		if (p->cl_f < cfmin)
1140 			cfmin = p->cl_f;
1141 	}
1142 	cl->cl_cfmin = cfmin;
1143 }
1144 
1145 /*
1146  * TAILQ based ellist and actlist implementation
1147  * (ion wanted to make a calendar queue based implementation)
1148  */
1149 /*
1150  * eligible list holds backlogged classes being sorted by their eligible times.
1151  * there is one eligible list per interface.
1152  */
1153 
1154 static void
1155 ellist_insert(struct hfsc_class *cl)
1156 {
1157 	struct hfsc_if	*hif = cl->cl_hif;
1158 	struct hfsc_class *p;
1159 
1160 	/* check the last entry first */
1161 	if ((p = TAILQ_LAST(&hif->hif_eligible, elighead)) == NULL ||
1162 	    p->cl_e <= cl->cl_e) {
1163 		TAILQ_INSERT_TAIL(&hif->hif_eligible, cl, cl_ellist);
1164 		return;
1165 	}
1166 
1167 	TAILQ_FOREACH(p, &hif->hif_eligible, cl_ellist) {
1168 		if (cl->cl_e < p->cl_e) {
1169 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1170 			return;
1171 		}
1172 	}
1173 	ASSERT(0); /* should not reach here */
1174 }
1175 
1176 static void
1177 ellist_remove(struct hfsc_class *cl)
1178 {
1179 	struct hfsc_if	*hif = cl->cl_hif;
1180 
1181 	TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist);
1182 }
1183 
1184 static void
1185 ellist_update(struct hfsc_class *cl)
1186 {
1187 	struct hfsc_if	*hif = cl->cl_hif;
1188 	struct hfsc_class *p, *last;
1189 
1190 	/*
1191 	 * the eligible time of a class increases monotonically.
1192 	 * if the next entry has a larger eligible time, nothing to do.
1193 	 */
1194 	p = TAILQ_NEXT(cl, cl_ellist);
1195 	if (p == NULL || cl->cl_e <= p->cl_e)
1196 		return;
1197 
1198 	/* check the last entry */
1199 	last = TAILQ_LAST(&hif->hif_eligible, elighead);
1200 	ASSERT(last != NULL);
1201 	if (last->cl_e <= cl->cl_e) {
1202 		TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist);
1203 		TAILQ_INSERT_TAIL(&hif->hif_eligible, cl, cl_ellist);
1204 		return;
1205 	}
1206 
1207 	/*
1208 	 * the new position must be between the next entry
1209 	 * and the last entry
1210 	 */
1211 	while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) {
1212 		if (cl->cl_e < p->cl_e) {
1213 			TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist);
1214 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1215 			return;
1216 		}
1217 	}
1218 	ASSERT(0); /* should not reach here */
1219 }
1220 
1221 /* find the class with the minimum deadline among the eligible classes */
1222 struct hfsc_class *
1223 hfsc_get_mindl(struct hfsc_if *hif, u_int64_t cur_time)
1224 {
1225 	struct hfsc_class *p, *cl = NULL;
1226 
1227 	TAILQ_FOREACH(p, &hif->hif_eligible, cl_ellist) {
1228 		if (p->cl_e > cur_time)
1229 			break;
1230 		if (cl == NULL || p->cl_d < cl->cl_d)
1231 			cl = p;
1232 	}
1233 	return (cl);
1234 }
1235 
1236 /*
1237  * active children list holds backlogged child classes being sorted
1238  * by their virtual time.
1239  * each intermediate class has one active children list.
1240  */
1241 
1242 static void
1243 actlist_insert(struct hfsc_class *cl)
1244 {
1245 	struct hfsc_class *p;
1246 
1247 	/* check the last entry first */
1248 	if ((p = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead)) == NULL
1249 	    || p->cl_vt <= cl->cl_vt) {
1250 		TAILQ_INSERT_TAIL(&cl->cl_parent->cl_actc, cl, cl_actlist);
1251 		return;
1252 	}
1253 
1254 	TAILQ_FOREACH(p, &cl->cl_parent->cl_actc, cl_actlist) {
1255 		if (cl->cl_vt < p->cl_vt) {
1256 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1257 			return;
1258 		}
1259 	}
1260 	ASSERT(0); /* should not reach here */
1261 }
1262 
1263 static void
1264 actlist_remove(struct hfsc_class *cl)
1265 {
1266 	TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist);
1267 }
1268 
1269 static void
1270 actlist_update(struct hfsc_class *cl)
1271 {
1272 	struct hfsc_class *p, *last;
1273 
1274 	/*
1275 	 * the virtual time of a class increases monotonically during its
1276 	 * backlogged period.
1277 	 * if the next entry has a larger virtual time, nothing to do.
1278 	 */
1279 	p = TAILQ_NEXT(cl, cl_actlist);
1280 	if (p == NULL || cl->cl_vt < p->cl_vt)
1281 		return;
1282 
1283 	/* check the last entry */
1284 	last = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead);
1285 	ASSERT(last != NULL);
1286 	if (last->cl_vt <= cl->cl_vt) {
1287 		TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist);
1288 		TAILQ_INSERT_TAIL(&cl->cl_parent->cl_actc, cl, cl_actlist);
1289 		return;
1290 	}
1291 
1292 	/*
1293 	 * the new position must be between the next entry
1294 	 * and the last entry
1295 	 */
1296 	while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) {
1297 		if (cl->cl_vt < p->cl_vt) {
1298 			TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist);
1299 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1300 			return;
1301 		}
1302 	}
1303 	ASSERT(0); /* should not reach here */
1304 }
1305 
1306 static struct hfsc_class *
1307 actlist_firstfit(struct hfsc_class *cl, u_int64_t cur_time)
1308 {
1309 	struct hfsc_class *p;
1310 
1311 	TAILQ_FOREACH(p, &cl->cl_actc, cl_actlist) {
1312 		if (p->cl_f <= cur_time)
1313 			return (p);
1314 	}
1315 	return (NULL);
1316 }
1317 
1318 /*
1319  * service curve support functions
1320  *
1321  *  external service curve parameters
1322  *	m: bits/sec
1323  *	d: msec
1324  *  internal service curve parameters
1325  *	sm: (bytes/machclk tick) << SM_SHIFT
1326  *	ism: (machclk ticks/byte) << ISM_SHIFT
1327  *	dx: machclk ticks
1328  *
1329  * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits.  we
1330  * should be able to handle 100K-100Gbps linkspeed with 256 MHz machclk
1331  * frequency and at least 3 effective digits in decimal.
1332  *
1333  */
1334 #define	SM_SHIFT	24
1335 #define	ISM_SHIFT	14
1336 
1337 #define	SM_MASK		((1LL << SM_SHIFT) - 1)
1338 #define	ISM_MASK	((1LL << ISM_SHIFT) - 1)
1339 
1340 static __inline u_int64_t
1341 seg_x2y(u_int64_t x, u_int64_t sm)
1342 {
1343 	u_int64_t y;
1344 
1345 	/*
1346 	 * compute
1347 	 *	y = x * sm >> SM_SHIFT
1348 	 * but divide it for the upper and lower bits to avoid overflow
1349 	 */
1350 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
1351 	return (y);
1352 }
1353 
1354 static __inline u_int64_t
1355 seg_y2x(u_int64_t y, u_int64_t ism)
1356 {
1357 	u_int64_t x;
1358 
1359 	if (y == 0)
1360 		x = 0;
1361 	else if (ism == HT_INFINITY)
1362 		x = HT_INFINITY;
1363 	else {
1364 		x = (y >> ISM_SHIFT) * ism
1365 		    + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
1366 	}
1367 	return (x);
1368 }
1369 
1370 static __inline u_int64_t
1371 m2sm(u_int64_t m)
1372 {
1373 	u_int64_t sm;
1374 
1375 	sm = (m << SM_SHIFT) / 8 / machclk_freq;
1376 	return (sm);
1377 }
1378 
1379 static __inline u_int64_t
1380 m2ism(u_int64_t m)
1381 {
1382 	u_int64_t ism;
1383 
1384 	if (m == 0)
1385 		ism = HT_INFINITY;
1386 	else
1387 		ism = ((u_int64_t)machclk_freq << ISM_SHIFT) * 8 / m;
1388 	return (ism);
1389 }
1390 
1391 static __inline u_int64_t
1392 d2dx(u_int d)
1393 {
1394 	u_int64_t dx;
1395 
1396 	dx = ((u_int64_t)d * machclk_freq) / 1000;
1397 	return (dx);
1398 }
1399 
1400 static u_int64_t
1401 sm2m(u_int64_t sm)
1402 {
1403 	u_int64_t m;
1404 
1405 	m = (sm * 8 * machclk_freq) >> SM_SHIFT;
1406 	return (m);
1407 }
1408 
1409 static u_int
1410 dx2d(u_int64_t dx)
1411 {
1412 	u_int64_t d;
1413 
1414 	d = dx * 1000 / machclk_freq;
1415 	return ((u_int)d);
1416 }
1417 
1418 static void
1419 sc2isc(struct service_curve *sc, struct internal_sc *isc)
1420 {
1421 	isc->sm1 = m2sm(sc->m1);
1422 	isc->ism1 = m2ism(sc->m1);
1423 	isc->dx = d2dx(sc->d);
1424 	isc->dy = seg_x2y(isc->dx, isc->sm1);
1425 	isc->sm2 = m2sm(sc->m2);
1426 	isc->ism2 = m2ism(sc->m2);
1427 }
1428 
1429 /*
1430  * initialize the runtime service curve with the given internal
1431  * service curve starting at (x, y).
1432  */
1433 static void
1434 rtsc_init(struct runtime_sc *rtsc, struct internal_sc * isc, u_int64_t x,
1435     u_int64_t y)
1436 {
1437 	rtsc->x =	x;
1438 	rtsc->y =	y;
1439 	rtsc->sm1 =	isc->sm1;
1440 	rtsc->ism1 =	isc->ism1;
1441 	rtsc->dx =	isc->dx;
1442 	rtsc->dy =	isc->dy;
1443 	rtsc->sm2 =	isc->sm2;
1444 	rtsc->ism2 =	isc->ism2;
1445 }
1446 
1447 /*
1448  * calculate the y-projection of the runtime service curve by the
1449  * given x-projection value
1450  */
1451 static u_int64_t
1452 rtsc_y2x(struct runtime_sc *rtsc, u_int64_t y)
1453 {
1454 	u_int64_t	x;
1455 
1456 	if (y < rtsc->y)
1457 		x = rtsc->x;
1458 	else if (y <= rtsc->y + rtsc->dy) {
1459 		/* x belongs to the 1st segment */
1460 		if (rtsc->dy == 0)
1461 			x = rtsc->x + rtsc->dx;
1462 		else
1463 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
1464 	} else {
1465 		/* x belongs to the 2nd segment */
1466 		x = rtsc->x + rtsc->dx
1467 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
1468 	}
1469 	return (x);
1470 }
1471 
1472 static u_int64_t
1473 rtsc_x2y(struct runtime_sc *rtsc, u_int64_t x)
1474 {
1475 	u_int64_t	y;
1476 
1477 	if (x <= rtsc->x)
1478 		y = rtsc->y;
1479 	else if (x <= rtsc->x + rtsc->dx)
1480 		/* y belongs to the 1st segment */
1481 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
1482 	else
1483 		/* y belongs to the 2nd segment */
1484 		y = rtsc->y + rtsc->dy
1485 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
1486 	return (y);
1487 }
1488 
1489 /*
1490  * update the runtime service curve by taking the minimum of the current
1491  * runtime service curve and the service curve starting at (x, y).
1492  */
1493 static void
1494 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u_int64_t x,
1495     u_int64_t y)
1496 {
1497 	u_int64_t	y1, y2, dx, dy;
1498 
1499 	if (isc->sm1 <= isc->sm2) {
1500 		/* service curve is convex */
1501 		y1 = rtsc_x2y(rtsc, x);
1502 		if (y1 < y)
1503 			/* the current rtsc is smaller */
1504 			return;
1505 		rtsc->x = x;
1506 		rtsc->y = y;
1507 		return;
1508 	}
1509 
1510 	/*
1511 	 * service curve is concave
1512 	 * compute the two y values of the current rtsc
1513 	 *	y1: at x
1514 	 *	y2: at (x + dx)
1515 	 */
1516 	y1 = rtsc_x2y(rtsc, x);
1517 	if (y1 <= y) {
1518 		/* rtsc is below isc, no change to rtsc */
1519 		return;
1520 	}
1521 
1522 	y2 = rtsc_x2y(rtsc, x + isc->dx);
1523 	if (y2 >= y + isc->dy) {
1524 		/* rtsc is above isc, replace rtsc by isc */
1525 		rtsc->x = x;
1526 		rtsc->y = y;
1527 		rtsc->dx = isc->dx;
1528 		rtsc->dy = isc->dy;
1529 		return;
1530 	}
1531 
1532 	/*
1533 	 * the two curves intersect
1534 	 * compute the offsets (dx, dy) using the reverse
1535 	 * function of seg_x2y()
1536 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
1537 	 */
1538 	dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2);
1539 	/*
1540 	 * check if (x, y1) belongs to the 1st segment of rtsc.
1541 	 * if so, add the offset.
1542 	 */
1543 	if (rtsc->x + rtsc->dx > x)
1544 		dx += rtsc->x + rtsc->dx - x;
1545 	dy = seg_x2y(dx, isc->sm1);
1546 
1547 	rtsc->x = x;
1548 	rtsc->y = y;
1549 	rtsc->dx = dx;
1550 	rtsc->dy = dy;
1551 	return;
1552 }
1553 
1554 static void
1555 get_class_stats_v0(struct hfsc_classstats_v0 *sp, struct hfsc_class *cl)
1556 {
1557 	sp->class_id = cl->cl_id;
1558 	sp->class_handle = cl->cl_handle;
1559 
1560 #define SATU32(x)	(u_int32_t)uqmin((x), UINT_MAX)
1561 
1562 	if (cl->cl_rsc != NULL) {
1563 		sp->rsc.m1 = SATU32(sm2m(cl->cl_rsc->sm1));
1564 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1565 		sp->rsc.m2 = SATU32(sm2m(cl->cl_rsc->sm2));
1566 	} else {
1567 		sp->rsc.m1 = 0;
1568 		sp->rsc.d = 0;
1569 		sp->rsc.m2 = 0;
1570 	}
1571 	if (cl->cl_fsc != NULL) {
1572 		sp->fsc.m1 = SATU32(sm2m(cl->cl_fsc->sm1));
1573 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1574 		sp->fsc.m2 = SATU32(sm2m(cl->cl_fsc->sm2));
1575 	} else {
1576 		sp->fsc.m1 = 0;
1577 		sp->fsc.d = 0;
1578 		sp->fsc.m2 = 0;
1579 	}
1580 	if (cl->cl_usc != NULL) {
1581 		sp->usc.m1 = SATU32(sm2m(cl->cl_usc->sm1));
1582 		sp->usc.d = dx2d(cl->cl_usc->dx);
1583 		sp->usc.m2 = SATU32(sm2m(cl->cl_usc->sm2));
1584 	} else {
1585 		sp->usc.m1 = 0;
1586 		sp->usc.d = 0;
1587 		sp->usc.m2 = 0;
1588 	}
1589 
1590 #undef SATU32
1591 
1592 	sp->total = cl->cl_total;
1593 	sp->cumul = cl->cl_cumul;
1594 
1595 	sp->d = cl->cl_d;
1596 	sp->e = cl->cl_e;
1597 	sp->vt = cl->cl_vt;
1598 	sp->f = cl->cl_f;
1599 
1600 	sp->initvt = cl->cl_initvt;
1601 	sp->vtperiod = cl->cl_vtperiod;
1602 	sp->parentperiod = cl->cl_parentperiod;
1603 	sp->nactive = cl->cl_nactive;
1604 	sp->vtoff = cl->cl_vtoff;
1605 	sp->cvtmax = cl->cl_cvtmax;
1606 	sp->myf = cl->cl_myf;
1607 	sp->cfmin = cl->cl_cfmin;
1608 	sp->cvtmin = cl->cl_cvtmin;
1609 	sp->myfadj = cl->cl_myfadj;
1610 	sp->vtadj = cl->cl_vtadj;
1611 
1612 	sp->cur_time = read_machclk();
1613 	sp->machclk_freq = machclk_freq;
1614 
1615 	sp->qlength = qlen(cl->cl_q);
1616 	sp->qlimit = qlimit(cl->cl_q);
1617 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1618 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1619 	sp->period = cl->cl_stats.period;
1620 
1621 	sp->qtype = qtype(cl->cl_q);
1622 #ifdef ALTQ_RED
1623 	if (q_is_red(cl->cl_q))
1624 		red_getstats(cl->cl_red, &sp->red[0]);
1625 #endif
1626 #ifdef ALTQ_RIO
1627 	if (q_is_rio(cl->cl_q))
1628 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1629 #endif
1630 #ifdef ALTQ_CODEL
1631 	if (q_is_codel(cl->cl_q))
1632 		codel_getstats(cl->cl_codel, &sp->codel);
1633 #endif
1634 }
1635 
1636 static void
1637 get_class_stats_v1(struct hfsc_classstats_v1 *sp, struct hfsc_class *cl)
1638 {
1639 	sp->class_id = cl->cl_id;
1640 	sp->class_handle = cl->cl_handle;
1641 
1642 	if (cl->cl_rsc != NULL) {
1643 		sp->rsc.m1 = sm2m(cl->cl_rsc->sm1);
1644 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1645 		sp->rsc.m2 = sm2m(cl->cl_rsc->sm2);
1646 	} else {
1647 		sp->rsc.m1 = 0;
1648 		sp->rsc.d = 0;
1649 		sp->rsc.m2 = 0;
1650 	}
1651 	if (cl->cl_fsc != NULL) {
1652 		sp->fsc.m1 = sm2m(cl->cl_fsc->sm1);
1653 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1654 		sp->fsc.m2 = sm2m(cl->cl_fsc->sm2);
1655 	} else {
1656 		sp->fsc.m1 = 0;
1657 		sp->fsc.d = 0;
1658 		sp->fsc.m2 = 0;
1659 	}
1660 	if (cl->cl_usc != NULL) {
1661 		sp->usc.m1 = sm2m(cl->cl_usc->sm1);
1662 		sp->usc.d = dx2d(cl->cl_usc->dx);
1663 		sp->usc.m2 = sm2m(cl->cl_usc->sm2);
1664 	} else {
1665 		sp->usc.m1 = 0;
1666 		sp->usc.d = 0;
1667 		sp->usc.m2 = 0;
1668 	}
1669 
1670 	sp->total = cl->cl_total;
1671 	sp->cumul = cl->cl_cumul;
1672 
1673 	sp->d = cl->cl_d;
1674 	sp->e = cl->cl_e;
1675 	sp->vt = cl->cl_vt;
1676 	sp->f = cl->cl_f;
1677 
1678 	sp->initvt = cl->cl_initvt;
1679 	sp->vtperiod = cl->cl_vtperiod;
1680 	sp->parentperiod = cl->cl_parentperiod;
1681 	sp->nactive = cl->cl_nactive;
1682 	sp->vtoff = cl->cl_vtoff;
1683 	sp->cvtmax = cl->cl_cvtmax;
1684 	sp->myf = cl->cl_myf;
1685 	sp->cfmin = cl->cl_cfmin;
1686 	sp->cvtmin = cl->cl_cvtmin;
1687 	sp->myfadj = cl->cl_myfadj;
1688 	sp->vtadj = cl->cl_vtadj;
1689 
1690 	sp->cur_time = read_machclk();
1691 	sp->machclk_freq = machclk_freq;
1692 
1693 	sp->qlength = qlen(cl->cl_q);
1694 	sp->qlimit = qlimit(cl->cl_q);
1695 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1696 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1697 	sp->period = cl->cl_stats.period;
1698 
1699 	sp->qtype = qtype(cl->cl_q);
1700 #ifdef ALTQ_RED
1701 	if (q_is_red(cl->cl_q))
1702 		red_getstats(cl->cl_red, &sp->red[0]);
1703 #endif
1704 #ifdef ALTQ_RIO
1705 	if (q_is_rio(cl->cl_q))
1706 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1707 #endif
1708 #ifdef ALTQ_CODEL
1709 	if (q_is_codel(cl->cl_q))
1710 		codel_getstats(cl->cl_codel, &sp->codel);
1711 #endif
1712 }
1713 
1714 /* convert a class handle to the corresponding class pointer */
1715 static struct hfsc_class *
1716 clh_to_clp(struct hfsc_if *hif, u_int32_t chandle)
1717 {
1718 	int i;
1719 	struct hfsc_class *cl;
1720 
1721 	if (chandle == 0)
1722 		return (NULL);
1723 	/*
1724 	 * first, try optimistically the slot matching the lower bits of
1725 	 * the handle.  if it fails, do the linear table search.
1726 	 */
1727 	i = chandle % HFSC_MAX_CLASSES;
1728 	if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle)
1729 		return (cl);
1730 	for (i = 0; i < HFSC_MAX_CLASSES; i++)
1731 		if ((cl = hif->hif_class_tbl[i]) != NULL &&
1732 		    cl->cl_handle == chandle)
1733 			return (cl);
1734 	return (NULL);
1735 }
1736 
1737 #endif /* ALTQ_HFSC */
1738