xref: /dragonfly/sys/net/altq/altq_hfsc.c (revision e8c03636)
1 /*	$KAME: altq_hfsc.c,v 1.25 2004/04/17 10:54:48 kjc Exp $	*/
2 
3 /*
4  * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
5  *
6  * Permission to use, copy, modify, and distribute this software and
7  * its documentation is hereby granted (including for commercial or
8  * for-profit use), provided that both the copyright notice and this
9  * permission notice appear in all copies of the software, derivative
10  * works, or modified versions, and any portions thereof.
11  *
12  * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
13  * WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON PROVIDES THIS
14  * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
15  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
20  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
21  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
22  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
24  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
25  * DAMAGE.
26  *
27  * Carnegie Mellon encourages (but does not require) users of this
28  * software to return any improvements or extensions that they make,
29  * and to grant Carnegie Mellon the rights to redistribute these
30  * changes without encumbrance.
31  */
32 /*
33  * H-FSC is described in Proceedings of SIGCOMM'97,
34  * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing,
35  * Real-Time and Priority Service"
36  * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng.
37  *
38  * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing.
39  * when a class has an upperlimit, the fit-time is computed from the
40  * upperlimit service curve.  the link-sharing scheduler does not schedule
41  * a class whose fit-time exceeds the current time.
42  */
43 
44 #include "opt_altq.h"
45 #include "opt_inet.h"
46 #include "opt_inet6.h"
47 
48 #ifdef ALTQ_HFSC  /* hfsc is enabled by ALTQ_HFSC option in opt_altq.h */
49 
50 #include <sys/param.h>
51 #include <sys/malloc.h>
52 #include <sys/mbuf.h>
53 #include <sys/socket.h>
54 #include <sys/systm.h>
55 #include <sys/errno.h>
56 #include <sys/queue.h>
57 #include <sys/thread.h>
58 
59 #include <net/if.h>
60 #include <net/ifq_var.h>
61 #include <netinet/in.h>
62 
63 #include <net/pf/pfvar.h>
64 #include <net/altq/altq.h>
65 #include <net/altq/altq_hfsc.h>
66 
67 #include <sys/thread2.h>
68 
69 #define HFSC_SUBQ_INDEX		ALTQ_SUBQ_INDEX_DEFAULT
70 #define HFSC_LOCK(ifq) \
71     ALTQ_SQ_LOCK(&(ifq)->altq_subq[HFSC_SUBQ_INDEX])
72 #define HFSC_UNLOCK(ifq) \
73     ALTQ_SQ_UNLOCK(&(ifq)->altq_subq[HFSC_SUBQ_INDEX])
74 
75 /*
76  * function prototypes
77  */
78 static int	hfsc_clear_interface(struct hfsc_if *);
79 static int	hfsc_request(struct ifaltq_subque *, 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 *,
83 					    struct service_curve *,
84 					    struct service_curve *,
85 					    struct hfsc_class *, int, int, int);
86 static int	hfsc_class_destroy(struct hfsc_class *);
87 static struct hfsc_class *hfsc_nextclass(struct hfsc_class *);
88 static int	hfsc_enqueue(struct ifaltq_subque *, struct mbuf *,
89 			     struct altq_pktattr *);
90 static struct mbuf *hfsc_dequeue(struct ifaltq_subque *, int);
91 
92 static int	hfsc_addq(struct hfsc_class *, struct mbuf *);
93 static struct mbuf *hfsc_getq(struct hfsc_class *);
94 static struct mbuf *hfsc_pollq(struct hfsc_class *);
95 static void	hfsc_purgeq(struct hfsc_class *);
96 
97 static void	update_cfmin(struct hfsc_class *);
98 static void	set_active(struct hfsc_class *, int);
99 static void	set_passive(struct hfsc_class *);
100 
101 static void	init_ed(struct hfsc_class *, int);
102 static void	update_ed(struct hfsc_class *, int);
103 static void	update_d(struct hfsc_class *, int);
104 static void	init_vf(struct hfsc_class *, int);
105 static void	update_vf(struct hfsc_class *, int, uint64_t);
106 static ellist_t *ellist_alloc(void);
107 static void	ellist_destroy(ellist_t *);
108 static void	ellist_insert(struct hfsc_class *);
109 static void	ellist_remove(struct hfsc_class *);
110 static void	ellist_update(struct hfsc_class *);
111 struct hfsc_class *ellist_get_mindl(ellist_t *, uint64_t);
112 static actlist_t *actlist_alloc(void);
113 static void	actlist_destroy(actlist_t *);
114 static void	actlist_insert(struct hfsc_class *);
115 static void	actlist_remove(struct hfsc_class *);
116 static void	actlist_update(struct hfsc_class *);
117 
118 static struct hfsc_class *actlist_firstfit(struct hfsc_class *, uint64_t);
119 
120 static __inline uint64_t	seg_x2y(uint64_t, uint64_t);
121 static __inline uint64_t	seg_y2x(uint64_t, uint64_t);
122 static __inline uint64_t	m2sm(u_int);
123 static __inline uint64_t	m2ism(u_int);
124 static __inline uint64_t	d2dx(u_int);
125 static u_int			sm2m(uint64_t);
126 static u_int			dx2d(uint64_t);
127 
128 static void	sc2isc(struct service_curve *, struct internal_sc *);
129 static void	rtsc_init(struct runtime_sc *, struct internal_sc *,
130 			  uint64_t, uint64_t);
131 static uint64_t	rtsc_y2x(struct runtime_sc *, uint64_t);
132 static uint64_t	rtsc_x2y(struct runtime_sc *, uint64_t);
133 static void	rtsc_min(struct runtime_sc *, struct internal_sc *,
134 			 uint64_t, uint64_t);
135 
136 static void	get_class_stats(struct hfsc_classstats *, struct hfsc_class *);
137 static struct hfsc_class *clh_to_clp(struct hfsc_if *, uint32_t);
138 
139 /*
140  * macros
141  */
142 #define	is_a_parent_class(cl)	((cl)->cl_children != NULL)
143 
144 #define	HT_INFINITY	0xffffffffffffffffLL	/* infinite time value */
145 
146 int
147 hfsc_pfattach(struct pf_altq *a, struct ifaltq *ifq)
148 {
149 	return altq_attach(ifq, ALTQT_HFSC, a->altq_disc, ifq_mapsubq_default,
150 	    hfsc_enqueue, hfsc_dequeue, hfsc_request, NULL, NULL);
151 }
152 
153 int
154 hfsc_add_altq(struct pf_altq *a)
155 {
156 	struct hfsc_if *hif;
157 	struct ifnet *ifp;
158 
159 	if ((ifp = ifunit(a->ifname)) == NULL)
160 		return (EINVAL);
161 	if (!ifq_is_ready(&ifp->if_snd))
162 		return (ENODEV);
163 
164 	hif = kmalloc(sizeof(struct hfsc_if), M_ALTQ, M_WAITOK | M_ZERO);
165 
166 	hif->hif_eligible = ellist_alloc();
167 	hif->hif_ifq = &ifp->if_snd;
168 	ifq_purge_all(&ifp->if_snd);
169 
170 	/* keep the state in pf_altq */
171 	a->altq_disc = hif;
172 
173 	return (0);
174 }
175 
176 int
177 hfsc_remove_altq(struct pf_altq *a)
178 {
179 	struct hfsc_if *hif;
180 
181 	if ((hif = a->altq_disc) == NULL)
182 		return (EINVAL);
183 	a->altq_disc = NULL;
184 
185 	hfsc_clear_interface(hif);
186 	hfsc_class_destroy(hif->hif_rootclass);
187 
188 	ellist_destroy(hif->hif_eligible);
189 
190 	kfree(hif, M_ALTQ);
191 
192 	return (0);
193 }
194 
195 static int
196 hfsc_add_queue_locked(struct pf_altq *a, struct hfsc_if *hif)
197 {
198 	struct hfsc_class *cl, *parent;
199 	struct hfsc_opts *opts;
200 	struct service_curve rtsc, lssc, ulsc;
201 
202 	KKASSERT(a->qid != 0);
203 
204 	opts = &a->pq_u.hfsc_opts;
205 
206 	if (a->parent_qid == HFSC_NULLCLASS_HANDLE && hif->hif_rootclass == NULL)
207 		parent = NULL;
208 	else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL)
209 		return (EINVAL);
210 
211 	if (clh_to_clp(hif, a->qid) != NULL)
212 		return (EBUSY);
213 
214 	rtsc.m1 = opts->rtsc_m1;
215 	rtsc.d  = opts->rtsc_d;
216 	rtsc.m2 = opts->rtsc_m2;
217 	lssc.m1 = opts->lssc_m1;
218 	lssc.d  = opts->lssc_d;
219 	lssc.m2 = opts->lssc_m2;
220 	ulsc.m1 = opts->ulsc_m1;
221 	ulsc.d  = opts->ulsc_d;
222 	ulsc.m2 = opts->ulsc_m2;
223 
224 	cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc, parent, a->qlimit,
225 			       opts->flags, a->qid);
226 	if (cl == NULL)
227 		return (ENOMEM);
228 
229 	return (0);
230 }
231 
232 int
233 hfsc_add_queue(struct pf_altq *a)
234 {
235 	struct hfsc_if *hif;
236 	struct ifaltq *ifq;
237 	int error;
238 
239 	if (a->qid == 0)
240 		return (EINVAL);
241 
242 	/* XXX not MP safe */
243 	if ((hif = a->altq_disc) == NULL)
244 		return (EINVAL);
245 	ifq = hif->hif_ifq;
246 
247 	HFSC_LOCK(ifq);
248 	error = hfsc_add_queue_locked(a, hif);
249 	HFSC_UNLOCK(ifq);
250 
251 	return error;
252 }
253 
254 static int
255 hfsc_remove_queue_locked(struct pf_altq *a, struct hfsc_if *hif)
256 {
257 	struct hfsc_class *cl;
258 
259 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
260 		return (EINVAL);
261 
262 	return (hfsc_class_destroy(cl));
263 }
264 
265 int
266 hfsc_remove_queue(struct pf_altq *a)
267 {
268 	struct hfsc_if *hif;
269 	struct ifaltq *ifq;
270 	int error;
271 
272 	/* XXX not MP safe */
273 	if ((hif = a->altq_disc) == NULL)
274 		return (EINVAL);
275 	ifq = hif->hif_ifq;
276 
277 	HFSC_LOCK(ifq);
278 	error = hfsc_remove_queue_locked(a, hif);
279 	HFSC_UNLOCK(ifq);
280 
281 	return error;
282 }
283 
284 int
285 hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
286 {
287 	struct hfsc_if *hif;
288 	struct hfsc_class *cl;
289 	struct hfsc_classstats stats;
290 	struct ifaltq *ifq;
291 	int error = 0;
292 
293 	if (*nbytes < sizeof(stats))
294 		return (EINVAL);
295 
296 	/* XXX not MP safe */
297 	if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL)
298 		return (EBADF);
299 	ifq = hif->hif_ifq;
300 
301 	HFSC_LOCK(ifq);
302 
303 	if ((cl = clh_to_clp(hif, a->qid)) == NULL) {
304 		HFSC_UNLOCK(ifq);
305 		return (EINVAL);
306 	}
307 
308 	get_class_stats(&stats, cl);
309 
310 	HFSC_UNLOCK(ifq);
311 
312 	if ((error = copyout((caddr_t)&stats, ubuf, sizeof(stats))) != 0)
313 		return (error);
314 	*nbytes = sizeof(stats);
315 	return (0);
316 }
317 
318 /*
319  * bring the interface back to the initial state by discarding
320  * all the filters and classes except the root class.
321  */
322 static int
323 hfsc_clear_interface(struct hfsc_if *hif)
324 {
325 	struct hfsc_class *cl;
326 
327 	if (hif->hif_rootclass == NULL)
328 		return (0);
329 
330 
331 	/* clear out the classes */
332 	while ((cl = hif->hif_rootclass->cl_children) != NULL) {
333 		/*
334 		 * remove the first leaf class found in the hierarchy
335 		 * then start over
336 		 */
337 		for (; cl != NULL; cl = hfsc_nextclass(cl)) {
338 			if (!is_a_parent_class(cl)) {
339 				hfsc_class_destroy(cl);
340 				break;
341 			}
342 		}
343 	}
344 
345 	return (0);
346 }
347 
348 static int
349 hfsc_request(struct ifaltq_subque *ifsq, int req, void *arg)
350 {
351 	struct ifaltq *ifq = ifsq->ifsq_altq;
352 	struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc;
353 
354 	crit_enter();
355 	switch (req) {
356 	case ALTRQ_PURGE:
357 		if (ifsq_get_index(ifsq) == HFSC_SUBQ_INDEX) {
358 			hfsc_purge(hif);
359 		} else {
360 			/*
361 			 * Race happened, the unrelated subqueue was
362 			 * picked during the packet scheduler transition.
363 			 */
364 			ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
365 		}
366 		break;
367 	}
368 	crit_exit();
369 	return (0);
370 }
371 
372 /* discard all the queued packets on the interface */
373 static void
374 hfsc_purge(struct hfsc_if *hif)
375 {
376 	struct hfsc_class *cl;
377 
378 	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl)) {
379 		if (!qempty(cl->cl_q))
380 			hfsc_purgeq(cl);
381 	}
382 	if (ifq_is_enabled(hif->hif_ifq))
383 		ALTQ_SQ_CNTR_RESET(&hif->hif_ifq->altq_subq[HFSC_SUBQ_INDEX]);
384 }
385 
386 struct hfsc_class *
387 hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc,
388 		  struct service_curve *fsc, struct service_curve *usc,
389 		  struct hfsc_class *parent, int qlimit, int flags, int qid)
390 {
391 	struct hfsc_class *cl, *p;
392 	int i;
393 
394 	if (hif->hif_classes >= HFSC_MAX_CLASSES)
395 		return (NULL);
396 
397 #ifndef ALTQ_RED
398 	if (flags & HFCF_RED) {
399 #ifdef ALTQ_DEBUG
400 		kprintf("hfsc_class_create: RED not configured for HFSC!\n");
401 #endif
402 		return (NULL);
403 	}
404 #endif
405 
406 	cl = kmalloc(sizeof(*cl), M_ALTQ, M_WAITOK | M_ZERO);
407 	cl->cl_q = kmalloc(sizeof(*cl->cl_q), M_ALTQ, M_WAITOK | M_ZERO);
408 	cl->cl_actc = actlist_alloc();
409 
410 	if (qlimit == 0)
411 		qlimit = 50;  /* use default */
412 	qlimit(cl->cl_q) = qlimit;
413 	qtype(cl->cl_q) = Q_DROPTAIL;
414 	qlen(cl->cl_q) = 0;
415 	cl->cl_flags = flags;
416 #ifdef ALTQ_RED
417 	if (flags & (HFCF_RED|HFCF_RIO)) {
418 		int red_flags, red_pkttime;
419 		u_int m2;
420 
421 		m2 = 0;
422 		if (rsc != NULL && rsc->m2 > m2)
423 			m2 = rsc->m2;
424 		if (fsc != NULL && fsc->m2 > m2)
425 			m2 = fsc->m2;
426 		if (usc != NULL && usc->m2 > m2)
427 			m2 = usc->m2;
428 
429 		red_flags = 0;
430 		if (flags & HFCF_ECN)
431 			red_flags |= REDF_ECN;
432 #ifdef ALTQ_RIO
433 		if (flags & HFCF_CLEARDSCP)
434 			red_flags |= RIOF_CLEARDSCP;
435 #endif
436 		if (m2 < 8)
437 			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
438 		else
439 			red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu
440 				* 1000 * 1000 * 1000 / (m2 / 8);
441 		if (flags & HFCF_RED) {
442 			cl->cl_red = red_alloc(0, 0,
443 			    qlimit(cl->cl_q) * 10/100,
444 			    qlimit(cl->cl_q) * 30/100,
445 			    red_flags, red_pkttime);
446 			if (cl->cl_red != NULL)
447 				qtype(cl->cl_q) = Q_RED;
448 		}
449 #ifdef ALTQ_RIO
450 		else {
451 			cl->cl_red = (red_t *)rio_alloc(0, NULL,
452 			    red_flags, red_pkttime);
453 			if (cl->cl_red != NULL)
454 				qtype(cl->cl_q) = Q_RIO;
455 		}
456 #endif
457 	}
458 #endif /* ALTQ_RED */
459 
460 	if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
461 		cl->cl_rsc = kmalloc(sizeof(*cl->cl_rsc), M_ALTQ, M_WAITOK);
462 		sc2isc(rsc, cl->cl_rsc);
463 		rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0);
464 		rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0);
465 	}
466 	if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) {
467 		cl->cl_fsc = kmalloc(sizeof(*cl->cl_fsc), M_ALTQ, M_WAITOK);
468 		sc2isc(fsc, cl->cl_fsc);
469 		rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0);
470 	}
471 	if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) {
472 		cl->cl_usc = kmalloc(sizeof(*cl->cl_usc), M_ALTQ, M_WAITOK);
473 		sc2isc(usc, cl->cl_usc);
474 		rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0);
475 	}
476 
477 	cl->cl_id = hif->hif_classid++;
478 	cl->cl_handle = qid;
479 	cl->cl_hif = hif;
480 	cl->cl_parent = parent;
481 
482 	crit_enter();
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 		}
500 		if (i == HFSC_MAX_CLASSES) {
501 			crit_exit();
502 			goto err_ret;
503 		}
504 	}
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 if (parent->cl_children == NULL) {
513 		/* add this class to the children list of the parent */
514 		parent->cl_children = cl;
515 	} else {
516 		p = parent->cl_children;
517 		while (p->cl_siblings != NULL)
518 			p = p->cl_siblings;
519 		p->cl_siblings = cl;
520 	}
521 	crit_exit();
522 
523 	return (cl);
524 
525  err_ret:
526 	if (cl->cl_actc != NULL)
527 		actlist_destroy(cl->cl_actc);
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 	}
538 	if (cl->cl_fsc != NULL)
539 		kfree(cl->cl_fsc, M_ALTQ);
540 	if (cl->cl_rsc != NULL)
541 		kfree(cl->cl_rsc, M_ALTQ);
542 	if (cl->cl_usc != NULL)
543 		kfree(cl->cl_usc, M_ALTQ);
544 	if (cl->cl_q != NULL)
545 		kfree(cl->cl_q, M_ALTQ);
546 	kfree(cl, M_ALTQ);
547 	return (NULL);
548 }
549 
550 static int
551 hfsc_class_destroy(struct hfsc_class *cl)
552 {
553 	struct hfsc_if *hif;
554 	int i;
555 
556 	if (cl == NULL)
557 		return (0);
558 	hif = cl->cl_hif;
559 
560 	if (is_a_parent_class(cl))
561 		return (EBUSY);
562 
563 	crit_enter();
564 
565 	if (!qempty(cl->cl_q))
566 		hfsc_purgeq(cl);
567 
568 	if (cl->cl_parent == NULL) {
569 		/* this is root class */
570 	} else {
571 		struct hfsc_class *p = cl->cl_parent->cl_children;
572 
573 		if (p == cl) {
574 			cl->cl_parent->cl_children = cl->cl_siblings;
575 		} else {
576 			do {
577 				if (p->cl_siblings == cl) {
578 					p->cl_siblings = cl->cl_siblings;
579 					break;
580 				}
581 			} while ((p = p->cl_siblings) != NULL);
582 		}
583 		KKASSERT(p != NULL);
584 	}
585 
586 	for (i = 0; i < HFSC_MAX_CLASSES; i++) {
587 		if (hif->hif_class_tbl[i] == cl) {
588 			hif->hif_class_tbl[i] = NULL;
589 			break;
590 		}
591 	}
592 
593 	hif->hif_classes--;
594 	crit_exit();
595 
596 	actlist_destroy(cl->cl_actc);
597 
598 	if (cl->cl_red != NULL) {
599 #ifdef ALTQ_RIO
600 		if (q_is_rio(cl->cl_q))
601 			rio_destroy((rio_t *)cl->cl_red);
602 #endif
603 #ifdef ALTQ_RED
604 		if (q_is_red(cl->cl_q))
605 			red_destroy(cl->cl_red);
606 #endif
607 	}
608 
609 	if (cl == hif->hif_rootclass)
610 		hif->hif_rootclass = NULL;
611 	if (cl == hif->hif_defaultclass)
612 		hif->hif_defaultclass = NULL;
613 	if (cl == hif->hif_pollcache)
614 		hif->hif_pollcache = NULL;
615 
616 	if (cl->cl_usc != NULL)
617 		kfree(cl->cl_usc, M_ALTQ);
618 	if (cl->cl_fsc != NULL)
619 		kfree(cl->cl_fsc, M_ALTQ);
620 	if (cl->cl_rsc != NULL)
621 		kfree(cl->cl_rsc, M_ALTQ);
622 	kfree(cl->cl_q, M_ALTQ);
623 	kfree(cl, M_ALTQ);
624 
625 	return (0);
626 }
627 
628 /*
629  * hfsc_nextclass returns the next class in the tree.
630  *   usage:
631  *	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
632  *		do_something;
633  */
634 static struct hfsc_class *
635 hfsc_nextclass(struct hfsc_class *cl)
636 {
637 	if (cl->cl_children != NULL) {
638 		cl = cl->cl_children;
639 	} else if (cl->cl_siblings != NULL) {
640 		cl = cl->cl_siblings;
641 	} else {
642 		while ((cl = cl->cl_parent) != NULL) {
643 			if (cl->cl_siblings != NULL) {
644 				cl = cl->cl_siblings;
645 				break;
646 			}
647 		}
648 	}
649 
650 	return (cl);
651 }
652 
653 /*
654  * hfsc_enqueue is an enqueue function to be registered to
655  * (*altq_enqueue) in struct ifaltq.
656  */
657 static int
658 hfsc_enqueue(struct ifaltq_subque *ifsq, struct mbuf *m,
659     struct altq_pktattr *pktattr)
660 {
661 	struct ifaltq *ifq = ifsq->ifsq_altq;
662 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
663 	struct hfsc_class *cl;
664 	int len;
665 
666 	if (ifsq_get_index(ifsq) != HFSC_SUBQ_INDEX) {
667 		/*
668 		 * Race happened, the unrelated subqueue was
669 		 * picked during the packet scheduler transition.
670 		 */
671 		ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
672 		m_freem(m);
673 		return ENOBUFS;
674 	}
675 
676 	/* grab class set by classifier */
677 	M_ASSERTPKTHDR(m);
678 	crit_enter();
679 	if (m->m_pkthdr.fw_flags & PF_MBUF_STRUCTURE)
680 		cl = clh_to_clp(hif, m->m_pkthdr.pf.qid);
681 	else
682 		cl = NULL;
683 	if (cl == NULL || is_a_parent_class(cl)) {
684 		cl = hif->hif_defaultclass;
685 		if (cl == NULL) {
686 			m_freem(m);
687 			crit_exit();
688 			return (ENOBUFS);
689 		}
690 	}
691 	cl->cl_pktattr = NULL;
692 	len = m_pktlen(m);
693 	if (hfsc_addq(cl, m) != 0) {
694 		/* drop occurred.  mbuf was freed in hfsc_addq. */
695 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len);
696 		crit_exit();
697 		return (ENOBUFS);
698 	}
699 	ALTQ_SQ_CNTR_INC(ifsq, len);
700 	cl->cl_hif->hif_packets++;
701 
702 	/* successfully queued. */
703 	if (qlen(cl->cl_q) == 1)
704 		set_active(cl, m_pktlen(m));
705 	crit_exit();
706 	return (0);
707 }
708 
709 /*
710  * hfsc_dequeue is a dequeue function to be registered to
711  * (*altq_dequeue) in struct ifaltq.
712  *
713  * note: ALTDQ_POLL returns the next packet without removing the packet
714  *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
715  */
716 static struct mbuf *
717 hfsc_dequeue(struct ifaltq_subque *ifsq, int op)
718 {
719 	struct ifaltq *ifq = ifsq->ifsq_altq;
720 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
721 	struct hfsc_class *cl;
722 	struct mbuf *m;
723 	int len, next_len;
724 	int realtime = 0;
725 	uint64_t cur_time;
726 
727 	if (ifsq_get_index(ifsq) != HFSC_SUBQ_INDEX) {
728 		/*
729 		 * Race happened, the unrelated subqueue was
730 		 * picked during the packet scheduler transition.
731 		 */
732 		ifsq_classic_request(ifsq, ALTRQ_PURGE, NULL);
733 		return NULL;
734 	}
735 
736 	if (hif->hif_packets == 0) {
737 		/* no packet in the tree */
738 		return (NULL);
739 	}
740 
741 	crit_enter();
742 	cur_time = read_machclk();
743 
744 	if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) {
745 		cl = hif->hif_pollcache;
746 		hif->hif_pollcache = NULL;
747 		/* check if the class was scheduled by real-time criteria */
748 		if (cl->cl_rsc != NULL)
749 			realtime = (cl->cl_e <= cur_time);
750 	} else {
751 		/*
752 		 * if there are eligible classes, use real-time criteria.
753 		 * find the class with the minimum deadline among
754 		 * the eligible classes.
755 		 */
756 		if ((cl = ellist_get_mindl(hif->hif_eligible, cur_time)) != NULL) {
757 			realtime = 1;
758 		} else {
759 #ifdef ALTQ_DEBUG
760 			int fits = 0;
761 #endif
762 			/*
763 			 * use link-sharing criteria
764 			 * get the class with the minimum vt in the hierarchy
765 			 */
766 			cl = hif->hif_rootclass;
767 			while (is_a_parent_class(cl)) {
768 
769 				cl = actlist_firstfit(cl, cur_time);
770 				if (cl == NULL) {
771 #ifdef ALTQ_DEBUG
772 					if (fits > 0)
773 						kprintf("%d fit but none found\n",fits);
774 #endif
775 					m = NULL;
776 					goto done;
777 				}
778 				/*
779 				 * update parent's cl_cvtmin.
780 				 * don't update if the new vt is smaller.
781 				 */
782 				if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
783 					cl->cl_parent->cl_cvtmin = cl->cl_vt;
784 #ifdef ALTQ_DEBUG
785 				fits++;
786 #endif
787 			}
788 		}
789 
790 		if (op == ALTDQ_POLL) {
791 #ifdef foo
792 			/*
793 			 * Don't use poll cache; the poll/dequeue
794 			 * model is no longer applicable to SMP
795 			 * system.  e.g.
796 			 *    CPU-A            CPU-B
797 			 *      :                :
798 			 *    poll               :
799 			 *      :              poll
800 			 *    dequeue (+)        :
801 			 *
802 			 * The dequeue at (+) will hit the poll
803 			 * cache set by CPU-B.
804 			 */
805 			hif->hif_pollcache = cl;
806 #endif
807 			m = hfsc_pollq(cl);
808 			goto done;
809 		}
810 	}
811 
812 	m = hfsc_getq(cl);
813 	if (m == NULL)
814 		panic("hfsc_dequeue:");
815 	len = m_pktlen(m);
816 	cl->cl_hif->hif_packets--;
817 	ALTQ_SQ_CNTR_DEC(ifsq, len);
818 	PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len);
819 
820 	update_vf(cl, len, cur_time);
821 	if (realtime)
822 		cl->cl_cumul += len;
823 
824 	if (!qempty(cl->cl_q)) {
825 		if (cl->cl_rsc != NULL) {
826 			/* update ed */
827 			next_len = m_pktlen(qhead(cl->cl_q));
828 
829 			if (realtime)
830 				update_ed(cl, next_len);
831 			else
832 				update_d(cl, next_len);
833 		}
834 	} else {
835 		/* the class becomes passive */
836 		set_passive(cl);
837 	}
838 done:
839 	crit_exit();
840 	return (m);
841 }
842 
843 static int
844 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
845 {
846 
847 #ifdef ALTQ_RIO
848 	if (q_is_rio(cl->cl_q))
849 		return rio_addq((rio_t *)cl->cl_red, cl->cl_q,
850 				m, cl->cl_pktattr);
851 #endif
852 #ifdef ALTQ_RED
853 	if (q_is_red(cl->cl_q))
854 		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
855 #endif
856 	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
857 		m_freem(m);
858 		return (-1);
859 	}
860 
861 	if (cl->cl_flags & HFCF_CLEARDSCP)
862 		write_dsfield(m, cl->cl_pktattr, 0);
863 
864 	_addq(cl->cl_q, m);
865 
866 	return (0);
867 }
868 
869 static struct mbuf *
870 hfsc_getq(struct hfsc_class *cl)
871 {
872 #ifdef ALTQ_RIO
873 	if (q_is_rio(cl->cl_q))
874 		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
875 #endif
876 #ifdef ALTQ_RED
877 	if (q_is_red(cl->cl_q))
878 		return red_getq(cl->cl_red, cl->cl_q);
879 #endif
880 	return _getq(cl->cl_q);
881 }
882 
883 static struct mbuf *
884 hfsc_pollq(struct hfsc_class *cl)
885 {
886 	return qhead(cl->cl_q);
887 }
888 
889 static void
890 hfsc_purgeq(struct hfsc_class *cl)
891 {
892 	struct mbuf *m;
893 
894 	if (qempty(cl->cl_q))
895 		return;
896 
897 	while ((m = _getq(cl->cl_q)) != NULL) {
898 		ALTQ_SQ_CNTR_DEC(
899 		    &cl->cl_hif->hif_ifq->altq_subq[HFSC_SUBQ_INDEX],
900 		    m_pktlen(m));
901 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m));
902 		m_freem(m);
903 		cl->cl_hif->hif_packets--;
904 	}
905 	KKASSERT(qlen(cl->cl_q) == 0);
906 
907 	update_vf(cl, 0, 0);	/* remove cl from the actlist */
908 	set_passive(cl);
909 }
910 
911 static void
912 set_active(struct hfsc_class *cl, int len)
913 {
914 	if (cl->cl_rsc != NULL)
915 		init_ed(cl, len);
916 	if (cl->cl_fsc != NULL)
917 		init_vf(cl, len);
918 
919 	cl->cl_stats.period++;
920 }
921 
922 static void
923 set_passive(struct hfsc_class *cl)
924 {
925 	if (cl->cl_rsc != NULL)
926 		ellist_remove(cl);
927 
928 	/*
929 	 * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
930 	 * needs to be called explicitly to remove a class from actlist
931 	 */
932 }
933 
934 static void
935 init_ed(struct hfsc_class *cl, int next_len)
936 {
937 	uint64_t cur_time;
938 
939 	cur_time = read_machclk();
940 
941 	/* update the deadline curve */
942 	rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul);
943 
944 	/*
945 	 * update the eligible curve.
946 	 * for concave, it is equal to the deadline curve.
947 	 * for convex, it is a linear curve with slope m2.
948 	 */
949 	cl->cl_eligible = cl->cl_deadline;
950 	if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) {
951 		cl->cl_eligible.dx = 0;
952 		cl->cl_eligible.dy = 0;
953 	}
954 
955 	/* compute e and d */
956 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
957 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
958 
959 	ellist_insert(cl);
960 }
961 
962 static void
963 update_ed(struct hfsc_class *cl, int next_len)
964 {
965 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
966 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
967 
968 	ellist_update(cl);
969 }
970 
971 static void
972 update_d(struct hfsc_class *cl, int next_len)
973 {
974 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
975 }
976 
977 static void
978 init_vf(struct hfsc_class *cl, int len)
979 {
980 	struct hfsc_class *max_cl, *p;
981 	uint64_t vt, f, cur_time;
982 	int go_active;
983 
984 	cur_time = 0;
985 	go_active = 1;
986 	for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) {
987 		if (go_active && cl->cl_nactive++ == 0)
988 			go_active = 1;
989 		else
990 			go_active = 0;
991 
992 		if (go_active) {
993 			max_cl = actlist_last(cl->cl_parent->cl_actc);
994 			if (max_cl != NULL) {
995 				/*
996 				 * set vt to the average of the min and max
997 				 * classes.  if the parent's period didn't
998 				 * change, don't decrease vt of the class.
999 				 */
1000 				vt = max_cl->cl_vt;
1001 				if (cl->cl_parent->cl_cvtmin != 0)
1002 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
1003 
1004 				if (cl->cl_parent->cl_vtperiod !=
1005 				    cl->cl_parentperiod || vt > cl->cl_vt)
1006 					cl->cl_vt = vt;
1007 			} else {
1008 				/*
1009 				 * first child for a new parent backlog period.
1010 				 * add parent's cvtmax to vtoff of children
1011 				 * to make a new vt (vtoff + vt) larger than
1012 				 * the vt in the last period for all children.
1013 				 */
1014 				vt = cl->cl_parent->cl_cvtmax;
1015 				for (p = cl->cl_parent->cl_children; p != NULL;
1016 				     p = p->cl_siblings)
1017 					p->cl_vtoff += vt;
1018 				cl->cl_vt = 0;
1019 				cl->cl_parent->cl_cvtmax = 0;
1020 				cl->cl_parent->cl_cvtmin = 0;
1021 			}
1022 			cl->cl_initvt = cl->cl_vt;
1023 
1024 			/* update the virtual curve */
1025 			vt = cl->cl_vt + cl->cl_vtoff;
1026 			rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total);
1027 			if (cl->cl_virtual.x == vt) {
1028 				cl->cl_virtual.x -= cl->cl_vtoff;
1029 				cl->cl_vtoff = 0;
1030 			}
1031 			cl->cl_vtadj = 0;
1032 
1033 			cl->cl_vtperiod++;  /* increment vt period */
1034 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
1035 			if (cl->cl_parent->cl_nactive == 0)
1036 				cl->cl_parentperiod++;
1037 			cl->cl_f = 0;
1038 
1039 			actlist_insert(cl);
1040 
1041 			if (cl->cl_usc != NULL) {
1042 				/* class has upper limit curve */
1043 				if (cur_time == 0)
1044 					cur_time = read_machclk();
1045 
1046 				/* update the ulimit curve */
1047 				rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time,
1048 				    cl->cl_total);
1049 				/* compute myf */
1050 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
1051 				    cl->cl_total);
1052 				cl->cl_myfadj = 0;
1053 			}
1054 		}
1055 
1056 		if (cl->cl_myf > cl->cl_cfmin)
1057 			f = cl->cl_myf;
1058 		else
1059 			f = cl->cl_cfmin;
1060 		if (f != cl->cl_f) {
1061 			cl->cl_f = f;
1062 			update_cfmin(cl->cl_parent);
1063 		}
1064 	}
1065 }
1066 
1067 static void
1068 update_vf(struct hfsc_class *cl, int len, uint64_t cur_time)
1069 {
1070 	uint64_t f, myf_bound, delta;
1071 	int go_passive;
1072 
1073 	go_passive = qempty(cl->cl_q);
1074 
1075 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
1076 		cl->cl_total += len;
1077 
1078 		if (cl->cl_fsc == NULL || cl->cl_nactive == 0)
1079 			continue;
1080 
1081 		if (go_passive && --cl->cl_nactive == 0)
1082 			go_passive = 1;
1083 		else
1084 			go_passive = 0;
1085 
1086 		if (go_passive) {
1087 			/* no more active child, going passive */
1088 
1089 			/* update cvtmax of the parent class */
1090 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
1091 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
1092 
1093 			/* remove this class from the vt list */
1094 			actlist_remove(cl);
1095 
1096 			update_cfmin(cl->cl_parent);
1097 
1098 			continue;
1099 		}
1100 
1101 		/*
1102 		 * update vt and f
1103 		 */
1104 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
1105 		    - cl->cl_vtoff + cl->cl_vtadj;
1106 
1107 		/*
1108 		 * if vt of the class is smaller than cvtmin,
1109 		 * the class was skipped in the past due to non-fit.
1110 		 * if so, we need to adjust vtadj.
1111 		 */
1112 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
1113 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
1114 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
1115 		}
1116 
1117 		/* update the vt list */
1118 		actlist_update(cl);
1119 
1120 		if (cl->cl_usc != NULL) {
1121 			cl->cl_myf = cl->cl_myfadj
1122 			    + rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
1123 
1124 			/*
1125 			 * if myf lags behind by more than one clock tick
1126 			 * from the current time, adjust myfadj to prevent
1127 			 * a rate-limited class from going greedy.
1128 			 * in a steady state under rate-limiting, myf
1129 			 * fluctuates within one clock tick.
1130 			 */
1131 			myf_bound = cur_time - machclk_per_tick;
1132 			if (cl->cl_myf < myf_bound) {
1133 				delta = cur_time - cl->cl_myf;
1134 				cl->cl_myfadj += delta;
1135 				cl->cl_myf += delta;
1136 			}
1137 		}
1138 
1139 		/* cl_f is max(cl_myf, cl_cfmin) */
1140 		if (cl->cl_myf > cl->cl_cfmin)
1141 			f = cl->cl_myf;
1142 		else
1143 			f = cl->cl_cfmin;
1144 		if (f != cl->cl_f) {
1145 			cl->cl_f = f;
1146 			update_cfmin(cl->cl_parent);
1147 		}
1148 	}
1149 }
1150 
1151 static void
1152 update_cfmin(struct hfsc_class *cl)
1153 {
1154 	struct hfsc_class *p;
1155 	uint64_t cfmin;
1156 
1157 	if (TAILQ_EMPTY(cl->cl_actc)) {
1158 		cl->cl_cfmin = 0;
1159 		return;
1160 	}
1161 	cfmin = HT_INFINITY;
1162 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1163 		if (p->cl_f == 0) {
1164 			cl->cl_cfmin = 0;
1165 			return;
1166 		}
1167 		if (p->cl_f < cfmin)
1168 			cfmin = p->cl_f;
1169 	}
1170 	cl->cl_cfmin = cfmin;
1171 }
1172 
1173 /*
1174  * TAILQ based ellist and actlist implementation
1175  * (ion wanted to make a calendar queue based implementation)
1176  */
1177 /*
1178  * eligible list holds backlogged classes being sorted by their eligible times.
1179  * there is one eligible list per interface.
1180  */
1181 
1182 static ellist_t *
1183 ellist_alloc(void)
1184 {
1185 	ellist_t *head;
1186 
1187 	head = kmalloc(sizeof(*head), M_ALTQ, M_WAITOK);
1188 	TAILQ_INIT(head);
1189 	return (head);
1190 }
1191 
1192 static void
1193 ellist_destroy(ellist_t *head)
1194 {
1195 	kfree(head, M_ALTQ);
1196 }
1197 
1198 static void
1199 ellist_insert(struct hfsc_class *cl)
1200 {
1201 	struct hfsc_if *hif = cl->cl_hif;
1202 	struct hfsc_class *p;
1203 
1204 	/* check the last entry first */
1205 	if ((p = TAILQ_LAST(hif->hif_eligible, _eligible)) == NULL ||
1206 	    p->cl_e <= cl->cl_e) {
1207 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1208 		return;
1209 	}
1210 
1211 	TAILQ_FOREACH(p, hif->hif_eligible, cl_ellist) {
1212 		if (cl->cl_e < p->cl_e) {
1213 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1214 			return;
1215 		}
1216 	}
1217 	KKASSERT(0); /* should not reach here */
1218 }
1219 
1220 static void
1221 ellist_remove(struct hfsc_class *cl)
1222 {
1223 	struct hfsc_if *hif = cl->cl_hif;
1224 
1225 	TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1226 }
1227 
1228 static void
1229 ellist_update(struct hfsc_class *cl)
1230 {
1231 	struct hfsc_if *hif = cl->cl_hif;
1232 	struct hfsc_class *p, *last;
1233 
1234 	/*
1235 	 * the eligible time of a class increases monotonically.
1236 	 * if the next entry has a larger eligible time, nothing to do.
1237 	 */
1238 	p = TAILQ_NEXT(cl, cl_ellist);
1239 	if (p == NULL || cl->cl_e <= p->cl_e)
1240 		return;
1241 
1242 	/* check the last entry */
1243 	last = TAILQ_LAST(hif->hif_eligible, _eligible);
1244 	KKASSERT(last != NULL);
1245 	if (last->cl_e <= cl->cl_e) {
1246 		TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1247 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1248 		return;
1249 	}
1250 
1251 	/*
1252 	 * the new position must be between the next entry
1253 	 * and the last entry
1254 	 */
1255 	while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) {
1256 		if (cl->cl_e < p->cl_e) {
1257 			TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1258 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1259 			return;
1260 		}
1261 	}
1262 	KKASSERT(0); /* should not reach here */
1263 }
1264 
1265 /* find the class with the minimum deadline among the eligible classes */
1266 struct hfsc_class *
1267 ellist_get_mindl(ellist_t *head, uint64_t cur_time)
1268 {
1269 	struct hfsc_class *p, *cl = NULL;
1270 
1271 	TAILQ_FOREACH(p, head, cl_ellist) {
1272 		if (p->cl_e > cur_time)
1273 			break;
1274 		if (cl == NULL || p->cl_d < cl->cl_d)
1275 			cl = p;
1276 	}
1277 	return (cl);
1278 }
1279 
1280 /*
1281  * active children list holds backlogged child classes being sorted
1282  * by their virtual time.
1283  * each intermediate class has one active children list.
1284  */
1285 static actlist_t *
1286 actlist_alloc(void)
1287 {
1288 	actlist_t *head;
1289 
1290 	head = kmalloc(sizeof(*head), M_ALTQ, M_WAITOK);
1291 	TAILQ_INIT(head);
1292 	return (head);
1293 }
1294 
1295 static void
1296 actlist_destroy(actlist_t *head)
1297 {
1298 	kfree(head, M_ALTQ);
1299 }
1300 static void
1301 actlist_insert(struct hfsc_class *cl)
1302 {
1303 	struct hfsc_class *p;
1304 
1305 	/* check the last entry first */
1306 	if ((p = TAILQ_LAST(cl->cl_parent->cl_actc, _active)) == NULL
1307 	    || p->cl_vt <= cl->cl_vt) {
1308 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1309 		return;
1310 	}
1311 
1312 	TAILQ_FOREACH(p, cl->cl_parent->cl_actc, cl_actlist) {
1313 		if (cl->cl_vt < p->cl_vt) {
1314 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1315 			return;
1316 		}
1317 	}
1318 	KKASSERT(0); /* should not reach here */
1319 }
1320 
1321 static void
1322 actlist_remove(struct hfsc_class *cl)
1323 {
1324 	TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1325 }
1326 
1327 static void
1328 actlist_update(struct hfsc_class *cl)
1329 {
1330 	struct hfsc_class *p, *last;
1331 
1332 	/*
1333 	 * the virtual time of a class increases monotonically during its
1334 	 * backlogged period.
1335 	 * if the next entry has a larger virtual time, nothing to do.
1336 	 */
1337 	p = TAILQ_NEXT(cl, cl_actlist);
1338 	if (p == NULL || cl->cl_vt < p->cl_vt)
1339 		return;
1340 
1341 	/* check the last entry */
1342 	last = TAILQ_LAST(cl->cl_parent->cl_actc, _active);
1343 	KKASSERT(last != NULL);
1344 	if (last->cl_vt <= cl->cl_vt) {
1345 		TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1346 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1347 		return;
1348 	}
1349 
1350 	/*
1351 	 * the new position must be between the next entry
1352 	 * and the last entry
1353 	 */
1354 	while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) {
1355 		if (cl->cl_vt < p->cl_vt) {
1356 			TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1357 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1358 			return;
1359 		}
1360 	}
1361 	KKASSERT(0); /* should not reach here */
1362 }
1363 
1364 static struct hfsc_class *
1365 actlist_firstfit(struct hfsc_class *cl, uint64_t cur_time)
1366 {
1367 	struct hfsc_class *p;
1368 
1369 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1370 		if (p->cl_f <= cur_time)
1371 			return (p);
1372 	}
1373 	return (NULL);
1374 }
1375 
1376 /*
1377  * service curve support functions
1378  *
1379  *  external service curve parameters
1380  *	m: bits/sec
1381  *	d: msec
1382  *  internal service curve parameters
1383  *	sm: (bytes/tsc_interval) << SM_SHIFT
1384  *	ism: (tsc_count/byte) << ISM_SHIFT
1385  *	dx: tsc_count
1386  *
1387  * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits.
1388  * we should be able to handle 100K-1Gbps linkspeed with 200Hz-1GHz CPU
1389  * speed.  SM_SHIFT and ISM_SHIFT are selected to have at least 3 effective
1390  * digits in decimal using the following table.
1391  *
1392  *  bits/sec    100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
1393  *  ----------+-------------------------------------------------------
1394  *  bytes/nsec  12.5e-6    125e-6     1250e-6    12500e-6   125000e-6
1395  *  sm(500MHz)  25.0e-6    250e-6     2500e-6    25000e-6   250000e-6
1396  *  sm(200MHz)  62.5e-6    625e-6     6250e-6    62500e-6   625000e-6
1397  *
1398  *  nsec/byte   80000      8000       800        80         8
1399  *  ism(500MHz) 40000      4000       400        40         4
1400  *  ism(200MHz) 16000      1600       160        16         1.6
1401  */
1402 #define	SM_SHIFT	24
1403 #define	ISM_SHIFT	10
1404 
1405 #define	SM_MASK		((1LL << SM_SHIFT) - 1)
1406 #define	ISM_MASK	((1LL << ISM_SHIFT) - 1)
1407 
1408 static __inline uint64_t
1409 seg_x2y(uint64_t x, uint64_t sm)
1410 {
1411 	uint64_t y;
1412 
1413 	/*
1414 	 * compute
1415 	 *	y = x * sm >> SM_SHIFT
1416 	 * but divide it for the upper and lower bits to avoid overflow
1417 	 */
1418 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
1419 	return (y);
1420 }
1421 
1422 static __inline uint64_t
1423 seg_y2x(uint64_t y, uint64_t ism)
1424 {
1425 	uint64_t x;
1426 
1427 	if (y == 0)
1428 		x = 0;
1429 	else if (ism == HT_INFINITY)
1430 		x = HT_INFINITY;
1431 	else
1432 		x = (y >> ISM_SHIFT) * ism + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
1433 
1434 	return (x);
1435 }
1436 
1437 static __inline uint64_t
1438 m2sm(u_int m)
1439 {
1440 	uint64_t sm;
1441 
1442 	sm = ((uint64_t)m << SM_SHIFT) / 8 / machclk_freq;
1443 	return (sm);
1444 }
1445 
1446 static __inline uint64_t
1447 m2ism(u_int m)
1448 {
1449 	uint64_t ism;
1450 
1451 	if (m == 0)
1452 		ism = HT_INFINITY;
1453 	else
1454 		ism = ((uint64_t)machclk_freq << ISM_SHIFT) * 8 / m;
1455 	return (ism);
1456 }
1457 
1458 static __inline uint64_t
1459 d2dx(u_int d)
1460 {
1461 	uint64_t dx;
1462 
1463 	dx = ((uint64_t)d * machclk_freq) / 1000;
1464 	return (dx);
1465 }
1466 
1467 static u_int
1468 sm2m(uint64_t sm)
1469 {
1470 	uint64_t m;
1471 
1472 	m = (sm * 8 * machclk_freq) >> SM_SHIFT;
1473 	return ((u_int)m);
1474 }
1475 
1476 static u_int
1477 dx2d(uint64_t dx)
1478 {
1479 	uint64_t d;
1480 
1481 	d = dx * 1000 / machclk_freq;
1482 	return ((u_int)d);
1483 }
1484 
1485 static void
1486 sc2isc(struct service_curve *sc, struct internal_sc *isc)
1487 {
1488 	isc->sm1 = m2sm(sc->m1);
1489 	isc->ism1 = m2ism(sc->m1);
1490 	isc->dx = d2dx(sc->d);
1491 	isc->dy = seg_x2y(isc->dx, isc->sm1);
1492 	isc->sm2 = m2sm(sc->m2);
1493 	isc->ism2 = m2ism(sc->m2);
1494 }
1495 
1496 /*
1497  * initialize the runtime service curve with the given internal
1498  * service curve starting at (x, y).
1499  */
1500 static void
1501 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1502 {
1503 	rtsc->x = x;
1504 	rtsc->y = y;
1505 	rtsc->sm1 = isc->sm1;
1506 	rtsc->ism1 = isc->ism1;
1507 	rtsc->dx = isc->dx;
1508 	rtsc->dy = isc->dy;
1509 	rtsc->sm2 = isc->sm2;
1510 	rtsc->ism2 = isc->ism2;
1511 }
1512 
1513 /*
1514  * calculate the y-projection of the runtime service curve by the
1515  * given x-projection value
1516  */
1517 static uint64_t
1518 rtsc_y2x(struct runtime_sc *rtsc, uint64_t y)
1519 {
1520 	uint64_t x;
1521 
1522 	if (y < rtsc->y) {
1523 		x = rtsc->x;
1524 	} else if (y <= rtsc->y + rtsc->dy) {
1525 		/* x belongs to the 1st segment */
1526 		if (rtsc->dy == 0)
1527 			x = rtsc->x + rtsc->dx;
1528 		else
1529 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
1530 	} else {
1531 		/* x belongs to the 2nd segment */
1532 		x = rtsc->x + rtsc->dx
1533 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
1534 	}
1535 	return (x);
1536 }
1537 
1538 static uint64_t
1539 rtsc_x2y(struct runtime_sc *rtsc, uint64_t x)
1540 {
1541 	uint64_t y;
1542 
1543 	if (x <= rtsc->x) {
1544 		y = rtsc->y;
1545 	} else if (x <= rtsc->x + rtsc->dx) {
1546 		/* y belongs to the 1st segment */
1547 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
1548 	} else
1549 		/* y belongs to the 2nd segment */
1550 		y = rtsc->y + rtsc->dy
1551 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
1552 	return (y);
1553 }
1554 
1555 /*
1556  * update the runtime service curve by taking the minimum of the current
1557  * runtime service curve and the service curve starting at (x, y).
1558  */
1559 static void
1560 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1561 {
1562 	uint64_t y1, y2, dx, dy;
1563 
1564 	if (isc->sm1 <= isc->sm2) {
1565 		/* service curve is convex */
1566 		y1 = rtsc_x2y(rtsc, x);
1567 		if (y1 < y)
1568 			/* the current rtsc is smaller */
1569 			return;
1570 		rtsc->x = x;
1571 		rtsc->y = y;
1572 		return;
1573 	}
1574 
1575 	/*
1576 	 * service curve is concave
1577 	 * compute the two y values of the current rtsc
1578 	 *	y1: at x
1579 	 *	y2: at (x + dx)
1580 	 */
1581 	y1 = rtsc_x2y(rtsc, x);
1582 	if (y1 <= y) {
1583 		/* rtsc is below isc, no change to rtsc */
1584 		return;
1585 	}
1586 
1587 	y2 = rtsc_x2y(rtsc, x + isc->dx);
1588 	if (y2 >= y + isc->dy) {
1589 		/* rtsc is above isc, replace rtsc by isc */
1590 		rtsc->x = x;
1591 		rtsc->y = y;
1592 		rtsc->dx = isc->dx;
1593 		rtsc->dy = isc->dy;
1594 		return;
1595 	}
1596 
1597 	/*
1598 	 * the two curves intersect
1599 	 * compute the offsets (dx, dy) using the reverse
1600 	 * function of seg_x2y()
1601 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
1602 	 */
1603 	dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2);
1604 	/*
1605 	 * check if (x, y1) belongs to the 1st segment of rtsc.
1606 	 * if so, add the offset.
1607 	 */
1608 	if (rtsc->x + rtsc->dx > x)
1609 		dx += rtsc->x + rtsc->dx - x;
1610 	dy = seg_x2y(dx, isc->sm1);
1611 
1612 	rtsc->x = x;
1613 	rtsc->y = y;
1614 	rtsc->dx = dx;
1615 	rtsc->dy = dy;
1616 }
1617 
1618 static void
1619 get_class_stats(struct hfsc_classstats *sp, struct hfsc_class *cl)
1620 {
1621 	sp->class_id = cl->cl_id;
1622 	sp->class_handle = cl->cl_handle;
1623 
1624 	if (cl->cl_rsc != NULL) {
1625 		sp->rsc.m1 = sm2m(cl->cl_rsc->sm1);
1626 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1627 		sp->rsc.m2 = sm2m(cl->cl_rsc->sm2);
1628 	} else {
1629 		sp->rsc.m1 = 0;
1630 		sp->rsc.d = 0;
1631 		sp->rsc.m2 = 0;
1632 	}
1633 	if (cl->cl_fsc != NULL) {
1634 		sp->fsc.m1 = sm2m(cl->cl_fsc->sm1);
1635 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1636 		sp->fsc.m2 = sm2m(cl->cl_fsc->sm2);
1637 	} else {
1638 		sp->fsc.m1 = 0;
1639 		sp->fsc.d = 0;
1640 		sp->fsc.m2 = 0;
1641 	}
1642 	if (cl->cl_usc != NULL) {
1643 		sp->usc.m1 = sm2m(cl->cl_usc->sm1);
1644 		sp->usc.d = dx2d(cl->cl_usc->dx);
1645 		sp->usc.m2 = sm2m(cl->cl_usc->sm2);
1646 	} else {
1647 		sp->usc.m1 = 0;
1648 		sp->usc.d = 0;
1649 		sp->usc.m2 = 0;
1650 	}
1651 
1652 	sp->total = cl->cl_total;
1653 	sp->cumul = cl->cl_cumul;
1654 
1655 	sp->d = cl->cl_d;
1656 	sp->e = cl->cl_e;
1657 	sp->vt = cl->cl_vt;
1658 	sp->f = cl->cl_f;
1659 
1660 	sp->initvt = cl->cl_initvt;
1661 	sp->vtperiod = cl->cl_vtperiod;
1662 	sp->parentperiod = cl->cl_parentperiod;
1663 	sp->nactive = cl->cl_nactive;
1664 	sp->vtoff = cl->cl_vtoff;
1665 	sp->cvtmax = cl->cl_cvtmax;
1666 	sp->myf = cl->cl_myf;
1667 	sp->cfmin = cl->cl_cfmin;
1668 	sp->cvtmin = cl->cl_cvtmin;
1669 	sp->myfadj = cl->cl_myfadj;
1670 	sp->vtadj = cl->cl_vtadj;
1671 
1672 	sp->cur_time = read_machclk();
1673 	sp->machclk_freq = machclk_freq;
1674 
1675 	sp->qlength = qlen(cl->cl_q);
1676 	sp->qlimit = qlimit(cl->cl_q);
1677 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1678 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1679 	sp->period = cl->cl_stats.period;
1680 
1681 	sp->qtype = qtype(cl->cl_q);
1682 #ifdef ALTQ_RED
1683 	if (q_is_red(cl->cl_q))
1684 		red_getstats(cl->cl_red, &sp->red[0]);
1685 #endif
1686 #ifdef ALTQ_RIO
1687 	if (q_is_rio(cl->cl_q))
1688 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1689 #endif
1690 }
1691 
1692 /* convert a class handle to the corresponding class pointer */
1693 static struct hfsc_class *
1694 clh_to_clp(struct hfsc_if *hif, uint32_t chandle)
1695 {
1696 	int i;
1697 	struct hfsc_class *cl;
1698 
1699 	if (chandle == 0)
1700 		return (NULL);
1701 	/*
1702 	 * first, try optimistically the slot matching the lower bits of
1703 	 * the handle.  if it fails, do the linear table search.
1704 	 */
1705 	i = chandle % HFSC_MAX_CLASSES;
1706 	if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle)
1707 		return (cl);
1708 	for (i = 0; i < HFSC_MAX_CLASSES; i++)
1709 		if ((cl = hif->hif_class_tbl[i]) != NULL &&
1710 		    cl->cl_handle == chandle)
1711 			return (cl);
1712 	return (NULL);
1713 }
1714 
1715 #endif /* ALTQ_HFSC */
1716