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 const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
 907	[TCA_HFSC_RSC]	= { .len = sizeof(struct tc_service_curve) },
 908	[TCA_HFSC_FSC]	= { .len = sizeof(struct tc_service_curve) },
 909	[TCA_HFSC_USC]	= { .len = sizeof(struct tc_service_curve) },
 910};
 911
 912static int
 913hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 914		  struct nlattr **tca, unsigned long *arg,
 915		  struct netlink_ext_ack *extack)
 916{
 917	struct hfsc_sched *q = qdisc_priv(sch);
 918	struct hfsc_class *cl = (struct hfsc_class *)*arg;
 919	struct hfsc_class *parent = NULL;
 920	struct nlattr *opt = tca[TCA_OPTIONS];
 921	struct nlattr *tb[TCA_HFSC_MAX + 1];
 922	struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
 923	u64 cur_time;
 924	int err;
 925
 926	if (opt == NULL)
 927		return -EINVAL;
 928
 929	err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
 930					  NULL);
 931	if (err < 0)
 932		return err;
 933
 934	if (tb[TCA_HFSC_RSC]) {
 935		rsc = nla_data(tb[TCA_HFSC_RSC]);
 936		if (rsc->m1 == 0 && rsc->m2 == 0)
 937			rsc = NULL;
 938	}
 939
 940	if (tb[TCA_HFSC_FSC]) {
 941		fsc = nla_data(tb[TCA_HFSC_FSC]);
 942		if (fsc->m1 == 0 && fsc->m2 == 0)
 943			fsc = NULL;
 944	}
 945
 946	if (tb[TCA_HFSC_USC]) {
 947		usc = nla_data(tb[TCA_HFSC_USC]);
 948		if (usc->m1 == 0 && usc->m2 == 0)
 949			usc = NULL;
 950	}
 951
 952	if (cl != NULL) {
 953		int old_flags;
 954
 955		if (parentid) {
 956			if (cl->cl_parent &&
 957			    cl->cl_parent->cl_common.classid != parentid)
 958				return -EINVAL;
 959			if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
 960				return -EINVAL;
 961		}
 962		cur_time = psched_get_time();
 963
 964		if (tca[TCA_RATE]) {
 965			err = gen_replace_estimator(&cl->bstats, NULL,
 966						    &cl->rate_est,
 967						    NULL,
 968						    qdisc_root_sleeping_running(sch),
 969						    tca[TCA_RATE]);
 970			if (err)
 971				return err;
 972		}
 973
 974		sch_tree_lock(sch);
 975		old_flags = cl->cl_flags;
 976
 977		if (rsc != NULL)
 978			hfsc_change_rsc(cl, rsc, cur_time);
 979		if (fsc != NULL)
 980			hfsc_change_fsc(cl, fsc);
 981		if (usc != NULL)
 982			hfsc_change_usc(cl, usc, cur_time);
 983
 984		if (cl->qdisc->q.qlen != 0) {
 985			int len = qdisc_peek_len(cl->qdisc);
 986
 987			if (cl->cl_flags & HFSC_RSC) {
 988				if (old_flags & HFSC_RSC)
 989					update_ed(cl, len);
 990				else
 991					init_ed(cl, len);
 992			}
 993
 994			if (cl->cl_flags & HFSC_FSC) {
 995				if (old_flags & HFSC_FSC)
 996					update_vf(cl, 0, cur_time);
 997				else
 998					init_vf(cl, len);
 999			}
1000		}
1001		sch_tree_unlock(sch);
1002
1003		return 0;
1004	}
1005
1006	if (parentid == TC_H_ROOT)
1007		return -EEXIST;
1008
1009	parent = &q->root;
1010	if (parentid) {
1011		parent = hfsc_find_class(parentid, sch);
1012		if (parent == NULL)
1013			return -ENOENT;
1014	}
1015
1016	if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1017		return -EINVAL;
1018	if (hfsc_find_class(classid, sch))
1019		return -EEXIST;
1020
1021	if (rsc == NULL && fsc == NULL)
1022		return -EINVAL;
1023
1024	cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1025	if (cl == NULL)
1026		return -ENOBUFS;
1027
1028	err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1029	if (err) {
1030		kfree(cl);
1031		return err;
1032	}
1033
1034	if (tca[TCA_RATE]) {
1035		err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1036					NULL,
1037					qdisc_root_sleeping_running(sch),
1038					tca[TCA_RATE]);
1039		if (err) {
1040			tcf_block_put(cl->block);
1041			kfree(cl);
1042			return err;
1043		}
1044	}
1045
1046	if (rsc != NULL)
1047		hfsc_change_rsc(cl, rsc, 0);
1048	if (fsc != NULL)
1049		hfsc_change_fsc(cl, fsc);
1050	if (usc != NULL)
1051		hfsc_change_usc(cl, usc, 0);
1052
1053	cl->cl_common.classid = classid;
1054	cl->sched     = q;
1055	cl->cl_parent = parent;
1056	cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1057				      classid, NULL);
1058	if (cl->qdisc == NULL)
1059		cl->qdisc = &noop_qdisc;
1060	else
1061		qdisc_hash_add(cl->qdisc, true);
1062	INIT_LIST_HEAD(&cl->children);
1063	cl->vt_tree = RB_ROOT;
1064	cl->cf_tree = RB_ROOT;
1065
1066	sch_tree_lock(sch);
1067	qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1068	list_add_tail(&cl->siblings, &parent->children);
1069	if (parent->level == 0)
1070		qdisc_purge_queue(parent->qdisc);
1071	hfsc_adjust_levels(parent);
1072	sch_tree_unlock(sch);
1073
1074	qdisc_class_hash_grow(sch, &q->clhash);
1075
1076	*arg = (unsigned long)cl;
1077	return 0;
1078}
1079
1080static void
1081hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1082{
1083	struct hfsc_sched *q = qdisc_priv(sch);
1084
1085	tcf_block_put(cl->block);
1086	qdisc_put(cl->qdisc);
1087	gen_kill_estimator(&cl->rate_est);
1088	if (cl != &q->root)
1089		kfree(cl);
1090}
1091
1092static int
1093hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1094{
1095	struct hfsc_sched *q = qdisc_priv(sch);
1096	struct hfsc_class *cl = (struct hfsc_class *)arg;
1097
1098	if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1099		return -EBUSY;
1100
1101	sch_tree_lock(sch);
1102
1103	list_del(&cl->siblings);
1104	hfsc_adjust_levels(cl->cl_parent);
1105
1106	qdisc_purge_queue(cl->qdisc);
1107	qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1108
1109	sch_tree_unlock(sch);
1110
1111	hfsc_destroy_class(sch, cl);
1112	return 0;
1113}
1114
1115static struct hfsc_class *
1116hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1117{
1118	struct hfsc_sched *q = qdisc_priv(sch);
1119	struct hfsc_class *head, *cl;
1120	struct tcf_result res;
1121	struct tcf_proto *tcf;
1122	int result;
1123
1124	if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1125	    (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1126		if (cl->level == 0)
1127			return cl;
1128
1129	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1130	head = &q->root;
1131	tcf = rcu_dereference_bh(q->root.filter_list);
1132	while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
1133#ifdef CONFIG_NET_CLS_ACT
1134		switch (result) {
1135		case TC_ACT_QUEUED:
1136		case TC_ACT_STOLEN:
1137		case TC_ACT_TRAP:
1138			*qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1139			fallthrough;
1140		case TC_ACT_SHOT:
1141			return NULL;
1142		}
1143#endif
1144		cl = (struct hfsc_class *)res.class;
1145		if (!cl) {
1146			cl = hfsc_find_class(res.classid, sch);
1147			if (!cl)
1148				break; /* filter selected invalid classid */
1149			if (cl->level >= head->level)
1150				break; /* filter may only point downwards */
1151		}
1152
1153		if (cl->level == 0)
1154			return cl; /* hit leaf class */
1155
1156		/* apply inner filter chain */
1157		tcf = rcu_dereference_bh(cl->filter_list);
1158		head = cl;
1159	}
1160
1161	/* classification failed, try default class */
1162	cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1163	if (cl == NULL || cl->level > 0)
1164		return NULL;
1165
1166	return cl;
1167}
1168
1169static int
1170hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1171		 struct Qdisc **old, struct netlink_ext_ack *extack)
1172{
1173	struct hfsc_class *cl = (struct hfsc_class *)arg;
1174
1175	if (cl->level > 0)
1176		return -EINVAL;
1177	if (new == NULL) {
1178		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1179					cl->cl_common.classid, NULL);
1180		if (new == NULL)
1181			new = &noop_qdisc;
1182	}
1183
1184	*old = qdisc_replace(sch, new, &cl->qdisc);
1185	return 0;
1186}
1187
1188static struct Qdisc *
1189hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1190{
1191	struct hfsc_class *cl = (struct hfsc_class *)arg;
1192
1193	if (cl->level == 0)
1194		return cl->qdisc;
1195
1196	return NULL;
1197}
1198
1199static void
1200hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1201{
1202	struct hfsc_class *cl = (struct hfsc_class *)arg;
1203
1204	/* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
1205	 * needs to be called explicitly to remove a class from vttree.
1206	 */
1207	update_vf(cl, 0, 0);
1208	if (cl->cl_flags & HFSC_RSC)
1209		eltree_remove(cl);
1210}
1211
1212static unsigned long
1213hfsc_search_class(struct Qdisc *sch, u32 classid)
1214{
1215	return (unsigned long)hfsc_find_class(classid, sch);
1216}
1217
1218static unsigned long
1219hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1220{
1221	struct hfsc_class *p = (struct hfsc_class *)parent;
1222	struct hfsc_class *cl = hfsc_find_class(classid, sch);
1223
1224	if (cl != NULL) {
1225		if (p != NULL && p->level <= cl->level)
1226			return 0;
1227		cl->filter_cnt++;
1228	}
1229
1230	return (unsigned long)cl;
1231}
1232
1233static void
1234hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1235{
1236	struct hfsc_class *cl = (struct hfsc_class *)arg;
1237
1238	cl->filter_cnt--;
1239}
1240
1241static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
1242					struct netlink_ext_ack *extack)
1243{
1244	struct hfsc_sched *q = qdisc_priv(sch);
1245	struct hfsc_class *cl = (struct hfsc_class *)arg;
1246
1247	if (cl == NULL)
1248		cl = &q->root;
1249
1250	return cl->block;
1251}
1252
1253static int
1254hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1255{
1256	struct tc_service_curve tsc;
1257
1258	tsc.m1 = sm2m(sc->sm1);
1259	tsc.d  = dx2d(sc->dx);
1260	tsc.m2 = sm2m(sc->sm2);
1261	if (nla_put(skb, attr, sizeof(tsc), &tsc))
1262		goto nla_put_failure;
1263
1264	return skb->len;
1265
1266 nla_put_failure:
1267	return -1;
1268}
1269
1270static int
1271hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1272{
1273	if ((cl->cl_flags & HFSC_RSC) &&
1274	    (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1275		goto nla_put_failure;
1276
1277	if ((cl->cl_flags & HFSC_FSC) &&
1278	    (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1279		goto nla_put_failure;
1280
1281	if ((cl->cl_flags & HFSC_USC) &&
1282	    (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1283		goto nla_put_failure;
1284
1285	return skb->len;
1286
1287 nla_put_failure:
1288	return -1;
1289}
1290
1291static int
1292hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1293		struct tcmsg *tcm)
1294{
1295	struct hfsc_class *cl = (struct hfsc_class *)arg;
1296	struct nlattr *nest;
1297
1298	tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1299					  TC_H_ROOT;
1300	tcm->tcm_handle = cl->cl_common.classid;
1301	if (cl->level == 0)
1302		tcm->tcm_info = cl->qdisc->handle;
1303
1304	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1305	if (nest == NULL)
1306		goto nla_put_failure;
1307	if (hfsc_dump_curves(skb, cl) < 0)
1308		goto nla_put_failure;
1309	return nla_nest_end(skb, nest);
1310
1311 nla_put_failure:
1312	nla_nest_cancel(skb, nest);
1313	return -EMSGSIZE;
1314}
1315
1316static int
1317hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1318	struct gnet_dump *d)
1319{
1320	struct hfsc_class *cl = (struct hfsc_class *)arg;
1321	struct tc_hfsc_stats xstats;
1322	__u32 qlen;
1323
1324	qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
1325	xstats.level   = cl->level;
1326	xstats.period  = cl->cl_vtperiod;
1327	xstats.work    = cl->cl_total;
1328	xstats.rtwork  = cl->cl_cumul;
1329
1330	if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d, NULL, &cl->bstats) < 0 ||
1331	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1332	    gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1333		return -1;
1334
1335	return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1336}
1337
1338
1339
1340static void
1341hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1342{
1343	struct hfsc_sched *q = qdisc_priv(sch);
1344	struct hfsc_class *cl;
1345	unsigned int i;
1346
1347	if (arg->stop)
1348		return;
1349
1350	for (i = 0; i < q->clhash.hashsize; i++) {
1351		hlist_for_each_entry(cl, &q->clhash.hash[i],
1352				     cl_common.hnode) {
1353			if (arg->count < arg->skip) {
1354				arg->count++;
1355				continue;
1356			}
1357			if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1358				arg->stop = 1;
1359				return;
1360			}
1361			arg->count++;
1362		}
1363	}
1364}
1365
1366static void
1367hfsc_schedule_watchdog(struct Qdisc *sch)
1368{
1369	struct hfsc_sched *q = qdisc_priv(sch);
1370	struct hfsc_class *cl;
1371	u64 next_time = 0;
1372
1373	cl = eltree_get_minel(q);
1374	if (cl)
1375		next_time = cl->cl_e;
1376	if (q->root.cl_cfmin != 0) {
1377		if (next_time == 0 || next_time > q->root.cl_cfmin)
1378			next_time = q->root.cl_cfmin;
1379	}
1380	if (next_time)
1381		qdisc_watchdog_schedule(&q->watchdog, next_time);
1382}
1383
1384static int
1385hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
1386		struct netlink_ext_ack *extack)
1387{
1388	struct hfsc_sched *q = qdisc_priv(sch);
1389	struct tc_hfsc_qopt *qopt;
1390	int err;
1391
1392	qdisc_watchdog_init(&q->watchdog, sch);
1393
1394	if (!opt || nla_len(opt) < sizeof(*qopt))
1395		return -EINVAL;
1396	qopt = nla_data(opt);
1397
1398	q->defcls = qopt->defcls;
1399	err = qdisc_class_hash_init(&q->clhash);
1400	if (err < 0)
1401		return err;
1402	q->eligible = RB_ROOT;
1403
1404	err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
1405	if (err)
1406		return err;
1407
1408	q->root.cl_common.classid = sch->handle;
1409	q->root.sched   = q;
1410	q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1411					  sch->handle, NULL);
1412	if (q->root.qdisc == NULL)
1413		q->root.qdisc = &noop_qdisc;
1414	else
1415		qdisc_hash_add(q->root.qdisc, true);
1416	INIT_LIST_HEAD(&q->root.children);
1417	q->root.vt_tree = RB_ROOT;
1418	q->root.cf_tree = RB_ROOT;
1419
1420	qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1421	qdisc_class_hash_grow(sch, &q->clhash);
1422
1423	return 0;
1424}
1425
1426static int
1427hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
1428		  struct netlink_ext_ack *extack)
1429{
1430	struct hfsc_sched *q = qdisc_priv(sch);
1431	struct tc_hfsc_qopt *qopt;
1432
1433	if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1434		return -EINVAL;
1435	qopt = nla_data(opt);
1436
1437	sch_tree_lock(sch);
1438	q->defcls = qopt->defcls;
1439	sch_tree_unlock(sch);
1440
1441	return 0;
1442}
1443
1444static void
1445hfsc_reset_class(struct hfsc_class *cl)
1446{
1447	cl->cl_total        = 0;
1448	cl->cl_cumul        = 0;
1449	cl->cl_d            = 0;
1450	cl->cl_e            = 0;
1451	cl->cl_vt           = 0;
1452	cl->cl_vtadj        = 0;
1453	cl->cl_cvtmin       = 0;
1454	cl->cl_cvtoff       = 0;
1455	cl->cl_vtperiod     = 0;
1456	cl->cl_parentperiod = 0;
1457	cl->cl_f            = 0;
1458	cl->cl_myf          = 0;
1459	cl->cl_cfmin        = 0;
1460	cl->cl_nactive      = 0;
1461
1462	cl->vt_tree = RB_ROOT;
1463	cl->cf_tree = RB_ROOT;
1464	qdisc_reset(cl->qdisc);
1465
1466	if (cl->cl_flags & HFSC_RSC)
1467		rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1468	if (cl->cl_flags & HFSC_FSC)
1469		rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1470	if (cl->cl_flags & HFSC_USC)
1471		rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1472}
1473
1474static void
1475hfsc_reset_qdisc(struct Qdisc *sch)
1476{
1477	struct hfsc_sched *q = qdisc_priv(sch);
1478	struct hfsc_class *cl;
1479	unsigned int i;
1480
1481	for (i = 0; i < q->clhash.hashsize; i++) {
1482		hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1483			hfsc_reset_class(cl);
1484	}
1485	q->eligible = RB_ROOT;
1486	qdisc_watchdog_cancel(&q->watchdog);
1487	sch->qstats.backlog = 0;
1488	sch->q.qlen = 0;
1489}
1490
1491static void
1492hfsc_destroy_qdisc(struct Qdisc *sch)
1493{
1494	struct hfsc_sched *q = qdisc_priv(sch);
1495	struct hlist_node *next;
1496	struct hfsc_class *cl;
1497	unsigned int i;
1498
1499	for (i = 0; i < q->clhash.hashsize; i++) {
1500		hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
1501			tcf_block_put(cl->block);
1502			cl->block = NULL;
1503		}
1504	}
1505	for (i = 0; i < q->clhash.hashsize; i++) {
1506		hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1507					  cl_common.hnode)
1508			hfsc_destroy_class(sch, cl);
1509	}
1510	qdisc_class_hash_destroy(&q->clhash);
1511	qdisc_watchdog_cancel(&q->watchdog);
1512}
1513
1514static int
1515hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1516{
1517	struct hfsc_sched *q = qdisc_priv(sch);
1518	unsigned char *b = skb_tail_pointer(skb);
1519	struct tc_hfsc_qopt qopt;
1520
1521	qopt.defcls = q->defcls;
1522	if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1523		goto nla_put_failure;
1524	return skb->len;
1525
1526 nla_put_failure:
1527	nlmsg_trim(skb, b);
1528	return -1;
1529}
1530
1531static int
1532hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
1533{
1534	unsigned int len = qdisc_pkt_len(skb);
1535	struct hfsc_class *cl;
1536	int err;
1537	bool first;
1538
1539	cl = hfsc_classify(skb, sch, &err);
1540	if (cl == NULL) {
1541		if (err & __NET_XMIT_BYPASS)
1542			qdisc_qstats_drop(sch);
1543		__qdisc_drop(skb, to_free);
1544		return err;
1545	}
1546
1547	first = !cl->qdisc->q.qlen;
1548	err = qdisc_enqueue(skb, cl->qdisc, to_free);
1549	if (unlikely(err != NET_XMIT_SUCCESS)) {
1550		if (net_xmit_drop_count(err)) {
1551			cl->qstats.drops++;
1552			qdisc_qstats_drop(sch);
1553		}
1554		return err;
1555	}
1556
1557	if (first) {
1558		if (cl->cl_flags & HFSC_RSC)
1559			init_ed(cl, len);
1560		if (cl->cl_flags & HFSC_FSC)
1561			init_vf(cl, len);
1562		/*
1563		 * If this is the first packet, isolate the head so an eventual
1564		 * head drop before the first dequeue operation has no chance
1565		 * to invalidate the deadline.
1566		 */
1567		if (cl->cl_flags & HFSC_RSC)
1568			cl->qdisc->ops->peek(cl->qdisc);
1569
1570	}
1571
1572	sch->qstats.backlog += len;
1573	sch->q.qlen++;
1574
1575	return NET_XMIT_SUCCESS;
1576}
1577
1578static struct sk_buff *
1579hfsc_dequeue(struct Qdisc *sch)
1580{
1581	struct hfsc_sched *q = qdisc_priv(sch);
1582	struct hfsc_class *cl;
1583	struct sk_buff *skb;
1584	u64 cur_time;
1585	unsigned int next_len;
1586	int realtime = 0;
1587
1588	if (sch->q.qlen == 0)
1589		return NULL;
1590
1591	cur_time = psched_get_time();
1592
1593	/*
1594	 * if there are eligible classes, use real-time criteria.
1595	 * find the class with the minimum deadline among
1596	 * the eligible classes.
1597	 */
1598	cl = eltree_get_mindl(q, cur_time);
1599	if (cl) {
1600		realtime = 1;
1601	} else {
1602		/*
1603		 * use link-sharing criteria
1604		 * get the class with the minimum vt in the hierarchy
1605		 */
1606		cl = vttree_get_minvt(&q->root, cur_time);
1607		if (cl == NULL) {
1608			qdisc_qstats_overlimit(sch);
1609			hfsc_schedule_watchdog(sch);
1610			return NULL;
1611		}
1612	}
1613
1614	skb = qdisc_dequeue_peeked(cl->qdisc);
1615	if (skb == NULL) {
1616		qdisc_warn_nonwc("HFSC", cl->qdisc);
1617		return NULL;
1618	}
1619
1620	bstats_update(&cl->bstats, skb);
1621	update_vf(cl, qdisc_pkt_len(skb), cur_time);
1622	if (realtime)
1623		cl->cl_cumul += qdisc_pkt_len(skb);
1624
1625	if (cl->cl_flags & HFSC_RSC) {
1626		if (cl->qdisc->q.qlen != 0) {
1627			/* update ed */
1628			next_len = qdisc_peek_len(cl->qdisc);
1629			if (realtime)
1630				update_ed(cl, next_len);
1631			else
1632				update_d(cl, next_len);
1633		} else {
1634			/* the class becomes passive */
1635			eltree_remove(cl);
1636		}
1637	}
1638
1639	qdisc_bstats_update(sch, skb);
1640	qdisc_qstats_backlog_dec(sch, skb);
1641	sch->q.qlen--;
1642
1643	return skb;
1644}
1645
1646static const struct Qdisc_class_ops hfsc_class_ops = {
1647	.change		= hfsc_change_class,
1648	.delete		= hfsc_delete_class,
1649	.graft		= hfsc_graft_class,
1650	.leaf		= hfsc_class_leaf,
1651	.qlen_notify	= hfsc_qlen_notify,
1652	.find		= hfsc_search_class,
1653	.bind_tcf	= hfsc_bind_tcf,
1654	.unbind_tcf	= hfsc_unbind_tcf,
1655	.tcf_block	= hfsc_tcf_block,
1656	.dump		= hfsc_dump_class,
1657	.dump_stats	= hfsc_dump_class_stats,
1658	.walk		= hfsc_walk
1659};
1660
1661static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1662	.id		= "hfsc",
1663	.init		= hfsc_init_qdisc,
1664	.change		= hfsc_change_qdisc,
1665	.reset		= hfsc_reset_qdisc,
1666	.destroy	= hfsc_destroy_qdisc,
1667	.dump		= hfsc_dump_qdisc,
1668	.enqueue	= hfsc_enqueue,
1669	.dequeue	= hfsc_dequeue,
1670	.peek		= qdisc_peek_dequeued,
1671	.cl_ops		= &hfsc_class_ops,
1672	.priv_size	= sizeof(struct hfsc_sched),
1673	.owner		= THIS_MODULE
1674};
1675
1676static int __init
1677hfsc_init(void)
1678{
1679	return register_qdisc(&hfsc_qdisc_ops);
1680}
1681
1682static void __exit
1683hfsc_cleanup(void)
1684{
1685	unregister_qdisc(&hfsc_qdisc_ops);
1686}
1687
1688MODULE_LICENSE("GPL");
1689module_init(hfsc_init);
1690module_exit(hfsc_cleanup);