xref: /freebsd/sys/net/altq/altq_hfsc.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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 <netinet/in.h>
67 
68 #include <netpfil/pf/pf.h>
69 #include <netpfil/pf/pf_altq.h>
70 #include <netpfil/pf/pf_mtag.h>
71 #include <net/altq/altq.h>
72 #include <net/altq/altq_hfsc.h>
73 
74 /*
75  * function prototypes
76  */
77 static int			 hfsc_clear_interface(struct hfsc_if *);
78 static int			 hfsc_request(struct ifaltq *, int, void *);
79 static void			 hfsc_purge(struct hfsc_if *);
80 static struct hfsc_class	*hfsc_class_create(struct hfsc_if *,
81     struct service_curve *, struct service_curve *, struct service_curve *,
82     struct hfsc_class *, int, int, int);
83 static int			 hfsc_class_destroy(struct hfsc_class *);
84 static struct hfsc_class	*hfsc_nextclass(struct hfsc_class *);
85 static int			 hfsc_enqueue(struct ifaltq *, struct mbuf *,
86 				    struct altq_pktattr *);
87 static struct mbuf		*hfsc_dequeue(struct ifaltq *, int);
88 
89 static int		 hfsc_addq(struct hfsc_class *, struct mbuf *);
90 static struct mbuf	*hfsc_getq(struct hfsc_class *);
91 static struct mbuf	*hfsc_pollq(struct hfsc_class *);
92 static void		 hfsc_purgeq(struct hfsc_class *);
93 
94 static void		 update_cfmin(struct hfsc_class *);
95 static void		 set_active(struct hfsc_class *, int);
96 static void		 set_passive(struct hfsc_class *);
97 
98 static void		 init_ed(struct hfsc_class *, int);
99 static void		 update_ed(struct hfsc_class *, int);
100 static void		 update_d(struct hfsc_class *, int);
101 static void		 init_vf(struct hfsc_class *, int);
102 static void		 update_vf(struct hfsc_class *, int, u_int64_t);
103 static void		 ellist_insert(struct hfsc_class *);
104 static void		 ellist_remove(struct hfsc_class *);
105 static void		 ellist_update(struct hfsc_class *);
106 struct hfsc_class	*hfsc_get_mindl(struct hfsc_if *, u_int64_t);
107 static void		 actlist_insert(struct hfsc_class *);
108 static void		 actlist_remove(struct hfsc_class *);
109 static void		 actlist_update(struct hfsc_class *);
110 
111 static struct hfsc_class	*actlist_firstfit(struct hfsc_class *,
112 				    u_int64_t);
113 
114 static __inline u_int64_t	seg_x2y(u_int64_t, u_int64_t);
115 static __inline u_int64_t	seg_y2x(u_int64_t, u_int64_t);
116 static __inline u_int64_t	m2sm(u_int64_t);
117 static __inline u_int64_t	m2ism(u_int64_t);
118 static __inline u_int64_t	d2dx(u_int);
119 static u_int64_t		sm2m(u_int64_t);
120 static u_int			dx2d(u_int64_t);
121 
122 static void		sc2isc(struct service_curve *, struct internal_sc *);
123 static void		rtsc_init(struct runtime_sc *, struct internal_sc *,
124 			    u_int64_t, u_int64_t);
125 static u_int64_t	rtsc_y2x(struct runtime_sc *, u_int64_t);
126 static u_int64_t	rtsc_x2y(struct runtime_sc *, u_int64_t);
127 static void		rtsc_min(struct runtime_sc *, struct internal_sc *,
128 			    u_int64_t, u_int64_t);
129 
130 static void			 get_class_stats_v0(struct hfsc_classstats_v0 *,
131 				    struct hfsc_class *);
132 static void			 get_class_stats_v1(struct hfsc_classstats_v1 *,
133 				    struct hfsc_class *);
134 static struct hfsc_class	*clh_to_clp(struct hfsc_if *, u_int32_t);
135 
136 /*
137  * macros
138  */
139 #define	is_a_parent_class(cl)	((cl)->cl_children != NULL)
140 
141 #define	HT_INFINITY	0xffffffffffffffffULL	/* infinite time value */
142 
143 int
144 hfsc_pfattach(struct pf_altq *a)
145 {
146 	struct ifnet *ifp;
147 	int s, error;
148 
149 	if ((ifp = ifunit(a->ifname)) == NULL || a->altq_disc == NULL)
150 		return (EINVAL);
151 	s = splnet();
152 	error = altq_attach(&ifp->if_snd, ALTQT_HFSC, a->altq_disc,
153 	    hfsc_enqueue, hfsc_dequeue, hfsc_request);
154 	splx(s);
155 	return (error);
156 }
157 
158 int
159 hfsc_add_altq(struct ifnet *ifp, struct pf_altq *a)
160 {
161 	struct hfsc_if *hif;
162 
163 	if (ifp == NULL)
164 		return (EINVAL);
165 	if (!ALTQ_IS_READY(&ifp->if_snd))
166 		return (ENODEV);
167 
168 	hif = malloc(sizeof(struct hfsc_if), M_DEVBUF, M_NOWAIT | M_ZERO);
169 	if (hif == NULL)
170 		return (ENOMEM);
171 
172 	TAILQ_INIT(&hif->hif_eligible);
173 	hif->hif_ifq = &ifp->if_snd;
174 
175 	/* keep the state in pf_altq */
176 	a->altq_disc = hif;
177 
178 	return (0);
179 }
180 
181 int
182 hfsc_remove_altq(struct pf_altq *a)
183 {
184 	struct hfsc_if *hif;
185 
186 	if ((hif = a->altq_disc) == NULL)
187 		return (EINVAL);
188 	a->altq_disc = NULL;
189 
190 	(void)hfsc_clear_interface(hif);
191 	(void)hfsc_class_destroy(hif->hif_rootclass);
192 
193 	free(hif, M_DEVBUF);
194 
195 	return (0);
196 }
197 
198 int
199 hfsc_add_queue(struct pf_altq *a)
200 {
201 	struct hfsc_if *hif;
202 	struct hfsc_class *cl, *parent;
203 	struct hfsc_opts_v1 *opts;
204 	struct service_curve rtsc, lssc, ulsc;
205 
206 	if ((hif = a->altq_disc) == NULL)
207 		return (EINVAL);
208 
209 	opts = &a->pq_u.hfsc_opts;
210 
211 	if (a->parent_qid == HFSC_NULLCLASS_HANDLE &&
212 	    hif->hif_rootclass == NULL)
213 		parent = NULL;
214 	else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL)
215 		return (EINVAL);
216 
217 	if (a->qid == 0)
218 		return (EINVAL);
219 
220 	if (clh_to_clp(hif, a->qid) != NULL)
221 		return (EBUSY);
222 
223 	rtsc.m1 = opts->rtsc_m1;
224 	rtsc.d  = opts->rtsc_d;
225 	rtsc.m2 = opts->rtsc_m2;
226 	lssc.m1 = opts->lssc_m1;
227 	lssc.d  = opts->lssc_d;
228 	lssc.m2 = opts->lssc_m2;
229 	ulsc.m1 = opts->ulsc_m1;
230 	ulsc.d  = opts->ulsc_d;
231 	ulsc.m2 = opts->ulsc_m2;
232 
233 	cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc,
234 	    parent, a->qlimit, opts->flags, a->qid);
235 	if (cl == NULL)
236 		return (ENOMEM);
237 
238 	return (0);
239 }
240 
241 int
242 hfsc_remove_queue(struct pf_altq *a)
243 {
244 	struct hfsc_if *hif;
245 	struct hfsc_class *cl;
246 
247 	if ((hif = a->altq_disc) == NULL)
248 		return (EINVAL);
249 
250 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
251 		return (EINVAL);
252 
253 	return (hfsc_class_destroy(cl));
254 }
255 
256 int
257 hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes, int version)
258 {
259 	struct hfsc_if *hif;
260 	struct hfsc_class *cl;
261 	union {
262 		struct hfsc_classstats_v0 v0;
263 		struct hfsc_classstats_v1 v1;
264 	} stats;
265 	size_t stats_size;
266 	int error = 0;
267 
268 	if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL)
269 		return (EBADF);
270 
271 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
272 		return (EINVAL);
273 
274 	if (version > HFSC_STATS_VERSION)
275 		return (EINVAL);
276 
277 	memset(&stats, 0, sizeof(stats));
278 	switch (version) {
279 	case 0:
280 		get_class_stats_v0(&stats.v0, cl);
281 		stats_size = sizeof(struct hfsc_classstats_v0);
282 		break;
283 	case 1:
284 		get_class_stats_v1(&stats.v1, cl);
285 		stats_size = sizeof(struct hfsc_classstats_v1);
286 		break;
287 	}
288 
289 	if (*nbytes < stats_size)
290 		return (EINVAL);
291 
292 	if ((error = copyout((caddr_t)&stats, ubuf, stats_size)) != 0)
293 		return (error);
294 	*nbytes = stats_size;
295 	return (0);
296 }
297 
298 /*
299  * bring the interface back to the initial state by discarding
300  * all the filters and classes except the root class.
301  */
302 static int
303 hfsc_clear_interface(struct hfsc_if *hif)
304 {
305 	struct hfsc_class	*cl;
306 
307 	/* clear out the classes */
308 	while (hif->hif_rootclass != NULL &&
309 	    (cl = hif->hif_rootclass->cl_children) != NULL) {
310 		/*
311 		 * remove the first leaf class found in the hierarchy
312 		 * then start over
313 		 */
314 		for (; cl != NULL; cl = hfsc_nextclass(cl)) {
315 			if (!is_a_parent_class(cl)) {
316 				(void)hfsc_class_destroy(cl);
317 				break;
318 			}
319 		}
320 	}
321 
322 	return (0);
323 }
324 
325 static int
326 hfsc_request(struct ifaltq *ifq, int req, void *arg)
327 {
328 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
329 
330 	IFQ_LOCK_ASSERT(ifq);
331 
332 	switch (req) {
333 	case ALTRQ_PURGE:
334 		hfsc_purge(hif);
335 		break;
336 	}
337 	return (0);
338 }
339 
340 /* discard all the queued packets on the interface */
341 static void
342 hfsc_purge(struct hfsc_if *hif)
343 {
344 	struct hfsc_class *cl;
345 
346 	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
347 		if (!qempty(cl->cl_q))
348 			hfsc_purgeq(cl);
349 	if (ALTQ_IS_ENABLED(hif->hif_ifq))
350 		hif->hif_ifq->ifq_len = 0;
351 }
352 
353 struct hfsc_class *
354 hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc,
355     struct service_curve *fsc, struct service_curve *usc,
356     struct hfsc_class *parent, int qlimit, int flags, int qid)
357 {
358 	struct hfsc_class *cl, *p;
359 	int i, s;
360 
361 	if (hif->hif_classes >= HFSC_MAX_CLASSES)
362 		return (NULL);
363 
364 #ifndef ALTQ_RED
365 	if (flags & HFCF_RED) {
366 #ifdef ALTQ_DEBUG
367 		printf("hfsc_class_create: RED not configured for HFSC!\n");
368 #endif
369 		return (NULL);
370 	}
371 #endif
372 #ifndef ALTQ_CODEL
373 	if (flags & HFCF_CODEL) {
374 #ifdef ALTQ_DEBUG
375 		printf("hfsc_class_create: CODEL not configured for HFSC!\n");
376 #endif
377 		return (NULL);
378 	}
379 #endif
380 
381 	cl = malloc(sizeof(struct hfsc_class), M_DEVBUF, M_NOWAIT | M_ZERO);
382 	if (cl == NULL)
383 		return (NULL);
384 
385 	cl->cl_q = malloc(sizeof(class_queue_t), M_DEVBUF, M_NOWAIT | M_ZERO);
386 	if (cl->cl_q == NULL)
387 		goto err_ret;
388 
389 	TAILQ_INIT(&cl->cl_actc);
390 
391 	if (qlimit == 0)
392 		qlimit = 50;  /* use default */
393 	qlimit(cl->cl_q) = qlimit;
394 	qtype(cl->cl_q) = Q_DROPTAIL;
395 	qlen(cl->cl_q) = 0;
396 	qsize(cl->cl_q) = 0;
397 	cl->cl_flags = flags;
398 #ifdef ALTQ_RED
399 	if (flags & (HFCF_RED|HFCF_RIO)) {
400 		int red_flags, red_pkttime;
401 		u_int m2;
402 
403 		m2 = 0;
404 		if (rsc != NULL && rsc->m2 > m2)
405 			m2 = rsc->m2;
406 		if (fsc != NULL && fsc->m2 > m2)
407 			m2 = fsc->m2;
408 		if (usc != NULL && usc->m2 > m2)
409 			m2 = usc->m2;
410 
411 		red_flags = 0;
412 		if (flags & HFCF_ECN)
413 			red_flags |= REDF_ECN;
414 #ifdef ALTQ_RIO
415 		if (flags & HFCF_CLEARDSCP)
416 			red_flags |= RIOF_CLEARDSCP;
417 #endif
418 		if (m2 < 8)
419 			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
420 		else
421 			red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu
422 				* 1000 * 1000 * 1000 / (m2 / 8);
423 		if (flags & HFCF_RED) {
424 			cl->cl_red = red_alloc(0, 0,
425 			    qlimit(cl->cl_q) * 10/100,
426 			    qlimit(cl->cl_q) * 30/100,
427 			    red_flags, red_pkttime);
428 			if (cl->cl_red != NULL)
429 				qtype(cl->cl_q) = Q_RED;
430 		}
431 #ifdef ALTQ_RIO
432 		else {
433 			cl->cl_red = (red_t *)rio_alloc(0, NULL,
434 			    red_flags, red_pkttime);
435 			if (cl->cl_red != NULL)
436 				qtype(cl->cl_q) = Q_RIO;
437 		}
438 #endif
439 	}
440 #endif /* ALTQ_RED */
441 #ifdef ALTQ_CODEL
442 	if (flags & HFCF_CODEL) {
443 		cl->cl_codel = codel_alloc(5, 100, 0);
444 		if (cl->cl_codel != NULL)
445 			qtype(cl->cl_q) = Q_CODEL;
446 	}
447 #endif
448 
449 	if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
450 		cl->cl_rsc = malloc(sizeof(struct internal_sc),
451 		    M_DEVBUF, M_NOWAIT);
452 		if (cl->cl_rsc == NULL)
453 			goto err_ret;
454 		sc2isc(rsc, cl->cl_rsc);
455 		rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0);
456 		rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0);
457 	}
458 	if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) {
459 		cl->cl_fsc = malloc(sizeof(struct internal_sc),
460 		    M_DEVBUF, M_NOWAIT);
461 		if (cl->cl_fsc == NULL)
462 			goto err_ret;
463 		sc2isc(fsc, cl->cl_fsc);
464 		rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0);
465 	}
466 	if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) {
467 		cl->cl_usc = malloc(sizeof(struct internal_sc),
468 		    M_DEVBUF, M_NOWAIT);
469 		if (cl->cl_usc == NULL)
470 			goto err_ret;
471 		sc2isc(usc, cl->cl_usc);
472 		rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0);
473 	}
474 
475 	cl->cl_id = hif->hif_classid++;
476 	cl->cl_handle = qid;
477 	cl->cl_hif = hif;
478 	cl->cl_parent = parent;
479 
480 	s = splnet();
481 	IFQ_LOCK(hif->hif_ifq);
482 	hif->hif_classes++;
483 
484 	/*
485 	 * find a free slot in the class table.  if the slot matching
486 	 * the lower bits of qid is free, use this slot.  otherwise,
487 	 * use the first free slot.
488 	 */
489 	i = qid % HFSC_MAX_CLASSES;
490 	if (hif->hif_class_tbl[i] == NULL)
491 		hif->hif_class_tbl[i] = cl;
492 	else {
493 		for (i = 0; i < HFSC_MAX_CLASSES; i++)
494 			if (hif->hif_class_tbl[i] == NULL) {
495 				hif->hif_class_tbl[i] = cl;
496 				break;
497 			}
498 		if (i == HFSC_MAX_CLASSES) {
499 			IFQ_UNLOCK(hif->hif_ifq);
500 			splx(s);
501 			goto err_ret;
502 		}
503 	}
504 	cl->cl_slot = i;
505 
506 	if (flags & HFCF_DEFAULTCLASS)
507 		hif->hif_defaultclass = cl;
508 
509 	if (parent == NULL) {
510 		/* this is root class */
511 		hif->hif_rootclass = cl;
512 	} else {
513 		/* add this class to the children list of the parent */
514 		if ((p = parent->cl_children) == NULL)
515 			parent->cl_children = cl;
516 		else {
517 			/* Put new class at beginning of list */
518 			cl->cl_siblings = parent->cl_children;
519 			parent->cl_children = cl;
520 		}
521 	}
522 	IFQ_UNLOCK(hif->hif_ifq);
523 	splx(s);
524 
525 	return (cl);
526 
527  err_ret:
528 	if (cl->cl_red != NULL) {
529 #ifdef ALTQ_RIO
530 		if (q_is_rio(cl->cl_q))
531 			rio_destroy((rio_t *)cl->cl_red);
532 #endif
533 #ifdef ALTQ_RED
534 		if (q_is_red(cl->cl_q))
535 			red_destroy(cl->cl_red);
536 #endif
537 #ifdef ALTQ_CODEL
538 		if (q_is_codel(cl->cl_q))
539 			codel_destroy(cl->cl_codel);
540 #endif
541 	}
542 	if (cl->cl_fsc != NULL)
543 		free(cl->cl_fsc, M_DEVBUF);
544 	if (cl->cl_rsc != NULL)
545 		free(cl->cl_rsc, M_DEVBUF);
546 	if (cl->cl_usc != NULL)
547 		free(cl->cl_usc, M_DEVBUF);
548 	if (cl->cl_q != NULL)
549 		free(cl->cl_q, M_DEVBUF);
550 	free(cl, M_DEVBUF);
551 	return (NULL);
552 }
553 
554 static int
555 hfsc_class_destroy(struct hfsc_class *cl)
556 {
557 	int s;
558 
559 	if (cl == NULL)
560 		return (0);
561 
562 	if (is_a_parent_class(cl))
563 		return (EBUSY);
564 
565 	s = splnet();
566 	IFQ_LOCK(cl->cl_hif->hif_ifq);
567 
568 	if (!qempty(cl->cl_q))
569 		hfsc_purgeq(cl);
570 
571 	if (cl->cl_parent == NULL) {
572 		/* this is root class */
573 	} else {
574 		struct hfsc_class *p = cl->cl_parent->cl_children;
575 
576 		if (p == cl)
577 			cl->cl_parent->cl_children = cl->cl_siblings;
578 		else do {
579 			if (p->cl_siblings == cl) {
580 				p->cl_siblings = cl->cl_siblings;
581 				break;
582 			}
583 		} while ((p = p->cl_siblings) != NULL);
584 		ASSERT(p != NULL);
585 	}
586 
587 	cl->cl_hif->hif_class_tbl[cl->cl_slot] = NULL;
588 	cl->cl_hif->hif_classes--;
589 	IFQ_UNLOCK(cl->cl_hif->hif_ifq);
590 	splx(s);
591 
592 	if (cl->cl_red != NULL) {
593 #ifdef ALTQ_RIO
594 		if (q_is_rio(cl->cl_q))
595 			rio_destroy((rio_t *)cl->cl_red);
596 #endif
597 #ifdef ALTQ_RED
598 		if (q_is_red(cl->cl_q))
599 			red_destroy(cl->cl_red);
600 #endif
601 #ifdef ALTQ_CODEL
602 		if (q_is_codel(cl->cl_q))
603 			codel_destroy(cl->cl_codel);
604 #endif
605 	}
606 
607 	IFQ_LOCK(cl->cl_hif->hif_ifq);
608 	if (cl == cl->cl_hif->hif_rootclass)
609 		cl->cl_hif->hif_rootclass = NULL;
610 	if (cl == cl->cl_hif->hif_defaultclass)
611 		cl->cl_hif->hif_defaultclass = NULL;
612 	IFQ_UNLOCK(cl->cl_hif->hif_ifq);
613 
614 	if (cl->cl_usc != NULL)
615 		free(cl->cl_usc, M_DEVBUF);
616 	if (cl->cl_fsc != NULL)
617 		free(cl->cl_fsc, M_DEVBUF);
618 	if (cl->cl_rsc != NULL)
619 		free(cl->cl_rsc, M_DEVBUF);
620 	free(cl->cl_q, M_DEVBUF);
621 	free(cl, M_DEVBUF);
622 
623 	return (0);
624 }
625 
626 /*
627  * hfsc_nextclass returns the next class in the tree.
628  *   usage:
629  *	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
630  *		do_something;
631  */
632 static struct hfsc_class *
633 hfsc_nextclass(struct hfsc_class *cl)
634 {
635 	if (cl->cl_children != NULL)
636 		cl = cl->cl_children;
637 	else if (cl->cl_siblings != NULL)
638 		cl = cl->cl_siblings;
639 	else {
640 		while ((cl = cl->cl_parent) != NULL)
641 			if (cl->cl_siblings) {
642 				cl = cl->cl_siblings;
643 				break;
644 			}
645 	}
646 
647 	return (cl);
648 }
649 
650 /*
651  * hfsc_enqueue is an enqueue function to be registered to
652  * (*altq_enqueue) in struct ifaltq.
653  */
654 static int
655 hfsc_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr)
656 {
657 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
658 	struct hfsc_class *cl;
659 	struct pf_mtag *t;
660 	int len;
661 
662 	IFQ_LOCK_ASSERT(ifq);
663 
664 	/* grab class set by classifier */
665 	if ((m->m_flags & M_PKTHDR) == 0) {
666 		/* should not happen */
667 		printf("altq: packet for %s does not have pkthdr\n",
668 		    ifq->altq_ifp->if_xname);
669 		m_freem(m);
670 		return (ENOBUFS);
671 	}
672 	cl = NULL;
673 	if ((t = pf_find_mtag(m)) != NULL)
674 		cl = clh_to_clp(hif, t->qid);
675 	if (cl == NULL || is_a_parent_class(cl)) {
676 		cl = hif->hif_defaultclass;
677 		if (cl == NULL) {
678 			m_freem(m);
679 			return (ENOBUFS);
680 		}
681 	}
682 	cl->cl_pktattr = NULL;
683 	len = m_pktlen(m);
684 	if (hfsc_addq(cl, m) != 0) {
685 		/* drop occurred.  mbuf was freed in hfsc_addq. */
686 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len);
687 		return (ENOBUFS);
688 	}
689 	IFQ_INC_LEN(ifq);
690 	cl->cl_hif->hif_packets++;
691 
692 	/* successfully queued. */
693 	if (qlen(cl->cl_q) == 1)
694 		set_active(cl, m_pktlen(m));
695 
696 	return (0);
697 }
698 
699 /*
700  * hfsc_dequeue is a dequeue function to be registered to
701  * (*altq_dequeue) in struct ifaltq.
702  *
703  * note: ALTDQ_POLL returns the next packet without removing the packet
704  *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
705  *	ALTDQ_REMOVE must return the same packet if called immediately
706  *	after ALTDQ_POLL.
707  */
708 static struct mbuf *
709 hfsc_dequeue(struct ifaltq *ifq, int op)
710 {
711 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
712 	struct hfsc_class *cl;
713 	struct mbuf *m;
714 	int len, next_len;
715 	int realtime = 0;
716 	u_int64_t cur_time;
717 
718 	IFQ_LOCK_ASSERT(ifq);
719 
720 	if (hif->hif_packets == 0)
721 		/* no packet in the tree */
722 		return (NULL);
723 
724 	cur_time = read_machclk();
725 
726 	if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) {
727 		cl = hif->hif_pollcache;
728 		hif->hif_pollcache = NULL;
729 		/* check if the class was scheduled by real-time criteria */
730 		if (cl->cl_rsc != NULL)
731 			realtime = (cl->cl_e <= cur_time);
732 	} else {
733 		/*
734 		 * if there are eligible classes, use real-time criteria.
735 		 * find the class with the minimum deadline among
736 		 * the eligible classes.
737 		 */
738 		if ((cl = hfsc_get_mindl(hif, cur_time))
739 		    != NULL) {
740 			realtime = 1;
741 		} else {
742 #ifdef ALTQ_DEBUG
743 			int fits = 0;
744 #endif
745 			/*
746 			 * use link-sharing criteria
747 			 * get the class with the minimum vt in the hierarchy
748 			 */
749 			cl = hif->hif_rootclass;
750 			while (is_a_parent_class(cl)) {
751 				cl = actlist_firstfit(cl, cur_time);
752 				if (cl == NULL) {
753 #ifdef ALTQ_DEBUG
754 					if (fits > 0)
755 						printf("%d fit but none found\n",fits);
756 #endif
757 					return (NULL);
758 				}
759 				/*
760 				 * update parent's cl_cvtmin.
761 				 * don't update if the new vt is smaller.
762 				 */
763 				if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
764 					cl->cl_parent->cl_cvtmin = cl->cl_vt;
765 #ifdef ALTQ_DEBUG
766 				fits++;
767 #endif
768 			}
769 		}
770 
771 		if (op == ALTDQ_POLL) {
772 			hif->hif_pollcache = cl;
773 			m = hfsc_pollq(cl);
774 			return (m);
775 		}
776 	}
777 
778 	m = hfsc_getq(cl);
779 	if (m == NULL)
780 		panic("hfsc_dequeue:");
781 	len = m_pktlen(m);
782 	cl->cl_hif->hif_packets--;
783 	IFQ_DEC_LEN(ifq);
784 	PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len);
785 
786 	update_vf(cl, len, cur_time);
787 	if (realtime)
788 		cl->cl_cumul += len;
789 
790 	if (!qempty(cl->cl_q)) {
791 		if (cl->cl_rsc != NULL) {
792 			/* update ed */
793 			next_len = m_pktlen(qhead(cl->cl_q));
794 
795 			if (realtime)
796 				update_ed(cl, next_len);
797 			else
798 				update_d(cl, next_len);
799 		}
800 	} else {
801 		/* the class becomes passive */
802 		set_passive(cl);
803 	}
804 
805 	return (m);
806 }
807 
808 static int
809 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
810 {
811 
812 #ifdef ALTQ_RIO
813 	if (q_is_rio(cl->cl_q))
814 		return rio_addq((rio_t *)cl->cl_red, cl->cl_q,
815 				m, cl->cl_pktattr);
816 #endif
817 #ifdef ALTQ_RED
818 	if (q_is_red(cl->cl_q))
819 		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
820 #endif
821 #ifdef ALTQ_CODEL
822 	if (q_is_codel(cl->cl_q))
823 		return codel_addq(cl->cl_codel, cl->cl_q, m);
824 #endif
825 	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
826 		m_freem(m);
827 		return (-1);
828 	}
829 
830 	if (cl->cl_flags & HFCF_CLEARDSCP)
831 		write_dsfield(m, cl->cl_pktattr, 0);
832 
833 	_addq(cl->cl_q, m);
834 
835 	return (0);
836 }
837 
838 static struct mbuf *
839 hfsc_getq(struct hfsc_class *cl)
840 {
841 #ifdef ALTQ_RIO
842 	if (q_is_rio(cl->cl_q))
843 		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
844 #endif
845 #ifdef ALTQ_RED
846 	if (q_is_red(cl->cl_q))
847 		return red_getq(cl->cl_red, cl->cl_q);
848 #endif
849 #ifdef ALTQ_CODEL
850 	if (q_is_codel(cl->cl_q))
851 		return codel_getq(cl->cl_codel, cl->cl_q);
852 #endif
853 	return _getq(cl->cl_q);
854 }
855 
856 static struct mbuf *
857 hfsc_pollq(struct hfsc_class *cl)
858 {
859 	return qhead(cl->cl_q);
860 }
861 
862 static void
863 hfsc_purgeq(struct hfsc_class *cl)
864 {
865 	struct mbuf *m;
866 
867 	if (qempty(cl->cl_q))
868 		return;
869 
870 	while ((m = _getq(cl->cl_q)) != NULL) {
871 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m));
872 		m_freem(m);
873 		cl->cl_hif->hif_packets--;
874 		IFQ_DEC_LEN(cl->cl_hif->hif_ifq);
875 	}
876 	ASSERT(qlen(cl->cl_q) == 0);
877 
878 	update_vf(cl, 0, 0);	/* remove cl from the actlist */
879 	set_passive(cl);
880 }
881 
882 static void
883 set_active(struct hfsc_class *cl, int len)
884 {
885 	if (cl->cl_rsc != NULL)
886 		init_ed(cl, len);
887 	if (cl->cl_fsc != NULL)
888 		init_vf(cl, len);
889 
890 	cl->cl_stats.period++;
891 }
892 
893 static void
894 set_passive(struct hfsc_class *cl)
895 {
896 	if (cl->cl_rsc != NULL)
897 		ellist_remove(cl);
898 
899 	/*
900 	 * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
901 	 * needs to be called explicitly to remove a class from actlist
902 	 */
903 }
904 
905 static void
906 init_ed(struct hfsc_class *cl, int next_len)
907 {
908 	u_int64_t cur_time;
909 
910 	cur_time = read_machclk();
911 
912 	/* update the deadline curve */
913 	rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul);
914 
915 	/*
916 	 * update the eligible curve.
917 	 * for concave, it is equal to the deadline curve.
918 	 * for convex, it is a linear curve with slope m2.
919 	 */
920 	cl->cl_eligible = cl->cl_deadline;
921 	if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) {
922 		cl->cl_eligible.dx = 0;
923 		cl->cl_eligible.dy = 0;
924 	}
925 
926 	/* compute e and d */
927 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
928 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
929 
930 	ellist_insert(cl);
931 }
932 
933 static void
934 update_ed(struct hfsc_class *cl, int next_len)
935 {
936 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
937 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
938 
939 	ellist_update(cl);
940 }
941 
942 static void
943 update_d(struct hfsc_class *cl, int next_len)
944 {
945 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
946 }
947 
948 static void
949 init_vf(struct hfsc_class *cl, int len)
950 {
951 	struct hfsc_class *max_cl, *p;
952 	u_int64_t vt, f, cur_time;
953 	int go_active;
954 
955 	cur_time = 0;
956 	go_active = 1;
957 	for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) {
958 		if (go_active && cl->cl_nactive++ == 0)
959 			go_active = 1;
960 		else
961 			go_active = 0;
962 
963 		if (go_active) {
964 			max_cl = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead);
965 			if (max_cl != NULL) {
966 				/*
967 				 * set vt to the average of the min and max
968 				 * classes.  if the parent's period didn't
969 				 * change, don't decrease vt of the class.
970 				 */
971 				vt = max_cl->cl_vt;
972 				if (cl->cl_parent->cl_cvtmin != 0)
973 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
974 
975 				if (cl->cl_parent->cl_vtperiod !=
976 				    cl->cl_parentperiod || vt > cl->cl_vt)
977 					cl->cl_vt = vt;
978 			} else {
979 				/*
980 				 * first child for a new parent backlog period.
981 				 * add parent's cvtmax to vtoff of children
982 				 * to make a new vt (vtoff + vt) larger than
983 				 * the vt in the last period for all children.
984 				 */
985 				vt = cl->cl_parent->cl_cvtmax;
986 				for (p = cl->cl_parent->cl_children; p != NULL;
987 				     p = p->cl_siblings)
988 					p->cl_vtoff += vt;
989 				cl->cl_vt = 0;
990 				cl->cl_parent->cl_cvtmax = 0;
991 				cl->cl_parent->cl_cvtmin = 0;
992 			}
993 			cl->cl_initvt = cl->cl_vt;
994 
995 			/* update the virtual curve */
996 			vt = cl->cl_vt + cl->cl_vtoff;
997 			rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total);
998 			if (cl->cl_virtual.x == vt) {
999 				cl->cl_virtual.x -= cl->cl_vtoff;
1000 				cl->cl_vtoff = 0;
1001 			}
1002 			cl->cl_vtadj = 0;
1003 
1004 			cl->cl_vtperiod++;  /* increment vt period */
1005 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
1006 			if (cl->cl_parent->cl_nactive == 0)
1007 				cl->cl_parentperiod++;
1008 			cl->cl_f = 0;
1009 
1010 			actlist_insert(cl);
1011 
1012 			if (cl->cl_usc != NULL) {
1013 				/* class has upper limit curve */
1014 				if (cur_time == 0)
1015 					cur_time = read_machclk();
1016 
1017 				/* update the ulimit curve */
1018 				rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time,
1019 				    cl->cl_total);
1020 				/* compute myf */
1021 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
1022 				    cl->cl_total);
1023 				cl->cl_myfadj = 0;
1024 			}
1025 		}
1026 
1027 		if (cl->cl_myf > cl->cl_cfmin)
1028 			f = cl->cl_myf;
1029 		else
1030 			f = cl->cl_cfmin;
1031 		if (f != cl->cl_f) {
1032 			cl->cl_f = f;
1033 			update_cfmin(cl->cl_parent);
1034 		}
1035 	}
1036 }
1037 
1038 static void
1039 update_vf(struct hfsc_class *cl, int len, u_int64_t cur_time)
1040 {
1041 	u_int64_t f, myf_bound, delta;
1042 	int go_passive;
1043 
1044 	go_passive = qempty(cl->cl_q);
1045 
1046 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
1047 		cl->cl_total += len;
1048 
1049 		if (cl->cl_fsc == NULL || cl->cl_nactive == 0)
1050 			continue;
1051 
1052 		if (go_passive && --cl->cl_nactive == 0)
1053 			go_passive = 1;
1054 		else
1055 			go_passive = 0;
1056 
1057 		if (go_passive) {
1058 			/* no more active child, going passive */
1059 
1060 			/* update cvtmax of the parent class */
1061 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
1062 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
1063 
1064 			/* remove this class from the vt list */
1065 			actlist_remove(cl);
1066 
1067 			update_cfmin(cl->cl_parent);
1068 
1069 			continue;
1070 		}
1071 
1072 		/*
1073 		 * update vt and f
1074 		 */
1075 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
1076 		    - cl->cl_vtoff + cl->cl_vtadj;
1077 
1078 		/*
1079 		 * if vt of the class is smaller than cvtmin,
1080 		 * the class was skipped in the past due to non-fit.
1081 		 * if so, we need to adjust vtadj.
1082 		 */
1083 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
1084 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
1085 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
1086 		}
1087 
1088 		/* update the vt list */
1089 		actlist_update(cl);
1090 
1091 		if (cl->cl_usc != NULL) {
1092 			cl->cl_myf = cl->cl_myfadj
1093 			    + rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
1094 
1095 			/*
1096 			 * if myf lags behind by more than one clock tick
1097 			 * from the current time, adjust myfadj to prevent
1098 			 * a rate-limited class from going greedy.
1099 			 * in a steady state under rate-limiting, myf
1100 			 * fluctuates within one clock tick.
1101 			 */
1102 			myf_bound = cur_time - machclk_per_tick;
1103 			if (cl->cl_myf < myf_bound) {
1104 				delta = cur_time - cl->cl_myf;
1105 				cl->cl_myfadj += delta;
1106 				cl->cl_myf += delta;
1107 			}
1108 		}
1109 
1110 		/* cl_f is max(cl_myf, cl_cfmin) */
1111 		if (cl->cl_myf > cl->cl_cfmin)
1112 			f = cl->cl_myf;
1113 		else
1114 			f = cl->cl_cfmin;
1115 		if (f != cl->cl_f) {
1116 			cl->cl_f = f;
1117 			update_cfmin(cl->cl_parent);
1118 		}
1119 	}
1120 }
1121 
1122 static void
1123 update_cfmin(struct hfsc_class *cl)
1124 {
1125 	struct hfsc_class *p;
1126 	u_int64_t cfmin;
1127 
1128 	if (TAILQ_EMPTY(&cl->cl_actc)) {
1129 		cl->cl_cfmin = 0;
1130 		return;
1131 	}
1132 	cfmin = HT_INFINITY;
1133 	TAILQ_FOREACH(p, &cl->cl_actc, cl_actlist) {
1134 		if (p->cl_f == 0) {
1135 			cl->cl_cfmin = 0;
1136 			return;
1137 		}
1138 		if (p->cl_f < cfmin)
1139 			cfmin = p->cl_f;
1140 	}
1141 	cl->cl_cfmin = cfmin;
1142 }
1143 
1144 /*
1145  * TAILQ based ellist and actlist implementation
1146  * (ion wanted to make a calendar queue based implementation)
1147  */
1148 /*
1149  * eligible list holds backlogged classes being sorted by their eligible times.
1150  * there is one eligible list per interface.
1151  */
1152 
1153 static void
1154 ellist_insert(struct hfsc_class *cl)
1155 {
1156 	struct hfsc_if	*hif = cl->cl_hif;
1157 	struct hfsc_class *p;
1158 
1159 	/* check the last entry first */
1160 	if ((p = TAILQ_LAST(&hif->hif_eligible, elighead)) == NULL ||
1161 	    p->cl_e <= cl->cl_e) {
1162 		TAILQ_INSERT_TAIL(&hif->hif_eligible, cl, cl_ellist);
1163 		return;
1164 	}
1165 
1166 	TAILQ_FOREACH(p, &hif->hif_eligible, cl_ellist) {
1167 		if (cl->cl_e < p->cl_e) {
1168 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1169 			return;
1170 		}
1171 	}
1172 	ASSERT(0); /* should not reach here */
1173 }
1174 
1175 static void
1176 ellist_remove(struct hfsc_class *cl)
1177 {
1178 	struct hfsc_if	*hif = cl->cl_hif;
1179 
1180 	TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist);
1181 }
1182 
1183 static void
1184 ellist_update(struct hfsc_class *cl)
1185 {
1186 	struct hfsc_if	*hif = cl->cl_hif;
1187 	struct hfsc_class *p, *last;
1188 
1189 	/*
1190 	 * the eligible time of a class increases monotonically.
1191 	 * if the next entry has a larger eligible time, nothing to do.
1192 	 */
1193 	p = TAILQ_NEXT(cl, cl_ellist);
1194 	if (p == NULL || cl->cl_e <= p->cl_e)
1195 		return;
1196 
1197 	/* check the last entry */
1198 	last = TAILQ_LAST(&hif->hif_eligible, elighead);
1199 	ASSERT(last != NULL);
1200 	if (last->cl_e <= cl->cl_e) {
1201 		TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist);
1202 		TAILQ_INSERT_TAIL(&hif->hif_eligible, cl, cl_ellist);
1203 		return;
1204 	}
1205 
1206 	/*
1207 	 * the new position must be between the next entry
1208 	 * and the last entry
1209 	 */
1210 	while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) {
1211 		if (cl->cl_e < p->cl_e) {
1212 			TAILQ_REMOVE(&hif->hif_eligible, cl, cl_ellist);
1213 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1214 			return;
1215 		}
1216 	}
1217 	ASSERT(0); /* should not reach here */
1218 }
1219 
1220 /* find the class with the minimum deadline among the eligible classes */
1221 struct hfsc_class *
1222 hfsc_get_mindl(struct hfsc_if *hif, u_int64_t cur_time)
1223 {
1224 	struct hfsc_class *p, *cl = NULL;
1225 
1226 	TAILQ_FOREACH(p, &hif->hif_eligible, cl_ellist) {
1227 		if (p->cl_e > cur_time)
1228 			break;
1229 		if (cl == NULL || p->cl_d < cl->cl_d)
1230 			cl = p;
1231 	}
1232 	return (cl);
1233 }
1234 
1235 /*
1236  * active children list holds backlogged child classes being sorted
1237  * by their virtual time.
1238  * each intermediate class has one active children list.
1239  */
1240 
1241 static void
1242 actlist_insert(struct hfsc_class *cl)
1243 {
1244 	struct hfsc_class *p;
1245 
1246 	/* check the last entry first */
1247 	if ((p = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead)) == NULL
1248 	    || p->cl_vt <= cl->cl_vt) {
1249 		TAILQ_INSERT_TAIL(&cl->cl_parent->cl_actc, cl, cl_actlist);
1250 		return;
1251 	}
1252 
1253 	TAILQ_FOREACH(p, &cl->cl_parent->cl_actc, cl_actlist) {
1254 		if (cl->cl_vt < p->cl_vt) {
1255 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1256 			return;
1257 		}
1258 	}
1259 	ASSERT(0); /* should not reach here */
1260 }
1261 
1262 static void
1263 actlist_remove(struct hfsc_class *cl)
1264 {
1265 	TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist);
1266 }
1267 
1268 static void
1269 actlist_update(struct hfsc_class *cl)
1270 {
1271 	struct hfsc_class *p, *last;
1272 
1273 	/*
1274 	 * the virtual time of a class increases monotonically during its
1275 	 * backlogged period.
1276 	 * if the next entry has a larger virtual time, nothing to do.
1277 	 */
1278 	p = TAILQ_NEXT(cl, cl_actlist);
1279 	if (p == NULL || cl->cl_vt < p->cl_vt)
1280 		return;
1281 
1282 	/* check the last entry */
1283 	last = TAILQ_LAST(&cl->cl_parent->cl_actc, acthead);
1284 	ASSERT(last != NULL);
1285 	if (last->cl_vt <= cl->cl_vt) {
1286 		TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist);
1287 		TAILQ_INSERT_TAIL(&cl->cl_parent->cl_actc, cl, cl_actlist);
1288 		return;
1289 	}
1290 
1291 	/*
1292 	 * the new position must be between the next entry
1293 	 * and the last entry
1294 	 */
1295 	while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) {
1296 		if (cl->cl_vt < p->cl_vt) {
1297 			TAILQ_REMOVE(&cl->cl_parent->cl_actc, cl, cl_actlist);
1298 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1299 			return;
1300 		}
1301 	}
1302 	ASSERT(0); /* should not reach here */
1303 }
1304 
1305 static struct hfsc_class *
1306 actlist_firstfit(struct hfsc_class *cl, u_int64_t cur_time)
1307 {
1308 	struct hfsc_class *p;
1309 
1310 	TAILQ_FOREACH(p, &cl->cl_actc, cl_actlist) {
1311 		if (p->cl_f <= cur_time)
1312 			return (p);
1313 	}
1314 	return (NULL);
1315 }
1316 
1317 /*
1318  * service curve support functions
1319  *
1320  *  external service curve parameters
1321  *	m: bits/sec
1322  *	d: msec
1323  *  internal service curve parameters
1324  *	sm: (bytes/machclk tick) << SM_SHIFT
1325  *	ism: (machclk ticks/byte) << ISM_SHIFT
1326  *	dx: machclk ticks
1327  *
1328  * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits.  we
1329  * should be able to handle 100K-100Gbps linkspeed with 256 MHz machclk
1330  * frequency and at least 3 effective digits in decimal.
1331  *
1332  */
1333 #define	SM_SHIFT	24
1334 #define	ISM_SHIFT	14
1335 
1336 #define	SM_MASK		((1LL << SM_SHIFT) - 1)
1337 #define	ISM_MASK	((1LL << ISM_SHIFT) - 1)
1338 
1339 static __inline u_int64_t
1340 seg_x2y(u_int64_t x, u_int64_t sm)
1341 {
1342 	u_int64_t y;
1343 
1344 	/*
1345 	 * compute
1346 	 *	y = x * sm >> SM_SHIFT
1347 	 * but divide it for the upper and lower bits to avoid overflow
1348 	 */
1349 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
1350 	return (y);
1351 }
1352 
1353 static __inline u_int64_t
1354 seg_y2x(u_int64_t y, u_int64_t ism)
1355 {
1356 	u_int64_t x;
1357 
1358 	if (y == 0)
1359 		x = 0;
1360 	else if (ism == HT_INFINITY)
1361 		x = HT_INFINITY;
1362 	else {
1363 		x = (y >> ISM_SHIFT) * ism
1364 		    + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
1365 	}
1366 	return (x);
1367 }
1368 
1369 static __inline u_int64_t
1370 m2sm(u_int64_t m)
1371 {
1372 	u_int64_t sm;
1373 
1374 	sm = (m << SM_SHIFT) / 8 / machclk_freq;
1375 	return (sm);
1376 }
1377 
1378 static __inline u_int64_t
1379 m2ism(u_int64_t m)
1380 {
1381 	u_int64_t ism;
1382 
1383 	if (m == 0)
1384 		ism = HT_INFINITY;
1385 	else
1386 		ism = ((u_int64_t)machclk_freq << ISM_SHIFT) * 8 / m;
1387 	return (ism);
1388 }
1389 
1390 static __inline u_int64_t
1391 d2dx(u_int d)
1392 {
1393 	u_int64_t dx;
1394 
1395 	dx = ((u_int64_t)d * machclk_freq) / 1000;
1396 	return (dx);
1397 }
1398 
1399 static u_int64_t
1400 sm2m(u_int64_t sm)
1401 {
1402 	u_int64_t m;
1403 
1404 	m = (sm * 8 * machclk_freq) >> SM_SHIFT;
1405 	return (m);
1406 }
1407 
1408 static u_int
1409 dx2d(u_int64_t dx)
1410 {
1411 	u_int64_t d;
1412 
1413 	d = dx * 1000 / machclk_freq;
1414 	return ((u_int)d);
1415 }
1416 
1417 static void
1418 sc2isc(struct service_curve *sc, struct internal_sc *isc)
1419 {
1420 	isc->sm1 = m2sm(sc->m1);
1421 	isc->ism1 = m2ism(sc->m1);
1422 	isc->dx = d2dx(sc->d);
1423 	isc->dy = seg_x2y(isc->dx, isc->sm1);
1424 	isc->sm2 = m2sm(sc->m2);
1425 	isc->ism2 = m2ism(sc->m2);
1426 }
1427 
1428 /*
1429  * initialize the runtime service curve with the given internal
1430  * service curve starting at (x, y).
1431  */
1432 static void
1433 rtsc_init(struct runtime_sc *rtsc, struct internal_sc * isc, u_int64_t x,
1434     u_int64_t y)
1435 {
1436 	rtsc->x =	x;
1437 	rtsc->y =	y;
1438 	rtsc->sm1 =	isc->sm1;
1439 	rtsc->ism1 =	isc->ism1;
1440 	rtsc->dx =	isc->dx;
1441 	rtsc->dy =	isc->dy;
1442 	rtsc->sm2 =	isc->sm2;
1443 	rtsc->ism2 =	isc->ism2;
1444 }
1445 
1446 /*
1447  * calculate the y-projection of the runtime service curve by the
1448  * given x-projection value
1449  */
1450 static u_int64_t
1451 rtsc_y2x(struct runtime_sc *rtsc, u_int64_t y)
1452 {
1453 	u_int64_t	x;
1454 
1455 	if (y < rtsc->y)
1456 		x = rtsc->x;
1457 	else if (y <= rtsc->y + rtsc->dy) {
1458 		/* x belongs to the 1st segment */
1459 		if (rtsc->dy == 0)
1460 			x = rtsc->x + rtsc->dx;
1461 		else
1462 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
1463 	} else {
1464 		/* x belongs to the 2nd segment */
1465 		x = rtsc->x + rtsc->dx
1466 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
1467 	}
1468 	return (x);
1469 }
1470 
1471 static u_int64_t
1472 rtsc_x2y(struct runtime_sc *rtsc, u_int64_t x)
1473 {
1474 	u_int64_t	y;
1475 
1476 	if (x <= rtsc->x)
1477 		y = rtsc->y;
1478 	else if (x <= rtsc->x + rtsc->dx)
1479 		/* y belongs to the 1st segment */
1480 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
1481 	else
1482 		/* y belongs to the 2nd segment */
1483 		y = rtsc->y + rtsc->dy
1484 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
1485 	return (y);
1486 }
1487 
1488 /*
1489  * update the runtime service curve by taking the minimum of the current
1490  * runtime service curve and the service curve starting at (x, y).
1491  */
1492 static void
1493 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u_int64_t x,
1494     u_int64_t y)
1495 {
1496 	u_int64_t	y1, y2, dx, dy;
1497 
1498 	if (isc->sm1 <= isc->sm2) {
1499 		/* service curve is convex */
1500 		y1 = rtsc_x2y(rtsc, x);
1501 		if (y1 < y)
1502 			/* the current rtsc is smaller */
1503 			return;
1504 		rtsc->x = x;
1505 		rtsc->y = y;
1506 		return;
1507 	}
1508 
1509 	/*
1510 	 * service curve is concave
1511 	 * compute the two y values of the current rtsc
1512 	 *	y1: at x
1513 	 *	y2: at (x + dx)
1514 	 */
1515 	y1 = rtsc_x2y(rtsc, x);
1516 	if (y1 <= y) {
1517 		/* rtsc is below isc, no change to rtsc */
1518 		return;
1519 	}
1520 
1521 	y2 = rtsc_x2y(rtsc, x + isc->dx);
1522 	if (y2 >= y + isc->dy) {
1523 		/* rtsc is above isc, replace rtsc by isc */
1524 		rtsc->x = x;
1525 		rtsc->y = y;
1526 		rtsc->dx = isc->dx;
1527 		rtsc->dy = isc->dy;
1528 		return;
1529 	}
1530 
1531 	/*
1532 	 * the two curves intersect
1533 	 * compute the offsets (dx, dy) using the reverse
1534 	 * function of seg_x2y()
1535 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
1536 	 */
1537 	dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2);
1538 	/*
1539 	 * check if (x, y1) belongs to the 1st segment of rtsc.
1540 	 * if so, add the offset.
1541 	 */
1542 	if (rtsc->x + rtsc->dx > x)
1543 		dx += rtsc->x + rtsc->dx - x;
1544 	dy = seg_x2y(dx, isc->sm1);
1545 
1546 	rtsc->x = x;
1547 	rtsc->y = y;
1548 	rtsc->dx = dx;
1549 	rtsc->dy = dy;
1550 	return;
1551 }
1552 
1553 static void
1554 get_class_stats_v0(struct hfsc_classstats_v0 *sp, struct hfsc_class *cl)
1555 {
1556 	sp->class_id = cl->cl_id;
1557 	sp->class_handle = cl->cl_handle;
1558 
1559 #define SATU32(x)	(u_int32_t)uqmin((x), UINT_MAX)
1560 
1561 	if (cl->cl_rsc != NULL) {
1562 		sp->rsc.m1 = SATU32(sm2m(cl->cl_rsc->sm1));
1563 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1564 		sp->rsc.m2 = SATU32(sm2m(cl->cl_rsc->sm2));
1565 	} else {
1566 		sp->rsc.m1 = 0;
1567 		sp->rsc.d = 0;
1568 		sp->rsc.m2 = 0;
1569 	}
1570 	if (cl->cl_fsc != NULL) {
1571 		sp->fsc.m1 = SATU32(sm2m(cl->cl_fsc->sm1));
1572 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1573 		sp->fsc.m2 = SATU32(sm2m(cl->cl_fsc->sm2));
1574 	} else {
1575 		sp->fsc.m1 = 0;
1576 		sp->fsc.d = 0;
1577 		sp->fsc.m2 = 0;
1578 	}
1579 	if (cl->cl_usc != NULL) {
1580 		sp->usc.m1 = SATU32(sm2m(cl->cl_usc->sm1));
1581 		sp->usc.d = dx2d(cl->cl_usc->dx);
1582 		sp->usc.m2 = SATU32(sm2m(cl->cl_usc->sm2));
1583 	} else {
1584 		sp->usc.m1 = 0;
1585 		sp->usc.d = 0;
1586 		sp->usc.m2 = 0;
1587 	}
1588 
1589 #undef SATU32
1590 
1591 	sp->total = cl->cl_total;
1592 	sp->cumul = cl->cl_cumul;
1593 
1594 	sp->d = cl->cl_d;
1595 	sp->e = cl->cl_e;
1596 	sp->vt = cl->cl_vt;
1597 	sp->f = cl->cl_f;
1598 
1599 	sp->initvt = cl->cl_initvt;
1600 	sp->vtperiod = cl->cl_vtperiod;
1601 	sp->parentperiod = cl->cl_parentperiod;
1602 	sp->nactive = cl->cl_nactive;
1603 	sp->vtoff = cl->cl_vtoff;
1604 	sp->cvtmax = cl->cl_cvtmax;
1605 	sp->myf = cl->cl_myf;
1606 	sp->cfmin = cl->cl_cfmin;
1607 	sp->cvtmin = cl->cl_cvtmin;
1608 	sp->myfadj = cl->cl_myfadj;
1609 	sp->vtadj = cl->cl_vtadj;
1610 
1611 	sp->cur_time = read_machclk();
1612 	sp->machclk_freq = machclk_freq;
1613 
1614 	sp->qlength = qlen(cl->cl_q);
1615 	sp->qlimit = qlimit(cl->cl_q);
1616 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1617 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1618 	sp->period = cl->cl_stats.period;
1619 
1620 	sp->qtype = qtype(cl->cl_q);
1621 #ifdef ALTQ_RED
1622 	if (q_is_red(cl->cl_q))
1623 		red_getstats(cl->cl_red, &sp->red[0]);
1624 #endif
1625 #ifdef ALTQ_RIO
1626 	if (q_is_rio(cl->cl_q))
1627 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1628 #endif
1629 #ifdef ALTQ_CODEL
1630 	if (q_is_codel(cl->cl_q))
1631 		codel_getstats(cl->cl_codel, &sp->codel);
1632 #endif
1633 }
1634 
1635 static void
1636 get_class_stats_v1(struct hfsc_classstats_v1 *sp, struct hfsc_class *cl)
1637 {
1638 	sp->class_id = cl->cl_id;
1639 	sp->class_handle = cl->cl_handle;
1640 
1641 	if (cl->cl_rsc != NULL) {
1642 		sp->rsc.m1 = sm2m(cl->cl_rsc->sm1);
1643 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1644 		sp->rsc.m2 = sm2m(cl->cl_rsc->sm2);
1645 	} else {
1646 		sp->rsc.m1 = 0;
1647 		sp->rsc.d = 0;
1648 		sp->rsc.m2 = 0;
1649 	}
1650 	if (cl->cl_fsc != NULL) {
1651 		sp->fsc.m1 = sm2m(cl->cl_fsc->sm1);
1652 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1653 		sp->fsc.m2 = sm2m(cl->cl_fsc->sm2);
1654 	} else {
1655 		sp->fsc.m1 = 0;
1656 		sp->fsc.d = 0;
1657 		sp->fsc.m2 = 0;
1658 	}
1659 	if (cl->cl_usc != NULL) {
1660 		sp->usc.m1 = sm2m(cl->cl_usc->sm1);
1661 		sp->usc.d = dx2d(cl->cl_usc->dx);
1662 		sp->usc.m2 = sm2m(cl->cl_usc->sm2);
1663 	} else {
1664 		sp->usc.m1 = 0;
1665 		sp->usc.d = 0;
1666 		sp->usc.m2 = 0;
1667 	}
1668 
1669 	sp->total = cl->cl_total;
1670 	sp->cumul = cl->cl_cumul;
1671 
1672 	sp->d = cl->cl_d;
1673 	sp->e = cl->cl_e;
1674 	sp->vt = cl->cl_vt;
1675 	sp->f = cl->cl_f;
1676 
1677 	sp->initvt = cl->cl_initvt;
1678 	sp->vtperiod = cl->cl_vtperiod;
1679 	sp->parentperiod = cl->cl_parentperiod;
1680 	sp->nactive = cl->cl_nactive;
1681 	sp->vtoff = cl->cl_vtoff;
1682 	sp->cvtmax = cl->cl_cvtmax;
1683 	sp->myf = cl->cl_myf;
1684 	sp->cfmin = cl->cl_cfmin;
1685 	sp->cvtmin = cl->cl_cvtmin;
1686 	sp->myfadj = cl->cl_myfadj;
1687 	sp->vtadj = cl->cl_vtadj;
1688 
1689 	sp->cur_time = read_machclk();
1690 	sp->machclk_freq = machclk_freq;
1691 
1692 	sp->qlength = qlen(cl->cl_q);
1693 	sp->qlimit = qlimit(cl->cl_q);
1694 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1695 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1696 	sp->period = cl->cl_stats.period;
1697 
1698 	sp->qtype = qtype(cl->cl_q);
1699 #ifdef ALTQ_RED
1700 	if (q_is_red(cl->cl_q))
1701 		red_getstats(cl->cl_red, &sp->red[0]);
1702 #endif
1703 #ifdef ALTQ_RIO
1704 	if (q_is_rio(cl->cl_q))
1705 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1706 #endif
1707 #ifdef ALTQ_CODEL
1708 	if (q_is_codel(cl->cl_q))
1709 		codel_getstats(cl->cl_codel, &sp->codel);
1710 #endif
1711 }
1712 
1713 /* convert a class handle to the corresponding class pointer */
1714 static struct hfsc_class *
1715 clh_to_clp(struct hfsc_if *hif, u_int32_t chandle)
1716 {
1717 	int i;
1718 	struct hfsc_class *cl;
1719 
1720 	if (chandle == 0)
1721 		return (NULL);
1722 	/*
1723 	 * first, try optimistically the slot matching the lower bits of
1724 	 * the handle.  if it fails, do the linear table search.
1725 	 */
1726 	i = chandle % HFSC_MAX_CLASSES;
1727 	if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle)
1728 		return (cl);
1729 	for (i = 0; i < HFSC_MAX_CLASSES; i++)
1730 		if ((cl = hif->hif_class_tbl[i]) != NULL &&
1731 		    cl->cl_handle == chandle)
1732 			return (cl);
1733 	return (NULL);
1734 }
1735 
1736 #endif /* ALTQ_HFSC */
1737