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