include/net/sch_generic.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __NET_SCHED_GENERIC_H
   3 #define __NET_SCHED_GENERIC_H
   4
   5 #include <linux/netdevice.h>
   6 #include <linux/types.h>
   7 #include <linux/rcupdate.h>
   8 #include <linux/pkt_sched.h>
   9 #include <linux/pkt_cls.h>
  10 #include <linux/percpu.h>
  11 #include <linux/dynamic_queue_limits.h>
  12 #include <linux/list.h>
  13 #include <linux/refcount.h>
  14 #include <linux/workqueue.h>
  15 #include <net/gen_stats.h>
  16 #include <net/rtnetlink.h>
  17
  18 struct Qdisc_ops;
  19 struct qdisc_walker;
  20 struct tcf_walker;
  21 struct module;
  22
  23 struct qdisc_rate_table {
  24         struct tc_ratespec rate;
  25         u32             data[256];
  26         struct qdisc_rate_table *next;
  27         int             refcnt;
  28 };
  29
  30 enum qdisc_state_t {
  31         __QDISC_STATE_SCHED,
  32         __QDISC_STATE_DEACTIVATED,
  33 };
  34
  35 struct qdisc_size_table {
  36         struct rcu_head         rcu;
  37         struct list_head        list;
  38         struct tc_sizespec      szopts;
  39         int                     refcnt;
  40         u16                     data[];
  41 };
  42
  43 /* similar to sk_buff_head, but skb->prev pointer is undefined. */
  44 struct qdisc_skb_head {
  45         struct sk_buff  *head;
  46         struct sk_buff  *tail;
  47         __u32           qlen;
  48         spinlock_t      lock;
  49 };
  50
  51 struct Qdisc {
  52         int                     (*enqueue)(struct sk_buff *skb,
  53                                            struct Qdisc *sch,
  54                                            struct sk_buff **to_free);
  55         struct sk_buff *        (*dequeue)(struct Qdisc *sch);
  56         unsigned int            flags;
  57 #define TCQ_F_BUILTIN           1
  58 #define TCQ_F_INGRESS           2
  59 #define TCQ_F_CAN_BYPASS        4
  60 #define TCQ_F_MQROOT            8
  61 #define TCQ_F_ONETXQUEUE        0x10 /* dequeue_skb() can assume all skbs are for
  62                                       * q->dev_queue : It can test
  63                                       * netif_xmit_frozen_or_stopped() before
  64                                       * dequeueing next packet.
  65                                       * Its true for MQ/MQPRIO slaves, or non
  66                                       * multiqueue device.
  67                                       */
  68 #define TCQ_F_WARN_NONWC        (1 << 16)
  69 #define TCQ_F_CPUSTATS          0x20 /* run using percpu statistics */
  70 #define TCQ_F_NOPARENT          0x40 /* root of its hierarchy :
  71                                       * qdisc_tree_decrease_qlen() should stop.
  72                                       */
  73 #define TCQ_F_INVISIBLE         0x80 /* invisible by default in dump */
  74 #define TCQ_F_NOLOCK            0x100 /* qdisc does not require locking */
  75         u32                     limit;
  76         const struct Qdisc_ops  *ops;
  77         struct qdisc_size_table __rcu *stab;
  78         struct hlist_node       hash;
  79         u32                     handle;
  80         u32                     parent;
  81
  82         struct netdev_queue     *dev_queue;
  83
  84         struct net_rate_estimator __rcu *rate_est;
  85         struct gnet_stats_basic_cpu __percpu *cpu_bstats;
  86         struct gnet_stats_queue __percpu *cpu_qstats;
  87
  88         /*
  89          * For performance sake on SMP, we put highly modified fields at the end
  90          */
  91         struct sk_buff_head     gso_skb ____cacheline_aligned_in_smp;
  92         struct qdisc_skb_head   q;
  93         struct gnet_stats_basic_packed bstats;
  94         seqcount_t              running;
  95         struct gnet_stats_queue qstats;
  96         unsigned long           state;
  97         struct Qdisc            *next_sched;
  98         struct sk_buff          *skb_bad_txq;
  99         int                     padded;
 100         refcount_t              refcnt;
 101
 102         spinlock_t              busylock ____cacheline_aligned_in_smp;
 103 };
 104
 105 static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
 106 {
 107         if (qdisc->flags & TCQ_F_BUILTIN)
 108                 return;
 109         refcount_inc(&qdisc->refcnt);
 110 }
 111
 112 static inline bool qdisc_is_running(const struct Qdisc *qdisc)
 113 {
 114         return (raw_read_seqcount(&qdisc->running) & 1) ? true : false;
 115 }
 116
 117 static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 118 {
 119         if (qdisc_is_running(qdisc))
 120                 return false;
 121         /* Variant of write_seqcount_begin() telling lockdep a trylock
 122          * was attempted.
 123          */
 124         raw_write_seqcount_begin(&qdisc->running);
 125         seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_);
 126         return true;
 127 }
 128
 129 static inline void qdisc_run_end(struct Qdisc *qdisc)
 130 {
 131         write_seqcount_end(&qdisc->running);
 132 }
 133
 134 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
 135 {
 136         return qdisc->flags & TCQ_F_ONETXQUEUE;
 137 }
 138
 139 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
 140 {
 141 #ifdef CONFIG_BQL
 142         /* Non-BQL migrated drivers will return 0, too. */
 143         return dql_avail(&txq->dql);
 144 #else
 145         return 0;
 146 #endif
 147 }
 148
 149 struct Qdisc_class_ops {
 150         /* Child qdisc manipulation */
 151         struct netdev_queue *   (*select_queue)(struct Qdisc *, struct tcmsg *);
 152         int                     (*graft)(struct Qdisc *, unsigned long cl,
 153                                         struct Qdisc *, struct Qdisc **);
 154         struct Qdisc *          (*leaf)(struct Qdisc *, unsigned long cl);
 155         void                    (*qlen_notify)(struct Qdisc *, unsigned long);
 156
 157         /* Class manipulation routines */
 158         unsigned long           (*find)(struct Qdisc *, u32 classid);
 159         int                     (*change)(struct Qdisc *, u32, u32,
 160                                         struct nlattr **, unsigned long *);
 161         int                     (*delete)(struct Qdisc *, unsigned long);
 162         void                    (*walk)(struct Qdisc *, struct qdisc_walker * arg);
 163
 164         /* Filter manipulation */
 165         struct tcf_block *      (*tcf_block)(struct Qdisc *sch,
 166                                              unsigned long arg);
 167         unsigned long           (*bind_tcf)(struct Qdisc *, unsigned long,
 168                                         u32 classid);
 169         void                    (*unbind_tcf)(struct Qdisc *, unsigned long);
 170
 171         /* rtnetlink specific */
 172         int                     (*dump)(struct Qdisc *, unsigned long,
 173                                         struct sk_buff *skb, struct tcmsg*);
 174         int                     (*dump_stats)(struct Qdisc *, unsigned long,
 175                                         struct gnet_dump *);
 176 };
 177
 178 struct Qdisc_ops {
 179         struct Qdisc_ops        *next;
 180         const struct Qdisc_class_ops    *cl_ops;
 181         char                    id[IFNAMSIZ];
 182         int                     priv_size;
 183         unsigned int            static_flags;
 184
 185         int                     (*enqueue)(struct sk_buff *skb,
 186                                            struct Qdisc *sch,
 187                                            struct sk_buff **to_free);
 188         struct sk_buff *        (*dequeue)(struct Qdisc *);
 189         struct sk_buff *        (*peek)(struct Qdisc *);
 190
 191         int                     (*init)(struct Qdisc *sch, struct nlattr *arg);
 192         void                    (*reset)(struct Qdisc *);
 193         void                    (*destroy)(struct Qdisc *);
 194         int                     (*change)(struct Qdisc *sch,
 195                                           struct nlattr *arg);
 196         void                    (*attach)(struct Qdisc *sch);
 197
 198         int                     (*dump)(struct Qdisc *, struct sk_buff *);
 199         int                     (*dump_stats)(struct Qdisc *, struct gnet_dump *);
 200
 201         struct module           *owner;
 202 };
 203
 204
 205 struct tcf_result {
 206         union {
 207                 struct {
 208                         unsigned long   class;
 209                         u32             classid;
 210                 };
 211                 const struct tcf_proto *goto_tp;
 212         };
 213 };
 214
 215 struct tcf_proto_ops {
 216         struct list_head        head;
 217         char                    kind[IFNAMSIZ];
 218
 219         int                     (*classify)(struct sk_buff *,
 220                                             const struct tcf_proto *,
 221                                             struct tcf_result *);
 222         int                     (*init)(struct tcf_proto*);
 223         void                    (*destroy)(struct tcf_proto*);
 224
 225         void*                   (*get)(struct tcf_proto*, u32 handle);
 226         int                     (*change)(struct net *net, struct sk_buff *,
 227                                         struct tcf_proto*, unsigned long,
 228                                         u32 handle, struct nlattr **,
 229                                         void **, bool);
 230         int                     (*delete)(struct tcf_proto*, void *, bool*);
 231         void                    (*walk)(struct tcf_proto*, struct tcf_walker *arg);
 232         void                    (*bind_class)(void *, u32, unsigned long);
 233
 234         /* rtnetlink specific */
 235         int                     (*dump)(struct net*, struct tcf_proto*, void *,
 236                                         struct sk_buff *skb, struct tcmsg*);
 237
 238         struct module           *owner;
 239 };
 240
 241 struct tcf_proto {
 242         /* Fast access part */
 243         struct tcf_proto __rcu  *next;
 244         void __rcu              *root;
 245         int                     (*classify)(struct sk_buff *,
 246                                             const struct tcf_proto *,
 247                                             struct tcf_result *);
 248         __be16                  protocol;
 249
 250         /* All the rest */
 251         u32                     prio;
 252         u32                     classid;
 253         struct Qdisc            *q;
 254         void                    *data;
 255         const struct tcf_proto_ops      *ops;
 256         struct tcf_chain        *chain;
 257         struct rcu_head         rcu;
 258 };
 259
 260 struct qdisc_skb_cb {
 261         unsigned int            pkt_len;
 262         u16                     slave_dev_queue_mapping;
 263         u16                     tc_classid;
 264 #define QDISC_CB_PRIV_LEN 20
 265         unsigned char           data[QDISC_CB_PRIV_LEN];
 266 };
 267
 268 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv);
 269
 270 struct tcf_chain {
 271         struct tcf_proto __rcu *filter_chain;
 272         tcf_chain_head_change_t *chain_head_change;
 273         void *chain_head_change_priv;
 274         struct list_head list;
 275         struct tcf_block *block;
 276         u32 index; /* chain index */
 277         unsigned int refcnt;
 278 };
 279
 280 struct tcf_block {
 281         struct list_head chain_list;
 282         struct net *net;
 283         struct Qdisc *q;
 284         struct list_head cb_list;
 285 };
 286
 287 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
 288 {
 289         struct qdisc_skb_cb *qcb;
 290
 291         BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
 292         BUILD_BUG_ON(sizeof(qcb->data) < sz);
 293 }
 294
 295 static inline int qdisc_qlen(const struct Qdisc *q)
 296 {
 297         return q->q.qlen;
 298 }
 299
 300 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
 301 {
 302         return (struct qdisc_skb_cb *)skb->cb;
 303 }
 304
 305 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
 306 {
 307         return &qdisc->q.lock;
 308 }
 309
 310 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
 311 {
 312         struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
 313
 314         return q;
 315 }
 316
 317 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
 318 {
 319         return qdisc->dev_queue->qdisc_sleeping;
 320 }
 321
 322 /* The qdisc root lock is a mechanism by which to top level
 323  * of a qdisc tree can be locked from any qdisc node in the
 324  * forest.  This allows changing the configuration of some
 325  * aspect of the qdisc tree while blocking out asynchronous
 326  * qdisc access in the packet processing paths.
 327  *
 328  * It is only legal to do this when the root will not change
 329  * on us.  Otherwise we'll potentially lock the wrong qdisc
 330  * root.  This is enforced by holding the RTNL semaphore, which
 331  * all users of this lock accessor must do.
 332  */
 333 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
 334 {
 335         struct Qdisc *root = qdisc_root(qdisc);
 336
 337         ASSERT_RTNL();
 338         return qdisc_lock(root);
 339 }
 340
 341 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
 342 {
 343         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 344
 345         ASSERT_RTNL();
 346         return qdisc_lock(root);
 347 }
 348
 349 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
 350 {
 351         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 352
 353         ASSERT_RTNL();
 354         return &root->running;
 355 }
 356
 357 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
 358 {
 359         return qdisc->dev_queue->dev;
 360 }
 361
 362 static inline void sch_tree_lock(const struct Qdisc *q)
 363 {
 364         spin_lock_bh(qdisc_root_sleeping_lock(q));
 365 }
 366
 367 static inline void sch_tree_unlock(const struct Qdisc *q)
 368 {
 369         spin_unlock_bh(qdisc_root_sleeping_lock(q));
 370 }
 371
 372 extern struct Qdisc noop_qdisc;
 373 extern struct Qdisc_ops noop_qdisc_ops;
 374 extern struct Qdisc_ops pfifo_fast_ops;
 375 extern struct Qdisc_ops mq_qdisc_ops;
 376 extern struct Qdisc_ops noqueue_qdisc_ops;
 377 extern const struct Qdisc_ops *default_qdisc_ops;
 378 static inline const struct Qdisc_ops *
 379 get_default_qdisc_ops(const struct net_device *dev, int ntx)
 380 {
 381         return ntx < dev->real_num_tx_queues ?
 382                         default_qdisc_ops : &pfifo_fast_ops;
 383 }
 384
 385 struct Qdisc_class_common {
 386         u32                     classid;
 387         struct hlist_node       hnode;
 388 };
 389
 390 struct Qdisc_class_hash {
 391         struct hlist_head       *hash;
 392         unsigned int            hashsize;
 393         unsigned int            hashmask;
 394         unsigned int            hashelems;
 395 };
 396
 397 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
 398 {
 399         id ^= id >> 8;
 400         id ^= id >> 4;
 401         return id & mask;
 402 }
 403
 404 static inline struct Qdisc_class_common *
 405 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
 406 {
 407         struct Qdisc_class_common *cl;
 408         unsigned int h;
 409
 410         if (!id)
 411                 return NULL;
 412
 413         h = qdisc_class_hash(id, hash->hashmask);
 414         hlist_for_each_entry(cl, &hash->hash[h], hnode) {
 415                 if (cl->classid == id)
 416                         return cl;
 417         }
 418         return NULL;
 419 }
 420
 421 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid)
 422 {
 423         u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY;
 424
 425         return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL;
 426 }
 427
 428 int qdisc_class_hash_init(struct Qdisc_class_hash *);
 429 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
 430                              struct Qdisc_class_common *);
 431 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
 432                              struct Qdisc_class_common *);
 433 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
 434 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
 435
 436 void dev_init_scheduler(struct net_device *dev);
 437 void dev_shutdown(struct net_device *dev);
 438 void dev_activate(struct net_device *dev);
 439 void dev_deactivate(struct net_device *dev);
 440 void dev_deactivate_many(struct list_head *head);
 441 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 442                               struct Qdisc *qdisc);
 443 void qdisc_reset(struct Qdisc *qdisc);
 444 void qdisc_destroy(struct Qdisc *qdisc);
 445 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
 446                                unsigned int len);
 447 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 448                           const struct Qdisc_ops *ops);
 449 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
 450                                 const struct Qdisc_ops *ops, u32 parentid);
 451 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 452                                const struct qdisc_size_table *stab);
 453 int skb_do_redirect(struct sk_buff *);
 454
 455 static inline void skb_reset_tc(struct sk_buff *skb)
 456 {
 457 #ifdef CONFIG_NET_CLS_ACT
 458         skb->tc_redirected = 0;
 459 #endif
 460 }
 461
 462 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
 463 {
 464 #ifdef CONFIG_NET_CLS_ACT
 465         return skb->tc_at_ingress;
 466 #else
 467         return false;
 468 #endif
 469 }
 470
 471 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
 472 {
 473 #ifdef CONFIG_NET_CLS_ACT
 474         if (skb->tc_skip_classify) {
 475                 skb->tc_skip_classify = 0;
 476                 return true;
 477         }
 478 #endif
 479         return false;
 480 }
 481
 482 /* Reset all TX qdiscs greater then index of a device.  */
 483 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
 484 {
 485         struct Qdisc *qdisc;
 486
 487         for (; i < dev->num_tx_queues; i++) {
 488                 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
 489                 if (qdisc) {
 490                         spin_lock_bh(qdisc_lock(qdisc));
 491                         qdisc_reset(qdisc);
 492                         spin_unlock_bh(qdisc_lock(qdisc));
 493                 }
 494         }
 495 }
 496
 497 static inline void qdisc_reset_all_tx(struct net_device *dev)
 498 {
 499         qdisc_reset_all_tx_gt(dev, 0);
 500 }
 501
 502 /* Are all TX queues of the device empty?  */
 503 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 504 {
 505         unsigned int i;
 506
 507         rcu_read_lock();
 508         for (i = 0; i < dev->num_tx_queues; i++) {
 509                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 510                 const struct Qdisc *q = rcu_dereference(txq->qdisc);
 511
 512                 if (q->q.qlen) {
 513                         rcu_read_unlock();
 514                         return false;
 515                 }
 516         }
 517         rcu_read_unlock();
 518         return true;
 519 }
 520
 521 /* Are any of the TX qdiscs changing?  */
 522 static inline bool qdisc_tx_changing(const struct net_device *dev)
 523 {
 524         unsigned int i;
 525
 526         for (i = 0; i < dev->num_tx_queues; i++) {
 527                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 528                 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
 529                         return true;
 530         }
 531         return false;
 532 }
 533
 534 /* Is the device using the noop qdisc on all queues?  */
 535 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
 536 {
 537         unsigned int i;
 538
 539         for (i = 0; i < dev->num_tx_queues; i++) {
 540                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 541                 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
 542                         return false;
 543         }
 544         return true;
 545 }
 546
 547 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
 548 {
 549         return qdisc_skb_cb(skb)->pkt_len;
 550 }
 551
 552 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
 553 enum net_xmit_qdisc_t {
 554         __NET_XMIT_STOLEN = 0x00010000,
 555         __NET_XMIT_BYPASS = 0x00020000,
 556 };
 557
 558 #ifdef CONFIG_NET_CLS_ACT
 559 #define net_xmit_drop_count(e)  ((e) & __NET_XMIT_STOLEN ? 0 : 1)
 560 #else
 561 #define net_xmit_drop_count(e)  (1)
 562 #endif
 563
 564 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
 565                                            const struct Qdisc *sch)
 566 {
 567 #ifdef CONFIG_NET_SCHED
 568         struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
 569
 570         if (stab)
 571                 __qdisc_calculate_pkt_len(skb, stab);
 572 #endif
 573 }
 574
 575 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 576                                 struct sk_buff **to_free)
 577 {
 578         qdisc_calculate_pkt_len(skb, sch);
 579         return sch->enqueue(skb, sch, to_free);
 580 }
 581
 582 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
 583 {
 584         return q->flags & TCQ_F_CPUSTATS;
 585 }
 586
 587 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
 588                                   __u64 bytes, __u32 packets)
 589 {
 590         bstats->bytes += bytes;
 591         bstats->packets += packets;
 592 }
 593
 594 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
 595                                  const struct sk_buff *skb)
 596 {
 597         _bstats_update(bstats,
 598                        qdisc_pkt_len(skb),
 599                        skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
 600 }
 601
 602 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
 603                                       __u64 bytes, __u32 packets)
 604 {
 605         u64_stats_update_begin(&bstats->syncp);
 606         _bstats_update(&bstats->bstats, bytes, packets);
 607         u64_stats_update_end(&bstats->syncp);
 608 }
 609
 610 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
 611                                      const struct sk_buff *skb)
 612 {
 613         u64_stats_update_begin(&bstats->syncp);
 614         bstats_update(&bstats->bstats, skb);
 615         u64_stats_update_end(&bstats->syncp);
 616 }
 617
 618 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
 619                                            const struct sk_buff *skb)
 620 {
 621         bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
 622 }
 623
 624 static inline void qdisc_bstats_update(struct Qdisc *sch,
 625                                        const struct sk_buff *skb)
 626 {
 627         bstats_update(&sch->bstats, skb);
 628 }
 629
 630 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
 631                                             const struct sk_buff *skb)
 632 {
 633         sch->qstats.backlog -= qdisc_pkt_len(skb);
 634 }
 635
 636 static inline void qdisc_qstats_cpu_backlog_dec(struct Qdisc *sch,
 637                                                 const struct sk_buff *skb)
 638 {
 639         this_cpu_sub(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
 640 }
 641
 642 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
 643                                             const struct sk_buff *skb)
 644 {
 645         sch->qstats.backlog += qdisc_pkt_len(skb);
 646 }
 647
 648 static inline void qdisc_qstats_cpu_backlog_inc(struct Qdisc *sch,
 649                                                 const struct sk_buff *skb)
 650 {
 651         this_cpu_add(sch->cpu_qstats->backlog, qdisc_pkt_len(skb));
 652 }
 653
 654 static inline void qdisc_qstats_cpu_qlen_inc(struct Qdisc *sch)
 655 {
 656         this_cpu_inc(sch->cpu_qstats->qlen);
 657 }
 658
 659 static inline void qdisc_qstats_cpu_qlen_dec(struct Qdisc *sch)
 660 {
 661         this_cpu_dec(sch->cpu_qstats->qlen);
 662 }
 663
 664 static inline void qdisc_qstats_cpu_requeues_inc(struct Qdisc *sch)
 665 {
 666         this_cpu_inc(sch->cpu_qstats->requeues);
 667 }
 668
 669 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
 670 {
 671         sch->qstats.drops += count;
 672 }
 673
 674 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
 675 {
 676         qstats->drops++;
 677 }
 678
 679 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
 680 {
 681         qstats->overlimits++;
 682 }
 683
 684 static inline void qdisc_qstats_drop(struct Qdisc *sch)
 685 {
 686         qstats_drop_inc(&sch->qstats);
 687 }
 688
 689 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
 690 {
 691         this_cpu_inc(sch->cpu_qstats->drops);
 692 }
 693
 694 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
 695 {
 696         sch->qstats.overlimits++;
 697 }
 698
 699 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
 700 {
 701         qh->head = NULL;
 702         qh->tail = NULL;
 703         qh->qlen = 0;
 704 }
 705
 706 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
 707                                        struct qdisc_skb_head *qh)
 708 {
 709         struct sk_buff *last = qh->tail;
 710
 711         if (last) {
 712                 skb->next = NULL;
 713                 last->next = skb;
 714                 qh->tail = skb;
 715         } else {
 716                 qh->tail = skb;
 717                 qh->head = skb;
 718         }
 719         qh->qlen++;
 720         qdisc_qstats_backlog_inc(sch, skb);
 721
 722         return NET_XMIT_SUCCESS;
 723 }
 724
 725 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
 726 {
 727         return __qdisc_enqueue_tail(skb, sch, &sch->q);
 728 }
 729
 730 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
 731 {
 732         struct sk_buff *skb = qh->head;
 733
 734         if (likely(skb != NULL)) {
 735                 qh->head = skb->next;
 736                 qh->qlen--;
 737                 if (qh->head == NULL)
 738                         qh->tail = NULL;
 739                 skb->next = NULL;
 740         }
 741
 742         return skb;
 743 }
 744
 745 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
 746 {
 747         struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
 748
 749         if (likely(skb != NULL)) {
 750                 qdisc_qstats_backlog_dec(sch, skb);
 751                 qdisc_bstats_update(sch, skb);
 752         }
 753
 754         return skb;
 755 }
 756
 757 /* Instead of calling kfree_skb() while root qdisc lock is held,
 758  * queue the skb for future freeing at end of __dev_xmit_skb()
 759  */
 760 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
 761 {
 762         skb->next = *to_free;
 763         *to_free = skb;
 764 }
 765
 766 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
 767                                                    struct qdisc_skb_head *qh,
 768                                                    struct sk_buff **to_free)
 769 {
 770         struct sk_buff *skb = __qdisc_dequeue_head(qh);
 771
 772         if (likely(skb != NULL)) {
 773                 unsigned int len = qdisc_pkt_len(skb);
 774
 775                 qdisc_qstats_backlog_dec(sch, skb);
 776                 __qdisc_drop(skb, to_free);
 777                 return len;
 778         }
 779
 780         return 0;
 781 }
 782
 783 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
 784                                                  struct sk_buff **to_free)
 785 {
 786         return __qdisc_queue_drop_head(sch, &sch->q, to_free);
 787 }
 788
 789 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
 790 {
 791         const struct qdisc_skb_head *qh = &sch->q;
 792
 793         return qh->head;
 794 }
 795
 796 /* generic pseudo peek method for non-work-conserving qdisc */
 797 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
 798 {
 799         struct sk_buff *skb = skb_peek(&sch->gso_skb);
 800
 801         /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
 802         if (!skb) {
 803                 skb = sch->dequeue(sch);
 804
 805                 if (skb) {
 806                         __skb_queue_head(&sch->gso_skb, skb);
 807                         /* it's still part of the queue */
 808                         qdisc_qstats_backlog_inc(sch, skb);
 809                         sch->q.qlen++;
 810                 }
 811         }
 812
 813         return skb;
 814 }
 815
 816 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
 817 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
 818 {
 819         struct sk_buff *skb = skb_peek(&sch->gso_skb);
 820
 821         if (skb) {
 822                 skb = __skb_dequeue(&sch->gso_skb);
 823                 qdisc_qstats_backlog_dec(sch, skb);
 824                 sch->q.qlen--;
 825         } else {
 826                 skb = sch->dequeue(sch);
 827         }
 828
 829         return skb;
 830 }
 831
 832 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
 833 {
 834         /*
 835          * We do not know the backlog in bytes of this list, it
 836          * is up to the caller to correct it
 837          */
 838         ASSERT_RTNL();
 839         if (qh->qlen) {
 840                 rtnl_kfree_skbs(qh->head, qh->tail);
 841
 842                 qh->head = NULL;
 843                 qh->tail = NULL;
 844                 qh->qlen = 0;
 845         }
 846 }
 847
 848 static inline void qdisc_reset_queue(struct Qdisc *sch)
 849 {
 850         __qdisc_reset_queue(&sch->q);
 851         sch->qstats.backlog = 0;
 852 }
 853
 854 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
 855                                           struct Qdisc **pold)
 856 {
 857         struct Qdisc *old;
 858
 859         sch_tree_lock(sch);
 860         old = *pold;
 861         *pold = new;
 862         if (old != NULL) {
 863                 unsigned int qlen = old->q.qlen;
 864                 unsigned int backlog = old->qstats.backlog;
 865
 866                 qdisc_reset(old);
 867                 qdisc_tree_reduce_backlog(old, qlen, backlog);
 868         }
 869         sch_tree_unlock(sch);
 870
 871         return old;
 872 }
 873
 874 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
 875 {
 876         rtnl_kfree_skbs(skb, skb);
 877         qdisc_qstats_drop(sch);
 878 }
 879
 880 static inline int qdisc_drop_cpu(struct sk_buff *skb, struct Qdisc *sch,
 881                                  struct sk_buff **to_free)
 882 {
 883         __qdisc_drop(skb, to_free);
 884         qdisc_qstats_cpu_drop(sch);
 885
 886         return NET_XMIT_DROP;
 887 }
 888
 889 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
 890                              struct sk_buff **to_free)
 891 {
 892         __qdisc_drop(skb, to_free);
 893         qdisc_qstats_drop(sch);
 894
 895         return NET_XMIT_DROP;
 896 }
 897
 898 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
 899    long it will take to send a packet given its size.
 900  */
 901 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
 902 {
 903         int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
 904         if (slot < 0)
 905                 slot = 0;
 906         slot >>= rtab->rate.cell_log;
 907         if (slot > 255)
 908                 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
 909         return rtab->data[slot];
 910 }
 911
 912 struct psched_ratecfg {
 913         u64     rate_bytes_ps; /* bytes per second */
 914         u32     mult;
 915         u16     overhead;
 916         u8      linklayer;
 917         u8      shift;
 918 };
 919
 920 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
 921                                 unsigned int len)
 922 {
 923         len += r->overhead;
 924
 925         if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
 926                 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
 927
 928         return ((u64)len * r->mult) >> r->shift;
 929 }
 930
 931 void psched_ratecfg_precompute(struct psched_ratecfg *r,
 932                                const struct tc_ratespec *conf,
 933                                u64 rate64);
 934
 935 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
 936                                           const struct psched_ratecfg *r)
 937 {
 938         memset(res, 0, sizeof(*res));
 939
 940         /* legacy struct tc_ratespec has a 32bit @rate field
 941          * Qdisc using 64bit rate should add new attributes
 942          * in order to maintain compatibility.
 943          */
 944         res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
 945
 946         res->overhead = r->overhead;
 947         res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
 948 }
 949
 950 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc.
 951  * The fast path only needs to access filter list and to update stats
 952  */
 953 struct mini_Qdisc {
 954         struct tcf_proto *filter_list;
 955         struct gnet_stats_basic_cpu __percpu *cpu_bstats;
 956         struct gnet_stats_queue __percpu *cpu_qstats;
 957         struct rcu_head rcu;
 958 };
 959
 960 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq,
 961                                                 const struct sk_buff *skb)
 962 {
 963         bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb);
 964 }
 965
 966 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq)
 967 {
 968         this_cpu_inc(miniq->cpu_qstats->drops);
 969 }
 970
 971 struct mini_Qdisc_pair {
 972         struct mini_Qdisc miniq1;
 973         struct mini_Qdisc miniq2;
 974         struct mini_Qdisc __rcu **p_miniq;
 975 };
 976
 977 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp,
 978                           struct tcf_proto *tp_head);
 979 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc,
 980                           struct mini_Qdisc __rcu **p_miniq);
 981
 982 #endif