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 14 struct Qdisc_ops; 15 struct qdisc_walker; 16 struct tcf_walker; 17 struct module; 18 19 struct qdisc_rate_table { 20 struct tc_ratespec rate; 21 u32 data[256]; 22 struct qdisc_rate_table *next; 23 int refcnt; 24 }; 25 26 enum qdisc_state_t { 27 __QDISC_STATE_SCHED, 28 __QDISC_STATE_DEACTIVATED, 29 }; 30 31 struct qdisc_size_table { 32 struct rcu_head rcu; 33 struct list_head list; 34 struct tc_sizespec szopts; 35 int refcnt; 36 u16 data[]; 37 }; 38 39 struct Qdisc { 40 int (*enqueue)(struct sk_buff *skb, struct Qdisc *dev); 41 struct sk_buff * (*dequeue)(struct Qdisc *dev); 42 unsigned int flags; 43 #define TCQ_F_BUILTIN 1 44 #define TCQ_F_INGRESS 2 45 #define TCQ_F_CAN_BYPASS 4 46 #define TCQ_F_MQROOT 8 47 #define TCQ_F_ONETXQUEUE 0x10 /* dequeue_skb() can assume all skbs are for 48 * q->dev_queue : It can test 49 * netif_xmit_frozen_or_stopped() before 50 * dequeueing next packet. 51 * Its true for MQ/MQPRIO slaves, or non 52 * multiqueue device. 53 */ 54 #define TCQ_F_WARN_NONWC (1 << 16) 55 #define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */ 56 #define TCQ_F_NOPARENT 0x40 /* root of its hierarchy : 57 * qdisc_tree_decrease_qlen() should stop. 58 */ 59 u32 limit; 60 const struct Qdisc_ops *ops; 61 struct qdisc_size_table __rcu *stab; 62 struct list_head list; 63 u32 handle; 64 u32 parent; 65 void *u32_node; 66 67 struct netdev_queue *dev_queue; 68 69 struct gnet_stats_rate_est64 rate_est; 70 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 71 struct gnet_stats_queue __percpu *cpu_qstats; 72 73 /* 74 * For performance sake on SMP, we put highly modified fields at the end 75 */ 76 struct Qdisc *next_sched ____cacheline_aligned_in_smp; 77 struct sk_buff *gso_skb; 78 unsigned long state; 79 struct sk_buff_head q; 80 struct gnet_stats_basic_packed bstats; 81 seqcount_t running; 82 struct gnet_stats_queue qstats; 83 struct rcu_head rcu_head; 84 int padded; 85 atomic_t refcnt; 86 87 spinlock_t busylock ____cacheline_aligned_in_smp; 88 }; 89 90 static inline bool qdisc_is_running(const struct Qdisc *qdisc) 91 { 92 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; 93 } 94 95 static inline bool qdisc_run_begin(struct Qdisc *qdisc) 96 { 97 if (qdisc_is_running(qdisc)) 98 return false; 99 /* Variant of write_seqcount_begin() telling lockdep a trylock 100 * was attempted. 101 */ 102 raw_write_seqcount_begin(&qdisc->running); 103 seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); 104 return true; 105 } 106 107 static inline void qdisc_run_end(struct Qdisc *qdisc) 108 { 109 write_seqcount_end(&qdisc->running); 110 } 111 112 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) 113 { 114 return qdisc->flags & TCQ_F_ONETXQUEUE; 115 } 116 117 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq) 118 { 119 #ifdef CONFIG_BQL 120 /* Non-BQL migrated drivers will return 0, too. */ 121 return dql_avail(&txq->dql); 122 #else 123 return 0; 124 #endif 125 } 126 127 struct Qdisc_class_ops { 128 /* Child qdisc manipulation */ 129 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *); 130 int (*graft)(struct Qdisc *, unsigned long cl, 131 struct Qdisc *, struct Qdisc **); 132 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl); 133 void (*qlen_notify)(struct Qdisc *, unsigned long); 134 135 /* Class manipulation routines */ 136 unsigned long (*get)(struct Qdisc *, u32 classid); 137 void (*put)(struct Qdisc *, unsigned long); 138 int (*change)(struct Qdisc *, u32, u32, 139 struct nlattr **, unsigned long *); 140 int (*delete)(struct Qdisc *, unsigned long); 141 void (*walk)(struct Qdisc *, struct qdisc_walker * arg); 142 143 /* Filter manipulation */ 144 struct tcf_proto __rcu ** (*tcf_chain)(struct Qdisc *, unsigned long); 145 bool (*tcf_cl_offload)(u32 classid); 146 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 147 u32 classid); 148 void (*unbind_tcf)(struct Qdisc *, unsigned long); 149 150 /* rtnetlink specific */ 151 int (*dump)(struct Qdisc *, unsigned long, 152 struct sk_buff *skb, struct tcmsg*); 153 int (*dump_stats)(struct Qdisc *, unsigned long, 154 struct gnet_dump *); 155 }; 156 157 struct Qdisc_ops { 158 struct Qdisc_ops *next; 159 const struct Qdisc_class_ops *cl_ops; 160 char id[IFNAMSIZ]; 161 int priv_size; 162 163 int (*enqueue)(struct sk_buff *, struct Qdisc *); 164 struct sk_buff * (*dequeue)(struct Qdisc *); 165 struct sk_buff * (*peek)(struct Qdisc *); 166 167 int (*init)(struct Qdisc *, struct nlattr *arg); 168 void (*reset)(struct Qdisc *); 169 void (*destroy)(struct Qdisc *); 170 int (*change)(struct Qdisc *, struct nlattr *arg); 171 void (*attach)(struct Qdisc *); 172 173 int (*dump)(struct Qdisc *, struct sk_buff *); 174 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 175 176 struct module *owner; 177 }; 178 179 180 struct tcf_result { 181 unsigned long class; 182 u32 classid; 183 }; 184 185 struct tcf_proto_ops { 186 struct list_head head; 187 char kind[IFNAMSIZ]; 188 189 int (*classify)(struct sk_buff *, 190 const struct tcf_proto *, 191 struct tcf_result *); 192 int (*init)(struct tcf_proto*); 193 bool (*destroy)(struct tcf_proto*, bool); 194 195 unsigned long (*get)(struct tcf_proto*, u32 handle); 196 int (*change)(struct net *net, struct sk_buff *, 197 struct tcf_proto*, unsigned long, 198 u32 handle, struct nlattr **, 199 unsigned long *, bool); 200 int (*delete)(struct tcf_proto*, unsigned long); 201 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 202 203 /* rtnetlink specific */ 204 int (*dump)(struct net*, struct tcf_proto*, unsigned long, 205 struct sk_buff *skb, struct tcmsg*); 206 207 struct module *owner; 208 }; 209 210 struct tcf_proto { 211 /* Fast access part */ 212 struct tcf_proto __rcu *next; 213 void __rcu *root; 214 int (*classify)(struct sk_buff *, 215 const struct tcf_proto *, 216 struct tcf_result *); 217 __be16 protocol; 218 219 /* All the rest */ 220 u32 prio; 221 u32 classid; 222 struct Qdisc *q; 223 void *data; 224 const struct tcf_proto_ops *ops; 225 struct rcu_head rcu; 226 }; 227 228 struct qdisc_skb_cb { 229 unsigned int pkt_len; 230 u16 slave_dev_queue_mapping; 231 u16 tc_classid; 232 #define QDISC_CB_PRIV_LEN 20 233 unsigned char data[QDISC_CB_PRIV_LEN]; 234 }; 235 236 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 237 { 238 struct qdisc_skb_cb *qcb; 239 240 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 241 BUILD_BUG_ON(sizeof(qcb->data) < sz); 242 } 243 244 static inline int qdisc_qlen(const struct Qdisc *q) 245 { 246 return q->q.qlen; 247 } 248 249 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 250 { 251 return (struct qdisc_skb_cb *)skb->cb; 252 } 253 254 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 255 { 256 return &qdisc->q.lock; 257 } 258 259 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 260 { 261 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 262 263 return q; 264 } 265 266 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 267 { 268 return qdisc->dev_queue->qdisc_sleeping; 269 } 270 271 /* The qdisc root lock is a mechanism by which to top level 272 * of a qdisc tree can be locked from any qdisc node in the 273 * forest. This allows changing the configuration of some 274 * aspect of the qdisc tree while blocking out asynchronous 275 * qdisc access in the packet processing paths. 276 * 277 * It is only legal to do this when the root will not change 278 * on us. Otherwise we'll potentially lock the wrong qdisc 279 * root. This is enforced by holding the RTNL semaphore, which 280 * all users of this lock accessor must do. 281 */ 282 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 283 { 284 struct Qdisc *root = qdisc_root(qdisc); 285 286 ASSERT_RTNL(); 287 return qdisc_lock(root); 288 } 289 290 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 291 { 292 struct Qdisc *root = qdisc_root_sleeping(qdisc); 293 294 ASSERT_RTNL(); 295 return qdisc_lock(root); 296 } 297 298 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 299 { 300 struct Qdisc *root = qdisc_root_sleeping(qdisc); 301 302 ASSERT_RTNL(); 303 return &root->running; 304 } 305 306 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 307 { 308 return qdisc->dev_queue->dev; 309 } 310 311 static inline void sch_tree_lock(const struct Qdisc *q) 312 { 313 spin_lock_bh(qdisc_root_sleeping_lock(q)); 314 } 315 316 static inline void sch_tree_unlock(const struct Qdisc *q) 317 { 318 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 319 } 320 321 #define tcf_tree_lock(tp) sch_tree_lock((tp)->q) 322 #define tcf_tree_unlock(tp) sch_tree_unlock((tp)->q) 323 324 extern struct Qdisc noop_qdisc; 325 extern struct Qdisc_ops noop_qdisc_ops; 326 extern struct Qdisc_ops pfifo_fast_ops; 327 extern struct Qdisc_ops mq_qdisc_ops; 328 extern struct Qdisc_ops noqueue_qdisc_ops; 329 extern const struct Qdisc_ops *default_qdisc_ops; 330 static inline const struct Qdisc_ops * 331 get_default_qdisc_ops(const struct net_device *dev, int ntx) 332 { 333 return ntx < dev->real_num_tx_queues ? 334 default_qdisc_ops : &pfifo_fast_ops; 335 } 336 337 struct Qdisc_class_common { 338 u32 classid; 339 struct hlist_node hnode; 340 }; 341 342 struct Qdisc_class_hash { 343 struct hlist_head *hash; 344 unsigned int hashsize; 345 unsigned int hashmask; 346 unsigned int hashelems; 347 }; 348 349 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 350 { 351 id ^= id >> 8; 352 id ^= id >> 4; 353 return id & mask; 354 } 355 356 static inline struct Qdisc_class_common * 357 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 358 { 359 struct Qdisc_class_common *cl; 360 unsigned int h; 361 362 h = qdisc_class_hash(id, hash->hashmask); 363 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 364 if (cl->classid == id) 365 return cl; 366 } 367 return NULL; 368 } 369 370 int qdisc_class_hash_init(struct Qdisc_class_hash *); 371 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 372 struct Qdisc_class_common *); 373 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 374 struct Qdisc_class_common *); 375 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 376 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 377 378 void dev_init_scheduler(struct net_device *dev); 379 void dev_shutdown(struct net_device *dev); 380 void dev_activate(struct net_device *dev); 381 void dev_deactivate(struct net_device *dev); 382 void dev_deactivate_many(struct list_head *head); 383 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 384 struct Qdisc *qdisc); 385 void qdisc_reset(struct Qdisc *qdisc); 386 void qdisc_destroy(struct Qdisc *qdisc); 387 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 388 unsigned int len); 389 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 390 const struct Qdisc_ops *ops); 391 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 392 const struct Qdisc_ops *ops, u32 parentid); 393 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 394 const struct qdisc_size_table *stab); 395 bool tcf_destroy(struct tcf_proto *tp, bool force); 396 void tcf_destroy_chain(struct tcf_proto __rcu **fl); 397 int skb_do_redirect(struct sk_buff *); 398 399 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 400 { 401 #ifdef CONFIG_NET_CLS_ACT 402 return G_TC_AT(skb->tc_verd) & AT_INGRESS; 403 #else 404 return false; 405 #endif 406 } 407 408 /* Reset all TX qdiscs greater then index of a device. */ 409 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 410 { 411 struct Qdisc *qdisc; 412 413 for (; i < dev->num_tx_queues; i++) { 414 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 415 if (qdisc) { 416 spin_lock_bh(qdisc_lock(qdisc)); 417 qdisc_reset(qdisc); 418 spin_unlock_bh(qdisc_lock(qdisc)); 419 } 420 } 421 } 422 423 static inline void qdisc_reset_all_tx(struct net_device *dev) 424 { 425 qdisc_reset_all_tx_gt(dev, 0); 426 } 427 428 /* Are all TX queues of the device empty? */ 429 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 430 { 431 unsigned int i; 432 433 rcu_read_lock(); 434 for (i = 0; i < dev->num_tx_queues; i++) { 435 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 436 const struct Qdisc *q = rcu_dereference(txq->qdisc); 437 438 if (q->q.qlen) { 439 rcu_read_unlock(); 440 return false; 441 } 442 } 443 rcu_read_unlock(); 444 return true; 445 } 446 447 /* Are any of the TX qdiscs changing? */ 448 static inline bool qdisc_tx_changing(const struct net_device *dev) 449 { 450 unsigned int i; 451 452 for (i = 0; i < dev->num_tx_queues; i++) { 453 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 454 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 455 return true; 456 } 457 return false; 458 } 459 460 /* Is the device using the noop qdisc on all queues? */ 461 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 462 { 463 unsigned int i; 464 465 for (i = 0; i < dev->num_tx_queues; i++) { 466 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 467 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 468 return false; 469 } 470 return true; 471 } 472 473 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 474 { 475 return qdisc_skb_cb(skb)->pkt_len; 476 } 477 478 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 479 enum net_xmit_qdisc_t { 480 __NET_XMIT_STOLEN = 0x00010000, 481 __NET_XMIT_BYPASS = 0x00020000, 482 }; 483 484 #ifdef CONFIG_NET_CLS_ACT 485 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 486 #else 487 #define net_xmit_drop_count(e) (1) 488 #endif 489 490 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 491 const struct Qdisc *sch) 492 { 493 #ifdef CONFIG_NET_SCHED 494 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 495 496 if (stab) 497 __qdisc_calculate_pkt_len(skb, stab); 498 #endif 499 } 500 501 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch) 502 { 503 qdisc_calculate_pkt_len(skb, sch); 504 return sch->enqueue(skb, sch); 505 } 506 507 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 508 { 509 return q->flags & TCQ_F_CPUSTATS; 510 } 511 512 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 513 __u64 bytes, __u32 packets) 514 { 515 bstats->bytes += bytes; 516 bstats->packets += packets; 517 } 518 519 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 520 const struct sk_buff *skb) 521 { 522 _bstats_update(bstats, 523 qdisc_pkt_len(skb), 524 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 525 } 526 527 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 528 __u64 bytes, __u32 packets) 529 { 530 u64_stats_update_begin(&bstats->syncp); 531 _bstats_update(&bstats->bstats, bytes, packets); 532 u64_stats_update_end(&bstats->syncp); 533 } 534 535 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 536 const struct sk_buff *skb) 537 { 538 u64_stats_update_begin(&bstats->syncp); 539 bstats_update(&bstats->bstats, skb); 540 u64_stats_update_end(&bstats->syncp); 541 } 542 543 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 544 const struct sk_buff *skb) 545 { 546 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 547 } 548 549 static inline void qdisc_bstats_update(struct Qdisc *sch, 550 const struct sk_buff *skb) 551 { 552 bstats_update(&sch->bstats, skb); 553 } 554 555 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 556 const struct sk_buff *skb) 557 { 558 sch->qstats.backlog -= qdisc_pkt_len(skb); 559 } 560 561 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 562 const struct sk_buff *skb) 563 { 564 sch->qstats.backlog += qdisc_pkt_len(skb); 565 } 566 567 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 568 { 569 sch->qstats.drops += count; 570 } 571 572 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 573 { 574 qstats->drops++; 575 } 576 577 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 578 { 579 qstats->overlimits++; 580 } 581 582 static inline void qdisc_qstats_drop(struct Qdisc *sch) 583 { 584 qstats_drop_inc(&sch->qstats); 585 } 586 587 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 588 { 589 qstats_drop_inc(this_cpu_ptr(sch->cpu_qstats)); 590 } 591 592 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 593 { 594 sch->qstats.overlimits++; 595 } 596 597 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 598 struct sk_buff_head *list) 599 { 600 __skb_queue_tail(list, skb); 601 qdisc_qstats_backlog_inc(sch, skb); 602 603 return NET_XMIT_SUCCESS; 604 } 605 606 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 607 { 608 return __qdisc_enqueue_tail(skb, sch, &sch->q); 609 } 610 611 static inline struct sk_buff *__qdisc_dequeue_head(struct Qdisc *sch, 612 struct sk_buff_head *list) 613 { 614 struct sk_buff *skb = __skb_dequeue(list); 615 616 if (likely(skb != NULL)) { 617 qdisc_qstats_backlog_dec(sch, skb); 618 qdisc_bstats_update(sch, skb); 619 } 620 621 return skb; 622 } 623 624 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 625 { 626 return __qdisc_dequeue_head(sch, &sch->q); 627 } 628 629 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 630 struct sk_buff_head *list) 631 { 632 struct sk_buff *skb = __skb_dequeue(list); 633 634 if (likely(skb != NULL)) { 635 unsigned int len = qdisc_pkt_len(skb); 636 qdisc_qstats_backlog_dec(sch, skb); 637 kfree_skb(skb); 638 return len; 639 } 640 641 return 0; 642 } 643 644 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch) 645 { 646 return __qdisc_queue_drop_head(sch, &sch->q); 647 } 648 649 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 650 { 651 return skb_peek(&sch->q); 652 } 653 654 /* generic pseudo peek method for non-work-conserving qdisc */ 655 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 656 { 657 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 658 if (!sch->gso_skb) { 659 sch->gso_skb = sch->dequeue(sch); 660 if (sch->gso_skb) { 661 /* it's still part of the queue */ 662 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 663 sch->q.qlen++; 664 } 665 } 666 667 return sch->gso_skb; 668 } 669 670 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 671 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 672 { 673 struct sk_buff *skb = sch->gso_skb; 674 675 if (skb) { 676 sch->gso_skb = NULL; 677 qdisc_qstats_backlog_dec(sch, skb); 678 sch->q.qlen--; 679 } else { 680 skb = sch->dequeue(sch); 681 } 682 683 return skb; 684 } 685 686 static inline void __qdisc_reset_queue(struct sk_buff_head *list) 687 { 688 /* 689 * We do not know the backlog in bytes of this list, it 690 * is up to the caller to correct it 691 */ 692 if (!skb_queue_empty(list)) { 693 rtnl_kfree_skbs(list->next, list->prev); 694 __skb_queue_head_init(list); 695 } 696 } 697 698 static inline void qdisc_reset_queue(struct Qdisc *sch) 699 { 700 __qdisc_reset_queue(&sch->q); 701 sch->qstats.backlog = 0; 702 } 703 704 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 705 struct Qdisc **pold) 706 { 707 struct Qdisc *old; 708 709 sch_tree_lock(sch); 710 old = *pold; 711 *pold = new; 712 if (old != NULL) { 713 qdisc_tree_reduce_backlog(old, old->q.qlen, old->qstats.backlog); 714 qdisc_reset(old); 715 } 716 sch_tree_unlock(sch); 717 718 return old; 719 } 720 721 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 722 { 723 rtnl_kfree_skbs(skb, skb); 724 qdisc_qstats_drop(sch); 725 } 726 727 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 728 { 729 kfree_skb(skb); 730 qdisc_qstats_drop(sch); 731 732 return NET_XMIT_DROP; 733 } 734 735 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 736 long it will take to send a packet given its size. 737 */ 738 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 739 { 740 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 741 if (slot < 0) 742 slot = 0; 743 slot >>= rtab->rate.cell_log; 744 if (slot > 255) 745 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 746 return rtab->data[slot]; 747 } 748 749 struct psched_ratecfg { 750 u64 rate_bytes_ps; /* bytes per second */ 751 u32 mult; 752 u16 overhead; 753 u8 linklayer; 754 u8 shift; 755 }; 756 757 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 758 unsigned int len) 759 { 760 len += r->overhead; 761 762 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 763 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 764 765 return ((u64)len * r->mult) >> r->shift; 766 } 767 768 void psched_ratecfg_precompute(struct psched_ratecfg *r, 769 const struct tc_ratespec *conf, 770 u64 rate64); 771 772 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 773 const struct psched_ratecfg *r) 774 { 775 memset(res, 0, sizeof(*res)); 776 777 /* legacy struct tc_ratespec has a 32bit @rate field 778 * Qdisc using 64bit rate should add new attributes 779 * in order to maintain compatibility. 780 */ 781 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 782 783 res->overhead = r->overhead; 784 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 785 } 786 787 #endif 788