xref: /dragonfly/sys/net/altq/altq_hfsc.c (revision 3f5e28f4)
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 1.8 2006/12/22 23:44:55 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 *, struct mbuf *, 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 = kmalloc(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 	ifq_purge(&ifp->if_snd);
172 
173 	/* keep the state in pf_altq */
174 	a->altq_disc = hif;
175 
176 	return (0);
177 }
178 
179 int
180 hfsc_remove_altq(struct pf_altq *a)
181 {
182 	struct hfsc_if *hif;
183 
184 	if ((hif = a->altq_disc) == NULL)
185 		return (EINVAL);
186 	a->altq_disc = NULL;
187 
188 	hfsc_clear_interface(hif);
189 	hfsc_class_destroy(hif->hif_rootclass);
190 
191 	ellist_destroy(hif->hif_eligible);
192 
193 	kfree(hif, M_ALTQ);
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 *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 && hif->hif_rootclass == NULL)
212 		parent = NULL;
213 	else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL)
214 		return (EINVAL);
215 
216 	if (a->qid == 0)
217 		return (EINVAL);
218 
219 	if (clh_to_clp(hif, a->qid) != NULL)
220 		return (EBUSY);
221 
222 	rtsc.m1 = opts->rtsc_m1;
223 	rtsc.d  = opts->rtsc_d;
224 	rtsc.m2 = opts->rtsc_m2;
225 	lssc.m1 = opts->lssc_m1;
226 	lssc.d  = opts->lssc_d;
227 	lssc.m2 = opts->lssc_m2;
228 	ulsc.m1 = opts->ulsc_m1;
229 	ulsc.d  = opts->ulsc_d;
230 	ulsc.m2 = opts->ulsc_m2;
231 
232 	cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc, parent, a->qlimit,
233 			       opts->flags, a->qid);
234 	if (cl == NULL)
235 		return (ENOMEM);
236 
237 	return (0);
238 }
239 
240 int
241 hfsc_remove_queue(struct pf_altq *a)
242 {
243 	struct hfsc_if *hif;
244 	struct hfsc_class *cl;
245 
246 	if ((hif = a->altq_disc) == NULL)
247 		return (EINVAL);
248 
249 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
250 		return (EINVAL);
251 
252 	return (hfsc_class_destroy(cl));
253 }
254 
255 int
256 hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
257 {
258 	struct hfsc_if *hif;
259 	struct hfsc_class *cl;
260 	struct hfsc_classstats stats;
261 	int error = 0;
262 
263 	if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL)
264 		return (EBADF);
265 
266 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
267 		return (EINVAL);
268 
269 	if (*nbytes < sizeof(stats))
270 		return (EINVAL);
271 
272 	get_class_stats(&stats, cl);
273 
274 	if ((error = copyout((caddr_t)&stats, ubuf, sizeof(stats))) != 0)
275 		return (error);
276 	*nbytes = sizeof(stats);
277 	return (0);
278 }
279 
280 /*
281  * bring the interface back to the initial state by discarding
282  * all the filters and classes except the root class.
283  */
284 static int
285 hfsc_clear_interface(struct hfsc_if *hif)
286 {
287 	struct hfsc_class *cl;
288 
289 	if (hif->hif_rootclass == NULL)
290 		return (0);
291 
292 
293 	/* clear out the classes */
294 	while ((cl = hif->hif_rootclass->cl_children) != NULL) {
295 		/*
296 		 * remove the first leaf class found in the hierarchy
297 		 * then start over
298 		 */
299 		for (; cl != NULL; cl = hfsc_nextclass(cl)) {
300 			if (!is_a_parent_class(cl)) {
301 				hfsc_class_destroy(cl);
302 				break;
303 			}
304 		}
305 	}
306 
307 	return (0);
308 }
309 
310 static int
311 hfsc_request(struct ifaltq *ifq, int req, void *arg)
312 {
313 	struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc;
314 
315 	crit_enter();
316 	switch (req) {
317 	case ALTRQ_PURGE:
318 		hfsc_purge(hif);
319 		break;
320 	}
321 	crit_exit();
322 	return (0);
323 }
324 
325 /* discard all the queued packets on the interface */
326 static void
327 hfsc_purge(struct hfsc_if *hif)
328 {
329 	struct hfsc_class *cl;
330 
331 	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl)) {
332 		if (!qempty(cl->cl_q))
333 			hfsc_purgeq(cl);
334 	}
335 	if (ifq_is_enabled(hif->hif_ifq))
336 		hif->hif_ifq->ifq_len = 0;
337 }
338 
339 struct hfsc_class *
340 hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc,
341 		  struct service_curve *fsc, struct service_curve *usc,
342 		  struct hfsc_class *parent, int qlimit, int flags, int qid)
343 {
344 	struct hfsc_class *cl, *p;
345 	int i;
346 
347 	if (hif->hif_classes >= HFSC_MAX_CLASSES)
348 		return (NULL);
349 
350 #ifndef ALTQ_RED
351 	if (flags & HFCF_RED) {
352 #ifdef ALTQ_DEBUG
353 		kprintf("hfsc_class_create: RED not configured for HFSC!\n");
354 #endif
355 		return (NULL);
356 	}
357 #endif
358 
359 	cl = kmalloc(sizeof(*cl), M_ALTQ, M_WAITOK | M_ZERO);
360 	cl->cl_q = kmalloc(sizeof(*cl->cl_q), M_ALTQ, M_WAITOK | M_ZERO);
361 	cl->cl_actc = actlist_alloc();
362 
363 	if (qlimit == 0)
364 		qlimit = 50;  /* use default */
365 	qlimit(cl->cl_q) = qlimit;
366 	qtype(cl->cl_q) = Q_DROPTAIL;
367 	qlen(cl->cl_q) = 0;
368 	cl->cl_flags = flags;
369 #ifdef ALTQ_RED
370 	if (flags & (HFCF_RED|HFCF_RIO)) {
371 		int red_flags, red_pkttime;
372 		u_int m2;
373 
374 		m2 = 0;
375 		if (rsc != NULL && rsc->m2 > m2)
376 			m2 = rsc->m2;
377 		if (fsc != NULL && fsc->m2 > m2)
378 			m2 = fsc->m2;
379 		if (usc != NULL && usc->m2 > m2)
380 			m2 = usc->m2;
381 
382 		red_flags = 0;
383 		if (flags & HFCF_ECN)
384 			red_flags |= REDF_ECN;
385 #ifdef ALTQ_RIO
386 		if (flags & HFCF_CLEARDSCP)
387 			red_flags |= RIOF_CLEARDSCP;
388 #endif
389 		if (m2 < 8)
390 			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
391 		else
392 			red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu
393 				* 1000 * 1000 * 1000 / (m2 / 8);
394 		if (flags & HFCF_RED) {
395 			cl->cl_red = red_alloc(0, 0,
396 			    qlimit(cl->cl_q) * 10/100,
397 			    qlimit(cl->cl_q) * 30/100,
398 			    red_flags, red_pkttime);
399 			if (cl->cl_red != NULL)
400 				qtype(cl->cl_q) = Q_RED;
401 		}
402 #ifdef ALTQ_RIO
403 		else {
404 			cl->cl_red = (red_t *)rio_alloc(0, NULL,
405 			    red_flags, red_pkttime);
406 			if (cl->cl_red != NULL)
407 				qtype(cl->cl_q) = Q_RIO;
408 		}
409 #endif
410 	}
411 #endif /* ALTQ_RED */
412 
413 	if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
414 		cl->cl_rsc = kmalloc(sizeof(*cl->cl_rsc), M_ALTQ, M_WAITOK);
415 		sc2isc(rsc, cl->cl_rsc);
416 		rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0);
417 		rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0);
418 	}
419 	if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) {
420 		cl->cl_fsc = kmalloc(sizeof(*cl->cl_fsc), M_ALTQ, M_WAITOK);
421 		if (cl->cl_fsc == NULL)
422 			goto err_ret;
423 		sc2isc(fsc, cl->cl_fsc);
424 		rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0);
425 	}
426 	if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) {
427 		cl->cl_usc = kmalloc(sizeof(*cl->cl_usc), M_ALTQ, M_WAITOK);
428 		if (cl->cl_usc == NULL)
429 			goto err_ret;
430 		sc2isc(usc, cl->cl_usc);
431 		rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0);
432 	}
433 
434 	cl->cl_id = hif->hif_classid++;
435 	cl->cl_handle = qid;
436 	cl->cl_hif = hif;
437 	cl->cl_parent = parent;
438 
439 	crit_enter();
440 	hif->hif_classes++;
441 
442 	/*
443 	 * find a free slot in the class table.  if the slot matching
444 	 * the lower bits of qid is free, use this slot.  otherwise,
445 	 * use the first free slot.
446 	 */
447 	i = qid % HFSC_MAX_CLASSES;
448 	if (hif->hif_class_tbl[i] == NULL)
449 		hif->hif_class_tbl[i] = cl;
450 	else {
451 		for (i = 0; i < HFSC_MAX_CLASSES; i++) {
452 			if (hif->hif_class_tbl[i] == NULL) {
453 				hif->hif_class_tbl[i] = cl;
454 				break;
455 			}
456 		}
457 		if (i == HFSC_MAX_CLASSES) {
458 			crit_exit();
459 			goto err_ret;
460 		}
461 	}
462 
463 	if (flags & HFCF_DEFAULTCLASS)
464 		hif->hif_defaultclass = cl;
465 
466 	if (parent == NULL) {
467 		/* this is root class */
468 		hif->hif_rootclass = cl;
469 	} else if (parent->cl_children == NULL) {
470 		/* add this class to the children list of the parent */
471 		parent->cl_children = cl;
472 	} else {
473 		p = parent->cl_children;
474 		while (p->cl_siblings != NULL)
475 			p = p->cl_siblings;
476 		p->cl_siblings = cl;
477 	}
478 	crit_exit();
479 
480 	return (cl);
481 
482  err_ret:
483 	if (cl->cl_actc != NULL)
484 		actlist_destroy(cl->cl_actc);
485 	if (cl->cl_red != NULL) {
486 #ifdef ALTQ_RIO
487 		if (q_is_rio(cl->cl_q))
488 			rio_destroy((rio_t *)cl->cl_red);
489 #endif
490 #ifdef ALTQ_RED
491 		if (q_is_red(cl->cl_q))
492 			red_destroy(cl->cl_red);
493 #endif
494 	}
495 	if (cl->cl_fsc != NULL)
496 		kfree(cl->cl_fsc, M_ALTQ);
497 	if (cl->cl_rsc != NULL)
498 		kfree(cl->cl_rsc, M_ALTQ);
499 	if (cl->cl_usc != NULL)
500 		kfree(cl->cl_usc, M_ALTQ);
501 	if (cl->cl_q != NULL)
502 		kfree(cl->cl_q, M_ALTQ);
503 	kfree(cl, M_ALTQ);
504 	return (NULL);
505 }
506 
507 static int
508 hfsc_class_destroy(struct hfsc_class *cl)
509 {
510 	int i;
511 
512 	if (cl == NULL)
513 		return (0);
514 
515 	if (is_a_parent_class(cl))
516 		return (EBUSY);
517 
518 	crit_enter();
519 
520 	if (!qempty(cl->cl_q))
521 		hfsc_purgeq(cl);
522 
523 	if (cl->cl_parent == NULL) {
524 		/* this is root class */
525 	} else {
526 		struct hfsc_class *p = cl->cl_parent->cl_children;
527 
528 		if (p == cl) {
529 			cl->cl_parent->cl_children = cl->cl_siblings;
530 		} else {
531 			do {
532 				if (p->cl_siblings == cl) {
533 					p->cl_siblings = cl->cl_siblings;
534 					break;
535 				}
536 			} while ((p = p->cl_siblings) != NULL);
537 		}
538 		KKASSERT(p != NULL);
539 	}
540 
541 	for (i = 0; i < HFSC_MAX_CLASSES; i++) {
542 		if (cl->cl_hif->hif_class_tbl[i] == cl) {
543 			cl->cl_hif->hif_class_tbl[i] = NULL;
544 			break;
545 		}
546 	}
547 
548 	cl->cl_hif->hif_classes--;
549 	crit_exit();
550 
551 	actlist_destroy(cl->cl_actc);
552 
553 	if (cl->cl_red != NULL) {
554 #ifdef ALTQ_RIO
555 		if (q_is_rio(cl->cl_q))
556 			rio_destroy((rio_t *)cl->cl_red);
557 #endif
558 #ifdef ALTQ_RED
559 		if (q_is_red(cl->cl_q))
560 			red_destroy(cl->cl_red);
561 #endif
562 	}
563 
564 	if (cl == cl->cl_hif->hif_rootclass)
565 		cl->cl_hif->hif_rootclass = NULL;
566 	if (cl == cl->cl_hif->hif_defaultclass)
567 		cl->cl_hif->hif_defaultclass = NULL;
568 
569 	if (cl->cl_usc != NULL)
570 		kfree(cl->cl_usc, M_ALTQ);
571 	if (cl->cl_fsc != NULL)
572 		kfree(cl->cl_fsc, M_ALTQ);
573 	if (cl->cl_rsc != NULL)
574 		kfree(cl->cl_rsc, M_ALTQ);
575 	kfree(cl->cl_q, M_ALTQ);
576 	kfree(cl, M_ALTQ);
577 
578 	return (0);
579 }
580 
581 /*
582  * hfsc_nextclass returns the next class in the tree.
583  *   usage:
584  *	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
585  *		do_something;
586  */
587 static struct hfsc_class *
588 hfsc_nextclass(struct hfsc_class *cl)
589 {
590 	if (cl->cl_children != NULL) {
591 		cl = cl->cl_children;
592 	} else if (cl->cl_siblings != NULL) {
593 		cl = cl->cl_siblings;
594 	} else {
595 		while ((cl = cl->cl_parent) != NULL) {
596 			if (cl->cl_siblings != NULL) {
597 				cl = cl->cl_siblings;
598 				break;
599 			}
600 		}
601 	}
602 
603 	return (cl);
604 }
605 
606 /*
607  * hfsc_enqueue is an enqueue function to be registered to
608  * (*altq_enqueue) in struct ifaltq.
609  */
610 static int
611 hfsc_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr)
612 {
613 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
614 	struct hfsc_class *cl;
615 	int len;
616 
617 	/* grab class set by classifier */
618 	if ((m->m_flags & M_PKTHDR) == 0) {
619 		/* should not happen */
620 		if_printf(ifq->altq_ifp, "altq: packet does not have pkthdr\n");
621 		m_freem(m);
622 		return (ENOBUFS);
623 	}
624 	crit_enter();
625 	if (m->m_pkthdr.fw_flags & ALTQ_MBUF_TAGGED)
626 		cl = clh_to_clp(hif, m->m_pkthdr.altq_qid);
627 	else
628 		cl = NULL;
629 	if (cl == NULL || is_a_parent_class(cl)) {
630 		cl = hif->hif_defaultclass;
631 		if (cl == NULL) {
632 			m_freem(m);
633 			crit_exit();
634 			return (ENOBUFS);
635 		}
636 	}
637 	cl->cl_pktattr = NULL;
638 	len = m_pktlen(m);
639 	if (hfsc_addq(cl, m) != 0) {
640 		/* drop occurred.  mbuf was freed in hfsc_addq. */
641 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len);
642 		crit_exit();
643 		return (ENOBUFS);
644 	}
645 	ifq->ifq_len++;
646 	cl->cl_hif->hif_packets++;
647 
648 	/* successfully queued. */
649 	if (qlen(cl->cl_q) == 1)
650 		set_active(cl, m_pktlen(m));
651 	crit_exit();
652 	return (0);
653 }
654 
655 /*
656  * hfsc_dequeue is a dequeue function to be registered to
657  * (*altq_dequeue) in struct ifaltq.
658  *
659  * note: ALTDQ_POLL returns the next packet without removing the packet
660  *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
661  *	ALTDQ_REMOVE must return the same packet if called immediately
662  *	after ALTDQ_POLL.
663  */
664 static struct mbuf *
665 hfsc_dequeue(struct ifaltq *ifq, struct mbuf *mpolled, int op)
666 {
667 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
668 	struct hfsc_class *cl;
669 	struct mbuf *m;
670 	int len, next_len;
671 	int realtime = 0;
672 	uint64_t cur_time;
673 
674 	if (hif->hif_packets == 0) {
675 		/* no packet in the tree */
676 		return (NULL);
677 	}
678 
679 	crit_enter();
680 	cur_time = read_machclk();
681 
682 	if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) {
683 		cl = hif->hif_pollcache;
684 		hif->hif_pollcache = NULL;
685 		/* check if the class was scheduled by real-time criteria */
686 		if (cl->cl_rsc != NULL)
687 			realtime = (cl->cl_e <= cur_time);
688 	} else {
689 		/*
690 		 * if there are eligible classes, use real-time criteria.
691 		 * find the class with the minimum deadline among
692 		 * the eligible classes.
693 		 */
694 		if ((cl = ellist_get_mindl(hif->hif_eligible, cur_time)) != NULL) {
695 			realtime = 1;
696 		} else {
697 #ifdef ALTQ_DEBUG
698 			int fits = 0;
699 #endif
700 			/*
701 			 * use link-sharing criteria
702 			 * get the class with the minimum vt in the hierarchy
703 			 */
704 			cl = hif->hif_rootclass;
705 			while (is_a_parent_class(cl)) {
706 
707 				cl = actlist_firstfit(cl, cur_time);
708 				if (cl == NULL) {
709 #ifdef ALTQ_DEBUG
710 					if (fits > 0)
711 						kprintf("%d fit but none found\n",fits);
712 #endif
713 					m = NULL;
714 					goto done;
715 				}
716 				/*
717 				 * update parent's cl_cvtmin.
718 				 * don't update if the new vt is smaller.
719 				 */
720 				if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
721 					cl->cl_parent->cl_cvtmin = cl->cl_vt;
722 #ifdef ALTQ_DEBUG
723 				fits++;
724 #endif
725 			}
726 		}
727 
728 		if (op == ALTDQ_POLL) {
729 			hif->hif_pollcache = cl;
730 			m = hfsc_pollq(cl);
731 			goto done;
732 		}
733 	}
734 
735 	m = hfsc_getq(cl);
736 	if (m == NULL)
737 		panic("hfsc_dequeue:");
738 	len = m_pktlen(m);
739 	cl->cl_hif->hif_packets--;
740 	ifq->ifq_len--;
741 	PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len);
742 
743 	update_vf(cl, len, cur_time);
744 	if (realtime)
745 		cl->cl_cumul += len;
746 
747 	if (!qempty(cl->cl_q)) {
748 		if (cl->cl_rsc != NULL) {
749 			/* update ed */
750 			next_len = m_pktlen(qhead(cl->cl_q));
751 
752 			if (realtime)
753 				update_ed(cl, next_len);
754 			else
755 				update_d(cl, next_len);
756 		}
757 	} else {
758 		/* the class becomes passive */
759 		set_passive(cl);
760 	}
761 done:
762 	crit_exit();
763 	KKASSERT(mpolled == NULL || m == mpolled);
764 	return (m);
765 }
766 
767 static int
768 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
769 {
770 
771 #ifdef ALTQ_RIO
772 	if (q_is_rio(cl->cl_q))
773 		return rio_addq((rio_t *)cl->cl_red, cl->cl_q,
774 				m, cl->cl_pktattr);
775 #endif
776 #ifdef ALTQ_RED
777 	if (q_is_red(cl->cl_q))
778 		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
779 #endif
780 	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
781 		m_freem(m);
782 		return (-1);
783 	}
784 
785 	if (cl->cl_flags & HFCF_CLEARDSCP)
786 		write_dsfield(m, cl->cl_pktattr, 0);
787 
788 	_addq(cl->cl_q, m);
789 
790 	return (0);
791 }
792 
793 static struct mbuf *
794 hfsc_getq(struct hfsc_class *cl)
795 {
796 #ifdef ALTQ_RIO
797 	if (q_is_rio(cl->cl_q))
798 		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
799 #endif
800 #ifdef ALTQ_RED
801 	if (q_is_red(cl->cl_q))
802 		return red_getq(cl->cl_red, cl->cl_q);
803 #endif
804 	return _getq(cl->cl_q);
805 }
806 
807 static struct mbuf *
808 hfsc_pollq(struct hfsc_class *cl)
809 {
810 	return qhead(cl->cl_q);
811 }
812 
813 static void
814 hfsc_purgeq(struct hfsc_class *cl)
815 {
816 	struct mbuf *m;
817 
818 	if (qempty(cl->cl_q))
819 		return;
820 
821 	while ((m = _getq(cl->cl_q)) != NULL) {
822 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m));
823 		m_freem(m);
824 		cl->cl_hif->hif_packets--;
825 		cl->cl_hif->hif_ifq->ifq_len--;
826 	}
827 	KKASSERT(qlen(cl->cl_q) == 0);
828 
829 	update_vf(cl, 0, 0);	/* remove cl from the actlist */
830 	set_passive(cl);
831 }
832 
833 static void
834 set_active(struct hfsc_class *cl, int len)
835 {
836 	if (cl->cl_rsc != NULL)
837 		init_ed(cl, len);
838 	if (cl->cl_fsc != NULL)
839 		init_vf(cl, len);
840 
841 	cl->cl_stats.period++;
842 }
843 
844 static void
845 set_passive(struct hfsc_class *cl)
846 {
847 	if (cl->cl_rsc != NULL)
848 		ellist_remove(cl);
849 
850 	/*
851 	 * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
852 	 * needs to be called explicitly to remove a class from actlist
853 	 */
854 }
855 
856 static void
857 init_ed(struct hfsc_class *cl, int next_len)
858 {
859 	uint64_t cur_time;
860 
861 	cur_time = read_machclk();
862 
863 	/* update the deadline curve */
864 	rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul);
865 
866 	/*
867 	 * update the eligible curve.
868 	 * for concave, it is equal to the deadline curve.
869 	 * for convex, it is a linear curve with slope m2.
870 	 */
871 	cl->cl_eligible = cl->cl_deadline;
872 	if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) {
873 		cl->cl_eligible.dx = 0;
874 		cl->cl_eligible.dy = 0;
875 	}
876 
877 	/* compute e and d */
878 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
879 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
880 
881 	ellist_insert(cl);
882 }
883 
884 static void
885 update_ed(struct hfsc_class *cl, int next_len)
886 {
887 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
888 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
889 
890 	ellist_update(cl);
891 }
892 
893 static void
894 update_d(struct hfsc_class *cl, int next_len)
895 {
896 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
897 }
898 
899 static void
900 init_vf(struct hfsc_class *cl, int len)
901 {
902 	struct hfsc_class *max_cl, *p;
903 	uint64_t vt, f, cur_time;
904 	int go_active;
905 
906 	cur_time = 0;
907 	go_active = 1;
908 	for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) {
909 		if (go_active && cl->cl_nactive++ == 0)
910 			go_active = 1;
911 		else
912 			go_active = 0;
913 
914 		if (go_active) {
915 			max_cl = actlist_last(cl->cl_parent->cl_actc);
916 			if (max_cl != NULL) {
917 				/*
918 				 * set vt to the average of the min and max
919 				 * classes.  if the parent's period didn't
920 				 * change, don't decrease vt of the class.
921 				 */
922 				vt = max_cl->cl_vt;
923 				if (cl->cl_parent->cl_cvtmin != 0)
924 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
925 
926 				if (cl->cl_parent->cl_vtperiod !=
927 				    cl->cl_parentperiod || vt > cl->cl_vt)
928 					cl->cl_vt = vt;
929 			} else {
930 				/*
931 				 * first child for a new parent backlog period.
932 				 * add parent's cvtmax to vtoff of children
933 				 * to make a new vt (vtoff + vt) larger than
934 				 * the vt in the last period for all children.
935 				 */
936 				vt = cl->cl_parent->cl_cvtmax;
937 				for (p = cl->cl_parent->cl_children; p != NULL;
938 				     p = p->cl_siblings)
939 					p->cl_vtoff += vt;
940 				cl->cl_vt = 0;
941 				cl->cl_parent->cl_cvtmax = 0;
942 				cl->cl_parent->cl_cvtmin = 0;
943 			}
944 			cl->cl_initvt = cl->cl_vt;
945 
946 			/* update the virtual curve */
947 			vt = cl->cl_vt + cl->cl_vtoff;
948 			rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total);
949 			if (cl->cl_virtual.x == vt) {
950 				cl->cl_virtual.x -= cl->cl_vtoff;
951 				cl->cl_vtoff = 0;
952 			}
953 			cl->cl_vtadj = 0;
954 
955 			cl->cl_vtperiod++;  /* increment vt period */
956 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
957 			if (cl->cl_parent->cl_nactive == 0)
958 				cl->cl_parentperiod++;
959 			cl->cl_f = 0;
960 
961 			actlist_insert(cl);
962 
963 			if (cl->cl_usc != NULL) {
964 				/* class has upper limit curve */
965 				if (cur_time == 0)
966 					cur_time = read_machclk();
967 
968 				/* update the ulimit curve */
969 				rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time,
970 				    cl->cl_total);
971 				/* compute myf */
972 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
973 				    cl->cl_total);
974 				cl->cl_myfadj = 0;
975 			}
976 		}
977 
978 		if (cl->cl_myf > cl->cl_cfmin)
979 			f = cl->cl_myf;
980 		else
981 			f = cl->cl_cfmin;
982 		if (f != cl->cl_f) {
983 			cl->cl_f = f;
984 			update_cfmin(cl->cl_parent);
985 		}
986 	}
987 }
988 
989 static void
990 update_vf(struct hfsc_class *cl, int len, uint64_t cur_time)
991 {
992 	uint64_t f, myf_bound, delta;
993 	int go_passive;
994 
995 	go_passive = qempty(cl->cl_q);
996 
997 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
998 		cl->cl_total += len;
999 
1000 		if (cl->cl_fsc == NULL || cl->cl_nactive == 0)
1001 			continue;
1002 
1003 		if (go_passive && --cl->cl_nactive == 0)
1004 			go_passive = 1;
1005 		else
1006 			go_passive = 0;
1007 
1008 		if (go_passive) {
1009 			/* no more active child, going passive */
1010 
1011 			/* update cvtmax of the parent class */
1012 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
1013 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
1014 
1015 			/* remove this class from the vt list */
1016 			actlist_remove(cl);
1017 
1018 			update_cfmin(cl->cl_parent);
1019 
1020 			continue;
1021 		}
1022 
1023 		/*
1024 		 * update vt and f
1025 		 */
1026 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
1027 		    - cl->cl_vtoff + cl->cl_vtadj;
1028 
1029 		/*
1030 		 * if vt of the class is smaller than cvtmin,
1031 		 * the class was skipped in the past due to non-fit.
1032 		 * if so, we need to adjust vtadj.
1033 		 */
1034 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
1035 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
1036 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
1037 		}
1038 
1039 		/* update the vt list */
1040 		actlist_update(cl);
1041 
1042 		if (cl->cl_usc != NULL) {
1043 			cl->cl_myf = cl->cl_myfadj
1044 			    + rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
1045 
1046 			/*
1047 			 * if myf lags behind by more than one clock tick
1048 			 * from the current time, adjust myfadj to prevent
1049 			 * a rate-limited class from going greedy.
1050 			 * in a steady state under rate-limiting, myf
1051 			 * fluctuates within one clock tick.
1052 			 */
1053 			myf_bound = cur_time - machclk_per_tick;
1054 			if (cl->cl_myf < myf_bound) {
1055 				delta = cur_time - cl->cl_myf;
1056 				cl->cl_myfadj += delta;
1057 				cl->cl_myf += delta;
1058 			}
1059 		}
1060 
1061 		/* cl_f is max(cl_myf, cl_cfmin) */
1062 		if (cl->cl_myf > cl->cl_cfmin)
1063 			f = cl->cl_myf;
1064 		else
1065 			f = cl->cl_cfmin;
1066 		if (f != cl->cl_f) {
1067 			cl->cl_f = f;
1068 			update_cfmin(cl->cl_parent);
1069 		}
1070 	}
1071 }
1072 
1073 static void
1074 update_cfmin(struct hfsc_class *cl)
1075 {
1076 	struct hfsc_class *p;
1077 	uint64_t cfmin;
1078 
1079 	if (TAILQ_EMPTY(cl->cl_actc)) {
1080 		cl->cl_cfmin = 0;
1081 		return;
1082 	}
1083 	cfmin = HT_INFINITY;
1084 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1085 		if (p->cl_f == 0) {
1086 			cl->cl_cfmin = 0;
1087 			return;
1088 		}
1089 		if (p->cl_f < cfmin)
1090 			cfmin = p->cl_f;
1091 	}
1092 	cl->cl_cfmin = cfmin;
1093 }
1094 
1095 /*
1096  * TAILQ based ellist and actlist implementation
1097  * (ion wanted to make a calendar queue based implementation)
1098  */
1099 /*
1100  * eligible list holds backlogged classes being sorted by their eligible times.
1101  * there is one eligible list per interface.
1102  */
1103 
1104 static ellist_t *
1105 ellist_alloc(void)
1106 {
1107 	ellist_t *head;
1108 
1109 	head = kmalloc(sizeof(ellist_t *), M_ALTQ, M_WAITOK);
1110 	TAILQ_INIT(head);
1111 	return (head);
1112 }
1113 
1114 static void
1115 ellist_destroy(ellist_t *head)
1116 {
1117 	kfree(head, M_ALTQ);
1118 }
1119 
1120 static void
1121 ellist_insert(struct hfsc_class *cl)
1122 {
1123 	struct hfsc_if *hif = cl->cl_hif;
1124 	struct hfsc_class *p;
1125 
1126 	/* check the last entry first */
1127 	if ((p = TAILQ_LAST(hif->hif_eligible, _eligible)) == NULL ||
1128 	    p->cl_e <= cl->cl_e) {
1129 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1130 		return;
1131 	}
1132 
1133 	TAILQ_FOREACH(p, hif->hif_eligible, cl_ellist) {
1134 		if (cl->cl_e < p->cl_e) {
1135 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1136 			return;
1137 		}
1138 	}
1139 	KKASSERT(0); /* should not reach here */
1140 }
1141 
1142 static void
1143 ellist_remove(struct hfsc_class *cl)
1144 {
1145 	struct hfsc_if *hif = cl->cl_hif;
1146 
1147 	TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1148 }
1149 
1150 static void
1151 ellist_update(struct hfsc_class *cl)
1152 {
1153 	struct hfsc_if *hif = cl->cl_hif;
1154 	struct hfsc_class *p, *last;
1155 
1156 	/*
1157 	 * the eligible time of a class increases monotonically.
1158 	 * if the next entry has a larger eligible time, nothing to do.
1159 	 */
1160 	p = TAILQ_NEXT(cl, cl_ellist);
1161 	if (p == NULL || cl->cl_e <= p->cl_e)
1162 		return;
1163 
1164 	/* check the last entry */
1165 	last = TAILQ_LAST(hif->hif_eligible, _eligible);
1166 	KKASSERT(last != NULL);
1167 	if (last->cl_e <= cl->cl_e) {
1168 		TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1169 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1170 		return;
1171 	}
1172 
1173 	/*
1174 	 * the new position must be between the next entry
1175 	 * and the last entry
1176 	 */
1177 	while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) {
1178 		if (cl->cl_e < p->cl_e) {
1179 			TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1180 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1181 			return;
1182 		}
1183 	}
1184 	KKASSERT(0); /* should not reach here */
1185 }
1186 
1187 /* find the class with the minimum deadline among the eligible classes */
1188 struct hfsc_class *
1189 ellist_get_mindl(ellist_t *head, uint64_t cur_time)
1190 {
1191 	struct hfsc_class *p, *cl = NULL;
1192 
1193 	TAILQ_FOREACH(p, head, cl_ellist) {
1194 		if (p->cl_e > cur_time)
1195 			break;
1196 		if (cl == NULL || p->cl_d < cl->cl_d)
1197 			cl = p;
1198 	}
1199 	return (cl);
1200 }
1201 
1202 /*
1203  * active children list holds backlogged child classes being sorted
1204  * by their virtual time.
1205  * each intermediate class has one active children list.
1206  */
1207 static actlist_t *
1208 actlist_alloc(void)
1209 {
1210 	actlist_t *head;
1211 
1212 	head = kmalloc(sizeof(*head), M_ALTQ, M_WAITOK);
1213 	TAILQ_INIT(head);
1214 	return (head);
1215 }
1216 
1217 static void
1218 actlist_destroy(actlist_t *head)
1219 {
1220 	kfree(head, M_ALTQ);
1221 }
1222 static void
1223 actlist_insert(struct hfsc_class *cl)
1224 {
1225 	struct hfsc_class *p;
1226 
1227 	/* check the last entry first */
1228 	if ((p = TAILQ_LAST(cl->cl_parent->cl_actc, _active)) == NULL
1229 	    || p->cl_vt <= cl->cl_vt) {
1230 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1231 		return;
1232 	}
1233 
1234 	TAILQ_FOREACH(p, cl->cl_parent->cl_actc, cl_actlist) {
1235 		if (cl->cl_vt < p->cl_vt) {
1236 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1237 			return;
1238 		}
1239 	}
1240 	KKASSERT(0); /* should not reach here */
1241 }
1242 
1243 static void
1244 actlist_remove(struct hfsc_class *cl)
1245 {
1246 	TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1247 }
1248 
1249 static void
1250 actlist_update(struct hfsc_class *cl)
1251 {
1252 	struct hfsc_class *p, *last;
1253 
1254 	/*
1255 	 * the virtual time of a class increases monotonically during its
1256 	 * backlogged period.
1257 	 * if the next entry has a larger virtual time, nothing to do.
1258 	 */
1259 	p = TAILQ_NEXT(cl, cl_actlist);
1260 	if (p == NULL || cl->cl_vt < p->cl_vt)
1261 		return;
1262 
1263 	/* check the last entry */
1264 	last = TAILQ_LAST(cl->cl_parent->cl_actc, _active);
1265 	KKASSERT(last != NULL);
1266 	if (last->cl_vt <= cl->cl_vt) {
1267 		TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1268 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1269 		return;
1270 	}
1271 
1272 	/*
1273 	 * the new position must be between the next entry
1274 	 * and the last entry
1275 	 */
1276 	while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) {
1277 		if (cl->cl_vt < p->cl_vt) {
1278 			TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1279 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1280 			return;
1281 		}
1282 	}
1283 	KKASSERT(0); /* should not reach here */
1284 }
1285 
1286 static struct hfsc_class *
1287 actlist_firstfit(struct hfsc_class *cl, uint64_t cur_time)
1288 {
1289 	struct hfsc_class *p;
1290 
1291 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1292 		if (p->cl_f <= cur_time)
1293 			return (p);
1294 	}
1295 	return (NULL);
1296 }
1297 
1298 /*
1299  * service curve support functions
1300  *
1301  *  external service curve parameters
1302  *	m: bits/sec
1303  *	d: msec
1304  *  internal service curve parameters
1305  *	sm: (bytes/tsc_interval) << SM_SHIFT
1306  *	ism: (tsc_count/byte) << ISM_SHIFT
1307  *	dx: tsc_count
1308  *
1309  * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits.
1310  * we should be able to handle 100K-1Gbps linkspeed with 200Hz-1GHz CPU
1311  * speed.  SM_SHIFT and ISM_SHIFT are selected to have at least 3 effective
1312  * digits in decimal using the following table.
1313  *
1314  *  bits/sec    100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
1315  *  ----------+-------------------------------------------------------
1316  *  bytes/nsec  12.5e-6    125e-6     1250e-6    12500e-6   125000e-6
1317  *  sm(500MHz)  25.0e-6    250e-6     2500e-6    25000e-6   250000e-6
1318  *  sm(200MHz)  62.5e-6    625e-6     6250e-6    62500e-6   625000e-6
1319  *
1320  *  nsec/byte   80000      8000       800        80         8
1321  *  ism(500MHz) 40000      4000       400        40         4
1322  *  ism(200MHz) 16000      1600       160        16         1.6
1323  */
1324 #define	SM_SHIFT	24
1325 #define	ISM_SHIFT	10
1326 
1327 #define	SM_MASK		((1LL << SM_SHIFT) - 1)
1328 #define	ISM_MASK	((1LL << ISM_SHIFT) - 1)
1329 
1330 static __inline uint64_t
1331 seg_x2y(uint64_t x, uint64_t sm)
1332 {
1333 	uint64_t y;
1334 
1335 	/*
1336 	 * compute
1337 	 *	y = x * sm >> SM_SHIFT
1338 	 * but divide it for the upper and lower bits to avoid overflow
1339 	 */
1340 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
1341 	return (y);
1342 }
1343 
1344 static __inline uint64_t
1345 seg_y2x(uint64_t y, uint64_t ism)
1346 {
1347 	uint64_t x;
1348 
1349 	if (y == 0)
1350 		x = 0;
1351 	else if (ism == HT_INFINITY)
1352 		x = HT_INFINITY;
1353 	else
1354 		x = (y >> ISM_SHIFT) * ism + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
1355 
1356 	return (x);
1357 }
1358 
1359 static __inline uint64_t
1360 m2sm(u_int m)
1361 {
1362 	uint64_t sm;
1363 
1364 	sm = ((uint64_t)m << SM_SHIFT) / 8 / machclk_freq;
1365 	return (sm);
1366 }
1367 
1368 static __inline uint64_t
1369 m2ism(u_int m)
1370 {
1371 	uint64_t ism;
1372 
1373 	if (m == 0)
1374 		ism = HT_INFINITY;
1375 	else
1376 		ism = ((uint64_t)machclk_freq << ISM_SHIFT) * 8 / m;
1377 	return (ism);
1378 }
1379 
1380 static __inline uint64_t
1381 d2dx(u_int d)
1382 {
1383 	uint64_t dx;
1384 
1385 	dx = ((uint64_t)d * machclk_freq) / 1000;
1386 	return (dx);
1387 }
1388 
1389 static u_int
1390 sm2m(uint64_t sm)
1391 {
1392 	uint64_t m;
1393 
1394 	m = (sm * 8 * machclk_freq) >> SM_SHIFT;
1395 	return ((u_int)m);
1396 }
1397 
1398 static u_int
1399 dx2d(uint64_t dx)
1400 {
1401 	uint64_t d;
1402 
1403 	d = dx * 1000 / machclk_freq;
1404 	return ((u_int)d);
1405 }
1406 
1407 static void
1408 sc2isc(struct service_curve *sc, struct internal_sc *isc)
1409 {
1410 	isc->sm1 = m2sm(sc->m1);
1411 	isc->ism1 = m2ism(sc->m1);
1412 	isc->dx = d2dx(sc->d);
1413 	isc->dy = seg_x2y(isc->dx, isc->sm1);
1414 	isc->sm2 = m2sm(sc->m2);
1415 	isc->ism2 = m2ism(sc->m2);
1416 }
1417 
1418 /*
1419  * initialize the runtime service curve with the given internal
1420  * service curve starting at (x, y).
1421  */
1422 static void
1423 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1424 {
1425 	rtsc->x = x;
1426 	rtsc->y = y;
1427 	rtsc->sm1 = isc->sm1;
1428 	rtsc->ism1 = isc->ism1;
1429 	rtsc->dx = isc->dx;
1430 	rtsc->dy = isc->dy;
1431 	rtsc->sm2 = isc->sm2;
1432 	rtsc->ism2 = isc->ism2;
1433 }
1434 
1435 /*
1436  * calculate the y-projection of the runtime service curve by the
1437  * given x-projection value
1438  */
1439 static uint64_t
1440 rtsc_y2x(struct runtime_sc *rtsc, uint64_t y)
1441 {
1442 	uint64_t x;
1443 
1444 	if (y < rtsc->y) {
1445 		x = rtsc->x;
1446 	} else if (y <= rtsc->y + rtsc->dy) {
1447 		/* x belongs to the 1st segment */
1448 		if (rtsc->dy == 0)
1449 			x = rtsc->x + rtsc->dx;
1450 		else
1451 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
1452 	} else {
1453 		/* x belongs to the 2nd segment */
1454 		x = rtsc->x + rtsc->dx
1455 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
1456 	}
1457 	return (x);
1458 }
1459 
1460 static uint64_t
1461 rtsc_x2y(struct runtime_sc *rtsc, uint64_t x)
1462 {
1463 	uint64_t y;
1464 
1465 	if (x <= rtsc->x) {
1466 		y = rtsc->y;
1467 	} else if (x <= rtsc->x + rtsc->dx) {
1468 		/* y belongs to the 1st segment */
1469 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
1470 	} else
1471 		/* y belongs to the 2nd segment */
1472 		y = rtsc->y + rtsc->dy
1473 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
1474 	return (y);
1475 }
1476 
1477 /*
1478  * update the runtime service curve by taking the minimum of the current
1479  * runtime service curve and the service curve starting at (x, y).
1480  */
1481 static void
1482 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1483 {
1484 	uint64_t y1, y2, dx, dy;
1485 
1486 	if (isc->sm1 <= isc->sm2) {
1487 		/* service curve is convex */
1488 		y1 = rtsc_x2y(rtsc, x);
1489 		if (y1 < y)
1490 			/* the current rtsc is smaller */
1491 			return;
1492 		rtsc->x = x;
1493 		rtsc->y = y;
1494 		return;
1495 	}
1496 
1497 	/*
1498 	 * service curve is concave
1499 	 * compute the two y values of the current rtsc
1500 	 *	y1: at x
1501 	 *	y2: at (x + dx)
1502 	 */
1503 	y1 = rtsc_x2y(rtsc, x);
1504 	if (y1 <= y) {
1505 		/* rtsc is below isc, no change to rtsc */
1506 		return;
1507 	}
1508 
1509 	y2 = rtsc_x2y(rtsc, x + isc->dx);
1510 	if (y2 >= y + isc->dy) {
1511 		/* rtsc is above isc, replace rtsc by isc */
1512 		rtsc->x = x;
1513 		rtsc->y = y;
1514 		rtsc->dx = isc->dx;
1515 		rtsc->dy = isc->dy;
1516 		return;
1517 	}
1518 
1519 	/*
1520 	 * the two curves intersect
1521 	 * compute the offsets (dx, dy) using the reverse
1522 	 * function of seg_x2y()
1523 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
1524 	 */
1525 	dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2);
1526 	/*
1527 	 * check if (x, y1) belongs to the 1st segment of rtsc.
1528 	 * if so, add the offset.
1529 	 */
1530 	if (rtsc->x + rtsc->dx > x)
1531 		dx += rtsc->x + rtsc->dx - x;
1532 	dy = seg_x2y(dx, isc->sm1);
1533 
1534 	rtsc->x = x;
1535 	rtsc->y = y;
1536 	rtsc->dx = dx;
1537 	rtsc->dy = dy;
1538 }
1539 
1540 static void
1541 get_class_stats(struct hfsc_classstats *sp, struct hfsc_class *cl)
1542 {
1543 	sp->class_id = cl->cl_id;
1544 	sp->class_handle = cl->cl_handle;
1545 
1546 	if (cl->cl_rsc != NULL) {
1547 		sp->rsc.m1 = sm2m(cl->cl_rsc->sm1);
1548 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1549 		sp->rsc.m2 = sm2m(cl->cl_rsc->sm2);
1550 	} else {
1551 		sp->rsc.m1 = 0;
1552 		sp->rsc.d = 0;
1553 		sp->rsc.m2 = 0;
1554 	}
1555 	if (cl->cl_fsc != NULL) {
1556 		sp->fsc.m1 = sm2m(cl->cl_fsc->sm1);
1557 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1558 		sp->fsc.m2 = sm2m(cl->cl_fsc->sm2);
1559 	} else {
1560 		sp->fsc.m1 = 0;
1561 		sp->fsc.d = 0;
1562 		sp->fsc.m2 = 0;
1563 	}
1564 	if (cl->cl_usc != NULL) {
1565 		sp->usc.m1 = sm2m(cl->cl_usc->sm1);
1566 		sp->usc.d = dx2d(cl->cl_usc->dx);
1567 		sp->usc.m2 = sm2m(cl->cl_usc->sm2);
1568 	} else {
1569 		sp->usc.m1 = 0;
1570 		sp->usc.d = 0;
1571 		sp->usc.m2 = 0;
1572 	}
1573 
1574 	sp->total = cl->cl_total;
1575 	sp->cumul = cl->cl_cumul;
1576 
1577 	sp->d = cl->cl_d;
1578 	sp->e = cl->cl_e;
1579 	sp->vt = cl->cl_vt;
1580 	sp->f = cl->cl_f;
1581 
1582 	sp->initvt = cl->cl_initvt;
1583 	sp->vtperiod = cl->cl_vtperiod;
1584 	sp->parentperiod = cl->cl_parentperiod;
1585 	sp->nactive = cl->cl_nactive;
1586 	sp->vtoff = cl->cl_vtoff;
1587 	sp->cvtmax = cl->cl_cvtmax;
1588 	sp->myf = cl->cl_myf;
1589 	sp->cfmin = cl->cl_cfmin;
1590 	sp->cvtmin = cl->cl_cvtmin;
1591 	sp->myfadj = cl->cl_myfadj;
1592 	sp->vtadj = cl->cl_vtadj;
1593 
1594 	sp->cur_time = read_machclk();
1595 	sp->machclk_freq = machclk_freq;
1596 
1597 	sp->qlength = qlen(cl->cl_q);
1598 	sp->qlimit = qlimit(cl->cl_q);
1599 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1600 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1601 	sp->period = cl->cl_stats.period;
1602 
1603 	sp->qtype = qtype(cl->cl_q);
1604 #ifdef ALTQ_RED
1605 	if (q_is_red(cl->cl_q))
1606 		red_getstats(cl->cl_red, &sp->red[0]);
1607 #endif
1608 #ifdef ALTQ_RIO
1609 	if (q_is_rio(cl->cl_q))
1610 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1611 #endif
1612 }
1613 
1614 /* convert a class handle to the corresponding class pointer */
1615 static struct hfsc_class *
1616 clh_to_clp(struct hfsc_if *hif, uint32_t chandle)
1617 {
1618 	int i;
1619 	struct hfsc_class *cl;
1620 
1621 	if (chandle == 0)
1622 		return (NULL);
1623 	/*
1624 	 * first, try optimistically the slot matching the lower bits of
1625 	 * the handle.  if it fails, do the linear table search.
1626 	 */
1627 	i = chandle % HFSC_MAX_CLASSES;
1628 	if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle)
1629 		return (cl);
1630 	for (i = 0; i < HFSC_MAX_CLASSES; i++)
1631 		if ((cl = hif->hif_class_tbl[i]) != NULL &&
1632 		    cl->cl_handle == chandle)
1633 			return (cl);
1634 	return (NULL);
1635 }
1636 
1637 #endif /* ALTQ_HFSC */
1638