linux/include/net/sch_generic.h
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   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
  14struct Qdisc_ops;
  15struct qdisc_walker;
  16struct tcf_walker;
  17struct module;
  18
  19struct qdisc_rate_table {
  20        struct tc_ratespec rate;
  21        u32             data[256];
  22        struct qdisc_rate_table *next;
  23        int             refcnt;
  24};
  25
  26enum 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 */
  35enum qdisc___state_t {
  36        __QDISC___STATE_RUNNING = 1,
  37};
  38
  39struct 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
  47struct 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        u32                     limit;
  65        const struct Qdisc_ops  *ops;
  66        struct qdisc_size_table __rcu *stab;
  67        struct list_head        list;
  68        u32                     handle;
  69        u32                     parent;
  70        int                     (*reshape_fail)(struct sk_buff *skb,
  71                                        struct Qdisc *q);
  72
  73        void                    *u32_node;
  74
  75        /* This field is deprecated, but it is still used by CBQ
  76         * and it will live until better solution will be invented.
  77         */
  78        struct Qdisc            *__parent;
  79        struct netdev_queue     *dev_queue;
  80
  81        struct gnet_stats_rate_est64    rate_est;
  82        struct gnet_stats_basic_cpu __percpu *cpu_bstats;
  83        struct gnet_stats_queue __percpu *cpu_qstats;
  84
  85        struct Qdisc            *next_sched;
  86        struct sk_buff          *gso_skb;
  87        /*
  88         * For performance sake on SMP, we put highly modified fields at the end
  89         */
  90        unsigned long           state;
  91        struct sk_buff_head     q;
  92        struct gnet_stats_basic_packed bstats;
  93        unsigned int            __state;
  94        struct gnet_stats_queue qstats;
  95        struct rcu_head         rcu_head;
  96        int                     padded;
  97        atomic_t                refcnt;
  98
  99        spinlock_t              busylock ____cacheline_aligned_in_smp;
 100};
 101
 102static inline bool qdisc_is_running(const struct Qdisc *qdisc)
 103{
 104        return (qdisc->__state & __QDISC___STATE_RUNNING) ? true : false;
 105}
 106
 107static inline bool qdisc_run_begin(struct Qdisc *qdisc)
 108{
 109        if (qdisc_is_running(qdisc))
 110                return false;
 111        qdisc->__state |= __QDISC___STATE_RUNNING;
 112        return true;
 113}
 114
 115static inline void qdisc_run_end(struct Qdisc *qdisc)
 116{
 117        qdisc->__state &= ~__QDISC___STATE_RUNNING;
 118}
 119
 120static inline bool qdisc_may_bulk(const struct Qdisc *qdisc)
 121{
 122        return qdisc->flags & TCQ_F_ONETXQUEUE;
 123}
 124
 125static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq)
 126{
 127#ifdef CONFIG_BQL
 128        /* Non-BQL migrated drivers will return 0, too. */
 129        return dql_avail(&txq->dql);
 130#else
 131        return 0;
 132#endif
 133}
 134
 135static inline bool qdisc_is_throttled(const struct Qdisc *qdisc)
 136{
 137        return test_bit(__QDISC_STATE_THROTTLED, &qdisc->state) ? true : false;
 138}
 139
 140static inline void qdisc_throttled(struct Qdisc *qdisc)
 141{
 142        set_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
 143}
 144
 145static inline void qdisc_unthrottled(struct Qdisc *qdisc)
 146{
 147        clear_bit(__QDISC_STATE_THROTTLED, &qdisc->state);
 148}
 149
 150struct Qdisc_class_ops {
 151        /* Child qdisc manipulation */
 152        struct netdev_queue *   (*select_queue)(struct Qdisc *, struct tcmsg *);
 153        int                     (*graft)(struct Qdisc *, unsigned long cl,
 154                                        struct Qdisc *, struct Qdisc **);
 155        struct Qdisc *          (*leaf)(struct Qdisc *, unsigned long cl);
 156        void                    (*qlen_notify)(struct Qdisc *, unsigned long);
 157
 158        /* Class manipulation routines */
 159        unsigned long           (*get)(struct Qdisc *, u32 classid);
 160        void                    (*put)(struct Qdisc *, unsigned long);
 161        int                     (*change)(struct Qdisc *, u32, u32,
 162                                        struct nlattr **, unsigned long *);
 163        int                     (*delete)(struct Qdisc *, unsigned long);
 164        void                    (*walk)(struct Qdisc *, struct qdisc_walker * arg);
 165
 166        /* Filter manipulation */
 167        struct tcf_proto __rcu ** (*tcf_chain)(struct Qdisc *, unsigned long);
 168        unsigned long           (*bind_tcf)(struct Qdisc *, unsigned long,
 169                                        u32 classid);
 170        void                    (*unbind_tcf)(struct Qdisc *, unsigned long);
 171
 172        /* rtnetlink specific */
 173        int                     (*dump)(struct Qdisc *, unsigned long,
 174                                        struct sk_buff *skb, struct tcmsg*);
 175        int                     (*dump_stats)(struct Qdisc *, unsigned long,
 176                                        struct gnet_dump *);
 177};
 178
 179struct Qdisc_ops {
 180        struct Qdisc_ops        *next;
 181        const struct Qdisc_class_ops    *cl_ops;
 182        char                    id[IFNAMSIZ];
 183        int                     priv_size;
 184
 185        int                     (*enqueue)(struct sk_buff *, struct Qdisc *);
 186        struct sk_buff *        (*dequeue)(struct Qdisc *);
 187        struct sk_buff *        (*peek)(struct Qdisc *);
 188        unsigned int            (*drop)(struct Qdisc *);
 189
 190        int                     (*init)(struct Qdisc *, struct nlattr *arg);
 191        void                    (*reset)(struct Qdisc *);
 192        void                    (*destroy)(struct Qdisc *);
 193        int                     (*change)(struct Qdisc *, struct nlattr *arg);
 194        void                    (*attach)(struct Qdisc *);
 195
 196        int                     (*dump)(struct Qdisc *, struct sk_buff *);
 197        int                     (*dump_stats)(struct Qdisc *, struct gnet_dump *);
 198
 199        struct module           *owner;
 200};
 201
 202
 203struct tcf_result {
 204        unsigned long   class;
 205        u32             classid;
 206};
 207
 208struct tcf_proto_ops {
 209        struct list_head        head;
 210        char                    kind[IFNAMSIZ];
 211
 212        int                     (*classify)(struct sk_buff *,
 213                                            const struct tcf_proto *,
 214                                            struct tcf_result *);
 215        int                     (*init)(struct tcf_proto*);
 216        void                    (*destroy)(struct tcf_proto*);
 217
 218        unsigned long           (*get)(struct tcf_proto*, u32 handle);
 219        int                     (*change)(struct net *net, struct sk_buff *,
 220                                        struct tcf_proto*, unsigned long,
 221                                        u32 handle, struct nlattr **,
 222                                        unsigned long *, bool);
 223        int                     (*delete)(struct tcf_proto*, unsigned long);
 224        void                    (*walk)(struct tcf_proto*, struct tcf_walker *arg);
 225
 226        /* rtnetlink specific */
 227        int                     (*dump)(struct net*, struct tcf_proto*, unsigned long,
 228                                        struct sk_buff *skb, struct tcmsg*);
 229
 230        struct module           *owner;
 231};
 232
 233struct tcf_proto {
 234        /* Fast access part */
 235        struct tcf_proto __rcu  *next;
 236        void __rcu              *root;
 237        int                     (*classify)(struct sk_buff *,
 238                                            const struct tcf_proto *,
 239                                            struct tcf_result *);
 240        __be16                  protocol;
 241
 242        /* All the rest */
 243        u32                     prio;
 244        u32                     classid;
 245        struct Qdisc            *q;
 246        void                    *data;
 247        const struct tcf_proto_ops      *ops;
 248        struct rcu_head         rcu;
 249};
 250
 251struct qdisc_skb_cb {
 252        unsigned int            pkt_len;
 253        u16                     slave_dev_queue_mapping;
 254        u16                     _pad;
 255#define QDISC_CB_PRIV_LEN 20
 256        unsigned char           data[QDISC_CB_PRIV_LEN];
 257};
 258
 259static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
 260{
 261        struct qdisc_skb_cb *qcb;
 262
 263        BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz);
 264        BUILD_BUG_ON(sizeof(qcb->data) < sz);
 265}
 266
 267static inline int qdisc_qlen(const struct Qdisc *q)
 268{
 269        return q->q.qlen;
 270}
 271
 272static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb)
 273{
 274        return (struct qdisc_skb_cb *)skb->cb;
 275}
 276
 277static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
 278{
 279        return &qdisc->q.lock;
 280}
 281
 282static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc)
 283{
 284        struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc);
 285
 286        return q;
 287}
 288
 289static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc)
 290{
 291        return qdisc->dev_queue->qdisc_sleeping;
 292}
 293
 294/* The qdisc root lock is a mechanism by which to top level
 295 * of a qdisc tree can be locked from any qdisc node in the
 296 * forest.  This allows changing the configuration of some
 297 * aspect of the qdisc tree while blocking out asynchronous
 298 * qdisc access in the packet processing paths.
 299 *
 300 * It is only legal to do this when the root will not change
 301 * on us.  Otherwise we'll potentially lock the wrong qdisc
 302 * root.  This is enforced by holding the RTNL semaphore, which
 303 * all users of this lock accessor must do.
 304 */
 305static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc)
 306{
 307        struct Qdisc *root = qdisc_root(qdisc);
 308
 309        ASSERT_RTNL();
 310        return qdisc_lock(root);
 311}
 312
 313static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc)
 314{
 315        struct Qdisc *root = qdisc_root_sleeping(qdisc);
 316
 317        ASSERT_RTNL();
 318        return qdisc_lock(root);
 319}
 320
 321static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc)
 322{
 323        return qdisc->dev_queue->dev;
 324}
 325
 326static inline void sch_tree_lock(const struct Qdisc *q)
 327{
 328        spin_lock_bh(qdisc_root_sleeping_lock(q));
 329}
 330
 331static inline void sch_tree_unlock(const struct Qdisc *q)
 332{
 333        spin_unlock_bh(qdisc_root_sleeping_lock(q));
 334}
 335
 336#define tcf_tree_lock(tp)       sch_tree_lock((tp)->q)
 337#define tcf_tree_unlock(tp)     sch_tree_unlock((tp)->q)
 338
 339extern struct Qdisc noop_qdisc;
 340extern struct Qdisc_ops noop_qdisc_ops;
 341extern struct Qdisc_ops pfifo_fast_ops;
 342extern struct Qdisc_ops mq_qdisc_ops;
 343extern const struct Qdisc_ops *default_qdisc_ops;
 344
 345struct Qdisc_class_common {
 346        u32                     classid;
 347        struct hlist_node       hnode;
 348};
 349
 350struct Qdisc_class_hash {
 351        struct hlist_head       *hash;
 352        unsigned int            hashsize;
 353        unsigned int            hashmask;
 354        unsigned int            hashelems;
 355};
 356
 357static inline unsigned int qdisc_class_hash(u32 id, u32 mask)
 358{
 359        id ^= id >> 8;
 360        id ^= id >> 4;
 361        return id & mask;
 362}
 363
 364static inline struct Qdisc_class_common *
 365qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id)
 366{
 367        struct Qdisc_class_common *cl;
 368        unsigned int h;
 369
 370        h = qdisc_class_hash(id, hash->hashmask);
 371        hlist_for_each_entry(cl, &hash->hash[h], hnode) {
 372                if (cl->classid == id)
 373                        return cl;
 374        }
 375        return NULL;
 376}
 377
 378int qdisc_class_hash_init(struct Qdisc_class_hash *);
 379void qdisc_class_hash_insert(struct Qdisc_class_hash *,
 380                             struct Qdisc_class_common *);
 381void qdisc_class_hash_remove(struct Qdisc_class_hash *,
 382                             struct Qdisc_class_common *);
 383void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *);
 384void qdisc_class_hash_destroy(struct Qdisc_class_hash *);
 385
 386void dev_init_scheduler(struct net_device *dev);
 387void dev_shutdown(struct net_device *dev);
 388void dev_activate(struct net_device *dev);
 389void dev_deactivate(struct net_device *dev);
 390void dev_deactivate_many(struct list_head *head);
 391struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
 392                              struct Qdisc *qdisc);
 393void qdisc_reset(struct Qdisc *qdisc);
 394void qdisc_destroy(struct Qdisc *qdisc);
 395void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
 396struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 397                          const struct Qdisc_ops *ops);
 398struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
 399                                const struct Qdisc_ops *ops, u32 parentid);
 400void __qdisc_calculate_pkt_len(struct sk_buff *skb,
 401                               const struct qdisc_size_table *stab);
 402void tcf_destroy(struct tcf_proto *tp);
 403void tcf_destroy_chain(struct tcf_proto __rcu **fl);
 404
 405/* Reset all TX qdiscs greater then index of a device.  */
 406static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
 407{
 408        struct Qdisc *qdisc;
 409
 410        for (; i < dev->num_tx_queues; i++) {
 411                qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc);
 412                if (qdisc) {
 413                        spin_lock_bh(qdisc_lock(qdisc));
 414                        qdisc_reset(qdisc);
 415                        spin_unlock_bh(qdisc_lock(qdisc));
 416                }
 417        }
 418}
 419
 420static inline void qdisc_reset_all_tx(struct net_device *dev)
 421{
 422        qdisc_reset_all_tx_gt(dev, 0);
 423}
 424
 425/* Are all TX queues of the device empty?  */
 426static inline bool qdisc_all_tx_empty(const struct net_device *dev)
 427{
 428        unsigned int i;
 429
 430        rcu_read_lock();
 431        for (i = 0; i < dev->num_tx_queues; i++) {
 432                struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 433                const struct Qdisc *q = rcu_dereference(txq->qdisc);
 434
 435                if (q->q.qlen) {
 436                        rcu_read_unlock();
 437                        return false;
 438                }
 439        }
 440        rcu_read_unlock();
 441        return true;
 442}
 443
 444/* Are any of the TX qdiscs changing?  */
 445static inline bool qdisc_tx_changing(const struct net_device *dev)
 446{
 447        unsigned int i;
 448
 449        for (i = 0; i < dev->num_tx_queues; i++) {
 450                struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 451                if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping)
 452                        return true;
 453        }
 454        return false;
 455}
 456
 457/* Is the device using the noop qdisc on all queues?  */
 458static inline bool qdisc_tx_is_noop(const struct net_device *dev)
 459{
 460        unsigned int i;
 461
 462        for (i = 0; i < dev->num_tx_queues; i++) {
 463                struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
 464                if (rcu_access_pointer(txq->qdisc) != &noop_qdisc)
 465                        return false;
 466        }
 467        return true;
 468}
 469
 470static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb)
 471{
 472        return qdisc_skb_cb(skb)->pkt_len;
 473}
 474
 475/* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */
 476enum net_xmit_qdisc_t {
 477        __NET_XMIT_STOLEN = 0x00010000,
 478        __NET_XMIT_BYPASS = 0x00020000,
 479};
 480
 481#ifdef CONFIG_NET_CLS_ACT
 482#define net_xmit_drop_count(e)  ((e) & __NET_XMIT_STOLEN ? 0 : 1)
 483#else
 484#define net_xmit_drop_count(e)  (1)
 485#endif
 486
 487static inline void qdisc_calculate_pkt_len(struct sk_buff *skb,
 488                                           const struct Qdisc *sch)
 489{
 490#ifdef CONFIG_NET_SCHED
 491        struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab);
 492
 493        if (stab)
 494                __qdisc_calculate_pkt_len(skb, stab);
 495#endif
 496}
 497
 498static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 499{
 500        qdisc_calculate_pkt_len(skb, sch);
 501        return sch->enqueue(skb, sch);
 502}
 503
 504static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
 505{
 506        qdisc_skb_cb(skb)->pkt_len = skb->len;
 507        return qdisc_enqueue(skb, sch) & NET_XMIT_MASK;
 508}
 509
 510static inline bool qdisc_is_percpu_stats(const struct Qdisc *q)
 511{
 512        return q->flags & TCQ_F_CPUSTATS;
 513}
 514
 515static inline void bstats_update(struct gnet_stats_basic_packed *bstats,
 516                                 const struct sk_buff *skb)
 517{
 518        bstats->bytes += qdisc_pkt_len(skb);
 519        bstats->packets += skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1;
 520}
 521
 522static inline void qdisc_bstats_update_cpu(struct Qdisc *sch,
 523                                           const struct sk_buff *skb)
 524{
 525        struct gnet_stats_basic_cpu *bstats =
 526                                this_cpu_ptr(sch->cpu_bstats);
 527
 528        u64_stats_update_begin(&bstats->syncp);
 529        bstats_update(&bstats->bstats, skb);
 530        u64_stats_update_end(&bstats->syncp);
 531}
 532
 533static inline void qdisc_bstats_update(struct Qdisc *sch,
 534                                       const struct sk_buff *skb)
 535{
 536        bstats_update(&sch->bstats, skb);
 537}
 538
 539static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch,
 540                                            const struct sk_buff *skb)
 541{
 542        sch->qstats.backlog -= qdisc_pkt_len(skb);
 543}
 544
 545static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch,
 546                                            const struct sk_buff *skb)
 547{
 548        sch->qstats.backlog += qdisc_pkt_len(skb);
 549}
 550
 551static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count)
 552{
 553        sch->qstats.drops += count;
 554}
 555
 556static inline void qdisc_qstats_drop(struct Qdisc *sch)
 557{
 558        sch->qstats.drops++;
 559}
 560
 561static inline void qdisc_qstats_drop_cpu(struct Qdisc *sch)
 562{
 563        struct gnet_stats_queue *qstats = this_cpu_ptr(sch->cpu_qstats);
 564
 565        qstats->drops++;
 566}
 567
 568static inline void qdisc_qstats_overlimit(struct Qdisc *sch)
 569{
 570        sch->qstats.overlimits++;
 571}
 572
 573static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch,
 574                                       struct sk_buff_head *list)
 575{
 576        __skb_queue_tail(list, skb);
 577        qdisc_qstats_backlog_inc(sch, skb);
 578
 579        return NET_XMIT_SUCCESS;
 580}
 581
 582static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch)
 583{
 584        return __qdisc_enqueue_tail(skb, sch, &sch->q);
 585}
 586
 587static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch,
 588                                                   struct sk_buff_head *list)
 589{
 590        struct sk_buff *skb = __skb_dequeue(list);
 591
 592        if (likely(skb != NULL)) {
 593                qdisc_qstats_backlog_dec(sch, skb);
 594                qdisc_bstats_update(sch, skb);
 595        }
 596
 597        return skb;
 598}
 599
 600static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch)
 601{
 602        return __qdisc_dequeue_head(sch, &sch->q);
 603}
 604
 605static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch,
 606                                              struct sk_buff_head *list)
 607{
 608        struct sk_buff *skb = __skb_dequeue(list);
 609
 610        if (likely(skb != NULL)) {
 611                unsigned int len = qdisc_pkt_len(skb);
 612                qdisc_qstats_backlog_dec(sch, skb);
 613                kfree_skb(skb);
 614                return len;
 615        }
 616
 617        return 0;
 618}
 619
 620static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch)
 621{
 622        return __qdisc_queue_drop_head(sch, &sch->q);
 623}
 624
 625static inline struct sk_buff *__qdisc_dequeue_tail(struct Qdisc *sch,
 626                                                   struct sk_buff_head *list)
 627{
 628        struct sk_buff *skb = __skb_dequeue_tail(list);
 629
 630        if (likely(skb != NULL))
 631                qdisc_qstats_backlog_dec(sch, skb);
 632
 633        return skb;
 634}
 635
 636static inline struct sk_buff *qdisc_dequeue_tail(struct Qdisc *sch)
 637{
 638        return __qdisc_dequeue_tail(sch, &sch->q);
 639}
 640
 641static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch)
 642{
 643        return skb_peek(&sch->q);
 644}
 645
 646/* generic pseudo peek method for non-work-conserving qdisc */
 647static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch)
 648{
 649        /* we can reuse ->gso_skb because peek isn't called for root qdiscs */
 650        if (!sch->gso_skb) {
 651                sch->gso_skb = sch->dequeue(sch);
 652                if (sch->gso_skb)
 653                        /* it's still part of the queue */
 654                        sch->q.qlen++;
 655        }
 656
 657        return sch->gso_skb;
 658}
 659
 660/* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */
 661static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch)
 662{
 663        struct sk_buff *skb = sch->gso_skb;
 664
 665        if (skb) {
 666                sch->gso_skb = NULL;
 667                sch->q.qlen--;
 668        } else {
 669                skb = sch->dequeue(sch);
 670        }
 671
 672        return skb;
 673}
 674
 675static inline void __qdisc_reset_queue(struct Qdisc *sch,
 676                                       struct sk_buff_head *list)
 677{
 678        /*
 679         * We do not know the backlog in bytes of this list, it
 680         * is up to the caller to correct it
 681         */
 682        __skb_queue_purge(list);
 683}
 684
 685static inline void qdisc_reset_queue(struct Qdisc *sch)
 686{
 687        __qdisc_reset_queue(sch, &sch->q);
 688        sch->qstats.backlog = 0;
 689}
 690
 691static inline unsigned int __qdisc_queue_drop(struct Qdisc *sch,
 692                                              struct sk_buff_head *list)
 693{
 694        struct sk_buff *skb = __qdisc_dequeue_tail(sch, list);
 695
 696        if (likely(skb != NULL)) {
 697                unsigned int len = qdisc_pkt_len(skb);
 698                kfree_skb(skb);
 699                return len;
 700        }
 701
 702        return 0;
 703}
 704
 705static inline unsigned int qdisc_queue_drop(struct Qdisc *sch)
 706{
 707        return __qdisc_queue_drop(sch, &sch->q);
 708}
 709
 710static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch)
 711{
 712        kfree_skb(skb);
 713        qdisc_qstats_drop(sch);
 714
 715        return NET_XMIT_DROP;
 716}
 717
 718static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
 719{
 720        qdisc_qstats_drop(sch);
 721
 722#ifdef CONFIG_NET_CLS_ACT
 723        if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
 724                goto drop;
 725
 726        return NET_XMIT_SUCCESS;
 727
 728drop:
 729#endif
 730        kfree_skb(skb);
 731        return NET_XMIT_DROP;
 732}
 733
 734/* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how
 735   long it will take to send a packet given its size.
 736 */
 737static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen)
 738{
 739        int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead;
 740        if (slot < 0)
 741                slot = 0;
 742        slot >>= rtab->rate.cell_log;
 743        if (slot > 255)
 744                return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF];
 745        return rtab->data[slot];
 746}
 747
 748#ifdef CONFIG_NET_CLS_ACT
 749static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask,
 750                                            int action)
 751{
 752        struct sk_buff *n;
 753
 754        n = skb_clone(skb, gfp_mask);
 755
 756        if (n) {
 757                n->tc_verd = SET_TC_VERD(n->tc_verd, 0);
 758                n->tc_verd = CLR_TC_OK2MUNGE(n->tc_verd);
 759                n->tc_verd = CLR_TC_MUNGED(n->tc_verd);
 760        }
 761        return n;
 762}
 763#endif
 764
 765struct psched_ratecfg {
 766        u64     rate_bytes_ps; /* bytes per second */
 767        u32     mult;
 768        u16     overhead;
 769        u8      linklayer;
 770        u8      shift;
 771};
 772
 773static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,
 774                                unsigned int len)
 775{
 776        len += r->overhead;
 777
 778        if (unlikely(r->linklayer == TC_LINKLAYER_ATM))
 779                return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift;
 780
 781        return ((u64)len * r->mult) >> r->shift;
 782}
 783
 784void psched_ratecfg_precompute(struct psched_ratecfg *r,
 785                               const struct tc_ratespec *conf,
 786                               u64 rate64);
 787
 788static inline void psched_ratecfg_getrate(struct tc_ratespec *res,
 789                                          const struct psched_ratecfg *r)
 790{
 791        memset(res, 0, sizeof(*res));
 792
 793        /* legacy struct tc_ratespec has a 32bit @rate field
 794         * Qdisc using 64bit rate should add new attributes
 795         * in order to maintain compatibility.
 796         */
 797        res->rate = min_t(u64, r->rate_bytes_ps, ~0U);
 798
 799        res->overhead = r->overhead;
 800        res->linklayer = (r->linklayer & TC_LINKLAYER_MASK);
 801}
 802
 803#endif
 804