xref: /kernel/linux/linux-5.10/net/sched/sch_hfsc.c (revision 8c2ecf20)
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_packed 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	filter_cnt;	/* filter count */
120	unsigned int	level;		/* class level in hierarchy */
121
122	struct hfsc_sched *sched;	/* scheduler data */
123	struct hfsc_class *cl_parent;	/* parent class */
124	struct list_head siblings;	/* sibling classes */
125	struct list_head children;	/* child classes */
126	struct Qdisc	*qdisc;		/* leaf qdisc */
127
128	struct rb_node el_node;		/* qdisc's eligible tree member */
129	struct rb_root vt_tree;		/* active children sorted by cl_vt */
130	struct rb_node vt_node;		/* parent's vt_tree member */
131	struct rb_root cf_tree;		/* active children sorted by cl_f */
132	struct rb_node cf_node;		/* parent's cf_heap member */
133
134	u64	cl_total;		/* total work in bytes */
135	u64	cl_cumul;		/* cumulative work in bytes done by
136					   real-time criteria */
137
138	u64	cl_d;			/* deadline*/
139	u64	cl_e;			/* eligible time */
140	u64	cl_vt;			/* virtual time */
141	u64	cl_f;			/* time when this class will fit for
142					   link-sharing, max(myf, cfmin) */
143	u64	cl_myf;			/* my fit-time (calculated from this
144					   class's own upperlimit curve) */
145	u64	cl_cfmin;		/* earliest children's fit-time (used
146					   with cl_myf to obtain cl_f) */
147	u64	cl_cvtmin;		/* minimal virtual time among the
148					   children fit for link-sharing
149					   (monotonic within a period) */
150	u64	cl_vtadj;		/* intra-period cumulative vt
151					   adjustment */
152	u64	cl_cvtoff;		/* largest virtual time seen among
153					   the children */
154
155	struct internal_sc cl_rsc;	/* internal real-time service curve */
156	struct internal_sc cl_fsc;	/* internal fair service curve */
157	struct internal_sc cl_usc;	/* internal upperlimit service curve */
158	struct runtime_sc cl_deadline;	/* deadline curve */
159	struct runtime_sc cl_eligible;	/* eligible curve */
160	struct runtime_sc cl_virtual;	/* virtual curve */
161	struct runtime_sc cl_ulimit;	/* upperlimit curve */
162
163	u8		cl_flags;	/* which curves are valid */
164	u32		cl_vtperiod;	/* vt period sequence number */
165	u32		cl_parentperiod;/* parent's vt period sequence number*/
166	u32		cl_nactive;	/* number of active children */
167};
168
169struct hfsc_sched {
170	u16	defcls;				/* default class id */
171	struct hfsc_class root;			/* root class */
172	struct Qdisc_class_hash clhash;		/* class hash */
173	struct rb_root eligible;		/* eligible tree */
174	struct qdisc_watchdog watchdog;		/* watchdog timer */
175};
176
177#define	HT_INFINITY	0xffffffffffffffffULL	/* infinite time value */
178
179
180/*
181 * eligible tree holds backlogged classes being sorted by their eligible times.
182 * there is one eligible tree per hfsc instance.
183 */
184
185static void
186eltree_insert(struct hfsc_class *cl)
187{
188	struct rb_node **p = &cl->sched->eligible.rb_node;
189	struct rb_node *parent = NULL;
190	struct hfsc_class *cl1;
191
192	while (*p != NULL) {
193		parent = *p;
194		cl1 = rb_entry(parent, struct hfsc_class, el_node);
195		if (cl->cl_e >= cl1->cl_e)
196			p = &parent->rb_right;
197		else
198			p = &parent->rb_left;
199	}
200	rb_link_node(&cl->el_node, parent, p);
201	rb_insert_color(&cl->el_node, &cl->sched->eligible);
202}
203
204static inline void
205eltree_remove(struct hfsc_class *cl)
206{
207	rb_erase(&cl->el_node, &cl->sched->eligible);
208}
209
210static inline void
211eltree_update(struct hfsc_class *cl)
212{
213	eltree_remove(cl);
214	eltree_insert(cl);
215}
216
217/* find the class with the minimum deadline among the eligible classes */
218static inline struct hfsc_class *
219eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
220{
221	struct hfsc_class *p, *cl = NULL;
222	struct rb_node *n;
223
224	for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
225		p = rb_entry(n, struct hfsc_class, el_node);
226		if (p->cl_e > cur_time)
227			break;
228		if (cl == NULL || p->cl_d < cl->cl_d)
229			cl = p;
230	}
231	return cl;
232}
233
234/* find the class with minimum eligible time among the eligible classes */
235static inline struct hfsc_class *
236eltree_get_minel(struct hfsc_sched *q)
237{
238	struct rb_node *n;
239
240	n = rb_first(&q->eligible);
241	if (n == NULL)
242		return NULL;
243	return rb_entry(n, struct hfsc_class, el_node);
244}
245
246/*
247 * vttree holds holds backlogged child classes being sorted by their virtual
248 * time. each intermediate class has one vttree.
249 */
250static void
251vttree_insert(struct hfsc_class *cl)
252{
253	struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
254	struct rb_node *parent = NULL;
255	struct hfsc_class *cl1;
256
257	while (*p != NULL) {
258		parent = *p;
259		cl1 = rb_entry(parent, struct hfsc_class, vt_node);
260		if (cl->cl_vt >= cl1->cl_vt)
261			p = &parent->rb_right;
262		else
263			p = &parent->rb_left;
264	}
265	rb_link_node(&cl->vt_node, parent, p);
266	rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
267}
268
269static inline void
270vttree_remove(struct hfsc_class *cl)
271{
272	rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
273}
274
275static inline void
276vttree_update(struct hfsc_class *cl)
277{
278	vttree_remove(cl);
279	vttree_insert(cl);
280}
281
282static inline struct hfsc_class *
283vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
284{
285	struct hfsc_class *p;
286	struct rb_node *n;
287
288	for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
289		p = rb_entry(n, struct hfsc_class, vt_node);
290		if (p->cl_f <= cur_time)
291			return p;
292	}
293	return NULL;
294}
295
296/*
297 * get the leaf class with the minimum vt in the hierarchy
298 */
299static struct hfsc_class *
300vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
301{
302	/* if root-class's cfmin is bigger than cur_time nothing to do */
303	if (cl->cl_cfmin > cur_time)
304		return NULL;
305
306	while (cl->level > 0) {
307		cl = vttree_firstfit(cl, cur_time);
308		if (cl == NULL)
309			return NULL;
310		/*
311		 * update parent's cl_cvtmin.
312		 */
313		if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
314			cl->cl_parent->cl_cvtmin = cl->cl_vt;
315	}
316	return cl;
317}
318
319static void
320cftree_insert(struct hfsc_class *cl)
321{
322	struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
323	struct rb_node *parent = NULL;
324	struct hfsc_class *cl1;
325
326	while (*p != NULL) {
327		parent = *p;
328		cl1 = rb_entry(parent, struct hfsc_class, cf_node);
329		if (cl->cl_f >= cl1->cl_f)
330			p = &parent->rb_right;
331		else
332			p = &parent->rb_left;
333	}
334	rb_link_node(&cl->cf_node, parent, p);
335	rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
336}
337
338static inline void
339cftree_remove(struct hfsc_class *cl)
340{
341	rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
342}
343
344static inline void
345cftree_update(struct hfsc_class *cl)
346{
347	cftree_remove(cl);
348	cftree_insert(cl);
349}
350
351/*
352 * service curve support functions
353 *
354 *  external service curve parameters
355 *	m: bps
356 *	d: us
357 *  internal service curve parameters
358 *	sm: (bytes/psched_us) << SM_SHIFT
359 *	ism: (psched_us/byte) << ISM_SHIFT
360 *	dx: psched_us
361 *
362 * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
363 *
364 * sm and ism are scaled in order to keep effective digits.
365 * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
366 * digits in decimal using the following table.
367 *
368 *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
369 *  ------------+-------------------------------------------------------
370 *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
371 *
372 *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
373 *
374 * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
375 */
376#define	SM_SHIFT	(30 - PSCHED_SHIFT)
377#define	ISM_SHIFT	(8 + PSCHED_SHIFT)
378
379#define	SM_MASK		((1ULL << SM_SHIFT) - 1)
380#define	ISM_MASK	((1ULL << ISM_SHIFT) - 1)
381
382static inline u64
383seg_x2y(u64 x, u64 sm)
384{
385	u64 y;
386
387	/*
388	 * compute
389	 *	y = x * sm >> SM_SHIFT
390	 * but divide it for the upper and lower bits to avoid overflow
391	 */
392	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
393	return y;
394}
395
396static inline u64
397seg_y2x(u64 y, u64 ism)
398{
399	u64 x;
400
401	if (y == 0)
402		x = 0;
403	else if (ism == HT_INFINITY)
404		x = HT_INFINITY;
405	else {
406		x = (y >> ISM_SHIFT) * ism
407		    + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
408	}
409	return x;
410}
411
412/* Convert m (bps) into sm (bytes/psched us) */
413static u64
414m2sm(u32 m)
415{
416	u64 sm;
417
418	sm = ((u64)m << SM_SHIFT);
419	sm += PSCHED_TICKS_PER_SEC - 1;
420	do_div(sm, PSCHED_TICKS_PER_SEC);
421	return sm;
422}
423
424/* convert m (bps) into ism (psched us/byte) */
425static u64
426m2ism(u32 m)
427{
428	u64 ism;
429
430	if (m == 0)
431		ism = HT_INFINITY;
432	else {
433		ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
434		ism += m - 1;
435		do_div(ism, m);
436	}
437	return ism;
438}
439
440/* convert d (us) into dx (psched us) */
441static u64
442d2dx(u32 d)
443{
444	u64 dx;
445
446	dx = ((u64)d * PSCHED_TICKS_PER_SEC);
447	dx += USEC_PER_SEC - 1;
448	do_div(dx, USEC_PER_SEC);
449	return dx;
450}
451
452/* convert sm (bytes/psched us) into m (bps) */
453static u32
454sm2m(u64 sm)
455{
456	u64 m;
457
458	m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
459	return (u32)m;
460}
461
462/* convert dx (psched us) into d (us) */
463static u32
464dx2d(u64 dx)
465{
466	u64 d;
467
468	d = dx * USEC_PER_SEC;
469	do_div(d, PSCHED_TICKS_PER_SEC);
470	return (u32)d;
471}
472
473static void
474sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
475{
476	isc->sm1  = m2sm(sc->m1);
477	isc->ism1 = m2ism(sc->m1);
478	isc->dx   = d2dx(sc->d);
479	isc->dy   = seg_x2y(isc->dx, isc->sm1);
480	isc->sm2  = m2sm(sc->m2);
481	isc->ism2 = m2ism(sc->m2);
482}
483
484/*
485 * initialize the runtime service curve with the given internal
486 * service curve starting at (x, y).
487 */
488static void
489rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
490{
491	rtsc->x	   = x;
492	rtsc->y    = y;
493	rtsc->sm1  = isc->sm1;
494	rtsc->ism1 = isc->ism1;
495	rtsc->dx   = isc->dx;
496	rtsc->dy   = isc->dy;
497	rtsc->sm2  = isc->sm2;
498	rtsc->ism2 = isc->ism2;
499}
500
501/*
502 * calculate the y-projection of the runtime service curve by the
503 * given x-projection value
504 */
505static u64
506rtsc_y2x(struct runtime_sc *rtsc, u64 y)
507{
508	u64 x;
509
510	if (y < rtsc->y)
511		x = rtsc->x;
512	else if (y <= rtsc->y + rtsc->dy) {
513		/* x belongs to the 1st segment */
514		if (rtsc->dy == 0)
515			x = rtsc->x + rtsc->dx;
516		else
517			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
518	} else {
519		/* x belongs to the 2nd segment */
520		x = rtsc->x + rtsc->dx
521		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
522	}
523	return x;
524}
525
526static u64
527rtsc_x2y(struct runtime_sc *rtsc, u64 x)
528{
529	u64 y;
530
531	if (x <= rtsc->x)
532		y = rtsc->y;
533	else if (x <= rtsc->x + rtsc->dx)
534		/* y belongs to the 1st segment */
535		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
536	else
537		/* y belongs to the 2nd segment */
538		y = rtsc->y + rtsc->dy
539		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
540	return y;
541}
542
543/*
544 * update the runtime service curve by taking the minimum of the current
545 * runtime service curve and the service curve starting at (x, y).
546 */
547static void
548rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
549{
550	u64 y1, y2, dx, dy;
551	u32 dsm;
552
553	if (isc->sm1 <= isc->sm2) {
554		/* service curve is convex */
555		y1 = rtsc_x2y(rtsc, x);
556		if (y1 < y)
557			/* the current rtsc is smaller */
558			return;
559		rtsc->x = x;
560		rtsc->y = y;
561		return;
562	}
563
564	/*
565	 * service curve is concave
566	 * compute the two y values of the current rtsc
567	 *	y1: at x
568	 *	y2: at (x + dx)
569	 */
570	y1 = rtsc_x2y(rtsc, x);
571	if (y1 <= y) {
572		/* rtsc is below isc, no change to rtsc */
573		return;
574	}
575
576	y2 = rtsc_x2y(rtsc, x + isc->dx);
577	if (y2 >= y + isc->dy) {
578		/* rtsc is above isc, replace rtsc by isc */
579		rtsc->x = x;
580		rtsc->y = y;
581		rtsc->dx = isc->dx;
582		rtsc->dy = isc->dy;
583		return;
584	}
585
586	/*
587	 * the two curves intersect
588	 * compute the offsets (dx, dy) using the reverse
589	 * function of seg_x2y()
590	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
591	 */
592	dx = (y1 - y) << SM_SHIFT;
593	dsm = isc->sm1 - isc->sm2;
594	do_div(dx, dsm);
595	/*
596	 * check if (x, y1) belongs to the 1st segment of rtsc.
597	 * if so, add the offset.
598	 */
599	if (rtsc->x + rtsc->dx > x)
600		dx += rtsc->x + rtsc->dx - x;
601	dy = seg_x2y(dx, isc->sm1);
602
603	rtsc->x = x;
604	rtsc->y = y;
605	rtsc->dx = dx;
606	rtsc->dy = dy;
607}
608
609static void
610init_ed(struct hfsc_class *cl, unsigned int next_len)
611{
612	u64 cur_time = psched_get_time();
613
614	/* update the deadline curve */
615	rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
616
617	/*
618	 * update the eligible curve.
619	 * for concave, it is equal to the deadline curve.
620	 * for convex, it is a linear curve with slope m2.
621	 */
622	cl->cl_eligible = cl->cl_deadline;
623	if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
624		cl->cl_eligible.dx = 0;
625		cl->cl_eligible.dy = 0;
626	}
627
628	/* compute e and d */
629	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
630	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
631
632	eltree_insert(cl);
633}
634
635static void
636update_ed(struct hfsc_class *cl, unsigned int next_len)
637{
638	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
639	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
640
641	eltree_update(cl);
642}
643
644static inline void
645update_d(struct hfsc_class *cl, unsigned int next_len)
646{
647	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
648}
649
650static inline void
651update_cfmin(struct hfsc_class *cl)
652{
653	struct rb_node *n = rb_first(&cl->cf_tree);
654	struct hfsc_class *p;
655
656	if (n == NULL) {
657		cl->cl_cfmin = 0;
658		return;
659	}
660	p = rb_entry(n, struct hfsc_class, cf_node);
661	cl->cl_cfmin = p->cl_f;
662}
663
664static void
665init_vf(struct hfsc_class *cl, unsigned int len)
666{
667	struct hfsc_class *max_cl;
668	struct rb_node *n;
669	u64 vt, f, cur_time;
670	int go_active;
671
672	cur_time = 0;
673	go_active = 1;
674	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
675		if (go_active && cl->cl_nactive++ == 0)
676			go_active = 1;
677		else
678			go_active = 0;
679
680		if (go_active) {
681			n = rb_last(&cl->cl_parent->vt_tree);
682			if (n != NULL) {
683				max_cl = rb_entry(n, struct hfsc_class, vt_node);
684				/*
685				 * set vt to the average of the min and max
686				 * classes.  if the parent's period didn't
687				 * change, don't decrease vt of the class.
688				 */
689				vt = max_cl->cl_vt;
690				if (cl->cl_parent->cl_cvtmin != 0)
691					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
692
693				if (cl->cl_parent->cl_vtperiod !=
694				    cl->cl_parentperiod || vt > cl->cl_vt)
695					cl->cl_vt = vt;
696			} else {
697				/*
698				 * first child for a new parent backlog period.
699				 * initialize cl_vt to the highest value seen
700				 * among the siblings. this is analogous to
701				 * what cur_time would provide in realtime case.
702				 */
703				cl->cl_vt = cl->cl_parent->cl_cvtoff;
704				cl->cl_parent->cl_cvtmin = 0;
705			}
706
707			/* update the virtual curve */
708			rtsc_min(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
709			cl->cl_vtadj = 0;
710
711			cl->cl_vtperiod++;  /* increment vt period */
712			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
713			if (cl->cl_parent->cl_nactive == 0)
714				cl->cl_parentperiod++;
715			cl->cl_f = 0;
716
717			vttree_insert(cl);
718			cftree_insert(cl);
719
720			if (cl->cl_flags & HFSC_USC) {
721				/* class has upper limit curve */
722				if (cur_time == 0)
723					cur_time = psched_get_time();
724
725				/* update the ulimit curve */
726				rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
727					 cl->cl_total);
728				/* compute myf */
729				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
730						      cl->cl_total);
731			}
732		}
733
734		f = max(cl->cl_myf, cl->cl_cfmin);
735		if (f != cl->cl_f) {
736			cl->cl_f = f;
737			cftree_update(cl);
738		}
739		update_cfmin(cl->cl_parent);
740	}
741}
742
743static void
744update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
745{
746	u64 f; /* , myf_bound, delta; */
747	int go_passive = 0;
748
749	if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
750		go_passive = 1;
751
752	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
753		cl->cl_total += len;
754
755		if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
756			continue;
757
758		if (go_passive && --cl->cl_nactive == 0)
759			go_passive = 1;
760		else
761			go_passive = 0;
762
763		/* update vt */
764		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) + cl->cl_vtadj;
765
766		/*
767		 * if vt of the class is smaller than cvtmin,
768		 * the class was skipped in the past due to non-fit.
769		 * if so, we need to adjust vtadj.
770		 */
771		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
772			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
773			cl->cl_vt = cl->cl_parent->cl_cvtmin;
774		}
775
776		if (go_passive) {
777			/* no more active child, going passive */
778
779			/* update cvtoff of the parent class */
780			if (cl->cl_vt > cl->cl_parent->cl_cvtoff)
781				cl->cl_parent->cl_cvtoff = cl->cl_vt;
782
783			/* remove this class from the vt tree */
784			vttree_remove(cl);
785
786			cftree_remove(cl);
787			update_cfmin(cl->cl_parent);
788
789			continue;
790		}
791
792		/* update the vt tree */
793		vttree_update(cl);
794
795		/* update f */
796		if (cl->cl_flags & HFSC_USC) {
797			cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
798#if 0
799			cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
800							      cl->cl_total);
801			/*
802			 * This code causes classes to stay way under their
803			 * limit when multiple classes are used at gigabit
804			 * speed. needs investigation. -kaber
805			 */
806			/*
807			 * if myf lags behind by more than one clock tick
808			 * from the current time, adjust myfadj to prevent
809			 * a rate-limited class from going greedy.
810			 * in a steady state under rate-limiting, myf
811			 * fluctuates within one clock tick.
812			 */
813			myf_bound = cur_time - PSCHED_JIFFIE2US(1);
814			if (cl->cl_myf < myf_bound) {
815				delta = cur_time - cl->cl_myf;
816				cl->cl_myfadj += delta;
817				cl->cl_myf += delta;
818			}
819#endif
820		}
821
822		f = max(cl->cl_myf, cl->cl_cfmin);
823		if (f != cl->cl_f) {
824			cl->cl_f = f;
825			cftree_update(cl);
826			update_cfmin(cl->cl_parent);
827		}
828	}
829}
830
831static unsigned int
832qdisc_peek_len(struct Qdisc *sch)
833{
834	struct sk_buff *skb;
835	unsigned int len;
836
837	skb = sch->ops->peek(sch);
838	if (unlikely(skb == NULL)) {
839		qdisc_warn_nonwc("qdisc_peek_len", sch);
840		return 0;
841	}
842	len = qdisc_pkt_len(skb);
843
844	return len;
845}
846
847static void
848hfsc_adjust_levels(struct hfsc_class *cl)
849{
850	struct hfsc_class *p;
851	unsigned int level;
852
853	do {
854		level = 0;
855		list_for_each_entry(p, &cl->children, siblings) {
856			if (p->level >= level)
857				level = p->level + 1;
858		}
859		cl->level = level;
860	} while ((cl = cl->cl_parent) != NULL);
861}
862
863static inline struct hfsc_class *
864hfsc_find_class(u32 classid, struct Qdisc *sch)
865{
866	struct hfsc_sched *q = qdisc_priv(sch);
867	struct Qdisc_class_common *clc;
868
869	clc = qdisc_class_find(&q->clhash, classid);
870	if (clc == NULL)
871		return NULL;
872	return container_of(clc, struct hfsc_class, cl_common);
873}
874
875static void
876hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
877		u64 cur_time)
878{
879	sc2isc(rsc, &cl->cl_rsc);
880	rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
881	cl->cl_eligible = cl->cl_deadline;
882	if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
883		cl->cl_eligible.dx = 0;
884		cl->cl_eligible.dy = 0;
885	}
886	cl->cl_flags |= HFSC_RSC;
887}
888
889static void
890hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
891{
892	sc2isc(fsc, &cl->cl_fsc);
893	rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
894	cl->cl_flags |= HFSC_FSC;
895}
896
897static void
898hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
899		u64 cur_time)
900{
901	sc2isc(usc, &cl->cl_usc);
902	rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
903	cl->cl_flags |= HFSC_USC;
904}
905
906static void
907hfsc_upgrade_rt(struct hfsc_class *cl)
908{
909	cl->cl_fsc = cl->cl_rsc;
910	rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
911	cl->cl_flags |= HFSC_FSC;
912}
913
914static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
915	[TCA_HFSC_RSC]	= { .len = sizeof(struct tc_service_curve) },
916	[TCA_HFSC_FSC]	= { .len = sizeof(struct tc_service_curve) },
917	[TCA_HFSC_USC]	= { .len = sizeof(struct tc_service_curve) },
918};
919
920static int
921hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
922		  struct nlattr **tca, unsigned long *arg,
923		  struct netlink_ext_ack *extack)
924{
925	struct hfsc_sched *q = qdisc_priv(sch);
926	struct hfsc_class *cl = (struct hfsc_class *)*arg;
927	struct hfsc_class *parent = NULL;
928	struct nlattr *opt = tca[TCA_OPTIONS];
929	struct nlattr *tb[TCA_HFSC_MAX + 1];
930	struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
931	u64 cur_time;
932	int err;
933
934	if (opt == NULL)
935		return -EINVAL;
936
937	err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
938					  NULL);
939	if (err < 0)
940		return err;
941
942	if (tb[TCA_HFSC_RSC]) {
943		rsc = nla_data(tb[TCA_HFSC_RSC]);
944		if (rsc->m1 == 0 && rsc->m2 == 0)
945			rsc = NULL;
946	}
947
948	if (tb[TCA_HFSC_FSC]) {
949		fsc = nla_data(tb[TCA_HFSC_FSC]);
950		if (fsc->m1 == 0 && fsc->m2 == 0)
951			fsc = NULL;
952	}
953
954	if (tb[TCA_HFSC_USC]) {
955		usc = nla_data(tb[TCA_HFSC_USC]);
956		if (usc->m1 == 0 && usc->m2 == 0)
957			usc = NULL;
958	}
959
960	if (cl != NULL) {
961		int old_flags;
962
963		if (parentid) {
964			if (cl->cl_parent &&
965			    cl->cl_parent->cl_common.classid != parentid)
966				return -EINVAL;
967			if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
968				return -EINVAL;
969		}
970		cur_time = psched_get_time();
971
972		if (tca[TCA_RATE]) {
973			err = gen_replace_estimator(&cl->bstats, NULL,
974						    &cl->rate_est,
975						    NULL,
976						    qdisc_root_sleeping_running(sch),
977						    tca[TCA_RATE]);
978			if (err)
979				return err;
980		}
981
982		sch_tree_lock(sch);
983		old_flags = cl->cl_flags;
984
985		if (rsc != NULL)
986			hfsc_change_rsc(cl, rsc, cur_time);
987		if (fsc != NULL)
988			hfsc_change_fsc(cl, fsc);
989		if (usc != NULL)
990			hfsc_change_usc(cl, usc, cur_time);
991
992		if (cl->qdisc->q.qlen != 0) {
993			int len = qdisc_peek_len(cl->qdisc);
994
995			if (cl->cl_flags & HFSC_RSC) {
996				if (old_flags & HFSC_RSC)
997					update_ed(cl, len);
998				else
999					init_ed(cl, len);
1000			}
1001
1002			if (cl->cl_flags & HFSC_FSC) {
1003				if (old_flags & HFSC_FSC)
1004					update_vf(cl, 0, cur_time);
1005				else
1006					init_vf(cl, len);
1007			}
1008		}
1009		sch_tree_unlock(sch);
1010
1011		return 0;
1012	}
1013
1014	if (parentid == TC_H_ROOT)
1015		return -EEXIST;
1016
1017	parent = &q->root;
1018	if (parentid) {
1019		parent = hfsc_find_class(parentid, sch);
1020		if (parent == NULL)
1021			return -ENOENT;
1022	}
1023
1024	if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1025		return -EINVAL;
1026	if (hfsc_find_class(classid, sch))
1027		return -EEXIST;
1028
1029	if (rsc == NULL && fsc == NULL)
1030		return -EINVAL;
1031
1032	cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1033	if (cl == NULL)
1034		return -ENOBUFS;
1035
1036	err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1037	if (err) {
1038		kfree(cl);
1039		return err;
1040	}
1041
1042	if (tca[TCA_RATE]) {
1043		err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1044					NULL,
1045					qdisc_root_sleeping_running(sch),
1046					tca[TCA_RATE]);
1047		if (err) {
1048			tcf_block_put(cl->block);
1049			kfree(cl);
1050			return err;
1051		}
1052	}
1053
1054	if (rsc != NULL)
1055		hfsc_change_rsc(cl, rsc, 0);
1056	if (fsc != NULL)
1057		hfsc_change_fsc(cl, fsc);
1058	if (usc != NULL)
1059		hfsc_change_usc(cl, usc, 0);
1060
1061	cl->cl_common.classid = classid;
1062	cl->sched     = q;
1063	cl->cl_parent = parent;
1064	cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1065				      classid, NULL);
1066	if (cl->qdisc == NULL)
1067		cl->qdisc = &noop_qdisc;
1068	else
1069		qdisc_hash_add(cl->qdisc, true);
1070	INIT_LIST_HEAD(&cl->children);
1071	cl->vt_tree = RB_ROOT;
1072	cl->cf_tree = RB_ROOT;
1073
1074	sch_tree_lock(sch);
1075	/* Check if the inner class is a misconfigured 'rt' */
1076	if (!(parent->cl_flags & HFSC_FSC) && parent != &q->root) {
1077		NL_SET_ERR_MSG(extack,
1078			       "Forced curve change on parent 'rt' to 'sc'");
1079		hfsc_upgrade_rt(parent);
1080	}
1081	qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1082	list_add_tail(&cl->siblings, &parent->children);
1083	if (parent->level == 0)
1084		qdisc_purge_queue(parent->qdisc);
1085	hfsc_adjust_levels(parent);
1086	sch_tree_unlock(sch);
1087
1088	qdisc_class_hash_grow(sch, &q->clhash);
1089
1090	*arg = (unsigned long)cl;
1091	return 0;
1092}
1093
1094static void
1095hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1096{
1097	struct hfsc_sched *q = qdisc_priv(sch);
1098
1099	tcf_block_put(cl->block);
1100	qdisc_put(cl->qdisc);
1101	gen_kill_estimator(&cl->rate_est);
1102	if (cl != &q->root)
1103		kfree(cl);
1104}
1105
1106static int
1107hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1108{
1109	struct hfsc_sched *q = qdisc_priv(sch);
1110	struct hfsc_class *cl = (struct hfsc_class *)arg;
1111
1112	if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1113		return -EBUSY;
1114
1115	sch_tree_lock(sch);
1116
1117	list_del(&cl->siblings);
1118	hfsc_adjust_levels(cl->cl_parent);
1119
1120	qdisc_purge_queue(cl->qdisc);
1121	qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1122
1123	sch_tree_unlock(sch);
1124
1125	hfsc_destroy_class(sch, cl);
1126	return 0;
1127}
1128
1129static struct hfsc_class *
1130hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1131{
1132	struct hfsc_sched *q = qdisc_priv(sch);
1133	struct hfsc_class *head, *cl;
1134	struct tcf_result res;
1135	struct tcf_proto *tcf;
1136	int result;
1137
1138	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1139	    (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1140		if (cl->level == 0)
1141			return cl;
1142
1143	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1144	head = &q->root;
1145	tcf = rcu_dereference_bh(q->root.filter_list);
1146	while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
1147#ifdef CONFIG_NET_CLS_ACT
1148		switch (result) {
1149		case TC_ACT_QUEUED:
1150		case TC_ACT_STOLEN:
1151		case TC_ACT_TRAP:
1152			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1153			fallthrough;
1154		case TC_ACT_SHOT:
1155			return NULL;
1156		}
1157#endif
1158		cl = (struct hfsc_class *)res.class;
1159		if (!cl) {
1160			cl = hfsc_find_class(res.classid, sch);
1161			if (!cl)
1162				break; /* filter selected invalid classid */
1163			if (cl->level >= head->level)
1164				break; /* filter may only point downwards */
1165		}
1166
1167		if (cl->level == 0)
1168			return cl; /* hit leaf class */
1169
1170		/* apply inner filter chain */
1171		tcf = rcu_dereference_bh(cl->filter_list);
1172		head = cl;
1173	}
1174
1175	/* classification failed, try default class */
1176	cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1177	if (cl == NULL || cl->level > 0)
1178		return NULL;
1179
1180	return cl;
1181}
1182
1183static int
1184hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1185		 struct Qdisc **old, struct netlink_ext_ack *extack)
1186{
1187	struct hfsc_class *cl = (struct hfsc_class *)arg;
1188
1189	if (cl->level > 0)
1190		return -EINVAL;
1191	if (new == NULL) {
1192		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1193					cl->cl_common.classid, NULL);
1194		if (new == NULL)
1195			new = &noop_qdisc;
1196	}
1197
1198	*old = qdisc_replace(sch, new, &cl->qdisc);
1199	return 0;
1200}
1201
1202static struct Qdisc *
1203hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1204{
1205	struct hfsc_class *cl = (struct hfsc_class *)arg;
1206
1207	if (cl->level == 0)
1208		return cl->qdisc;
1209
1210	return NULL;
1211}
1212
1213static void
1214hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1215{
1216	struct hfsc_class *cl = (struct hfsc_class *)arg;
1217
1218	/* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
1219	 * needs to be called explicitly to remove a class from vttree.
1220	 */
1221	update_vf(cl, 0, 0);
1222	if (cl->cl_flags & HFSC_RSC)
1223		eltree_remove(cl);
1224}
1225
1226static unsigned long
1227hfsc_search_class(struct Qdisc *sch, u32 classid)
1228{
1229	return (unsigned long)hfsc_find_class(classid, sch);
1230}
1231
1232static unsigned long
1233hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1234{
1235	struct hfsc_class *p = (struct hfsc_class *)parent;
1236	struct hfsc_class *cl = hfsc_find_class(classid, sch);
1237
1238	if (cl != NULL) {
1239		if (p != NULL && p->level <= cl->level)
1240			return 0;
1241		cl->filter_cnt++;
1242	}
1243
1244	return (unsigned long)cl;
1245}
1246
1247static void
1248hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1249{
1250	struct hfsc_class *cl = (struct hfsc_class *)arg;
1251
1252	cl->filter_cnt--;
1253}
1254
1255static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
1256					struct netlink_ext_ack *extack)
1257{
1258	struct hfsc_sched *q = qdisc_priv(sch);
1259	struct hfsc_class *cl = (struct hfsc_class *)arg;
1260
1261	if (cl == NULL)
1262		cl = &q->root;
1263
1264	return cl->block;
1265}
1266
1267static int
1268hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1269{
1270	struct tc_service_curve tsc;
1271
1272	tsc.m1 = sm2m(sc->sm1);
1273	tsc.d  = dx2d(sc->dx);
1274	tsc.m2 = sm2m(sc->sm2);
1275	if (nla_put(skb, attr, sizeof(tsc), &tsc))
1276		goto nla_put_failure;
1277
1278	return skb->len;
1279
1280 nla_put_failure:
1281	return -1;
1282}
1283
1284static int
1285hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1286{
1287	if ((cl->cl_flags & HFSC_RSC) &&
1288	    (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1289		goto nla_put_failure;
1290
1291	if ((cl->cl_flags & HFSC_FSC) &&
1292	    (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1293		goto nla_put_failure;
1294
1295	if ((cl->cl_flags & HFSC_USC) &&
1296	    (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1297		goto nla_put_failure;
1298
1299	return skb->len;
1300
1301 nla_put_failure:
1302	return -1;
1303}
1304
1305static int
1306hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1307		struct tcmsg *tcm)
1308{
1309	struct hfsc_class *cl = (struct hfsc_class *)arg;
1310	struct nlattr *nest;
1311
1312	tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1313					  TC_H_ROOT;
1314	tcm->tcm_handle = cl->cl_common.classid;
1315	if (cl->level == 0)
1316		tcm->tcm_info = cl->qdisc->handle;
1317
1318	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1319	if (nest == NULL)
1320		goto nla_put_failure;
1321	if (hfsc_dump_curves(skb, cl) < 0)
1322		goto nla_put_failure;
1323	return nla_nest_end(skb, nest);
1324
1325 nla_put_failure:
1326	nla_nest_cancel(skb, nest);
1327	return -EMSGSIZE;
1328}
1329
1330static int
1331hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1332	struct gnet_dump *d)
1333{
1334	struct hfsc_class *cl = (struct hfsc_class *)arg;
1335	struct tc_hfsc_stats xstats;
1336	__u32 qlen;
1337
1338	qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
1339	xstats.level   = cl->level;
1340	xstats.period  = cl->cl_vtperiod;
1341	xstats.work    = cl->cl_total;
1342	xstats.rtwork  = cl->cl_cumul;
1343
1344	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d, NULL, &cl->bstats) < 0 ||
1345	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1346	    gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1347		return -1;
1348
1349	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1350}
1351
1352
1353
1354static void
1355hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1356{
1357	struct hfsc_sched *q = qdisc_priv(sch);
1358	struct hfsc_class *cl;
1359	unsigned int i;
1360
1361	if (arg->stop)
1362		return;
1363
1364	for (i = 0; i < q->clhash.hashsize; i++) {
1365		hlist_for_each_entry(cl, &q->clhash.hash[i],
1366				     cl_common.hnode) {
1367			if (arg->count < arg->skip) {
1368				arg->count++;
1369				continue;
1370			}
1371			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1372				arg->stop = 1;
1373				return;
1374			}
1375			arg->count++;
1376		}
1377	}
1378}
1379
1380static void
1381hfsc_schedule_watchdog(struct Qdisc *sch)
1382{
1383	struct hfsc_sched *q = qdisc_priv(sch);
1384	struct hfsc_class *cl;
1385	u64 next_time = 0;
1386
1387	cl = eltree_get_minel(q);
1388	if (cl)
1389		next_time = cl->cl_e;
1390	if (q->root.cl_cfmin != 0) {
1391		if (next_time == 0 || next_time > q->root.cl_cfmin)
1392			next_time = q->root.cl_cfmin;
1393	}
1394	if (next_time)
1395		qdisc_watchdog_schedule(&q->watchdog, next_time);
1396}
1397
1398static int
1399hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
1400		struct netlink_ext_ack *extack)
1401{
1402	struct hfsc_sched *q = qdisc_priv(sch);
1403	struct tc_hfsc_qopt *qopt;
1404	int err;
1405
1406	qdisc_watchdog_init(&q->watchdog, sch);
1407
1408	if (!opt || nla_len(opt) < sizeof(*qopt))
1409		return -EINVAL;
1410	qopt = nla_data(opt);
1411
1412	q->defcls = qopt->defcls;
1413	err = qdisc_class_hash_init(&q->clhash);
1414	if (err < 0)
1415		return err;
1416	q->eligible = RB_ROOT;
1417
1418	err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
1419	if (err)
1420		return err;
1421
1422	q->root.cl_common.classid = sch->handle;
1423	q->root.sched   = q;
1424	q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1425					  sch->handle, NULL);
1426	if (q->root.qdisc == NULL)
1427		q->root.qdisc = &noop_qdisc;
1428	else
1429		qdisc_hash_add(q->root.qdisc, true);
1430	INIT_LIST_HEAD(&q->root.children);
1431	q->root.vt_tree = RB_ROOT;
1432	q->root.cf_tree = RB_ROOT;
1433
1434	qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1435	qdisc_class_hash_grow(sch, &q->clhash);
1436
1437	return 0;
1438}
1439
1440static int
1441hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
1442		  struct netlink_ext_ack *extack)
1443{
1444	struct hfsc_sched *q = qdisc_priv(sch);
1445	struct tc_hfsc_qopt *qopt;
1446
1447	if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1448		return -EINVAL;
1449	qopt = nla_data(opt);
1450
1451	sch_tree_lock(sch);
1452	q->defcls = qopt->defcls;
1453	sch_tree_unlock(sch);
1454
1455	return 0;
1456}
1457
1458static void
1459hfsc_reset_class(struct hfsc_class *cl)
1460{
1461	cl->cl_total        = 0;
1462	cl->cl_cumul        = 0;
1463	cl->cl_d            = 0;
1464	cl->cl_e            = 0;
1465	cl->cl_vt           = 0;
1466	cl->cl_vtadj        = 0;
1467	cl->cl_cvtmin       = 0;
1468	cl->cl_cvtoff       = 0;
1469	cl->cl_vtperiod     = 0;
1470	cl->cl_parentperiod = 0;
1471	cl->cl_f            = 0;
1472	cl->cl_myf          = 0;
1473	cl->cl_cfmin        = 0;
1474	cl->cl_nactive      = 0;
1475
1476	cl->vt_tree = RB_ROOT;
1477	cl->cf_tree = RB_ROOT;
1478	qdisc_reset(cl->qdisc);
1479
1480	if (cl->cl_flags & HFSC_RSC)
1481		rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1482	if (cl->cl_flags & HFSC_FSC)
1483		rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1484	if (cl->cl_flags & HFSC_USC)
1485		rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1486}
1487
1488static void
1489hfsc_reset_qdisc(struct Qdisc *sch)
1490{
1491	struct hfsc_sched *q = qdisc_priv(sch);
1492	struct hfsc_class *cl;
1493	unsigned int i;
1494
1495	for (i = 0; i < q->clhash.hashsize; i++) {
1496		hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1497			hfsc_reset_class(cl);
1498	}
1499	q->eligible = RB_ROOT;
1500	qdisc_watchdog_cancel(&q->watchdog);
1501}
1502
1503static void
1504hfsc_destroy_qdisc(struct Qdisc *sch)
1505{
1506	struct hfsc_sched *q = qdisc_priv(sch);
1507	struct hlist_node *next;
1508	struct hfsc_class *cl;
1509	unsigned int i;
1510
1511	for (i = 0; i < q->clhash.hashsize; i++) {
1512		hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
1513			tcf_block_put(cl->block);
1514			cl->block = NULL;
1515		}
1516	}
1517	for (i = 0; i < q->clhash.hashsize; i++) {
1518		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1519					  cl_common.hnode)
1520			hfsc_destroy_class(sch, cl);
1521	}
1522	qdisc_class_hash_destroy(&q->clhash);
1523	qdisc_watchdog_cancel(&q->watchdog);
1524}
1525
1526static int
1527hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1528{
1529	struct hfsc_sched *q = qdisc_priv(sch);
1530	unsigned char *b = skb_tail_pointer(skb);
1531	struct tc_hfsc_qopt qopt;
1532
1533	qopt.defcls = q->defcls;
1534	if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1535		goto nla_put_failure;
1536	return skb->len;
1537
1538 nla_put_failure:
1539	nlmsg_trim(skb, b);
1540	return -1;
1541}
1542
1543static int
1544hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
1545{
1546	unsigned int len = qdisc_pkt_len(skb);
1547	struct hfsc_class *cl;
1548	int err;
1549	bool first;
1550
1551	cl = hfsc_classify(skb, sch, &err);
1552	if (cl == NULL) {
1553		if (err & __NET_XMIT_BYPASS)
1554			qdisc_qstats_drop(sch);
1555		__qdisc_drop(skb, to_free);
1556		return err;
1557	}
1558
1559	first = !cl->qdisc->q.qlen;
1560	err = qdisc_enqueue(skb, cl->qdisc, to_free);
1561	if (unlikely(err != NET_XMIT_SUCCESS)) {
1562		if (net_xmit_drop_count(err)) {
1563			cl->qstats.drops++;
1564			qdisc_qstats_drop(sch);
1565		}
1566		return err;
1567	}
1568
1569	if (first) {
1570		if (cl->cl_flags & HFSC_RSC)
1571			init_ed(cl, len);
1572		if (cl->cl_flags & HFSC_FSC)
1573			init_vf(cl, len);
1574		/*
1575		 * If this is the first packet, isolate the head so an eventual
1576		 * head drop before the first dequeue operation has no chance
1577		 * to invalidate the deadline.
1578		 */
1579		if (cl->cl_flags & HFSC_RSC)
1580			cl->qdisc->ops->peek(cl->qdisc);
1581
1582	}
1583
1584	sch->qstats.backlog += len;
1585	sch->q.qlen++;
1586
1587	return NET_XMIT_SUCCESS;
1588}
1589
1590static struct sk_buff *
1591hfsc_dequeue(struct Qdisc *sch)
1592{
1593	struct hfsc_sched *q = qdisc_priv(sch);
1594	struct hfsc_class *cl;
1595	struct sk_buff *skb;
1596	u64 cur_time;
1597	unsigned int next_len;
1598	int realtime = 0;
1599
1600	if (sch->q.qlen == 0)
1601		return NULL;
1602
1603	cur_time = psched_get_time();
1604
1605	/*
1606	 * if there are eligible classes, use real-time criteria.
1607	 * find the class with the minimum deadline among
1608	 * the eligible classes.
1609	 */
1610	cl = eltree_get_mindl(q, cur_time);
1611	if (cl) {
1612		realtime = 1;
1613	} else {
1614		/*
1615		 * use link-sharing criteria
1616		 * get the class with the minimum vt in the hierarchy
1617		 */
1618		cl = vttree_get_minvt(&q->root, cur_time);
1619		if (cl == NULL) {
1620			qdisc_qstats_overlimit(sch);
1621			hfsc_schedule_watchdog(sch);
1622			return NULL;
1623		}
1624	}
1625
1626	skb = qdisc_dequeue_peeked(cl->qdisc);
1627	if (skb == NULL) {
1628		qdisc_warn_nonwc("HFSC", cl->qdisc);
1629		return NULL;
1630	}
1631
1632	bstats_update(&cl->bstats, skb);
1633	update_vf(cl, qdisc_pkt_len(skb), cur_time);
1634	if (realtime)
1635		cl->cl_cumul += qdisc_pkt_len(skb);
1636
1637	if (cl->cl_flags & HFSC_RSC) {
1638		if (cl->qdisc->q.qlen != 0) {
1639			/* update ed */
1640			next_len = qdisc_peek_len(cl->qdisc);
1641			if (realtime)
1642				update_ed(cl, next_len);
1643			else
1644				update_d(cl, next_len);
1645		} else {
1646			/* the class becomes passive */
1647			eltree_remove(cl);
1648		}
1649	}
1650
1651	qdisc_bstats_update(sch, skb);
1652	qdisc_qstats_backlog_dec(sch, skb);
1653	sch->q.qlen--;
1654
1655	return skb;
1656}
1657
1658static const struct Qdisc_class_ops hfsc_class_ops = {
1659	.change		= hfsc_change_class,
1660	.delete		= hfsc_delete_class,
1661	.graft		= hfsc_graft_class,
1662	.leaf		= hfsc_class_leaf,
1663	.qlen_notify	= hfsc_qlen_notify,
1664	.find		= hfsc_search_class,
1665	.bind_tcf	= hfsc_bind_tcf,
1666	.unbind_tcf	= hfsc_unbind_tcf,
1667	.tcf_block	= hfsc_tcf_block,
1668	.dump		= hfsc_dump_class,
1669	.dump_stats	= hfsc_dump_class_stats,
1670	.walk		= hfsc_walk
1671};
1672
1673static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1674	.id		= "hfsc",
1675	.init		= hfsc_init_qdisc,
1676	.change		= hfsc_change_qdisc,
1677	.reset		= hfsc_reset_qdisc,
1678	.destroy	= hfsc_destroy_qdisc,
1679	.dump		= hfsc_dump_qdisc,
1680	.enqueue	= hfsc_enqueue,
1681	.dequeue	= hfsc_dequeue,
1682	.peek		= qdisc_peek_dequeued,
1683	.cl_ops		= &hfsc_class_ops,
1684	.priv_size	= sizeof(struct hfsc_sched),
1685	.owner		= THIS_MODULE
1686};
1687
1688static int __init
1689hfsc_init(void)
1690{
1691	return register_qdisc(&hfsc_qdisc_ops);
1692}
1693
1694static void __exit
1695hfsc_cleanup(void)
1696{
1697	unregister_qdisc(&hfsc_qdisc_ops);
1698}
1699
1700MODULE_LICENSE("GPL");
1701module_init(hfsc_init);
1702module_exit(hfsc_cleanup);
1703