include/net/sch_generic.h

   1 #ifndef __NET_SCHED_GENERIC_H
   2 #define __NET_SCHED_GENERIC_H
   3
   4 #include <linux/netdevice.h>
   5 #include <linux/types.h>
   6 #include <linux/rcupdate.h>
   7 #include <linux/pkt_sched.h>
   8 #include <linux/pkt_cls.h>
   9 #include <linux/percpu.h>
  10 #include <linux/dynamic_queue_limits.h>
  11 #include <net/gen_stats.h>
  12 #include <net/rtnetlink.h>
  13
  14 struct Qdisc_ops;
  15 struct qdisc_walker;
  16 struct tcf_walker;
  17 struct module;
  18
  19 struct qdisc_rate_table {
  20         struct tc_ratespec rate;
  21         u32             data[256];
  22         struct qdisc_rate_table *next;
  23         int             refcnt;
  24 };
  25
  26 enum qdisc_state_t {
  27         __QDISC_STATE_SCHED,
  28         __QDISC_STATE_DEACTIVATED,
  29         __QDISC_STATE_THROTTLED,
  30 };
  31
  32 /*
  33  * following bits are only changed while qdisc lock is held
  34  */
  35 enum qdisc___state_t {
  36         __QDISC___STATE_RUNNING = 1,
  37 };
  38
  39 struct qdisc_size_table {
  40         struct rcu_head         rcu;
  41         struct list_head        list;
  42         struct tc_sizespec      szopts;
  43         int                     refcnt;
  44         u16                     data[];
  45 };
  46
  47 struct Qdisc {
  48         int                     (*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
  49         struct sk_buff *        (*dequeue)(struct Qdisc *dev);
  50         unsigned int            flags;
  51 #define TCQ_F_BUILTIN           1
  52 #define TCQ_F_INGRESS           2
  53 #define TCQ_F_CAN_BYPASS        4
  54 #define TCQ_F_MQROOT            8
  55 #define TCQ_F_ONETXQUEUE        0x10 /* dequeue_skb() can assume all skbs are for
  56                                       * q->dev_queue : It can test
  57                                       * netif_xmit_frozen_or_stopped() before
  58                                       * dequeueing next packet.
  59                                       * Its true for MQ/MQPRIO slaves, or non
  60                                       * multiqueue device.
  61                                       */
  62 #define TCQ_F_WARN_NONWC        (1 << 16)
  63 #define TCQ_F_CPUSTATS          0x20 /* run using percpu statistics */
  64 #define TCQ_F_NOPARENT          0x40 /* root of its hierarchy :
  65                                       * qdisc_tree_decrease_qlen() should stop.
  66                                       */
  67         u32                     limit;
  68         const struct Qdisc_ops  *ops;
  69         struct qdisc_size_table __rcu *stab;
  70         struct list_head        list;
  71         u32                     handle;
  72         u32                     parent;
  73         int                     (*reshape_fail)(struct sk_buff *skb,
  74                                         struct Qdisc *q);
  75
  76         void                    *u32_node;
  77
  78         /* This field is deprecated, but it is still used by CBQ
  79          * and it will live until better solution will be invented.
  80          */
  81         struct Qdisc            *__parent;
  82         struct netdev_queue     *dev_queue;
  83
  84         struct gnet_stats_rate_est64    rate_est;
  85         struct gnet_stats_basic_cpu __percpu *cpu_bstats;
  86         struct gnet_stats_queue __percpu *cpu_qstats;
  87
  88         struct Qdisc            *next_sched;
  89         struct sk_buff          *gso_skb;
  90         /*
  91          * For performance sake on SMP, we put highly modified fields at the end
  92          */
  93         unsigned long           state;
  94         struct sk_buff_head     q;
  95         struct gnet_stats_basic_packed bstats;
  96         unsigned int            __state;
  97         struct gnet_stats_queue qstats;
  98         struct rcu_head         rcu_head;
  99         int                     padded;
 100         atomic_t                refcnt;
 101
 102         spinlock_t              busylock ____cacheline_aligned_in_smp;
 103 };
 104
 105 static inline bool qdisc_is_running(const struct Qdisc *qdisc)
 106 {
 107         return (qdisc->__state & __QDISC___STATE_RUNNING) ? true : false;
 108 }
 109
 110 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 111 {
 112         if (qdisc_is_running(qdisc))
 113                 return false;
 114         qdisc->__state |= __QDISC___STATE_RUNNING;
 115         return true;
 116 }
 117
 118 static inline void qdisc_run_end(struct Qdisc *qdisc)
 119 {
 120         qdisc->__state &= ~__QDISC___STATE_RUNNING;
 121 }
 122
 123 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
 124 {
 125         return qdisc->flags & TCQ_F_ONETXQUEUE;
 126 }
 127
 128 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
 129 {
 130 #ifdef CONFIG_BQL
 131         /* Non-BQL migrated drivers will return 0, too. */
 132         return dql_avail(&txq->dql);
 133 #else
 134         return 0;
 135 #endif
 136 }
 137
 138 static inline bool qdisc_is_throttled(const struct Qdisc *qdisc)
 139 {
 140         return test_bit(__QDISC_STATE_THROTTLED, &qdisc->state) ? true : false;
 141 }
 142
 143 static inline void qdisc_throttled(struct Qdisc *qdisc)
 144 {
 145         set_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
 146 }
 147
 148 static inline void qdisc_unthrottled(struct Qdisc *qdisc)
 149 {
 150         clear_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
 151 }
 152
 153 struct Qdisc_class_ops {
 154         /* Child qdisc manipulation */
 155         struct netdev_queue *   (*select_queue)(struct Qdisc *, struct tcmsg *);
 156         int                     (*graft)(struct Qdisc *, unsigned long cl,
 157                                         struct Qdisc *, struct Qdisc **);
 158         struct Qdisc *          (*leaf)(struct Qdisc *, unsigned long cl);
 159         void                    (*qlen_notify)(struct Qdisc *, unsigned long);
 160
 161         /* Class manipulation routines */
 162         unsigned long           (*get)(struct Qdisc *, u32 classid);
 163         void                    (*put)(struct Qdisc *, unsigned long);
 164         int                     (*change)(struct Qdisc *, u32, u32,
 165                                         struct nlattr **, unsigned long *);
 166         int                     (*delete)(struct Qdisc *, unsigned long);
 167         void                    (*walk)(struct Qdisc *, struct qdisc_walker * arg);
 168
 169         /* Filter manipulation */
 170         struct tcf_proto __rcu ** (*tcf_chain)(struct Qdisc *, unsigned long);
 171         bool                    (*tcf_cl_offload)(u32 classid);
 172         unsigned long           (*bind_tcf)(struct Qdisc *, unsigned long,
 173                                         u32 classid);
 174         void                    (*unbind_tcf)(struct Qdisc *, unsigned long);
 175
 176         /* rtnetlink specific */
 177         int                     (*dump)(struct Qdisc *, unsigned long,
 178                                         struct sk_buff *skb, struct tcmsg*);
 179         int                     (*dump_stats)(struct Qdisc *, unsigned long,
 180                                         struct gnet_dump *);
 181 };
 182
 183 struct Qdisc_ops {
 184         struct Qdisc_ops        *next;
 185         const struct Qdisc_class_ops    *cl_ops;
 186         char                    id[IFNAMSIZ];
 187         int                     priv_size;
 188
 189         int                     (*enqueue)(struct sk_buff *, struct Qdisc *);
 190         struct sk_buff *        (*dequeue)(struct Qdisc *);
 191         struct sk_buff *        (*peek)(struct Qdisc *);
 192         unsigned int            (*drop)(struct Qdisc *);
 193
 194         int                     (*init)(struct Qdisc *, struct nlattr *arg);
 195         void                    (*reset)(struct Qdisc *);
 196         void                    (*destroy)(struct Qdisc *);
 197         int                     (*change)(struct Qdisc *, struct nlattr *arg);
 198         void                    (*attach)(struct Qdisc *);
 199
 200         int                     (*dump)(struct Qdisc *, struct sk_buff *);
 201         int                     (*dump_stats)(struct Qdisc *, struct gnet_dump *);
 202
 203         struct module           *owner;
 204 };
 205
 206
 207 struct tcf_result {
 208         unsigned long   class;
 209         u32             classid;
 210 };
 211
 212 struct tcf_proto_ops {
 213         struct list_head        head;
 214         char                    kind[IFNAMSIZ];
 215
 216         int                     (*classify)(struct sk_buff *,
 217                                             const struct tcf_proto *,
 218                                             struct tcf_result *);
 219         int                     (*init)(struct tcf_proto*);
 220         bool                    (*destroy)(struct tcf_proto*, bool);
 221
 222         unsigned long           (*get)(struct tcf_proto*, u32 handle);
 223         int                     (*change)(struct net *net, struct sk_buff *,
 224                                         struct tcf_proto*, unsigned long,
 225                                         u32 handle, struct nlattr **,
 226                                         unsigned long *, bool);
 227         int                     (*delete)(struct tcf_proto*, unsigned long);
 228         void                    (*walk)(struct tcf_proto*, struct tcf_walker *arg);
 229
 230         /* rtnetlink specific */
 231         int                     (*dump)(struct net*, struct tcf_proto*, unsigned long,
 232                                         struct sk_buff *skb, struct tcmsg*);
 233
 234         struct module           *owner;
 235 };
 236
 237 struct tcf_proto {
 238         /* Fast access part */
 239         struct tcf_proto __rcu  *next;
 240         void __rcu              *root;
 241         int                     (*classify)(struct sk_buff *,
 242                                             const struct tcf_proto *,
 243                                             struct tcf_result *);
 244         __be16                  protocol;
 245
 246         /* All the rest */
 247         u32                     prio;
 248         u32                     classid;
 249         struct Qdisc            *q;
 250         void                    *data;
 251         const struct tcf_proto_ops      *ops;
 252         struct rcu_head         rcu;
 253 };
 254
 255 struct qdisc_skb_cb {
 256         unsigned int            pkt_len;
 257         u16                     slave_dev_queue_mapping;
 258         u16                     tc_classid;
 259 #define QDISC_CB_PRIV_LEN 20
 260         unsigned char           data[QDISC_CB_PRIV_LEN];
 261 };
 262
 263 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
 264 {
 265         struct qdisc_skb_cb *qcb;
 266
 267         BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
 268         BUILD_BUG_ON(sizeof(qcb->data) < sz);
 269 }
 270
 271 static inline int qdisc_qlen(const struct Qdisc *q)
 272 {
 273         return q->q.qlen;
 274 }
 275
 276 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
 277 {
 278         return (struct qdisc_skb_cb *)skb->cb;
 279 }
 280
 281 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
 282 {
 283         return &qdisc->q.lock;
 284 }
 285
 286 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
 287 {
 288         struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
 289
 290         return q;
 291 }
 292
 293 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
 294 {
 295         return qdisc->dev_queue->qdisc_sleeping;
 296 }
 297
 298 /* The qdisc root lock is a mechanism by which to top level
 299  * of a qdisc tree can be locked from any qdisc node in the
 300  * forest.  This allows changing the configuration of some
 301  * aspect of the qdisc tree while blocking out asynchronous
 302  * qdisc access in the packet processing paths.
 303  *
 304  * It is only legal to do this when the root will not change
 305  * on us.  Otherwise we'll potentially lock the wrong qdisc
 306  * root.  This is enforced by holding the RTNL semaphore, which
 307  * all users of this lock accessor must do.
 308  */
 309 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
 310 {
 311         struct Qdisc *root = qdisc_root(qdisc);
 312
 313         ASSERT_RTNL();
 314         return qdisc_lock(root);
 315 }
 316
 317 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
 318 {
 319         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 320
 321         ASSERT_RTNL();
 322         return qdisc_lock(root);
 323 }
 324
 325 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
 326 {
 327         return qdisc->dev_queue->dev;
 328 }
 329
 330 static inline void sch_tree_lock(const struct Qdisc *q)
 331 {
 332         spin_lock_bh(qdisc_root_sleeping_lock(q));
 333 }
 334
 335 static inline void sch_tree_unlock(const struct Qdisc *q)
 336 {
 337         spin_unlock_bh(qdisc_root_sleeping_lock(q));
 338 }
 339
 340 #define tcf_tree_lock(tp)       sch_tree_lock((tp)->q)
 341 #define tcf_tree_unlock(tp)     sch_tree_unlock((tp)->q)
 342
 343 extern struct Qdisc noop_qdisc;
 344 extern struct Qdisc_ops noop_qdisc_ops;
 345 extern struct Qdisc_ops pfifo_fast_ops;
 346 extern struct Qdisc_ops mq_qdisc_ops;
 347 extern struct Qdisc_ops noqueue_qdisc_ops;
 348 extern const struct Qdisc_ops *default_qdisc_ops;
 349 static inline const struct Qdisc_ops *
 350 get_default_qdisc_ops(const struct net_device *dev, int ntx)
 351 {
 352         return ntx < dev->real_num_tx_queues ?
 353                         default_qdisc_ops : &pfifo_fast_ops;
 354 }
 355
 356 struct Qdisc_class_common {
 357         u32                     classid;
 358         struct hlist_node       hnode;
 359 };
 360
 361 struct Qdisc_class_hash {
 362         struct hlist_head       *hash;
 363         unsigned int            hashsize;
 364         unsigned int            hashmask;
 365         unsigned int            hashelems;
 366 };
 367
 368 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
 369 {
 370         id ^= id >> 8;
 371         id ^= id >> 4;
 372         return id & mask;
 373 }
 374
 375 static inline struct Qdisc_class_common *
 376 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
 377 {
 378         struct Qdisc_class_common *cl;
 379         unsigned int h;
 380
 381         h = qdisc_class_hash(id, hash->hashmask);
 382         hlist_for_each_entry(cl, &hash->hash[h], hnode) {
 383                 if (cl->classid == id)
 384                         return cl;
 385         }
 386         return NULL;
 387 }
 388
 389 int qdisc_class_hash_init(struct Qdisc_class_hash *);
 390 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
 391                              struct Qdisc_class_common *);
 392 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
 393                              struct Qdisc_class_common *);
 394 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
 395 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
 396
 397 void dev_init_scheduler(struct net_device *dev);
 398 void dev_shutdown(struct net_device *dev);
 399 void dev_activate(struct net_device *dev);
 400 void dev_deactivate(struct net_device *dev);
 401 void dev_deactivate_many(struct list_head *head);
 402 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 403                               struct Qdisc *qdisc);
 404 void qdisc_reset(struct Qdisc *qdisc);
 405 void qdisc_destroy(struct Qdisc *qdisc);
 406 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
 407                                unsigned int len);
 408 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 409                           const struct Qdisc_ops *ops);
 410 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
 411                                 const struct Qdisc_ops *ops, u32 parentid);
 412 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 413                                const struct qdisc_size_table *stab);
 414 bool tcf_destroy(struct tcf_proto *tp, bool force);
 415 void tcf_destroy_chain(struct tcf_proto __rcu **fl);
 416 int skb_do_redirect(struct sk_buff *);
 417
 418 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
 419 {
 420 #ifdef CONFIG_NET_CLS_ACT
 421         return G_TC_AT(skb->tc_verd) & AT_INGRESS;
 422 #else
 423         return false;
 424 #endif
 425 }
 426
 427 /* Reset all TX qdiscs greater then index of a device.  */
 428 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
 429 {
 430         struct Qdisc *qdisc;
 431
 432         for (; i < dev->num_tx_queues; i++) {
 433                 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
 434                 if (qdisc) {
 435                         spin_lock_bh(qdisc_lock(qdisc));
 436                         qdisc_reset(qdisc);
 437                         spin_unlock_bh(qdisc_lock(qdisc));
 438                 }
 439         }
 440 }
 441
 442 static inline void qdisc_reset_all_tx(struct net_device *dev)
 443 {
 444         qdisc_reset_all_tx_gt(dev, 0);
 445 }
 446
 447 /* Are all TX queues of the device empty?  */
 448 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 449 {
 450         unsigned int i;
 451
 452         rcu_read_lock();
 453         for (i = 0; i < dev->num_tx_queues; i++) {
 454                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 455                 const struct Qdisc *q = rcu_dereference(txq->qdisc);
 456
 457                 if (q->q.qlen) {
 458                         rcu_read_unlock();
 459                         return false;
 460                 }
 461         }
 462         rcu_read_unlock();
 463         return true;
 464 }
 465
 466 /* Are any of the TX qdiscs changing?  */
 467 static inline bool qdisc_tx_changing(const struct net_device *dev)
 468 {
 469         unsigned int i;
 470
 471         for (i = 0; i < dev->num_tx_queues; i++) {
 472                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 473                 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
 474                         return true;
 475         }
 476         return false;
 477 }
 478
 479 /* Is the device using the noop qdisc on all queues?  */
 480 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
 481 {
 482         unsigned int i;
 483
 484         for (i = 0; i < dev->num_tx_queues; i++) {
 485                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 486                 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
 487                         return false;
 488         }
 489         return true;
 490 }
 491
 492 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
 493 {
 494         return qdisc_skb_cb(skb)->pkt_len;
 495 }
 496
 497 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
 498 enum net_xmit_qdisc_t {
 499         __NET_XMIT_STOLEN = 0x00010000,
 500         __NET_XMIT_BYPASS = 0x00020000,
 501 };
 502
 503 #ifdef CONFIG_NET_CLS_ACT
 504 #define net_xmit_drop_count(e)  ((e) & __NET_XMIT_STOLEN ? 0 : 1)
 505 #else
 506 #define net_xmit_drop_count(e)  (1)
 507 #endif
 508
 509 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
 510                                            const struct Qdisc *sch)
 511 {
 512 #ifdef CONFIG_NET_SCHED
 513         struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
 514
 515         if (stab)
 516                 __qdisc_calculate_pkt_len(skb, stab);
 517 #endif
 518 }
 519
 520 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 521 {
 522         qdisc_calculate_pkt_len(skb, sch);
 523         return sch->enqueue(skb, sch);
 524 }
 525
 526 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
 527 {
 528         return q->flags & TCQ_F_CPUSTATS;
 529 }
 530
 531 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
 532                                   __u64 bytes, __u32 packets)
 533 {
 534         bstats->bytes += bytes;
 535         bstats->packets += packets;
 536 }
 537
 538 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
 539                                  const struct sk_buff *skb)
 540 {
 541         _bstats_update(bstats,
 542                        qdisc_pkt_len(skb),
 543                        skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
 544 }
 545
 546 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
 547                                       __u64 bytes, __u32 packets)
 548 {
 549         u64_stats_update_begin(&bstats->syncp);
 550         _bstats_update(&bstats->bstats, bytes, packets);
 551         u64_stats_update_end(&bstats->syncp);
 552 }
 553
 554 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
 555                                      const struct sk_buff *skb)
 556 {
 557         u64_stats_update_begin(&bstats->syncp);
 558         bstats_update(&bstats->bstats, skb);
 559         u64_stats_update_end(&bstats->syncp);
 560 }
 561
 562 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
 563                                            const struct sk_buff *skb)
 564 {
 565         bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
 566 }
 567
 568 static inline void qdisc_bstats_update(struct Qdisc *sch,
 569                                        const struct sk_buff *skb)
 570 {
 571         bstats_update(&sch->bstats, skb);
 572 }
 573
 574 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
 575                                             const struct sk_buff *skb)
 576 {
 577         sch->qstats.backlog -= qdisc_pkt_len(skb);
 578 }
 579
 580 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
 581                                             const struct sk_buff *skb)
 582 {
 583         sch->qstats.backlog += qdisc_pkt_len(skb);
 584 }
 585
 586 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
 587 {
 588         sch->qstats.drops += count;
 589 }
 590
 591 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
 592 {
 593         qstats->drops++;
 594 }
 595
 596 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
 597 {
 598         qstats->overlimits++;
 599 }
 600
 601 static inline void qdisc_qstats_drop(struct Qdisc *sch)
 602 {
 603         qstats_drop_inc(&sch->qstats);
 604 }
 605
 606 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
 607 {
 608         qstats_drop_inc(this_cpu_ptr(sch->cpu_qstats));
 609 }
 610
 611 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
 612 {
 613         sch->qstats.overlimits++;
 614 }
 615
 616 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
 617                                        struct sk_buff_head *list)
 618 {
 619         __skb_queue_tail(list, skb);
 620         qdisc_qstats_backlog_inc(sch, skb);
 621
 622         return NET_XMIT_SUCCESS;
 623 }
 624
 625 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
 626 {
 627         return __qdisc_enqueue_tail(skb, sch, &sch->q);
 628 }
 629
 630 static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
 631                                                    struct sk_buff_head *list)
 632 {
 633         struct sk_buff *skb = __skb_dequeue(list);
 634
 635         if (likely(skb != NULL)) {
 636                 qdisc_qstats_backlog_dec(sch, skb);
 637                 qdisc_bstats_update(sch, skb);
 638         }
 639
 640         return skb;
 641 }
 642
 643 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
 644 {
 645         return __qdisc_dequeue_head(sch, &sch->q);
 646 }
 647
 648 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
 649                                               struct sk_buff_head *list)
 650 {
 651         struct sk_buff *skb = __skb_dequeue(list);
 652
 653         if (likely(skb != NULL)) {
 654                 unsigned int len = qdisc_pkt_len(skb);
 655                 qdisc_qstats_backlog_dec(sch, skb);
 656                 kfree_skb(skb);
 657                 return len;
 658         }
 659
 660         return 0;
 661 }
 662
 663 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
 664 {
 665         return __qdisc_queue_drop_head(sch, &sch->q);
 666 }
 667
 668 static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
 669                                                    struct sk_buff_head *list)
 670 {
 671         struct sk_buff *skb = __skb_dequeue_tail(list);
 672
 673         if (likely(skb != NULL))
 674                 qdisc_qstats_backlog_dec(sch, skb);
 675
 676         return skb;
 677 }
 678
 679 static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
 680 {
 681         return __qdisc_dequeue_tail(sch, &sch->q);
 682 }
 683
 684 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
 685 {
 686         return skb_peek(&sch->q);
 687 }
 688
 689 /* generic pseudo peek method for non-work-conserving qdisc */
 690 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
 691 {
 692         /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
 693         if (!sch->gso_skb) {
 694                 sch->gso_skb = sch->dequeue(sch);
 695                 if (sch->gso_skb) {
 696                         /* it's still part of the queue */
 697                         qdisc_qstats_backlog_inc(sch, sch->gso_skb);
 698                         sch->q.qlen++;
 699                 }
 700         }
 701
 702         return sch->gso_skb;
 703 }
 704
 705 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
 706 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
 707 {
 708         struct sk_buff *skb = sch->gso_skb;
 709
 710         if (skb) {
 711                 sch->gso_skb = NULL;
 712                 qdisc_qstats_backlog_dec(sch, skb);
 713                 sch->q.qlen--;
 714         } else {
 715                 skb = sch->dequeue(sch);
 716         }
 717
 718         return skb;
 719 }
 720
 721 static inline void __qdisc_reset_queue(struct Qdisc *sch,
 722                                        struct sk_buff_head *list)
 723 {
 724         /*
 725          * We do not know the backlog in bytes of this list, it
 726          * is up to the caller to correct it
 727          */
 728         __skb_queue_purge(list);
 729 }
 730
 731 static inline void qdisc_reset_queue(struct Qdisc *sch)
 732 {
 733         __qdisc_reset_queue(sch, &sch->q);
 734         sch->qstats.backlog = 0;
 735 }
 736
 737 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
 738                                           struct Qdisc **pold)
 739 {
 740         struct Qdisc *old;
 741
 742         sch_tree_lock(sch);
 743         old = *pold;
 744         *pold = new;
 745         if (old != NULL) {
 746                 qdisc_tree_reduce_backlog(old, old->q.qlen, old->qstats.backlog);
 747                 qdisc_reset(old);
 748         }
 749         sch_tree_unlock(sch);
 750
 751         return old;
 752 }
 753
 754 static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
 755                                               struct sk_buff_head *list)
 756 {
 757         struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
 758
 759         if (likely(skb != NULL)) {
 760                 unsigned int len = qdisc_pkt_len(skb);
 761                 kfree_skb(skb);
 762                 return len;
 763         }
 764
 765         return 0;
 766 }
 767
 768 static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
 769 {
 770         return __qdisc_queue_drop(sch, &sch->q);
 771 }
 772
 773 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
 774 {
 775         kfree_skb(skb);
 776         qdisc_qstats_drop(sch);
 777
 778         return NET_XMIT_DROP;
 779 }
 780
 781 static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
 782 {
 783         qdisc_qstats_drop(sch);
 784
 785 #ifdef CONFIG_NET_CLS_ACT
 786         if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
 787                 goto drop;
 788
 789         return NET_XMIT_SUCCESS;
 790
 791 drop:
 792 #endif
 793         kfree_skb(skb);
 794         return NET_XMIT_DROP;
 795 }
 796
 797 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
 798    long it will take to send a packet given its size.
 799  */
 800 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
 801 {
 802         int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
 803         if (slot < 0)
 804                 slot = 0;
 805         slot >>= rtab->rate.cell_log;
 806         if (slot > 255)
 807                 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
 808         return rtab->data[slot];
 809 }
 810
 811 struct psched_ratecfg {
 812         u64     rate_bytes_ps; /* bytes per second */
 813         u32     mult;
 814         u16     overhead;
 815         u8      linklayer;
 816         u8      shift;
 817 };
 818
 819 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
 820                                 unsigned int len)
 821 {
 822         len += r->overhead;
 823
 824         if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
 825                 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
 826
 827         return ((u64)len * r->mult) >> r->shift;
 828 }
 829
 830 void psched_ratecfg_precompute(struct psched_ratecfg *r,
 831                                const struct tc_ratespec *conf,
 832                                u64 rate64);
 833
 834 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
 835                                           const struct psched_ratecfg *r)
 836 {
 837         memset(res, 0, sizeof(*res));
 838
 839         /* legacy struct tc_ratespec has a 32bit @rate field
 840          * Qdisc using 64bit rate should add new attributes
 841          * in order to maintain compatibility.
 842          */
 843         res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
 844
 845         res->overhead = r->overhead;
 846         res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
 847 }
 848
 849 #endif