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 /* similar to sk_buff_head, but skb->prev pointer is undefined. */ 40 struct qdisc_skb_head { 41 struct sk_buff *head; 42 struct sk_buff *tail; 43 __u32 qlen; 44 spinlock_t lock; 45 }; 46 47 struct Qdisc { 48 int (*enqueue)(struct sk_buff *skb, 49 struct Qdisc *sch, 50 struct sk_buff **to_free); 51 struct sk_buff * (*dequeue)(struct Qdisc *sch); 52 unsigned int flags; 53 #define TCQ_F_BUILTIN 1 54 #define TCQ_F_INGRESS 2 55 #define TCQ_F_CAN_BYPASS 4 56 #define TCQ_F_MQROOT 8 57 #define TCQ_F_ONETXQUEUE 0x10 /* dequeue_skb() can assume all skbs are for 58 * q->dev_queue : It can test 59 * netif_xmit_frozen_or_stopped() before 60 * dequeueing next packet. 61 * Its true for MQ/MQPRIO slaves, or non 62 * multiqueue device. 63 */ 64 #define TCQ_F_WARN_NONWC (1 << 16) 65 #define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */ 66 #define TCQ_F_NOPARENT 0x40 /* root of its hierarchy : 67 * qdisc_tree_decrease_qlen() should stop. 68 */ 69 #define TCQ_F_INVISIBLE 0x80 /* invisible by default in dump */ 70 u32 limit; 71 const struct Qdisc_ops *ops; 72 struct qdisc_size_table __rcu *stab; 73 struct hlist_node hash; 74 u32 handle; 75 u32 parent; 76 void *u32_node; 77 78 struct netdev_queue *dev_queue; 79 80 struct net_rate_estimator __rcu *rate_est; 81 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 82 struct gnet_stats_queue __percpu *cpu_qstats; 83 84 /* 85 * For performance sake on SMP, we put highly modified fields at the end 86 */ 87 struct sk_buff *gso_skb ____cacheline_aligned_in_smp; 88 struct qdisc_skb_head q; 89 struct gnet_stats_basic_packed bstats; 90 seqcount_t running; 91 struct gnet_stats_queue qstats; 92 unsigned long state; 93 struct Qdisc *next_sched; 94 struct sk_buff *skb_bad_txq; 95 struct rcu_head rcu_head; 96 int padded; 97 atomic_t refcnt; 98 99 spinlock_t busylock ____cacheline_aligned_in_smp; 100 }; 101 102 static inline bool qdisc_is_running(const struct Qdisc *qdisc) 103 { 104 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; 105 } 106 107 static inline bool qdisc_run_begin(struct Qdisc *qdisc) 108 { 109 if (qdisc_is_running(qdisc)) 110 return false; 111 /* Variant of write_seqcount_begin() telling lockdep a trylock 112 * was attempted. 113 */ 114 raw_write_seqcount_begin(&qdisc->running); 115 seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); 116 return true; 117 } 118 119 static inline void qdisc_run_end(struct Qdisc *qdisc) 120 { 121 write_seqcount_end(&qdisc->running); 122 } 123 124 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) 125 { 126 return qdisc->flags & TCQ_F_ONETXQUEUE; 127 } 128 129 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq) 130 { 131 #ifdef CONFIG_BQL 132 /* Non-BQL migrated drivers will return 0, too. */ 133 return dql_avail(&txq->dql); 134 #else 135 return 0; 136 #endif 137 } 138 139 struct Qdisc_class_ops { 140 /* Child qdisc manipulation */ 141 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *); 142 int (*graft)(struct Qdisc *, unsigned long cl, 143 struct Qdisc *, struct Qdisc **); 144 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl); 145 void (*qlen_notify)(struct Qdisc *, unsigned long); 146 147 /* Class manipulation routines */ 148 unsigned long (*get)(struct Qdisc *, u32 classid); 149 void (*put)(struct Qdisc *, unsigned long); 150 int (*change)(struct Qdisc *, u32, u32, 151 struct nlattr **, unsigned long *); 152 int (*delete)(struct Qdisc *, unsigned long); 153 void (*walk)(struct Qdisc *, struct qdisc_walker * arg); 154 155 /* Filter manipulation */ 156 struct tcf_proto __rcu ** (*tcf_chain)(struct Qdisc *, unsigned long); 157 bool (*tcf_cl_offload)(u32 classid); 158 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 159 u32 classid); 160 void (*unbind_tcf)(struct Qdisc *, unsigned long); 161 162 /* rtnetlink specific */ 163 int (*dump)(struct Qdisc *, unsigned long, 164 struct sk_buff *skb, struct tcmsg*); 165 int (*dump_stats)(struct Qdisc *, unsigned long, 166 struct gnet_dump *); 167 }; 168 169 struct Qdisc_ops { 170 struct Qdisc_ops *next; 171 const struct Qdisc_class_ops *cl_ops; 172 char id[IFNAMSIZ]; 173 int priv_size; 174 175 int (*enqueue)(struct sk_buff *skb, 176 struct Qdisc *sch, 177 struct sk_buff **to_free); 178 struct sk_buff * (*dequeue)(struct Qdisc *); 179 struct sk_buff * (*peek)(struct Qdisc *); 180 181 int (*init)(struct Qdisc *, struct nlattr *arg); 182 void (*reset)(struct Qdisc *); 183 void (*destroy)(struct Qdisc *); 184 int (*change)(struct Qdisc *, struct nlattr *arg); 185 void (*attach)(struct Qdisc *); 186 187 int (*dump)(struct Qdisc *, struct sk_buff *); 188 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 189 190 struct module *owner; 191 }; 192 193 194 struct tcf_result { 195 unsigned long class; 196 u32 classid; 197 }; 198 199 struct tcf_proto_ops { 200 struct list_head head; 201 char kind[IFNAMSIZ]; 202 203 int (*classify)(struct sk_buff *, 204 const struct tcf_proto *, 205 struct tcf_result *); 206 int (*init)(struct tcf_proto*); 207 void (*destroy)(struct tcf_proto*); 208 209 unsigned long (*get)(struct tcf_proto*, u32 handle); 210 int (*change)(struct net *net, struct sk_buff *, 211 struct tcf_proto*, unsigned long, 212 u32 handle, struct nlattr **, 213 unsigned long *, bool); 214 int (*delete)(struct tcf_proto*, unsigned long, bool*); 215 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 216 217 /* rtnetlink specific */ 218 int (*dump)(struct net*, struct tcf_proto*, unsigned long, 219 struct sk_buff *skb, struct tcmsg*); 220 221 struct module *owner; 222 }; 223 224 struct tcf_proto { 225 /* Fast access part */ 226 struct tcf_proto __rcu *next; 227 void __rcu *root; 228 int (*classify)(struct sk_buff *, 229 const struct tcf_proto *, 230 struct tcf_result *); 231 __be16 protocol; 232 233 /* All the rest */ 234 u32 prio; 235 u32 classid; 236 struct Qdisc *q; 237 void *data; 238 const struct tcf_proto_ops *ops; 239 struct rcu_head rcu; 240 }; 241 242 struct qdisc_skb_cb { 243 unsigned int pkt_len; 244 u16 slave_dev_queue_mapping; 245 u16 tc_classid; 246 #define QDISC_CB_PRIV_LEN 20 247 unsigned char data[QDISC_CB_PRIV_LEN]; 248 }; 249 250 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 251 { 252 struct qdisc_skb_cb *qcb; 253 254 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 255 BUILD_BUG_ON(sizeof(qcb->data) < sz); 256 } 257 258 static inline int qdisc_qlen(const struct Qdisc *q) 259 { 260 return q->q.qlen; 261 } 262 263 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 264 { 265 return (struct qdisc_skb_cb *)skb->cb; 266 } 267 268 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 269 { 270 return &qdisc->q.lock; 271 } 272 273 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 274 { 275 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 276 277 return q; 278 } 279 280 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 281 { 282 return qdisc->dev_queue->qdisc_sleeping; 283 } 284 285 /* The qdisc root lock is a mechanism by which to top level 286 * of a qdisc tree can be locked from any qdisc node in the 287 * forest. This allows changing the configuration of some 288 * aspect of the qdisc tree while blocking out asynchronous 289 * qdisc access in the packet processing paths. 290 * 291 * It is only legal to do this when the root will not change 292 * on us. Otherwise we'll potentially lock the wrong qdisc 293 * root. This is enforced by holding the RTNL semaphore, which 294 * all users of this lock accessor must do. 295 */ 296 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 297 { 298 struct Qdisc *root = qdisc_root(qdisc); 299 300 ASSERT_RTNL(); 301 return qdisc_lock(root); 302 } 303 304 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 305 { 306 struct Qdisc *root = qdisc_root_sleeping(qdisc); 307 308 ASSERT_RTNL(); 309 return qdisc_lock(root); 310 } 311 312 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 313 { 314 struct Qdisc *root = qdisc_root_sleeping(qdisc); 315 316 ASSERT_RTNL(); 317 return &root->running; 318 } 319 320 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 321 { 322 return qdisc->dev_queue->dev; 323 } 324 325 static inline void sch_tree_lock(const struct Qdisc *q) 326 { 327 spin_lock_bh(qdisc_root_sleeping_lock(q)); 328 } 329 330 static inline void sch_tree_unlock(const struct Qdisc *q) 331 { 332 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 333 } 334 335 #define tcf_tree_lock(tp) sch_tree_lock((tp)->q) 336 #define tcf_tree_unlock(tp) sch_tree_unlock((tp)->q) 337 338 extern struct Qdisc noop_qdisc; 339 extern struct Qdisc_ops noop_qdisc_ops; 340 extern struct Qdisc_ops pfifo_fast_ops; 341 extern struct Qdisc_ops mq_qdisc_ops; 342 extern struct Qdisc_ops noqueue_qdisc_ops; 343 extern const struct Qdisc_ops *default_qdisc_ops; 344 static inline const struct Qdisc_ops * 345 get_default_qdisc_ops(const struct net_device *dev, int ntx) 346 { 347 return ntx < dev->real_num_tx_queues ? 348 default_qdisc_ops : &pfifo_fast_ops; 349 } 350 351 struct Qdisc_class_common { 352 u32 classid; 353 struct hlist_node hnode; 354 }; 355 356 struct Qdisc_class_hash { 357 struct hlist_head *hash; 358 unsigned int hashsize; 359 unsigned int hashmask; 360 unsigned int hashelems; 361 }; 362 363 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 364 { 365 id ^= id >> 8; 366 id ^= id >> 4; 367 return id & mask; 368 } 369 370 static inline struct Qdisc_class_common * 371 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 372 { 373 struct Qdisc_class_common *cl; 374 unsigned int h; 375 376 h = qdisc_class_hash(id, hash->hashmask); 377 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 378 if (cl->classid == id) 379 return cl; 380 } 381 return NULL; 382 } 383 384 int qdisc_class_hash_init(struct Qdisc_class_hash *); 385 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 386 struct Qdisc_class_common *); 387 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 388 struct Qdisc_class_common *); 389 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 390 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 391 392 void dev_init_scheduler(struct net_device *dev); 393 void dev_shutdown(struct net_device *dev); 394 void dev_activate(struct net_device *dev); 395 void dev_deactivate(struct net_device *dev); 396 void dev_deactivate_many(struct list_head *head); 397 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 398 struct Qdisc *qdisc); 399 void qdisc_reset(struct Qdisc *qdisc); 400 void qdisc_destroy(struct Qdisc *qdisc); 401 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 402 unsigned int len); 403 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 404 const struct Qdisc_ops *ops); 405 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 406 const struct Qdisc_ops *ops, u32 parentid); 407 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 408 const struct qdisc_size_table *stab); 409 int skb_do_redirect(struct sk_buff *); 410 411 static inline void skb_reset_tc(struct sk_buff *skb) 412 { 413 #ifdef CONFIG_NET_CLS_ACT 414 skb->tc_redirected = 0; 415 #endif 416 } 417 418 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 419 { 420 #ifdef CONFIG_NET_CLS_ACT 421 return skb->tc_at_ingress; 422 #else 423 return false; 424 #endif 425 } 426 427 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 428 { 429 #ifdef CONFIG_NET_CLS_ACT 430 if (skb->tc_skip_classify) { 431 skb->tc_skip_classify = 0; 432 return true; 433 } 434 #endif 435 return false; 436 } 437 438 /* Reset all TX qdiscs greater then index of a device. */ 439 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 440 { 441 struct Qdisc *qdisc; 442 443 for (; i < dev->num_tx_queues; i++) { 444 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 445 if (qdisc) { 446 spin_lock_bh(qdisc_lock(qdisc)); 447 qdisc_reset(qdisc); 448 spin_unlock_bh(qdisc_lock(qdisc)); 449 } 450 } 451 } 452 453 static inline void qdisc_reset_all_tx(struct net_device *dev) 454 { 455 qdisc_reset_all_tx_gt(dev, 0); 456 } 457 458 /* Are all TX queues of the device empty? */ 459 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 460 { 461 unsigned int i; 462 463 rcu_read_lock(); 464 for (i = 0; i < dev->num_tx_queues; i++) { 465 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 466 const struct Qdisc *q = rcu_dereference(txq->qdisc); 467 468 if (q->q.qlen) { 469 rcu_read_unlock(); 470 return false; 471 } 472 } 473 rcu_read_unlock(); 474 return true; 475 } 476 477 /* Are any of the TX qdiscs changing? */ 478 static inline bool qdisc_tx_changing(const struct net_device *dev) 479 { 480 unsigned int i; 481 482 for (i = 0; i < dev->num_tx_queues; i++) { 483 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 484 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 485 return true; 486 } 487 return false; 488 } 489 490 /* Is the device using the noop qdisc on all queues? */ 491 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 492 { 493 unsigned int i; 494 495 for (i = 0; i < dev->num_tx_queues; i++) { 496 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 497 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 498 return false; 499 } 500 return true; 501 } 502 503 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 504 { 505 return qdisc_skb_cb(skb)->pkt_len; 506 } 507 508 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 509 enum net_xmit_qdisc_t { 510 __NET_XMIT_STOLEN = 0x00010000, 511 __NET_XMIT_BYPASS = 0x00020000, 512 }; 513 514 #ifdef CONFIG_NET_CLS_ACT 515 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 516 #else 517 #define net_xmit_drop_count(e) (1) 518 #endif 519 520 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 521 const struct Qdisc *sch) 522 { 523 #ifdef CONFIG_NET_SCHED 524 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 525 526 if (stab) 527 __qdisc_calculate_pkt_len(skb, stab); 528 #endif 529 } 530 531 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 532 struct sk_buff **to_free) 533 { 534 qdisc_calculate_pkt_len(skb, sch); 535 return sch->enqueue(skb, sch, to_free); 536 } 537 538 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 539 { 540 return q->flags & TCQ_F_CPUSTATS; 541 } 542 543 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 544 __u64 bytes, __u32 packets) 545 { 546 bstats->bytes += bytes; 547 bstats->packets += packets; 548 } 549 550 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 551 const struct sk_buff *skb) 552 { 553 _bstats_update(bstats, 554 qdisc_pkt_len(skb), 555 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 556 } 557 558 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 559 __u64 bytes, __u32 packets) 560 { 561 u64_stats_update_begin(&bstats->syncp); 562 _bstats_update(&bstats->bstats, bytes, packets); 563 u64_stats_update_end(&bstats->syncp); 564 } 565 566 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 567 const struct sk_buff *skb) 568 { 569 u64_stats_update_begin(&bstats->syncp); 570 bstats_update(&bstats->bstats, skb); 571 u64_stats_update_end(&bstats->syncp); 572 } 573 574 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 575 const struct sk_buff *skb) 576 { 577 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 578 } 579 580 static inline void qdisc_bstats_update(struct Qdisc *sch, 581 const struct sk_buff *skb) 582 { 583 bstats_update(&sch->bstats, skb); 584 } 585 586 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 587 const struct sk_buff *skb) 588 { 589 sch->qstats.backlog -= qdisc_pkt_len(skb); 590 } 591 592 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 593 const struct sk_buff *skb) 594 { 595 sch->qstats.backlog += qdisc_pkt_len(skb); 596 } 597 598 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 599 { 600 sch->qstats.drops += count; 601 } 602 603 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 604 { 605 qstats->drops++; 606 } 607 608 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 609 { 610 qstats->overlimits++; 611 } 612 613 static inline void qdisc_qstats_drop(struct Qdisc *sch) 614 { 615 qstats_drop_inc(&sch->qstats); 616 } 617 618 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 619 { 620 this_cpu_inc(sch->cpu_qstats->drops); 621 } 622 623 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 624 { 625 sch->qstats.overlimits++; 626 } 627 628 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 629 { 630 qh->head = NULL; 631 qh->tail = NULL; 632 qh->qlen = 0; 633 } 634 635 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 636 struct qdisc_skb_head *qh) 637 { 638 struct sk_buff *last = qh->tail; 639 640 if (last) { 641 skb->next = NULL; 642 last->next = skb; 643 qh->tail = skb; 644 } else { 645 qh->tail = skb; 646 qh->head = skb; 647 } 648 qh->qlen++; 649 qdisc_qstats_backlog_inc(sch, skb); 650 651 return NET_XMIT_SUCCESS; 652 } 653 654 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 655 { 656 return __qdisc_enqueue_tail(skb, sch, &sch->q); 657 } 658 659 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 660 { 661 struct sk_buff *skb = qh->head; 662 663 if (likely(skb != NULL)) { 664 qh->head = skb->next; 665 qh->qlen--; 666 if (qh->head == NULL) 667 qh->tail = NULL; 668 skb->next = NULL; 669 } 670 671 return skb; 672 } 673 674 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 675 { 676 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 677 678 if (likely(skb != NULL)) { 679 qdisc_qstats_backlog_dec(sch, skb); 680 qdisc_bstats_update(sch, skb); 681 } 682 683 return skb; 684 } 685 686 /* Instead of calling kfree_skb() while root qdisc lock is held, 687 * queue the skb for future freeing at end of __dev_xmit_skb() 688 */ 689 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 690 { 691 skb->next = *to_free; 692 *to_free = skb; 693 } 694 695 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 696 struct qdisc_skb_head *qh, 697 struct sk_buff **to_free) 698 { 699 struct sk_buff *skb = __qdisc_dequeue_head(qh); 700 701 if (likely(skb != NULL)) { 702 unsigned int len = qdisc_pkt_len(skb); 703 704 qdisc_qstats_backlog_dec(sch, skb); 705 __qdisc_drop(skb, to_free); 706 return len; 707 } 708 709 return 0; 710 } 711 712 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 713 struct sk_buff **to_free) 714 { 715 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 716 } 717 718 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 719 { 720 const struct qdisc_skb_head *qh = &sch->q; 721 722 return qh->head; 723 } 724 725 /* generic pseudo peek method for non-work-conserving qdisc */ 726 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 727 { 728 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 729 if (!sch->gso_skb) { 730 sch->gso_skb = sch->dequeue(sch); 731 if (sch->gso_skb) { 732 /* it's still part of the queue */ 733 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 734 sch->q.qlen++; 735 } 736 } 737 738 return sch->gso_skb; 739 } 740 741 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 742 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 743 { 744 struct sk_buff *skb = sch->gso_skb; 745 746 if (skb) { 747 sch->gso_skb = NULL; 748 qdisc_qstats_backlog_dec(sch, skb); 749 sch->q.qlen--; 750 } else { 751 skb = sch->dequeue(sch); 752 } 753 754 return skb; 755 } 756 757 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 758 { 759 /* 760 * We do not know the backlog in bytes of this list, it 761 * is up to the caller to correct it 762 */ 763 ASSERT_RTNL(); 764 if (qh->qlen) { 765 rtnl_kfree_skbs(qh->head, qh->tail); 766 767 qh->head = NULL; 768 qh->tail = NULL; 769 qh->qlen = 0; 770 } 771 } 772 773 static inline void qdisc_reset_queue(struct Qdisc *sch) 774 { 775 __qdisc_reset_queue(&sch->q); 776 sch->qstats.backlog = 0; 777 } 778 779 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 780 struct Qdisc **pold) 781 { 782 struct Qdisc *old; 783 784 sch_tree_lock(sch); 785 old = *pold; 786 *pold = new; 787 if (old != NULL) { 788 qdisc_tree_reduce_backlog(old, old->q.qlen, old->qstats.backlog); 789 qdisc_reset(old); 790 } 791 sch_tree_unlock(sch); 792 793 return old; 794 } 795 796 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 797 { 798 rtnl_kfree_skbs(skb, skb); 799 qdisc_qstats_drop(sch); 800 } 801 802 803 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 804 struct sk_buff **to_free) 805 { 806 __qdisc_drop(skb, to_free); 807 qdisc_qstats_drop(sch); 808 809 return NET_XMIT_DROP; 810 } 811 812 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 813 long it will take to send a packet given its size. 814 */ 815 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 816 { 817 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 818 if (slot < 0) 819 slot = 0; 820 slot >>= rtab->rate.cell_log; 821 if (slot > 255) 822 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 823 return rtab->data[slot]; 824 } 825 826 struct psched_ratecfg { 827 u64 rate_bytes_ps; /* bytes per second */ 828 u32 mult; 829 u16 overhead; 830 u8 linklayer; 831 u8 shift; 832 }; 833 834 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 835 unsigned int len) 836 { 837 len += r->overhead; 838 839 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 840 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 841 842 return ((u64)len * r->mult) >> r->shift; 843 } 844 845 void psched_ratecfg_precompute(struct psched_ratecfg *r, 846 const struct tc_ratespec *conf, 847 u64 rate64); 848 849 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 850 const struct psched_ratecfg *r) 851 { 852 memset(res, 0, sizeof(*res)); 853 854 /* legacy struct tc_ratespec has a 32bit @rate field 855 * Qdisc using 64bit rate should add new attributes 856 * in order to maintain compatibility. 857 */ 858 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 859 860 res->overhead = r->overhead; 861 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 862 } 863 864 #endif 865