1/*
2 * Copyright (c) 2003 Patrick McHardy, <kaber@trash.net>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
8 *
9 * 2003-10-17 - Ported from altq
10 */
11/*
12 * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
13 *
14 * Permission to use, copy, modify, and distribute this software and
15 * its documentation is hereby granted (including for commercial or
16 * for-profit use), provided that both the copyright notice and this
17 * permission notice appear in all copies of the software, derivative
18 * works, or modified versions, and any portions thereof.
19 *
20 * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
21 * WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON PROVIDES THIS
22 * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 * DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
28 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
32 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
33 * DAMAGE.
34 *
35 * Carnegie Mellon encourages (but does not require) users of this
36 * software to return any improvements or extensions that they make,
37 * and to grant Carnegie Mellon the rights to redistribute these
38 * changes without encumbrance.
39 */
40/*
41 * H-FSC is described in Proceedings of SIGCOMM'97,
42 * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing,
43 * Real-Time and Priority Service"
44 * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng.
45 *
46 * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing.
47 * when a class has an upperlimit, the fit-time is computed from the
48 * upperlimit service curve.  the link-sharing scheduler does not schedule
49 * a class whose fit-time exceeds the current time.
50 */
51
52#include <linux/kernel.h>
53#include <linux/module.h>
54#include <linux/types.h>
55#include <linux/errno.h>
56#include <linux/compiler.h>
57#include <linux/spinlock.h>
58#include <linux/skbuff.h>
59#include <linux/string.h>
60#include <linux/slab.h>
61#include <linux/list.h>
62#include <linux/rbtree.h>
63#include <linux/init.h>
64#include <linux/rtnetlink.h>
65#include <linux/pkt_sched.h>
66#include <net/netlink.h>
67#include <net/pkt_sched.h>
68#include <net/pkt_cls.h>
69#include <asm/div64.h>
70
71/*
72 * kernel internal service curve representation:
73 *   coordinates are given by 64 bit unsigned integers.
74 *   x-axis: unit is clock count.
75 *   y-axis: unit is byte.
76 *
77 *   The service curve parameters are converted to the internal
78 *   representation. The slope values are scaled to avoid overflow.
79 *   the inverse slope values as well as the y-projection of the 1st
80 *   segment are kept in order to avoid 64-bit divide operations
81 *   that are expensive on 32-bit architectures.
82 */
83
84struct internal_sc {
85	u64	sm1;	/* scaled slope of the 1st segment */
86	u64	ism1;	/* scaled inverse-slope of the 1st segment */
87	u64	dx;	/* the x-projection of the 1st segment */
88	u64	dy;	/* the y-projection of the 1st segment */
89	u64	sm2;	/* scaled slope of the 2nd segment */
90	u64	ism2;	/* scaled inverse-slope of the 2nd segment */
91};
92
93/* runtime service curve */
94struct runtime_sc {
95	u64	x;	/* current starting position on x-axis */
96	u64	y;	/* current starting position on y-axis */
97	u64	sm1;	/* scaled slope of the 1st segment */
98	u64	ism1;	/* scaled inverse-slope of the 1st segment */
99	u64	dx;	/* the x-projection of the 1st segment */
100	u64	dy;	/* the y-projection of the 1st segment */
101	u64	sm2;	/* scaled slope of the 2nd segment */
102	u64	ism2;	/* scaled inverse-slope of the 2nd segment */
103};
104
105enum hfsc_class_flags {
106	HFSC_RSC = 0x1,
107	HFSC_FSC = 0x2,
108	HFSC_USC = 0x4
109};
110
111struct hfsc_class {
112	struct Qdisc_class_common cl_common;
113
114	struct gnet_stats_basic_sync bstats;
115	struct gnet_stats_queue qstats;
116	struct net_rate_estimator __rcu *rate_est;
117	struct tcf_proto __rcu *filter_list; /* filter list */
118	struct tcf_block *block;
119	unsigned int	level;		/* class level in hierarchy */
120
121	struct hfsc_sched *sched;	/* scheduler data */
122	struct hfsc_class *cl_parent;	/* parent class */
123	struct list_head siblings;	/* sibling classes */
124	struct list_head children;	/* child classes */
125	struct Qdisc	*qdisc;		/* leaf qdisc */
126
127	struct rb_node el_node;		/* qdisc's eligible tree member */
128	struct rb_root vt_tree;		/* active children sorted by cl_vt */
129	struct rb_node vt_node;		/* parent's vt_tree member */
130	struct rb_root cf_tree;		/* active children sorted by cl_f */
131	struct rb_node cf_node;		/* parent's cf_heap member */
132
133	u64	cl_total;		/* total work in bytes */
134	u64	cl_cumul;		/* cumulative work in bytes done by
135					   real-time criteria */
136
137	u64	cl_d;			/* deadline*/
138	u64	cl_e;			/* eligible time */
139	u64	cl_vt;			/* virtual time */
140	u64	cl_f;			/* time when this class will fit for
141					   link-sharing, max(myf, cfmin) */
142	u64	cl_myf;			/* my fit-time (calculated from this
143					   class's own upperlimit curve) */
144	u64	cl_cfmin;		/* earliest children's fit-time (used
145					   with cl_myf to obtain cl_f) */
146	u64	cl_cvtmin;		/* minimal virtual time among the
147					   children fit for link-sharing
148					   (monotonic within a period) */
149	u64	cl_vtadj;		/* intra-period cumulative vt
150					   adjustment */
151	u64	cl_cvtoff;		/* largest virtual time seen among
152					   the children */
153
154	struct internal_sc cl_rsc;	/* internal real-time service curve */
155	struct internal_sc cl_fsc;	/* internal fair service curve */
156	struct internal_sc cl_usc;	/* internal upperlimit service curve */
157	struct runtime_sc cl_deadline;	/* deadline curve */
158	struct runtime_sc cl_eligible;	/* eligible curve */
159	struct runtime_sc cl_virtual;	/* virtual curve */
160	struct runtime_sc cl_ulimit;	/* upperlimit curve */
161
162	u8		cl_flags;	/* which curves are valid */
163	u32		cl_vtperiod;	/* vt period sequence number */
164	u32		cl_parentperiod;/* parent's vt period sequence number*/
165	u32		cl_nactive;	/* number of active children */
166};
167
168struct hfsc_sched {
169	u16	defcls;				/* default class id */
170	struct hfsc_class root;			/* root class */
171	struct Qdisc_class_hash clhash;		/* class hash */
172	struct rb_root eligible;		/* eligible tree */
173	struct qdisc_watchdog watchdog;		/* watchdog timer */
174};
175
176#define	HT_INFINITY	0xffffffffffffffffULL	/* infinite time value */
177
178
179/*
180 * eligible tree holds backlogged classes being sorted by their eligible times.
181 * there is one eligible tree per hfsc instance.
182 */
183
184static void
185eltree_insert(struct hfsc_class *cl)
186{
187	struct rb_node **p = &cl->sched->eligible.rb_node;
188	struct rb_node *parent = NULL;
189	struct hfsc_class *cl1;
190
191	while (*p != NULL) {
192		parent = *p;
193		cl1 = rb_entry(parent, struct hfsc_class, el_node);
194		if (cl->cl_e >= cl1->cl_e)
195			p = &parent->rb_right;
196		else
197			p = &parent->rb_left;
198	}
199	rb_link_node(&cl->el_node, parent, p);
200	rb_insert_color(&cl->el_node, &cl->sched->eligible);
201}
202
203static inline void
204eltree_remove(struct hfsc_class *cl)
205{
206	rb_erase(&cl->el_node, &cl->sched->eligible);
207}
208
209static inline void
210eltree_update(struct hfsc_class *cl)
211{
212	eltree_remove(cl);
213	eltree_insert(cl);
214}
215
216/* find the class with the minimum deadline among the eligible classes */
217static inline struct hfsc_class *
218eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
219{
220	struct hfsc_class *p, *cl = NULL;
221	struct rb_node *n;
222
223	for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
224		p = rb_entry(n, struct hfsc_class, el_node);
225		if (p->cl_e > cur_time)
226			break;
227		if (cl == NULL || p->cl_d < cl->cl_d)
228			cl = p;
229	}
230	return cl;
231}
232
233/* find the class with minimum eligible time among the eligible classes */
234static inline struct hfsc_class *
235eltree_get_minel(struct hfsc_sched *q)
236{
237	struct rb_node *n;
238
239	n = rb_first(&q->eligible);
240	if (n == NULL)
241		return NULL;
242	return rb_entry(n, struct hfsc_class, el_node);
243}
244
245/*
246 * vttree holds holds backlogged child classes being sorted by their virtual
247 * time. each intermediate class has one vttree.
248 */
249static void
250vttree_insert(struct hfsc_class *cl)
251{
252	struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
253	struct rb_node *parent = NULL;
254	struct hfsc_class *cl1;
255
256	while (*p != NULL) {
257		parent = *p;
258		cl1 = rb_entry(parent, struct hfsc_class, vt_node);
259		if (cl->cl_vt >= cl1->cl_vt)
260			p = &parent->rb_right;
261		else
262			p = &parent->rb_left;
263	}
264	rb_link_node(&cl->vt_node, parent, p);
265	rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
266}
267
268static inline void
269vttree_remove(struct hfsc_class *cl)
270{
271	rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
272}
273
274static inline void
275vttree_update(struct hfsc_class *cl)
276{
277	vttree_remove(cl);
278	vttree_insert(cl);
279}
280
281static inline struct hfsc_class *
282vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
283{
284	struct hfsc_class *p;
285	struct rb_node *n;
286
287	for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
288		p = rb_entry(n, struct hfsc_class, vt_node);
289		if (p->cl_f <= cur_time)
290			return p;
291	}
292	return NULL;
293}
294
295/*
296 * get the leaf class with the minimum vt in the hierarchy
297 */
298static struct hfsc_class *
299vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
300{
301	/* if root-class's cfmin is bigger than cur_time nothing to do */
302	if (cl->cl_cfmin > cur_time)
303		return NULL;
304
305	while (cl->level > 0) {
306		cl = vttree_firstfit(cl, cur_time);
307		if (cl == NULL)
308			return NULL;
309		/*
310		 * update parent's cl_cvtmin.
311		 */
312		if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
313			cl->cl_parent->cl_cvtmin = cl->cl_vt;
314	}
315	return cl;
316}
317
318static void
319cftree_insert(struct hfsc_class *cl)
320{
321	struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
322	struct rb_node *parent = NULL;
323	struct hfsc_class *cl1;
324
325	while (*p != NULL) {
326		parent = *p;
327		cl1 = rb_entry(parent, struct hfsc_class, cf_node);
328		if (cl->cl_f >= cl1->cl_f)
329			p = &parent->rb_right;
330		else
331			p = &parent->rb_left;
332	}
333	rb_link_node(&cl->cf_node, parent, p);
334	rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
335}
336
337static inline void
338cftree_remove(struct hfsc_class *cl)
339{
340	rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
341}
342
343static inline void
344cftree_update(struct hfsc_class *cl)
345{
346	cftree_remove(cl);
347	cftree_insert(cl);
348}
349
350/*
351 * service curve support functions
352 *
353 *  external service curve parameters
354 *	m: bps
355 *	d: us
356 *  internal service curve parameters
357 *	sm: (bytes/psched_us) << SM_SHIFT
358 *	ism: (psched_us/byte) << ISM_SHIFT
359 *	dx: psched_us
360 *
361 * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
362 *
363 * sm and ism are scaled in order to keep effective digits.
364 * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
365 * digits in decimal using the following table.
366 *
367 *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
368 *  ------------+-------------------------------------------------------
369 *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
370 *
371 *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
372 *
373 * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
374 */
375#define	SM_SHIFT	(30 - PSCHED_SHIFT)
376#define	ISM_SHIFT	(8 + PSCHED_SHIFT)
377
378#define	SM_MASK		((1ULL << SM_SHIFT) - 1)
379#define	ISM_MASK	((1ULL << ISM_SHIFT) - 1)
380
381static inline u64
382seg_x2y(u64 x, u64 sm)
383{
384	u64 y;
385
386	/*
387	 * compute
388	 *	y = x * sm >> SM_SHIFT
389	 * but divide it for the upper and lower bits to avoid overflow
390	 */
391	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
392	return y;
393}
394
395static inline u64
396seg_y2x(u64 y, u64 ism)
397{
398	u64 x;
399
400	if (y == 0)
401		x = 0;
402	else if (ism == HT_INFINITY)
403		x = HT_INFINITY;
404	else {
405		x = (y >> ISM_SHIFT) * ism
406		    + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
407	}
408	return x;
409}
410
411/* Convert m (bps) into sm (bytes/psched us) */
412static u64
413m2sm(u32 m)
414{
415	u64 sm;
416
417	sm = ((u64)m << SM_SHIFT);
418	sm += PSCHED_TICKS_PER_SEC - 1;
419	do_div(sm, PSCHED_TICKS_PER_SEC);
420	return sm;
421}
422
423/* convert m (bps) into ism (psched us/byte) */
424static u64
425m2ism(u32 m)
426{
427	u64 ism;
428
429	if (m == 0)
430		ism = HT_INFINITY;
431	else {
432		ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
433		ism += m - 1;
434		do_div(ism, m);
435	}
436	return ism;
437}
438
439/* convert d (us) into dx (psched us) */
440static u64
441d2dx(u32 d)
442{
443	u64 dx;
444
445	dx = ((u64)d * PSCHED_TICKS_PER_SEC);
446	dx += USEC_PER_SEC - 1;
447	do_div(dx, USEC_PER_SEC);
448	return dx;
449}
450
451/* convert sm (bytes/psched us) into m (bps) */
452static u32
453sm2m(u64 sm)
454{
455	u64 m;
456
457	m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
458	return (u32)m;
459}
460
461/* convert dx (psched us) into d (us) */
462static u32
463dx2d(u64 dx)
464{
465	u64 d;
466
467	d = dx * USEC_PER_SEC;
468	do_div(d, PSCHED_TICKS_PER_SEC);
469	return (u32)d;
470}
471
472static void
473sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
474{
475	isc->sm1  = m2sm(sc->m1);
476	isc->ism1 = m2ism(sc->m1);
477	isc->dx   = d2dx(sc->d);
478	isc->dy   = seg_x2y(isc->dx, isc->sm1);
479	isc->sm2  = m2sm(sc->m2);
480	isc->ism2 = m2ism(sc->m2);
481}
482
483/*
484 * initialize the runtime service curve with the given internal
485 * service curve starting at (x, y).
486 */
487static void
488rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
489{
490	rtsc->x	   = x;
491	rtsc->y    = y;
492	rtsc->sm1  = isc->sm1;
493	rtsc->ism1 = isc->ism1;
494	rtsc->dx   = isc->dx;
495	rtsc->dy   = isc->dy;
496	rtsc->sm2  = isc->sm2;
497	rtsc->ism2 = isc->ism2;
498}
499
500/*
501 * calculate the y-projection of the runtime service curve by the
502 * given x-projection value
503 */
504static u64
505rtsc_y2x(struct runtime_sc *rtsc, u64 y)
506{
507	u64 x;
508
509	if (y < rtsc->y)
510		x = rtsc->x;
511	else if (y <= rtsc->y + rtsc->dy) {
512		/* x belongs to the 1st segment */
513		if (rtsc->dy == 0)
514			x = rtsc->x + rtsc->dx;
515		else
516			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
517	} else {
518		/* x belongs to the 2nd segment */
519		x = rtsc->x + rtsc->dx
520		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
521	}
522	return x;
523}
524
525static u64
526rtsc_x2y(struct runtime_sc *rtsc, u64 x)
527{
528	u64 y;
529
530	if (x <= rtsc->x)
531		y = rtsc->y;
532	else if (x <= rtsc->x + rtsc->dx)
533		/* y belongs to the 1st segment */
534		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
535	else
536		/* y belongs to the 2nd segment */
537		y = rtsc->y + rtsc->dy
538		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
539	return y;
540}
541
542/*
543 * update the runtime service curve by taking the minimum of the current
544 * runtime service curve and the service curve starting at (x, y).
545 */
546static void
547rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
548{
549	u64 y1, y2, dx, dy;
550	u32 dsm;
551
552	if (isc->sm1 <= isc->sm2) {
553		/* service curve is convex */
554		y1 = rtsc_x2y(rtsc, x);
555		if (y1 < y)
556			/* the current rtsc is smaller */
557			return;
558		rtsc->x = x;
559		rtsc->y = y;
560		return;
561	}
562
563	/*
564	 * service curve is concave
565	 * compute the two y values of the current rtsc
566	 *	y1: at x
567	 *	y2: at (x + dx)
568	 */
569	y1 = rtsc_x2y(rtsc, x);
570	if (y1 <= y) {
571		/* rtsc is below isc, no change to rtsc */
572		return;
573	}
574
575	y2 = rtsc_x2y(rtsc, x + isc->dx);
576	if (y2 >= y + isc->dy) {
577		/* rtsc is above isc, replace rtsc by isc */
578		rtsc->x = x;
579		rtsc->y = y;
580		rtsc->dx = isc->dx;
581		rtsc->dy = isc->dy;
582		return;
583	}
584
585	/*
586	 * the two curves intersect
587	 * compute the offsets (dx, dy) using the reverse
588	 * function of seg_x2y()
589	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
590	 */
591	dx = (y1 - y) << SM_SHIFT;
592	dsm = isc->sm1 - isc->sm2;
593	do_div(dx, dsm);
594	/*
595	 * check if (x, y1) belongs to the 1st segment of rtsc.
596	 * if so, add the offset.
597	 */
598	if (rtsc->x + rtsc->dx > x)
599		dx += rtsc->x + rtsc->dx - x;
600	dy = seg_x2y(dx, isc->sm1);
601
602	rtsc->x = x;
603	rtsc->y = y;
604	rtsc->dx = dx;
605	rtsc->dy = dy;
606}
607
608static void
609init_ed(struct hfsc_class *cl, unsigned int next_len)
610{
611	u64 cur_time = psched_get_time();
612
613	/* update the deadline curve */
614	rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
615
616	/*
617	 * update the eligible curve.
618	 * for concave, it is equal to the deadline curve.
619	 * for convex, it is a linear curve with slope m2.
620	 */
621	cl->cl_eligible = cl->cl_deadline;
622	if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
623		cl->cl_eligible.dx = 0;
624		cl->cl_eligible.dy = 0;
625	}
626
627	/* compute e and d */
628	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
629	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
630
631	eltree_insert(cl);
632}
633
634static void
635update_ed(struct hfsc_class *cl, unsigned int next_len)
636{
637	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
638	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
639
640	eltree_update(cl);
641}
642
643static inline void
644update_d(struct hfsc_class *cl, unsigned int next_len)
645{
646	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
647}
648
649static inline void
650update_cfmin(struct hfsc_class *cl)
651{
652	struct rb_node *n = rb_first(&cl->cf_tree);
653	struct hfsc_class *p;
654
655	if (n == NULL) {
656		cl->cl_cfmin = 0;
657		return;
658	}
659	p = rb_entry(n, struct hfsc_class, cf_node);
660	cl->cl_cfmin = p->cl_f;
661}
662
663static void
664init_vf(struct hfsc_class *cl, unsigned int len)
665{
666	struct hfsc_class *max_cl;
667	struct rb_node *n;
668	u64 vt, f, cur_time;
669	int go_active;
670
671	cur_time = 0;
672	go_active = 1;
673	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
674		if (go_active && cl->cl_nactive++ == 0)
675			go_active = 1;
676		else
677			go_active = 0;
678
679		if (go_active) {
680			n = rb_last(&cl->cl_parent->vt_tree);
681			if (n != NULL) {
682				max_cl = rb_entry(n, struct hfsc_class, vt_node);
683				/*
684				 * set vt to the average of the min and max
685				 * classes.  if the parent's period didn't
686				 * change, don't decrease vt of the class.
687				 */
688				vt = max_cl->cl_vt;
689				if (cl->cl_parent->cl_cvtmin != 0)
690					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
691
692				if (cl->cl_parent->cl_vtperiod !=
693				    cl->cl_parentperiod || vt > cl->cl_vt)
694					cl->cl_vt = vt;
695			} else {
696				/*
697				 * first child for a new parent backlog period.
698				 * initialize cl_vt to the highest value seen
699				 * among the siblings. this is analogous to
700				 * what cur_time would provide in realtime case.
701				 */
702				cl->cl_vt = cl->cl_parent->cl_cvtoff;
703				cl->cl_parent->cl_cvtmin = 0;
704			}
705
706			/* update the virtual curve */
707			rtsc_min(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
708			cl->cl_vtadj = 0;
709
710			cl->cl_vtperiod++;  /* increment vt period */
711			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
712			if (cl->cl_parent->cl_nactive == 0)
713				cl->cl_parentperiod++;
714			cl->cl_f = 0;
715
716			vttree_insert(cl);
717			cftree_insert(cl);
718
719			if (cl->cl_flags & HFSC_USC) {
720				/* class has upper limit curve */
721				if (cur_time == 0)
722					cur_time = psched_get_time();
723
724				/* update the ulimit curve */
725				rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
726					 cl->cl_total);
727				/* compute myf */
728				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
729						      cl->cl_total);
730			}
731		}
732
733		f = max(cl->cl_myf, cl->cl_cfmin);
734		if (f != cl->cl_f) {
735			cl->cl_f = f;
736			cftree_update(cl);
737		}
738		update_cfmin(cl->cl_parent);
739	}
740}
741
742static void
743update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
744{
745	u64 f; /* , myf_bound, delta; */
746	int go_passive = 0;
747
748	if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
749		go_passive = 1;
750
751	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
752		cl->cl_total += len;
753
754		if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
755			continue;
756
757		if (go_passive && --cl->cl_nactive == 0)
758			go_passive = 1;
759		else
760			go_passive = 0;
761
762		/* update vt */
763		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) + cl->cl_vtadj;
764
765		/*
766		 * if vt of the class is smaller than cvtmin,
767		 * the class was skipped in the past due to non-fit.
768		 * if so, we need to adjust vtadj.
769		 */
770		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
771			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
772			cl->cl_vt = cl->cl_parent->cl_cvtmin;
773		}
774
775		if (go_passive) {
776			/* no more active child, going passive */
777
778			/* update cvtoff of the parent class */
779			if (cl->cl_vt > cl->cl_parent->cl_cvtoff)
780				cl->cl_parent->cl_cvtoff = cl->cl_vt;
781
782			/* remove this class from the vt tree */
783			vttree_remove(cl);
784
785			cftree_remove(cl);
786			update_cfmin(cl->cl_parent);
787
788			continue;
789		}
790
791		/* update the vt tree */
792		vttree_update(cl);
793
794		/* update f */
795		if (cl->cl_flags & HFSC_USC) {
796			cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
797#if 0
798			cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
799							      cl->cl_total);
800			/*
801			 * This code causes classes to stay way under their
802			 * limit when multiple classes are used at gigabit
803			 * speed. needs investigation. -kaber
804			 */
805			/*
806			 * if myf lags behind by more than one clock tick
807			 * from the current time, adjust myfadj to prevent
808			 * a rate-limited class from going greedy.
809			 * in a steady state under rate-limiting, myf
810			 * fluctuates within one clock tick.
811			 */
812			myf_bound = cur_time - PSCHED_JIFFIE2US(1);
813			if (cl->cl_myf < myf_bound) {
814				delta = cur_time - cl->cl_myf;
815				cl->cl_myfadj += delta;
816				cl->cl_myf += delta;
817			}
818#endif
819		}
820
821		f = max(cl->cl_myf, cl->cl_cfmin);
822		if (f != cl->cl_f) {
823			cl->cl_f = f;
824			cftree_update(cl);
825			update_cfmin(cl->cl_parent);
826		}
827	}
828}
829
830static unsigned int
831qdisc_peek_len(struct Qdisc *sch)
832{
833	struct sk_buff *skb;
834	unsigned int len;
835
836	skb = sch->ops->peek(sch);
837	if (unlikely(skb == NULL)) {
838		qdisc_warn_nonwc("qdisc_peek_len", sch);
839		return 0;
840	}
841	len = qdisc_pkt_len(skb);
842
843	return len;
844}
845
846static void
847hfsc_adjust_levels(struct hfsc_class *cl)
848{
849	struct hfsc_class *p;
850	unsigned int level;
851
852	do {
853		level = 0;
854		list_for_each_entry(p, &cl->children, siblings) {
855			if (p->level >= level)
856				level = p->level + 1;
857		}
858		cl->level = level;
859	} while ((cl = cl->cl_parent) != NULL);
860}
861
862static inline struct hfsc_class *
863hfsc_find_class(u32 classid, struct Qdisc *sch)
864{
865	struct hfsc_sched *q = qdisc_priv(sch);
866	struct Qdisc_class_common *clc;
867
868	clc = qdisc_class_find(&q->clhash, classid);
869	if (clc == NULL)
870		return NULL;
871	return container_of(clc, struct hfsc_class, cl_common);
872}
873
874static void
875hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
876		u64 cur_time)
877{
878	sc2isc(rsc, &cl->cl_rsc);
879	rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
880	cl->cl_eligible = cl->cl_deadline;
881	if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
882		cl->cl_eligible.dx = 0;
883		cl->cl_eligible.dy = 0;
884	}
885	cl->cl_flags |= HFSC_RSC;
886}
887
888static void
889hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
890{
891	sc2isc(fsc, &cl->cl_fsc);
892	rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
893	cl->cl_flags |= HFSC_FSC;
894}
895
896static void
897hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
898		u64 cur_time)
899{
900	sc2isc(usc, &cl->cl_usc);
901	rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
902	cl->cl_flags |= HFSC_USC;
903}
904
905static void
906hfsc_upgrade_rt(struct hfsc_class *cl)
907{
908	cl->cl_fsc = cl->cl_rsc;
909	rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
910	cl->cl_flags |= HFSC_FSC;
911}
912
913static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
914	[TCA_HFSC_RSC]	= { .len = sizeof(struct tc_service_curve) },
915	[TCA_HFSC_FSC]	= { .len = sizeof(struct tc_service_curve) },
916	[TCA_HFSC_USC]	= { .len = sizeof(struct tc_service_curve) },
917};
918
919static int
920hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
921		  struct nlattr **tca, unsigned long *arg,
922		  struct netlink_ext_ack *extack)
923{
924	struct hfsc_sched *q = qdisc_priv(sch);
925	struct hfsc_class *cl = (struct hfsc_class *)*arg;
926	struct hfsc_class *parent = NULL;
927	struct nlattr *opt = tca[TCA_OPTIONS];
928	struct nlattr *tb[TCA_HFSC_MAX + 1];
929	struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
930	u64 cur_time;
931	int err;
932
933	if (opt == NULL)
934		return -EINVAL;
935
936	err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
937					  NULL);
938	if (err < 0)
939		return err;
940
941	if (tb[TCA_HFSC_RSC]) {
942		rsc = nla_data(tb[TCA_HFSC_RSC]);
943		if (rsc->m1 == 0 && rsc->m2 == 0)
944			rsc = NULL;
945	}
946
947	if (tb[TCA_HFSC_FSC]) {
948		fsc = nla_data(tb[TCA_HFSC_FSC]);
949		if (fsc->m1 == 0 && fsc->m2 == 0)
950			fsc = NULL;
951	}
952
953	if (tb[TCA_HFSC_USC]) {
954		usc = nla_data(tb[TCA_HFSC_USC]);
955		if (usc->m1 == 0 && usc->m2 == 0)
956			usc = NULL;
957	}
958
959	if (cl != NULL) {
960		int old_flags;
961
962		if (parentid) {
963			if (cl->cl_parent &&
964			    cl->cl_parent->cl_common.classid != parentid)
965				return -EINVAL;
966			if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
967				return -EINVAL;
968		}
969		cur_time = psched_get_time();
970
971		if (tca[TCA_RATE]) {
972			err = gen_replace_estimator(&cl->bstats, NULL,
973						    &cl->rate_est,
974						    NULL,
975						    true,
976						    tca[TCA_RATE]);
977			if (err)
978				return err;
979		}
980
981		sch_tree_lock(sch);
982		old_flags = cl->cl_flags;
983
984		if (rsc != NULL)
985			hfsc_change_rsc(cl, rsc, cur_time);
986		if (fsc != NULL)
987			hfsc_change_fsc(cl, fsc);
988		if (usc != NULL)
989			hfsc_change_usc(cl, usc, cur_time);
990
991		if (cl->qdisc->q.qlen != 0) {
992			int len = qdisc_peek_len(cl->qdisc);
993
994			if (cl->cl_flags & HFSC_RSC) {
995				if (old_flags & HFSC_RSC)
996					update_ed(cl, len);
997				else
998					init_ed(cl, len);
999			}
1000
1001			if (cl->cl_flags & HFSC_FSC) {
1002				if (old_flags & HFSC_FSC)
1003					update_vf(cl, 0, cur_time);
1004				else
1005					init_vf(cl, len);
1006			}
1007		}
1008		sch_tree_unlock(sch);
1009
1010		return 0;
1011	}
1012
1013	if (parentid == TC_H_ROOT)
1014		return -EEXIST;
1015
1016	parent = &q->root;
1017	if (parentid) {
1018		parent = hfsc_find_class(parentid, sch);
1019		if (parent == NULL)
1020			return -ENOENT;
1021	}
1022
1023	if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1024		return -EINVAL;
1025	if (hfsc_find_class(classid, sch))
1026		return -EEXIST;
1027
1028	if (rsc == NULL && fsc == NULL)
1029		return -EINVAL;
1030
1031	cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1032	if (cl == NULL)
1033		return -ENOBUFS;
1034
1035	err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1036	if (err) {
1037		kfree(cl);
1038		return err;
1039	}
1040
1041	if (tca[TCA_RATE]) {
1042		err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1043					NULL, true, tca[TCA_RATE]);
1044		if (err) {
1045			tcf_block_put(cl->block);
1046			kfree(cl);
1047			return err;
1048		}
1049	}
1050
1051	if (rsc != NULL)
1052		hfsc_change_rsc(cl, rsc, 0);
1053	if (fsc != NULL)
1054		hfsc_change_fsc(cl, fsc);
1055	if (usc != NULL)
1056		hfsc_change_usc(cl, usc, 0);
1057
1058	cl->cl_common.classid = classid;
1059	cl->sched     = q;
1060	cl->cl_parent = parent;
1061	cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1062				      classid, NULL);
1063	if (cl->qdisc == NULL)
1064		cl->qdisc = &noop_qdisc;
1065	else
1066		qdisc_hash_add(cl->qdisc, true);
1067	INIT_LIST_HEAD(&cl->children);
1068	cl->vt_tree = RB_ROOT;
1069	cl->cf_tree = RB_ROOT;
1070
1071	sch_tree_lock(sch);
1072	/* Check if the inner class is a misconfigured 'rt' */
1073	if (!(parent->cl_flags & HFSC_FSC) && parent != &q->root) {
1074		NL_SET_ERR_MSG(extack,
1075			       "Forced curve change on parent 'rt' to 'sc'");
1076		hfsc_upgrade_rt(parent);
1077	}
1078	qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1079	list_add_tail(&cl->siblings, &parent->children);
1080	if (parent->level == 0)
1081		qdisc_purge_queue(parent->qdisc);
1082	hfsc_adjust_levels(parent);
1083	sch_tree_unlock(sch);
1084
1085	qdisc_class_hash_grow(sch, &q->clhash);
1086
1087	*arg = (unsigned long)cl;
1088	return 0;
1089}
1090
1091static void
1092hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1093{
1094	struct hfsc_sched *q = qdisc_priv(sch);
1095
1096	tcf_block_put(cl->block);
1097	qdisc_put(cl->qdisc);
1098	gen_kill_estimator(&cl->rate_est);
1099	if (cl != &q->root)
1100		kfree(cl);
1101}
1102
1103static int
1104hfsc_delete_class(struct Qdisc *sch, unsigned long arg,
1105		  struct netlink_ext_ack *extack)
1106{
1107	struct hfsc_sched *q = qdisc_priv(sch);
1108	struct hfsc_class *cl = (struct hfsc_class *)arg;
1109
1110	if (cl->level > 0 || qdisc_class_in_use(&cl->cl_common) ||
1111	    cl == &q->root) {
1112		NL_SET_ERR_MSG(extack, "HFSC class in use");
1113		return -EBUSY;
1114	}
1115
1116	sch_tree_lock(sch);
1117
1118	list_del(&cl->siblings);
1119	hfsc_adjust_levels(cl->cl_parent);
1120
1121	qdisc_purge_queue(cl->qdisc);
1122	qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1123
1124	sch_tree_unlock(sch);
1125
1126	hfsc_destroy_class(sch, cl);
1127	return 0;
1128}
1129
1130static struct hfsc_class *
1131hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1132{
1133	struct hfsc_sched *q = qdisc_priv(sch);
1134	struct hfsc_class *head, *cl;
1135	struct tcf_result res;
1136	struct tcf_proto *tcf;
1137	int result;
1138
1139	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1140	    (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1141		if (cl->level == 0)
1142			return cl;
1143
1144	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1145	head = &q->root;
1146	tcf = rcu_dereference_bh(q->root.filter_list);
1147	while (tcf && (result = tcf_classify(skb, NULL, tcf, &res, false)) >= 0) {
1148#ifdef CONFIG_NET_CLS_ACT
1149		switch (result) {
1150		case TC_ACT_QUEUED:
1151		case TC_ACT_STOLEN:
1152		case TC_ACT_TRAP:
1153			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1154			fallthrough;
1155		case TC_ACT_SHOT:
1156			return NULL;
1157		}
1158#endif
1159		cl = (struct hfsc_class *)res.class;
1160		if (!cl) {
1161			cl = hfsc_find_class(res.classid, sch);
1162			if (!cl)
1163				break; /* filter selected invalid classid */
1164			if (cl->level >= head->level)
1165				break; /* filter may only point downwards */
1166		}
1167
1168		if (cl->level == 0)
1169			return cl; /* hit leaf class */
1170
1171		/* apply inner filter chain */
1172		tcf = rcu_dereference_bh(cl->filter_list);
1173		head = cl;
1174	}
1175
1176	/* classification failed, try default class */
1177	cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1178	if (cl == NULL || cl->level > 0)
1179		return NULL;
1180
1181	return cl;
1182}
1183
1184static int
1185hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1186		 struct Qdisc **old, struct netlink_ext_ack *extack)
1187{
1188	struct hfsc_class *cl = (struct hfsc_class *)arg;
1189
1190	if (cl->level > 0)
1191		return -EINVAL;
1192	if (new == NULL) {
1193		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1194					cl->cl_common.classid, NULL);
1195		if (new == NULL)
1196			new = &noop_qdisc;
1197	}
1198
1199	*old = qdisc_replace(sch, new, &cl->qdisc);
1200	return 0;
1201}
1202
1203static struct Qdisc *
1204hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1205{
1206	struct hfsc_class *cl = (struct hfsc_class *)arg;
1207
1208	if (cl->level == 0)
1209		return cl->qdisc;
1210
1211	return NULL;
1212}
1213
1214static void
1215hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1216{
1217	struct hfsc_class *cl = (struct hfsc_class *)arg;
1218
1219	/* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
1220	 * needs to be called explicitly to remove a class from vttree.
1221	 */
1222	update_vf(cl, 0, 0);
1223	if (cl->cl_flags & HFSC_RSC)
1224		eltree_remove(cl);
1225}
1226
1227static unsigned long
1228hfsc_search_class(struct Qdisc *sch, u32 classid)
1229{
1230	return (unsigned long)hfsc_find_class(classid, sch);
1231}
1232
1233static unsigned long
1234hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1235{
1236	struct hfsc_class *p = (struct hfsc_class *)parent;
1237	struct hfsc_class *cl = hfsc_find_class(classid, sch);
1238
1239	if (cl != NULL) {
1240		if (p != NULL && p->level <= cl->level)
1241			return 0;
1242		qdisc_class_get(&cl->cl_common);
1243	}
1244
1245	return (unsigned long)cl;
1246}
1247
1248static void
1249hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1250{
1251	struct hfsc_class *cl = (struct hfsc_class *)arg;
1252
1253	qdisc_class_put(&cl->cl_common);
1254}
1255
1256static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
1257					struct netlink_ext_ack *extack)
1258{
1259	struct hfsc_sched *q = qdisc_priv(sch);
1260	struct hfsc_class *cl = (struct hfsc_class *)arg;
1261
1262	if (cl == NULL)
1263		cl = &q->root;
1264
1265	return cl->block;
1266}
1267
1268static int
1269hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1270{
1271	struct tc_service_curve tsc;
1272
1273	tsc.m1 = sm2m(sc->sm1);
1274	tsc.d  = dx2d(sc->dx);
1275	tsc.m2 = sm2m(sc->sm2);
1276	if (nla_put(skb, attr, sizeof(tsc), &tsc))
1277		goto nla_put_failure;
1278
1279	return skb->len;
1280
1281 nla_put_failure:
1282	return -1;
1283}
1284
1285static int
1286hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1287{
1288	if ((cl->cl_flags & HFSC_RSC) &&
1289	    (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1290		goto nla_put_failure;
1291
1292	if ((cl->cl_flags & HFSC_FSC) &&
1293	    (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1294		goto nla_put_failure;
1295
1296	if ((cl->cl_flags & HFSC_USC) &&
1297	    (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1298		goto nla_put_failure;
1299
1300	return skb->len;
1301
1302 nla_put_failure:
1303	return -1;
1304}
1305
1306static int
1307hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1308		struct tcmsg *tcm)
1309{
1310	struct hfsc_class *cl = (struct hfsc_class *)arg;
1311	struct nlattr *nest;
1312
1313	tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1314					  TC_H_ROOT;
1315	tcm->tcm_handle = cl->cl_common.classid;
1316	if (cl->level == 0)
1317		tcm->tcm_info = cl->qdisc->handle;
1318
1319	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1320	if (nest == NULL)
1321		goto nla_put_failure;
1322	if (hfsc_dump_curves(skb, cl) < 0)
1323		goto nla_put_failure;
1324	return nla_nest_end(skb, nest);
1325
1326 nla_put_failure:
1327	nla_nest_cancel(skb, nest);
1328	return -EMSGSIZE;
1329}
1330
1331static int
1332hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1333	struct gnet_dump *d)
1334{
1335	struct hfsc_class *cl = (struct hfsc_class *)arg;
1336	struct tc_hfsc_stats xstats;
1337	__u32 qlen;
1338
1339	qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
1340	xstats.level   = cl->level;
1341	xstats.period  = cl->cl_vtperiod;
1342	xstats.work    = cl->cl_total;
1343	xstats.rtwork  = cl->cl_cumul;
1344
1345	if (gnet_stats_copy_basic(d, NULL, &cl->bstats, true) < 0 ||
1346	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1347	    gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1348		return -1;
1349
1350	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1351}
1352
1353
1354
1355static void
1356hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1357{
1358	struct hfsc_sched *q = qdisc_priv(sch);
1359	struct hfsc_class *cl;
1360	unsigned int i;
1361
1362	if (arg->stop)
1363		return;
1364
1365	for (i = 0; i < q->clhash.hashsize; i++) {
1366		hlist_for_each_entry(cl, &q->clhash.hash[i],
1367				     cl_common.hnode) {
1368			if (!tc_qdisc_stats_dump(sch, (unsigned long)cl, arg))
1369				return;
1370		}
1371	}
1372}
1373
1374static void
1375hfsc_schedule_watchdog(struct Qdisc *sch)
1376{
1377	struct hfsc_sched *q = qdisc_priv(sch);
1378	struct hfsc_class *cl;
1379	u64 next_time = 0;
1380
1381	cl = eltree_get_minel(q);
1382	if (cl)
1383		next_time = cl->cl_e;
1384	if (q->root.cl_cfmin != 0) {
1385		if (next_time == 0 || next_time > q->root.cl_cfmin)
1386			next_time = q->root.cl_cfmin;
1387	}
1388	if (next_time)
1389		qdisc_watchdog_schedule(&q->watchdog, next_time);
1390}
1391
1392static int
1393hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
1394		struct netlink_ext_ack *extack)
1395{
1396	struct hfsc_sched *q = qdisc_priv(sch);
1397	struct tc_hfsc_qopt *qopt;
1398	int err;
1399
1400	qdisc_watchdog_init(&q->watchdog, sch);
1401
1402	if (!opt || nla_len(opt) < sizeof(*qopt))
1403		return -EINVAL;
1404	qopt = nla_data(opt);
1405
1406	q->defcls = qopt->defcls;
1407	err = qdisc_class_hash_init(&q->clhash);
1408	if (err < 0)
1409		return err;
1410	q->eligible = RB_ROOT;
1411
1412	err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
1413	if (err)
1414		return err;
1415
1416	gnet_stats_basic_sync_init(&q->root.bstats);
1417	q->root.cl_common.classid = sch->handle;
1418	q->root.sched   = q;
1419	q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1420					  sch->handle, NULL);
1421	if (q->root.qdisc == NULL)
1422		q->root.qdisc = &noop_qdisc;
1423	else
1424		qdisc_hash_add(q->root.qdisc, true);
1425	INIT_LIST_HEAD(&q->root.children);
1426	q->root.vt_tree = RB_ROOT;
1427	q->root.cf_tree = RB_ROOT;
1428
1429	qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1430	qdisc_class_hash_grow(sch, &q->clhash);
1431
1432	return 0;
1433}
1434
1435static int
1436hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
1437		  struct netlink_ext_ack *extack)
1438{
1439	struct hfsc_sched *q = qdisc_priv(sch);
1440	struct tc_hfsc_qopt *qopt;
1441
1442	if (nla_len(opt) < sizeof(*qopt))
1443		return -EINVAL;
1444	qopt = nla_data(opt);
1445
1446	sch_tree_lock(sch);
1447	q->defcls = qopt->defcls;
1448	sch_tree_unlock(sch);
1449
1450	return 0;
1451}
1452
1453static void
1454hfsc_reset_class(struct hfsc_class *cl)
1455{
1456	cl->cl_total        = 0;
1457	cl->cl_cumul        = 0;
1458	cl->cl_d            = 0;
1459	cl->cl_e            = 0;
1460	cl->cl_vt           = 0;
1461	cl->cl_vtadj        = 0;
1462	cl->cl_cvtmin       = 0;
1463	cl->cl_cvtoff       = 0;
1464	cl->cl_vtperiod     = 0;
1465	cl->cl_parentperiod = 0;
1466	cl->cl_f            = 0;
1467	cl->cl_myf          = 0;
1468	cl->cl_cfmin        = 0;
1469	cl->cl_nactive      = 0;
1470
1471	cl->vt_tree = RB_ROOT;
1472	cl->cf_tree = RB_ROOT;
1473	qdisc_reset(cl->qdisc);
1474
1475	if (cl->cl_flags & HFSC_RSC)
1476		rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1477	if (cl->cl_flags & HFSC_FSC)
1478		rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1479	if (cl->cl_flags & HFSC_USC)
1480		rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1481}
1482
1483static void
1484hfsc_reset_qdisc(struct Qdisc *sch)
1485{
1486	struct hfsc_sched *q = qdisc_priv(sch);
1487	struct hfsc_class *cl;
1488	unsigned int i;
1489
1490	for (i = 0; i < q->clhash.hashsize; i++) {
1491		hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1492			hfsc_reset_class(cl);
1493	}
1494	q->eligible = RB_ROOT;
1495	qdisc_watchdog_cancel(&q->watchdog);
1496}
1497
1498static void
1499hfsc_destroy_qdisc(struct Qdisc *sch)
1500{
1501	struct hfsc_sched *q = qdisc_priv(sch);
1502	struct hlist_node *next;
1503	struct hfsc_class *cl;
1504	unsigned int i;
1505
1506	for (i = 0; i < q->clhash.hashsize; i++) {
1507		hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
1508			tcf_block_put(cl->block);
1509			cl->block = NULL;
1510		}
1511	}
1512	for (i = 0; i < q->clhash.hashsize; i++) {
1513		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1514					  cl_common.hnode)
1515			hfsc_destroy_class(sch, cl);
1516	}
1517	qdisc_class_hash_destroy(&q->clhash);
1518	qdisc_watchdog_cancel(&q->watchdog);
1519}
1520
1521static int
1522hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1523{
1524	struct hfsc_sched *q = qdisc_priv(sch);
1525	unsigned char *b = skb_tail_pointer(skb);
1526	struct tc_hfsc_qopt qopt;
1527
1528	qopt.defcls = q->defcls;
1529	if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1530		goto nla_put_failure;
1531	return skb->len;
1532
1533 nla_put_failure:
1534	nlmsg_trim(skb, b);
1535	return -1;
1536}
1537
1538static int
1539hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
1540{
1541	unsigned int len = qdisc_pkt_len(skb);
1542	struct hfsc_class *cl;
1543	int err;
1544	bool first;
1545
1546	cl = hfsc_classify(skb, sch, &err);
1547	if (cl == NULL) {
1548		if (err & __NET_XMIT_BYPASS)
1549			qdisc_qstats_drop(sch);
1550		__qdisc_drop(skb, to_free);
1551		return err;
1552	}
1553
1554	first = !cl->qdisc->q.qlen;
1555	err = qdisc_enqueue(skb, cl->qdisc, to_free);
1556	if (unlikely(err != NET_XMIT_SUCCESS)) {
1557		if (net_xmit_drop_count(err)) {
1558			cl->qstats.drops++;
1559			qdisc_qstats_drop(sch);
1560		}
1561		return err;
1562	}
1563
1564	if (first) {
1565		if (cl->cl_flags & HFSC_RSC)
1566			init_ed(cl, len);
1567		if (cl->cl_flags & HFSC_FSC)
1568			init_vf(cl, len);
1569		/*
1570		 * If this is the first packet, isolate the head so an eventual
1571		 * head drop before the first dequeue operation has no chance
1572		 * to invalidate the deadline.
1573		 */
1574		if (cl->cl_flags & HFSC_RSC)
1575			cl->qdisc->ops->peek(cl->qdisc);
1576
1577	}
1578
1579	sch->qstats.backlog += len;
1580	sch->q.qlen++;
1581
1582	return NET_XMIT_SUCCESS;
1583}
1584
1585static struct sk_buff *
1586hfsc_dequeue(struct Qdisc *sch)
1587{
1588	struct hfsc_sched *q = qdisc_priv(sch);
1589	struct hfsc_class *cl;
1590	struct sk_buff *skb;
1591	u64 cur_time;
1592	unsigned int next_len;
1593	int realtime = 0;
1594
1595	if (sch->q.qlen == 0)
1596		return NULL;
1597
1598	cur_time = psched_get_time();
1599
1600	/*
1601	 * if there are eligible classes, use real-time criteria.
1602	 * find the class with the minimum deadline among
1603	 * the eligible classes.
1604	 */
1605	cl = eltree_get_mindl(q, cur_time);
1606	if (cl) {
1607		realtime = 1;
1608	} else {
1609		/*
1610		 * use link-sharing criteria
1611		 * get the class with the minimum vt in the hierarchy
1612		 */
1613		cl = vttree_get_minvt(&q->root, cur_time);
1614		if (cl == NULL) {
1615			qdisc_qstats_overlimit(sch);
1616			hfsc_schedule_watchdog(sch);
1617			return NULL;
1618		}
1619	}
1620
1621	skb = qdisc_dequeue_peeked(cl->qdisc);
1622	if (skb == NULL) {
1623		qdisc_warn_nonwc("HFSC", cl->qdisc);
1624		return NULL;
1625	}
1626
1627	bstats_update(&cl->bstats, skb);
1628	update_vf(cl, qdisc_pkt_len(skb), cur_time);
1629	if (realtime)
1630		cl->cl_cumul += qdisc_pkt_len(skb);
1631
1632	if (cl->cl_flags & HFSC_RSC) {
1633		if (cl->qdisc->q.qlen != 0) {
1634			/* update ed */
1635			next_len = qdisc_peek_len(cl->qdisc);
1636			if (realtime)
1637				update_ed(cl, next_len);
1638			else
1639				update_d(cl, next_len);
1640		} else {
1641			/* the class becomes passive */
1642			eltree_remove(cl);
1643		}
1644	}
1645
1646	qdisc_bstats_update(sch, skb);
1647	qdisc_qstats_backlog_dec(sch, skb);
1648	sch->q.qlen--;
1649
1650	return skb;
1651}
1652
1653static const struct Qdisc_class_ops hfsc_class_ops = {
1654	.change		= hfsc_change_class,
1655	.delete		= hfsc_delete_class,
1656	.graft		= hfsc_graft_class,
1657	.leaf		= hfsc_class_leaf,
1658	.qlen_notify	= hfsc_qlen_notify,
1659	.find		= hfsc_search_class,
1660	.bind_tcf	= hfsc_bind_tcf,
1661	.unbind_tcf	= hfsc_unbind_tcf,
1662	.tcf_block	= hfsc_tcf_block,
1663	.dump		= hfsc_dump_class,
1664	.dump_stats	= hfsc_dump_class_stats,
1665	.walk		= hfsc_walk
1666};
1667
1668static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1669	.id		= "hfsc",
1670	.init		= hfsc_init_qdisc,
1671	.change		= hfsc_change_qdisc,
1672	.reset		= hfsc_reset_qdisc,
1673	.destroy	= hfsc_destroy_qdisc,
1674	.dump		= hfsc_dump_qdisc,
1675	.enqueue	= hfsc_enqueue,
1676	.dequeue	= hfsc_dequeue,
1677	.peek		= qdisc_peek_dequeued,
1678	.cl_ops		= &hfsc_class_ops,
1679	.priv_size	= sizeof(struct hfsc_sched),
1680	.owner		= THIS_MODULE
1681};
1682MODULE_ALIAS_NET_SCH("hfsc");
1683
1684static int __init
1685hfsc_init(void)
1686{
1687	return register_qdisc(&hfsc_qdisc_ops);
1688}
1689
1690static void __exit
1691hfsc_cleanup(void)
1692{
1693	unregister_qdisc(&hfsc_qdisc_ops);
1694}
1695
1696MODULE_LICENSE("GPL");
1697MODULE_DESCRIPTION("Hierarchical Fair Service Curve scheduler");
1698module_init(hfsc_init);
1699module_exit(hfsc_cleanup);
1700