xref: /openbmc/linux/net/sched/sch_hfsc.c (revision 87c2ce3b)
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/config.h>
54 #include <linux/module.h>
55 #include <linux/types.h>
56 #include <linux/errno.h>
57 #include <linux/jiffies.h>
58 #include <linux/compiler.h>
59 #include <linux/spinlock.h>
60 #include <linux/skbuff.h>
61 #include <linux/string.h>
62 #include <linux/slab.h>
63 #include <linux/timer.h>
64 #include <linux/list.h>
65 #include <linux/rbtree.h>
66 #include <linux/init.h>
67 #include <linux/netdevice.h>
68 #include <linux/rtnetlink.h>
69 #include <linux/pkt_sched.h>
70 #include <net/pkt_sched.h>
71 #include <net/pkt_cls.h>
72 #include <asm/system.h>
73 #include <asm/div64.h>
74 
75 #define HFSC_DEBUG 1
76 
77 /*
78  * kernel internal service curve representation:
79  *   coordinates are given by 64 bit unsigned integers.
80  *   x-axis: unit is clock count.
81  *   y-axis: unit is byte.
82  *
83  *   The service curve parameters are converted to the internal
84  *   representation. The slope values are scaled to avoid overflow.
85  *   the inverse slope values as well as the y-projection of the 1st
86  *   segment are kept in order to to avoid 64-bit divide operations
87  *   that are expensive on 32-bit architectures.
88  */
89 
90 struct internal_sc
91 {
92 	u64	sm1;	/* scaled slope of the 1st segment */
93 	u64	ism1;	/* scaled inverse-slope of the 1st segment */
94 	u64	dx;	/* the x-projection of the 1st segment */
95 	u64	dy;	/* the y-projection of the 1st segment */
96 	u64	sm2;	/* scaled slope of the 2nd segment */
97 	u64	ism2;	/* scaled inverse-slope of the 2nd segment */
98 };
99 
100 /* runtime service curve */
101 struct runtime_sc
102 {
103 	u64	x;	/* current starting position on x-axis */
104 	u64	y;	/* current starting position on y-axis */
105 	u64	sm1;	/* scaled slope of the 1st segment */
106 	u64	ism1;	/* scaled inverse-slope of the 1st segment */
107 	u64	dx;	/* the x-projection of the 1st segment */
108 	u64	dy;	/* the y-projection of the 1st segment */
109 	u64	sm2;	/* scaled slope of the 2nd segment */
110 	u64	ism2;	/* scaled inverse-slope of the 2nd segment */
111 };
112 
113 enum hfsc_class_flags
114 {
115 	HFSC_RSC = 0x1,
116 	HFSC_FSC = 0x2,
117 	HFSC_USC = 0x4
118 };
119 
120 struct hfsc_class
121 {
122 	u32		classid;	/* class id */
123 	unsigned int	refcnt;		/* usage count */
124 
125 	struct gnet_stats_basic bstats;
126 	struct gnet_stats_queue qstats;
127 	struct gnet_stats_rate_est rate_est;
128 	spinlock_t	*stats_lock;
129 	unsigned int	level;		/* class level in hierarchy */
130 	struct tcf_proto *filter_list;	/* filter list */
131 	unsigned int	filter_cnt;	/* filter count */
132 
133 	struct hfsc_sched *sched;	/* scheduler data */
134 	struct hfsc_class *cl_parent;	/* parent class */
135 	struct list_head siblings;	/* sibling classes */
136 	struct list_head children;	/* child classes */
137 	struct Qdisc	*qdisc;		/* leaf qdisc */
138 
139 	struct rb_node el_node;		/* qdisc's eligible tree member */
140 	struct rb_root vt_tree;		/* active children sorted by cl_vt */
141 	struct rb_node vt_node;		/* parent's vt_tree member */
142 	struct rb_root cf_tree;		/* active children sorted by cl_f */
143 	struct rb_node cf_node;		/* parent's cf_heap member */
144 	struct list_head hlist;		/* hash list member */
145 	struct list_head dlist;		/* drop list member */
146 
147 	u64	cl_total;		/* total work in bytes */
148 	u64	cl_cumul;		/* cumulative work in bytes done by
149 					   real-time criteria */
150 
151 	u64 	cl_d;			/* deadline*/
152 	u64 	cl_e;			/* eligible time */
153 	u64	cl_vt;			/* virtual time */
154 	u64	cl_f;			/* time when this class will fit for
155 					   link-sharing, max(myf, cfmin) */
156 	u64	cl_myf;			/* my fit-time (calculated from this
157 					   class's own upperlimit curve) */
158 	u64	cl_myfadj;		/* my fit-time adjustment (to cancel
159 					   history dependence) */
160 	u64	cl_cfmin;		/* earliest children's fit-time (used
161 					   with cl_myf to obtain cl_f) */
162 	u64	cl_cvtmin;		/* minimal virtual time among the
163 					   children fit for link-sharing
164 					   (monotonic within a period) */
165 	u64	cl_vtadj;		/* intra-period cumulative vt
166 					   adjustment */
167 	u64	cl_vtoff;		/* inter-period cumulative vt offset */
168 	u64	cl_cvtmax;		/* max child's vt in the last period */
169 	u64	cl_cvtoff;		/* cumulative cvtmax of all periods */
170 	u64	cl_pcvtoff;		/* parent's cvtoff at initalization
171 					   time */
172 
173 	struct internal_sc cl_rsc;	/* internal real-time service curve */
174 	struct internal_sc cl_fsc;	/* internal fair service curve */
175 	struct internal_sc cl_usc;	/* internal upperlimit service curve */
176 	struct runtime_sc cl_deadline;	/* deadline curve */
177 	struct runtime_sc cl_eligible;	/* eligible curve */
178 	struct runtime_sc cl_virtual;	/* virtual curve */
179 	struct runtime_sc cl_ulimit;	/* upperlimit curve */
180 
181 	unsigned long	cl_flags;	/* which curves are valid */
182 	unsigned long	cl_vtperiod;	/* vt period sequence number */
183 	unsigned long	cl_parentperiod;/* parent's vt period sequence number*/
184 	unsigned long	cl_nactive;	/* number of active children */
185 };
186 
187 #define HFSC_HSIZE	16
188 
189 struct hfsc_sched
190 {
191 	u16	defcls;				/* default class id */
192 	struct hfsc_class root;			/* root class */
193 	struct list_head clhash[HFSC_HSIZE];	/* class hash */
194 	struct rb_root eligible;		/* eligible tree */
195 	struct list_head droplist;		/* active leaf class list (for
196 						   dropping) */
197 	struct sk_buff_head requeue;		/* requeued packet */
198 	struct timer_list wd_timer;		/* watchdog timer */
199 };
200 
201 /*
202  * macros
203  */
204 #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
205 #include <linux/time.h>
206 #undef PSCHED_GET_TIME
207 #define PSCHED_GET_TIME(stamp)						\
208 do {									\
209 	struct timeval tv;						\
210 	do_gettimeofday(&tv);						\
211 	(stamp) = 1ULL * USEC_PER_SEC * tv.tv_sec + tv.tv_usec;		\
212 } while (0)
213 #endif
214 
215 #if HFSC_DEBUG
216 #define ASSERT(cond)							\
217 do {									\
218 	if (unlikely(!(cond)))						\
219 		printk("assertion %s failed at %s:%i (%s)\n",		\
220 		       #cond, __FILE__, __LINE__, __FUNCTION__);	\
221 } while (0)
222 #else
223 #define ASSERT(cond)
224 #endif /* HFSC_DEBUG */
225 
226 #define	HT_INFINITY	0xffffffffffffffffULL	/* infinite time value */
227 
228 
229 /*
230  * eligible tree holds backlogged classes being sorted by their eligible times.
231  * there is one eligible tree per hfsc instance.
232  */
233 
234 static void
235 eltree_insert(struct hfsc_class *cl)
236 {
237 	struct rb_node **p = &cl->sched->eligible.rb_node;
238 	struct rb_node *parent = NULL;
239 	struct hfsc_class *cl1;
240 
241 	while (*p != NULL) {
242 		parent = *p;
243 		cl1 = rb_entry(parent, struct hfsc_class, el_node);
244 		if (cl->cl_e >= cl1->cl_e)
245 			p = &parent->rb_right;
246 		else
247 			p = &parent->rb_left;
248 	}
249 	rb_link_node(&cl->el_node, parent, p);
250 	rb_insert_color(&cl->el_node, &cl->sched->eligible);
251 }
252 
253 static inline void
254 eltree_remove(struct hfsc_class *cl)
255 {
256 	rb_erase(&cl->el_node, &cl->sched->eligible);
257 }
258 
259 static inline void
260 eltree_update(struct hfsc_class *cl)
261 {
262 	eltree_remove(cl);
263 	eltree_insert(cl);
264 }
265 
266 /* find the class with the minimum deadline among the eligible classes */
267 static inline struct hfsc_class *
268 eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
269 {
270 	struct hfsc_class *p, *cl = NULL;
271 	struct rb_node *n;
272 
273 	for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
274 		p = rb_entry(n, struct hfsc_class, el_node);
275 		if (p->cl_e > cur_time)
276 			break;
277 		if (cl == NULL || p->cl_d < cl->cl_d)
278 			cl = p;
279 	}
280 	return cl;
281 }
282 
283 /* find the class with minimum eligible time among the eligible classes */
284 static inline struct hfsc_class *
285 eltree_get_minel(struct hfsc_sched *q)
286 {
287 	struct rb_node *n;
288 
289 	n = rb_first(&q->eligible);
290 	if (n == NULL)
291 		return NULL;
292 	return rb_entry(n, struct hfsc_class, el_node);
293 }
294 
295 /*
296  * vttree holds holds backlogged child classes being sorted by their virtual
297  * time. each intermediate class has one vttree.
298  */
299 static void
300 vttree_insert(struct hfsc_class *cl)
301 {
302 	struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
303 	struct rb_node *parent = NULL;
304 	struct hfsc_class *cl1;
305 
306 	while (*p != NULL) {
307 		parent = *p;
308 		cl1 = rb_entry(parent, struct hfsc_class, vt_node);
309 		if (cl->cl_vt >= cl1->cl_vt)
310 			p = &parent->rb_right;
311 		else
312 			p = &parent->rb_left;
313 	}
314 	rb_link_node(&cl->vt_node, parent, p);
315 	rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
316 }
317 
318 static inline void
319 vttree_remove(struct hfsc_class *cl)
320 {
321 	rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
322 }
323 
324 static inline void
325 vttree_update(struct hfsc_class *cl)
326 {
327 	vttree_remove(cl);
328 	vttree_insert(cl);
329 }
330 
331 static inline struct hfsc_class *
332 vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
333 {
334 	struct hfsc_class *p;
335 	struct rb_node *n;
336 
337 	for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
338 		p = rb_entry(n, struct hfsc_class, vt_node);
339 		if (p->cl_f <= cur_time)
340 			return p;
341 	}
342 	return NULL;
343 }
344 
345 /*
346  * get the leaf class with the minimum vt in the hierarchy
347  */
348 static struct hfsc_class *
349 vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
350 {
351 	/* if root-class's cfmin is bigger than cur_time nothing to do */
352 	if (cl->cl_cfmin > cur_time)
353 		return NULL;
354 
355 	while (cl->level > 0) {
356 		cl = vttree_firstfit(cl, cur_time);
357 		if (cl == NULL)
358 			return NULL;
359 		/*
360 		 * update parent's cl_cvtmin.
361 		 */
362 		if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
363 			cl->cl_parent->cl_cvtmin = cl->cl_vt;
364 	}
365 	return cl;
366 }
367 
368 static void
369 cftree_insert(struct hfsc_class *cl)
370 {
371 	struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
372 	struct rb_node *parent = NULL;
373 	struct hfsc_class *cl1;
374 
375 	while (*p != NULL) {
376 		parent = *p;
377 		cl1 = rb_entry(parent, struct hfsc_class, cf_node);
378 		if (cl->cl_f >= cl1->cl_f)
379 			p = &parent->rb_right;
380 		else
381 			p = &parent->rb_left;
382 	}
383 	rb_link_node(&cl->cf_node, parent, p);
384 	rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
385 }
386 
387 static inline void
388 cftree_remove(struct hfsc_class *cl)
389 {
390 	rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
391 }
392 
393 static inline void
394 cftree_update(struct hfsc_class *cl)
395 {
396 	cftree_remove(cl);
397 	cftree_insert(cl);
398 }
399 
400 /*
401  * service curve support functions
402  *
403  *  external service curve parameters
404  *	m: bps
405  *	d: us
406  *  internal service curve parameters
407  *	sm: (bytes/psched_us) << SM_SHIFT
408  *	ism: (psched_us/byte) << ISM_SHIFT
409  *	dx: psched_us
410  *
411  * Clock source resolution (CONFIG_NET_SCH_CLK_*)
412  *  JIFFIES: for 48<=HZ<=1534 resolution is between 0.63us and 1.27us.
413  *  CPU: resolution is between 0.5us and 1us.
414  *  GETTIMEOFDAY: resolution is exactly 1us.
415  *
416  * sm and ism are scaled in order to keep effective digits.
417  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
418  * digits in decimal using the following table.
419  *
420  * Note: We can afford the additional accuracy (altq hfsc keeps at most
421  * 3 effective digits) thanks to the fact that linux clock is bounded
422  * much more tightly.
423  *
424  *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
425  *  ------------+-------------------------------------------------------
426  *  bytes/0.5us   6.25e-3    62.5e-3    625e-3     6250e-e    62500e-3
427  *  bytes/us      12.5e-3    125e-3     1250e-3    12500e-3   125000e-3
428  *  bytes/1.27us  15.875e-3  158.75e-3  1587.5e-3  15875e-3   158750e-3
429  *
430  *  0.5us/byte    160        16         1.6        0.16       0.016
431  *  us/byte       80         8          0.8        0.08       0.008
432  *  1.27us/byte   63         6.3        0.63       0.063      0.0063
433  */
434 #define	SM_SHIFT	20
435 #define	ISM_SHIFT	18
436 
437 #define	SM_MASK		((1ULL << SM_SHIFT) - 1)
438 #define	ISM_MASK	((1ULL << ISM_SHIFT) - 1)
439 
440 static inline u64
441 seg_x2y(u64 x, u64 sm)
442 {
443 	u64 y;
444 
445 	/*
446 	 * compute
447 	 *	y = x * sm >> SM_SHIFT
448 	 * but divide it for the upper and lower bits to avoid overflow
449 	 */
450 	y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
451 	return y;
452 }
453 
454 static inline u64
455 seg_y2x(u64 y, u64 ism)
456 {
457 	u64 x;
458 
459 	if (y == 0)
460 		x = 0;
461 	else if (ism == HT_INFINITY)
462 		x = HT_INFINITY;
463 	else {
464 		x = (y >> ISM_SHIFT) * ism
465 		    + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
466 	}
467 	return x;
468 }
469 
470 /* Convert m (bps) into sm (bytes/psched us) */
471 static u64
472 m2sm(u32 m)
473 {
474 	u64 sm;
475 
476 	sm = ((u64)m << SM_SHIFT);
477 	sm += PSCHED_JIFFIE2US(HZ) - 1;
478 	do_div(sm, PSCHED_JIFFIE2US(HZ));
479 	return sm;
480 }
481 
482 /* convert m (bps) into ism (psched us/byte) */
483 static u64
484 m2ism(u32 m)
485 {
486 	u64 ism;
487 
488 	if (m == 0)
489 		ism = HT_INFINITY;
490 	else {
491 		ism = ((u64)PSCHED_JIFFIE2US(HZ) << ISM_SHIFT);
492 		ism += m - 1;
493 		do_div(ism, m);
494 	}
495 	return ism;
496 }
497 
498 /* convert d (us) into dx (psched us) */
499 static u64
500 d2dx(u32 d)
501 {
502 	u64 dx;
503 
504 	dx = ((u64)d * PSCHED_JIFFIE2US(HZ));
505 	dx += USEC_PER_SEC - 1;
506 	do_div(dx, USEC_PER_SEC);
507 	return dx;
508 }
509 
510 /* convert sm (bytes/psched us) into m (bps) */
511 static u32
512 sm2m(u64 sm)
513 {
514 	u64 m;
515 
516 	m = (sm * PSCHED_JIFFIE2US(HZ)) >> SM_SHIFT;
517 	return (u32)m;
518 }
519 
520 /* convert dx (psched us) into d (us) */
521 static u32
522 dx2d(u64 dx)
523 {
524 	u64 d;
525 
526 	d = dx * USEC_PER_SEC;
527 	do_div(d, PSCHED_JIFFIE2US(HZ));
528 	return (u32)d;
529 }
530 
531 static void
532 sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
533 {
534 	isc->sm1  = m2sm(sc->m1);
535 	isc->ism1 = m2ism(sc->m1);
536 	isc->dx   = d2dx(sc->d);
537 	isc->dy   = seg_x2y(isc->dx, isc->sm1);
538 	isc->sm2  = m2sm(sc->m2);
539 	isc->ism2 = m2ism(sc->m2);
540 }
541 
542 /*
543  * initialize the runtime service curve with the given internal
544  * service curve starting at (x, y).
545  */
546 static void
547 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
548 {
549 	rtsc->x	   = x;
550 	rtsc->y    = y;
551 	rtsc->sm1  = isc->sm1;
552 	rtsc->ism1 = isc->ism1;
553 	rtsc->dx   = isc->dx;
554 	rtsc->dy   = isc->dy;
555 	rtsc->sm2  = isc->sm2;
556 	rtsc->ism2 = isc->ism2;
557 }
558 
559 /*
560  * calculate the y-projection of the runtime service curve by the
561  * given x-projection value
562  */
563 static u64
564 rtsc_y2x(struct runtime_sc *rtsc, u64 y)
565 {
566 	u64 x;
567 
568 	if (y < rtsc->y)
569 		x = rtsc->x;
570 	else if (y <= rtsc->y + rtsc->dy) {
571 		/* x belongs to the 1st segment */
572 		if (rtsc->dy == 0)
573 			x = rtsc->x + rtsc->dx;
574 		else
575 			x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
576 	} else {
577 		/* x belongs to the 2nd segment */
578 		x = rtsc->x + rtsc->dx
579 		    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
580 	}
581 	return x;
582 }
583 
584 static u64
585 rtsc_x2y(struct runtime_sc *rtsc, u64 x)
586 {
587 	u64 y;
588 
589 	if (x <= rtsc->x)
590 		y = rtsc->y;
591 	else if (x <= rtsc->x + rtsc->dx)
592 		/* y belongs to the 1st segment */
593 		y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
594 	else
595 		/* y belongs to the 2nd segment */
596 		y = rtsc->y + rtsc->dy
597 		    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
598 	return y;
599 }
600 
601 /*
602  * update the runtime service curve by taking the minimum of the current
603  * runtime service curve and the service curve starting at (x, y).
604  */
605 static void
606 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
607 {
608 	u64 y1, y2, dx, dy;
609 	u32 dsm;
610 
611 	if (isc->sm1 <= isc->sm2) {
612 		/* service curve is convex */
613 		y1 = rtsc_x2y(rtsc, x);
614 		if (y1 < y)
615 			/* the current rtsc is smaller */
616 			return;
617 		rtsc->x = x;
618 		rtsc->y = y;
619 		return;
620 	}
621 
622 	/*
623 	 * service curve is concave
624 	 * compute the two y values of the current rtsc
625 	 *	y1: at x
626 	 *	y2: at (x + dx)
627 	 */
628 	y1 = rtsc_x2y(rtsc, x);
629 	if (y1 <= y) {
630 		/* rtsc is below isc, no change to rtsc */
631 		return;
632 	}
633 
634 	y2 = rtsc_x2y(rtsc, x + isc->dx);
635 	if (y2 >= y + isc->dy) {
636 		/* rtsc is above isc, replace rtsc by isc */
637 		rtsc->x = x;
638 		rtsc->y = y;
639 		rtsc->dx = isc->dx;
640 		rtsc->dy = isc->dy;
641 		return;
642 	}
643 
644 	/*
645 	 * the two curves intersect
646 	 * compute the offsets (dx, dy) using the reverse
647 	 * function of seg_x2y()
648 	 *	seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
649 	 */
650 	dx = (y1 - y) << SM_SHIFT;
651 	dsm = isc->sm1 - isc->sm2;
652 	do_div(dx, dsm);
653 	/*
654 	 * check if (x, y1) belongs to the 1st segment of rtsc.
655 	 * if so, add the offset.
656 	 */
657 	if (rtsc->x + rtsc->dx > x)
658 		dx += rtsc->x + rtsc->dx - x;
659 	dy = seg_x2y(dx, isc->sm1);
660 
661 	rtsc->x = x;
662 	rtsc->y = y;
663 	rtsc->dx = dx;
664 	rtsc->dy = dy;
665 	return;
666 }
667 
668 static void
669 init_ed(struct hfsc_class *cl, unsigned int next_len)
670 {
671 	u64 cur_time;
672 
673 	PSCHED_GET_TIME(cur_time);
674 
675 	/* update the deadline curve */
676 	rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
677 
678 	/*
679 	 * update the eligible curve.
680 	 * for concave, it is equal to the deadline curve.
681 	 * for convex, it is a linear curve with slope m2.
682 	 */
683 	cl->cl_eligible = cl->cl_deadline;
684 	if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
685 		cl->cl_eligible.dx = 0;
686 		cl->cl_eligible.dy = 0;
687 	}
688 
689 	/* compute e and d */
690 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
691 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
692 
693 	eltree_insert(cl);
694 }
695 
696 static void
697 update_ed(struct hfsc_class *cl, unsigned int next_len)
698 {
699 	cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
700 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
701 
702 	eltree_update(cl);
703 }
704 
705 static inline void
706 update_d(struct hfsc_class *cl, unsigned int next_len)
707 {
708 	cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
709 }
710 
711 static inline void
712 update_cfmin(struct hfsc_class *cl)
713 {
714 	struct rb_node *n = rb_first(&cl->cf_tree);
715 	struct hfsc_class *p;
716 
717 	if (n == NULL) {
718 		cl->cl_cfmin = 0;
719 		return;
720 	}
721 	p = rb_entry(n, struct hfsc_class, cf_node);
722 	cl->cl_cfmin = p->cl_f;
723 }
724 
725 static void
726 init_vf(struct hfsc_class *cl, unsigned int len)
727 {
728 	struct hfsc_class *max_cl;
729 	struct rb_node *n;
730 	u64 vt, f, cur_time;
731 	int go_active;
732 
733 	cur_time = 0;
734 	go_active = 1;
735 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
736 		if (go_active && cl->cl_nactive++ == 0)
737 			go_active = 1;
738 		else
739 			go_active = 0;
740 
741 		if (go_active) {
742 			n = rb_last(&cl->cl_parent->vt_tree);
743 			if (n != NULL) {
744 				max_cl = rb_entry(n, struct hfsc_class,vt_node);
745 				/*
746 				 * set vt to the average of the min and max
747 				 * classes.  if the parent's period didn't
748 				 * change, don't decrease vt of the class.
749 				 */
750 				vt = max_cl->cl_vt;
751 				if (cl->cl_parent->cl_cvtmin != 0)
752 					vt = (cl->cl_parent->cl_cvtmin + vt)/2;
753 
754 				if (cl->cl_parent->cl_vtperiod !=
755 				    cl->cl_parentperiod || vt > cl->cl_vt)
756 					cl->cl_vt = vt;
757 			} else {
758 				/*
759 				 * first child for a new parent backlog period.
760 				 * add parent's cvtmax to cvtoff to make a new
761 				 * vt (vtoff + vt) larger than the vt in the
762 				 * last period for all children.
763 				 */
764 				vt = cl->cl_parent->cl_cvtmax;
765 				cl->cl_parent->cl_cvtoff += vt;
766 				cl->cl_parent->cl_cvtmax = 0;
767 				cl->cl_parent->cl_cvtmin = 0;
768 				cl->cl_vt = 0;
769 			}
770 
771 			cl->cl_vtoff = cl->cl_parent->cl_cvtoff -
772 							cl->cl_pcvtoff;
773 
774 			/* update the virtual curve */
775 			vt = cl->cl_vt + cl->cl_vtoff;
776 			rtsc_min(&cl->cl_virtual, &cl->cl_fsc, vt,
777 			                              cl->cl_total);
778 			if (cl->cl_virtual.x == vt) {
779 				cl->cl_virtual.x -= cl->cl_vtoff;
780 				cl->cl_vtoff = 0;
781 			}
782 			cl->cl_vtadj = 0;
783 
784 			cl->cl_vtperiod++;  /* increment vt period */
785 			cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
786 			if (cl->cl_parent->cl_nactive == 0)
787 				cl->cl_parentperiod++;
788 			cl->cl_f = 0;
789 
790 			vttree_insert(cl);
791 			cftree_insert(cl);
792 
793 			if (cl->cl_flags & HFSC_USC) {
794 				/* class has upper limit curve */
795 				if (cur_time == 0)
796 					PSCHED_GET_TIME(cur_time);
797 
798 				/* update the ulimit curve */
799 				rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
800 				         cl->cl_total);
801 				/* compute myf */
802 				cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
803 				                      cl->cl_total);
804 				cl->cl_myfadj = 0;
805 			}
806 		}
807 
808 		f = max(cl->cl_myf, cl->cl_cfmin);
809 		if (f != cl->cl_f) {
810 			cl->cl_f = f;
811 			cftree_update(cl);
812 			update_cfmin(cl->cl_parent);
813 		}
814 	}
815 }
816 
817 static void
818 update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
819 {
820 	u64 f; /* , myf_bound, delta; */
821 	int go_passive = 0;
822 
823 	if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
824 		go_passive = 1;
825 
826 	for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
827 		cl->cl_total += len;
828 
829 		if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
830 			continue;
831 
832 		if (go_passive && --cl->cl_nactive == 0)
833 			go_passive = 1;
834 		else
835 			go_passive = 0;
836 
837 		if (go_passive) {
838 			/* no more active child, going passive */
839 
840 			/* update cvtmax of the parent class */
841 			if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
842 				cl->cl_parent->cl_cvtmax = cl->cl_vt;
843 
844 			/* remove this class from the vt tree */
845 			vttree_remove(cl);
846 
847 			cftree_remove(cl);
848 			update_cfmin(cl->cl_parent);
849 
850 			continue;
851 		}
852 
853 		/*
854 		 * update vt and f
855 		 */
856 		cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
857 		            - cl->cl_vtoff + cl->cl_vtadj;
858 
859 		/*
860 		 * if vt of the class is smaller than cvtmin,
861 		 * the class was skipped in the past due to non-fit.
862 		 * if so, we need to adjust vtadj.
863 		 */
864 		if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
865 			cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
866 			cl->cl_vt = cl->cl_parent->cl_cvtmin;
867 		}
868 
869 		/* update the vt tree */
870 		vttree_update(cl);
871 
872 		if (cl->cl_flags & HFSC_USC) {
873 			cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
874 			                                      cl->cl_total);
875 #if 0
876 			/*
877 			 * This code causes classes to stay way under their
878 			 * limit when multiple classes are used at gigabit
879 			 * speed. needs investigation. -kaber
880 			 */
881 			/*
882 			 * if myf lags behind by more than one clock tick
883 			 * from the current time, adjust myfadj to prevent
884 			 * a rate-limited class from going greedy.
885 			 * in a steady state under rate-limiting, myf
886 			 * fluctuates within one clock tick.
887 			 */
888 			myf_bound = cur_time - PSCHED_JIFFIE2US(1);
889 			if (cl->cl_myf < myf_bound) {
890 				delta = cur_time - cl->cl_myf;
891 				cl->cl_myfadj += delta;
892 				cl->cl_myf += delta;
893 			}
894 #endif
895 		}
896 
897 		f = max(cl->cl_myf, cl->cl_cfmin);
898 		if (f != cl->cl_f) {
899 			cl->cl_f = f;
900 			cftree_update(cl);
901 			update_cfmin(cl->cl_parent);
902 		}
903 	}
904 }
905 
906 static void
907 set_active(struct hfsc_class *cl, unsigned int len)
908 {
909 	if (cl->cl_flags & HFSC_RSC)
910 		init_ed(cl, len);
911 	if (cl->cl_flags & HFSC_FSC)
912 		init_vf(cl, len);
913 
914 	list_add_tail(&cl->dlist, &cl->sched->droplist);
915 }
916 
917 static void
918 set_passive(struct hfsc_class *cl)
919 {
920 	if (cl->cl_flags & HFSC_RSC)
921 		eltree_remove(cl);
922 
923 	list_del(&cl->dlist);
924 
925 	/*
926 	 * vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
927 	 * needs to be called explicitly to remove a class from vttree.
928 	 */
929 }
930 
931 /*
932  * hack to get length of first packet in queue.
933  */
934 static unsigned int
935 qdisc_peek_len(struct Qdisc *sch)
936 {
937 	struct sk_buff *skb;
938 	unsigned int len;
939 
940 	skb = sch->dequeue(sch);
941 	if (skb == NULL) {
942 		if (net_ratelimit())
943 			printk("qdisc_peek_len: non work-conserving qdisc ?\n");
944 		return 0;
945 	}
946 	len = skb->len;
947 	if (unlikely(sch->ops->requeue(skb, sch) != NET_XMIT_SUCCESS)) {
948 		if (net_ratelimit())
949 			printk("qdisc_peek_len: failed to requeue\n");
950 		return 0;
951 	}
952 	return len;
953 }
954 
955 static void
956 hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
957 {
958 	unsigned int len = cl->qdisc->q.qlen;
959 
960 	qdisc_reset(cl->qdisc);
961 	if (len > 0) {
962 		update_vf(cl, 0, 0);
963 		set_passive(cl);
964 		sch->q.qlen -= len;
965 	}
966 }
967 
968 static void
969 hfsc_adjust_levels(struct hfsc_class *cl)
970 {
971 	struct hfsc_class *p;
972 	unsigned int level;
973 
974 	do {
975 		level = 0;
976 		list_for_each_entry(p, &cl->children, siblings) {
977 			if (p->level > level)
978 				level = p->level;
979 		}
980 		cl->level = level + 1;
981 	} while ((cl = cl->cl_parent) != NULL);
982 }
983 
984 static inline unsigned int
985 hfsc_hash(u32 h)
986 {
987 	h ^= h >> 8;
988 	h ^= h >> 4;
989 
990 	return h & (HFSC_HSIZE - 1);
991 }
992 
993 static inline struct hfsc_class *
994 hfsc_find_class(u32 classid, struct Qdisc *sch)
995 {
996 	struct hfsc_sched *q = qdisc_priv(sch);
997 	struct hfsc_class *cl;
998 
999 	list_for_each_entry(cl, &q->clhash[hfsc_hash(classid)], hlist) {
1000 		if (cl->classid == classid)
1001 			return cl;
1002 	}
1003 	return NULL;
1004 }
1005 
1006 static void
1007 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
1008                 u64 cur_time)
1009 {
1010 	sc2isc(rsc, &cl->cl_rsc);
1011 	rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
1012 	cl->cl_eligible = cl->cl_deadline;
1013 	if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
1014 		cl->cl_eligible.dx = 0;
1015 		cl->cl_eligible.dy = 0;
1016 	}
1017 	cl->cl_flags |= HFSC_RSC;
1018 }
1019 
1020 static void
1021 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
1022 {
1023 	sc2isc(fsc, &cl->cl_fsc);
1024 	rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
1025 	cl->cl_flags |= HFSC_FSC;
1026 }
1027 
1028 static void
1029 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
1030                 u64 cur_time)
1031 {
1032 	sc2isc(usc, &cl->cl_usc);
1033 	rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
1034 	cl->cl_flags |= HFSC_USC;
1035 }
1036 
1037 static int
1038 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
1039                   struct rtattr **tca, unsigned long *arg)
1040 {
1041 	struct hfsc_sched *q = qdisc_priv(sch);
1042 	struct hfsc_class *cl = (struct hfsc_class *)*arg;
1043 	struct hfsc_class *parent = NULL;
1044 	struct rtattr *opt = tca[TCA_OPTIONS-1];
1045 	struct rtattr *tb[TCA_HFSC_MAX];
1046 	struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
1047 	u64 cur_time;
1048 
1049 	if (opt == NULL || rtattr_parse_nested(tb, TCA_HFSC_MAX, opt))
1050 		return -EINVAL;
1051 
1052 	if (tb[TCA_HFSC_RSC-1]) {
1053 		if (RTA_PAYLOAD(tb[TCA_HFSC_RSC-1]) < sizeof(*rsc))
1054 			return -EINVAL;
1055 		rsc = RTA_DATA(tb[TCA_HFSC_RSC-1]);
1056 		if (rsc->m1 == 0 && rsc->m2 == 0)
1057 			rsc = NULL;
1058 	}
1059 
1060 	if (tb[TCA_HFSC_FSC-1]) {
1061 		if (RTA_PAYLOAD(tb[TCA_HFSC_FSC-1]) < sizeof(*fsc))
1062 			return -EINVAL;
1063 		fsc = RTA_DATA(tb[TCA_HFSC_FSC-1]);
1064 		if (fsc->m1 == 0 && fsc->m2 == 0)
1065 			fsc = NULL;
1066 	}
1067 
1068 	if (tb[TCA_HFSC_USC-1]) {
1069 		if (RTA_PAYLOAD(tb[TCA_HFSC_USC-1]) < sizeof(*usc))
1070 			return -EINVAL;
1071 		usc = RTA_DATA(tb[TCA_HFSC_USC-1]);
1072 		if (usc->m1 == 0 && usc->m2 == 0)
1073 			usc = NULL;
1074 	}
1075 
1076 	if (cl != NULL) {
1077 		if (parentid) {
1078 			if (cl->cl_parent && cl->cl_parent->classid != parentid)
1079 				return -EINVAL;
1080 			if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
1081 				return -EINVAL;
1082 		}
1083 		PSCHED_GET_TIME(cur_time);
1084 
1085 		sch_tree_lock(sch);
1086 		if (rsc != NULL)
1087 			hfsc_change_rsc(cl, rsc, cur_time);
1088 		if (fsc != NULL)
1089 			hfsc_change_fsc(cl, fsc);
1090 		if (usc != NULL)
1091 			hfsc_change_usc(cl, usc, cur_time);
1092 
1093 		if (cl->qdisc->q.qlen != 0) {
1094 			if (cl->cl_flags & HFSC_RSC)
1095 				update_ed(cl, qdisc_peek_len(cl->qdisc));
1096 			if (cl->cl_flags & HFSC_FSC)
1097 				update_vf(cl, 0, cur_time);
1098 		}
1099 		sch_tree_unlock(sch);
1100 
1101 #ifdef CONFIG_NET_ESTIMATOR
1102 		if (tca[TCA_RATE-1])
1103 			gen_replace_estimator(&cl->bstats, &cl->rate_est,
1104 				cl->stats_lock, tca[TCA_RATE-1]);
1105 #endif
1106 		return 0;
1107 	}
1108 
1109 	if (parentid == TC_H_ROOT)
1110 		return -EEXIST;
1111 
1112 	parent = &q->root;
1113 	if (parentid) {
1114 		parent = hfsc_find_class(parentid, sch);
1115 		if (parent == NULL)
1116 			return -ENOENT;
1117 	}
1118 
1119 	if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1120 		return -EINVAL;
1121 	if (hfsc_find_class(classid, sch))
1122 		return -EEXIST;
1123 
1124 	if (rsc == NULL && fsc == NULL)
1125 		return -EINVAL;
1126 
1127 	cl = kmalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1128 	if (cl == NULL)
1129 		return -ENOBUFS;
1130 	memset(cl, 0, sizeof(struct hfsc_class));
1131 
1132 	if (rsc != NULL)
1133 		hfsc_change_rsc(cl, rsc, 0);
1134 	if (fsc != NULL)
1135 		hfsc_change_fsc(cl, fsc);
1136 	if (usc != NULL)
1137 		hfsc_change_usc(cl, usc, 0);
1138 
1139 	cl->refcnt    = 1;
1140 	cl->classid   = classid;
1141 	cl->sched     = q;
1142 	cl->cl_parent = parent;
1143 	cl->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1144 	if (cl->qdisc == NULL)
1145 		cl->qdisc = &noop_qdisc;
1146 	cl->stats_lock = &sch->dev->queue_lock;
1147 	INIT_LIST_HEAD(&cl->children);
1148 	cl->vt_tree = RB_ROOT;
1149 	cl->cf_tree = RB_ROOT;
1150 
1151 	sch_tree_lock(sch);
1152 	list_add_tail(&cl->hlist, &q->clhash[hfsc_hash(classid)]);
1153 	list_add_tail(&cl->siblings, &parent->children);
1154 	if (parent->level == 0)
1155 		hfsc_purge_queue(sch, parent);
1156 	hfsc_adjust_levels(parent);
1157 	cl->cl_pcvtoff = parent->cl_cvtoff;
1158 	sch_tree_unlock(sch);
1159 
1160 #ifdef CONFIG_NET_ESTIMATOR
1161 	if (tca[TCA_RATE-1])
1162 		gen_new_estimator(&cl->bstats, &cl->rate_est,
1163 			cl->stats_lock, tca[TCA_RATE-1]);
1164 #endif
1165 	*arg = (unsigned long)cl;
1166 	return 0;
1167 }
1168 
1169 static void
1170 hfsc_destroy_filters(struct tcf_proto **fl)
1171 {
1172 	struct tcf_proto *tp;
1173 
1174 	while ((tp = *fl) != NULL) {
1175 		*fl = tp->next;
1176 		tcf_destroy(tp);
1177 	}
1178 }
1179 
1180 static void
1181 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1182 {
1183 	struct hfsc_sched *q = qdisc_priv(sch);
1184 
1185 	hfsc_destroy_filters(&cl->filter_list);
1186 	qdisc_destroy(cl->qdisc);
1187 #ifdef CONFIG_NET_ESTIMATOR
1188 	gen_kill_estimator(&cl->bstats, &cl->rate_est);
1189 #endif
1190 	if (cl != &q->root)
1191 		kfree(cl);
1192 }
1193 
1194 static int
1195 hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1196 {
1197 	struct hfsc_sched *q = qdisc_priv(sch);
1198 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1199 
1200 	if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1201 		return -EBUSY;
1202 
1203 	sch_tree_lock(sch);
1204 
1205 	list_del(&cl->hlist);
1206 	list_del(&cl->siblings);
1207 	hfsc_adjust_levels(cl->cl_parent);
1208 	hfsc_purge_queue(sch, cl);
1209 	if (--cl->refcnt == 0)
1210 		hfsc_destroy_class(sch, cl);
1211 
1212 	sch_tree_unlock(sch);
1213 	return 0;
1214 }
1215 
1216 static struct hfsc_class *
1217 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1218 {
1219 	struct hfsc_sched *q = qdisc_priv(sch);
1220 	struct hfsc_class *cl;
1221 	struct tcf_result res;
1222 	struct tcf_proto *tcf;
1223 	int result;
1224 
1225 	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1226 	    (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1227 		if (cl->level == 0)
1228 			return cl;
1229 
1230 	*qerr = NET_XMIT_BYPASS;
1231 	tcf = q->root.filter_list;
1232 	while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
1233 #ifdef CONFIG_NET_CLS_ACT
1234 		switch (result) {
1235 		case TC_ACT_QUEUED:
1236 		case TC_ACT_STOLEN:
1237 			*qerr = NET_XMIT_SUCCESS;
1238 		case TC_ACT_SHOT:
1239 			return NULL;
1240 		}
1241 #elif defined(CONFIG_NET_CLS_POLICE)
1242 		if (result == TC_POLICE_SHOT)
1243 			return NULL;
1244 #endif
1245 		if ((cl = (struct hfsc_class *)res.class) == NULL) {
1246 			if ((cl = hfsc_find_class(res.classid, sch)) == NULL)
1247 				break; /* filter selected invalid classid */
1248 		}
1249 
1250 		if (cl->level == 0)
1251 			return cl; /* hit leaf class */
1252 
1253 		/* apply inner filter chain */
1254 		tcf = cl->filter_list;
1255 	}
1256 
1257 	/* classification failed, try default class */
1258 	cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1259 	if (cl == NULL || cl->level > 0)
1260 		return NULL;
1261 
1262 	return cl;
1263 }
1264 
1265 static int
1266 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1267                  struct Qdisc **old)
1268 {
1269 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1270 
1271 	if (cl == NULL)
1272 		return -ENOENT;
1273 	if (cl->level > 0)
1274 		return -EINVAL;
1275 	if (new == NULL) {
1276 		new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1277 		if (new == NULL)
1278 			new = &noop_qdisc;
1279 	}
1280 
1281 	sch_tree_lock(sch);
1282 	hfsc_purge_queue(sch, cl);
1283 	*old = xchg(&cl->qdisc, new);
1284 	sch_tree_unlock(sch);
1285 	return 0;
1286 }
1287 
1288 static struct Qdisc *
1289 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1290 {
1291 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1292 
1293 	if (cl != NULL && cl->level == 0)
1294 		return cl->qdisc;
1295 
1296 	return NULL;
1297 }
1298 
1299 static unsigned long
1300 hfsc_get_class(struct Qdisc *sch, u32 classid)
1301 {
1302 	struct hfsc_class *cl = hfsc_find_class(classid, sch);
1303 
1304 	if (cl != NULL)
1305 		cl->refcnt++;
1306 
1307 	return (unsigned long)cl;
1308 }
1309 
1310 static void
1311 hfsc_put_class(struct Qdisc *sch, unsigned long arg)
1312 {
1313 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1314 
1315 	if (--cl->refcnt == 0)
1316 		hfsc_destroy_class(sch, cl);
1317 }
1318 
1319 static unsigned long
1320 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1321 {
1322 	struct hfsc_class *p = (struct hfsc_class *)parent;
1323 	struct hfsc_class *cl = hfsc_find_class(classid, sch);
1324 
1325 	if (cl != NULL) {
1326 		if (p != NULL && p->level <= cl->level)
1327 			return 0;
1328 		cl->filter_cnt++;
1329 	}
1330 
1331 	return (unsigned long)cl;
1332 }
1333 
1334 static void
1335 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1336 {
1337 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1338 
1339 	cl->filter_cnt--;
1340 }
1341 
1342 static struct tcf_proto **
1343 hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg)
1344 {
1345 	struct hfsc_sched *q = qdisc_priv(sch);
1346 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1347 
1348 	if (cl == NULL)
1349 		cl = &q->root;
1350 
1351 	return &cl->filter_list;
1352 }
1353 
1354 static int
1355 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1356 {
1357 	struct tc_service_curve tsc;
1358 
1359 	tsc.m1 = sm2m(sc->sm1);
1360 	tsc.d  = dx2d(sc->dx);
1361 	tsc.m2 = sm2m(sc->sm2);
1362 	RTA_PUT(skb, attr, sizeof(tsc), &tsc);
1363 
1364 	return skb->len;
1365 
1366  rtattr_failure:
1367 	return -1;
1368 }
1369 
1370 static inline int
1371 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1372 {
1373 	if ((cl->cl_flags & HFSC_RSC) &&
1374 	    (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1375 		goto rtattr_failure;
1376 
1377 	if ((cl->cl_flags & HFSC_FSC) &&
1378 	    (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1379 		goto rtattr_failure;
1380 
1381 	if ((cl->cl_flags & HFSC_USC) &&
1382 	    (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1383 		goto rtattr_failure;
1384 
1385 	return skb->len;
1386 
1387  rtattr_failure:
1388 	return -1;
1389 }
1390 
1391 static int
1392 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1393                 struct tcmsg *tcm)
1394 {
1395 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1396 	unsigned char *b = skb->tail;
1397 	struct rtattr *rta = (struct rtattr *)b;
1398 
1399 	tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->classid : TC_H_ROOT;
1400 	tcm->tcm_handle = cl->classid;
1401 	if (cl->level == 0)
1402 		tcm->tcm_info = cl->qdisc->handle;
1403 
1404 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
1405 	if (hfsc_dump_curves(skb, cl) < 0)
1406 		goto rtattr_failure;
1407 	rta->rta_len = skb->tail - b;
1408 	return skb->len;
1409 
1410  rtattr_failure:
1411 	skb_trim(skb, b - skb->data);
1412 	return -1;
1413 }
1414 
1415 static int
1416 hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1417 	struct gnet_dump *d)
1418 {
1419 	struct hfsc_class *cl = (struct hfsc_class *)arg;
1420 	struct tc_hfsc_stats xstats;
1421 
1422 	cl->qstats.qlen = cl->qdisc->q.qlen;
1423 	xstats.level   = cl->level;
1424 	xstats.period  = cl->cl_vtperiod;
1425 	xstats.work    = cl->cl_total;
1426 	xstats.rtwork  = cl->cl_cumul;
1427 
1428 	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
1429 #ifdef CONFIG_NET_ESTIMATOR
1430 	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1431 #endif
1432 	    gnet_stats_copy_queue(d, &cl->qstats) < 0)
1433 		return -1;
1434 
1435 	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1436 }
1437 
1438 
1439 
1440 static void
1441 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1442 {
1443 	struct hfsc_sched *q = qdisc_priv(sch);
1444 	struct hfsc_class *cl;
1445 	unsigned int i;
1446 
1447 	if (arg->stop)
1448 		return;
1449 
1450 	for (i = 0; i < HFSC_HSIZE; i++) {
1451 		list_for_each_entry(cl, &q->clhash[i], hlist) {
1452 			if (arg->count < arg->skip) {
1453 				arg->count++;
1454 				continue;
1455 			}
1456 			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1457 				arg->stop = 1;
1458 				return;
1459 			}
1460 			arg->count++;
1461 		}
1462 	}
1463 }
1464 
1465 static void
1466 hfsc_watchdog(unsigned long arg)
1467 {
1468 	struct Qdisc *sch = (struct Qdisc *)arg;
1469 
1470 	sch->flags &= ~TCQ_F_THROTTLED;
1471 	netif_schedule(sch->dev);
1472 }
1473 
1474 static void
1475 hfsc_schedule_watchdog(struct Qdisc *sch, u64 cur_time)
1476 {
1477 	struct hfsc_sched *q = qdisc_priv(sch);
1478 	struct hfsc_class *cl;
1479 	u64 next_time = 0;
1480 	long delay;
1481 
1482 	if ((cl = eltree_get_minel(q)) != NULL)
1483 		next_time = cl->cl_e;
1484 	if (q->root.cl_cfmin != 0) {
1485 		if (next_time == 0 || next_time > q->root.cl_cfmin)
1486 			next_time = q->root.cl_cfmin;
1487 	}
1488 	ASSERT(next_time != 0);
1489 	delay = next_time - cur_time;
1490 	delay = PSCHED_US2JIFFIE(delay);
1491 
1492 	sch->flags |= TCQ_F_THROTTLED;
1493 	mod_timer(&q->wd_timer, jiffies + delay);
1494 }
1495 
1496 static int
1497 hfsc_init_qdisc(struct Qdisc *sch, struct rtattr *opt)
1498 {
1499 	struct hfsc_sched *q = qdisc_priv(sch);
1500 	struct tc_hfsc_qopt *qopt;
1501 	unsigned int i;
1502 
1503 	if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
1504 		return -EINVAL;
1505 	qopt = RTA_DATA(opt);
1506 
1507 	sch->stats_lock = &sch->dev->queue_lock;
1508 
1509 	q->defcls = qopt->defcls;
1510 	for (i = 0; i < HFSC_HSIZE; i++)
1511 		INIT_LIST_HEAD(&q->clhash[i]);
1512 	q->eligible = RB_ROOT;
1513 	INIT_LIST_HEAD(&q->droplist);
1514 	skb_queue_head_init(&q->requeue);
1515 
1516 	q->root.refcnt  = 1;
1517 	q->root.classid = sch->handle;
1518 	q->root.sched   = q;
1519 	q->root.qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1520 	if (q->root.qdisc == NULL)
1521 		q->root.qdisc = &noop_qdisc;
1522 	q->root.stats_lock = &sch->dev->queue_lock;
1523 	INIT_LIST_HEAD(&q->root.children);
1524 	q->root.vt_tree = RB_ROOT;
1525 	q->root.cf_tree = RB_ROOT;
1526 
1527 	list_add(&q->root.hlist, &q->clhash[hfsc_hash(q->root.classid)]);
1528 
1529 	init_timer(&q->wd_timer);
1530 	q->wd_timer.function = hfsc_watchdog;
1531 	q->wd_timer.data = (unsigned long)sch;
1532 
1533 	return 0;
1534 }
1535 
1536 static int
1537 hfsc_change_qdisc(struct Qdisc *sch, struct rtattr *opt)
1538 {
1539 	struct hfsc_sched *q = qdisc_priv(sch);
1540 	struct tc_hfsc_qopt *qopt;
1541 
1542 	if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
1543 		return -EINVAL;
1544 	qopt = RTA_DATA(opt);
1545 
1546 	sch_tree_lock(sch);
1547 	q->defcls = qopt->defcls;
1548 	sch_tree_unlock(sch);
1549 
1550 	return 0;
1551 }
1552 
1553 static void
1554 hfsc_reset_class(struct hfsc_class *cl)
1555 {
1556 	cl->cl_total        = 0;
1557 	cl->cl_cumul        = 0;
1558 	cl->cl_d            = 0;
1559 	cl->cl_e            = 0;
1560 	cl->cl_vt           = 0;
1561 	cl->cl_vtadj        = 0;
1562 	cl->cl_vtoff        = 0;
1563 	cl->cl_cvtmin       = 0;
1564 	cl->cl_cvtmax       = 0;
1565 	cl->cl_cvtoff       = 0;
1566 	cl->cl_pcvtoff      = 0;
1567 	cl->cl_vtperiod     = 0;
1568 	cl->cl_parentperiod = 0;
1569 	cl->cl_f            = 0;
1570 	cl->cl_myf          = 0;
1571 	cl->cl_myfadj       = 0;
1572 	cl->cl_cfmin        = 0;
1573 	cl->cl_nactive      = 0;
1574 
1575 	cl->vt_tree = RB_ROOT;
1576 	cl->cf_tree = RB_ROOT;
1577 	qdisc_reset(cl->qdisc);
1578 
1579 	if (cl->cl_flags & HFSC_RSC)
1580 		rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1581 	if (cl->cl_flags & HFSC_FSC)
1582 		rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1583 	if (cl->cl_flags & HFSC_USC)
1584 		rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1585 }
1586 
1587 static void
1588 hfsc_reset_qdisc(struct Qdisc *sch)
1589 {
1590 	struct hfsc_sched *q = qdisc_priv(sch);
1591 	struct hfsc_class *cl;
1592 	unsigned int i;
1593 
1594 	for (i = 0; i < HFSC_HSIZE; i++) {
1595 		list_for_each_entry(cl, &q->clhash[i], hlist)
1596 			hfsc_reset_class(cl);
1597 	}
1598 	__skb_queue_purge(&q->requeue);
1599 	q->eligible = RB_ROOT;
1600 	INIT_LIST_HEAD(&q->droplist);
1601 	del_timer(&q->wd_timer);
1602 	sch->flags &= ~TCQ_F_THROTTLED;
1603 	sch->q.qlen = 0;
1604 }
1605 
1606 static void
1607 hfsc_destroy_qdisc(struct Qdisc *sch)
1608 {
1609 	struct hfsc_sched *q = qdisc_priv(sch);
1610 	struct hfsc_class *cl, *next;
1611 	unsigned int i;
1612 
1613 	for (i = 0; i < HFSC_HSIZE; i++) {
1614 		list_for_each_entry_safe(cl, next, &q->clhash[i], hlist)
1615 			hfsc_destroy_class(sch, cl);
1616 	}
1617 	__skb_queue_purge(&q->requeue);
1618 	del_timer(&q->wd_timer);
1619 }
1620 
1621 static int
1622 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1623 {
1624 	struct hfsc_sched *q = qdisc_priv(sch);
1625 	unsigned char *b = skb->tail;
1626 	struct tc_hfsc_qopt qopt;
1627 
1628 	qopt.defcls = q->defcls;
1629 	RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);
1630 	return skb->len;
1631 
1632  rtattr_failure:
1633 	skb_trim(skb, b - skb->data);
1634 	return -1;
1635 }
1636 
1637 static int
1638 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
1639 {
1640 	struct hfsc_class *cl;
1641 	unsigned int len;
1642 	int err;
1643 
1644 	cl = hfsc_classify(skb, sch, &err);
1645 	if (cl == NULL) {
1646 		if (err == NET_XMIT_BYPASS)
1647 			sch->qstats.drops++;
1648 		kfree_skb(skb);
1649 		return err;
1650 	}
1651 
1652 	len = skb->len;
1653 	err = cl->qdisc->enqueue(skb, cl->qdisc);
1654 	if (unlikely(err != NET_XMIT_SUCCESS)) {
1655 		cl->qstats.drops++;
1656 		sch->qstats.drops++;
1657 		return err;
1658 	}
1659 
1660 	if (cl->qdisc->q.qlen == 1)
1661 		set_active(cl, len);
1662 
1663 	cl->bstats.packets++;
1664 	cl->bstats.bytes += len;
1665 	sch->bstats.packets++;
1666 	sch->bstats.bytes += len;
1667 	sch->q.qlen++;
1668 
1669 	return NET_XMIT_SUCCESS;
1670 }
1671 
1672 static struct sk_buff *
1673 hfsc_dequeue(struct Qdisc *sch)
1674 {
1675 	struct hfsc_sched *q = qdisc_priv(sch);
1676 	struct hfsc_class *cl;
1677 	struct sk_buff *skb;
1678 	u64 cur_time;
1679 	unsigned int next_len;
1680 	int realtime = 0;
1681 
1682 	if (sch->q.qlen == 0)
1683 		return NULL;
1684 	if ((skb = __skb_dequeue(&q->requeue)))
1685 		goto out;
1686 
1687 	PSCHED_GET_TIME(cur_time);
1688 
1689 	/*
1690 	 * if there are eligible classes, use real-time criteria.
1691 	 * find the class with the minimum deadline among
1692 	 * the eligible classes.
1693 	 */
1694 	if ((cl = eltree_get_mindl(q, cur_time)) != NULL) {
1695 		realtime = 1;
1696 	} else {
1697 		/*
1698 		 * use link-sharing criteria
1699 		 * get the class with the minimum vt in the hierarchy
1700 		 */
1701 		cl = vttree_get_minvt(&q->root, cur_time);
1702 		if (cl == NULL) {
1703 			sch->qstats.overlimits++;
1704 			hfsc_schedule_watchdog(sch, cur_time);
1705 			return NULL;
1706 		}
1707 	}
1708 
1709 	skb = cl->qdisc->dequeue(cl->qdisc);
1710 	if (skb == NULL) {
1711 		if (net_ratelimit())
1712 			printk("HFSC: Non-work-conserving qdisc ?\n");
1713 		return NULL;
1714 	}
1715 
1716 	update_vf(cl, skb->len, cur_time);
1717 	if (realtime)
1718 		cl->cl_cumul += skb->len;
1719 
1720 	if (cl->qdisc->q.qlen != 0) {
1721 		if (cl->cl_flags & HFSC_RSC) {
1722 			/* update ed */
1723 			next_len = qdisc_peek_len(cl->qdisc);
1724 			if (realtime)
1725 				update_ed(cl, next_len);
1726 			else
1727 				update_d(cl, next_len);
1728 		}
1729 	} else {
1730 		/* the class becomes passive */
1731 		set_passive(cl);
1732 	}
1733 
1734  out:
1735 	sch->flags &= ~TCQ_F_THROTTLED;
1736 	sch->q.qlen--;
1737 
1738 	return skb;
1739 }
1740 
1741 static int
1742 hfsc_requeue(struct sk_buff *skb, struct Qdisc *sch)
1743 {
1744 	struct hfsc_sched *q = qdisc_priv(sch);
1745 
1746 	__skb_queue_head(&q->requeue, skb);
1747 	sch->q.qlen++;
1748 	sch->qstats.requeues++;
1749 	return NET_XMIT_SUCCESS;
1750 }
1751 
1752 static unsigned int
1753 hfsc_drop(struct Qdisc *sch)
1754 {
1755 	struct hfsc_sched *q = qdisc_priv(sch);
1756 	struct hfsc_class *cl;
1757 	unsigned int len;
1758 
1759 	list_for_each_entry(cl, &q->droplist, dlist) {
1760 		if (cl->qdisc->ops->drop != NULL &&
1761 		    (len = cl->qdisc->ops->drop(cl->qdisc)) > 0) {
1762 			if (cl->qdisc->q.qlen == 0) {
1763 				update_vf(cl, 0, 0);
1764 				set_passive(cl);
1765 			} else {
1766 				list_move_tail(&cl->dlist, &q->droplist);
1767 			}
1768 			cl->qstats.drops++;
1769 			sch->qstats.drops++;
1770 			sch->q.qlen--;
1771 			return len;
1772 		}
1773 	}
1774 	return 0;
1775 }
1776 
1777 static struct Qdisc_class_ops hfsc_class_ops = {
1778 	.change		= hfsc_change_class,
1779 	.delete		= hfsc_delete_class,
1780 	.graft		= hfsc_graft_class,
1781 	.leaf		= hfsc_class_leaf,
1782 	.get		= hfsc_get_class,
1783 	.put		= hfsc_put_class,
1784 	.bind_tcf	= hfsc_bind_tcf,
1785 	.unbind_tcf	= hfsc_unbind_tcf,
1786 	.tcf_chain	= hfsc_tcf_chain,
1787 	.dump		= hfsc_dump_class,
1788 	.dump_stats	= hfsc_dump_class_stats,
1789 	.walk		= hfsc_walk
1790 };
1791 
1792 static struct Qdisc_ops hfsc_qdisc_ops = {
1793 	.id		= "hfsc",
1794 	.init		= hfsc_init_qdisc,
1795 	.change		= hfsc_change_qdisc,
1796 	.reset		= hfsc_reset_qdisc,
1797 	.destroy	= hfsc_destroy_qdisc,
1798 	.dump		= hfsc_dump_qdisc,
1799 	.enqueue	= hfsc_enqueue,
1800 	.dequeue	= hfsc_dequeue,
1801 	.requeue	= hfsc_requeue,
1802 	.drop		= hfsc_drop,
1803 	.cl_ops		= &hfsc_class_ops,
1804 	.priv_size	= sizeof(struct hfsc_sched),
1805 	.owner		= THIS_MODULE
1806 };
1807 
1808 static int __init
1809 hfsc_init(void)
1810 {
1811 	return register_qdisc(&hfsc_qdisc_ops);
1812 }
1813 
1814 static void __exit
1815 hfsc_cleanup(void)
1816 {
1817 	unregister_qdisc(&hfsc_qdisc_ops);
1818 }
1819 
1820 MODULE_LICENSE("GPL");
1821 module_init(hfsc_init);
1822 module_exit(hfsc_cleanup);
1823