linux/net/sched/sch_hfsc.c
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   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        unsigned int    refcnt;         /* usage count */
 114
 115        struct gnet_stats_basic_packed bstats;
 116        struct gnet_stats_queue qstats;
 117        struct gnet_stats_rate_est rate_est;
 118        unsigned int    level;          /* class level in hierarchy */
 119        struct tcf_proto *filter_list;  /* filter list */
 120        unsigned int    filter_cnt;     /* filter count */
 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        struct list_head dlist;         /* drop list member */
 134
 135        u64     cl_total;               /* total work in bytes */
 136        u64     cl_cumul;               /* cumulative work in bytes done by
 137                                           real-time criteria */
 138
 139        u64     cl_d;                   /* deadline*/
 140        u64     cl_e;                   /* eligible time */
 141        u64     cl_vt;                  /* virtual time */
 142        u64     cl_f;                   /* time when this class will fit for
 143                                           link-sharing, max(myf, cfmin) */
 144        u64     cl_myf;                 /* my fit-time (calculated from this
 145                                           class's own upperlimit curve) */
 146        u64     cl_myfadj;              /* my fit-time adjustment (to cancel
 147                                           history dependence) */
 148        u64     cl_cfmin;               /* earliest children's fit-time (used
 149                                           with cl_myf to obtain cl_f) */
 150        u64     cl_cvtmin;              /* minimal virtual time among the
 151                                           children fit for link-sharing
 152                                           (monotonic within a period) */
 153        u64     cl_vtadj;               /* intra-period cumulative vt
 154                                           adjustment */
 155        u64     cl_vtoff;               /* inter-period cumulative vt offset */
 156        u64     cl_cvtmax;              /* max child's vt in the last period */
 157        u64     cl_cvtoff;              /* cumulative cvtmax of all periods */
 158        u64     cl_pcvtoff;             /* parent's cvtoff at initialization
 159                                           time */
 160
 161        struct internal_sc cl_rsc;      /* internal real-time service curve */
 162        struct internal_sc cl_fsc;      /* internal fair service curve */
 163        struct internal_sc cl_usc;      /* internal upperlimit service curve */
 164        struct runtime_sc cl_deadline;  /* deadline curve */
 165        struct runtime_sc cl_eligible;  /* eligible curve */
 166        struct runtime_sc cl_virtual;   /* virtual curve */
 167        struct runtime_sc cl_ulimit;    /* upperlimit curve */
 168
 169        unsigned long   cl_flags;       /* which curves are valid */
 170        unsigned long   cl_vtperiod;    /* vt period sequence number */
 171        unsigned long   cl_parentperiod;/* parent's vt period sequence number*/
 172        unsigned long   cl_nactive;     /* number of active children */
 173};
 174
 175struct hfsc_sched {
 176        u16     defcls;                         /* default class id */
 177        struct hfsc_class root;                 /* root class */
 178        struct Qdisc_class_hash clhash;         /* class hash */
 179        struct rb_root eligible;                /* eligible tree */
 180        struct list_head droplist;              /* active leaf class list (for
 181                                                   dropping) */
 182        struct qdisc_watchdog watchdog;         /* watchdog timer */
 183};
 184
 185#define HT_INFINITY     0xffffffffffffffffULL   /* infinite time value */
 186
 187
 188/*
 189 * eligible tree holds backlogged classes being sorted by their eligible times.
 190 * there is one eligible tree per hfsc instance.
 191 */
 192
 193static void
 194eltree_insert(struct hfsc_class *cl)
 195{
 196        struct rb_node **p = &cl->sched->eligible.rb_node;
 197        struct rb_node *parent = NULL;
 198        struct hfsc_class *cl1;
 199
 200        while (*p != NULL) {
 201                parent = *p;
 202                cl1 = rb_entry(parent, struct hfsc_class, el_node);
 203                if (cl->cl_e >= cl1->cl_e)
 204                        p = &parent->rb_right;
 205                else
 206                        p = &parent->rb_left;
 207        }
 208        rb_link_node(&cl->el_node, parent, p);
 209        rb_insert_color(&cl->el_node, &cl->sched->eligible);
 210}
 211
 212static inline void
 213eltree_remove(struct hfsc_class *cl)
 214{
 215        rb_erase(&cl->el_node, &cl->sched->eligible);
 216}
 217
 218static inline void
 219eltree_update(struct hfsc_class *cl)
 220{
 221        eltree_remove(cl);
 222        eltree_insert(cl);
 223}
 224
 225/* find the class with the minimum deadline among the eligible classes */
 226static inline struct hfsc_class *
 227eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
 228{
 229        struct hfsc_class *p, *cl = NULL;
 230        struct rb_node *n;
 231
 232        for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
 233                p = rb_entry(n, struct hfsc_class, el_node);
 234                if (p->cl_e > cur_time)
 235                        break;
 236                if (cl == NULL || p->cl_d < cl->cl_d)
 237                        cl = p;
 238        }
 239        return cl;
 240}
 241
 242/* find the class with minimum eligible time among the eligible classes */
 243static inline struct hfsc_class *
 244eltree_get_minel(struct hfsc_sched *q)
 245{
 246        struct rb_node *n;
 247
 248        n = rb_first(&q->eligible);
 249        if (n == NULL)
 250                return NULL;
 251        return rb_entry(n, struct hfsc_class, el_node);
 252}
 253
 254/*
 255 * vttree holds holds backlogged child classes being sorted by their virtual
 256 * time. each intermediate class has one vttree.
 257 */
 258static void
 259vttree_insert(struct hfsc_class *cl)
 260{
 261        struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
 262        struct rb_node *parent = NULL;
 263        struct hfsc_class *cl1;
 264
 265        while (*p != NULL) {
 266                parent = *p;
 267                cl1 = rb_entry(parent, struct hfsc_class, vt_node);
 268                if (cl->cl_vt >= cl1->cl_vt)
 269                        p = &parent->rb_right;
 270                else
 271                        p = &parent->rb_left;
 272        }
 273        rb_link_node(&cl->vt_node, parent, p);
 274        rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
 275}
 276
 277static inline void
 278vttree_remove(struct hfsc_class *cl)
 279{
 280        rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
 281}
 282
 283static inline void
 284vttree_update(struct hfsc_class *cl)
 285{
 286        vttree_remove(cl);
 287        vttree_insert(cl);
 288}
 289
 290static inline struct hfsc_class *
 291vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
 292{
 293        struct hfsc_class *p;
 294        struct rb_node *n;
 295
 296        for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
 297                p = rb_entry(n, struct hfsc_class, vt_node);
 298                if (p->cl_f <= cur_time)
 299                        return p;
 300        }
 301        return NULL;
 302}
 303
 304/*
 305 * get the leaf class with the minimum vt in the hierarchy
 306 */
 307static struct hfsc_class *
 308vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
 309{
 310        /* if root-class's cfmin is bigger than cur_time nothing to do */
 311        if (cl->cl_cfmin > cur_time)
 312                return NULL;
 313
 314        while (cl->level > 0) {
 315                cl = vttree_firstfit(cl, cur_time);
 316                if (cl == NULL)
 317                        return NULL;
 318                /*
 319                 * update parent's cl_cvtmin.
 320                 */
 321                if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
 322                        cl->cl_parent->cl_cvtmin = cl->cl_vt;
 323        }
 324        return cl;
 325}
 326
 327static void
 328cftree_insert(struct hfsc_class *cl)
 329{
 330        struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
 331        struct rb_node *parent = NULL;
 332        struct hfsc_class *cl1;
 333
 334        while (*p != NULL) {
 335                parent = *p;
 336                cl1 = rb_entry(parent, struct hfsc_class, cf_node);
 337                if (cl->cl_f >= cl1->cl_f)
 338                        p = &parent->rb_right;
 339                else
 340                        p = &parent->rb_left;
 341        }
 342        rb_link_node(&cl->cf_node, parent, p);
 343        rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
 344}
 345
 346static inline void
 347cftree_remove(struct hfsc_class *cl)
 348{
 349        rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
 350}
 351
 352static inline void
 353cftree_update(struct hfsc_class *cl)
 354{
 355        cftree_remove(cl);
 356        cftree_insert(cl);
 357}
 358
 359/*
 360 * service curve support functions
 361 *
 362 *  external service curve parameters
 363 *      m: bps
 364 *      d: us
 365 *  internal service curve parameters
 366 *      sm: (bytes/psched_us) << SM_SHIFT
 367 *      ism: (psched_us/byte) << ISM_SHIFT
 368 *      dx: psched_us
 369 *
 370 * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
 371 *
 372 * sm and ism are scaled in order to keep effective digits.
 373 * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
 374 * digits in decimal using the following table.
 375 *
 376 *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
 377 *  ------------+-------------------------------------------------------
 378 *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
 379 *
 380 *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
 381 *
 382 * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
 383 */
 384#define SM_SHIFT        (30 - PSCHED_SHIFT)
 385#define ISM_SHIFT       (8 + PSCHED_SHIFT)
 386
 387#define SM_MASK         ((1ULL << SM_SHIFT) - 1)
 388#define ISM_MASK        ((1ULL << ISM_SHIFT) - 1)
 389
 390static inline u64
 391seg_x2y(u64 x, u64 sm)
 392{
 393        u64 y;
 394
 395        /*
 396         * compute
 397         *      y = x * sm >> SM_SHIFT
 398         * but divide it for the upper and lower bits to avoid overflow
 399         */
 400        y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
 401        return y;
 402}
 403
 404static inline u64
 405seg_y2x(u64 y, u64 ism)
 406{
 407        u64 x;
 408
 409        if (y == 0)
 410                x = 0;
 411        else if (ism == HT_INFINITY)
 412                x = HT_INFINITY;
 413        else {
 414                x = (y >> ISM_SHIFT) * ism
 415                    + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
 416        }
 417        return x;
 418}
 419
 420/* Convert m (bps) into sm (bytes/psched us) */
 421static u64
 422m2sm(u32 m)
 423{
 424        u64 sm;
 425
 426        sm = ((u64)m << SM_SHIFT);
 427        sm += PSCHED_TICKS_PER_SEC - 1;
 428        do_div(sm, PSCHED_TICKS_PER_SEC);
 429        return sm;
 430}
 431
 432/* convert m (bps) into ism (psched us/byte) */
 433static u64
 434m2ism(u32 m)
 435{
 436        u64 ism;
 437
 438        if (m == 0)
 439                ism = HT_INFINITY;
 440        else {
 441                ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
 442                ism += m - 1;
 443                do_div(ism, m);
 444        }
 445        return ism;
 446}
 447
 448/* convert d (us) into dx (psched us) */
 449static u64
 450d2dx(u32 d)
 451{
 452        u64 dx;
 453
 454        dx = ((u64)d * PSCHED_TICKS_PER_SEC);
 455        dx += USEC_PER_SEC - 1;
 456        do_div(dx, USEC_PER_SEC);
 457        return dx;
 458}
 459
 460/* convert sm (bytes/psched us) into m (bps) */
 461static u32
 462sm2m(u64 sm)
 463{
 464        u64 m;
 465
 466        m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
 467        return (u32)m;
 468}
 469
 470/* convert dx (psched us) into d (us) */
 471static u32
 472dx2d(u64 dx)
 473{
 474        u64 d;
 475
 476        d = dx * USEC_PER_SEC;
 477        do_div(d, PSCHED_TICKS_PER_SEC);
 478        return (u32)d;
 479}
 480
 481static void
 482sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
 483{
 484        isc->sm1  = m2sm(sc->m1);
 485        isc->ism1 = m2ism(sc->m1);
 486        isc->dx   = d2dx(sc->d);
 487        isc->dy   = seg_x2y(isc->dx, isc->sm1);
 488        isc->sm2  = m2sm(sc->m2);
 489        isc->ism2 = m2ism(sc->m2);
 490}
 491
 492/*
 493 * initialize the runtime service curve with the given internal
 494 * service curve starting at (x, y).
 495 */
 496static void
 497rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 498{
 499        rtsc->x    = x;
 500        rtsc->y    = y;
 501        rtsc->sm1  = isc->sm1;
 502        rtsc->ism1 = isc->ism1;
 503        rtsc->dx   = isc->dx;
 504        rtsc->dy   = isc->dy;
 505        rtsc->sm2  = isc->sm2;
 506        rtsc->ism2 = isc->ism2;
 507}
 508
 509/*
 510 * calculate the y-projection of the runtime service curve by the
 511 * given x-projection value
 512 */
 513static u64
 514rtsc_y2x(struct runtime_sc *rtsc, u64 y)
 515{
 516        u64 x;
 517
 518        if (y < rtsc->y)
 519                x = rtsc->x;
 520        else if (y <= rtsc->y + rtsc->dy) {
 521                /* x belongs to the 1st segment */
 522                if (rtsc->dy == 0)
 523                        x = rtsc->x + rtsc->dx;
 524                else
 525                        x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
 526        } else {
 527                /* x belongs to the 2nd segment */
 528                x = rtsc->x + rtsc->dx
 529                    + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
 530        }
 531        return x;
 532}
 533
 534static u64
 535rtsc_x2y(struct runtime_sc *rtsc, u64 x)
 536{
 537        u64 y;
 538
 539        if (x <= rtsc->x)
 540                y = rtsc->y;
 541        else if (x <= rtsc->x + rtsc->dx)
 542                /* y belongs to the 1st segment */
 543                y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
 544        else
 545                /* y belongs to the 2nd segment */
 546                y = rtsc->y + rtsc->dy
 547                    + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
 548        return y;
 549}
 550
 551/*
 552 * update the runtime service curve by taking the minimum of the current
 553 * runtime service curve and the service curve starting at (x, y).
 554 */
 555static void
 556rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 557{
 558        u64 y1, y2, dx, dy;
 559        u32 dsm;
 560
 561        if (isc->sm1 <= isc->sm2) {
 562                /* service curve is convex */
 563                y1 = rtsc_x2y(rtsc, x);
 564                if (y1 < y)
 565                        /* the current rtsc is smaller */
 566                        return;
 567                rtsc->x = x;
 568                rtsc->y = y;
 569                return;
 570        }
 571
 572        /*
 573         * service curve is concave
 574         * compute the two y values of the current rtsc
 575         *      y1: at x
 576         *      y2: at (x + dx)
 577         */
 578        y1 = rtsc_x2y(rtsc, x);
 579        if (y1 <= y) {
 580                /* rtsc is below isc, no change to rtsc */
 581                return;
 582        }
 583
 584        y2 = rtsc_x2y(rtsc, x + isc->dx);
 585        if (y2 >= y + isc->dy) {
 586                /* rtsc is above isc, replace rtsc by isc */
 587                rtsc->x = x;
 588                rtsc->y = y;
 589                rtsc->dx = isc->dx;
 590                rtsc->dy = isc->dy;
 591                return;
 592        }
 593
 594        /*
 595         * the two curves intersect
 596         * compute the offsets (dx, dy) using the reverse
 597         * function of seg_x2y()
 598         *      seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
 599         */
 600        dx = (y1 - y) << SM_SHIFT;
 601        dsm = isc->sm1 - isc->sm2;
 602        do_div(dx, dsm);
 603        /*
 604         * check if (x, y1) belongs to the 1st segment of rtsc.
 605         * if so, add the offset.
 606         */
 607        if (rtsc->x + rtsc->dx > x)
 608                dx += rtsc->x + rtsc->dx - x;
 609        dy = seg_x2y(dx, isc->sm1);
 610
 611        rtsc->x = x;
 612        rtsc->y = y;
 613        rtsc->dx = dx;
 614        rtsc->dy = dy;
 615}
 616
 617static void
 618init_ed(struct hfsc_class *cl, unsigned int next_len)
 619{
 620        u64 cur_time = psched_get_time();
 621
 622        /* update the deadline curve */
 623        rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
 624
 625        /*
 626         * update the eligible curve.
 627         * for concave, it is equal to the deadline curve.
 628         * for convex, it is a linear curve with slope m2.
 629         */
 630        cl->cl_eligible = cl->cl_deadline;
 631        if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
 632                cl->cl_eligible.dx = 0;
 633                cl->cl_eligible.dy = 0;
 634        }
 635
 636        /* compute e and d */
 637        cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
 638        cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 639
 640        eltree_insert(cl);
 641}
 642
 643static void
 644update_ed(struct hfsc_class *cl, unsigned int next_len)
 645{
 646        cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
 647        cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 648
 649        eltree_update(cl);
 650}
 651
 652static inline void
 653update_d(struct hfsc_class *cl, unsigned int next_len)
 654{
 655        cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 656}
 657
 658static inline void
 659update_cfmin(struct hfsc_class *cl)
 660{
 661        struct rb_node *n = rb_first(&cl->cf_tree);
 662        struct hfsc_class *p;
 663
 664        if (n == NULL) {
 665                cl->cl_cfmin = 0;
 666                return;
 667        }
 668        p = rb_entry(n, struct hfsc_class, cf_node);
 669        cl->cl_cfmin = p->cl_f;
 670}
 671
 672static void
 673init_vf(struct hfsc_class *cl, unsigned int len)
 674{
 675        struct hfsc_class *max_cl;
 676        struct rb_node *n;
 677        u64 vt, f, cur_time;
 678        int go_active;
 679
 680        cur_time = 0;
 681        go_active = 1;
 682        for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
 683                if (go_active && cl->cl_nactive++ == 0)
 684                        go_active = 1;
 685                else
 686                        go_active = 0;
 687
 688                if (go_active) {
 689                        n = rb_last(&cl->cl_parent->vt_tree);
 690                        if (n != NULL) {
 691                                max_cl = rb_entry(n, struct hfsc_class, vt_node);
 692                                /*
 693                                 * set vt to the average of the min and max
 694                                 * classes.  if the parent's period didn't
 695                                 * change, don't decrease vt of the class.
 696                                 */
 697                                vt = max_cl->cl_vt;
 698                                if (cl->cl_parent->cl_cvtmin != 0)
 699                                        vt = (cl->cl_parent->cl_cvtmin + vt)/2;
 700
 701                                if (cl->cl_parent->cl_vtperiod !=
 702                                    cl->cl_parentperiod || vt > cl->cl_vt)
 703                                        cl->cl_vt = vt;
 704                        } else {
 705                                /*
 706                                 * first child for a new parent backlog period.
 707                                 * add parent's cvtmax to cvtoff to make a new
 708                                 * vt (vtoff + vt) larger than the vt in the
 709                                 * last period for all children.
 710                                 */
 711                                vt = cl->cl_parent->cl_cvtmax;
 712                                cl->cl_parent->cl_cvtoff += vt;
 713                                cl->cl_parent->cl_cvtmax = 0;
 714                                cl->cl_parent->cl_cvtmin = 0;
 715                                cl->cl_vt = 0;
 716                        }
 717
 718                        cl->cl_vtoff = cl->cl_parent->cl_cvtoff -
 719                                                        cl->cl_pcvtoff;
 720
 721                        /* update the virtual curve */
 722                        vt = cl->cl_vt + cl->cl_vtoff;
 723                        rtsc_min(&cl->cl_virtual, &cl->cl_fsc, vt,
 724                                                      cl->cl_total);
 725                        if (cl->cl_virtual.x == vt) {
 726                                cl->cl_virtual.x -= cl->cl_vtoff;
 727                                cl->cl_vtoff = 0;
 728                        }
 729                        cl->cl_vtadj = 0;
 730
 731                        cl->cl_vtperiod++;  /* increment vt period */
 732                        cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
 733                        if (cl->cl_parent->cl_nactive == 0)
 734                                cl->cl_parentperiod++;
 735                        cl->cl_f = 0;
 736
 737                        vttree_insert(cl);
 738                        cftree_insert(cl);
 739
 740                        if (cl->cl_flags & HFSC_USC) {
 741                                /* class has upper limit curve */
 742                                if (cur_time == 0)
 743                                        cur_time = psched_get_time();
 744
 745                                /* update the ulimit curve */
 746                                rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
 747                                         cl->cl_total);
 748                                /* compute myf */
 749                                cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
 750                                                      cl->cl_total);
 751                                cl->cl_myfadj = 0;
 752                        }
 753                }
 754
 755                f = max(cl->cl_myf, cl->cl_cfmin);
 756                if (f != cl->cl_f) {
 757                        cl->cl_f = f;
 758                        cftree_update(cl);
 759                }
 760                update_cfmin(cl->cl_parent);
 761        }
 762}
 763
 764static void
 765update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
 766{
 767        u64 f; /* , myf_bound, delta; */
 768        int go_passive = 0;
 769
 770        if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
 771                go_passive = 1;
 772
 773        for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
 774                cl->cl_total += len;
 775
 776                if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
 777                        continue;
 778
 779                if (go_passive && --cl->cl_nactive == 0)
 780                        go_passive = 1;
 781                else
 782                        go_passive = 0;
 783
 784                if (go_passive) {
 785                        /* no more active child, going passive */
 786
 787                        /* update cvtmax of the parent class */
 788                        if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
 789                                cl->cl_parent->cl_cvtmax = cl->cl_vt;
 790
 791                        /* remove this class from the vt tree */
 792                        vttree_remove(cl);
 793
 794                        cftree_remove(cl);
 795                        update_cfmin(cl->cl_parent);
 796
 797                        continue;
 798                }
 799
 800                /*
 801                 * update vt and f
 802                 */
 803                cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
 804                            - cl->cl_vtoff + cl->cl_vtadj;
 805
 806                /*
 807                 * if vt of the class is smaller than cvtmin,
 808                 * the class was skipped in the past due to non-fit.
 809                 * if so, we need to adjust vtadj.
 810                 */
 811                if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
 812                        cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
 813                        cl->cl_vt = cl->cl_parent->cl_cvtmin;
 814                }
 815
 816                /* update the vt tree */
 817                vttree_update(cl);
 818
 819                if (cl->cl_flags & HFSC_USC) {
 820                        cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
 821                                                              cl->cl_total);
 822#if 0
 823                        /*
 824                         * This code causes classes to stay way under their
 825                         * limit when multiple classes are used at gigabit
 826                         * speed. needs investigation. -kaber
 827                         */
 828                        /*
 829                         * if myf lags behind by more than one clock tick
 830                         * from the current time, adjust myfadj to prevent
 831                         * a rate-limited class from going greedy.
 832                         * in a steady state under rate-limiting, myf
 833                         * fluctuates within one clock tick.
 834                         */
 835                        myf_bound = cur_time - PSCHED_JIFFIE2US(1);
 836                        if (cl->cl_myf < myf_bound) {
 837                                delta = cur_time - cl->cl_myf;
 838                                cl->cl_myfadj += delta;
 839                                cl->cl_myf += delta;
 840                        }
 841#endif
 842                }
 843
 844                f = max(cl->cl_myf, cl->cl_cfmin);
 845                if (f != cl->cl_f) {
 846                        cl->cl_f = f;
 847                        cftree_update(cl);
 848                        update_cfmin(cl->cl_parent);
 849                }
 850        }
 851}
 852
 853static void
 854set_active(struct hfsc_class *cl, unsigned int len)
 855{
 856        if (cl->cl_flags & HFSC_RSC)
 857                init_ed(cl, len);
 858        if (cl->cl_flags & HFSC_FSC)
 859                init_vf(cl, len);
 860
 861        list_add_tail(&cl->dlist, &cl->sched->droplist);
 862}
 863
 864static void
 865set_passive(struct hfsc_class *cl)
 866{
 867        if (cl->cl_flags & HFSC_RSC)
 868                eltree_remove(cl);
 869
 870        list_del(&cl->dlist);
 871
 872        /*
 873         * vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
 874         * needs to be called explicitly to remove a class from vttree.
 875         */
 876}
 877
 878static unsigned int
 879qdisc_peek_len(struct Qdisc *sch)
 880{
 881        struct sk_buff *skb;
 882        unsigned int len;
 883
 884        skb = sch->ops->peek(sch);
 885        if (skb == NULL) {
 886                qdisc_warn_nonwc("qdisc_peek_len", sch);
 887                return 0;
 888        }
 889        len = qdisc_pkt_len(skb);
 890
 891        return len;
 892}
 893
 894static void
 895hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
 896{
 897        unsigned int len = cl->qdisc->q.qlen;
 898
 899        qdisc_reset(cl->qdisc);
 900        qdisc_tree_decrease_qlen(cl->qdisc, len);
 901}
 902
 903static void
 904hfsc_adjust_levels(struct hfsc_class *cl)
 905{
 906        struct hfsc_class *p;
 907        unsigned int level;
 908
 909        do {
 910                level = 0;
 911                list_for_each_entry(p, &cl->children, siblings) {
 912                        if (p->level >= level)
 913                                level = p->level + 1;
 914                }
 915                cl->level = level;
 916        } while ((cl = cl->cl_parent) != NULL);
 917}
 918
 919static inline struct hfsc_class *
 920hfsc_find_class(u32 classid, struct Qdisc *sch)
 921{
 922        struct hfsc_sched *q = qdisc_priv(sch);
 923        struct Qdisc_class_common *clc;
 924
 925        clc = qdisc_class_find(&q->clhash, classid);
 926        if (clc == NULL)
 927                return NULL;
 928        return container_of(clc, struct hfsc_class, cl_common);
 929}
 930
 931static void
 932hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
 933                u64 cur_time)
 934{
 935        sc2isc(rsc, &cl->cl_rsc);
 936        rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
 937        cl->cl_eligible = cl->cl_deadline;
 938        if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
 939                cl->cl_eligible.dx = 0;
 940                cl->cl_eligible.dy = 0;
 941        }
 942        cl->cl_flags |= HFSC_RSC;
 943}
 944
 945static void
 946hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
 947{
 948        sc2isc(fsc, &cl->cl_fsc);
 949        rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
 950        cl->cl_flags |= HFSC_FSC;
 951}
 952
 953static void
 954hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
 955                u64 cur_time)
 956{
 957        sc2isc(usc, &cl->cl_usc);
 958        rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
 959        cl->cl_flags |= HFSC_USC;
 960}
 961
 962static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
 963        [TCA_HFSC_RSC]  = { .len = sizeof(struct tc_service_curve) },
 964        [TCA_HFSC_FSC]  = { .len = sizeof(struct tc_service_curve) },
 965        [TCA_HFSC_USC]  = { .len = sizeof(struct tc_service_curve) },
 966};
 967
 968static int
 969hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 970                  struct nlattr **tca, unsigned long *arg)
 971{
 972        struct hfsc_sched *q = qdisc_priv(sch);
 973        struct hfsc_class *cl = (struct hfsc_class *)*arg;
 974        struct hfsc_class *parent = NULL;
 975        struct nlattr *opt = tca[TCA_OPTIONS];
 976        struct nlattr *tb[TCA_HFSC_MAX + 1];
 977        struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
 978        u64 cur_time;
 979        int err;
 980
 981        if (opt == NULL)
 982                return -EINVAL;
 983
 984        err = nla_parse_nested(tb, TCA_HFSC_MAX, opt, hfsc_policy);
 985        if (err < 0)
 986                return err;
 987
 988        if (tb[TCA_HFSC_RSC]) {
 989                rsc = nla_data(tb[TCA_HFSC_RSC]);
 990                if (rsc->m1 == 0 && rsc->m2 == 0)
 991                        rsc = NULL;
 992        }
 993
 994        if (tb[TCA_HFSC_FSC]) {
 995                fsc = nla_data(tb[TCA_HFSC_FSC]);
 996                if (fsc->m1 == 0 && fsc->m2 == 0)
 997                        fsc = NULL;
 998        }
 999
1000        if (tb[TCA_HFSC_USC]) {
1001                usc = nla_data(tb[TCA_HFSC_USC]);
1002                if (usc->m1 == 0 && usc->m2 == 0)
1003                        usc = NULL;
1004        }
1005
1006        if (cl != NULL) {
1007                if (parentid) {
1008                        if (cl->cl_parent &&
1009                            cl->cl_parent->cl_common.classid != parentid)
1010                                return -EINVAL;
1011                        if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
1012                                return -EINVAL;
1013                }
1014                cur_time = psched_get_time();
1015
1016                if (tca[TCA_RATE]) {
1017                        err = gen_replace_estimator(&cl->bstats, &cl->rate_est,
1018                                              qdisc_root_sleeping_lock(sch),
1019                                              tca[TCA_RATE]);
1020                        if (err)
1021                                return err;
1022                }
1023
1024                sch_tree_lock(sch);
1025                if (rsc != NULL)
1026                        hfsc_change_rsc(cl, rsc, cur_time);
1027                if (fsc != NULL)
1028                        hfsc_change_fsc(cl, fsc);
1029                if (usc != NULL)
1030                        hfsc_change_usc(cl, usc, cur_time);
1031
1032                if (cl->qdisc->q.qlen != 0) {
1033                        if (cl->cl_flags & HFSC_RSC)
1034                                update_ed(cl, qdisc_peek_len(cl->qdisc));
1035                        if (cl->cl_flags & HFSC_FSC)
1036                                update_vf(cl, 0, cur_time);
1037                }
1038                sch_tree_unlock(sch);
1039
1040                return 0;
1041        }
1042
1043        if (parentid == TC_H_ROOT)
1044                return -EEXIST;
1045
1046        parent = &q->root;
1047        if (parentid) {
1048                parent = hfsc_find_class(parentid, sch);
1049                if (parent == NULL)
1050                        return -ENOENT;
1051        }
1052
1053        if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1054                return -EINVAL;
1055        if (hfsc_find_class(classid, sch))
1056                return -EEXIST;
1057
1058        if (rsc == NULL && fsc == NULL)
1059                return -EINVAL;
1060
1061        cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1062        if (cl == NULL)
1063                return -ENOBUFS;
1064
1065        if (tca[TCA_RATE]) {
1066                err = gen_new_estimator(&cl->bstats, &cl->rate_est,
1067                                        qdisc_root_sleeping_lock(sch),
1068                                        tca[TCA_RATE]);
1069                if (err) {
1070                        kfree(cl);
1071                        return err;
1072                }
1073        }
1074
1075        if (rsc != NULL)
1076                hfsc_change_rsc(cl, rsc, 0);
1077        if (fsc != NULL)
1078                hfsc_change_fsc(cl, fsc);
1079        if (usc != NULL)
1080                hfsc_change_usc(cl, usc, 0);
1081
1082        cl->cl_common.classid = classid;
1083        cl->refcnt    = 1;
1084        cl->sched     = q;
1085        cl->cl_parent = parent;
1086        cl->qdisc = qdisc_create_dflt(sch->dev_queue,
1087                                      &pfifo_qdisc_ops, classid);
1088        if (cl->qdisc == NULL)
1089                cl->qdisc = &noop_qdisc;
1090        INIT_LIST_HEAD(&cl->children);
1091        cl->vt_tree = RB_ROOT;
1092        cl->cf_tree = RB_ROOT;
1093
1094        sch_tree_lock(sch);
1095        qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1096        list_add_tail(&cl->siblings, &parent->children);
1097        if (parent->level == 0)
1098                hfsc_purge_queue(sch, parent);
1099        hfsc_adjust_levels(parent);
1100        cl->cl_pcvtoff = parent->cl_cvtoff;
1101        sch_tree_unlock(sch);
1102
1103        qdisc_class_hash_grow(sch, &q->clhash);
1104
1105        *arg = (unsigned long)cl;
1106        return 0;
1107}
1108
1109static void
1110hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1111{
1112        struct hfsc_sched *q = qdisc_priv(sch);
1113
1114        tcf_destroy_chain(&cl->filter_list);
1115        qdisc_destroy(cl->qdisc);
1116        gen_kill_estimator(&cl->bstats, &cl->rate_est);
1117        if (cl != &q->root)
1118                kfree(cl);
1119}
1120
1121static int
1122hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1123{
1124        struct hfsc_sched *q = qdisc_priv(sch);
1125        struct hfsc_class *cl = (struct hfsc_class *)arg;
1126
1127        if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1128                return -EBUSY;
1129
1130        sch_tree_lock(sch);
1131
1132        list_del(&cl->siblings);
1133        hfsc_adjust_levels(cl->cl_parent);
1134
1135        hfsc_purge_queue(sch, cl);
1136        qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1137
1138        BUG_ON(--cl->refcnt == 0);
1139        /*
1140         * This shouldn't happen: we "hold" one cops->get() when called
1141         * from tc_ctl_tclass; the destroy method is done from cops->put().
1142         */
1143
1144        sch_tree_unlock(sch);
1145        return 0;
1146}
1147
1148static struct hfsc_class *
1149hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1150{
1151        struct hfsc_sched *q = qdisc_priv(sch);
1152        struct hfsc_class *head, *cl;
1153        struct tcf_result res;
1154        struct tcf_proto *tcf;
1155        int result;
1156
1157        if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1158            (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1159                if (cl->level == 0)
1160                        return cl;
1161
1162        *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1163        head = &q->root;
1164        tcf = q->root.filter_list;
1165        while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
1166#ifdef CONFIG_NET_CLS_ACT
1167                switch (result) {
1168                case TC_ACT_QUEUED:
1169                case TC_ACT_STOLEN:
1170                        *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1171                case TC_ACT_SHOT:
1172                        return NULL;
1173                }
1174#endif
1175                cl = (struct hfsc_class *)res.class;
1176                if (!cl) {
1177                        cl = hfsc_find_class(res.classid, sch);
1178                        if (!cl)
1179                                break; /* filter selected invalid classid */
1180                        if (cl->level >= head->level)
1181                                break; /* filter may only point downwards */
1182                }
1183
1184                if (cl->level == 0)
1185                        return cl; /* hit leaf class */
1186
1187                /* apply inner filter chain */
1188                tcf = cl->filter_list;
1189                head = cl;
1190        }
1191
1192        /* classification failed, try default class */
1193        cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1194        if (cl == NULL || cl->level > 0)
1195                return NULL;
1196
1197        return cl;
1198}
1199
1200static int
1201hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1202                 struct Qdisc **old)
1203{
1204        struct hfsc_class *cl = (struct hfsc_class *)arg;
1205
1206        if (cl->level > 0)
1207                return -EINVAL;
1208        if (new == NULL) {
1209                new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1210                                        cl->cl_common.classid);
1211                if (new == NULL)
1212                        new = &noop_qdisc;
1213        }
1214
1215        sch_tree_lock(sch);
1216        hfsc_purge_queue(sch, cl);
1217        *old = cl->qdisc;
1218        cl->qdisc = new;
1219        sch_tree_unlock(sch);
1220        return 0;
1221}
1222
1223static struct Qdisc *
1224hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1225{
1226        struct hfsc_class *cl = (struct hfsc_class *)arg;
1227
1228        if (cl->level == 0)
1229                return cl->qdisc;
1230
1231        return NULL;
1232}
1233
1234static void
1235hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1236{
1237        struct hfsc_class *cl = (struct hfsc_class *)arg;
1238
1239        if (cl->qdisc->q.qlen == 0) {
1240                update_vf(cl, 0, 0);
1241                set_passive(cl);
1242        }
1243}
1244
1245static unsigned long
1246hfsc_get_class(struct Qdisc *sch, u32 classid)
1247{
1248        struct hfsc_class *cl = hfsc_find_class(classid, sch);
1249
1250        if (cl != NULL)
1251                cl->refcnt++;
1252
1253        return (unsigned long)cl;
1254}
1255
1256static void
1257hfsc_put_class(struct Qdisc *sch, unsigned long arg)
1258{
1259        struct hfsc_class *cl = (struct hfsc_class *)arg;
1260
1261        if (--cl->refcnt == 0)
1262                hfsc_destroy_class(sch, cl);
1263}
1264
1265static unsigned long
1266hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1267{
1268        struct hfsc_class *p = (struct hfsc_class *)parent;
1269        struct hfsc_class *cl = hfsc_find_class(classid, sch);
1270
1271        if (cl != NULL) {
1272                if (p != NULL && p->level <= cl->level)
1273                        return 0;
1274                cl->filter_cnt++;
1275        }
1276
1277        return (unsigned long)cl;
1278}
1279
1280static void
1281hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1282{
1283        struct hfsc_class *cl = (struct hfsc_class *)arg;
1284
1285        cl->filter_cnt--;
1286}
1287
1288static struct tcf_proto **
1289hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg)
1290{
1291        struct hfsc_sched *q = qdisc_priv(sch);
1292        struct hfsc_class *cl = (struct hfsc_class *)arg;
1293
1294        if (cl == NULL)
1295                cl = &q->root;
1296
1297        return &cl->filter_list;
1298}
1299
1300static int
1301hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1302{
1303        struct tc_service_curve tsc;
1304
1305        tsc.m1 = sm2m(sc->sm1);
1306        tsc.d  = dx2d(sc->dx);
1307        tsc.m2 = sm2m(sc->sm2);
1308        if (nla_put(skb, attr, sizeof(tsc), &tsc))
1309                goto nla_put_failure;
1310
1311        return skb->len;
1312
1313 nla_put_failure:
1314        return -1;
1315}
1316
1317static int
1318hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1319{
1320        if ((cl->cl_flags & HFSC_RSC) &&
1321            (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1322                goto nla_put_failure;
1323
1324        if ((cl->cl_flags & HFSC_FSC) &&
1325            (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1326                goto nla_put_failure;
1327
1328        if ((cl->cl_flags & HFSC_USC) &&
1329            (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1330                goto nla_put_failure;
1331
1332        return skb->len;
1333
1334 nla_put_failure:
1335        return -1;
1336}
1337
1338static int
1339hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1340                struct tcmsg *tcm)
1341{
1342        struct hfsc_class *cl = (struct hfsc_class *)arg;
1343        struct nlattr *nest;
1344
1345        tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1346                                          TC_H_ROOT;
1347        tcm->tcm_handle = cl->cl_common.classid;
1348        if (cl->level == 0)
1349                tcm->tcm_info = cl->qdisc->handle;
1350
1351        nest = nla_nest_start(skb, TCA_OPTIONS);
1352        if (nest == NULL)
1353                goto nla_put_failure;
1354        if (hfsc_dump_curves(skb, cl) < 0)
1355                goto nla_put_failure;
1356        nla_nest_end(skb, nest);
1357        return skb->len;
1358
1359 nla_put_failure:
1360        nla_nest_cancel(skb, nest);
1361        return -EMSGSIZE;
1362}
1363
1364static int
1365hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1366        struct gnet_dump *d)
1367{
1368        struct hfsc_class *cl = (struct hfsc_class *)arg;
1369        struct tc_hfsc_stats xstats;
1370
1371        cl->qstats.qlen = cl->qdisc->q.qlen;
1372        cl->qstats.backlog = cl->qdisc->qstats.backlog;
1373        xstats.level   = cl->level;
1374        xstats.period  = cl->cl_vtperiod;
1375        xstats.work    = cl->cl_total;
1376        xstats.rtwork  = cl->cl_cumul;
1377
1378        if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
1379            gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 ||
1380            gnet_stats_copy_queue(d, &cl->qstats) < 0)
1381                return -1;
1382
1383        return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1384}
1385
1386
1387
1388static void
1389hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1390{
1391        struct hfsc_sched *q = qdisc_priv(sch);
1392        struct hlist_node *n;
1393        struct hfsc_class *cl;
1394        unsigned int i;
1395
1396        if (arg->stop)
1397                return;
1398
1399        for (i = 0; i < q->clhash.hashsize; i++) {
1400                hlist_for_each_entry(cl, n, &q->clhash.hash[i],
1401                                     cl_common.hnode) {
1402                        if (arg->count < arg->skip) {
1403                                arg->count++;
1404                                continue;
1405                        }
1406                        if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1407                                arg->stop = 1;
1408                                return;
1409                        }
1410                        arg->count++;
1411                }
1412        }
1413}
1414
1415static void
1416hfsc_schedule_watchdog(struct Qdisc *sch)
1417{
1418        struct hfsc_sched *q = qdisc_priv(sch);
1419        struct hfsc_class *cl;
1420        u64 next_time = 0;
1421
1422        cl = eltree_get_minel(q);
1423        if (cl)
1424                next_time = cl->cl_e;
1425        if (q->root.cl_cfmin != 0) {
1426                if (next_time == 0 || next_time > q->root.cl_cfmin)
1427                        next_time = q->root.cl_cfmin;
1428        }
1429        WARN_ON(next_time == 0);
1430        qdisc_watchdog_schedule(&q->watchdog, next_time);
1431}
1432
1433static int
1434hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt)
1435{
1436        struct hfsc_sched *q = qdisc_priv(sch);
1437        struct tc_hfsc_qopt *qopt;
1438        int err;
1439
1440        if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1441                return -EINVAL;
1442        qopt = nla_data(opt);
1443
1444        q->defcls = qopt->defcls;
1445        err = qdisc_class_hash_init(&q->clhash);
1446        if (err < 0)
1447                return err;
1448        q->eligible = RB_ROOT;
1449        INIT_LIST_HEAD(&q->droplist);
1450
1451        q->root.cl_common.classid = sch->handle;
1452        q->root.refcnt  = 1;
1453        q->root.sched   = q;
1454        q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1455                                          sch->handle);
1456        if (q->root.qdisc == NULL)
1457                q->root.qdisc = &noop_qdisc;
1458        INIT_LIST_HEAD(&q->root.children);
1459        q->root.vt_tree = RB_ROOT;
1460        q->root.cf_tree = RB_ROOT;
1461
1462        qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1463        qdisc_class_hash_grow(sch, &q->clhash);
1464
1465        qdisc_watchdog_init(&q->watchdog, sch);
1466
1467        return 0;
1468}
1469
1470static int
1471hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt)
1472{
1473        struct hfsc_sched *q = qdisc_priv(sch);
1474        struct tc_hfsc_qopt *qopt;
1475
1476        if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1477                return -EINVAL;
1478        qopt = nla_data(opt);
1479
1480        sch_tree_lock(sch);
1481        q->defcls = qopt->defcls;
1482        sch_tree_unlock(sch);
1483
1484        return 0;
1485}
1486
1487static void
1488hfsc_reset_class(struct hfsc_class *cl)
1489{
1490        cl->cl_total        = 0;
1491        cl->cl_cumul        = 0;
1492        cl->cl_d            = 0;
1493        cl->cl_e            = 0;
1494        cl->cl_vt           = 0;
1495        cl->cl_vtadj        = 0;
1496        cl->cl_vtoff        = 0;
1497        cl->cl_cvtmin       = 0;
1498        cl->cl_cvtmax       = 0;
1499        cl->cl_cvtoff       = 0;
1500        cl->cl_pcvtoff      = 0;
1501        cl->cl_vtperiod     = 0;
1502        cl->cl_parentperiod = 0;
1503        cl->cl_f            = 0;
1504        cl->cl_myf          = 0;
1505        cl->cl_myfadj       = 0;
1506        cl->cl_cfmin        = 0;
1507        cl->cl_nactive      = 0;
1508
1509        cl->vt_tree = RB_ROOT;
1510        cl->cf_tree = RB_ROOT;
1511        qdisc_reset(cl->qdisc);
1512
1513        if (cl->cl_flags & HFSC_RSC)
1514                rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1515        if (cl->cl_flags & HFSC_FSC)
1516                rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1517        if (cl->cl_flags & HFSC_USC)
1518                rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1519}
1520
1521static void
1522hfsc_reset_qdisc(struct Qdisc *sch)
1523{
1524        struct hfsc_sched *q = qdisc_priv(sch);
1525        struct hfsc_class *cl;
1526        struct hlist_node *n;
1527        unsigned int i;
1528
1529        for (i = 0; i < q->clhash.hashsize; i++) {
1530                hlist_for_each_entry(cl, n, &q->clhash.hash[i], cl_common.hnode)
1531                        hfsc_reset_class(cl);
1532        }
1533        q->eligible = RB_ROOT;
1534        INIT_LIST_HEAD(&q->droplist);
1535        qdisc_watchdog_cancel(&q->watchdog);
1536        sch->q.qlen = 0;
1537}
1538
1539static void
1540hfsc_destroy_qdisc(struct Qdisc *sch)
1541{
1542        struct hfsc_sched *q = qdisc_priv(sch);
1543        struct hlist_node *n, *next;
1544        struct hfsc_class *cl;
1545        unsigned int i;
1546
1547        for (i = 0; i < q->clhash.hashsize; i++) {
1548                hlist_for_each_entry(cl, n, &q->clhash.hash[i], cl_common.hnode)
1549                        tcf_destroy_chain(&cl->filter_list);
1550        }
1551        for (i = 0; i < q->clhash.hashsize; i++) {
1552                hlist_for_each_entry_safe(cl, n, next, &q->clhash.hash[i],
1553                                          cl_common.hnode)
1554                        hfsc_destroy_class(sch, cl);
1555        }
1556        qdisc_class_hash_destroy(&q->clhash);
1557        qdisc_watchdog_cancel(&q->watchdog);
1558}
1559
1560static int
1561hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1562{
1563        struct hfsc_sched *q = qdisc_priv(sch);
1564        unsigned char *b = skb_tail_pointer(skb);
1565        struct tc_hfsc_qopt qopt;
1566        struct hfsc_class *cl;
1567        struct hlist_node *n;
1568        unsigned int i;
1569
1570        sch->qstats.backlog = 0;
1571        for (i = 0; i < q->clhash.hashsize; i++) {
1572                hlist_for_each_entry(cl, n, &q->clhash.hash[i], cl_common.hnode)
1573                        sch->qstats.backlog += cl->qdisc->qstats.backlog;
1574        }
1575
1576        qopt.defcls = q->defcls;
1577        if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1578                goto nla_put_failure;
1579        return skb->len;
1580
1581 nla_put_failure:
1582        nlmsg_trim(skb, b);
1583        return -1;
1584}
1585
1586static int
1587hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
1588{
1589        struct hfsc_class *cl;
1590        int uninitialized_var(err);
1591
1592        cl = hfsc_classify(skb, sch, &err);
1593        if (cl == NULL) {
1594                if (err & __NET_XMIT_BYPASS)
1595                        sch->qstats.drops++;
1596                kfree_skb(skb);
1597                return err;
1598        }
1599
1600        err = qdisc_enqueue(skb, cl->qdisc);
1601        if (unlikely(err != NET_XMIT_SUCCESS)) {
1602                if (net_xmit_drop_count(err)) {
1603                        cl->qstats.drops++;
1604                        sch->qstats.drops++;
1605                }
1606                return err;
1607        }
1608
1609        if (cl->qdisc->q.qlen == 1)
1610                set_active(cl, qdisc_pkt_len(skb));
1611
1612        sch->q.qlen++;
1613
1614        return NET_XMIT_SUCCESS;
1615}
1616
1617static struct sk_buff *
1618hfsc_dequeue(struct Qdisc *sch)
1619{
1620        struct hfsc_sched *q = qdisc_priv(sch);
1621        struct hfsc_class *cl;
1622        struct sk_buff *skb;
1623        u64 cur_time;
1624        unsigned int next_len;
1625        int realtime = 0;
1626
1627        if (sch->q.qlen == 0)
1628                return NULL;
1629
1630        cur_time = psched_get_time();
1631
1632        /*
1633         * if there are eligible classes, use real-time criteria.
1634         * find the class with the minimum deadline among
1635         * the eligible classes.
1636         */
1637        cl = eltree_get_mindl(q, cur_time);
1638        if (cl) {
1639                realtime = 1;
1640        } else {
1641                /*
1642                 * use link-sharing criteria
1643                 * get the class with the minimum vt in the hierarchy
1644                 */
1645                cl = vttree_get_minvt(&q->root, cur_time);
1646                if (cl == NULL) {
1647                        sch->qstats.overlimits++;
1648                        hfsc_schedule_watchdog(sch);
1649                        return NULL;
1650                }
1651        }
1652
1653        skb = qdisc_dequeue_peeked(cl->qdisc);
1654        if (skb == NULL) {
1655                qdisc_warn_nonwc("HFSC", cl->qdisc);
1656                return NULL;
1657        }
1658
1659        bstats_update(&cl->bstats, skb);
1660        update_vf(cl, qdisc_pkt_len(skb), cur_time);
1661        if (realtime)
1662                cl->cl_cumul += qdisc_pkt_len(skb);
1663
1664        if (cl->qdisc->q.qlen != 0) {
1665                if (cl->cl_flags & HFSC_RSC) {
1666                        /* update ed */
1667                        next_len = qdisc_peek_len(cl->qdisc);
1668                        if (realtime)
1669                                update_ed(cl, next_len);
1670                        else
1671                                update_d(cl, next_len);
1672                }
1673        } else {
1674                /* the class becomes passive */
1675                set_passive(cl);
1676        }
1677
1678        qdisc_unthrottled(sch);
1679        qdisc_bstats_update(sch, skb);
1680        sch->q.qlen--;
1681
1682        return skb;
1683}
1684
1685static unsigned int
1686hfsc_drop(struct Qdisc *sch)
1687{
1688        struct hfsc_sched *q = qdisc_priv(sch);
1689        struct hfsc_class *cl;
1690        unsigned int len;
1691
1692        list_for_each_entry(cl, &q->droplist, dlist) {
1693                if (cl->qdisc->ops->drop != NULL &&
1694                    (len = cl->qdisc->ops->drop(cl->qdisc)) > 0) {
1695                        if (cl->qdisc->q.qlen == 0) {
1696                                update_vf(cl, 0, 0);
1697                                set_passive(cl);
1698                        } else {
1699                                list_move_tail(&cl->dlist, &q->droplist);
1700                        }
1701                        cl->qstats.drops++;
1702                        sch->qstats.drops++;
1703                        sch->q.qlen--;
1704                        return len;
1705                }
1706        }
1707        return 0;
1708}
1709
1710static const struct Qdisc_class_ops hfsc_class_ops = {
1711        .change         = hfsc_change_class,
1712        .delete         = hfsc_delete_class,
1713        .graft          = hfsc_graft_class,
1714        .leaf           = hfsc_class_leaf,
1715        .qlen_notify    = hfsc_qlen_notify,
1716        .get            = hfsc_get_class,
1717        .put            = hfsc_put_class,
1718        .bind_tcf       = hfsc_bind_tcf,
1719        .unbind_tcf     = hfsc_unbind_tcf,
1720        .tcf_chain      = hfsc_tcf_chain,
1721        .dump           = hfsc_dump_class,
1722        .dump_stats     = hfsc_dump_class_stats,
1723        .walk           = hfsc_walk
1724};
1725
1726static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1727        .id             = "hfsc",
1728        .init           = hfsc_init_qdisc,
1729        .change         = hfsc_change_qdisc,
1730        .reset          = hfsc_reset_qdisc,
1731        .destroy        = hfsc_destroy_qdisc,
1732        .dump           = hfsc_dump_qdisc,
1733        .enqueue        = hfsc_enqueue,
1734        .dequeue        = hfsc_dequeue,
1735        .peek           = qdisc_peek_dequeued,
1736        .drop           = hfsc_drop,
1737        .cl_ops         = &hfsc_class_ops,
1738        .priv_size      = sizeof(struct hfsc_sched),
1739        .owner          = THIS_MODULE
1740};
1741
1742static int __init
1743hfsc_init(void)
1744{
1745        return register_qdisc(&hfsc_qdisc_ops);
1746}
1747
1748static void __exit
1749hfsc_cleanup(void)
1750{
1751        unregister_qdisc(&hfsc_qdisc_ops);
1752}
1753
1754MODULE_LICENSE("GPL");
1755module_init(hfsc_init);
1756module_exit(hfsc_cleanup);
1757
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