xref: /dragonfly/sys/net/altq/altq_hfsc.c (revision 52f9f0d9)
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 /*
70  * function prototypes
71  */
72 static int	hfsc_clear_interface(struct hfsc_if *);
73 static int	hfsc_request(struct ifaltq *, int, void *);
74 static void	hfsc_purge(struct hfsc_if *);
75 static struct hfsc_class *hfsc_class_create(struct hfsc_if *,
76 					    struct service_curve *,
77 					    struct service_curve *,
78 					    struct service_curve *,
79 					    struct hfsc_class *, int, int, int);
80 static int	hfsc_class_destroy(struct hfsc_class *);
81 static struct hfsc_class *hfsc_nextclass(struct hfsc_class *);
82 static int	hfsc_enqueue(struct ifaltq *, struct mbuf *,
83 			     struct altq_pktattr *);
84 static struct mbuf *hfsc_dequeue(struct ifaltq *, struct mbuf *, int);
85 
86 static int	hfsc_addq(struct hfsc_class *, struct mbuf *);
87 static struct mbuf *hfsc_getq(struct hfsc_class *);
88 static struct mbuf *hfsc_pollq(struct hfsc_class *);
89 static void	hfsc_purgeq(struct hfsc_class *);
90 
91 static void	update_cfmin(struct hfsc_class *);
92 static void	set_active(struct hfsc_class *, int);
93 static void	set_passive(struct hfsc_class *);
94 
95 static void	init_ed(struct hfsc_class *, int);
96 static void	update_ed(struct hfsc_class *, int);
97 static void	update_d(struct hfsc_class *, int);
98 static void	init_vf(struct hfsc_class *, int);
99 static void	update_vf(struct hfsc_class *, int, uint64_t);
100 static ellist_t *ellist_alloc(void);
101 static void	ellist_destroy(ellist_t *);
102 static void	ellist_insert(struct hfsc_class *);
103 static void	ellist_remove(struct hfsc_class *);
104 static void	ellist_update(struct hfsc_class *);
105 struct hfsc_class *ellist_get_mindl(ellist_t *, uint64_t);
106 static actlist_t *actlist_alloc(void);
107 static void	actlist_destroy(actlist_t *);
108 static void	actlist_insert(struct hfsc_class *);
109 static void	actlist_remove(struct hfsc_class *);
110 static void	actlist_update(struct hfsc_class *);
111 
112 static struct hfsc_class *actlist_firstfit(struct hfsc_class *, uint64_t);
113 
114 static __inline uint64_t	seg_x2y(uint64_t, uint64_t);
115 static __inline uint64_t	seg_y2x(uint64_t, uint64_t);
116 static __inline uint64_t	m2sm(u_int);
117 static __inline uint64_t	m2ism(u_int);
118 static __inline uint64_t	d2dx(u_int);
119 static u_int			sm2m(uint64_t);
120 static u_int			dx2d(uint64_t);
121 
122 static void	sc2isc(struct service_curve *, struct internal_sc *);
123 static void	rtsc_init(struct runtime_sc *, struct internal_sc *,
124 			  uint64_t, uint64_t);
125 static uint64_t	rtsc_y2x(struct runtime_sc *, uint64_t);
126 static uint64_t	rtsc_x2y(struct runtime_sc *, uint64_t);
127 static void	rtsc_min(struct runtime_sc *, struct internal_sc *,
128 			 uint64_t, uint64_t);
129 
130 static void	get_class_stats(struct hfsc_classstats *, struct hfsc_class *);
131 static struct hfsc_class *clh_to_clp(struct hfsc_if *, uint32_t);
132 
133 /*
134  * macros
135  */
136 #define	is_a_parent_class(cl)	((cl)->cl_children != NULL)
137 
138 #define	HT_INFINITY	0xffffffffffffffffLL	/* infinite time value */
139 
140 int
141 hfsc_pfattach(struct pf_altq *a, struct ifaltq *ifq)
142 {
143 	return altq_attach(ifq, ALTQT_HFSC, a->altq_disc,
144 	    hfsc_enqueue, hfsc_dequeue, hfsc_request, NULL, NULL);
145 }
146 
147 int
148 hfsc_add_altq(struct pf_altq *a)
149 {
150 	struct hfsc_if *hif;
151 	struct ifnet *ifp;
152 
153 	if ((ifp = ifunit(a->ifname)) == NULL)
154 		return (EINVAL);
155 	if (!ifq_is_ready(&ifp->if_snd))
156 		return (ENODEV);
157 
158 	hif = kmalloc(sizeof(struct hfsc_if), M_ALTQ, M_WAITOK | M_ZERO);
159 
160 	hif->hif_eligible = ellist_alloc();
161 	hif->hif_ifq = &ifp->if_snd;
162 	ifq_purge(&ifp->if_snd);
163 
164 	/* keep the state in pf_altq */
165 	a->altq_disc = hif;
166 
167 	return (0);
168 }
169 
170 int
171 hfsc_remove_altq(struct pf_altq *a)
172 {
173 	struct hfsc_if *hif;
174 
175 	if ((hif = a->altq_disc) == NULL)
176 		return (EINVAL);
177 	a->altq_disc = NULL;
178 
179 	hfsc_clear_interface(hif);
180 	hfsc_class_destroy(hif->hif_rootclass);
181 
182 	ellist_destroy(hif->hif_eligible);
183 
184 	kfree(hif, M_ALTQ);
185 
186 	return (0);
187 }
188 
189 static int
190 hfsc_add_queue_locked(struct pf_altq *a, struct hfsc_if *hif)
191 {
192 	struct hfsc_class *cl, *parent;
193 	struct hfsc_opts *opts;
194 	struct service_curve rtsc, lssc, ulsc;
195 
196 	KKASSERT(a->qid != 0);
197 
198 	opts = &a->pq_u.hfsc_opts;
199 
200 	if (a->parent_qid == HFSC_NULLCLASS_HANDLE && hif->hif_rootclass == NULL)
201 		parent = NULL;
202 	else if ((parent = clh_to_clp(hif, a->parent_qid)) == NULL)
203 		return (EINVAL);
204 
205 	if (clh_to_clp(hif, a->qid) != NULL)
206 		return (EBUSY);
207 
208 	rtsc.m1 = opts->rtsc_m1;
209 	rtsc.d  = opts->rtsc_d;
210 	rtsc.m2 = opts->rtsc_m2;
211 	lssc.m1 = opts->lssc_m1;
212 	lssc.d  = opts->lssc_d;
213 	lssc.m2 = opts->lssc_m2;
214 	ulsc.m1 = opts->ulsc_m1;
215 	ulsc.d  = opts->ulsc_d;
216 	ulsc.m2 = opts->ulsc_m2;
217 
218 	cl = hfsc_class_create(hif, &rtsc, &lssc, &ulsc, parent, a->qlimit,
219 			       opts->flags, a->qid);
220 	if (cl == NULL)
221 		return (ENOMEM);
222 
223 	return (0);
224 }
225 
226 int
227 hfsc_add_queue(struct pf_altq *a)
228 {
229 	struct hfsc_if *hif;
230 	struct ifaltq *ifq;
231 	int error;
232 
233 	if (a->qid == 0)
234 		return (EINVAL);
235 
236 	/* XXX not MP safe */
237 	if ((hif = a->altq_disc) == NULL)
238 		return (EINVAL);
239 	ifq = hif->hif_ifq;
240 
241 	ALTQ_LOCK(ifq);
242 	error = hfsc_add_queue_locked(a, hif);
243 	ALTQ_UNLOCK(ifq);
244 
245 	return error;
246 }
247 
248 static int
249 hfsc_remove_queue_locked(struct pf_altq *a, struct hfsc_if *hif)
250 {
251 	struct hfsc_class *cl;
252 
253 	if ((cl = clh_to_clp(hif, a->qid)) == NULL)
254 		return (EINVAL);
255 
256 	return (hfsc_class_destroy(cl));
257 }
258 
259 int
260 hfsc_remove_queue(struct pf_altq *a)
261 {
262 	struct hfsc_if *hif;
263 	struct ifaltq *ifq;
264 	int error;
265 
266 	/* XXX not MP safe */
267 	if ((hif = a->altq_disc) == NULL)
268 		return (EINVAL);
269 	ifq = hif->hif_ifq;
270 
271 	ALTQ_LOCK(ifq);
272 	error = hfsc_remove_queue_locked(a, hif);
273 	ALTQ_UNLOCK(ifq);
274 
275 	return error;
276 }
277 
278 int
279 hfsc_getqstats(struct pf_altq *a, void *ubuf, int *nbytes)
280 {
281 	struct hfsc_if *hif;
282 	struct hfsc_class *cl;
283 	struct hfsc_classstats stats;
284 	struct ifaltq *ifq;
285 	int error = 0;
286 
287 	if (*nbytes < sizeof(stats))
288 		return (EINVAL);
289 
290 	/* XXX not MP safe */
291 	if ((hif = altq_lookup(a->ifname, ALTQT_HFSC)) == NULL)
292 		return (EBADF);
293 	ifq = hif->hif_ifq;
294 
295 	ALTQ_LOCK(ifq);
296 
297 	if ((cl = clh_to_clp(hif, a->qid)) == NULL) {
298 		ALTQ_UNLOCK(ifq);
299 		return (EINVAL);
300 	}
301 
302 	get_class_stats(&stats, cl);
303 
304 	ALTQ_UNLOCK(ifq);
305 
306 	if ((error = copyout((caddr_t)&stats, ubuf, sizeof(stats))) != 0)
307 		return (error);
308 	*nbytes = sizeof(stats);
309 	return (0);
310 }
311 
312 /*
313  * bring the interface back to the initial state by discarding
314  * all the filters and classes except the root class.
315  */
316 static int
317 hfsc_clear_interface(struct hfsc_if *hif)
318 {
319 	struct hfsc_class *cl;
320 
321 	if (hif->hif_rootclass == NULL)
322 		return (0);
323 
324 
325 	/* clear out the classes */
326 	while ((cl = hif->hif_rootclass->cl_children) != NULL) {
327 		/*
328 		 * remove the first leaf class found in the hierarchy
329 		 * then start over
330 		 */
331 		for (; cl != NULL; cl = hfsc_nextclass(cl)) {
332 			if (!is_a_parent_class(cl)) {
333 				hfsc_class_destroy(cl);
334 				break;
335 			}
336 		}
337 	}
338 
339 	return (0);
340 }
341 
342 static int
343 hfsc_request(struct ifaltq *ifq, int req, void *arg)
344 {
345 	struct hfsc_if *hif = (struct hfsc_if *)ifq->altq_disc;
346 
347 	crit_enter();
348 	switch (req) {
349 	case ALTRQ_PURGE:
350 		hfsc_purge(hif);
351 		break;
352 	}
353 	crit_exit();
354 	return (0);
355 }
356 
357 /* discard all the queued packets on the interface */
358 static void
359 hfsc_purge(struct hfsc_if *hif)
360 {
361 	struct hfsc_class *cl;
362 
363 	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl)) {
364 		if (!qempty(cl->cl_q))
365 			hfsc_purgeq(cl);
366 	}
367 	if (ifq_is_enabled(hif->hif_ifq))
368 		hif->hif_ifq->ifq_len = 0;
369 }
370 
371 struct hfsc_class *
372 hfsc_class_create(struct hfsc_if *hif, struct service_curve *rsc,
373 		  struct service_curve *fsc, struct service_curve *usc,
374 		  struct hfsc_class *parent, int qlimit, int flags, int qid)
375 {
376 	struct hfsc_class *cl, *p;
377 	int i;
378 
379 	if (hif->hif_classes >= HFSC_MAX_CLASSES)
380 		return (NULL);
381 
382 #ifndef ALTQ_RED
383 	if (flags & HFCF_RED) {
384 #ifdef ALTQ_DEBUG
385 		kprintf("hfsc_class_create: RED not configured for HFSC!\n");
386 #endif
387 		return (NULL);
388 	}
389 #endif
390 
391 	cl = kmalloc(sizeof(*cl), M_ALTQ, M_WAITOK | M_ZERO);
392 	cl->cl_q = kmalloc(sizeof(*cl->cl_q), M_ALTQ, M_WAITOK | M_ZERO);
393 	cl->cl_actc = actlist_alloc();
394 
395 	if (qlimit == 0)
396 		qlimit = 50;  /* use default */
397 	qlimit(cl->cl_q) = qlimit;
398 	qtype(cl->cl_q) = Q_DROPTAIL;
399 	qlen(cl->cl_q) = 0;
400 	cl->cl_flags = flags;
401 #ifdef ALTQ_RED
402 	if (flags & (HFCF_RED|HFCF_RIO)) {
403 		int red_flags, red_pkttime;
404 		u_int m2;
405 
406 		m2 = 0;
407 		if (rsc != NULL && rsc->m2 > m2)
408 			m2 = rsc->m2;
409 		if (fsc != NULL && fsc->m2 > m2)
410 			m2 = fsc->m2;
411 		if (usc != NULL && usc->m2 > m2)
412 			m2 = usc->m2;
413 
414 		red_flags = 0;
415 		if (flags & HFCF_ECN)
416 			red_flags |= REDF_ECN;
417 #ifdef ALTQ_RIO
418 		if (flags & HFCF_CLEARDSCP)
419 			red_flags |= RIOF_CLEARDSCP;
420 #endif
421 		if (m2 < 8)
422 			red_pkttime = 1000 * 1000 * 1000; /* 1 sec */
423 		else
424 			red_pkttime = (int64_t)hif->hif_ifq->altq_ifp->if_mtu
425 				* 1000 * 1000 * 1000 / (m2 / 8);
426 		if (flags & HFCF_RED) {
427 			cl->cl_red = red_alloc(0, 0,
428 			    qlimit(cl->cl_q) * 10/100,
429 			    qlimit(cl->cl_q) * 30/100,
430 			    red_flags, red_pkttime);
431 			if (cl->cl_red != NULL)
432 				qtype(cl->cl_q) = Q_RED;
433 		}
434 #ifdef ALTQ_RIO
435 		else {
436 			cl->cl_red = (red_t *)rio_alloc(0, NULL,
437 			    red_flags, red_pkttime);
438 			if (cl->cl_red != NULL)
439 				qtype(cl->cl_q) = Q_RIO;
440 		}
441 #endif
442 	}
443 #endif /* ALTQ_RED */
444 
445 	if (rsc != NULL && (rsc->m1 != 0 || rsc->m2 != 0)) {
446 		cl->cl_rsc = kmalloc(sizeof(*cl->cl_rsc), M_ALTQ, M_WAITOK);
447 		sc2isc(rsc, cl->cl_rsc);
448 		rtsc_init(&cl->cl_deadline, cl->cl_rsc, 0, 0);
449 		rtsc_init(&cl->cl_eligible, cl->cl_rsc, 0, 0);
450 	}
451 	if (fsc != NULL && (fsc->m1 != 0 || fsc->m2 != 0)) {
452 		cl->cl_fsc = kmalloc(sizeof(*cl->cl_fsc), M_ALTQ, M_WAITOK);
453 		sc2isc(fsc, cl->cl_fsc);
454 		rtsc_init(&cl->cl_virtual, cl->cl_fsc, 0, 0);
455 	}
456 	if (usc != NULL && (usc->m1 != 0 || usc->m2 != 0)) {
457 		cl->cl_usc = kmalloc(sizeof(*cl->cl_usc), M_ALTQ, M_WAITOK);
458 		sc2isc(usc, cl->cl_usc);
459 		rtsc_init(&cl->cl_ulimit, cl->cl_usc, 0, 0);
460 	}
461 
462 	cl->cl_id = hif->hif_classid++;
463 	cl->cl_handle = qid;
464 	cl->cl_hif = hif;
465 	cl->cl_parent = parent;
466 
467 	crit_enter();
468 	hif->hif_classes++;
469 
470 	/*
471 	 * find a free slot in the class table.  if the slot matching
472 	 * the lower bits of qid is free, use this slot.  otherwise,
473 	 * use the first free slot.
474 	 */
475 	i = qid % HFSC_MAX_CLASSES;
476 	if (hif->hif_class_tbl[i] == NULL)
477 		hif->hif_class_tbl[i] = cl;
478 	else {
479 		for (i = 0; i < HFSC_MAX_CLASSES; i++) {
480 			if (hif->hif_class_tbl[i] == NULL) {
481 				hif->hif_class_tbl[i] = cl;
482 				break;
483 			}
484 		}
485 		if (i == HFSC_MAX_CLASSES) {
486 			crit_exit();
487 			goto err_ret;
488 		}
489 	}
490 
491 	if (flags & HFCF_DEFAULTCLASS)
492 		hif->hif_defaultclass = cl;
493 
494 	if (parent == NULL) {
495 		/* this is root class */
496 		hif->hif_rootclass = cl;
497 	} else if (parent->cl_children == NULL) {
498 		/* add this class to the children list of the parent */
499 		parent->cl_children = cl;
500 	} else {
501 		p = parent->cl_children;
502 		while (p->cl_siblings != NULL)
503 			p = p->cl_siblings;
504 		p->cl_siblings = cl;
505 	}
506 	crit_exit();
507 
508 	return (cl);
509 
510  err_ret:
511 	if (cl->cl_actc != NULL)
512 		actlist_destroy(cl->cl_actc);
513 	if (cl->cl_red != NULL) {
514 #ifdef ALTQ_RIO
515 		if (q_is_rio(cl->cl_q))
516 			rio_destroy((rio_t *)cl->cl_red);
517 #endif
518 #ifdef ALTQ_RED
519 		if (q_is_red(cl->cl_q))
520 			red_destroy(cl->cl_red);
521 #endif
522 	}
523 	if (cl->cl_fsc != NULL)
524 		kfree(cl->cl_fsc, M_ALTQ);
525 	if (cl->cl_rsc != NULL)
526 		kfree(cl->cl_rsc, M_ALTQ);
527 	if (cl->cl_usc != NULL)
528 		kfree(cl->cl_usc, M_ALTQ);
529 	if (cl->cl_q != NULL)
530 		kfree(cl->cl_q, M_ALTQ);
531 	kfree(cl, M_ALTQ);
532 	return (NULL);
533 }
534 
535 static int
536 hfsc_class_destroy(struct hfsc_class *cl)
537 {
538 	struct hfsc_if *hif;
539 	int i;
540 
541 	if (cl == NULL)
542 		return (0);
543 	hif = cl->cl_hif;
544 
545 	if (is_a_parent_class(cl))
546 		return (EBUSY);
547 
548 	crit_enter();
549 
550 	if (!qempty(cl->cl_q))
551 		hfsc_purgeq(cl);
552 
553 	if (cl->cl_parent == NULL) {
554 		/* this is root class */
555 	} else {
556 		struct hfsc_class *p = cl->cl_parent->cl_children;
557 
558 		if (p == cl) {
559 			cl->cl_parent->cl_children = cl->cl_siblings;
560 		} else {
561 			do {
562 				if (p->cl_siblings == cl) {
563 					p->cl_siblings = cl->cl_siblings;
564 					break;
565 				}
566 			} while ((p = p->cl_siblings) != NULL);
567 		}
568 		KKASSERT(p != NULL);
569 	}
570 
571 	for (i = 0; i < HFSC_MAX_CLASSES; i++) {
572 		if (hif->hif_class_tbl[i] == cl) {
573 			hif->hif_class_tbl[i] = NULL;
574 			break;
575 		}
576 	}
577 
578 	hif->hif_classes--;
579 	crit_exit();
580 
581 	actlist_destroy(cl->cl_actc);
582 
583 	if (cl->cl_red != NULL) {
584 #ifdef ALTQ_RIO
585 		if (q_is_rio(cl->cl_q))
586 			rio_destroy((rio_t *)cl->cl_red);
587 #endif
588 #ifdef ALTQ_RED
589 		if (q_is_red(cl->cl_q))
590 			red_destroy(cl->cl_red);
591 #endif
592 	}
593 
594 	if (cl == hif->hif_rootclass)
595 		hif->hif_rootclass = NULL;
596 	if (cl == hif->hif_defaultclass)
597 		hif->hif_defaultclass = NULL;
598 	if (cl == hif->hif_pollcache)
599 		hif->hif_pollcache = NULL;
600 
601 	if (cl->cl_usc != NULL)
602 		kfree(cl->cl_usc, M_ALTQ);
603 	if (cl->cl_fsc != NULL)
604 		kfree(cl->cl_fsc, M_ALTQ);
605 	if (cl->cl_rsc != NULL)
606 		kfree(cl->cl_rsc, M_ALTQ);
607 	kfree(cl->cl_q, M_ALTQ);
608 	kfree(cl, M_ALTQ);
609 
610 	return (0);
611 }
612 
613 /*
614  * hfsc_nextclass returns the next class in the tree.
615  *   usage:
616  *	for (cl = hif->hif_rootclass; cl != NULL; cl = hfsc_nextclass(cl))
617  *		do_something;
618  */
619 static struct hfsc_class *
620 hfsc_nextclass(struct hfsc_class *cl)
621 {
622 	if (cl->cl_children != NULL) {
623 		cl = cl->cl_children;
624 	} else if (cl->cl_siblings != NULL) {
625 		cl = cl->cl_siblings;
626 	} else {
627 		while ((cl = cl->cl_parent) != NULL) {
628 			if (cl->cl_siblings != NULL) {
629 				cl = cl->cl_siblings;
630 				break;
631 			}
632 		}
633 	}
634 
635 	return (cl);
636 }
637 
638 /*
639  * hfsc_enqueue is an enqueue function to be registered to
640  * (*altq_enqueue) in struct ifaltq.
641  */
642 static int
643 hfsc_enqueue(struct ifaltq *ifq, struct mbuf *m, struct altq_pktattr *pktattr)
644 {
645 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
646 	struct hfsc_class *cl;
647 	int len;
648 
649 	/* grab class set by classifier */
650 	if ((m->m_flags & M_PKTHDR) == 0) {
651 		/* should not happen */
652 		if_printf(ifq->altq_ifp, "altq: packet does not have pkthdr\n");
653 		m_freem(m);
654 		return (ENOBUFS);
655 	}
656 	crit_enter();
657 	if (m->m_pkthdr.fw_flags & PF_MBUF_STRUCTURE)
658 		cl = clh_to_clp(hif, m->m_pkthdr.pf.qid);
659 	else
660 		cl = NULL;
661 	if (cl == NULL || is_a_parent_class(cl)) {
662 		cl = hif->hif_defaultclass;
663 		if (cl == NULL) {
664 			m_freem(m);
665 			crit_exit();
666 			return (ENOBUFS);
667 		}
668 	}
669 	cl->cl_pktattr = NULL;
670 	len = m_pktlen(m);
671 	if (hfsc_addq(cl, m) != 0) {
672 		/* drop occurred.  mbuf was freed in hfsc_addq. */
673 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, len);
674 		crit_exit();
675 		return (ENOBUFS);
676 	}
677 	ifq->ifq_len++;
678 	cl->cl_hif->hif_packets++;
679 
680 	/* successfully queued. */
681 	if (qlen(cl->cl_q) == 1)
682 		set_active(cl, m_pktlen(m));
683 	crit_exit();
684 	return (0);
685 }
686 
687 /*
688  * hfsc_dequeue is a dequeue function to be registered to
689  * (*altq_dequeue) in struct ifaltq.
690  *
691  * note: ALTDQ_POLL returns the next packet without removing the packet
692  *	from the queue.  ALTDQ_REMOVE is a normal dequeue operation.
693  *	ALTDQ_REMOVE must return the same packet if called immediately
694  *	after ALTDQ_POLL.
695  */
696 static struct mbuf *
697 hfsc_dequeue(struct ifaltq *ifq, struct mbuf *mpolled, int op)
698 {
699 	struct hfsc_if	*hif = (struct hfsc_if *)ifq->altq_disc;
700 	struct hfsc_class *cl;
701 	struct mbuf *m;
702 	int len, next_len;
703 	int realtime = 0;
704 	uint64_t cur_time;
705 
706 	if (hif->hif_packets == 0) {
707 		/* no packet in the tree */
708 		return (NULL);
709 	}
710 
711 	crit_enter();
712 	cur_time = read_machclk();
713 
714 	if (op == ALTDQ_REMOVE && hif->hif_pollcache != NULL) {
715 		cl = hif->hif_pollcache;
716 		hif->hif_pollcache = NULL;
717 		/* check if the class was scheduled by real-time criteria */
718 		if (cl->cl_rsc != NULL)
719 			realtime = (cl->cl_e <= cur_time);
720 	} else {
721 		/*
722 		 * if there are eligible classes, use real-time criteria.
723 		 * find the class with the minimum deadline among
724 		 * the eligible classes.
725 		 */
726 		if ((cl = ellist_get_mindl(hif->hif_eligible, cur_time)) != NULL) {
727 			realtime = 1;
728 		} else {
729 #ifdef ALTQ_DEBUG
730 			int fits = 0;
731 #endif
732 			/*
733 			 * use link-sharing criteria
734 			 * get the class with the minimum vt in the hierarchy
735 			 */
736 			cl = hif->hif_rootclass;
737 			while (is_a_parent_class(cl)) {
738 
739 				cl = actlist_firstfit(cl, cur_time);
740 				if (cl == NULL) {
741 #ifdef ALTQ_DEBUG
742 					if (fits > 0)
743 						kprintf("%d fit but none found\n",fits);
744 #endif
745 					m = NULL;
746 					goto done;
747 				}
748 				/*
749 				 * update parent's cl_cvtmin.
750 				 * don't update if the new vt is smaller.
751 				 */
752 				if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
753 					cl->cl_parent->cl_cvtmin = cl->cl_vt;
754 #ifdef ALTQ_DEBUG
755 				fits++;
756 #endif
757 			}
758 		}
759 
760 		if (op == ALTDQ_POLL) {
761 			hif->hif_pollcache = cl;
762 			m = hfsc_pollq(cl);
763 			goto done;
764 		}
765 	}
766 
767 	m = hfsc_getq(cl);
768 	if (m == NULL)
769 		panic("hfsc_dequeue:");
770 	len = m_pktlen(m);
771 	cl->cl_hif->hif_packets--;
772 	ifq->ifq_len--;
773 	PKTCNTR_ADD(&cl->cl_stats.xmit_cnt, len);
774 
775 	update_vf(cl, len, cur_time);
776 	if (realtime)
777 		cl->cl_cumul += len;
778 
779 	if (!qempty(cl->cl_q)) {
780 		if (cl->cl_rsc != NULL) {
781 			/* update ed */
782 			next_len = m_pktlen(qhead(cl->cl_q));
783 
784 			if (realtime)
785 				update_ed(cl, next_len);
786 			else
787 				update_d(cl, next_len);
788 		}
789 	} else {
790 		/* the class becomes passive */
791 		set_passive(cl);
792 	}
793 done:
794 	crit_exit();
795 	KKASSERT(mpolled == NULL || m == mpolled);
796 	return (m);
797 }
798 
799 static int
800 hfsc_addq(struct hfsc_class *cl, struct mbuf *m)
801 {
802 
803 #ifdef ALTQ_RIO
804 	if (q_is_rio(cl->cl_q))
805 		return rio_addq((rio_t *)cl->cl_red, cl->cl_q,
806 				m, cl->cl_pktattr);
807 #endif
808 #ifdef ALTQ_RED
809 	if (q_is_red(cl->cl_q))
810 		return red_addq(cl->cl_red, cl->cl_q, m, cl->cl_pktattr);
811 #endif
812 	if (qlen(cl->cl_q) >= qlimit(cl->cl_q)) {
813 		m_freem(m);
814 		return (-1);
815 	}
816 
817 	if (cl->cl_flags & HFCF_CLEARDSCP)
818 		write_dsfield(m, cl->cl_pktattr, 0);
819 
820 	_addq(cl->cl_q, m);
821 
822 	return (0);
823 }
824 
825 static struct mbuf *
826 hfsc_getq(struct hfsc_class *cl)
827 {
828 #ifdef ALTQ_RIO
829 	if (q_is_rio(cl->cl_q))
830 		return rio_getq((rio_t *)cl->cl_red, cl->cl_q);
831 #endif
832 #ifdef ALTQ_RED
833 	if (q_is_red(cl->cl_q))
834 		return red_getq(cl->cl_red, cl->cl_q);
835 #endif
836 	return _getq(cl->cl_q);
837 }
838 
839 static struct mbuf *
840 hfsc_pollq(struct hfsc_class *cl)
841 {
842 	return qhead(cl->cl_q);
843 }
844 
845 static void
846 hfsc_purgeq(struct hfsc_class *cl)
847 {
848 	struct mbuf *m;
849 
850 	if (qempty(cl->cl_q))
851 		return;
852 
853 	while ((m = _getq(cl->cl_q)) != NULL) {
854 		PKTCNTR_ADD(&cl->cl_stats.drop_cnt, m_pktlen(m));
855 		m_freem(m);
856 		cl->cl_hif->hif_packets--;
857 		cl->cl_hif->hif_ifq->ifq_len--;
858 	}
859 	KKASSERT(qlen(cl->cl_q) == 0);
860 
861 	update_vf(cl, 0, 0);	/* remove cl from the actlist */
862 	set_passive(cl);
863 }
864 
865 static void
866 set_active(struct hfsc_class *cl, int len)
867 {
868 	if (cl->cl_rsc != NULL)
869 		init_ed(cl, len);
870 	if (cl->cl_fsc != NULL)
871 		init_vf(cl, len);
872 
873 	cl->cl_stats.period++;
874 }
875 
876 static void
877 set_passive(struct hfsc_class *cl)
878 {
879 	if (cl->cl_rsc != NULL)
880 		ellist_remove(cl);
881 
882 	/*
883 	 * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
884 	 * needs to be called explicitly to remove a class from actlist
885 	 */
886 }
887 
888 static void
889 init_ed(struct hfsc_class *cl, int next_len)
890 {
891 	uint64_t cur_time;
892 
893 	cur_time = read_machclk();
894 
895 	/* update the deadline curve */
896 	rtsc_min(&cl->cl_deadline, cl->cl_rsc, cur_time, cl->cl_cumul);
897 
898 	/*
899 	 * update the eligible curve.
900 	 * for concave, it is equal to the deadline curve.
901 	 * for convex, it is a linear curve with slope m2.
902 	 */
903 	cl->cl_eligible = cl->cl_deadline;
904 	if (cl->cl_rsc->sm1 <= cl->cl_rsc->sm2) {
905 		cl->cl_eligible.dx = 0;
906 		cl->cl_eligible.dy = 0;
907 	}
908 
909 	/* compute e and d */
910 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
911 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
912 
913 	ellist_insert(cl);
914 }
915 
916 static void
917 update_ed(struct hfsc_class *cl, int next_len)
918 {
919 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
920 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
921 
922 	ellist_update(cl);
923 }
924 
925 static void
926 update_d(struct hfsc_class *cl, int next_len)
927 {
928 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
929 }
930 
931 static void
932 init_vf(struct hfsc_class *cl, int len)
933 {
934 	struct hfsc_class *max_cl, *p;
935 	uint64_t vt, f, cur_time;
936 	int go_active;
937 
938 	cur_time = 0;
939 	go_active = 1;
940 	for ( ; cl->cl_parent != NULL; cl = cl->cl_parent) {
941 		if (go_active && cl->cl_nactive++ == 0)
942 			go_active = 1;
943 		else
944 			go_active = 0;
945 
946 		if (go_active) {
947 			max_cl = actlist_last(cl->cl_parent->cl_actc);
948 			if (max_cl != NULL) {
949 				/*
950 				 * set vt to the average of the min and max
951 				 * classes.  if the parent's period didn't
952 				 * change, don't decrease vt of the class.
953 				 */
954 				vt = max_cl->cl_vt;
955 				if (cl->cl_parent->cl_cvtmin != 0)
956 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
957 
958 				if (cl->cl_parent->cl_vtperiod !=
959 				    cl->cl_parentperiod || vt > cl->cl_vt)
960 					cl->cl_vt = vt;
961 			} else {
962 				/*
963 				 * first child for a new parent backlog period.
964 				 * add parent's cvtmax to vtoff of children
965 				 * to make a new vt (vtoff + vt) larger than
966 				 * the vt in the last period for all children.
967 				 */
968 				vt = cl->cl_parent->cl_cvtmax;
969 				for (p = cl->cl_parent->cl_children; p != NULL;
970 				     p = p->cl_siblings)
971 					p->cl_vtoff += vt;
972 				cl->cl_vt = 0;
973 				cl->cl_parent->cl_cvtmax = 0;
974 				cl->cl_parent->cl_cvtmin = 0;
975 			}
976 			cl->cl_initvt = cl->cl_vt;
977 
978 			/* update the virtual curve */
979 			vt = cl->cl_vt + cl->cl_vtoff;
980 			rtsc_min(&cl->cl_virtual, cl->cl_fsc, vt, cl->cl_total);
981 			if (cl->cl_virtual.x == vt) {
982 				cl->cl_virtual.x -= cl->cl_vtoff;
983 				cl->cl_vtoff = 0;
984 			}
985 			cl->cl_vtadj = 0;
986 
987 			cl->cl_vtperiod++;  /* increment vt period */
988 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
989 			if (cl->cl_parent->cl_nactive == 0)
990 				cl->cl_parentperiod++;
991 			cl->cl_f = 0;
992 
993 			actlist_insert(cl);
994 
995 			if (cl->cl_usc != NULL) {
996 				/* class has upper limit curve */
997 				if (cur_time == 0)
998 					cur_time = read_machclk();
999 
1000 				/* update the ulimit curve */
1001 				rtsc_min(&cl->cl_ulimit, cl->cl_usc, cur_time,
1002 				    cl->cl_total);
1003 				/* compute myf */
1004 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
1005 				    cl->cl_total);
1006 				cl->cl_myfadj = 0;
1007 			}
1008 		}
1009 
1010 		if (cl->cl_myf > cl->cl_cfmin)
1011 			f = cl->cl_myf;
1012 		else
1013 			f = cl->cl_cfmin;
1014 		if (f != cl->cl_f) {
1015 			cl->cl_f = f;
1016 			update_cfmin(cl->cl_parent);
1017 		}
1018 	}
1019 }
1020 
1021 static void
1022 update_vf(struct hfsc_class *cl, int len, uint64_t cur_time)
1023 {
1024 	uint64_t f, myf_bound, delta;
1025 	int go_passive;
1026 
1027 	go_passive = qempty(cl->cl_q);
1028 
1029 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
1030 		cl->cl_total += len;
1031 
1032 		if (cl->cl_fsc == NULL || cl->cl_nactive == 0)
1033 			continue;
1034 
1035 		if (go_passive && --cl->cl_nactive == 0)
1036 			go_passive = 1;
1037 		else
1038 			go_passive = 0;
1039 
1040 		if (go_passive) {
1041 			/* no more active child, going passive */
1042 
1043 			/* update cvtmax of the parent class */
1044 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
1045 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
1046 
1047 			/* remove this class from the vt list */
1048 			actlist_remove(cl);
1049 
1050 			update_cfmin(cl->cl_parent);
1051 
1052 			continue;
1053 		}
1054 
1055 		/*
1056 		 * update vt and f
1057 		 */
1058 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
1059 		    - cl->cl_vtoff + cl->cl_vtadj;
1060 
1061 		/*
1062 		 * if vt of the class is smaller than cvtmin,
1063 		 * the class was skipped in the past due to non-fit.
1064 		 * if so, we need to adjust vtadj.
1065 		 */
1066 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
1067 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
1068 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
1069 		}
1070 
1071 		/* update the vt list */
1072 		actlist_update(cl);
1073 
1074 		if (cl->cl_usc != NULL) {
1075 			cl->cl_myf = cl->cl_myfadj
1076 			    + rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
1077 
1078 			/*
1079 			 * if myf lags behind by more than one clock tick
1080 			 * from the current time, adjust myfadj to prevent
1081 			 * a rate-limited class from going greedy.
1082 			 * in a steady state under rate-limiting, myf
1083 			 * fluctuates within one clock tick.
1084 			 */
1085 			myf_bound = cur_time - machclk_per_tick;
1086 			if (cl->cl_myf < myf_bound) {
1087 				delta = cur_time - cl->cl_myf;
1088 				cl->cl_myfadj += delta;
1089 				cl->cl_myf += delta;
1090 			}
1091 		}
1092 
1093 		/* cl_f is max(cl_myf, cl_cfmin) */
1094 		if (cl->cl_myf > cl->cl_cfmin)
1095 			f = cl->cl_myf;
1096 		else
1097 			f = cl->cl_cfmin;
1098 		if (f != cl->cl_f) {
1099 			cl->cl_f = f;
1100 			update_cfmin(cl->cl_parent);
1101 		}
1102 	}
1103 }
1104 
1105 static void
1106 update_cfmin(struct hfsc_class *cl)
1107 {
1108 	struct hfsc_class *p;
1109 	uint64_t cfmin;
1110 
1111 	if (TAILQ_EMPTY(cl->cl_actc)) {
1112 		cl->cl_cfmin = 0;
1113 		return;
1114 	}
1115 	cfmin = HT_INFINITY;
1116 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1117 		if (p->cl_f == 0) {
1118 			cl->cl_cfmin = 0;
1119 			return;
1120 		}
1121 		if (p->cl_f < cfmin)
1122 			cfmin = p->cl_f;
1123 	}
1124 	cl->cl_cfmin = cfmin;
1125 }
1126 
1127 /*
1128  * TAILQ based ellist and actlist implementation
1129  * (ion wanted to make a calendar queue based implementation)
1130  */
1131 /*
1132  * eligible list holds backlogged classes being sorted by their eligible times.
1133  * there is one eligible list per interface.
1134  */
1135 
1136 static ellist_t *
1137 ellist_alloc(void)
1138 {
1139 	ellist_t *head;
1140 
1141 	head = kmalloc(sizeof(ellist_t *), M_ALTQ, M_WAITOK);
1142 	TAILQ_INIT(head);
1143 	return (head);
1144 }
1145 
1146 static void
1147 ellist_destroy(ellist_t *head)
1148 {
1149 	kfree(head, M_ALTQ);
1150 }
1151 
1152 static void
1153 ellist_insert(struct hfsc_class *cl)
1154 {
1155 	struct hfsc_if *hif = cl->cl_hif;
1156 	struct hfsc_class *p;
1157 
1158 	/* check the last entry first */
1159 	if ((p = TAILQ_LAST(hif->hif_eligible, _eligible)) == NULL ||
1160 	    p->cl_e <= cl->cl_e) {
1161 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1162 		return;
1163 	}
1164 
1165 	TAILQ_FOREACH(p, hif->hif_eligible, cl_ellist) {
1166 		if (cl->cl_e < p->cl_e) {
1167 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1168 			return;
1169 		}
1170 	}
1171 	KKASSERT(0); /* should not reach here */
1172 }
1173 
1174 static void
1175 ellist_remove(struct hfsc_class *cl)
1176 {
1177 	struct hfsc_if *hif = cl->cl_hif;
1178 
1179 	TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1180 }
1181 
1182 static void
1183 ellist_update(struct hfsc_class *cl)
1184 {
1185 	struct hfsc_if *hif = cl->cl_hif;
1186 	struct hfsc_class *p, *last;
1187 
1188 	/*
1189 	 * the eligible time of a class increases monotonically.
1190 	 * if the next entry has a larger eligible time, nothing to do.
1191 	 */
1192 	p = TAILQ_NEXT(cl, cl_ellist);
1193 	if (p == NULL || cl->cl_e <= p->cl_e)
1194 		return;
1195 
1196 	/* check the last entry */
1197 	last = TAILQ_LAST(hif->hif_eligible, _eligible);
1198 	KKASSERT(last != NULL);
1199 	if (last->cl_e <= cl->cl_e) {
1200 		TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1201 		TAILQ_INSERT_TAIL(hif->hif_eligible, cl, cl_ellist);
1202 		return;
1203 	}
1204 
1205 	/*
1206 	 * the new position must be between the next entry
1207 	 * and the last entry
1208 	 */
1209 	while ((p = TAILQ_NEXT(p, cl_ellist)) != NULL) {
1210 		if (cl->cl_e < p->cl_e) {
1211 			TAILQ_REMOVE(hif->hif_eligible, cl, cl_ellist);
1212 			TAILQ_INSERT_BEFORE(p, cl, cl_ellist);
1213 			return;
1214 		}
1215 	}
1216 	KKASSERT(0); /* should not reach here */
1217 }
1218 
1219 /* find the class with the minimum deadline among the eligible classes */
1220 struct hfsc_class *
1221 ellist_get_mindl(ellist_t *head, uint64_t cur_time)
1222 {
1223 	struct hfsc_class *p, *cl = NULL;
1224 
1225 	TAILQ_FOREACH(p, head, cl_ellist) {
1226 		if (p->cl_e > cur_time)
1227 			break;
1228 		if (cl == NULL || p->cl_d < cl->cl_d)
1229 			cl = p;
1230 	}
1231 	return (cl);
1232 }
1233 
1234 /*
1235  * active children list holds backlogged child classes being sorted
1236  * by their virtual time.
1237  * each intermediate class has one active children list.
1238  */
1239 static actlist_t *
1240 actlist_alloc(void)
1241 {
1242 	actlist_t *head;
1243 
1244 	head = kmalloc(sizeof(*head), M_ALTQ, M_WAITOK);
1245 	TAILQ_INIT(head);
1246 	return (head);
1247 }
1248 
1249 static void
1250 actlist_destroy(actlist_t *head)
1251 {
1252 	kfree(head, M_ALTQ);
1253 }
1254 static void
1255 actlist_insert(struct hfsc_class *cl)
1256 {
1257 	struct hfsc_class *p;
1258 
1259 	/* check the last entry first */
1260 	if ((p = TAILQ_LAST(cl->cl_parent->cl_actc, _active)) == NULL
1261 	    || p->cl_vt <= cl->cl_vt) {
1262 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1263 		return;
1264 	}
1265 
1266 	TAILQ_FOREACH(p, cl->cl_parent->cl_actc, cl_actlist) {
1267 		if (cl->cl_vt < p->cl_vt) {
1268 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1269 			return;
1270 		}
1271 	}
1272 	KKASSERT(0); /* should not reach here */
1273 }
1274 
1275 static void
1276 actlist_remove(struct hfsc_class *cl)
1277 {
1278 	TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1279 }
1280 
1281 static void
1282 actlist_update(struct hfsc_class *cl)
1283 {
1284 	struct hfsc_class *p, *last;
1285 
1286 	/*
1287 	 * the virtual time of a class increases monotonically during its
1288 	 * backlogged period.
1289 	 * if the next entry has a larger virtual time, nothing to do.
1290 	 */
1291 	p = TAILQ_NEXT(cl, cl_actlist);
1292 	if (p == NULL || cl->cl_vt < p->cl_vt)
1293 		return;
1294 
1295 	/* check the last entry */
1296 	last = TAILQ_LAST(cl->cl_parent->cl_actc, _active);
1297 	KKASSERT(last != NULL);
1298 	if (last->cl_vt <= cl->cl_vt) {
1299 		TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1300 		TAILQ_INSERT_TAIL(cl->cl_parent->cl_actc, cl, cl_actlist);
1301 		return;
1302 	}
1303 
1304 	/*
1305 	 * the new position must be between the next entry
1306 	 * and the last entry
1307 	 */
1308 	while ((p = TAILQ_NEXT(p, cl_actlist)) != NULL) {
1309 		if (cl->cl_vt < p->cl_vt) {
1310 			TAILQ_REMOVE(cl->cl_parent->cl_actc, cl, cl_actlist);
1311 			TAILQ_INSERT_BEFORE(p, cl, cl_actlist);
1312 			return;
1313 		}
1314 	}
1315 	KKASSERT(0); /* should not reach here */
1316 }
1317 
1318 static struct hfsc_class *
1319 actlist_firstfit(struct hfsc_class *cl, uint64_t cur_time)
1320 {
1321 	struct hfsc_class *p;
1322 
1323 	TAILQ_FOREACH(p, cl->cl_actc, cl_actlist) {
1324 		if (p->cl_f <= cur_time)
1325 			return (p);
1326 	}
1327 	return (NULL);
1328 }
1329 
1330 /*
1331  * service curve support functions
1332  *
1333  *  external service curve parameters
1334  *	m: bits/sec
1335  *	d: msec
1336  *  internal service curve parameters
1337  *	sm: (bytes/tsc_interval) << SM_SHIFT
1338  *	ism: (tsc_count/byte) << ISM_SHIFT
1339  *	dx: tsc_count
1340  *
1341  * SM_SHIFT and ISM_SHIFT are scaled in order to keep effective digits.
1342  * we should be able to handle 100K-1Gbps linkspeed with 200Hz-1GHz CPU
1343  * speed.  SM_SHIFT and ISM_SHIFT are selected to have at least 3 effective
1344  * digits in decimal using the following table.
1345  *
1346  *  bits/sec    100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
1347  *  ----------+-------------------------------------------------------
1348  *  bytes/nsec  12.5e-6    125e-6     1250e-6    12500e-6   125000e-6
1349  *  sm(500MHz)  25.0e-6    250e-6     2500e-6    25000e-6   250000e-6
1350  *  sm(200MHz)  62.5e-6    625e-6     6250e-6    62500e-6   625000e-6
1351  *
1352  *  nsec/byte   80000      8000       800        80         8
1353  *  ism(500MHz) 40000      4000       400        40         4
1354  *  ism(200MHz) 16000      1600       160        16         1.6
1355  */
1356 #define	SM_SHIFT	24
1357 #define	ISM_SHIFT	10
1358 
1359 #define	SM_MASK		((1LL << SM_SHIFT) - 1)
1360 #define	ISM_MASK	((1LL << ISM_SHIFT) - 1)
1361 
1362 static __inline uint64_t
1363 seg_x2y(uint64_t x, uint64_t sm)
1364 {
1365 	uint64_t y;
1366 
1367 	/*
1368 	 * compute
1369 	 *	y = x * sm >> SM_SHIFT
1370 	 * but divide it for the upper and lower bits to avoid overflow
1371 	 */
1372 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
1373 	return (y);
1374 }
1375 
1376 static __inline uint64_t
1377 seg_y2x(uint64_t y, uint64_t ism)
1378 {
1379 	uint64_t x;
1380 
1381 	if (y == 0)
1382 		x = 0;
1383 	else if (ism == HT_INFINITY)
1384 		x = HT_INFINITY;
1385 	else
1386 		x = (y >> ISM_SHIFT) * ism + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
1387 
1388 	return (x);
1389 }
1390 
1391 static __inline uint64_t
1392 m2sm(u_int m)
1393 {
1394 	uint64_t sm;
1395 
1396 	sm = ((uint64_t)m << SM_SHIFT) / 8 / machclk_freq;
1397 	return (sm);
1398 }
1399 
1400 static __inline uint64_t
1401 m2ism(u_int m)
1402 {
1403 	uint64_t ism;
1404 
1405 	if (m == 0)
1406 		ism = HT_INFINITY;
1407 	else
1408 		ism = ((uint64_t)machclk_freq << ISM_SHIFT) * 8 / m;
1409 	return (ism);
1410 }
1411 
1412 static __inline uint64_t
1413 d2dx(u_int d)
1414 {
1415 	uint64_t dx;
1416 
1417 	dx = ((uint64_t)d * machclk_freq) / 1000;
1418 	return (dx);
1419 }
1420 
1421 static u_int
1422 sm2m(uint64_t sm)
1423 {
1424 	uint64_t m;
1425 
1426 	m = (sm * 8 * machclk_freq) >> SM_SHIFT;
1427 	return ((u_int)m);
1428 }
1429 
1430 static u_int
1431 dx2d(uint64_t dx)
1432 {
1433 	uint64_t d;
1434 
1435 	d = dx * 1000 / machclk_freq;
1436 	return ((u_int)d);
1437 }
1438 
1439 static void
1440 sc2isc(struct service_curve *sc, struct internal_sc *isc)
1441 {
1442 	isc->sm1 = m2sm(sc->m1);
1443 	isc->ism1 = m2ism(sc->m1);
1444 	isc->dx = d2dx(sc->d);
1445 	isc->dy = seg_x2y(isc->dx, isc->sm1);
1446 	isc->sm2 = m2sm(sc->m2);
1447 	isc->ism2 = m2ism(sc->m2);
1448 }
1449 
1450 /*
1451  * initialize the runtime service curve with the given internal
1452  * service curve starting at (x, y).
1453  */
1454 static void
1455 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1456 {
1457 	rtsc->x = x;
1458 	rtsc->y = y;
1459 	rtsc->sm1 = isc->sm1;
1460 	rtsc->ism1 = isc->ism1;
1461 	rtsc->dx = isc->dx;
1462 	rtsc->dy = isc->dy;
1463 	rtsc->sm2 = isc->sm2;
1464 	rtsc->ism2 = isc->ism2;
1465 }
1466 
1467 /*
1468  * calculate the y-projection of the runtime service curve by the
1469  * given x-projection value
1470  */
1471 static uint64_t
1472 rtsc_y2x(struct runtime_sc *rtsc, uint64_t y)
1473 {
1474 	uint64_t x;
1475 
1476 	if (y < rtsc->y) {
1477 		x = rtsc->x;
1478 	} else if (y <= rtsc->y + rtsc->dy) {
1479 		/* x belongs to the 1st segment */
1480 		if (rtsc->dy == 0)
1481 			x = rtsc->x + rtsc->dx;
1482 		else
1483 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
1484 	} else {
1485 		/* x belongs to the 2nd segment */
1486 		x = rtsc->x + rtsc->dx
1487 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
1488 	}
1489 	return (x);
1490 }
1491 
1492 static uint64_t
1493 rtsc_x2y(struct runtime_sc *rtsc, uint64_t x)
1494 {
1495 	uint64_t y;
1496 
1497 	if (x <= rtsc->x) {
1498 		y = rtsc->y;
1499 	} else if (x <= rtsc->x + rtsc->dx) {
1500 		/* y belongs to the 1st segment */
1501 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
1502 	} else
1503 		/* y belongs to the 2nd segment */
1504 		y = rtsc->y + rtsc->dy
1505 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
1506 	return (y);
1507 }
1508 
1509 /*
1510  * update the runtime service curve by taking the minimum of the current
1511  * runtime service curve and the service curve starting at (x, y).
1512  */
1513 static void
1514 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, uint64_t x, uint64_t y)
1515 {
1516 	uint64_t y1, y2, dx, dy;
1517 
1518 	if (isc->sm1 <= isc->sm2) {
1519 		/* service curve is convex */
1520 		y1 = rtsc_x2y(rtsc, x);
1521 		if (y1 < y)
1522 			/* the current rtsc is smaller */
1523 			return;
1524 		rtsc->x = x;
1525 		rtsc->y = y;
1526 		return;
1527 	}
1528 
1529 	/*
1530 	 * service curve is concave
1531 	 * compute the two y values of the current rtsc
1532 	 *	y1: at x
1533 	 *	y2: at (x + dx)
1534 	 */
1535 	y1 = rtsc_x2y(rtsc, x);
1536 	if (y1 <= y) {
1537 		/* rtsc is below isc, no change to rtsc */
1538 		return;
1539 	}
1540 
1541 	y2 = rtsc_x2y(rtsc, x + isc->dx);
1542 	if (y2 >= y + isc->dy) {
1543 		/* rtsc is above isc, replace rtsc by isc */
1544 		rtsc->x = x;
1545 		rtsc->y = y;
1546 		rtsc->dx = isc->dx;
1547 		rtsc->dy = isc->dy;
1548 		return;
1549 	}
1550 
1551 	/*
1552 	 * the two curves intersect
1553 	 * compute the offsets (dx, dy) using the reverse
1554 	 * function of seg_x2y()
1555 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
1556 	 */
1557 	dx = ((y1 - y) << SM_SHIFT) / (isc->sm1 - isc->sm2);
1558 	/*
1559 	 * check if (x, y1) belongs to the 1st segment of rtsc.
1560 	 * if so, add the offset.
1561 	 */
1562 	if (rtsc->x + rtsc->dx > x)
1563 		dx += rtsc->x + rtsc->dx - x;
1564 	dy = seg_x2y(dx, isc->sm1);
1565 
1566 	rtsc->x = x;
1567 	rtsc->y = y;
1568 	rtsc->dx = dx;
1569 	rtsc->dy = dy;
1570 }
1571 
1572 static void
1573 get_class_stats(struct hfsc_classstats *sp, struct hfsc_class *cl)
1574 {
1575 	sp->class_id = cl->cl_id;
1576 	sp->class_handle = cl->cl_handle;
1577 
1578 	if (cl->cl_rsc != NULL) {
1579 		sp->rsc.m1 = sm2m(cl->cl_rsc->sm1);
1580 		sp->rsc.d = dx2d(cl->cl_rsc->dx);
1581 		sp->rsc.m2 = sm2m(cl->cl_rsc->sm2);
1582 	} else {
1583 		sp->rsc.m1 = 0;
1584 		sp->rsc.d = 0;
1585 		sp->rsc.m2 = 0;
1586 	}
1587 	if (cl->cl_fsc != NULL) {
1588 		sp->fsc.m1 = sm2m(cl->cl_fsc->sm1);
1589 		sp->fsc.d = dx2d(cl->cl_fsc->dx);
1590 		sp->fsc.m2 = sm2m(cl->cl_fsc->sm2);
1591 	} else {
1592 		sp->fsc.m1 = 0;
1593 		sp->fsc.d = 0;
1594 		sp->fsc.m2 = 0;
1595 	}
1596 	if (cl->cl_usc != NULL) {
1597 		sp->usc.m1 = sm2m(cl->cl_usc->sm1);
1598 		sp->usc.d = dx2d(cl->cl_usc->dx);
1599 		sp->usc.m2 = sm2m(cl->cl_usc->sm2);
1600 	} else {
1601 		sp->usc.m1 = 0;
1602 		sp->usc.d = 0;
1603 		sp->usc.m2 = 0;
1604 	}
1605 
1606 	sp->total = cl->cl_total;
1607 	sp->cumul = cl->cl_cumul;
1608 
1609 	sp->d = cl->cl_d;
1610 	sp->e = cl->cl_e;
1611 	sp->vt = cl->cl_vt;
1612 	sp->f = cl->cl_f;
1613 
1614 	sp->initvt = cl->cl_initvt;
1615 	sp->vtperiod = cl->cl_vtperiod;
1616 	sp->parentperiod = cl->cl_parentperiod;
1617 	sp->nactive = cl->cl_nactive;
1618 	sp->vtoff = cl->cl_vtoff;
1619 	sp->cvtmax = cl->cl_cvtmax;
1620 	sp->myf = cl->cl_myf;
1621 	sp->cfmin = cl->cl_cfmin;
1622 	sp->cvtmin = cl->cl_cvtmin;
1623 	sp->myfadj = cl->cl_myfadj;
1624 	sp->vtadj = cl->cl_vtadj;
1625 
1626 	sp->cur_time = read_machclk();
1627 	sp->machclk_freq = machclk_freq;
1628 
1629 	sp->qlength = qlen(cl->cl_q);
1630 	sp->qlimit = qlimit(cl->cl_q);
1631 	sp->xmit_cnt = cl->cl_stats.xmit_cnt;
1632 	sp->drop_cnt = cl->cl_stats.drop_cnt;
1633 	sp->period = cl->cl_stats.period;
1634 
1635 	sp->qtype = qtype(cl->cl_q);
1636 #ifdef ALTQ_RED
1637 	if (q_is_red(cl->cl_q))
1638 		red_getstats(cl->cl_red, &sp->red[0]);
1639 #endif
1640 #ifdef ALTQ_RIO
1641 	if (q_is_rio(cl->cl_q))
1642 		rio_getstats((rio_t *)cl->cl_red, &sp->red[0]);
1643 #endif
1644 }
1645 
1646 /* convert a class handle to the corresponding class pointer */
1647 static struct hfsc_class *
1648 clh_to_clp(struct hfsc_if *hif, uint32_t chandle)
1649 {
1650 	int i;
1651 	struct hfsc_class *cl;
1652 
1653 	if (chandle == 0)
1654 		return (NULL);
1655 	/*
1656 	 * first, try optimistically the slot matching the lower bits of
1657 	 * the handle.  if it fails, do the linear table search.
1658 	 */
1659 	i = chandle % HFSC_MAX_CLASSES;
1660 	if ((cl = hif->hif_class_tbl[i]) != NULL && cl->cl_handle == chandle)
1661 		return (cl);
1662 	for (i = 0; i < HFSC_MAX_CLASSES; i++)
1663 		if ((cl = hif->hif_class_tbl[i]) != NULL &&
1664 		    cl->cl_handle == chandle)
1665 			return (cl);
1666 	return (NULL);
1667 }
1668 
1669 #endif /* ALTQ_HFSC */
1670