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         u32                     limit;
  75         const struct Qdisc_ops  *ops;
  76         struct qdisc_size_table __rcu *stab;
  77         struct hlist_node       hash;
  78         u32                     handle;
  79         u32                     parent;
  80
  81         struct netdev_queue     *dev_queue;
  82
  83         struct net_rate_estimator __rcu *rate_est;
  84         struct gnet_stats_basic_cpu __percpu *cpu_bstats;
  85         struct gnet_stats_queue __percpu *cpu_qstats;
  86
  87         /*
  88          * For performance sake on SMP, we put highly modified fields at the end
  89          */
  90         struct sk_buff          *gso_skb ____cacheline_aligned_in_smp;
  91         struct qdisc_skb_head   q;
  92         struct gnet_stats_basic_packed bstats;
  93         seqcount_t              running;
  94         struct gnet_stats_queue qstats;
  95         unsigned long           state;
  96         struct Qdisc            *next_sched;
  97         struct sk_buff          *skb_bad_txq;
  98         struct rcu_head         rcu_head;
  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 *, unsigned long);
 166         unsigned long           (*bind_tcf)(struct Qdisc *, unsigned long,
 167                                         u32 classid);
 168         void                    (*unbind_tcf)(struct Qdisc *, unsigned long);
 169
 170         /* rtnetlink specific */
 171         int                     (*dump)(struct Qdisc *, unsigned long,
 172                                         struct sk_buff *skb, struct tcmsg*);
 173         int                     (*dump_stats)(struct Qdisc *, unsigned long,
 174                                         struct gnet_dump *);
 175 };
 176
 177 struct Qdisc_ops {
 178         struct Qdisc_ops        *next;
 179         const struct Qdisc_class_ops    *cl_ops;
 180         char                    id[IFNAMSIZ];
 181         int                     priv_size;
 182
 183         int                     (*enqueue)(struct sk_buff *skb,
 184                                            struct Qdisc *sch,
 185                                            struct sk_buff **to_free);
 186         struct sk_buff *        (*dequeue)(struct Qdisc *);
 187         struct sk_buff *        (*peek)(struct Qdisc *);
 188
 189         int                     (*init)(struct Qdisc *, struct nlattr *arg);
 190         void                    (*reset)(struct Qdisc *);
 191         void                    (*destroy)(struct Qdisc *);
 192         int                     (*change)(struct Qdisc *, struct nlattr *arg);
 193         void                    (*attach)(struct Qdisc *);
 194
 195         int                     (*dump)(struct Qdisc *, struct sk_buff *);
 196         int                     (*dump_stats)(struct Qdisc *, struct gnet_dump *);
 197
 198         struct module           *owner;
 199 };
 200
 201
 202 struct tcf_result {
 203         union {
 204                 struct {
 205                         unsigned long   class;
 206                         u32             classid;
 207                 };
 208                 const struct tcf_proto *goto_tp;
 209         };
 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         void                    (*destroy)(struct tcf_proto*);
 221
 222         void*                   (*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                                         void **, bool);
 227         int                     (*delete)(struct tcf_proto*, void *, bool*);
 228         void                    (*walk)(struct tcf_proto*, struct tcf_walker *arg);
 229         void                    (*bind_class)(void *, u32, unsigned long);
 230
 231         /* rtnetlink specific */
 232         int                     (*dump)(struct net*, struct tcf_proto*, void *,
 233                                         struct sk_buff *skb, struct tcmsg*);
 234
 235         struct module           *owner;
 236 };
 237
 238 struct tcf_proto {
 239         /* Fast access part */
 240         struct tcf_proto __rcu  *next;
 241         void __rcu              *root;
 242         int                     (*classify)(struct sk_buff *,
 243                                             const struct tcf_proto *,
 244                                             struct tcf_result *);
 245         __be16                  protocol;
 246
 247         /* All the rest */
 248         u32                     prio;
 249         u32                     classid;
 250         struct Qdisc            *q;
 251         void                    *data;
 252         const struct tcf_proto_ops      *ops;
 253         struct tcf_chain        *chain;
 254         struct rcu_head         rcu;
 255 };
 256
 257 struct qdisc_skb_cb {
 258         unsigned int            pkt_len;
 259         u16                     slave_dev_queue_mapping;
 260         u16                     tc_classid;
 261 #define QDISC_CB_PRIV_LEN 20
 262         unsigned char           data[QDISC_CB_PRIV_LEN];
 263 };
 264
 265 struct tcf_chain {
 266         struct tcf_proto __rcu *filter_chain;
 267         struct tcf_proto __rcu **p_filter_chain;
 268         struct list_head list;
 269         struct tcf_block *block;
 270         u32 index; /* chain index */
 271         unsigned int refcnt;
 272 };
 273
 274 struct tcf_block {
 275         struct list_head chain_list;
 276         struct work_struct work;
 277 };
 278
 279 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
 280 {
 281         struct qdisc_skb_cb *qcb;
 282
 283         BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
 284         BUILD_BUG_ON(sizeof(qcb->data) < sz);
 285 }
 286
 287 static inline int qdisc_qlen(const struct Qdisc *q)
 288 {
 289         return q->q.qlen;
 290 }
 291
 292 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
 293 {
 294         return (struct qdisc_skb_cb *)skb->cb;
 295 }
 296
 297 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
 298 {
 299         return &qdisc->q.lock;
 300 }
 301
 302 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
 303 {
 304         struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
 305
 306         return q;
 307 }
 308
 309 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
 310 {
 311         return qdisc->dev_queue->qdisc_sleeping;
 312 }
 313
 314 /* The qdisc root lock is a mechanism by which to top level
 315  * of a qdisc tree can be locked from any qdisc node in the
 316  * forest.  This allows changing the configuration of some
 317  * aspect of the qdisc tree while blocking out asynchronous
 318  * qdisc access in the packet processing paths.
 319  *
 320  * It is only legal to do this when the root will not change
 321  * on us.  Otherwise we'll potentially lock the wrong qdisc
 322  * root.  This is enforced by holding the RTNL semaphore, which
 323  * all users of this lock accessor must do.
 324  */
 325 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
 326 {
 327         struct Qdisc *root = qdisc_root(qdisc);
 328
 329         ASSERT_RTNL();
 330         return qdisc_lock(root);
 331 }
 332
 333 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
 334 {
 335         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 336
 337         ASSERT_RTNL();
 338         return qdisc_lock(root);
 339 }
 340
 341 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc)
 342 {
 343         struct Qdisc *root = qdisc_root_sleeping(qdisc);
 344
 345         ASSERT_RTNL();
 346         return &root->running;
 347 }
 348
 349 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
 350 {
 351         return qdisc->dev_queue->dev;
 352 }
 353
 354 static inline void sch_tree_lock(const struct Qdisc *q)
 355 {
 356         spin_lock_bh(qdisc_root_sleeping_lock(q));
 357 }
 358
 359 static inline void sch_tree_unlock(const struct Qdisc *q)
 360 {
 361         spin_unlock_bh(qdisc_root_sleeping_lock(q));
 362 }
 363
 364 #define tcf_tree_lock(tp)       sch_tree_lock((tp)->q)
 365 #define tcf_tree_unlock(tp)     sch_tree_unlock((tp)->q)
 366
 367 extern struct Qdisc noop_qdisc;
 368 extern struct Qdisc_ops noop_qdisc_ops;
 369 extern struct Qdisc_ops pfifo_fast_ops;
 370 extern struct Qdisc_ops mq_qdisc_ops;
 371 extern struct Qdisc_ops noqueue_qdisc_ops;
 372 extern const struct Qdisc_ops *default_qdisc_ops;
 373 static inline const struct Qdisc_ops *
 374 get_default_qdisc_ops(const struct net_device *dev, int ntx)
 375 {
 376         return ntx < dev->real_num_tx_queues ?
 377                         default_qdisc_ops : &pfifo_fast_ops;
 378 }
 379
 380 struct Qdisc_class_common {
 381         u32                     classid;
 382         struct hlist_node       hnode;
 383 };
 384
 385 struct Qdisc_class_hash {
 386         struct hlist_head       *hash;
 387         unsigned int            hashsize;
 388         unsigned int            hashmask;
 389         unsigned int            hashelems;
 390 };
 391
 392 static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
 393 {
 394         id ^= id >> 8;
 395         id ^= id >> 4;
 396         return id & mask;
 397 }
 398
 399 static inline struct Qdisc_class_common *
 400 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
 401 {
 402         struct Qdisc_class_common *cl;
 403         unsigned int h;
 404
 405         if (!id)
 406                 return NULL;
 407
 408         h = qdisc_class_hash(id, hash->hashmask);
 409         hlist_for_each_entry(cl, &hash->hash[h], hnode) {
 410                 if (cl->classid == id)
 411                         return cl;
 412         }
 413         return NULL;
 414 }
 415
 416 int qdisc_class_hash_init(struct Qdisc_class_hash *);
 417 void qdisc_class_hash_insert(struct Qdisc_class_hash *,
 418                              struct Qdisc_class_common *);
 419 void qdisc_class_hash_remove(struct Qdisc_class_hash *,
 420                              struct Qdisc_class_common *);
 421 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
 422 void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
 423
 424 void dev_init_scheduler(struct net_device *dev);
 425 void dev_shutdown(struct net_device *dev);
 426 void dev_activate(struct net_device *dev);
 427 void dev_deactivate(struct net_device *dev);
 428 void dev_deactivate_many(struct list_head *head);
 429 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 430                               struct Qdisc *qdisc);
 431 void qdisc_reset(struct Qdisc *qdisc);
 432 void qdisc_destroy(struct Qdisc *qdisc);
 433 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
 434                                unsigned int len);
 435 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 436                           const struct Qdisc_ops *ops);
 437 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
 438                                 const struct Qdisc_ops *ops, u32 parentid);
 439 void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 440                                const struct qdisc_size_table *stab);
 441 int skb_do_redirect(struct sk_buff *);
 442
 443 static inline void skb_reset_tc(struct sk_buff *skb)
 444 {
 445 #ifdef CONFIG_NET_CLS_ACT
 446         skb->tc_redirected = 0;
 447 #endif
 448 }
 449
 450 static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
 451 {
 452 #ifdef CONFIG_NET_CLS_ACT
 453         return skb->tc_at_ingress;
 454 #else
 455         return false;
 456 #endif
 457 }
 458
 459 static inline bool skb_skip_tc_classify(struct sk_buff *skb)
 460 {
 461 #ifdef CONFIG_NET_CLS_ACT
 462         if (skb->tc_skip_classify) {
 463                 skb->tc_skip_classify = 0;
 464                 return true;
 465         }
 466 #endif
 467         return false;
 468 }
 469
 470 /* Reset all TX qdiscs greater then index of a device.  */
 471 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
 472 {
 473         struct Qdisc *qdisc;
 474
 475         for (; i < dev->num_tx_queues; i++) {
 476                 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
 477                 if (qdisc) {
 478                         spin_lock_bh(qdisc_lock(qdisc));
 479                         qdisc_reset(qdisc);
 480                         spin_unlock_bh(qdisc_lock(qdisc));
 481                 }
 482         }
 483 }
 484
 485 static inline void qdisc_reset_all_tx(struct net_device *dev)
 486 {
 487         qdisc_reset_all_tx_gt(dev, 0);
 488 }
 489
 490 /* Are all TX queues of the device empty?  */
 491 static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 492 {
 493         unsigned int i;
 494
 495         rcu_read_lock();
 496         for (i = 0; i < dev->num_tx_queues; i++) {
 497                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 498                 const struct Qdisc *q = rcu_dereference(txq->qdisc);
 499
 500                 if (q->q.qlen) {
 501                         rcu_read_unlock();
 502                         return false;
 503                 }
 504         }
 505         rcu_read_unlock();
 506         return true;
 507 }
 508
 509 /* Are any of the TX qdiscs changing?  */
 510 static inline bool qdisc_tx_changing(const struct net_device *dev)
 511 {
 512         unsigned int i;
 513
 514         for (i = 0; i < dev->num_tx_queues; i++) {
 515                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 516                 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
 517                         return true;
 518         }
 519         return false;
 520 }
 521
 522 /* Is the device using the noop qdisc on all queues?  */
 523 static inline bool qdisc_tx_is_noop(const struct net_device *dev)
 524 {
 525         unsigned int i;
 526
 527         for (i = 0; i < dev->num_tx_queues; i++) {
 528                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 529                 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
 530                         return false;
 531         }
 532         return true;
 533 }
 534
 535 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
 536 {
 537         return qdisc_skb_cb(skb)->pkt_len;
 538 }
 539
 540 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
 541 enum net_xmit_qdisc_t {
 542         __NET_XMIT_STOLEN = 0x00010000,
 543         __NET_XMIT_BYPASS = 0x00020000,
 544 };
 545
 546 #ifdef CONFIG_NET_CLS_ACT
 547 #define net_xmit_drop_count(e)  ((e) & __NET_XMIT_STOLEN ? 0 : 1)
 548 #else
 549 #define net_xmit_drop_count(e)  (1)
 550 #endif
 551
 552 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
 553                                            const struct Qdisc *sch)
 554 {
 555 #ifdef CONFIG_NET_SCHED
 556         struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
 557
 558         if (stab)
 559                 __qdisc_calculate_pkt_len(skb, stab);
 560 #endif
 561 }
 562
 563 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 564                                 struct sk_buff **to_free)
 565 {
 566         qdisc_calculate_pkt_len(skb, sch);
 567         return sch->enqueue(skb, sch, to_free);
 568 }
 569
 570 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
 571 {
 572         return q->flags & TCQ_F_CPUSTATS;
 573 }
 574
 575 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats,
 576                                   __u64 bytes, __u32 packets)
 577 {
 578         bstats->bytes += bytes;
 579         bstats->packets += packets;
 580 }
 581
 582 static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
 583                                  const struct sk_buff *skb)
 584 {
 585         _bstats_update(bstats,
 586                        qdisc_pkt_len(skb),
 587                        skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1);
 588 }
 589
 590 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
 591                                       __u64 bytes, __u32 packets)
 592 {
 593         u64_stats_update_begin(&bstats->syncp);
 594         _bstats_update(&bstats->bstats, bytes, packets);
 595         u64_stats_update_end(&bstats->syncp);
 596 }
 597
 598 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats,
 599                                      const struct sk_buff *skb)
 600 {
 601         u64_stats_update_begin(&bstats->syncp);
 602         bstats_update(&bstats->bstats, skb);
 603         u64_stats_update_end(&bstats->syncp);
 604 }
 605
 606 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch,
 607                                            const struct sk_buff *skb)
 608 {
 609         bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb);
 610 }
 611
 612 static inline void qdisc_bstats_update(struct Qdisc *sch,
 613                                        const struct sk_buff *skb)
 614 {
 615         bstats_update(&sch->bstats, skb);
 616 }
 617
 618 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
 619                                             const struct sk_buff *skb)
 620 {
 621         sch->qstats.backlog -= qdisc_pkt_len(skb);
 622 }
 623
 624 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
 625                                             const struct sk_buff *skb)
 626 {
 627         sch->qstats.backlog += qdisc_pkt_len(skb);
 628 }
 629
 630 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
 631 {
 632         sch->qstats.drops += count;
 633 }
 634
 635 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats)
 636 {
 637         qstats->drops++;
 638 }
 639
 640 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats)
 641 {
 642         qstats->overlimits++;
 643 }
 644
 645 static inline void qdisc_qstats_drop(struct Qdisc *sch)
 646 {
 647         qstats_drop_inc(&sch->qstats);
 648 }
 649
 650 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch)
 651 {
 652         this_cpu_inc(sch->cpu_qstats->drops);
 653 }
 654
 655 static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
 656 {
 657         sch->qstats.overlimits++;
 658 }
 659
 660 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh)
 661 {
 662         qh->head = NULL;
 663         qh->tail = NULL;
 664         qh->qlen = 0;
 665 }
 666
 667 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
 668                                        struct qdisc_skb_head *qh)
 669 {
 670         struct sk_buff *last = qh->tail;
 671
 672         if (last) {
 673                 skb->next = NULL;
 674                 last->next = skb;
 675                 qh->tail = skb;
 676         } else {
 677                 qh->tail = skb;
 678                 qh->head = skb;
 679         }
 680         qh->qlen++;
 681         qdisc_qstats_backlog_inc(sch, skb);
 682
 683         return NET_XMIT_SUCCESS;
 684 }
 685
 686 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
 687 {
 688         return __qdisc_enqueue_tail(skb, sch, &sch->q);
 689 }
 690
 691 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh)
 692 {
 693         struct sk_buff *skb = qh->head;
 694
 695         if (likely(skb != NULL)) {
 696                 qh->head = skb->next;
 697                 qh->qlen--;
 698                 if (qh->head == NULL)
 699                         qh->tail = NULL;
 700                 skb->next = NULL;
 701         }
 702
 703         return skb;
 704 }
 705
 706 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
 707 {
 708         struct sk_buff *skb = __qdisc_dequeue_head(&sch->q);
 709
 710         if (likely(skb != NULL)) {
 711                 qdisc_qstats_backlog_dec(sch, skb);
 712                 qdisc_bstats_update(sch, skb);
 713         }
 714
 715         return skb;
 716 }
 717
 718 /* Instead of calling kfree_skb() while root qdisc lock is held,
 719  * queue the skb for future freeing at end of __dev_xmit_skb()
 720  */
 721 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free)
 722 {
 723         skb->next = *to_free;
 724         *to_free = skb;
 725 }
 726
 727 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
 728                                                    struct qdisc_skb_head *qh,
 729                                                    struct sk_buff **to_free)
 730 {
 731         struct sk_buff *skb = __qdisc_dequeue_head(qh);
 732
 733         if (likely(skb != NULL)) {
 734                 unsigned int len = qdisc_pkt_len(skb);
 735
 736                 qdisc_qstats_backlog_dec(sch, skb);
 737                 __qdisc_drop(skb, to_free);
 738                 return len;
 739         }
 740
 741         return 0;
 742 }
 743
 744 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch,
 745                                                  struct sk_buff **to_free)
 746 {
 747         return __qdisc_queue_drop_head(sch, &sch->q, to_free);
 748 }
 749
 750 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
 751 {
 752         const struct qdisc_skb_head *qh = &sch->q;
 753
 754         return qh->head;
 755 }
 756
 757 /* generic pseudo peek method for non-work-conserving qdisc */
 758 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
 759 {
 760         /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
 761         if (!sch->gso_skb) {
 762                 sch->gso_skb = sch->dequeue(sch);
 763                 if (sch->gso_skb) {
 764                         /* it's still part of the queue */
 765                         qdisc_qstats_backlog_inc(sch, sch->gso_skb);
 766                         sch->q.qlen++;
 767                 }
 768         }
 769
 770         return sch->gso_skb;
 771 }
 772
 773 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
 774 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
 775 {
 776         struct sk_buff *skb = sch->gso_skb;
 777
 778         if (skb) {
 779                 sch->gso_skb = NULL;
 780                 qdisc_qstats_backlog_dec(sch, skb);
 781                 sch->q.qlen--;
 782         } else {
 783                 skb = sch->dequeue(sch);
 784         }
 785
 786         return skb;
 787 }
 788
 789 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh)
 790 {
 791         /*
 792          * We do not know the backlog in bytes of this list, it
 793          * is up to the caller to correct it
 794          */
 795         ASSERT_RTNL();
 796         if (qh->qlen) {
 797                 rtnl_kfree_skbs(qh->head, qh->tail);
 798
 799                 qh->head = NULL;
 800                 qh->tail = NULL;
 801                 qh->qlen = 0;
 802         }
 803 }
 804
 805 static inline void qdisc_reset_queue(struct Qdisc *sch)
 806 {
 807         __qdisc_reset_queue(&sch->q);
 808         sch->qstats.backlog = 0;
 809 }
 810
 811 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new,
 812                                           struct Qdisc **pold)
 813 {
 814         struct Qdisc *old;
 815
 816         sch_tree_lock(sch);
 817         old = *pold;
 818         *pold = new;
 819         if (old != NULL) {
 820                 unsigned int qlen = old->q.qlen;
 821                 unsigned int backlog = old->qstats.backlog;
 822
 823                 qdisc_reset(old);
 824                 qdisc_tree_reduce_backlog(old, qlen, backlog);
 825         }
 826         sch_tree_unlock(sch);
 827
 828         return old;
 829 }
 830
 831 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
 832 {
 833         rtnl_kfree_skbs(skb, skb);
 834         qdisc_qstats_drop(sch);
 835 }
 836
 837
 838 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
 839                              struct sk_buff **to_free)
 840 {
 841         __qdisc_drop(skb, to_free);
 842         qdisc_qstats_drop(sch);
 843
 844         return NET_XMIT_DROP;
 845 }
 846
 847 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
 848    long it will take to send a packet given its size.
 849  */
 850 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
 851 {
 852         int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
 853         if (slot < 0)
 854                 slot = 0;
 855         slot >>= rtab->rate.cell_log;
 856         if (slot > 255)
 857                 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
 858         return rtab->data[slot];
 859 }
 860
 861 struct psched_ratecfg {
 862         u64     rate_bytes_ps; /* bytes per second */
 863         u32     mult;
 864         u16     overhead;
 865         u8      linklayer;
 866         u8      shift;
 867 };
 868
 869 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
 870                                 unsigned int len)
 871 {
 872         len += r->overhead;
 873
 874         if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
 875                 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
 876
 877         return ((u64)len * r->mult) >> r->shift;
 878 }
 879
 880 void psched_ratecfg_precompute(struct psched_ratecfg *r,
 881                                const struct tc_ratespec *conf,
 882                                u64 rate64);
 883
 884 static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
 885                                           const struct psched_ratecfg *r)
 886 {
 887         memset(res, 0, sizeof(*res));
 888
 889         /* legacy struct tc_ratespec has a 32bit @rate field
 890          * Qdisc using 64bit rate should add new attributes
 891          * in order to maintain compatibility.
 892          */
 893         res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
 894
 895         res->overhead = r->overhead;
 896         res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
 897 }
 898
 899 #endif