net/sched/sch

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This source file includes following definitions.
eltree_insert
eltree_remove
eltree_update
eltree_get_mindl
eltree_get_minel
vttree_insert
vttree_remove
vttree_update
vttree_firstfit
vttree_get_minvt
cftree_insert
cftree_remove
cftree_update
seg_x2y
seg_y2x
m2sm
m2ism
d2dx
sm2m
dx2d
sc2isc
rtsc_init
rtsc_y2x
rtsc_x2y
rtsc_min
init_ed
update_ed
update_d
update_cfmin
init_vf
update_vf
qdisc_peek_len
hfsc_adjust_levels
hfsc_find_class
hfsc_change_rsc
hfsc_change_fsc
hfsc_change_usc
hfsc_change_class
hfsc_destroy_class
hfsc_delete_class
hfsc_classify
hfsc_graft_class
hfsc_class_leaf
hfsc_qlen_notify
hfsc_search_class
hfsc_bind_tcf
hfsc_unbind_tcf
hfsc_tcf_block
hfsc_dump_sc
hfsc_dump_curves
hfsc_dump_class
hfsc_dump_class_stats
hfsc_walk
hfsc_schedule_watchdog
hfsc_init_qdisc
hfsc_change_qdisc
hfsc_reset_class
hfsc_reset_qdisc
hfsc_destroy_qdisc
hfsc_dump_qdisc
hfsc_enqueue
hfsc_dequeue
hfsc_init
hfsc_cleanup
   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 
  84 struct 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 */
  94 struct 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 
 105 enum hfsc_class_flags {
 106         HFSC_RSC = 0x1,
 107         HFSC_FSC = 0x2,
 108         HFSC_USC = 0x4
 109 };
 110 
 111 struct hfsc_class {
 112         struct Qdisc_class_common cl_common;
 113 
 114         struct gnet_stats_basic_packed bstats;
 115         struct gnet_stats_queue qstats;
 116         struct net_rate_estimator __rcu *rate_est;
 117         struct tcf_proto __rcu *filter_list; /* filter list */
 118         struct tcf_block *block;
 119         unsigned int    filter_cnt;     /* filter count */
 120         unsigned int    level;          /* class level in hierarchy */
 121 
 122         struct hfsc_sched *sched;       /* scheduler data */
 123         struct hfsc_class *cl_parent;   /* parent class */
 124         struct list_head siblings;      /* sibling classes */
 125         struct list_head children;      /* child classes */
 126         struct Qdisc    *qdisc;         /* leaf qdisc */
 127 
 128         struct rb_node el_node;         /* qdisc's eligible tree member */
 129         struct rb_root vt_tree;         /* active children sorted by cl_vt */
 130         struct rb_node vt_node;         /* parent's vt_tree member */
 131         struct rb_root cf_tree;         /* active children sorted by cl_f */
 132         struct rb_node cf_node;         /* parent's cf_heap member */
 133 
 134         u64     cl_total;               /* total work in bytes */
 135         u64     cl_cumul;               /* cumulative work in bytes done by
 136                                            real-time criteria */
 137 
 138         u64     cl_d;                   /* deadline*/
 139         u64     cl_e;                   /* eligible time */
 140         u64     cl_vt;                  /* virtual time */
 141         u64     cl_f;                   /* time when this class will fit for
 142                                            link-sharing, max(myf, cfmin) */
 143         u64     cl_myf;                 /* my fit-time (calculated from this
 144                                            class's own upperlimit curve) */
 145         u64     cl_cfmin;               /* earliest children's fit-time (used
 146                                            with cl_myf to obtain cl_f) */
 147         u64     cl_cvtmin;              /* minimal virtual time among the
 148                                            children fit for link-sharing
 149                                            (monotonic within a period) */
 150         u64     cl_vtadj;               /* intra-period cumulative vt
 151                                            adjustment */
 152         u64     cl_cvtoff;              /* largest virtual time seen among
 153                                            the children */
 154 
 155         struct internal_sc cl_rsc;      /* internal real-time service curve */
 156         struct internal_sc cl_fsc;      /* internal fair service curve */
 157         struct internal_sc cl_usc;      /* internal upperlimit service curve */
 158         struct runtime_sc cl_deadline;  /* deadline curve */
 159         struct runtime_sc cl_eligible;  /* eligible curve */
 160         struct runtime_sc cl_virtual;   /* virtual curve */
 161         struct runtime_sc cl_ulimit;    /* upperlimit curve */
 162 
 163         u8              cl_flags;       /* which curves are valid */
 164         u32             cl_vtperiod;    /* vt period sequence number */
 165         u32             cl_parentperiod;/* parent's vt period sequence number*/
 166         u32             cl_nactive;     /* number of active children */
 167 };
 168 
 169 struct hfsc_sched {
 170         u16     defcls;                         /* default class id */
 171         struct hfsc_class root;                 /* root class */
 172         struct Qdisc_class_hash clhash;         /* class hash */
 173         struct rb_root eligible;                /* eligible tree */
 174         struct qdisc_watchdog watchdog;         /* watchdog timer */
 175 };
 176 
 177 #define HT_INFINITY     0xffffffffffffffffULL   /* infinite time value */
 178 
 179 
 180 /*
 181  * eligible tree holds backlogged classes being sorted by their eligible times.
 182  * there is one eligible tree per hfsc instance.
 183  */
 184 
 185 static void
 186 eltree_insert(struct hfsc_class *cl)
 187 {
 188         struct rb_node **p = &cl->sched->eligible.rb_node;
 189         struct rb_node *parent = NULL;
 190         struct hfsc_class *cl1;
 191 
 192         while (*p != NULL) {
 193                 parent = *p;
 194                 cl1 = rb_entry(parent, struct hfsc_class, el_node);
 195                 if (cl->cl_e >= cl1->cl_e)
 196                         p = &parent->rb_right;
 197                 else
 198                         p = &parent->rb_left;
 199         }
 200         rb_link_node(&cl->el_node, parent, p);
 201         rb_insert_color(&cl->el_node, &cl->sched->eligible);
 202 }
 203 
 204 static inline void
 205 eltree_remove(struct hfsc_class *cl)
 206 {
 207         rb_erase(&cl->el_node, &cl->sched->eligible);
 208 }
 209 
 210 static inline void
 211 eltree_update(struct hfsc_class *cl)
 212 {
 213         eltree_remove(cl);
 214         eltree_insert(cl);
 215 }
 216 
 217 /* find the class with the minimum deadline among the eligible classes */
 218 static inline struct hfsc_class *
 219 eltree_get_mindl(struct hfsc_sched *q, u64 cur_time)
 220 {
 221         struct hfsc_class *p, *cl = NULL;
 222         struct rb_node *n;
 223 
 224         for (n = rb_first(&q->eligible); n != NULL; n = rb_next(n)) {
 225                 p = rb_entry(n, struct hfsc_class, el_node);
 226                 if (p->cl_e > cur_time)
 227                         break;
 228                 if (cl == NULL || p->cl_d < cl->cl_d)
 229                         cl = p;
 230         }
 231         return cl;
 232 }
 233 
 234 /* find the class with minimum eligible time among the eligible classes */
 235 static inline struct hfsc_class *
 236 eltree_get_minel(struct hfsc_sched *q)
 237 {
 238         struct rb_node *n;
 239 
 240         n = rb_first(&q->eligible);
 241         if (n == NULL)
 242                 return NULL;
 243         return rb_entry(n, struct hfsc_class, el_node);
 244 }
 245 
 246 /*
 247  * vttree holds holds backlogged child classes being sorted by their virtual
 248  * time. each intermediate class has one vttree.
 249  */
 250 static void
 251 vttree_insert(struct hfsc_class *cl)
 252 {
 253         struct rb_node **p = &cl->cl_parent->vt_tree.rb_node;
 254         struct rb_node *parent = NULL;
 255         struct hfsc_class *cl1;
 256 
 257         while (*p != NULL) {
 258                 parent = *p;
 259                 cl1 = rb_entry(parent, struct hfsc_class, vt_node);
 260                 if (cl->cl_vt >= cl1->cl_vt)
 261                         p = &parent->rb_right;
 262                 else
 263                         p = &parent->rb_left;
 264         }
 265         rb_link_node(&cl->vt_node, parent, p);
 266         rb_insert_color(&cl->vt_node, &cl->cl_parent->vt_tree);
 267 }
 268 
 269 static inline void
 270 vttree_remove(struct hfsc_class *cl)
 271 {
 272         rb_erase(&cl->vt_node, &cl->cl_parent->vt_tree);
 273 }
 274 
 275 static inline void
 276 vttree_update(struct hfsc_class *cl)
 277 {
 278         vttree_remove(cl);
 279         vttree_insert(cl);
 280 }
 281 
 282 static inline struct hfsc_class *
 283 vttree_firstfit(struct hfsc_class *cl, u64 cur_time)
 284 {
 285         struct hfsc_class *p;
 286         struct rb_node *n;
 287 
 288         for (n = rb_first(&cl->vt_tree); n != NULL; n = rb_next(n)) {
 289                 p = rb_entry(n, struct hfsc_class, vt_node);
 290                 if (p->cl_f <= cur_time)
 291                         return p;
 292         }
 293         return NULL;
 294 }
 295 
 296 /*
 297  * get the leaf class with the minimum vt in the hierarchy
 298  */
 299 static struct hfsc_class *
 300 vttree_get_minvt(struct hfsc_class *cl, u64 cur_time)
 301 {
 302         /* if root-class's cfmin is bigger than cur_time nothing to do */
 303         if (cl->cl_cfmin > cur_time)
 304                 return NULL;
 305 
 306         while (cl->level > 0) {
 307                 cl = vttree_firstfit(cl, cur_time);
 308                 if (cl == NULL)
 309                         return NULL;
 310                 /*
 311                  * update parent's cl_cvtmin.
 312                  */
 313                 if (cl->cl_parent->cl_cvtmin < cl->cl_vt)
 314                         cl->cl_parent->cl_cvtmin = cl->cl_vt;
 315         }
 316         return cl;
 317 }
 318 
 319 static void
 320 cftree_insert(struct hfsc_class *cl)
 321 {
 322         struct rb_node **p = &cl->cl_parent->cf_tree.rb_node;
 323         struct rb_node *parent = NULL;
 324         struct hfsc_class *cl1;
 325 
 326         while (*p != NULL) {
 327                 parent = *p;
 328                 cl1 = rb_entry(parent, struct hfsc_class, cf_node);
 329                 if (cl->cl_f >= cl1->cl_f)
 330                         p = &parent->rb_right;
 331                 else
 332                         p = &parent->rb_left;
 333         }
 334         rb_link_node(&cl->cf_node, parent, p);
 335         rb_insert_color(&cl->cf_node, &cl->cl_parent->cf_tree);
 336 }
 337 
 338 static inline void
 339 cftree_remove(struct hfsc_class *cl)
 340 {
 341         rb_erase(&cl->cf_node, &cl->cl_parent->cf_tree);
 342 }
 343 
 344 static inline void
 345 cftree_update(struct hfsc_class *cl)
 346 {
 347         cftree_remove(cl);
 348         cftree_insert(cl);
 349 }
 350 
 351 /*
 352  * service curve support functions
 353  *
 354  *  external service curve parameters
 355  *      m: bps
 356  *      d: us
 357  *  internal service curve parameters
 358  *      sm: (bytes/psched_us) << SM_SHIFT
 359  *      ism: (psched_us/byte) << ISM_SHIFT
 360  *      dx: psched_us
 361  *
 362  * The clock source resolution with ktime and PSCHED_SHIFT 10 is 1.024us.
 363  *
 364  * sm and ism are scaled in order to keep effective digits.
 365  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
 366  * digits in decimal using the following table.
 367  *
 368  *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
 369  *  ------------+-------------------------------------------------------
 370  *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
 371  *
 372  *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
 373  *
 374  * So, for PSCHED_SHIFT 10 we need: SM_SHIFT 20, ISM_SHIFT 18.
 375  */
 376 #define SM_SHIFT        (30 - PSCHED_SHIFT)
 377 #define ISM_SHIFT       (8 + PSCHED_SHIFT)
 378 
 379 #define SM_MASK         ((1ULL << SM_SHIFT) - 1)
 380 #define ISM_MASK        ((1ULL << ISM_SHIFT) - 1)
 381 
 382 static inline u64
 383 seg_x2y(u64 x, u64 sm)
 384 {
 385         u64 y;
 386 
 387         /*
 388          * compute
 389          *      y = x * sm >> SM_SHIFT
 390          * but divide it for the upper and lower bits to avoid overflow
 391          */
 392         y = (x >> SM_SHIFT) * sm + (((x & SM_MASK) * sm) >> SM_SHIFT);
 393         return y;
 394 }
 395 
 396 static inline u64
 397 seg_y2x(u64 y, u64 ism)
 398 {
 399         u64 x;
 400 
 401         if (y == 0)
 402                 x = 0;
 403         else if (ism == HT_INFINITY)
 404                 x = HT_INFINITY;
 405         else {
 406                 x = (y >> ISM_SHIFT) * ism
 407                     + (((y & ISM_MASK) * ism) >> ISM_SHIFT);
 408         }
 409         return x;
 410 }
 411 
 412 /* Convert m (bps) into sm (bytes/psched us) */
 413 static u64
 414 m2sm(u32 m)
 415 {
 416         u64 sm;
 417 
 418         sm = ((u64)m << SM_SHIFT);
 419         sm += PSCHED_TICKS_PER_SEC - 1;
 420         do_div(sm, PSCHED_TICKS_PER_SEC);
 421         return sm;
 422 }
 423 
 424 /* convert m (bps) into ism (psched us/byte) */
 425 static u64
 426 m2ism(u32 m)
 427 {
 428         u64 ism;
 429 
 430         if (m == 0)
 431                 ism = HT_INFINITY;
 432         else {
 433                 ism = ((u64)PSCHED_TICKS_PER_SEC << ISM_SHIFT);
 434                 ism += m - 1;
 435                 do_div(ism, m);
 436         }
 437         return ism;
 438 }
 439 
 440 /* convert d (us) into dx (psched us) */
 441 static u64
 442 d2dx(u32 d)
 443 {
 444         u64 dx;
 445 
 446         dx = ((u64)d * PSCHED_TICKS_PER_SEC);
 447         dx += USEC_PER_SEC - 1;
 448         do_div(dx, USEC_PER_SEC);
 449         return dx;
 450 }
 451 
 452 /* convert sm (bytes/psched us) into m (bps) */
 453 static u32
 454 sm2m(u64 sm)
 455 {
 456         u64 m;
 457 
 458         m = (sm * PSCHED_TICKS_PER_SEC) >> SM_SHIFT;
 459         return (u32)m;
 460 }
 461 
 462 /* convert dx (psched us) into d (us) */
 463 static u32
 464 dx2d(u64 dx)
 465 {
 466         u64 d;
 467 
 468         d = dx * USEC_PER_SEC;
 469         do_div(d, PSCHED_TICKS_PER_SEC);
 470         return (u32)d;
 471 }
 472 
 473 static void
 474 sc2isc(struct tc_service_curve *sc, struct internal_sc *isc)
 475 {
 476         isc->sm1  = m2sm(sc->m1);
 477         isc->ism1 = m2ism(sc->m1);
 478         isc->dx   = d2dx(sc->d);
 479         isc->dy   = seg_x2y(isc->dx, isc->sm1);
 480         isc->sm2  = m2sm(sc->m2);
 481         isc->ism2 = m2ism(sc->m2);
 482 }
 483 
 484 /*
 485  * initialize the runtime service curve with the given internal
 486  * service curve starting at (x, y).
 487  */
 488 static void
 489 rtsc_init(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 490 {
 491         rtsc->x    = x;
 492         rtsc->y    = y;
 493         rtsc->sm1  = isc->sm1;
 494         rtsc->ism1 = isc->ism1;
 495         rtsc->dx   = isc->dx;
 496         rtsc->dy   = isc->dy;
 497         rtsc->sm2  = isc->sm2;
 498         rtsc->ism2 = isc->ism2;
 499 }
 500 
 501 /*
 502  * calculate the y-projection of the runtime service curve by the
 503  * given x-projection value
 504  */
 505 static u64
 506 rtsc_y2x(struct runtime_sc *rtsc, u64 y)
 507 {
 508         u64 x;
 509 
 510         if (y < rtsc->y)
 511                 x = rtsc->x;
 512         else if (y <= rtsc->y + rtsc->dy) {
 513                 /* x belongs to the 1st segment */
 514                 if (rtsc->dy == 0)
 515                         x = rtsc->x + rtsc->dx;
 516                 else
 517                         x = rtsc->x + seg_y2x(y - rtsc->y, rtsc->ism1);
 518         } else {
 519                 /* x belongs to the 2nd segment */
 520                 x = rtsc->x + rtsc->dx
 521                     + seg_y2x(y - rtsc->y - rtsc->dy, rtsc->ism2);
 522         }
 523         return x;
 524 }
 525 
 526 static u64
 527 rtsc_x2y(struct runtime_sc *rtsc, u64 x)
 528 {
 529         u64 y;
 530 
 531         if (x <= rtsc->x)
 532                 y = rtsc->y;
 533         else if (x <= rtsc->x + rtsc->dx)
 534                 /* y belongs to the 1st segment */
 535                 y = rtsc->y + seg_x2y(x - rtsc->x, rtsc->sm1);
 536         else
 537                 /* y belongs to the 2nd segment */
 538                 y = rtsc->y + rtsc->dy
 539                     + seg_x2y(x - rtsc->x - rtsc->dx, rtsc->sm2);
 540         return y;
 541 }
 542 
 543 /*
 544  * update the runtime service curve by taking the minimum of the current
 545  * runtime service curve and the service curve starting at (x, y).
 546  */
 547 static void
 548 rtsc_min(struct runtime_sc *rtsc, struct internal_sc *isc, u64 x, u64 y)
 549 {
 550         u64 y1, y2, dx, dy;
 551         u32 dsm;
 552 
 553         if (isc->sm1 <= isc->sm2) {
 554                 /* service curve is convex */
 555                 y1 = rtsc_x2y(rtsc, x);
 556                 if (y1 < y)
 557                         /* the current rtsc is smaller */
 558                         return;
 559                 rtsc->x = x;
 560                 rtsc->y = y;
 561                 return;
 562         }
 563 
 564         /*
 565          * service curve is concave
 566          * compute the two y values of the current rtsc
 567          *      y1: at x
 568          *      y2: at (x + dx)
 569          */
 570         y1 = rtsc_x2y(rtsc, x);
 571         if (y1 <= y) {
 572                 /* rtsc is below isc, no change to rtsc */
 573                 return;
 574         }
 575 
 576         y2 = rtsc_x2y(rtsc, x + isc->dx);
 577         if (y2 >= y + isc->dy) {
 578                 /* rtsc is above isc, replace rtsc by isc */
 579                 rtsc->x = x;
 580                 rtsc->y = y;
 581                 rtsc->dx = isc->dx;
 582                 rtsc->dy = isc->dy;
 583                 return;
 584         }
 585 
 586         /*
 587          * the two curves intersect
 588          * compute the offsets (dx, dy) using the reverse
 589          * function of seg_x2y()
 590          *      seg_x2y(dx, sm1) == seg_x2y(dx, sm2) + (y1 - y)
 591          */
 592         dx = (y1 - y) << SM_SHIFT;
 593         dsm = isc->sm1 - isc->sm2;
 594         do_div(dx, dsm);
 595         /*
 596          * check if (x, y1) belongs to the 1st segment of rtsc.
 597          * if so, add the offset.
 598          */
 599         if (rtsc->x + rtsc->dx > x)
 600                 dx += rtsc->x + rtsc->dx - x;
 601         dy = seg_x2y(dx, isc->sm1);
 602 
 603         rtsc->x = x;
 604         rtsc->y = y;
 605         rtsc->dx = dx;
 606         rtsc->dy = dy;
 607 }
 608 
 609 static void
 610 init_ed(struct hfsc_class *cl, unsigned int next_len)
 611 {
 612         u64 cur_time = psched_get_time();
 613 
 614         /* update the deadline curve */
 615         rtsc_min(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
 616 
 617         /*
 618          * update the eligible curve.
 619          * for concave, it is equal to the deadline curve.
 620          * for convex, it is a linear curve with slope m2.
 621          */
 622         cl->cl_eligible = cl->cl_deadline;
 623         if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
 624                 cl->cl_eligible.dx = 0;
 625                 cl->cl_eligible.dy = 0;
 626         }
 627 
 628         /* compute e and d */
 629         cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
 630         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 631 
 632         eltree_insert(cl);
 633 }
 634 
 635 static void
 636 update_ed(struct hfsc_class *cl, unsigned int next_len)
 637 {
 638         cl->cl_e = rtsc_y2x(&cl->cl_eligible, cl->cl_cumul);
 639         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 640 
 641         eltree_update(cl);
 642 }
 643 
 644 static inline void
 645 update_d(struct hfsc_class *cl, unsigned int next_len)
 646 {
 647         cl->cl_d = rtsc_y2x(&cl->cl_deadline, cl->cl_cumul + next_len);
 648 }
 649 
 650 static inline void
 651 update_cfmin(struct hfsc_class *cl)
 652 {
 653         struct rb_node *n = rb_first(&cl->cf_tree);
 654         struct hfsc_class *p;
 655 
 656         if (n == NULL) {
 657                 cl->cl_cfmin = 0;
 658                 return;
 659         }
 660         p = rb_entry(n, struct hfsc_class, cf_node);
 661         cl->cl_cfmin = p->cl_f;
 662 }
 663 
 664 static void
 665 init_vf(struct hfsc_class *cl, unsigned int len)
 666 {
 667         struct hfsc_class *max_cl;
 668         struct rb_node *n;
 669         u64 vt, f, cur_time;
 670         int go_active;
 671 
 672         cur_time = 0;
 673         go_active = 1;
 674         for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
 675                 if (go_active && cl->cl_nactive++ == 0)
 676                         go_active = 1;
 677                 else
 678                         go_active = 0;
 679 
 680                 if (go_active) {
 681                         n = rb_last(&cl->cl_parent->vt_tree);
 682                         if (n != NULL) {
 683                                 max_cl = rb_entry(n, struct hfsc_class, vt_node);
 684                                 /*
 685                                  * set vt to the average of the min and max
 686                                  * classes.  if the parent's period didn't
 687                                  * change, don't decrease vt of the class.
 688                                  */
 689                                 vt = max_cl->cl_vt;
 690                                 if (cl->cl_parent->cl_cvtmin != 0)
 691                                         vt = (cl->cl_parent->cl_cvtmin + vt)/2;
 692 
 693                                 if (cl->cl_parent->cl_vtperiod !=
 694                                     cl->cl_parentperiod || vt > cl->cl_vt)
 695                                         cl->cl_vt = vt;
 696                         } else {
 697                                 /*
 698                                  * first child for a new parent backlog period.
 699                                  * initialize cl_vt to the highest value seen
 700                                  * among the siblings. this is analogous to
 701                                  * what cur_time would provide in realtime case.
 702                                  */
 703                                 cl->cl_vt = cl->cl_parent->cl_cvtoff;
 704                                 cl->cl_parent->cl_cvtmin = 0;
 705                         }
 706 
 707                         /* update the virtual curve */
 708                         rtsc_min(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
 709                         cl->cl_vtadj = 0;
 710 
 711                         cl->cl_vtperiod++;  /* increment vt period */
 712                         cl->cl_parentperiod = cl->cl_parent->cl_vtperiod;
 713                         if (cl->cl_parent->cl_nactive == 0)
 714                                 cl->cl_parentperiod++;
 715                         cl->cl_f = 0;
 716 
 717                         vttree_insert(cl);
 718                         cftree_insert(cl);
 719 
 720                         if (cl->cl_flags & HFSC_USC) {
 721                                 /* class has upper limit curve */
 722                                 if (cur_time == 0)
 723                                         cur_time = psched_get_time();
 724 
 725                                 /* update the ulimit curve */
 726                                 rtsc_min(&cl->cl_ulimit, &cl->cl_usc, cur_time,
 727                                          cl->cl_total);
 728                                 /* compute myf */
 729                                 cl->cl_myf = rtsc_y2x(&cl->cl_ulimit,
 730                                                       cl->cl_total);
 731                         }
 732                 }
 733 
 734                 f = max(cl->cl_myf, cl->cl_cfmin);
 735                 if (f != cl->cl_f) {
 736                         cl->cl_f = f;
 737                         cftree_update(cl);
 738                 }
 739                 update_cfmin(cl->cl_parent);
 740         }
 741 }
 742 
 743 static void
 744 update_vf(struct hfsc_class *cl, unsigned int len, u64 cur_time)
 745 {
 746         u64 f; /* , myf_bound, delta; */
 747         int go_passive = 0;
 748 
 749         if (cl->qdisc->q.qlen == 0 && cl->cl_flags & HFSC_FSC)
 750                 go_passive = 1;
 751 
 752         for (; cl->cl_parent != NULL; cl = cl->cl_parent) {
 753                 cl->cl_total += len;
 754 
 755                 if (!(cl->cl_flags & HFSC_FSC) || cl->cl_nactive == 0)
 756                         continue;
 757 
 758                 if (go_passive && --cl->cl_nactive == 0)
 759                         go_passive = 1;
 760                 else
 761                         go_passive = 0;
 762 
 763                 /* update vt */
 764                 cl->cl_vt = rtsc_y2x(&cl->cl_virtual, cl->cl_total) + cl->cl_vtadj;
 765 
 766                 /*
 767                  * if vt of the class is smaller than cvtmin,
 768                  * the class was skipped in the past due to non-fit.
 769                  * if so, we need to adjust vtadj.
 770                  */
 771                 if (cl->cl_vt < cl->cl_parent->cl_cvtmin) {
 772                         cl->cl_vtadj += cl->cl_parent->cl_cvtmin - cl->cl_vt;
 773                         cl->cl_vt = cl->cl_parent->cl_cvtmin;
 774                 }
 775 
 776                 if (go_passive) {
 777                         /* no more active child, going passive */
 778 
 779                         /* update cvtoff of the parent class */
 780                         if (cl->cl_vt > cl->cl_parent->cl_cvtoff)
 781                                 cl->cl_parent->cl_cvtoff = cl->cl_vt;
 782 
 783                         /* remove this class from the vt tree */
 784                         vttree_remove(cl);
 785 
 786                         cftree_remove(cl);
 787                         update_cfmin(cl->cl_parent);
 788 
 789                         continue;
 790                 }
 791 
 792                 /* update the vt tree */
 793                 vttree_update(cl);
 794 
 795                 /* update f */
 796                 if (cl->cl_flags & HFSC_USC) {
 797                         cl->cl_myf = rtsc_y2x(&cl->cl_ulimit, cl->cl_total);
 798 #if 0
 799                         cl->cl_myf = cl->cl_myfadj + rtsc_y2x(&cl->cl_ulimit,
 800                                                               cl->cl_total);
 801                         /*
 802                          * This code causes classes to stay way under their
 803                          * limit when multiple classes are used at gigabit
 804                          * speed. needs investigation. -kaber
 805                          */
 806                         /*
 807                          * if myf lags behind by more than one clock tick
 808                          * from the current time, adjust myfadj to prevent
 809                          * a rate-limited class from going greedy.
 810                          * in a steady state under rate-limiting, myf
 811                          * fluctuates within one clock tick.
 812                          */
 813                         myf_bound = cur_time - PSCHED_JIFFIE2US(1);
 814                         if (cl->cl_myf < myf_bound) {
 815                                 delta = cur_time - cl->cl_myf;
 816                                 cl->cl_myfadj += delta;
 817                                 cl->cl_myf += delta;
 818                         }
 819 #endif
 820                 }
 821 
 822                 f = max(cl->cl_myf, cl->cl_cfmin);
 823                 if (f != cl->cl_f) {
 824                         cl->cl_f = f;
 825                         cftree_update(cl);
 826                         update_cfmin(cl->cl_parent);
 827                 }
 828         }
 829 }
 830 
 831 static unsigned int
 832 qdisc_peek_len(struct Qdisc *sch)
 833 {
 834         struct sk_buff *skb;
 835         unsigned int len;
 836 
 837         skb = sch->ops->peek(sch);
 838         if (unlikely(skb == NULL)) {
 839                 qdisc_warn_nonwc("qdisc_peek_len", sch);
 840                 return 0;
 841         }
 842         len = qdisc_pkt_len(skb);
 843 
 844         return len;
 845 }
 846 
 847 static void
 848 hfsc_adjust_levels(struct hfsc_class *cl)
 849 {
 850         struct hfsc_class *p;
 851         unsigned int level;
 852 
 853         do {
 854                 level = 0;
 855                 list_for_each_entry(p, &cl->children, siblings) {
 856                         if (p->level >= level)
 857                                 level = p->level + 1;
 858                 }
 859                 cl->level = level;
 860         } while ((cl = cl->cl_parent) != NULL);
 861 }
 862 
 863 static inline struct hfsc_class *
 864 hfsc_find_class(u32 classid, struct Qdisc *sch)
 865 {
 866         struct hfsc_sched *q = qdisc_priv(sch);
 867         struct Qdisc_class_common *clc;
 868 
 869         clc = qdisc_class_find(&q->clhash, classid);
 870         if (clc == NULL)
 871                 return NULL;
 872         return container_of(clc, struct hfsc_class, cl_common);
 873 }
 874 
 875 static void
 876 hfsc_change_rsc(struct hfsc_class *cl, struct tc_service_curve *rsc,
 877                 u64 cur_time)
 878 {
 879         sc2isc(rsc, &cl->cl_rsc);
 880         rtsc_init(&cl->cl_deadline, &cl->cl_rsc, cur_time, cl->cl_cumul);
 881         cl->cl_eligible = cl->cl_deadline;
 882         if (cl->cl_rsc.sm1 <= cl->cl_rsc.sm2) {
 883                 cl->cl_eligible.dx = 0;
 884                 cl->cl_eligible.dy = 0;
 885         }
 886         cl->cl_flags |= HFSC_RSC;
 887 }
 888 
 889 static void
 890 hfsc_change_fsc(struct hfsc_class *cl, struct tc_service_curve *fsc)
 891 {
 892         sc2isc(fsc, &cl->cl_fsc);
 893         rtsc_init(&cl->cl_virtual, &cl->cl_fsc, cl->cl_vt, cl->cl_total);
 894         cl->cl_flags |= HFSC_FSC;
 895 }
 896 
 897 static void
 898 hfsc_change_usc(struct hfsc_class *cl, struct tc_service_curve *usc,
 899                 u64 cur_time)
 900 {
 901         sc2isc(usc, &cl->cl_usc);
 902         rtsc_init(&cl->cl_ulimit, &cl->cl_usc, cur_time, cl->cl_total);
 903         cl->cl_flags |= HFSC_USC;
 904 }
 905 
 906 static const struct nla_policy hfsc_policy[TCA_HFSC_MAX + 1] = {
 907         [TCA_HFSC_RSC]  = { .len = sizeof(struct tc_service_curve) },
 908         [TCA_HFSC_FSC]  = { .len = sizeof(struct tc_service_curve) },
 909         [TCA_HFSC_USC]  = { .len = sizeof(struct tc_service_curve) },
 910 };
 911 
 912 static int
 913 hfsc_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
 914                   struct nlattr **tca, unsigned long *arg,
 915                   struct netlink_ext_ack *extack)
 916 {
 917         struct hfsc_sched *q = qdisc_priv(sch);
 918         struct hfsc_class *cl = (struct hfsc_class *)*arg;
 919         struct hfsc_class *parent = NULL;
 920         struct nlattr *opt = tca[TCA_OPTIONS];
 921         struct nlattr *tb[TCA_HFSC_MAX + 1];
 922         struct tc_service_curve *rsc = NULL, *fsc = NULL, *usc = NULL;
 923         u64 cur_time;
 924         int err;
 925 
 926         if (opt == NULL)
 927                 return -EINVAL;
 928 
 929         err = nla_parse_nested_deprecated(tb, TCA_HFSC_MAX, opt, hfsc_policy,
 930                                           NULL);
 931         if (err < 0)
 932                 return err;
 933 
 934         if (tb[TCA_HFSC_RSC]) {
 935                 rsc = nla_data(tb[TCA_HFSC_RSC]);
 936                 if (rsc->m1 == 0 && rsc->m2 == 0)
 937                         rsc = NULL;
 938         }
 939 
 940         if (tb[TCA_HFSC_FSC]) {
 941                 fsc = nla_data(tb[TCA_HFSC_FSC]);
 942                 if (fsc->m1 == 0 && fsc->m2 == 0)
 943                         fsc = NULL;
 944         }
 945 
 946         if (tb[TCA_HFSC_USC]) {
 947                 usc = nla_data(tb[TCA_HFSC_USC]);
 948                 if (usc->m1 == 0 && usc->m2 == 0)
 949                         usc = NULL;
 950         }
 951 
 952         if (cl != NULL) {
 953                 int old_flags;
 954 
 955                 if (parentid) {
 956                         if (cl->cl_parent &&
 957                             cl->cl_parent->cl_common.classid != parentid)
 958                                 return -EINVAL;
 959                         if (cl->cl_parent == NULL && parentid != TC_H_ROOT)
 960                                 return -EINVAL;
 961                 }
 962                 cur_time = psched_get_time();
 963 
 964                 if (tca[TCA_RATE]) {
 965                         err = gen_replace_estimator(&cl->bstats, NULL,
 966                                                     &cl->rate_est,
 967                                                     NULL,
 968                                                     qdisc_root_sleeping_running(sch),
 969                                                     tca[TCA_RATE]);
 970                         if (err)
 971                                 return err;
 972                 }
 973 
 974                 sch_tree_lock(sch);
 975                 old_flags = cl->cl_flags;
 976 
 977                 if (rsc != NULL)
 978                         hfsc_change_rsc(cl, rsc, cur_time);
 979                 if (fsc != NULL)
 980                         hfsc_change_fsc(cl, fsc);
 981                 if (usc != NULL)
 982                         hfsc_change_usc(cl, usc, cur_time);
 983 
 984                 if (cl->qdisc->q.qlen != 0) {
 985                         int len = qdisc_peek_len(cl->qdisc);
 986 
 987                         if (cl->cl_flags & HFSC_RSC) {
 988                                 if (old_flags & HFSC_RSC)
 989                                         update_ed(cl, len);
 990                                 else
 991                                         init_ed(cl, len);
 992                         }
 993 
 994                         if (cl->cl_flags & HFSC_FSC) {
 995                                 if (old_flags & HFSC_FSC)
 996                                         update_vf(cl, 0, cur_time);
 997                                 else
 998                                         init_vf(cl, len);
 999                         }
1000                 }
1001                 sch_tree_unlock(sch);
1002 
1003                 return 0;
1004         }
1005 
1006         if (parentid == TC_H_ROOT)
1007                 return -EEXIST;
1008 
1009         parent = &q->root;
1010         if (parentid) {
1011                 parent = hfsc_find_class(parentid, sch);
1012                 if (parent == NULL)
1013                         return -ENOENT;
1014         }
1015 
1016         if (classid == 0 || TC_H_MAJ(classid ^ sch->handle) != 0)
1017                 return -EINVAL;
1018         if (hfsc_find_class(classid, sch))
1019                 return -EEXIST;
1020 
1021         if (rsc == NULL && fsc == NULL)
1022                 return -EINVAL;
1023 
1024         cl = kzalloc(sizeof(struct hfsc_class), GFP_KERNEL);
1025         if (cl == NULL)
1026                 return -ENOBUFS;
1027 
1028         err = tcf_block_get(&cl->block, &cl->filter_list, sch, extack);
1029         if (err) {
1030                 kfree(cl);
1031                 return err;
1032         }
1033 
1034         if (tca[TCA_RATE]) {
1035                 err = gen_new_estimator(&cl->bstats, NULL, &cl->rate_est,
1036                                         NULL,
1037                                         qdisc_root_sleeping_running(sch),
1038                                         tca[TCA_RATE]);
1039                 if (err) {
1040                         tcf_block_put(cl->block);
1041                         kfree(cl);
1042                         return err;
1043                 }
1044         }
1045 
1046         if (rsc != NULL)
1047                 hfsc_change_rsc(cl, rsc, 0);
1048         if (fsc != NULL)
1049                 hfsc_change_fsc(cl, fsc);
1050         if (usc != NULL)
1051                 hfsc_change_usc(cl, usc, 0);
1052 
1053         cl->cl_common.classid = classid;
1054         cl->sched     = q;
1055         cl->cl_parent = parent;
1056         cl->qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1057                                       classid, NULL);
1058         if (cl->qdisc == NULL)
1059                 cl->qdisc = &noop_qdisc;
1060         else
1061                 qdisc_hash_add(cl->qdisc, true);
1062         INIT_LIST_HEAD(&cl->children);
1063         cl->vt_tree = RB_ROOT;
1064         cl->cf_tree = RB_ROOT;
1065 
1066         sch_tree_lock(sch);
1067         qdisc_class_hash_insert(&q->clhash, &cl->cl_common);
1068         list_add_tail(&cl->siblings, &parent->children);
1069         if (parent->level == 0)
1070                 qdisc_purge_queue(parent->qdisc);
1071         hfsc_adjust_levels(parent);
1072         sch_tree_unlock(sch);
1073 
1074         qdisc_class_hash_grow(sch, &q->clhash);
1075 
1076         *arg = (unsigned long)cl;
1077         return 0;
1078 }
1079 
1080 static void
1081 hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
1082 {
1083         struct hfsc_sched *q = qdisc_priv(sch);
1084 
1085         tcf_block_put(cl->block);
1086         qdisc_put(cl->qdisc);
1087         gen_kill_estimator(&cl->rate_est);
1088         if (cl != &q->root)
1089                 kfree(cl);
1090 }
1091 
1092 static int
1093 hfsc_delete_class(struct Qdisc *sch, unsigned long arg)
1094 {
1095         struct hfsc_sched *q = qdisc_priv(sch);
1096         struct hfsc_class *cl = (struct hfsc_class *)arg;
1097 
1098         if (cl->level > 0 || cl->filter_cnt > 0 || cl == &q->root)
1099                 return -EBUSY;
1100 
1101         sch_tree_lock(sch);
1102 
1103         list_del(&cl->siblings);
1104         hfsc_adjust_levels(cl->cl_parent);
1105 
1106         qdisc_purge_queue(cl->qdisc);
1107         qdisc_class_hash_remove(&q->clhash, &cl->cl_common);
1108 
1109         sch_tree_unlock(sch);
1110 
1111         hfsc_destroy_class(sch, cl);
1112         return 0;
1113 }
1114 
1115 static struct hfsc_class *
1116 hfsc_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
1117 {
1118         struct hfsc_sched *q = qdisc_priv(sch);
1119         struct hfsc_class *head, *cl;
1120         struct tcf_result res;
1121         struct tcf_proto *tcf;
1122         int result;
1123 
1124         if (TC_H_MAJ(skb->priority ^ sch->handle) == 0 &&
1125             (cl = hfsc_find_class(skb->priority, sch)) != NULL)
1126                 if (cl->level == 0)
1127                         return cl;
1128 
1129         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
1130         head = &q->root;
1131         tcf = rcu_dereference_bh(q->root.filter_list);
1132         while (tcf && (result = tcf_classify(skb, tcf, &res, false)) >= 0) {
1133 #ifdef CONFIG_NET_CLS_ACT
1134                 switch (result) {
1135                 case TC_ACT_QUEUED:
1136                 case TC_ACT_STOLEN:
1137                 case TC_ACT_TRAP:
1138                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
1139                         /* fall through */
1140                 case TC_ACT_SHOT:
1141                         return NULL;
1142                 }
1143 #endif
1144                 cl = (struct hfsc_class *)res.class;
1145                 if (!cl) {
1146                         cl = hfsc_find_class(res.classid, sch);
1147                         if (!cl)
1148                                 break; /* filter selected invalid classid */
1149                         if (cl->level >= head->level)
1150                                 break; /* filter may only point downwards */
1151                 }
1152 
1153                 if (cl->level == 0)
1154                         return cl; /* hit leaf class */
1155 
1156                 /* apply inner filter chain */
1157                 tcf = rcu_dereference_bh(cl->filter_list);
1158                 head = cl;
1159         }
1160 
1161         /* classification failed, try default class */
1162         cl = hfsc_find_class(TC_H_MAKE(TC_H_MAJ(sch->handle), q->defcls), sch);
1163         if (cl == NULL || cl->level > 0)
1164                 return NULL;
1165 
1166         return cl;
1167 }
1168 
1169 static int
1170 hfsc_graft_class(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
1171                  struct Qdisc **old, struct netlink_ext_ack *extack)
1172 {
1173         struct hfsc_class *cl = (struct hfsc_class *)arg;
1174 
1175         if (cl->level > 0)
1176                 return -EINVAL;
1177         if (new == NULL) {
1178                 new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1179                                         cl->cl_common.classid, NULL);
1180                 if (new == NULL)
1181                         new = &noop_qdisc;
1182         }
1183 
1184         *old = qdisc_replace(sch, new, &cl->qdisc);
1185         return 0;
1186 }
1187 
1188 static struct Qdisc *
1189 hfsc_class_leaf(struct Qdisc *sch, unsigned long arg)
1190 {
1191         struct hfsc_class *cl = (struct hfsc_class *)arg;
1192 
1193         if (cl->level == 0)
1194                 return cl->qdisc;
1195 
1196         return NULL;
1197 }
1198 
1199 static void
1200 hfsc_qlen_notify(struct Qdisc *sch, unsigned long arg)
1201 {
1202         struct hfsc_class *cl = (struct hfsc_class *)arg;
1203 
1204         /* vttree is now handled in update_vf() so that update_vf(cl, 0, 0)
1205          * needs to be called explicitly to remove a class from vttree.
1206          */
1207         update_vf(cl, 0, 0);
1208         if (cl->cl_flags & HFSC_RSC)
1209                 eltree_remove(cl);
1210 }
1211 
1212 static unsigned long
1213 hfsc_search_class(struct Qdisc *sch, u32 classid)
1214 {
1215         return (unsigned long)hfsc_find_class(classid, sch);
1216 }
1217 
1218 static unsigned long
1219 hfsc_bind_tcf(struct Qdisc *sch, unsigned long parent, u32 classid)
1220 {
1221         struct hfsc_class *p = (struct hfsc_class *)parent;
1222         struct hfsc_class *cl = hfsc_find_class(classid, sch);
1223 
1224         if (cl != NULL) {
1225                 if (p != NULL && p->level <= cl->level)
1226                         return 0;
1227                 cl->filter_cnt++;
1228         }
1229 
1230         return (unsigned long)cl;
1231 }
1232 
1233 static void
1234 hfsc_unbind_tcf(struct Qdisc *sch, unsigned long arg)
1235 {
1236         struct hfsc_class *cl = (struct hfsc_class *)arg;
1237 
1238         cl->filter_cnt--;
1239 }
1240 
1241 static struct tcf_block *hfsc_tcf_block(struct Qdisc *sch, unsigned long arg,
1242                                         struct netlink_ext_ack *extack)
1243 {
1244         struct hfsc_sched *q = qdisc_priv(sch);
1245         struct hfsc_class *cl = (struct hfsc_class *)arg;
1246 
1247         if (cl == NULL)
1248                 cl = &q->root;
1249 
1250         return cl->block;
1251 }
1252 
1253 static int
1254 hfsc_dump_sc(struct sk_buff *skb, int attr, struct internal_sc *sc)
1255 {
1256         struct tc_service_curve tsc;
1257 
1258         tsc.m1 = sm2m(sc->sm1);
1259         tsc.d  = dx2d(sc->dx);
1260         tsc.m2 = sm2m(sc->sm2);
1261         if (nla_put(skb, attr, sizeof(tsc), &tsc))
1262                 goto nla_put_failure;
1263 
1264         return skb->len;
1265 
1266  nla_put_failure:
1267         return -1;
1268 }
1269 
1270 static int
1271 hfsc_dump_curves(struct sk_buff *skb, struct hfsc_class *cl)
1272 {
1273         if ((cl->cl_flags & HFSC_RSC) &&
1274             (hfsc_dump_sc(skb, TCA_HFSC_RSC, &cl->cl_rsc) < 0))
1275                 goto nla_put_failure;
1276 
1277         if ((cl->cl_flags & HFSC_FSC) &&
1278             (hfsc_dump_sc(skb, TCA_HFSC_FSC, &cl->cl_fsc) < 0))
1279                 goto nla_put_failure;
1280 
1281         if ((cl->cl_flags & HFSC_USC) &&
1282             (hfsc_dump_sc(skb, TCA_HFSC_USC, &cl->cl_usc) < 0))
1283                 goto nla_put_failure;
1284 
1285         return skb->len;
1286 
1287  nla_put_failure:
1288         return -1;
1289 }
1290 
1291 static int
1292 hfsc_dump_class(struct Qdisc *sch, unsigned long arg, struct sk_buff *skb,
1293                 struct tcmsg *tcm)
1294 {
1295         struct hfsc_class *cl = (struct hfsc_class *)arg;
1296         struct nlattr *nest;
1297 
1298         tcm->tcm_parent = cl->cl_parent ? cl->cl_parent->cl_common.classid :
1299                                           TC_H_ROOT;
1300         tcm->tcm_handle = cl->cl_common.classid;
1301         if (cl->level == 0)
1302                 tcm->tcm_info = cl->qdisc->handle;
1303 
1304         nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1305         if (nest == NULL)
1306                 goto nla_put_failure;
1307         if (hfsc_dump_curves(skb, cl) < 0)
1308                 goto nla_put_failure;
1309         return nla_nest_end(skb, nest);
1310 
1311  nla_put_failure:
1312         nla_nest_cancel(skb, nest);
1313         return -EMSGSIZE;
1314 }
1315 
1316 static int
1317 hfsc_dump_class_stats(struct Qdisc *sch, unsigned long arg,
1318         struct gnet_dump *d)
1319 {
1320         struct hfsc_class *cl = (struct hfsc_class *)arg;
1321         struct tc_hfsc_stats xstats;
1322         __u32 qlen;
1323 
1324         qdisc_qstats_qlen_backlog(cl->qdisc, &qlen, &cl->qstats.backlog);
1325         xstats.level   = cl->level;
1326         xstats.period  = cl->cl_vtperiod;
1327         xstats.work    = cl->cl_total;
1328         xstats.rtwork  = cl->cl_cumul;
1329 
1330         if (gnet_stats_copy_basic(qdisc_root_sleeping_running(sch), d, NULL, &cl->bstats) < 0 ||
1331             gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||
1332             gnet_stats_copy_queue(d, NULL, &cl->qstats, qlen) < 0)
1333                 return -1;
1334 
1335         return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
1336 }
1337 
1338 
1339 
1340 static void
1341 hfsc_walk(struct Qdisc *sch, struct qdisc_walker *arg)
1342 {
1343         struct hfsc_sched *q = qdisc_priv(sch);
1344         struct hfsc_class *cl;
1345         unsigned int i;
1346 
1347         if (arg->stop)
1348                 return;
1349 
1350         for (i = 0; i < q->clhash.hashsize; i++) {
1351                 hlist_for_each_entry(cl, &q->clhash.hash[i],
1352                                      cl_common.hnode) {
1353                         if (arg->count < arg->skip) {
1354                                 arg->count++;
1355                                 continue;
1356                         }
1357                         if (arg->fn(sch, (unsigned long)cl, arg) < 0) {
1358                                 arg->stop = 1;
1359                                 return;
1360                         }
1361                         arg->count++;
1362                 }
1363         }
1364 }
1365 
1366 static void
1367 hfsc_schedule_watchdog(struct Qdisc *sch)
1368 {
1369         struct hfsc_sched *q = qdisc_priv(sch);
1370         struct hfsc_class *cl;
1371         u64 next_time = 0;
1372 
1373         cl = eltree_get_minel(q);
1374         if (cl)
1375                 next_time = cl->cl_e;
1376         if (q->root.cl_cfmin != 0) {
1377                 if (next_time == 0 || next_time > q->root.cl_cfmin)
1378                         next_time = q->root.cl_cfmin;
1379         }
1380         if (next_time)
1381                 qdisc_watchdog_schedule(&q->watchdog, next_time);
1382 }
1383 
1384 static int
1385 hfsc_init_qdisc(struct Qdisc *sch, struct nlattr *opt,
1386                 struct netlink_ext_ack *extack)
1387 {
1388         struct hfsc_sched *q = qdisc_priv(sch);
1389         struct tc_hfsc_qopt *qopt;
1390         int err;
1391 
1392         qdisc_watchdog_init(&q->watchdog, sch);
1393 
1394         if (!opt || nla_len(opt) < sizeof(*qopt))
1395                 return -EINVAL;
1396         qopt = nla_data(opt);
1397 
1398         q->defcls = qopt->defcls;
1399         err = qdisc_class_hash_init(&q->clhash);
1400         if (err < 0)
1401                 return err;
1402         q->eligible = RB_ROOT;
1403 
1404         err = tcf_block_get(&q->root.block, &q->root.filter_list, sch, extack);
1405         if (err)
1406                 return err;
1407 
1408         q->root.cl_common.classid = sch->handle;
1409         q->root.sched   = q;
1410         q->root.qdisc = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
1411                                           sch->handle, NULL);
1412         if (q->root.qdisc == NULL)
1413                 q->root.qdisc = &noop_qdisc;
1414         else
1415                 qdisc_hash_add(q->root.qdisc, true);
1416         INIT_LIST_HEAD(&q->root.children);
1417         q->root.vt_tree = RB_ROOT;
1418         q->root.cf_tree = RB_ROOT;
1419 
1420         qdisc_class_hash_insert(&q->clhash, &q->root.cl_common);
1421         qdisc_class_hash_grow(sch, &q->clhash);
1422 
1423         return 0;
1424 }
1425 
1426 static int
1427 hfsc_change_qdisc(struct Qdisc *sch, struct nlattr *opt,
1428                   struct netlink_ext_ack *extack)
1429 {
1430         struct hfsc_sched *q = qdisc_priv(sch);
1431         struct tc_hfsc_qopt *qopt;
1432 
1433         if (opt == NULL || nla_len(opt) < sizeof(*qopt))
1434                 return -EINVAL;
1435         qopt = nla_data(opt);
1436 
1437         sch_tree_lock(sch);
1438         q->defcls = qopt->defcls;
1439         sch_tree_unlock(sch);
1440 
1441         return 0;
1442 }
1443 
1444 static void
1445 hfsc_reset_class(struct hfsc_class *cl)
1446 {
1447         cl->cl_total        = 0;
1448         cl->cl_cumul        = 0;
1449         cl->cl_d            = 0;
1450         cl->cl_e            = 0;
1451         cl->cl_vt           = 0;
1452         cl->cl_vtadj        = 0;
1453         cl->cl_cvtmin       = 0;
1454         cl->cl_cvtoff       = 0;
1455         cl->cl_vtperiod     = 0;
1456         cl->cl_parentperiod = 0;
1457         cl->cl_f            = 0;
1458         cl->cl_myf          = 0;
1459         cl->cl_cfmin        = 0;
1460         cl->cl_nactive      = 0;
1461 
1462         cl->vt_tree = RB_ROOT;
1463         cl->cf_tree = RB_ROOT;
1464         qdisc_reset(cl->qdisc);
1465 
1466         if (cl->cl_flags & HFSC_RSC)
1467                 rtsc_init(&cl->cl_deadline, &cl->cl_rsc, 0, 0);
1468         if (cl->cl_flags & HFSC_FSC)
1469                 rtsc_init(&cl->cl_virtual, &cl->cl_fsc, 0, 0);
1470         if (cl->cl_flags & HFSC_USC)
1471                 rtsc_init(&cl->cl_ulimit, &cl->cl_usc, 0, 0);
1472 }
1473 
1474 static void
1475 hfsc_reset_qdisc(struct Qdisc *sch)
1476 {
1477         struct hfsc_sched *q = qdisc_priv(sch);
1478         struct hfsc_class *cl;
1479         unsigned int i;
1480 
1481         for (i = 0; i < q->clhash.hashsize; i++) {
1482                 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode)
1483                         hfsc_reset_class(cl);
1484         }
1485         q->eligible = RB_ROOT;
1486         qdisc_watchdog_cancel(&q->watchdog);
1487         sch->qstats.backlog = 0;
1488         sch->q.qlen = 0;
1489 }
1490 
1491 static void
1492 hfsc_destroy_qdisc(struct Qdisc *sch)
1493 {
1494         struct hfsc_sched *q = qdisc_priv(sch);
1495         struct hlist_node *next;
1496         struct hfsc_class *cl;
1497         unsigned int i;
1498 
1499         for (i = 0; i < q->clhash.hashsize; i++) {
1500                 hlist_for_each_entry(cl, &q->clhash.hash[i], cl_common.hnode) {
1501                         tcf_block_put(cl->block);
1502                         cl->block = NULL;
1503                 }
1504         }
1505         for (i = 0; i < q->clhash.hashsize; i++) {
1506                 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[i],
1507                                           cl_common.hnode)
1508                         hfsc_destroy_class(sch, cl);
1509         }
1510         qdisc_class_hash_destroy(&q->clhash);
1511         qdisc_watchdog_cancel(&q->watchdog);
1512 }
1513 
1514 static int
1515 hfsc_dump_qdisc(struct Qdisc *sch, struct sk_buff *skb)
1516 {
1517         struct hfsc_sched *q = qdisc_priv(sch);
1518         unsigned char *b = skb_tail_pointer(skb);
1519         struct tc_hfsc_qopt qopt;
1520 
1521         qopt.defcls = q->defcls;
1522         if (nla_put(skb, TCA_OPTIONS, sizeof(qopt), &qopt))
1523                 goto nla_put_failure;
1524         return skb->len;
1525 
1526  nla_put_failure:
1527         nlmsg_trim(skb, b);
1528         return -1;
1529 }
1530 
1531 static int
1532 hfsc_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free)
1533 {
1534         unsigned int len = qdisc_pkt_len(skb);
1535         struct hfsc_class *cl;
1536         int uninitialized_var(err);
1537         bool first;
1538 
1539         cl = hfsc_classify(skb, sch, &err);
1540         if (cl == NULL) {
1541                 if (err & __NET_XMIT_BYPASS)
1542                         qdisc_qstats_drop(sch);
1543                 __qdisc_drop(skb, to_free);
1544                 return err;
1545         }
1546 
1547         first = !cl->qdisc->q.qlen;
1548         err = qdisc_enqueue(skb, cl->qdisc, to_free);
1549         if (unlikely(err != NET_XMIT_SUCCESS)) {
1550                 if (net_xmit_drop_count(err)) {
1551                         cl->qstats.drops++;
1552                         qdisc_qstats_drop(sch);
1553                 }
1554                 return err;
1555         }
1556 
1557         if (first) {
1558                 if (cl->cl_flags & HFSC_RSC)
1559                         init_ed(cl, len);
1560                 if (cl->cl_flags & HFSC_FSC)
1561                         init_vf(cl, len);
1562                 /*
1563                  * If this is the first packet, isolate the head so an eventual
1564                  * head drop before the first dequeue operation has no chance
1565                  * to invalidate the deadline.
1566                  */
1567                 if (cl->cl_flags & HFSC_RSC)
1568                         cl->qdisc->ops->peek(cl->qdisc);
1569 
1570         }
1571 
1572         sch->qstats.backlog += len;
1573         sch->q.qlen++;
1574 
1575         return NET_XMIT_SUCCESS;
1576 }
1577 
1578 static struct sk_buff *
1579 hfsc_dequeue(struct Qdisc *sch)
1580 {
1581         struct hfsc_sched *q = qdisc_priv(sch);
1582         struct hfsc_class *cl;
1583         struct sk_buff *skb;
1584         u64 cur_time;
1585         unsigned int next_len;
1586         int realtime = 0;
1587 
1588         if (sch->q.qlen == 0)
1589                 return NULL;
1590 
1591         cur_time = psched_get_time();
1592 
1593         /*
1594          * if there are eligible classes, use real-time criteria.
1595          * find the class with the minimum deadline among
1596          * the eligible classes.
1597          */
1598         cl = eltree_get_mindl(q, cur_time);
1599         if (cl) {
1600                 realtime = 1;
1601         } else {
1602                 /*
1603                  * use link-sharing criteria
1604                  * get the class with the minimum vt in the hierarchy
1605                  */
1606                 cl = vttree_get_minvt(&q->root, cur_time);
1607                 if (cl == NULL) {
1608                         qdisc_qstats_overlimit(sch);
1609                         hfsc_schedule_watchdog(sch);
1610                         return NULL;
1611                 }
1612         }
1613 
1614         skb = qdisc_dequeue_peeked(cl->qdisc);
1615         if (skb == NULL) {
1616                 qdisc_warn_nonwc("HFSC", cl->qdisc);
1617                 return NULL;
1618         }
1619 
1620         bstats_update(&cl->bstats, skb);
1621         update_vf(cl, qdisc_pkt_len(skb), cur_time);
1622         if (realtime)
1623                 cl->cl_cumul += qdisc_pkt_len(skb);
1624 
1625         if (cl->cl_flags & HFSC_RSC) {
1626                 if (cl->qdisc->q.qlen != 0) {
1627                         /* update ed */
1628                         next_len = qdisc_peek_len(cl->qdisc);
1629                         if (realtime)
1630                                 update_ed(cl, next_len);
1631                         else
1632                                 update_d(cl, next_len);
1633                 } else {
1634                         /* the class becomes passive */
1635                         eltree_remove(cl);
1636                 }
1637         }
1638 
1639         qdisc_bstats_update(sch, skb);
1640         qdisc_qstats_backlog_dec(sch, skb);
1641         sch->q.qlen--;
1642 
1643         return skb;
1644 }
1645 
1646 static const struct Qdisc_class_ops hfsc_class_ops = {
1647         .change         = hfsc_change_class,
1648         .delete         = hfsc_delete_class,
1649         .graft          = hfsc_graft_class,
1650         .leaf           = hfsc_class_leaf,
1651         .qlen_notify    = hfsc_qlen_notify,
1652         .find           = hfsc_search_class,
1653         .bind_tcf       = hfsc_bind_tcf,
1654         .unbind_tcf     = hfsc_unbind_tcf,
1655         .tcf_block      = hfsc_tcf_block,
1656         .dump           = hfsc_dump_class,
1657         .dump_stats     = hfsc_dump_class_stats,
1658         .walk           = hfsc_walk
1659 };
1660 
1661 static struct Qdisc_ops hfsc_qdisc_ops __read_mostly = {
1662         .id             = "hfsc",
1663         .init           = hfsc_init_qdisc,
1664         .change         = hfsc_change_qdisc,
1665         .reset          = hfsc_reset_qdisc,
1666         .destroy        = hfsc_destroy_qdisc,
1667         .dump           = hfsc_dump_qdisc,
1668         .enqueue        = hfsc_enqueue,
1669         .dequeue        = hfsc_dequeue,
1670         .peek           = qdisc_peek_dequeued,
1671         .cl_ops         = &hfsc_class_ops,
1672         .priv_size      = sizeof(struct hfsc_sched),
1673         .owner          = THIS_MODULE
1674 };
1675 
1676 static int __init
1677 hfsc_init(void)
1678 {
1679         return register_qdisc(&hfsc_qdisc_ops);
1680 }
1681 
1682 static void __exit
1683 hfsc_cleanup(void)
1684 {
1685         unregister_qdisc(&hfsc_qdisc_ops);
1686 }
1687 
1688 MODULE_LICENSE("GPL");
1689 module_init(hfsc_init);
1690 module_exit(hfsc_cleanup);
/* [<][>][^][v][top][bottom][index][help] */
root/net/sched/sch_hfsc.c

DEFINITIONS
