xref: /dragonfly/sys/net/altq/altq_hfsc.c (revision 1bf4b486)
1 /*	$KAME: altq_hfsc.c,v 1.25 2004/04/17 10:54:48 kjc Exp $	*/
2 /*	$DragonFly: src/sys/net/altq/altq_hfsc.c,v 1.4 2005/06/03 18:20:36 swildner Exp $ */
3 
4 /*
5  * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
6  *
7  * Permission to use, copy, modify, and distribute this software and
8  * its documentation is hereby granted (including for commercial or
9  * for-profit use), provided that both the copyright notice and this
10  * permission notice appear in all copies of the software, derivative
11  * works, or modified versions, and any portions thereof.
12  *
13  * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
14  * WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON PROVIDES THIS
15  * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
16  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18  * DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
21  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
22  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
23  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
25  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
26  * DAMAGE.
27  *
28  * Carnegie Mellon encourages (but does not require) users of this
29  * software to return any improvements or extensions that they make,
30  * and to grant Carnegie Mellon the rights to redistribute these
31  * changes without encumbrance.
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 #include <sys/thread.h>
59 
60 #include <net/if.h>
61 #include <net/ifq_var.h>
62 #include <netinet/in.h>
63 
64 #include <net/pf/pfvar.h>
65 #include <net/altq/altq.h>
66 #include <net/altq/altq_hfsc.h>
67 
68 #include <sys/thread2.h>
69 
70 /*
71  * function prototypes
72  */
73 static int	hfsc_clear_interface(struct hfsc_if *);
74 static int	hfsc_request(struct ifaltq *, int, void *);
75 static void	hfsc_purge(struct hfsc_if *);
76 static struct hfsc_class *hfsc_class_create(struct hfsc_if *,
77 					    struct service_curve *,
78 					    struct service_curve *,
79 					    struct service_curve *,
80 					    struct hfsc_class *, int, int, int);
81 static int	hfsc_class_destroy(struct hfsc_class *);
82 static struct hfsc_class *hfsc_nextclass(struct hfsc_class *);
83 static int	hfsc_enqueue(struct ifaltq *, struct mbuf *,
84 			     struct altq_pktattr *);
85 static struct mbuf *hfsc_dequeue(struct ifaltq *, int);
86 
87 static int	hfsc_addq(struct hfsc_class *, struct mbuf *);
88 static struct mbuf *hfsc_getq(struct hfsc_class *);
89 static struct mbuf *hfsc_pollq(struct hfsc_class *);
90 static void	hfsc_purgeq(struct hfsc_class *);
91 
92 static void	update_cfmin(struct hfsc_class *);
93 static void	set_active(struct hfsc_class *, int);
94 static void	set_passive(struct hfsc_class *);
95 
96 static void	init_ed(struct hfsc_class *, int);
97 static void	update_ed(struct hfsc_class *, int);
98 static void	update_d(struct hfsc_class *, int);
99 static void	init_vf(struct hfsc_class *, int);
100 static void	update_vf(struct hfsc_class *, int, uint64_t);
101 static ellist_t *ellist_alloc(void);
102 static void	ellist_destroy(ellist_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 *ellist_get_mindl(ellist_t *, uint64_t);
107 static actlist_t *actlist_alloc(void);
108 static void	actlist_destroy(actlist_t *);
109 static void	actlist_insert(struct hfsc_class *);
110 static void	actlist_remove(struct hfsc_class *);
111 static void	actlist_update(struct hfsc_class *);
112 
113 static struct hfsc_class *actlist_firstfit(struct hfsc_class *, uint64_t);
114 
115 static __inline uint64_t	seg_x2y(uint64_t, uint64_t);
116 static __inline uint64_t	seg_y2x(uint64_t, uint64_t);
117 static __inline uint64_t	m2sm(u_int);
118 static __inline uint64_t	m2ism(u_int);
119 static __inline uint64_t	d2dx(u_int);
120 static u_int			sm2m(uint64_t);
121 static u_int			dx2d(uint64_t);
122 
123 static void	sc2isc(struct service_curve *, struct internal_sc *);
124 static void	rtsc_init(struct runtime_sc *, struct internal_sc *,
125 			  uint64_t, uint64_t);
126 static uint64_t	rtsc_y2x(struct runtime_sc *, uint64_t);
127 static uint64_t	rtsc_x2y(struct runtime_sc *, uint64_t);
128 static void	rtsc_min(struct runtime_sc *, struct internal_sc *,
129 			 uint64_t, uint64_t);
130 
131 static void	get_class_stats(struct hfsc_classstats *, struct hfsc_class *);
132 static struct hfsc_class *clh_to_clp(struct hfsc_if *, uint32_t);
133 
134 /*
135  * macros
136  */
137 #define	is_a_parent_class(cl)	((cl)->cl_children != NULL)
138 
139 #define	HT_INFINITY	0xffffffffffffffffLL	/* infinite time value */
140 
141 int
142 hfsc_pfattach(struct pf_altq *a)
143 {
144 	struct ifnet *ifp;
145 	int error;
146 
147 	if ((ifp = ifunit(a->ifname)) == NULL || a->altq_disc == NULL)
148 		return (EINVAL);
149 	crit_enter();
150 	error = altq_attach(&ifp->if_snd, ALTQT_HFSC, a->altq_disc,
151 	    hfsc_enqueue, hfsc_dequeue, hfsc_request, NULL, NULL);
152 	crit_exit();
153 	return (error);
154 }
155 
156 int
157 hfsc_add_altq(struct pf_altq *a)
158 {
159 	struct hfsc_if *hif;
160 	struct ifnet *ifp;
161 
162 	if ((ifp = ifunit(a->ifname)) == NULL)
163 		return (EINVAL);
164 	if (!ifq_is_ready(&ifp->if_snd))
165 		return (ENODEV);
166 
167 	hif = malloc(sizeof(struct hfsc_if), M_ALTQ, M_WAITOK | M_ZERO);
168 
169 	hif->hif_eligible = ellist_alloc();
170 	hif->hif_ifq = &ifp->if_snd;
171 
172 	/* keep the state in pf_altq */
173 	a->altq_disc = hif;
174 
175 	return (0);
176 }
177 
178 int
179 hfsc_remove_altq(struct pf_altq *a)
180 {
181 	struct hfsc_if *hif;
182 
183 	if ((hif = a->altq_disc) == NULL)
184 		return (EINVAL);
185 	a->altq_disc = NULL;
186 
187 	hfsc_clear_interface(hif);
188 	hfsc_class_destroy(hif->hif_rootclass);
189 
190 	ellist_destroy(hif->hif_eligible);
191 
192 	free(hif, M_ALTQ);
193 
194 	return (0);
195 }
196 
197 int
198 hfsc_add_queue(struct pf_altq *a)
199 {
200 	struct hfsc_if *hif;
201 	struct hfsc_class *cl, *parent;
202 	struct hfsc_opts *opts;
203 	struct service_curve rtsc, lssc, ulsc;
204 
205 	if ((hif = a->altq_disc) == NULL)
206 		return (EINVAL);
207 
208 	opts = &a->pq_u.hfsc_opts;
209 
210 	if (a->parent_qid == HFSC_NULLCLASS_HANDLE && hif->hif_rootclass == NULL)
211 		parent = NULL;
212 	else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL)
213 		return (EINVAL);
214 
215 	if (a->qid == 0)
216 		return (EINVAL);
217 
218 	if (clh_to_clp(hif, a->qid) != NULL)
219 		return (EBUSY);
220 
221 	rtsc.m1 = opts->rtsc_m1;
222 	rtsc.d  = opts->rtsc_d;
223 	rtsc.m2 = opts->rtsc_m2;
224 	lssc.m1 = opts->lssc_m1;
225 	lssc.d  = opts->lssc_d;
226 	lssc.m2 = opts->lssc_m2;
227 	ulsc.m1 = opts->ulsc_m1;
228 	ulsc.d  = opts->ulsc_d;
229 	ulsc.m2 = opts->ulsc_m2;
230 
231 	cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc, parent, a->qlimit,
232 			       opts->flags, a->qid);
233 	if (cl == NULL)
234 		return (ENOMEM);
235 
236 	return (0);
237 }
238 
239 int
240 hfsc_remove_queue(struct pf_altq *a)
241 {
242 	struct hfsc_if *hif;
243 	struct hfsc_class *cl;
244 
245 	if ((hif = a->altq_disc) == NULL)
246 		return (EINVAL);
247 
248 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
249 		return (EINVAL);
250 
251 	return (hfsc_class_destroy(cl));
252 }
253 
254 int
255 hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
256 {
257 	struct hfsc_if *hif;
258 	struct hfsc_class *cl;
259 	struct hfsc_classstats stats;
260 	int error = 0;
261 
262 	if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL)
263 		return (EBADF);
264 
265 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
266 		return (EINVAL);
267 
268 	if (*nbytes < sizeof(stats))
269 		return (EINVAL);
270 
271 	get_class_stats(&stats, cl);
272 
273 	if ((error = copyout((caddr_t)&stats, ubuf, sizeof(stats))) != 0)
274 		return (error);
275 	*nbytes = sizeof(stats);
276 	return (0);
277 }
278 
279 /*
280  * bring the interface back to the initial state by discarding
281  * all the filters and classes except the root class.
282  */
283 static int
284 hfsc_clear_interface(struct hfsc_if *hif)
285 {
286 	struct hfsc_class *cl;
287 
288 	if (hif->hif_rootclass == NULL)
289 		return (0);
290 
291 
292 	/* clear out the classes */
293 	while ((cl = hif->hif_rootclass->cl_children) != NULL) {
294 		/*
295 		 * remove the first leaf class found in the hierarchy
296 		 * then start over
297 		 */
298 		for (; cl != NULL; cl = hfsc_nextclass(cl)) {
299 			if (!is_a_parent_class(cl)) {
300 				hfsc_class_destroy(cl);
301 				break;
302 			}
303 		}
304 	}
305 
306 	return (0);
307 }
308 
309 static int
310 hfsc_request(struct ifaltq *ifq, int req, void *arg)
311 {
312 	struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc;
313 
314 	crit_enter();
315 	switch (req) {
316 	case ALTRQ_PURGE:
317 		hfsc_purge(hif);
318 		break;
319 	}
320 	crit_exit();
321 	return (0);
322 }
323 
324 /* discard all the queued packets on the interface */
325 static void
326 hfsc_purge(struct hfsc_if *hif)
327 {
328 	struct hfsc_class *cl;
329 
330 	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl)) {
331 		if (!qempty(cl->cl_q))
332 			hfsc_purgeq(cl);
333 	}
334 	if (ifq_is_enabled(hif->hif_ifq))
335 		hif->hif_ifq->ifq_len = 0;
336 }
337 
338 struct hfsc_class *
339 hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc,
340 		  struct service_curve *fsc, struct service_curve *usc,
341 		  struct hfsc_class *parent, int qlimit, int flags, int qid)
342 {
343 	struct hfsc_class *cl, *p;
344 	int i;
345 
346 	if (hif->hif_classes >= HFSC_MAX_CLASSES)
347 		return (NULL);
348 
349 #ifndef ALTQ_RED
350 	if (flags & HFCF_RED) {
351 #ifdef ALTQ_DEBUG
352 		printf("hfsc_class_create: RED not configured for HFSC!\n");
353 #endif
354 		return (NULL);
355 	}
356 #endif
357 
358 	cl = malloc(sizeof(*cl), M_ALTQ, M_WAITOK | M_ZERO);
359 	cl->cl_q = malloc(sizeof(*cl->cl_q), M_ALTQ, M_WAITOK | M_ZERO);
360 	cl->cl_actc = actlist_alloc();
361 
362 	if (qlimit == 0)
363 		qlimit = 50;  /* use default */
364 	qlimit(cl->cl_q) = qlimit;
365 	qtype(cl->cl_q) = Q_DROPTAIL;
366 	qlen(cl->cl_q) = 0;
367 	cl->cl_flags = flags;
368 #ifdef ALTQ_RED
369 	if (flags & (HFCF_RED|HFCF_RIO)) {
370 		int red_flags, red_pkttime;
371 		u_int m2;
372 
373 		m2 = 0;
374 		if (rsc != NULL && rsc->m2 > m2)
375 			m2 = rsc->m2;
376 		if (fsc != NULL && fsc->m2 > m2)
377 			m2 = fsc->m2;
378 		if (usc != NULL && usc->m2 > m2)
379 			m2 = usc->m2;
380 
381 		red_flags = 0;
382 		if (flags & HFCF_ECN)
383 			red_flags |= REDF_ECN;
384 #ifdef ALTQ_RIO
385 		if (flags & HFCF_CLEARDSCP)
386 			red_flags |= RIOF_CLEARDSCP;
387 #endif
388 		if (m2 < 8)
389 			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
390 		else
391 			red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu
392 				* 1000 * 1000 * 1000 / (m2 / 8);
393 		if (flags & HFCF_RED) {
394 			cl->cl_red = red_alloc(0, 0,
395 			    qlimit(cl->cl_q) * 10/100,
396 			    qlimit(cl->cl_q) * 30/100,
397 			    red_flags, red_pkttime);
398 			if (cl->cl_red != NULL)
399 				qtype(cl->cl_q) = Q_RED;
400 		}
401 #ifdef ALTQ_RIO
402 		else {
403 			cl->cl_red = (red_t *)rio_alloc(0, NULL,
404 			    red_flags, red_pkttime);
405 			if (cl->cl_red != NULL)
406 				qtype(cl->cl_q) = Q_RIO;
407 		}
408 #endif
409 	}
410 #endif /* ALTQ_RED */
411 
412 	if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
413 		cl->cl_rsc = malloc(sizeof(*cl->cl_rsc), M_ALTQ, M_WAITOK);
414 		sc2isc(rsc, cl->cl_rsc);
415 		rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0);
416 		rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0);
417 	}
418 	if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) {
419 		cl->cl_fsc = malloc(sizeof(*cl->cl_fsc), M_ALTQ, M_WAITOK);
420 		if (cl->cl_fsc == NULL)
421 			goto err_ret;
422 		sc2isc(fsc, cl->cl_fsc);
423 		rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0);
424 	}
425 	if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) {
426 		cl->cl_usc = malloc(sizeof(*cl->cl_usc), M_ALTQ, M_WAITOK);
427 		if (cl->cl_usc == NULL)
428 			goto err_ret;
429 		sc2isc(usc, cl->cl_usc);
430 		rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0);
431 	}
432 
433 	cl->cl_id = hif->hif_classid++;
434 	cl->cl_handle = qid;
435 	cl->cl_hif = hif;
436 	cl->cl_parent = parent;
437 
438 	crit_enter();
439 	hif->hif_classes++;
440 
441 	/*
442 	 * find a free slot in the class table.  if the slot matching
443 	 * the lower bits of qid is free, use this slot.  otherwise,
444 	 * use the first free slot.
445 	 */
446 	i = qid % HFSC_MAX_CLASSES;
447 	if (hif->hif_class_tbl[i] == NULL)
448 		hif->hif_class_tbl[i] = cl;
449 	else {
450 		for (i = 0; i < HFSC_MAX_CLASSES; i++) {
451 			if (hif->hif_class_tbl[i] == NULL) {
452 				hif->hif_class_tbl[i] = cl;
453 				break;
454 			}
455 		}
456 		if (i == HFSC_MAX_CLASSES) {
457 			crit_exit();
458 			goto err_ret;
459 		}
460 	}
461 
462 	if (flags & HFCF_DEFAULTCLASS)
463 		hif->hif_defaultclass = cl;
464 
465 	if (parent == NULL) {
466 		/* this is root class */
467 		hif->hif_rootclass = cl;
468 	} else if (parent->cl_children == NULL) {
469 		/* add this class to the children list of the parent */
470 		parent->cl_children = cl;
471 	} else {
472 		p = parent->cl_children;
473 		while (p->cl_siblings != NULL)
474 			p = p->cl_siblings;
475 		p->cl_siblings = cl;
476 	}
477 	crit_exit();
478 
479 	return (cl);
480 
481  err_ret:
482 	if (cl->cl_actc != NULL)
483 		actlist_destroy(cl->cl_actc);
484 	if (cl->cl_red != NULL) {
485 #ifdef ALTQ_RIO
486 		if (q_is_rio(cl->cl_q))
487 			rio_destroy((rio_t *)cl->cl_red);
488 #endif
489 #ifdef ALTQ_RED
490 		if (q_is_red(cl->cl_q))
491 			red_destroy(cl->cl_red);
492 #endif
493 	}
494 	if (cl->cl_fsc != NULL)
495 		free(cl->cl_fsc, M_ALTQ);
496 	if (cl->cl_rsc != NULL)
497 		free(cl->cl_rsc, M_ALTQ);
498 	if (cl->cl_usc != NULL)
499 		free(cl->cl_usc, M_ALTQ);
500 	if (cl->cl_q != NULL)
501 		free(cl->cl_q, M_ALTQ);
502 	free(cl, M_ALTQ);
503 	return (NULL);
504 }
505 
506 static int
507 hfsc_class_destroy(struct hfsc_class *cl)
508 {
509 	int i;
510 
511 	if (cl == NULL)
512 		return (0);
513 
514 	if (is_a_parent_class(cl))
515 		return (EBUSY);
516 
517 	crit_enter();
518 
519 	if (!qempty(cl->cl_q))
520 		hfsc_purgeq(cl);
521 
522 	if (cl->cl_parent == NULL) {
523 		/* this is root class */
524 	} else {
525 		struct hfsc_class *p = cl->cl_parent->cl_children;
526 
527 		if (p == cl) {
528 			cl->cl_parent->cl_children = cl->cl_siblings;
529 		} else {
530 			do {
531 				if (p->cl_siblings == cl) {
532 					p->cl_siblings = cl->cl_siblings;
533 					break;
534 				}
535 			} while ((p = p->cl_siblings) != NULL);
536 		}
537 		KKASSERT(p != NULL);
538 	}
539 
540 	for (i = 0; i < HFSC_MAX_CLASSES; i++) {
541 		if (cl->cl_hif->hif_class_tbl[i] == cl) {
542 			cl->cl_hif->hif_class_tbl[i] = NULL;
543 			break;
544 		}
545 	}
546 
547 	cl->cl_hif->hif_classes--;
548 	crit_exit();
549 
550 	actlist_destroy(cl->cl_actc);
551 
552 	if (cl->cl_red != NULL) {
553 #ifdef ALTQ_RIO
554 		if (q_is_rio(cl->cl_q))
555 			rio_destroy((rio_t *)cl->cl_red);
556 #endif
557 #ifdef ALTQ_RED
558 		if (q_is_red(cl->cl_q))
559 			red_destroy(cl->cl_red);
560 #endif
561 	}
562 
563 	if (cl == cl->cl_hif->hif_rootclass)
564 		cl->cl_hif->hif_rootclass = NULL;
565 	if (cl == cl->cl_hif->hif_defaultclass)
566 		cl->cl_hif->hif_defaultclass = NULL;
567 
568 	if (cl->cl_usc != NULL)
569 		free(cl->cl_usc, M_ALTQ);
570 	if (cl->cl_fsc != NULL)
571 		free(cl->cl_fsc, M_ALTQ);
572 	if (cl->cl_rsc != NULL)
573 		free(cl->cl_rsc, M_ALTQ);
574 	free(cl->cl_q, M_ALTQ);
575 	free(cl, M_ALTQ);
576 
577 	return (0);
578 }
579 
580 /*
581  * hfsc_nextclass returns the next class in the tree.
582  *   usage:
583  *	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
584  *		do_something;
585  */
586 static struct hfsc_class *
587 hfsc_nextclass(struct hfsc_class *cl)
588 {
589 	if (cl->cl_children != NULL) {
590 		cl = cl->cl_children;
591 	} else if (cl->cl_siblings != NULL) {
592 		cl = cl->cl_siblings;
593 	} else {
594 		while ((cl = cl->cl_parent) != NULL) {
595 			if (cl->cl_siblings != NULL) {
596 				cl = cl->cl_siblings;
597 				break;
598 			}
599 		}
600 	}
601 
602 	return (cl);
603 }
604 
605 /*
606  * hfsc_enqueue is an enqueue function to be registered to
607  * (*altq_enqueue) in struct ifaltq.
608  */
609 static int
610 hfsc_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr)
611 {
612 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
613 	struct hfsc_class *cl;
614 	int len;
615 
616 	/* grab class set by classifier */
617 	if ((m->m_flags & M_PKTHDR) == 0) {
618 		/* should not happen */
619 		if_printf(ifq->altq_ifp, "altq: packet does not have pkthdr\n");
620 		m_freem(m);
621 		return (ENOBUFS);
622 	}
623 	crit_enter();
624 	if (m->m_pkthdr.fw_flags & ALTQ_MBUF_TAGGED)
625 		cl = clh_to_clp(hif, m->m_pkthdr.altq_qid);
626 	else
627 		cl = NULL;
628 	if (cl == NULL || is_a_parent_class(cl)) {
629 		cl = hif->hif_defaultclass;
630 		if (cl == NULL) {
631 			m_freem(m);
632 			crit_exit();
633 			return (ENOBUFS);
634 		}
635 	}
636 	cl->cl_pktattr = NULL;
637 	len = m_pktlen(m);
638 	if (hfsc_addq(cl, m) != 0) {
639 		/* drop occurred.  mbuf was freed in hfsc_addq. */
640 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len);
641 		crit_exit();
642 		return (ENOBUFS);
643 	}
644 	ifq->ifq_len++;
645 	cl->cl_hif->hif_packets++;
646 
647 	/* successfully queued. */
648 	if (qlen(cl->cl_q) == 1)
649 		set_active(cl, m_pktlen(m));
650 	crit_exit();
651 	return (0);
652 }
653 
654 /*
655  * hfsc_dequeue is a dequeue function to be registered to
656  * (*altq_dequeue) in struct ifaltq.
657  *
658  * note: ALTDQ_POLL returns the next packet without removing the packet
659  *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
660  *	ALTDQ_REMOVE must return the same packet if called immediately
661  *	after ALTDQ_POLL.
662  */
663 static struct mbuf *
664 hfsc_dequeue(struct ifaltq *ifq, int op)
665 {
666 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
667 	struct hfsc_class *cl;
668 	struct mbuf *m;
669 	int len, next_len;
670 	int realtime = 0;
671 	uint64_t cur_time;
672 
673 	if (hif->hif_packets == 0) {
674 		/* no packet in the tree */
675 		return (NULL);
676 	}
677 
678 	crit_enter();
679 	cur_time = read_machclk();
680 
681 	if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) {
682 		cl = hif->hif_pollcache;
683 		hif->hif_pollcache = NULL;
684 		/* check if the class was scheduled by real-time criteria */
685 		if (cl->cl_rsc != NULL)
686 			realtime = (cl->cl_e <= cur_time);
687 	} else {
688 		/*
689 		 * if there are eligible classes, use real-time criteria.
690 		 * find the class with the minimum deadline among
691 		 * the eligible classes.
692 		 */
693 		if ((cl = ellist_get_mindl(hif->hif_eligible, cur_time)) != NULL) {
694 			realtime = 1;
695 		} else {
696 #ifdef ALTQ_DEBUG
697 			int fits = 0;
698 #endif
699 			/*
700 			 * use link-sharing criteria
701 			 * get the class with the minimum vt in the hierarchy
702 			 */
703 			cl = hif->hif_rootclass;
704 			while (is_a_parent_class(cl)) {
705 
706 				cl = actlist_firstfit(cl, cur_time);
707 				if (cl == NULL) {
708 #ifdef ALTQ_DEBUG
709 					if (fits > 0)
710 						printf("%d fit but none found\n",fits);
711 #endif
712 					m = NULL;
713 					goto done;
714 				}
715 				/*
716 				 * update parent's cl_cvtmin.
717 				 * don't update if the new vt is smaller.
718 				 */
719 				if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
720 					cl->cl_parent->cl_cvtmin = cl->cl_vt;
721 #ifdef ALTQ_DEBUG
722 				fits++;
723 #endif
724 			}
725 		}
726 
727 		if (op == ALTDQ_POLL) {
728 			hif->hif_pollcache = cl;
729 			m = hfsc_pollq(cl);
730 			goto done;
731 		}
732 	}
733 
734 	m = hfsc_getq(cl);
735 	if (m == NULL)
736 		panic("hfsc_dequeue:");
737 	len = m_pktlen(m);
738 	cl->cl_hif->hif_packets--;
739 	ifq->ifq_len--;
740 	PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len);
741 
742 	update_vf(cl, len, cur_time);
743 	if (realtime)
744 		cl->cl_cumul += len;
745 
746 	if (!qempty(cl->cl_q)) {
747 		if (cl->cl_rsc != NULL) {
748 			/* update ed */
749 			next_len = m_pktlen(qhead(cl->cl_q));
750 
751 			if (realtime)
752 				update_ed(cl, next_len);
753 			else
754 				update_d(cl, next_len);
755 		}
756 	} else {
757 		/* the class becomes passive */
758 		set_passive(cl);
759 	}
760 done:
761 	crit_exit();
762 	return (m);
763 }
764 
765 static int
766 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
767 {
768 
769 #ifdef ALTQ_RIO
770 	if (q_is_rio(cl->cl_q))
771 		return rio_addq((rio_t *)cl->cl_red, cl->cl_q,
772 				m, cl->cl_pktattr);
773 #endif
774 #ifdef ALTQ_RED
775 	if (q_is_red(cl->cl_q))
776 		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
777 #endif
778 	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
779 		m_freem(m);
780 		return (-1);
781 	}
782 
783 	if (cl->cl_flags & HFCF_CLEARDSCP)
784 		write_dsfield(m, cl->cl_pktattr, 0);
785 
786 	_addq(cl->cl_q, m);
787 
788 	return (0);
789 }
790 
791 static struct mbuf *
792 hfsc_getq(struct hfsc_class *cl)
793 {
794 #ifdef ALTQ_RIO
795 	if (q_is_rio(cl->cl_q))
796 		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
797 #endif
798 #ifdef ALTQ_RED
799 	if (q_is_red(cl->cl_q))
800 		return red_getq(cl->cl_red, cl->cl_q);
801 #endif
802 	return _getq(cl->cl_q);
803 }
804 
805 static struct mbuf *
806 hfsc_pollq(struct hfsc_class *cl)
807 {
808 	return qhead(cl->cl_q);
809 }
810 
811 static void
812 hfsc_purgeq(struct hfsc_class *cl)
813 {
814 	struct mbuf *m;
815 
816 	if (qempty(cl->cl_q))
817 		return;
818 
819 	while ((m = _getq(cl->cl_q)) != NULL) {
820 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m));
821 		m_freem(m);
822 		cl->cl_hif->hif_packets--;
823 		cl->cl_hif->hif_ifq->ifq_len--;
824 	}
825 	KKASSERT(qlen(cl->cl_q) == 0);
826 
827 	update_vf(cl, 0, 0);	/* remove cl from the actlist */
828 	set_passive(cl);
829 }
830 
831 static void
832 set_active(struct hfsc_class *cl, int len)
833 {
834 	if (cl->cl_rsc != NULL)
835 		init_ed(cl, len);
836 	if (cl->cl_fsc != NULL)
837 		init_vf(cl, len);
838 
839 	cl->cl_stats.period++;
840 }
841 
842 static void
843 set_passive(struct hfsc_class *cl)
844 {
845 	if (cl->cl_rsc != NULL)
846 		ellist_remove(cl);
847 
848 	/*
849 	 * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
850 	 * needs to be called explicitly to remove a class from actlist
851 	 */
852 }
853 
854 static void
855 init_ed(struct hfsc_class *cl, int next_len)
856 {
857 	uint64_t cur_time;
858 
859 	cur_time = read_machclk();
860 
861 	/* update the deadline curve */
862 	rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul);
863 
864 	/*
865 	 * update the eligible curve.
866 	 * for concave, it is equal to the deadline curve.
867 	 * for convex, it is a linear curve with slope m2.
868 	 */
869 	cl->cl_eligible = cl->cl_deadline;
870 	if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) {
871 		cl->cl_eligible.dx = 0;
872 		cl->cl_eligible.dy = 0;
873 	}
874 
875 	/* compute e and d */
876 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
877 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
878 
879 	ellist_insert(cl);
880 }
881 
882 static void
883 update_ed(struct hfsc_class *cl, int next_len)
884 {
885 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
886 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
887 
888 	ellist_update(cl);
889 }
890 
891 static void
892 update_d(struct hfsc_class *cl, int next_len)
893 {
894 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
895 }
896 
897 static void
898 init_vf(struct hfsc_class *cl, int len)
899 {
900 	struct hfsc_class *max_cl, *p;
901 	uint64_t vt, f, cur_time;
902 	int go_active;
903 
904 	cur_time = 0;
905 	go_active = 1;
906 	for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) {
907 		if (go_active && cl->cl_nactive++ == 0)
908 			go_active = 1;
909 		else
910 			go_active = 0;
911 
912 		if (go_active) {
913 			max_cl = actlist_last(cl->cl_parent->cl_actc);
914 			if (max_cl != NULL) {
915 				/*
916 				 * set vt to the average of the min and max
917 				 * classes.  if the parent's period didn't
918 				 * change, don't decrease vt of the class.
919 				 */
920 				vt = max_cl->cl_vt;
921 				if (cl->cl_parent->cl_cvtmin != 0)
922 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
923 
924 				if (cl->cl_parent->cl_vtperiod !=
925 				    cl->cl_parentperiod || vt > cl->cl_vt)
926 					cl->cl_vt = vt;
927 			} else {
928 				/*
929 				 * first child for a new parent backlog period.
930 				 * add parent's cvtmax to vtoff of children
931 				 * to make a new vt (vtoff + vt) larger than
932 				 * the vt in the last period for all children.
933 				 */
934 				vt = cl->cl_parent->cl_cvtmax;
935 				for (p = cl->cl_parent->cl_children; p != NULL;
936 				     p = p->cl_siblings)
937 					p->cl_vtoff += vt;
938 				cl->cl_vt = 0;
939 				cl->cl_parent->cl_cvtmax = 0;
940 				cl->cl_parent->cl_cvtmin = 0;
941 			}
942 			cl->cl_initvt = cl->cl_vt;
943 
944 			/* update the virtual curve */
945 			vt = cl->cl_vt + cl->cl_vtoff;
946 			rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total);
947 			if (cl->cl_virtual.x == vt) {
948 				cl->cl_virtual.x -= cl->cl_vtoff;
949 				cl->cl_vtoff = 0;
950 			}
951 			cl->cl_vtadj = 0;
952 
953 			cl->cl_vtperiod++;  /* increment vt period */
954 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
955 			if (cl->cl_parent->cl_nactive == 0)
956 				cl->cl_parentperiod++;
957 			cl->cl_f = 0;
958 
959 			actlist_insert(cl);
960 
961 			if (cl->cl_usc != NULL) {
962 				/* class has upper limit curve */
963 				if (cur_time == 0)
964 					cur_time = read_machclk();
965 
966 				/* update the ulimit curve */
967 				rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time,
968 				    cl->cl_total);
969 				/* compute myf */
970 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
971 				    cl->cl_total);
972 				cl->cl_myfadj = 0;
973 			}
974 		}
975 
976 		if (cl->cl_myf > cl->cl_cfmin)
977 			f = cl->cl_myf;
978 		else
979 			f = cl->cl_cfmin;
980 		if (f != cl->cl_f) {
981 			cl->cl_f = f;
982 			update_cfmin(cl->cl_parent);
983 		}
984 	}
985 }
986 
987 static void
988 update_vf(struct hfsc_class *cl, int len, uint64_t cur_time)
989 {
990 	uint64_t f, myf_bound, delta;
991 	int go_passive;
992 
993 	go_passive = qempty(cl->cl_q);
994 
995 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
996 		cl->cl_total += len;
997 
998 		if (cl->cl_fsc == NULL || cl->cl_nactive == 0)
999 			continue;
1000 
1001 		if (go_passive && --cl->cl_nactive == 0)
1002 			go_passive = 1;
1003 		else
1004 			go_passive = 0;
1005 
1006 		if (go_passive) {
1007 			/* no more active child, going passive */
1008 
1009 			/* update cvtmax of the parent class */
1010 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
1011 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
1012 
1013 			/* remove this class from the vt list */
1014 			actlist_remove(cl);
1015 
1016 			update_cfmin(cl->cl_parent);
1017 
1018 			continue;
1019 		}
1020 
1021 		/*
1022 		 * update vt and f
1023 		 */
1024 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
1025 		    - cl->cl_vtoff + cl->cl_vtadj;
1026 
1027 		/*
1028 		 * if vt of the class is smaller than cvtmin,
1029 		 * the class was skipped in the past due to non-fit.
1030 		 * if so, we need to adjust vtadj.
1031 		 */
1032 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
1033 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
1034 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
1035 		}
1036 
1037 		/* update the vt list */
1038 		actlist_update(cl);
1039 
1040 		if (cl->cl_usc != NULL) {
1041 			cl->cl_myf = cl->cl_myfadj
1042 			    + rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
1043 
1044 			/*
1045 			 * if myf lags behind by more than one clock tick
1046 			 * from the current time, adjust myfadj to prevent
1047 			 * a rate-limited class from going greedy.
1048 			 * in a steady state under rate-limiting, myf
1049 			 * fluctuates within one clock tick.
1050 			 */
1051 			myf_bound = cur_time - machclk_per_tick;
1052 			if (cl->cl_myf < myf_bound) {
1053 				delta = cur_time - cl->cl_myf;
1054 				cl->cl_myfadj += delta;
1055 				cl->cl_myf += delta;
1056 			}
1057 		}
1058 
1059 		/* cl_f is max(cl_myf, cl_cfmin) */
1060 		if (cl->cl_myf > cl->cl_cfmin)
1061 			f = cl->cl_myf;
1062 		else
1063 			f = cl->cl_cfmin;
1064 		if (f != cl->cl_f) {
1065 			cl->cl_f = f;
1066 			update_cfmin(cl->cl_parent);
1067 		}
1068 	}
1069 }
1070 
1071 static void
1072 update_cfmin(struct hfsc_class *cl)
1073 {
1074 	struct hfsc_class *p;
1075 	uint64_t cfmin;
1076 
1077 	if (TAILQ_EMPTY(cl->cl_actc)) {
1078 		cl->cl_cfmin = 0;
1079 		return;
1080 	}
1081 	cfmin = HT_INFINITY;
1082 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1083 		if (p->cl_f == 0) {
1084 			cl->cl_cfmin = 0;
1085 			return;
1086 		}
1087 		if (p->cl_f < cfmin)
1088 			cfmin = p->cl_f;
1089 	}
1090 	cl->cl_cfmin = cfmin;
1091 }
1092 
1093 /*
1094  * TAILQ based ellist and actlist implementation
1095  * (ion wanted to make a calendar queue based implementation)
1096  */
1097 /*
1098  * eligible list holds backlogged classes being sorted by their eligible times.
1099  * there is one eligible list per interface.
1100  */
1101 
1102 static ellist_t *
1103 ellist_alloc(void)
1104 {
1105 	ellist_t *head;
1106 
1107 	head = malloc(sizeof(ellist_t *), M_ALTQ, M_WAITOK);
1108 	TAILQ_INIT(head);
1109 	return (head);
1110 }
1111 
1112 static void
1113 ellist_destroy(ellist_t *head)
1114 {
1115 	free(head, M_ALTQ);
1116 }
1117 
1118 static void
1119 ellist_insert(struct hfsc_class *cl)
1120 {
1121 	struct hfsc_if *hif = cl->cl_hif;
1122 	struct hfsc_class *p;
1123 
1124 	/* check the last entry first */
1125 	if ((p = TAILQ_LAST(hif->hif_eligible, _eligible)) == NULL ||
1126 	    p->cl_e <= cl->cl_e) {
1127 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1128 		return;
1129 	}
1130 
1131 	TAILQ_FOREACH(p, hif->hif_eligible, cl_ellist) {
1132 		if (cl->cl_e < p->cl_e) {
1133 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1134 			return;
1135 		}
1136 	}
1137 	KKASSERT(0); /* should not reach here */
1138 }
1139 
1140 static void
1141 ellist_remove(struct hfsc_class *cl)
1142 {
1143 	struct hfsc_if *hif = cl->cl_hif;
1144 
1145 	TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1146 }
1147 
1148 static void
1149 ellist_update(struct hfsc_class *cl)
1150 {
1151 	struct hfsc_if *hif = cl->cl_hif;
1152 	struct hfsc_class *p, *last;
1153 
1154 	/*
1155 	 * the eligible time of a class increases monotonically.
1156 	 * if the next entry has a larger eligible time, nothing to do.
1157 	 */
1158 	p = TAILQ_NEXT(cl, cl_ellist);
1159 	if (p == NULL || cl->cl_e <= p->cl_e)
1160 		return;
1161 
1162 	/* check the last entry */
1163 	last = TAILQ_LAST(hif->hif_eligible, _eligible);
1164 	KKASSERT(last != NULL);
1165 	if (last->cl_e <= cl->cl_e) {
1166 		TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1167 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1168 		return;
1169 	}
1170 
1171 	/*
1172 	 * the new position must be between the next entry
1173 	 * and the last entry
1174 	 */
1175 	while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) {
1176 		if (cl->cl_e < p->cl_e) {
1177 			TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1178 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1179 			return;
1180 		}
1181 	}
1182 	KKASSERT(0); /* should not reach here */
1183 }
1184 
1185 /* find the class with the minimum deadline among the eligible classes */
1186 struct hfsc_class *
1187 ellist_get_mindl(ellist_t *head, uint64_t cur_time)
1188 {
1189 	struct hfsc_class *p, *cl = NULL;
1190 
1191 	TAILQ_FOREACH(p, head, cl_ellist) {
1192 		if (p->cl_e > cur_time)
1193 			break;
1194 		if (cl == NULL || p->cl_d < cl->cl_d)
1195 			cl = p;
1196 	}
1197 	return (cl);
1198 }
1199 
1200 /*
1201  * active children list holds backlogged child classes being sorted
1202  * by their virtual time.
1203  * each intermediate class has one active children list.
1204  */
1205 static actlist_t *
1206 actlist_alloc(void)
1207 {
1208 	actlist_t *head;
1209 
1210 	head = malloc(sizeof(*head), M_ALTQ, M_WAITOK);
1211 	TAILQ_INIT(head);
1212 	return (head);
1213 }
1214 
1215 static void
1216 actlist_destroy(actlist_t *head)
1217 {
1218 	free(head, M_ALTQ);
1219 }
1220 static void
1221 actlist_insert(struct hfsc_class *cl)
1222 {
1223 	struct hfsc_class *p;
1224 
1225 	/* check the last entry first */
1226 	if ((p = TAILQ_LAST(cl->cl_parent->cl_actc, _active)) == NULL
1227 	    || p->cl_vt <= cl->cl_vt) {
1228 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1229 		return;
1230 	}
1231 
1232 	TAILQ_FOREACH(p, cl->cl_parent->cl_actc, cl_actlist) {
1233 		if (cl->cl_vt < p->cl_vt) {
1234 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1235 			return;
1236 		}
1237 	}
1238 	KKASSERT(0); /* should not reach here */
1239 }
1240 
1241 static void
1242 actlist_remove(struct hfsc_class *cl)
1243 {
1244 	TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1245 }
1246 
1247 static void
1248 actlist_update(struct hfsc_class *cl)
1249 {
1250 	struct hfsc_class *p, *last;
1251 
1252 	/*
1253 	 * the virtual time of a class increases monotonically during its
1254 	 * backlogged period.
1255 	 * if the next entry has a larger virtual time, nothing to do.
1256 	 */
1257 	p = TAILQ_NEXT(cl, cl_actlist);
1258 	if (p == NULL || cl->cl_vt < p->cl_vt)
1259 		return;
1260 
1261 	/* check the last entry */
1262 	last = TAILQ_LAST(cl->cl_parent->cl_actc, _active);
1263 	KKASSERT(last != NULL);
1264 	if (last->cl_vt <= cl->cl_vt) {
1265 		TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1266 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1267 		return;
1268 	}
1269 
1270 	/*
1271 	 * the new position must be between the next entry
1272 	 * and the last entry
1273 	 */
1274 	while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) {
1275 		if (cl->cl_vt < p->cl_vt) {
1276 			TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1277 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1278 			return;
1279 		}
1280 	}
1281 	KKASSERT(0); /* should not reach here */
1282 }
1283 
1284 static struct hfsc_class *
1285 actlist_firstfit(struct hfsc_class *cl, uint64_t cur_time)
1286 {
1287 	struct hfsc_class *p;
1288 
1289 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1290 		if (p->cl_f <= cur_time)
1291 			return (p);
1292 	}
1293 	return (NULL);
1294 }
1295 
1296 /*
1297  * service curve support functions
1298  *
1299  *  external service curve parameters
1300  *	m: bits/sec
1301  *	d: msec
1302  *  internal service curve parameters
1303  *	sm: (bytes/tsc_interval) << SM_SHIFT
1304  *	ism: (tsc_count/byte) << ISM_SHIFT
1305  *	dx: tsc_count
1306  *
1307  * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits.
1308  * we should be able to handle 100K-1Gbps linkspeed with 200Hz-1GHz CPU
1309  * speed.  SM_SHIFT and ISM_SHIFT are selected to have at least 3 effective
1310  * digits in decimal using the following table.
1311  *
1312  *  bits/sec    100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
1313  *  ----------+-------------------------------------------------------
1314  *  bytes/nsec  12.5e-6    125e-6     1250e-6    12500e-6   125000e-6
1315  *  sm(500MHz)  25.0e-6    250e-6     2500e-6    25000e-6   250000e-6
1316  *  sm(200MHz)  62.5e-6    625e-6     6250e-6    62500e-6   625000e-6
1317  *
1318  *  nsec/byte   80000      8000       800        80         8
1319  *  ism(500MHz) 40000      4000       400        40         4
1320  *  ism(200MHz) 16000      1600       160        16         1.6
1321  */
1322 #define	SM_SHIFT	24
1323 #define	ISM_SHIFT	10
1324 
1325 #define	SM_MASK		((1LL << SM_SHIFT) - 1)
1326 #define	ISM_MASK	((1LL << ISM_SHIFT) - 1)
1327 
1328 static __inline uint64_t
1329 seg_x2y(uint64_t x, uint64_t sm)
1330 {
1331 	uint64_t y;
1332 
1333 	/*
1334 	 * compute
1335 	 *	y = x * sm >> SM_SHIFT
1336 	 * but divide it for the upper and lower bits to avoid overflow
1337 	 */
1338 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
1339 	return (y);
1340 }
1341 
1342 static __inline uint64_t
1343 seg_y2x(uint64_t y, uint64_t ism)
1344 {
1345 	uint64_t x;
1346 
1347 	if (y == 0)
1348 		x = 0;
1349 	else if (ism == HT_INFINITY)
1350 		x = HT_INFINITY;
1351 	else
1352 		x = (y >> ISM_SHIFT) * ism + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
1353 
1354 	return (x);
1355 }
1356 
1357 static __inline uint64_t
1358 m2sm(u_int m)
1359 {
1360 	uint64_t sm;
1361 
1362 	sm = ((uint64_t)m << SM_SHIFT) / 8 / machclk_freq;
1363 	return (sm);
1364 }
1365 
1366 static __inline uint64_t
1367 m2ism(u_int m)
1368 {
1369 	uint64_t ism;
1370 
1371 	if (m == 0)
1372 		ism = HT_INFINITY;
1373 	else
1374 		ism = ((uint64_t)machclk_freq << ISM_SHIFT) * 8 / m;
1375 	return (ism);
1376 }
1377 
1378 static __inline uint64_t
1379 d2dx(u_int d)
1380 {
1381 	uint64_t dx;
1382 
1383 	dx = ((uint64_t)d * machclk_freq) / 1000;
1384 	return (dx);
1385 }
1386 
1387 static u_int
1388 sm2m(uint64_t sm)
1389 {
1390 	uint64_t m;
1391 
1392 	m = (sm * 8 * machclk_freq) >> SM_SHIFT;
1393 	return ((u_int)m);
1394 }
1395 
1396 static u_int
1397 dx2d(uint64_t dx)
1398 {
1399 	uint64_t d;
1400 
1401 	d = dx * 1000 / machclk_freq;
1402 	return ((u_int)d);
1403 }
1404 
1405 static void
1406 sc2isc(struct service_curve *sc, struct internal_sc *isc)
1407 {
1408 	isc->sm1 = m2sm(sc->m1);
1409 	isc->ism1 = m2ism(sc->m1);
1410 	isc->dx = d2dx(sc->d);
1411 	isc->dy = seg_x2y(isc->dx, isc->sm1);
1412 	isc->sm2 = m2sm(sc->m2);
1413 	isc->ism2 = m2ism(sc->m2);
1414 }
1415 
1416 /*
1417  * initialize the runtime service curve with the given internal
1418  * service curve starting at (x, y).
1419  */
1420 static void
1421 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1422 {
1423 	rtsc->x = x;
1424 	rtsc->y = y;
1425 	rtsc->sm1 = isc->sm1;
1426 	rtsc->ism1 = isc->ism1;
1427 	rtsc->dx = isc->dx;
1428 	rtsc->dy = isc->dy;
1429 	rtsc->sm2 = isc->sm2;
1430 	rtsc->ism2 = isc->ism2;
1431 }
1432 
1433 /*
1434  * calculate the y-projection of the runtime service curve by the
1435  * given x-projection value
1436  */
1437 static uint64_t
1438 rtsc_y2x(struct runtime_sc *rtsc, uint64_t y)
1439 {
1440 	uint64_t x;
1441 
1442 	if (y < rtsc->y) {
1443 		x = rtsc->x;
1444 	} else if (y <= rtsc->y + rtsc->dy) {
1445 		/* x belongs to the 1st segment */
1446 		if (rtsc->dy == 0)
1447 			x = rtsc->x + rtsc->dx;
1448 		else
1449 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
1450 	} else {
1451 		/* x belongs to the 2nd segment */
1452 		x = rtsc->x + rtsc->dx
1453 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
1454 	}
1455 	return (x);
1456 }
1457 
1458 static uint64_t
1459 rtsc_x2y(struct runtime_sc *rtsc, uint64_t x)
1460 {
1461 	uint64_t y;
1462 
1463 	if (x <= rtsc->x) {
1464 		y = rtsc->y;
1465 	} else if (x <= rtsc->x + rtsc->dx) {
1466 		/* y belongs to the 1st segment */
1467 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
1468 	} else
1469 		/* y belongs to the 2nd segment */
1470 		y = rtsc->y + rtsc->dy
1471 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
1472 	return (y);
1473 }
1474 
1475 /*
1476  * update the runtime service curve by taking the minimum of the current
1477  * runtime service curve and the service curve starting at (x, y).
1478  */
1479 static void
1480 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1481 {
1482 	uint64_t y1, y2, dx, dy;
1483 
1484 	if (isc->sm1 <= isc->sm2) {
1485 		/* service curve is convex */
1486 		y1 = rtsc_x2y(rtsc, x);
1487 		if (y1 < y)
1488 			/* the current rtsc is smaller */
1489 			return;
1490 		rtsc->x = x;
1491 		rtsc->y = y;
1492 		return;
1493 	}
1494 
1495 	/*
1496 	 * service curve is concave
1497 	 * compute the two y values of the current rtsc
1498 	 *	y1: at x
1499 	 *	y2: at (x + dx)
1500 	 */
1501 	y1 = rtsc_x2y(rtsc, x);
1502 	if (y1 <= y) {
1503 		/* rtsc is below isc, no change to rtsc */
1504 		return;
1505 	}
1506 
1507 	y2 = rtsc_x2y(rtsc, x + isc->dx);
1508 	if (y2 >= y + isc->dy) {
1509 		/* rtsc is above isc, replace rtsc by isc */
1510 		rtsc->x = x;
1511 		rtsc->y = y;
1512 		rtsc->dx = isc->dx;
1513 		rtsc->dy = isc->dy;
1514 		return;
1515 	}
1516 
1517 	/*
1518 	 * the two curves intersect
1519 	 * compute the offsets (dx, dy) using the reverse
1520 	 * function of seg_x2y()
1521 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
1522 	 */
1523 	dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2);
1524 	/*
1525 	 * check if (x, y1) belongs to the 1st segment of rtsc.
1526 	 * if so, add the offset.
1527 	 */
1528 	if (rtsc->x + rtsc->dx > x)
1529 		dx += rtsc->x + rtsc->dx - x;
1530 	dy = seg_x2y(dx, isc->sm1);
1531 
1532 	rtsc->x = x;
1533 	rtsc->y = y;
1534 	rtsc->dx = dx;
1535 	rtsc->dy = dy;
1536 }
1537 
1538 static void
1539 get_class_stats(struct hfsc_classstats *sp, struct hfsc_class *cl)
1540 {
1541 	sp->class_id = cl->cl_id;
1542 	sp->class_handle = cl->cl_handle;
1543 
1544 	if (cl->cl_rsc != NULL) {
1545 		sp->rsc.m1 = sm2m(cl->cl_rsc->sm1);
1546 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1547 		sp->rsc.m2 = sm2m(cl->cl_rsc->sm2);
1548 	} else {
1549 		sp->rsc.m1 = 0;
1550 		sp->rsc.d = 0;
1551 		sp->rsc.m2 = 0;
1552 	}
1553 	if (cl->cl_fsc != NULL) {
1554 		sp->fsc.m1 = sm2m(cl->cl_fsc->sm1);
1555 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1556 		sp->fsc.m2 = sm2m(cl->cl_fsc->sm2);
1557 	} else {
1558 		sp->fsc.m1 = 0;
1559 		sp->fsc.d = 0;
1560 		sp->fsc.m2 = 0;
1561 	}
1562 	if (cl->cl_usc != NULL) {
1563 		sp->usc.m1 = sm2m(cl->cl_usc->sm1);
1564 		sp->usc.d = dx2d(cl->cl_usc->dx);
1565 		sp->usc.m2 = sm2m(cl->cl_usc->sm2);
1566 	} else {
1567 		sp->usc.m1 = 0;
1568 		sp->usc.d = 0;
1569 		sp->usc.m2 = 0;
1570 	}
1571 
1572 	sp->total = cl->cl_total;
1573 	sp->cumul = cl->cl_cumul;
1574 
1575 	sp->d = cl->cl_d;
1576 	sp->e = cl->cl_e;
1577 	sp->vt = cl->cl_vt;
1578 	sp->f = cl->cl_f;
1579 
1580 	sp->initvt = cl->cl_initvt;
1581 	sp->vtperiod = cl->cl_vtperiod;
1582 	sp->parentperiod = cl->cl_parentperiod;
1583 	sp->nactive = cl->cl_nactive;
1584 	sp->vtoff = cl->cl_vtoff;
1585 	sp->cvtmax = cl->cl_cvtmax;
1586 	sp->myf = cl->cl_myf;
1587 	sp->cfmin = cl->cl_cfmin;
1588 	sp->cvtmin = cl->cl_cvtmin;
1589 	sp->myfadj = cl->cl_myfadj;
1590 	sp->vtadj = cl->cl_vtadj;
1591 
1592 	sp->cur_time = read_machclk();
1593 	sp->machclk_freq = machclk_freq;
1594 
1595 	sp->qlength = qlen(cl->cl_q);
1596 	sp->qlimit = qlimit(cl->cl_q);
1597 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1598 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1599 	sp->period = cl->cl_stats.period;
1600 
1601 	sp->qtype = qtype(cl->cl_q);
1602 #ifdef ALTQ_RED
1603 	if (q_is_red(cl->cl_q))
1604 		red_getstats(cl->cl_red, &sp->red[0]);
1605 #endif
1606 #ifdef ALTQ_RIO
1607 	if (q_is_rio(cl->cl_q))
1608 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1609 #endif
1610 }
1611 
1612 /* convert a class handle to the corresponding class pointer */
1613 static struct hfsc_class *
1614 clh_to_clp(struct hfsc_if *hif, uint32_t chandle)
1615 {
1616 	int i;
1617 	struct hfsc_class *cl;
1618 
1619 	if (chandle == 0)
1620 		return (NULL);
1621 	/*
1622 	 * first, try optimistically the slot matching the lower bits of
1623 	 * the handle.  if it fails, do the linear table search.
1624 	 */
1625 	i = chandle % HFSC_MAX_CLASSES;
1626 	if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle)
1627 		return (cl);
1628 	for (i = 0; i < HFSC_MAX_CLASSES; i++)
1629 		if ((cl = hif->hif_class_tbl[i]) != NULL &&
1630 		    cl->cl_handle == chandle)
1631 			return (cl);
1632 	return (NULL);
1633 }
1634 
1635 #endif /* ALTQ_HFSC */
1636