net/sched/sch_hfsc.c

   1 /*
   2  * Copyright (c) 2003 Patrick McHardy, <kaber@trash.net>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * 2003-10-17 - Ported from altq
  10  */
  11 /*
  12  * Copyright (c) 1997-1999 Carnegie Mellon University. All Rights Reserved.
  13  *
  14  * Permission to use, copy, modify, and distribute this software and
  15  * its documentation is hereby granted (including for commercial or
  16  * for-profit use), provided that both the copyright notice and this
  17  * permission notice appear in all copies of the software, derivative
  18  * works, or modified versions, and any portions thereof.
  19  *
  20  * THIS SOFTWARE IS EXPERIMENTAL AND IS KNOWN TO HAVE BUGS, SOME OF
  21  * WHICH MAY HAVE SERIOUS CONSEQUENCES.  CARNEGIE MELLON PROVIDES THIS
  22  * SOFTWARE IN ITS ``AS IS'' CONDITION, AND ANY EXPRESS OR IMPLIED
  23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  * DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  28  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
  32  * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
  33  * DAMAGE.
  34  *
  35  * Carnegie Mellon encourages (but does not require) users of this
  36  * software to return any improvements or extensions that they make,
  37  * and to grant Carnegie Mellon the rights to redistribute these
  38  * changes without encumbrance.
  39  */
  40 /*
  41  * H-FSC is described in Proceedings of SIGCOMM'97,
  42  * "A Hierarchical Fair Service Curve Algorithm for Link-Sharing,
  43  * Real-Time and Priority Service"
  44  * by Ion Stoica, Hui Zhang, and T. S. Eugene Ng.
  45  *
  46  * Oleg Cherevko <olwi@aq.ml.com.ua> added the upperlimit for link-sharing.
  47  * when a class has an upperlimit, the fit-time is computed from the
  48  * upperlimit service curve.  the link-sharing scheduler does not schedule
  49  * a class whose fit-time exceeds the current time.
  50  */
  51
  52 #include <linux/kernel.h>
  53 #include <linux/config.h>
  54 #include <linux/module.h>
  55 #include <linux/types.h>
  56 #include <linux/errno.h>
  57 #include <linux/jiffies.h>
  58 #include <linux/compiler.h>
  59 #include <linux/spinlock.h>
  60 #include <linux/skbuff.h>
  61 #include <linux/string.h>
  62 #include <linux/slab.h>
  63 #include <linux/timer.h>
  64 #include <linux/list.h>
  65 #include <linux/init.h>
  66 #include <linux/netdevice.h>
  67 #include <linux/rtnetlink.h>
  68 #include <linux/pkt_sched.h>
  69 #include <net/pkt_sched.h>
  70 #include <net/pkt_cls.h>
  71 #include <asm/system.h>
  72 #include <asm/div64.h>
  73
  74 #define HFSC_DEBUG 1
  75
  76 /*
  77  * kernel internal service curve representation:
  78  *   coordinates are given by 64 bit unsigned integers.
  79  *   x-axis: unit is clock count.
  80  *   y-axis: unit is byte.
  81  *
  82  *   The service curve parameters are converted to the internal
  83  *   representation. The slope values are scaled to avoid overflow.
  84  *   the inverse slope values as well as the y-projection of the 1st
  85  *   segment are kept in order to to avoid 64-bit divide operations
  86  *   that are expensive on 32-bit architectures.
  87  */
  88
  89 struct internal_sc
  90 {
  91         u64     sm1;    /* scaled slope of the 1st segment */
  92         u64     ism1;   /* scaled inverse-slope of the 1st segment */
  93         u64     dx;     /* the x-projection of the 1st segment */
  94         u64     dy;     /* the y-projection of the 1st segment */
  95         u64     sm2;    /* scaled slope of the 2nd segment */
  96         u64     ism2;   /* scaled inverse-slope of the 2nd segment */
  97 };
  98
  99 /* runtime service curve */
 100 struct runtime_sc
 101 {
 102         u64     x;      /* current starting position on x-axis */
 103         u64     y;      /* current starting position on y-axis */
 104         u64     sm1;    /* scaled slope of the 1st segment */
 105         u64     ism1;   /* scaled inverse-slope of the 1st segment */
 106         u64     dx;     /* the x-projection of the 1st segment */
 107         u64     dy;     /* the y-projection of the 1st segment */
 108         u64     sm2;    /* scaled slope of the 2nd segment */
 109         u64     ism2;   /* scaled inverse-slope of the 2nd segment */
 110 };
 111
 112 enum hfsc_class_flags
 113 {
 114         HFSC_RSC = 0x1,
 115         HFSC_FSC = 0x2,
 116         HFSC_USC = 0x4
 117 };
 118
 119 struct hfsc_class
 120 {
 121         u32             classid;        /* class id */
 122         unsigned int    refcnt;         /* usage count */
 123
 124         struct tc_stats stats;          /* generic statistics */
 125         unsigned int    level;          /* class level in hierarchy */
 126         struct tcf_proto *filter_list;  /* filter list */
 127         unsigned int    filter_cnt;     /* filter count */
 128
 129         struct hfsc_sched *sched;       /* scheduler data */
 130         struct hfsc_class *cl_parent;   /* parent class */
 131         struct list_head siblings;      /* sibling classes */
 132         struct list_head children;      /* child classes */
 133         struct Qdisc    *qdisc;         /* leaf qdisc */
 134
 135         struct list_head actlist;       /* active children list */
 136         struct list_head alist;         /* active children list member */
 137         struct list_head ellist;        /* eligible list member */
 138         struct list_head hlist;         /* hash list member */
 139         struct list_head dlist;         /* drop list member */
 140
 141         u64     cl_total;               /* total work in bytes */
 142         u64     cl_cumul;               /* cumulative work in bytes done by
 143                                            real-time criteria */
 144
 145         u64     cl_d;                   /* deadline*/
 146         u64     cl_e;                   /* eligible time */
 147         u64     cl_vt;                  /* virtual time */
 148         u64     cl_f;                   /* time when this class will fit for
 149                                            link-sharing, max(myf, cfmin) */
 150         u64     cl_myf;                 /* my fit-time (calculated from this
 151                                            class's own upperlimit curve) */
 152         u64     cl_myfadj;              /* my fit-time adjustment (to cancel
 153                                            history dependence) */
 154         u64     cl_cfmin;               /* earliest children's fit-time (used
 155                                            with cl_myf to obtain cl_f) */
 156         u64     cl_cvtmin;              /* minimal virtual time among the
 157                                            children fit for link-sharing
 158                                            (monotonic within a period) */
 159         u64     cl_vtadj;               /* intra-period cumulative vt
 160                                            adjustment */
 161         u64     cl_vtoff;               /* inter-period cumulative vt offset */
 162         u64     cl_cvtmax;              /* max child's vt in the last period */
 163
 164         struct internal_sc cl_rsc;      /* internal real-time service curve */
 165         struct internal_sc cl_fsc;      /* internal fair service curve */
 166         struct internal_sc cl_usc;      /* internal upperlimit service curve */
 167         struct runtime_sc cl_deadline;  /* deadline curve */
 168         struct runtime_sc cl_eligible;  /* eligible curve */
 169         struct runtime_sc cl_virtual;   /* virtual curve */
 170         struct runtime_sc cl_ulimit;    /* upperlimit curve */
 171
 172         unsigned long   cl_flags;       /* which curves are valid */
 173         unsigned long   cl_vtperiod;    /* vt period sequence number */
 174         unsigned long   cl_parentperiod;/* parent's vt period sequence number*/
 175         unsigned long   cl_nactive;     /* number of active children */
 176 };
 177
 178 #define HFSC_HSIZE      16
 179
 180 struct hfsc_sched
 181 {
 182         u16     defcls;                         /* default class id */
 183         struct hfsc_class root;                 /* root class */
 184         struct list_head clhash[HFSC_HSIZE];    /* class hash */
 185         struct list_head eligible;              /* eligible list */
 186         struct list_head droplist;              /* active leaf class list (for
 187                                                    dropping) */
 188         struct sk_buff_head requeue;            /* requeued packet */
 189         struct timer_list wd_timer;             /* watchdog timer */
 190 };
 191
 192 /*
 193  * macros
 194  */
 195 #if PSCHED_CLOCK_SOURCE == PSCHED_GETTIMEOFDAY
 196 #include <linux/time.h>
 197 #undef PSCHED_GET_TIME
 198 #define PSCHED_GET_TIME(stamp)                                          \
 199 do {                                                                    \
 200         struct timeval tv;                                              \
 201         do_gettimeofday(&tv);                                           \
 202         (stamp) = 1000000ULL * tv.tv_sec + tv.tv_usec;                  \
 203 } while (0)
 204 #endif
 205
 206 #if HFSC_DEBUG
 207 #define ASSERT(cond)                                                    \
 208 do {                                                                    \
 209         if (unlikely(!(cond)))                                          \
 210                 printk("assertion %s failed at %s:%i (%s)\n",           \
 211                        #cond, __FILE__, __LINE__, __FUNCTION__);        \
 212 } while (0)
 213 #else
 214 #define ASSERT(cond)
 215 #endif /* HFSC_DEBUG */
 216
 217 #define HT_INFINITY     0xffffffffffffffffULL   /* infinite time value */
 218
 219
 220 /*
 221  * eligible list holds backlogged classes being sorted by their eligible times.
 222  * there is one eligible list per hfsc instance.
 223  */
 224
 225 static void
 226 ellist_insert(struct hfsc_class *cl)
 227 {
 228         struct list_head *head = &cl->sched->eligible;
 229         struct hfsc_class *p;
 230
 231         /* check the last entry first */
 232         if (list_empty(head) ||
 233             ((p = list_entry(head->prev, struct hfsc_class, ellist)) &&
 234              p->cl_e <= cl->cl_e)) {
 235                 list_add_tail(&cl->ellist, head);
 236                 return;
 237         }
 238
 239         list_for_each_entry(p, head, ellist) {
 240                 if (cl->cl_e < p->cl_e) {
 241                         /* insert cl before p */
 242                         list_add_tail(&cl->ellist, &p->ellist);
 243                         return;
 244                 }
 245         }
 246         ASSERT(0); /* should not reach here */
 247 }
 248
 249 static inline void
 250 ellist_remove(struct hfsc_class *cl)
 251 {
 252         list_del(&cl->ellist);
 253 }
 254
 255 static void
 256 ellist_update(struct hfsc_class *cl)
 257 {
 258         struct list_head *head = &cl->sched->eligible;
 259         struct hfsc_class *p, *last;
 260
 261         /*
 262          * the eligible time of a class increases monotonically.
 263          * if the next entry has a larger eligible time, nothing to do.
 264          */
 265         if (cl->ellist.next == head ||
 266             ((p = list_entry(cl->ellist.next, struct hfsc_class, ellist)) &&
 267              cl->cl_e <= p->cl_e))
 268                 return;
 269
 270         /* check the last entry */
 271         last = list_entry(head->prev, struct hfsc_class, ellist);
 272         if (last->cl_e <= cl->cl_e) {
 273                 list_move_tail(&cl->ellist, head);
 274                 return;
 275         }
 276
 277         /*
 278          * the new position must be between the next entry
 279          * and the last entry
 280          */
 281         list_for_each_entry_continue(p, head, ellist) {
 282                 if (cl->cl_e < p->cl_e) {
 283                         list_move_tail(&cl->ellist, &p->ellist);
 284                         return;
 285                 }
 286         }
 287         ASSERT(0); /* should not reach here */
 288 }
 289
 290 /* find the class with the minimum deadline among the eligible classes */
 291 static inline struct hfsc_class *
 292 ellist_get_mindl(struct list_head *head, u64 cur_time)
 293 {
 294         struct hfsc_class *p, *cl = NULL;
 295
 296         list_for_each_entry(p, head, ellist) {
 297                 if (p->cl_e > cur_time)
 298                         break;
 299                 if (cl == NULL || p->cl_d < cl->cl_d)
 300                         cl = p;
 301         }
 302         return cl;
 303 }
 304
 305 /* find the class with minimum eligible time among the eligible classes */
 306 static inline struct hfsc_class *
 307 ellist_get_minel(struct list_head *head)
 308 {
 309         if (list_empty(head))
 310                 return NULL;
 311         return list_entry(head->next, struct hfsc_class, ellist);
 312 }
 313
 314 /*
 315  * active children list holds backlogged child classes being sorted
 316  * by their virtual time. each intermediate class has one active
 317  * children list.
 318  */
 319 static void
 320 actlist_insert(struct hfsc_class *cl)
 321 {
 322         struct list_head *head = &cl->cl_parent->actlist;
 323         struct hfsc_class *p;
 324
 325         /* check the last entry first */
 326         if (list_empty(head) ||
 327             ((p = list_entry(head->prev, struct hfsc_class, alist)) &&
 328              p->cl_vt <= cl->cl_vt)) {
 329                 list_add_tail(&cl->alist, head);
 330                 return;
 331         }
 332
 333         list_for_each_entry(p, head, alist) {
 334                 if (cl->cl_vt < p->cl_vt) {
 335                         /* insert cl before p */
 336                         list_add_tail(&cl->alist, &p->alist);
 337                         return;
 338                 }
 339         }
 340         ASSERT(0); /* should not reach here */
 341 }
 342
 343 static inline void
 344 actlist_remove(struct hfsc_class *cl)
 345 {
 346         list_del(&cl->alist);
 347 }
 348
 349 static void
 350 actlist_update(struct hfsc_class *cl)
 351 {
 352         struct list_head *head = &cl->cl_parent->actlist;
 353         struct hfsc_class *p, *last;
 354
 355         /*
 356          * the virtual time of a class increases monotonically.
 357          * if the next entry has a larger virtual time, nothing to do.
 358          */
 359         if (cl->alist.next == head ||
 360             ((p = list_entry(cl->alist.next, struct hfsc_class, alist)) &&
 361              cl->cl_vt <= p->cl_vt))
 362                 return;
 363
 364         /* check the last entry */
 365         last = list_entry(head->prev, struct hfsc_class, alist);
 366         if (last->cl_vt <= cl->cl_vt) {
 367                 list_move_tail(&cl->alist, head);
 368                 return;
 369         }
 370
 371         /*
 372          * the new position must be between the next entry
 373          * and the last entry
 374          */
 375         list_for_each_entry_continue(p, head, alist) {
 376                 if (cl->cl_vt < p->cl_vt) {
 377                         list_move_tail(&cl->alist, &p->alist);
 378                         return;
 379                 }
 380         }
 381         ASSERT(0); /* should not reach here */
 382 }
 383
 384 static inline struct hfsc_class *
 385 actlist_firstfit(struct hfsc_class *cl, u64 cur_time)
 386 {
 387         struct hfsc_class *p;
 388
 389         list_for_each_entry(p, &cl->actlist, alist) {
 390                 if (p->cl_f <= cur_time) {
 391                         return p;
 392                 }
 393         }
 394         return NULL;
 395 }
 396
 397 /*
 398  * get the leaf class with the minimum vt in the hierarchy
 399  */
 400 static struct hfsc_class *
 401 actlist_get_minvt(struct hfsc_class *cl, u64 cur_time)
 402 {
 403         /* if root-class's cfmin is bigger than cur_time nothing to do */
 404         if (cl->cl_cfmin > cur_time)
 405                 return NULL;
 406
 407         while (cl->level > 0) {
 408                 cl = actlist_firstfit(cl, cur_time);
 409                 if (cl == NULL)
 410                         return NULL;
 411                 /*
 412                  * update parent's cl_cvtmin.
 413                  */
 414                 if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
 415                         cl->cl_parent->cl_cvtmin = cl->cl_vt;
 416         }
 417         return cl;
 418 }
 419
 420 /*
 421  * service curve support functions
 422  *
 423  *  external service curve parameters
 424  *      m: bps
 425  *      d: us
 426  *  internal service curve parameters
 427  *      sm: (bytes/psched_us) << SM_SHIFT
 428  *      ism: (psched_us/byte) << ISM_SHIFT
 429  *      dx: psched_us
 430  *
 431  * Time source resolution
 432  *  PSCHED_JIFFIES: for 48<=HZ<=1534 resolution is between 0.63us and 1.27us.
 433  *  PSCHED_CPU: resolution is between 0.5us and 1us.
 434  *  PSCHED_GETTIMEOFDAY: resolution is exactly 1us.
 435  *
 436  * sm and ism are scaled in order to keep effective digits.
 437  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
 438  * digits in decimal using the following table.
 439  *
 440  * Note: We can afford the additional accuracy (altq hfsc keeps at most
 441  * 3 effective digits) thanks to the fact that linux clock is bounded
 442  * much more tightly.
 443  *
 444  *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
 445  *  ------------+-------------------------------------------------------
 446  *  bytes/0.5us   6.25e-3    62.5e-3    625e-3     6250e-e    62500e-3
 447  *  bytes/us      12.5e-3    125e-3     1250e-3    12500e-3   125000e-3
 448  *  bytes/1.27us  15.875e-3  158.75e-3  1587.5e-3  15875e-3   158750e-3
 449  *
 450  *  0.5us/byte    160        16         1.6        0.16       0.016
 451  *  us/byte       80         8          0.8        0.08       0.008
 452  *  1.27us/byte   63         6.3        0.63       0.063      0.0063
 453  */
 454 #define SM_SHIFT        20
 455 #define ISM_SHIFT       18
 456
 457 #define SM_MASK         ((1ULL << SM_SHIFT) - 1)
 458 #define ISM_MASK        ((1ULL << ISM_SHIFT) - 1)
 459
 460 static inline u64
 461 seg_x2y(u64 x, u64 sm)
 462 {
 463         u64 y;
 464
 465         /*
 466          * compute
 467          *      y = x * sm >> SM_SHIFT
 468          * but divide it for the upper and lower bits to avoid overflow
 469          */
 470         y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
 471         return y;
 472 }
 473
 474 static inline u64
 475 seg_y2x(u64 y, u64 ism)
 476 {
 477         u64 x;
 478
 479         if (y == 0)
 480                 x = 0;
 481         else if (ism == HT_INFINITY)
 482                 x = HT_INFINITY;
 483         else {
 484                 x = (y >> ISM_SHIFT) * ism
 485                     + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
 486         }
 487         return x;
 488 }
 489
 490 /* Convert m (bps) into sm (bytes/psched us) */
 491 static u64
 492 m2sm(u32 m)
 493 {
 494         u64 sm;
 495
 496         sm = ((u64)m << SM_SHIFT);
 497         sm += PSCHED_JIFFIE2US(HZ) - 1;
 498         do_div(sm, PSCHED_JIFFIE2US(HZ));
 499         return sm;
 500 }
 501
 502 /* convert m (bps) into ism (psched us/byte) */
 503 static u64
 504 m2ism(u32 m)
 505 {
 506         u64 ism;
 507
 508         if (m == 0)
 509                 ism = HT_INFINITY;
 510         else {
 511                 ism = ((u64)PSCHED_JIFFIE2US(HZ) << ISM_SHIFT);
 512                 ism += m - 1;
 513                 do_div(ism, m);
 514         }
 515         return ism;
 516 }
 517
 518 /* convert d (us) into dx (psched us) */
 519 static u64
 520 d2dx(u32 d)
 521 {
 522         u64 dx;
 523
 524         dx = ((u64)d * PSCHED_JIFFIE2US(HZ));
 525         dx += 1000000 - 1;
 526         do_div(dx, 1000000);
 527         return dx;
 528 }
 529
 530 /* convert sm (bytes/psched us) into m (bps) */
 531 static u32
 532 sm2m(u64 sm)
 533 {
 534         u64 m;
 535
 536         m = (sm * PSCHED_JIFFIE2US(HZ)) >> SM_SHIFT;
 537         return (u32)m;
 538 }
 539
 540 /* convert dx (psched us) into d (us) */
 541 static u32
 542 dx2d(u64 dx)
 543 {
 544         u64 d;
 545
 546         d = dx * 1000000;
 547         do_div(d, PSCHED_JIFFIE2US(HZ));
 548         return (u32)d;
 549 }
 550
 551 static void
 552 sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
 553 {
 554         isc->sm1  = m2sm(sc->m1);
 555         isc->ism1 = m2ism(sc->m1);
 556         isc->dx   = d2dx(sc->d);
 557         isc->dy   = seg_x2y(isc->dx, isc->sm1);
 558         isc->sm2  = m2sm(sc->m2);
 559         isc->ism2 = m2ism(sc->m2);
 560 }
 561
 562 /*
 563  * initialize the runtime service curve with the given internal
 564  * service curve starting at (x, y).
 565  */
 566 static void
 567 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 568 {
 569         rtsc->x    = x;
 570         rtsc->y    = y;
 571         rtsc->sm1  = isc->sm1;
 572         rtsc->ism1 = isc->ism1;
 573         rtsc->dx   = isc->dx;
 574         rtsc->dy   = isc->dy;
 575         rtsc->sm2  = isc->sm2;
 576         rtsc->ism2 = isc->ism2;
 577 }
 578
 579 /*
 580  * calculate the y-projection of the runtime service curve by the
 581  * given x-projection value
 582  */
 583 static u64
 584 rtsc_y2x(struct runtime_sc *rtsc, u64 y)
 585 {
 586         u64 x;
 587
 588         if (y < rtsc->y)
 589                 x = rtsc->x;
 590         else if (y <= rtsc->y + rtsc->dy) {
 591                 /* x belongs to the 1st segment */
 592                 if (rtsc->dy == 0)
 593                         x = rtsc->x + rtsc->dx;
 594                 else
 595                         x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
 596         } else {
 597                 /* x belongs to the 2nd segment */
 598                 x = rtsc->x + rtsc->dx
 599                     + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
 600         }
 601         return x;
 602 }
 603
 604 static u64
 605 rtsc_x2y(struct runtime_sc *rtsc, u64 x)
 606 {
 607         u64 y;
 608
 609         if (x <= rtsc->x)
 610                 y = rtsc->y;
 611         else if (x <= rtsc->x + rtsc->dx)
 612                 /* y belongs to the 1st segment */
 613                 y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
 614         else
 615                 /* y belongs to the 2nd segment */
 616                 y = rtsc->y + rtsc->dy
 617                     + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
 618         return y;
 619 }
 620
 621 /*
 622  * update the runtime service curve by taking the minimum of the current
 623  * runtime service curve and the service curve starting at (x, y).
 624  */
 625 static void
 626 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 627 {
 628         u64 y1, y2, dx, dy;
 629         u32 dsm;
 630
 631         if (isc->sm1 <= isc->sm2) {
 632                 /* service curve is convex */
 633                 y1 = rtsc_x2y(rtsc, x);
 634                 if (y1 < y)
 635                         /* the current rtsc is smaller */
 636                         return;
 637                 rtsc->x = x;
 638                 rtsc->y = y;
 639                 return;
 640         }
 641
 642         /*
 643          * service curve is concave
 644          * compute the two y values of the current rtsc
 645          *      y1: at x
 646          *      y2: at (x + dx)
 647          */
 648         y1 = rtsc_x2y(rtsc, x);
 649         if (y1 <= y) {
 650                 /* rtsc is below isc, no change to rtsc */
 651                 return;
 652         }
 653
 654         y2 = rtsc_x2y(rtsc, x + isc->dx);
 655         if (y2 >= y + isc->dy) {
 656                 /* rtsc is above isc, replace rtsc by isc */
 657                 rtsc->x = x;
 658                 rtsc->y = y;
 659                 rtsc->dx = isc->dx;
 660                 rtsc->dy = isc->dy;
 661                 return;
 662         }
 663
 664         /*
 665          * the two curves intersect
 666          * compute the offsets (dx, dy) using the reverse
 667          * function of seg_x2y()
 668          *      seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
 669          */
 670         dx = (y1 - y) << SM_SHIFT;
 671         dsm = isc->sm1 - isc->sm2;
 672         do_div(dx, dsm);
 673         /*
 674          * check if (x, y1) belongs to the 1st segment of rtsc.
 675          * if so, add the offset.
 676          */
 677         if (rtsc->x + rtsc->dx > x)
 678                 dx += rtsc->x + rtsc->dx - x;
 679         dy = seg_x2y(dx, isc->sm1);
 680
 681         rtsc->x = x;
 682         rtsc->y = y;
 683         rtsc->dx = dx;
 684         rtsc->dy = dy;
 685         return;
 686 }
 687
 688 static void
 689 init_ed(struct hfsc_class *cl, unsigned int next_len)
 690 {
 691         u64 cur_time;
 692
 693         PSCHED_GET_TIME(cur_time);
 694
 695         /* update the deadline curve */
 696         rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
 697
 698         /*
 699          * update the eligible curve.
 700          * for concave, it is equal to the deadline curve.
 701          * for convex, it is a linear curve with slope m2.
 702          */
 703         cl->cl_eligible = cl->cl_deadline;
 704         if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
 705                 cl->cl_eligible.dx = 0;
 706                 cl->cl_eligible.dy = 0;
 707         }
 708
 709         /* compute e and d */
 710         cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
 711         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 712
 713         ellist_insert(cl);
 714 }
 715
 716 static void
 717 update_ed(struct hfsc_class *cl, unsigned int next_len)
 718 {
 719         cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
 720         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 721
 722         ellist_update(cl);
 723 }
 724
 725 static inline void
 726 update_d(struct hfsc_class *cl, unsigned int next_len)
 727 {
 728         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 729 }
 730
 731 static void
 732 update_cfmin(struct hfsc_class *cl)
 733 {
 734         struct hfsc_class *p;
 735         u64 cfmin;
 736
 737         if (list_empty(&cl->actlist)) {
 738                 cl->cl_cfmin = 0;
 739                 return;
 740         }
 741         cfmin = HT_INFINITY;
 742         list_for_each_entry(p, &cl->actlist, alist) {
 743                 if (p->cl_f == 0) {
 744                         cl->cl_cfmin = 0;
 745                         return;
 746                 }
 747                 if (p->cl_f < cfmin)
 748                         cfmin = p->cl_f;
 749         }
 750         cl->cl_cfmin = cfmin;
 751 }
 752
 753 static void
 754 init_vf(struct hfsc_class *cl, unsigned int len)
 755 {
 756         struct hfsc_class *max_cl, *p;
 757         u64 vt, f, cur_time;
 758         int go_active;
 759
 760         cur_time = 0;
 761         go_active = 1;
 762         for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
 763                 if (go_active && cl->cl_nactive++ == 0)
 764                         go_active = 1;
 765                 else
 766                         go_active = 0;
 767
 768                 if (go_active) {
 769                         if (!list_empty(&cl->cl_parent->actlist)) {
 770                                 max_cl = list_entry(cl->cl_parent->actlist.prev,
 771                                                     struct hfsc_class, alist);
 772                                 /*
 773                                  * set vt to the average of the min and max
 774                                  * classes.  if the parent's period didn't
 775                                  * change, don't decrease vt of the class.
 776                                  */
 777                                 vt = max_cl->cl_vt;
 778                                 if (cl->cl_parent->cl_cvtmin != 0)
 779                                         vt = (cl->cl_parent->cl_cvtmin + vt)/2;
 780
 781                                 if (cl->cl_parent->cl_vtperiod !=
 782                                     cl->cl_parentperiod || vt > cl->cl_vt)
 783                                         cl->cl_vt = vt;
 784                         } else {
 785                                 /*
 786                                  * first child for a new parent backlog period.
 787                                  * add parent's cvtmax to vtoff of children
 788                                  * to make a new vt (vtoff + vt) larger than
 789                                  * the vt in the last period for all children.
 790                                  */
 791                                 vt = cl->cl_parent->cl_cvtmax;
 792                                 list_for_each_entry(p, &cl->cl_parent->children,
 793                                                                        siblings)
 794                                         p->cl_vtoff += vt;
 795                                 cl->cl_vt = 0;
 796                                 cl->cl_parent->cl_cvtmax = 0;
 797                                 cl->cl_parent->cl_cvtmin = 0;
 798                         }
 799
 800                         /* update the virtual curve */
 801                         vt = cl->cl_vt + cl->cl_vtoff;
 802                         rtsc_min(&cl->cl_virtual, &cl->cl_fsc, vt,
 803                                                       cl->cl_total);
 804                         if (cl->cl_virtual.x == vt) {
 805                                 cl->cl_virtual.x -= cl->cl_vtoff;
 806                                 cl->cl_vtoff = 0;
 807                         }
 808                         cl->cl_vtadj = 0;
 809
 810                         cl->cl_vtperiod++;  /* increment vt period */
 811                         cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
 812                         if (cl->cl_parent->cl_nactive == 0)
 813                                 cl->cl_parentperiod++;
 814                         cl->cl_f = 0;
 815
 816                         actlist_insert(cl);
 817
 818                         if (cl->cl_flags & HFSC_USC) {
 819                                 /* class has upper limit curve */
 820                                 if (cur_time == 0)
 821                                         PSCHED_GET_TIME(cur_time);
 822
 823                                 /* update the ulimit curve */
 824                                 rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
 825                                          cl->cl_total);
 826                                 /* compute myf */
 827                                 cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
 828                                                       cl->cl_total);
 829                                 cl->cl_myfadj = 0;
 830                         }
 831                 }
 832
 833                 f = max(cl->cl_myf, cl->cl_cfmin);
 834                 if (f != cl->cl_f) {
 835                         cl->cl_f = f;
 836                         update_cfmin(cl->cl_parent);
 837                 }
 838         }
 839 }
 840
 841 static void
 842 update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
 843 {
 844         u64 f; /* , myf_bound, delta; */
 845         int go_passive = 0;
 846
 847         if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
 848                 go_passive = 1;
 849
 850         for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
 851                 cl->cl_total += len;
 852
 853                 if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
 854                         continue;
 855
 856                 if (go_passive && --cl->cl_nactive == 0)
 857                         go_passive = 1;
 858                 else
 859                         go_passive = 0;
 860
 861                 if (go_passive) {
 862                         /* no more active child, going passive */
 863
 864                         /* update cvtmax of the parent class */
 865                         if (cl->cl_vt > cl->cl_parent->cl_cvtmax)
 866                                 cl->cl_parent->cl_cvtmax = cl->cl_vt;
 867
 868                         /* remove this class from the vt list */
 869                         actlist_remove(cl);
 870
 871                         update_cfmin(cl->cl_parent);
 872
 873                         continue;
 874                 }
 875
 876                 /*
 877                  * update vt and f
 878                  */
 879                 cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total)
 880                             - cl->cl_vtoff + cl->cl_vtadj;
 881
 882                 /*
 883                  * if vt of the class is smaller than cvtmin,
 884                  * the class was skipped in the past due to non-fit.
 885                  * if so, we need to adjust vtadj.
 886                  */
 887                 if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
 888                         cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
 889                         cl->cl_vt = cl->cl_parent->cl_cvtmin;
 890                 }
 891
 892                 /* update the vt list */
 893                 actlist_update(cl);
 894
 895                 if (cl->cl_flags & HFSC_USC) {
 896                         cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
 897                                                               cl->cl_total);
 898 #if 0
 899                         /*
 900                          * This code causes classes to stay way under their
 901                          * limit when multiple classes are used at gigabit
 902                          * speed. needs investigation. -kaber
 903                          */
 904                         /*
 905                          * if myf lags behind by more than one clock tick
 906                          * from the current time, adjust myfadj to prevent
 907                          * a rate-limited class from going greedy.
 908                          * in a steady state under rate-limiting, myf
 909                          * fluctuates within one clock tick.
 910                          */
 911                         myf_bound = cur_time - PSCHED_JIFFIE2US(1);
 912                         if (cl->cl_myf < myf_bound) {
 913                                 delta = cur_time - cl->cl_myf;
 914                                 cl->cl_myfadj += delta;
 915                                 cl->cl_myf += delta;
 916                         }
 917 #endif
 918                 }
 919
 920                 f = max(cl->cl_myf, cl->cl_cfmin);
 921                 if (f != cl->cl_f) {
 922                         cl->cl_f = f;
 923                         update_cfmin(cl->cl_parent);
 924                 }
 925         }
 926 }
 927
 928 static void
 929 set_active(struct hfsc_class *cl, unsigned int len)
 930 {
 931         if (cl->cl_flags & HFSC_RSC)
 932                 init_ed(cl, len);
 933         if (cl->cl_flags & HFSC_FSC)
 934                 init_vf(cl, len);
 935
 936         list_add_tail(&cl->dlist, &cl->sched->droplist);
 937 }
 938
 939 static void
 940 set_passive(struct hfsc_class *cl)
 941 {
 942         if (cl->cl_flags & HFSC_RSC)
 943                 ellist_remove(cl);
 944
 945         list_del(&cl->dlist);
 946
 947         /*
 948          * actlist is now handled in update_vf() so that update_vf(cl, 0, 0)
 949          * needs to be called explicitly to remove a class from actlist
 950          */
 951 }
 952
 953 /*
 954  * hack to get length of first packet in queue.
 955  */
 956 static unsigned int
 957 qdisc_peek_len(struct Qdisc *sch)
 958 {
 959         struct sk_buff *skb;
 960         unsigned int len;
 961
 962         skb = sch->dequeue(sch);
 963         if (skb == NULL) {
 964                 if (net_ratelimit())
 965                         printk("qdisc_peek_len: non work-conserving qdisc ?\n");
 966                 return 0;
 967         }
 968         len = skb->len;
 969         if (unlikely(sch->ops->requeue(skb, sch) != NET_XMIT_SUCCESS)) {
 970                 if (net_ratelimit())
 971                         printk("qdisc_peek_len: failed to requeue\n");
 972                 return 0;
 973         }
 974         return len;
 975 }
 976
 977 static void
 978 hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
 979 {
 980         unsigned int len = cl->qdisc->q.qlen;
 981
 982         qdisc_reset(cl->qdisc);
 983         if (len > 0) {
 984                 update_vf(cl, 0, 0);
 985                 set_passive(cl);
 986                 sch->q.qlen -= len;
 987         }
 988 }
 989
 990 static void
 991 hfsc_adjust_levels(struct hfsc_class *cl)
 992 {
 993         struct hfsc_class *p;
 994         unsigned int level;
 995
 996         do {
 997                 level = 0;
 998                 list_for_each_entry(p, &cl->children, siblings) {
 999                         if (p->level > level)
1000                                 level = p->level;
1001                 }
1002                 cl->level = level + 1;
1003         } while ((cl = cl->cl_parent) != NULL);
1004 }
1005
1006 static inline unsigned int
1007 hfsc_hash(u32 h)
1008 {
1009         h ^= h >> 8;
1010         h ^= h >> 4;
1011
1012         return h & (HFSC_HSIZE - 1);
1013 }
1014
1015 static inline struct hfsc_class *
1016 hfsc_find_class(u32 classid, struct Qdisc *sch)
1017 {
1018         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1019         struct hfsc_class *cl;
1020
1021         list_for_each_entry(cl, &q->clhash[hfsc_hash(classid)], hlist) {
1022                 if (cl->classid == classid)
1023                         return cl;
1024         }
1025         return NULL;
1026 }
1027
1028 static void
1029 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
1030                 u64 cur_time)
1031 {
1032         sc2isc(rsc, &cl->cl_rsc);
1033         rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
1034         cl->cl_eligible = cl->cl_deadline;
1035         if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
1036                 cl->cl_eligible.dx = 0;
1037                 cl->cl_eligible.dy = 0;
1038         }
1039         cl->cl_flags |= HFSC_RSC;
1040 }
1041
1042 static void
1043 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
1044 {
1045         sc2isc(fsc, &cl->cl_fsc);
1046         rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
1047         cl->cl_flags |= HFSC_FSC;
1048 }
1049
1050 static void
1051 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
1052                 u64 cur_time)
1053 {
1054         sc2isc(usc, &cl->cl_usc);
1055         rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
1056         cl->cl_flags |= HFSC_USC;
1057 }
1058
1059 static int
1060 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
1061                   struct rtattr **tca, unsigned long *arg)
1062 {
1063         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1064         struct hfsc_class *cl = (struct hfsc_class *)*arg;
1065         struct hfsc_class *parent = NULL;
1066         struct rtattr *opt = tca[TCA_OPTIONS-1];
1067         struct rtattr *tb[TCA_HFSC_MAX];
1068         struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
1069         u64 cur_time;
1070
1071         if (opt == NULL ||
1072             rtattr_parse(tb, TCA_HFSC_MAX, RTA_DATA(opt), RTA_PAYLOAD(opt)))
1073                 return -EINVAL;
1074
1075         if (tb[TCA_HFSC_RSC-1]) {
1076                 if (RTA_PAYLOAD(tb[TCA_HFSC_RSC-1]) < sizeof(*rsc))
1077                         return -EINVAL;
1078                 rsc = RTA_DATA(tb[TCA_HFSC_RSC-1]);
1079                 if (rsc->m1 == 0 && rsc->m2 == 0)
1080                         rsc = NULL;
1081         }
1082
1083         if (tb[TCA_HFSC_FSC-1]) {
1084                 if (RTA_PAYLOAD(tb[TCA_HFSC_FSC-1]) < sizeof(*fsc))
1085                         return -EINVAL;
1086                 fsc = RTA_DATA(tb[TCA_HFSC_FSC-1]);
1087                 if (fsc->m1 == 0 && fsc->m2 == 0)
1088                         fsc = NULL;
1089         }
1090
1091         if (tb[TCA_HFSC_USC-1]) {
1092                 if (RTA_PAYLOAD(tb[TCA_HFSC_USC-1]) < sizeof(*usc))
1093                         return -EINVAL;
1094                 usc = RTA_DATA(tb[TCA_HFSC_USC-1]);
1095                 if (usc->m1 == 0 && usc->m2 == 0)
1096                         usc = NULL;
1097         }
1098
1099         if (cl != NULL) {
1100                 if (parentid) {
1101                         if (cl->cl_parent && cl->cl_parent->classid != parentid)
1102                                 return -EINVAL;
1103                         if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
1104                                 return -EINVAL;
1105                 }
1106                 PSCHED_GET_TIME(cur_time);
1107
1108                 sch_tree_lock(sch);
1109                 if (rsc != NULL)
1110                         hfsc_change_rsc(cl, rsc, cur_time);
1111                 if (fsc != NULL)
1112                         hfsc_change_fsc(cl, fsc);
1113                 if (usc != NULL)
1114                         hfsc_change_usc(cl, usc, cur_time);
1115
1116                 if (cl->qdisc->q.qlen != 0) {
1117                         if (cl->cl_flags & HFSC_RSC)
1118                                 update_ed(cl, qdisc_peek_len(cl->qdisc));
1119                         if (cl->cl_flags & HFSC_FSC)
1120                                 update_vf(cl, 0, cur_time);
1121                 }
1122                 sch_tree_unlock(sch);
1123
1124 #ifdef CONFIG_NET_ESTIMATOR
1125                 if (tca[TCA_RATE-1]) {
1126                         qdisc_kill_estimator(&cl->stats);
1127                         qdisc_new_estimator(&cl->stats, tca[TCA_RATE-1]);
1128                 }
1129 #endif
1130                 return 0;
1131         }
1132
1133         if (parentid == TC_H_ROOT)
1134                 return -EEXIST;
1135
1136         parent = &q->root;
1137         if (parentid) {
1138                 parent = hfsc_find_class(parentid, sch);
1139                 if (parent == NULL)
1140                         return -ENOENT;
1141         }
1142
1143         if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1144                 return -EINVAL;
1145         if (hfsc_find_class(classid, sch))
1146                 return -EEXIST;
1147
1148         if (rsc == NULL && fsc == NULL)
1149                 return -EINVAL;
1150
1151         cl = kmalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1152         if (cl == NULL)
1153                 return -ENOBUFS;
1154         memset(cl, 0, sizeof(struct hfsc_class));
1155
1156         if (rsc != NULL)
1157                 hfsc_change_rsc(cl, rsc, 0);
1158         if (fsc != NULL)
1159                 hfsc_change_fsc(cl, fsc);
1160         if (usc != NULL)
1161                 hfsc_change_usc(cl, usc, 0);
1162
1163         cl->refcnt    = 1;
1164         cl->classid   = classid;
1165         cl->sched     = q;
1166         cl->cl_parent = parent;
1167         cl->qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1168         if (cl->qdisc == NULL)
1169                 cl->qdisc = &noop_qdisc;
1170         cl->stats.lock = &sch->dev->queue_lock;
1171         INIT_LIST_HEAD(&cl->children);
1172         INIT_LIST_HEAD(&cl->actlist);
1173
1174         sch_tree_lock(sch);
1175         list_add_tail(&cl->hlist, &q->clhash[hfsc_hash(classid)]);
1176         list_add_tail(&cl->siblings, &parent->children);
1177         if (parent->level == 0)
1178                 hfsc_purge_queue(sch, parent);
1179         hfsc_adjust_levels(parent);
1180         sch_tree_unlock(sch);
1181
1182 #ifdef CONFIG_NET_ESTIMATOR
1183         if (tca[TCA_RATE-1])
1184                 qdisc_new_estimator(&cl->stats, tca[TCA_RATE-1]);
1185 #endif
1186         *arg = (unsigned long)cl;
1187         return 0;
1188 }
1189
1190 static void
1191 hfsc_destroy_filters(struct tcf_proto **fl)
1192 {
1193         struct tcf_proto *tp;
1194
1195         while ((tp = *fl) != NULL) {
1196                 *fl = tp->next;
1197                 tcf_destroy(tp);
1198         }
1199 }
1200
1201 static void
1202 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1203 {
1204         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1205
1206         hfsc_destroy_filters(&cl->filter_list);
1207         qdisc_destroy(cl->qdisc);
1208 #ifdef CONFIG_NET_ESTIMATOR
1209         qdisc_kill_estimator(&cl->stats);
1210 #endif
1211         if (cl != &q->root)
1212                 kfree(cl);
1213 }
1214
1215 static int
1216 hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1217 {
1218         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1219         struct hfsc_class *cl = (struct hfsc_class *)arg;
1220
1221         if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1222                 return -EBUSY;
1223
1224         sch_tree_lock(sch);
1225
1226         list_del(&cl->hlist);
1227         list_del(&cl->siblings);
1228         hfsc_adjust_levels(cl->cl_parent);
1229         hfsc_purge_queue(sch, cl);
1230         if (--cl->refcnt == 0)
1231                 hfsc_destroy_class(sch, cl);
1232
1233         sch_tree_unlock(sch);
1234         return 0;
1235 }
1236
1237 static struct hfsc_class *
1238 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch)
1239 {
1240         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1241         struct hfsc_class *cl;
1242         struct tcf_result res;
1243         struct tcf_proto *tcf;
1244         int result;
1245
1246         if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1247             (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1248                 if (cl->level == 0)
1249                         return cl;
1250
1251         tcf = q->root.filter_list;
1252         while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
1253 #ifdef CONFIG_NET_CLS_POLICE
1254                 if (result == TC_POLICE_SHOT)
1255                         return NULL;
1256 #endif
1257                 if ((cl = (struct hfsc_class *)res.class) == NULL) {
1258                         if ((cl = hfsc_find_class(res.classid, sch)) == NULL)
1259                                 break; /* filter selected invalid classid */
1260                 }
1261
1262                 if (cl->level == 0)
1263                         return cl; /* hit leaf class */
1264
1265                 /* apply inner filter chain */
1266                 tcf = cl->filter_list;
1267         }
1268
1269         /* classification failed, try default class */
1270         cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1271         if (cl == NULL || cl->level > 0)
1272                 return NULL;
1273
1274         return cl;
1275 }
1276
1277 static int
1278 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1279                  struct Qdisc **old)
1280 {
1281         struct hfsc_class *cl = (struct hfsc_class *)arg;
1282
1283         if (cl == NULL)
1284                 return -ENOENT;
1285         if (cl->level > 0)
1286                 return -EINVAL;
1287         if (new == NULL) {
1288                 new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1289                 if (new == NULL)
1290                         new = &noop_qdisc;
1291         }
1292
1293         sch_tree_lock(sch);
1294         hfsc_purge_queue(sch, cl);
1295         *old = xchg(&cl->qdisc, new);
1296         sch_tree_unlock(sch);
1297         return 0;
1298 }
1299
1300 static struct Qdisc *
1301 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1302 {
1303         struct hfsc_class *cl = (struct hfsc_class *)arg;
1304
1305         if (cl != NULL && cl->level == 0)
1306                 return cl->qdisc;
1307
1308         return NULL;
1309 }
1310
1311 static unsigned long
1312 hfsc_get_class(struct Qdisc *sch, u32 classid)
1313 {
1314         struct hfsc_class *cl = hfsc_find_class(classid, sch);
1315
1316         if (cl != NULL)
1317                 cl->refcnt++;
1318
1319         return (unsigned long)cl;
1320 }
1321
1322 static void
1323 hfsc_put_class(struct Qdisc *sch, unsigned long arg)
1324 {
1325         struct hfsc_class *cl = (struct hfsc_class *)arg;
1326
1327         if (--cl->refcnt == 0)
1328                 hfsc_destroy_class(sch, cl);
1329 }
1330
1331 static unsigned long
1332 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1333 {
1334         struct hfsc_class *p = (struct hfsc_class *)parent;
1335         struct hfsc_class *cl = hfsc_find_class(classid, sch);
1336
1337         if (cl != NULL) {
1338                 if (p != NULL && p->level <= cl->level)
1339                         return 0;
1340                 cl->filter_cnt++;
1341         }
1342
1343         return (unsigned long)cl;
1344 }
1345
1346 static void
1347 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1348 {
1349         struct hfsc_class *cl = (struct hfsc_class *)arg;
1350
1351         cl->filter_cnt--;
1352 }
1353
1354 static struct tcf_proto **
1355 hfsc_tcf_chain(struct Qdisc *sch, unsigned long arg)
1356 {
1357         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1358         struct hfsc_class *cl = (struct hfsc_class *)arg;
1359
1360         if (cl == NULL)
1361                 cl = &q->root;
1362
1363         return &cl->filter_list;
1364 }
1365
1366 static int
1367 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1368 {
1369         struct tc_service_curve tsc;
1370
1371         tsc.m1 = sm2m(sc->sm1);
1372         tsc.d  = dx2d(sc->dx);
1373         tsc.m2 = sm2m(sc->sm2);
1374         RTA_PUT(skb, attr, sizeof(tsc), &tsc);
1375
1376         return skb->len;
1377
1378  rtattr_failure:
1379         return -1;
1380 }
1381
1382 static inline int
1383 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1384 {
1385         if ((cl->cl_flags & HFSC_RSC) &&
1386             (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1387                 goto rtattr_failure;
1388
1389         if ((cl->cl_flags & HFSC_FSC) &&
1390             (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1391                 goto rtattr_failure;
1392
1393         if ((cl->cl_flags & HFSC_USC) &&
1394             (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1395                 goto rtattr_failure;
1396
1397         return skb->len;
1398
1399  rtattr_failure:
1400         return -1;
1401 }
1402
1403 static inline int
1404 hfsc_dump_stats(struct sk_buff *skb, struct hfsc_class *cl)
1405 {
1406         cl->stats.qlen = cl->qdisc->q.qlen;
1407         if (qdisc_copy_stats(skb, &cl->stats) < 0)
1408                 goto rtattr_failure;
1409
1410         return skb->len;
1411
1412  rtattr_failure:
1413         return -1;
1414 }
1415
1416 static inline int
1417 hfsc_dump_xstats(struct sk_buff *skb, struct hfsc_class *cl)
1418 {
1419         struct tc_hfsc_stats xstats;
1420
1421         xstats.level  = cl->level;
1422         xstats.period = cl->cl_vtperiod;
1423         xstats.work   = cl->cl_total;
1424         xstats.rtwork = cl->cl_cumul;
1425         RTA_PUT(skb, TCA_XSTATS, sizeof(xstats), &xstats);
1426
1427         return skb->len;
1428
1429  rtattr_failure:
1430         return -1;
1431 }
1432
1433 static int
1434 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1435                 struct tcmsg *tcm)
1436 {
1437         struct hfsc_class *cl = (struct hfsc_class *)arg;
1438         unsigned char *b = skb->tail;
1439         struct rtattr *rta = (struct rtattr *)b;
1440
1441         tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->classid : TC_H_ROOT;
1442         tcm->tcm_handle = cl->classid;
1443         if (cl->level == 0)
1444                 tcm->tcm_info = cl->qdisc->handle;
1445
1446         RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
1447         if (hfsc_dump_curves(skb, cl) < 0)
1448                 goto rtattr_failure;
1449         rta->rta_len = skb->tail - b;
1450
1451         if ((hfsc_dump_stats(skb, cl) < 0) ||
1452             (hfsc_dump_xstats(skb, cl) < 0))
1453                 goto rtattr_failure;
1454
1455         return skb->len;
1456
1457  rtattr_failure:
1458         skb_trim(skb, b - skb->data);
1459         return -1;
1460 }
1461
1462 static void
1463 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1464 {
1465         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1466         struct hfsc_class *cl;
1467         unsigned int i;
1468
1469         if (arg->stop)
1470                 return;
1471
1472         for (i = 0; i < HFSC_HSIZE; i++) {
1473                 list_for_each_entry(cl, &q->clhash[i], hlist) {
1474                         if (arg->count < arg->skip) {
1475                                 arg->count++;
1476                                 continue;
1477                         }
1478                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1479                                 arg->stop = 1;
1480                                 return;
1481                         }
1482                         arg->count++;
1483                 }
1484         }
1485 }
1486
1487 static void
1488 hfsc_watchdog(unsigned long arg)
1489 {
1490         struct Qdisc *sch = (struct Qdisc *)arg;
1491
1492         sch->flags &= ~TCQ_F_THROTTLED;
1493         netif_schedule(sch->dev);
1494 }
1495
1496 static void
1497 hfsc_schedule_watchdog(struct Qdisc *sch, u64 cur_time)
1498 {
1499         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1500         struct hfsc_class *cl;
1501         u64 next_time = 0;
1502         long delay;
1503
1504         if ((cl = ellist_get_minel(&q->eligible)) != NULL)
1505                 next_time = cl->cl_e;
1506         if (q->root.cl_cfmin != 0) {
1507                 if (next_time == 0 || next_time > q->root.cl_cfmin)
1508                         next_time = q->root.cl_cfmin;
1509         }
1510         ASSERT(next_time != 0);
1511         delay = next_time - cur_time;
1512         delay = PSCHED_US2JIFFIE(delay);
1513
1514         sch->flags |= TCQ_F_THROTTLED;
1515         mod_timer(&q->wd_timer, jiffies + delay);
1516 }
1517
1518 static int
1519 hfsc_init_qdisc(struct Qdisc *sch, struct rtattr *opt)
1520 {
1521         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1522         struct tc_hfsc_qopt *qopt;
1523         unsigned int i;
1524
1525         if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
1526                 return -EINVAL;
1527         qopt = RTA_DATA(opt);
1528
1529         memset(q, 0, sizeof(struct hfsc_sched));
1530         sch->stats.lock = &sch->dev->queue_lock;
1531
1532         q->defcls = qopt->defcls;
1533         for (i = 0; i < HFSC_HSIZE; i++)
1534                 INIT_LIST_HEAD(&q->clhash[i]);
1535         INIT_LIST_HEAD(&q->eligible);
1536         INIT_LIST_HEAD(&q->droplist);
1537         skb_queue_head_init(&q->requeue);
1538
1539         q->root.refcnt  = 1;
1540         q->root.classid = sch->handle;
1541         q->root.sched   = q;
1542         q->root.qdisc = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops);
1543         if (q->root.qdisc == NULL)
1544                 q->root.qdisc = &noop_qdisc;
1545         q->root.stats.lock = &sch->dev->queue_lock;
1546         INIT_LIST_HEAD(&q->root.children);
1547         INIT_LIST_HEAD(&q->root.actlist);
1548
1549         list_add(&q->root.hlist, &q->clhash[hfsc_hash(q->root.classid)]);
1550
1551         init_timer(&q->wd_timer);
1552         q->wd_timer.function = hfsc_watchdog;
1553         q->wd_timer.data = (unsigned long)sch;
1554
1555         return 0;
1556 }
1557
1558 static int
1559 hfsc_change_qdisc(struct Qdisc *sch, struct rtattr *opt)
1560 {
1561         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1562         struct tc_hfsc_qopt *qopt;
1563
1564         if (opt == NULL || RTA_PAYLOAD(opt) < sizeof(*qopt))
1565                 return -EINVAL;
1566         qopt = RTA_DATA(opt);
1567
1568         sch_tree_lock(sch);
1569         q->defcls = qopt->defcls;
1570         sch_tree_unlock(sch);
1571
1572         return 0;
1573 }
1574
1575 static void
1576 hfsc_reset_class(struct hfsc_class *cl)
1577 {
1578         cl->cl_total        = 0;
1579         cl->cl_cumul        = 0;
1580         cl->cl_d            = 0;
1581         cl->cl_e            = 0;
1582         cl->cl_vt           = 0;
1583         cl->cl_vtadj        = 0;
1584         cl->cl_vtoff        = 0;
1585         cl->cl_cvtmin       = 0;
1586         cl->cl_cvtmax       = 0;
1587         cl->cl_vtperiod     = 0;
1588         cl->cl_parentperiod = 0;
1589         cl->cl_f            = 0;
1590         cl->cl_myf          = 0;
1591         cl->cl_myfadj       = 0;
1592         cl->cl_cfmin        = 0;
1593         cl->cl_nactive      = 0;
1594         INIT_LIST_HEAD(&cl->actlist);
1595         qdisc_reset(cl->qdisc);
1596
1597         if (cl->cl_flags & HFSC_RSC)
1598                 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1599         if (cl->cl_flags & HFSC_FSC)
1600                 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1601         if (cl->cl_flags & HFSC_USC)
1602                 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1603 }
1604
1605 static void
1606 hfsc_reset_qdisc(struct Qdisc *sch)
1607 {
1608         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1609         struct hfsc_class *cl;
1610         unsigned int i;
1611
1612         for (i = 0; i < HFSC_HSIZE; i++) {
1613                 list_for_each_entry(cl, &q->clhash[i], hlist)
1614                         hfsc_reset_class(cl);
1615         }
1616         __skb_queue_purge(&q->requeue);
1617         INIT_LIST_HEAD(&q->eligible);
1618         INIT_LIST_HEAD(&q->droplist);
1619         del_timer(&q->wd_timer);
1620         sch->flags &= ~TCQ_F_THROTTLED;
1621         sch->q.qlen = 0;
1622 }
1623
1624 static void
1625 hfsc_destroy_qdisc(struct Qdisc *sch)
1626 {
1627         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1628         struct hfsc_class *cl, *next;
1629         unsigned int i;
1630
1631         for (i = 0; i < HFSC_HSIZE; i++) {
1632                 list_for_each_entry_safe(cl, next, &q->clhash[i], hlist)
1633                         hfsc_destroy_class(sch, cl);
1634         }
1635         __skb_queue_purge(&q->requeue);
1636         del_timer(&q->wd_timer);
1637 }
1638
1639 static int
1640 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1641 {
1642         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1643         unsigned char *b = skb->tail;
1644         struct tc_hfsc_qopt qopt;
1645
1646         qopt.defcls = q->defcls;
1647         RTA_PUT(skb, TCA_OPTIONS, sizeof(qopt), &qopt);
1648
1649         sch->stats.qlen = sch->q.qlen;
1650         if (qdisc_copy_stats(skb, &sch->stats) < 0)
1651                 goto rtattr_failure;
1652
1653         return skb->len;
1654
1655  rtattr_failure:
1656         skb_trim(skb, b - skb->data);
1657         return -1;
1658 }
1659
1660 static int
1661 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
1662 {
1663         struct hfsc_class *cl = hfsc_classify(skb, sch);
1664         unsigned int len = skb->len;
1665         int err;
1666
1667         if (cl == NULL) {
1668                 kfree_skb(skb);
1669                 sch->stats.drops++;
1670                 return NET_XMIT_DROP;
1671         }
1672
1673         err = cl->qdisc->enqueue(skb, cl->qdisc);
1674         if (unlikely(err != NET_XMIT_SUCCESS)) {
1675                 cl->stats.drops++;
1676                 sch->stats.drops++;
1677                 return err;
1678         }
1679
1680         if (cl->qdisc->q.qlen == 1)
1681                 set_active(cl, len);
1682
1683         cl->stats.packets++;
1684         cl->stats.bytes += len;
1685         sch->stats.packets++;
1686         sch->stats.bytes += len;
1687         sch->q.qlen++;
1688
1689         return NET_XMIT_SUCCESS;
1690 }
1691
1692 static struct sk_buff *
1693 hfsc_dequeue(struct Qdisc *sch)
1694 {
1695         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1696         struct hfsc_class *cl;
1697         struct sk_buff *skb;
1698         u64 cur_time;
1699         unsigned int next_len;
1700         int realtime = 0;
1701
1702         if (sch->q.qlen == 0)
1703                 return NULL;
1704         if ((skb = __skb_dequeue(&q->requeue)))
1705                 goto out;
1706
1707         PSCHED_GET_TIME(cur_time);
1708
1709         /*
1710          * if there are eligible classes, use real-time criteria.
1711          * find the class with the minimum deadline among
1712          * the eligible classes.
1713          */
1714         if ((cl = ellist_get_mindl(&q->eligible, cur_time)) != NULL) {
1715                 realtime = 1;
1716         } else {
1717                 /*
1718                  * use link-sharing criteria
1719                  * get the class with the minimum vt in the hierarchy
1720                  */
1721                 cl = actlist_get_minvt(&q->root, cur_time);
1722                 if (cl == NULL) {
1723                         sch->stats.overlimits++;
1724                         if (!netif_queue_stopped(sch->dev))
1725                                 hfsc_schedule_watchdog(sch, cur_time);
1726                         return NULL;
1727                 }
1728         }
1729
1730         skb = cl->qdisc->dequeue(cl->qdisc);
1731         if (skb == NULL) {
1732                 if (net_ratelimit())
1733                         printk("HFSC: Non-work-conserving qdisc ?\n");
1734                 return NULL;
1735         }
1736
1737         update_vf(cl, skb->len, cur_time);
1738         if (realtime)
1739                 cl->cl_cumul += skb->len;
1740
1741         if (cl->qdisc->q.qlen != 0) {
1742                 if (cl->cl_flags & HFSC_RSC) {
1743                         /* update ed */
1744                         next_len = qdisc_peek_len(cl->qdisc);
1745                         if (realtime)
1746                                 update_ed(cl, next_len);
1747                         else
1748                                 update_d(cl, next_len);
1749                 }
1750         } else {
1751                 /* the class becomes passive */
1752                 set_passive(cl);
1753         }
1754
1755  out:
1756         sch->flags &= ~TCQ_F_THROTTLED;
1757         sch->q.qlen--;
1758
1759         return skb;
1760 }
1761
1762 static int
1763 hfsc_requeue(struct sk_buff *skb, struct Qdisc *sch)
1764 {
1765         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1766
1767         __skb_queue_head(&q->requeue, skb);
1768         sch->q.qlen++;
1769         return NET_XMIT_SUCCESS;
1770 }
1771
1772 static unsigned int
1773 hfsc_drop(struct Qdisc *sch)
1774 {
1775         struct hfsc_sched *q = (struct hfsc_sched *)sch->data;
1776         struct hfsc_class *cl;
1777         unsigned int len;
1778
1779         list_for_each_entry(cl, &q->droplist, dlist) {
1780                 if (cl->qdisc->ops->drop != NULL &&
1781                     (len = cl->qdisc->ops->drop(cl->qdisc)) > 0) {
1782                         if (cl->qdisc->q.qlen == 0) {
1783                                 update_vf(cl, 0, 0);
1784                                 set_passive(cl);
1785                         } else {
1786                                 list_move_tail(&cl->dlist, &q->droplist);
1787                         }
1788                         cl->stats.drops++;
1789                         sch->stats.drops++;
1790                         sch->q.qlen--;
1791                         return len;
1792                 }
1793         }
1794         return 0;
1795 }
1796
1797 static struct Qdisc_class_ops hfsc_class_ops = {
1798         .change         = hfsc_change_class,
1799         .delete         = hfsc_delete_class,
1800         .graft          = hfsc_graft_class,
1801         .leaf           = hfsc_class_leaf,
1802         .get            = hfsc_get_class,
1803         .put            = hfsc_put_class,
1804         .bind_tcf       = hfsc_bind_tcf,
1805         .unbind_tcf     = hfsc_unbind_tcf,
1806         .tcf_chain      = hfsc_tcf_chain,
1807         .dump           = hfsc_dump_class,
1808         .walk           = hfsc_walk
1809 };
1810
1811 static struct Qdisc_ops hfsc_qdisc_ops = {
1812         .id             = "hfsc",
1813         .init           = hfsc_init_qdisc,
1814         .change         = hfsc_change_qdisc,
1815         .reset          = hfsc_reset_qdisc,
1816         .destroy        = hfsc_destroy_qdisc,
1817         .dump           = hfsc_dump_qdisc,
1818         .enqueue        = hfsc_enqueue,
1819         .dequeue        = hfsc_dequeue,
1820         .requeue        = hfsc_requeue,
1821         .drop           = hfsc_drop,
1822         .cl_ops         = &hfsc_class_ops,
1823         .priv_size      = sizeof(struct hfsc_sched),
1824         .owner          = THIS_MODULE
1825 };
1826
1827 static int __init
1828 hfsc_init(void)
1829 {
1830         return register_qdisc(&hfsc_qdisc_ops);
1831 }
1832
1833 static void __exit
1834 hfsc_cleanup(void)
1835 {
1836         unregister_qdisc(&hfsc_qdisc_ops);
1837 }
1838
1839 MODULE_LICENSE("GPL");
1840 module_init(hfsc_init);
1841 module_exit(hfsc_cleanup);