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