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 void *u32_node; 79 80 struct netdev_queue *dev_queue; 81 82 struct net_rate_estimator __rcu *rate_est; 83 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 84 struct gnet_stats_queue __percpu *cpu_qstats; 85 86 /* 87 * For performance sake on SMP, we put highly modified fields at the end 88 */ 89 struct sk_buff *gso_skb ____cacheline_aligned_in_smp; 90 struct qdisc_skb_head q; 91 struct gnet_stats_basic_packed bstats; 92 seqcount_t running; 93 struct gnet_stats_queue qstats; 94 unsigned long state; 95 struct Qdisc *next_sched; 96 struct sk_buff *skb_bad_txq; 97 struct rcu_head rcu_head; 98 int padded; 99 refcount_t refcnt; 100 101 spinlock_t busylock ____cacheline_aligned_in_smp; 102 }; 103 104 static inline void qdisc_refcount_inc(struct Qdisc *qdisc) 105 { 106 if (qdisc->flags & TCQ_F_BUILTIN) 107 return; 108 refcount_inc(&qdisc->refcnt); 109 } 110 111 static inline bool qdisc_is_running(const struct Qdisc *qdisc) 112 { 113 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; 114 } 115 116 static inline bool qdisc_run_begin(struct Qdisc *qdisc) 117 { 118 if (qdisc_is_running(qdisc)) 119 return false; 120 /* Variant of write_seqcount_begin() telling lockdep a trylock 121 * was attempted. 122 */ 123 raw_write_seqcount_begin(&qdisc->running); 124 seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); 125 return true; 126 } 127 128 static inline void qdisc_run_end(struct Qdisc *qdisc) 129 { 130 write_seqcount_end(&qdisc->running); 131 } 132 133 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) 134 { 135 return qdisc->flags & TCQ_F_ONETXQUEUE; 136 } 137 138 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq) 139 { 140 #ifdef CONFIG_BQL 141 /* Non-BQL migrated drivers will return 0, too. */ 142 return dql_avail(&txq->dql); 143 #else 144 return 0; 145 #endif 146 } 147 148 struct Qdisc_class_ops { 149 /* Child qdisc manipulation */ 150 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *); 151 int (*graft)(struct Qdisc *, unsigned long cl, 152 struct Qdisc *, struct Qdisc **); 153 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl); 154 void (*qlen_notify)(struct Qdisc *, unsigned long); 155 156 /* Class manipulation routines */ 157 unsigned long (*get)(struct Qdisc *, u32 classid); 158 void (*put)(struct Qdisc *, unsigned long); 159 int (*change)(struct Qdisc *, u32, u32, 160 struct nlattr **, unsigned long *); 161 int (*delete)(struct Qdisc *, unsigned long); 162 void (*walk)(struct Qdisc *, struct qdisc_walker * arg); 163 164 /* Filter manipulation */ 165 struct tcf_block * (*tcf_block)(struct Qdisc *, unsigned long); 166 bool (*tcf_cl_offload)(u32 classid); 167 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 168 u32 classid); 169 void (*unbind_tcf)(struct Qdisc *, unsigned long); 170 171 /* rtnetlink specific */ 172 int (*dump)(struct Qdisc *, unsigned long, 173 struct sk_buff *skb, struct tcmsg*); 174 int (*dump_stats)(struct Qdisc *, unsigned long, 175 struct gnet_dump *); 176 }; 177 178 struct Qdisc_ops { 179 struct Qdisc_ops *next; 180 const struct Qdisc_class_ops *cl_ops; 181 char id[IFNAMSIZ]; 182 int priv_size; 183 184 int (*enqueue)(struct sk_buff *skb, 185 struct Qdisc *sch, 186 struct sk_buff **to_free); 187 struct sk_buff * (*dequeue)(struct Qdisc *); 188 struct sk_buff * (*peek)(struct Qdisc *); 189 190 int (*init)(struct Qdisc *, struct nlattr *arg); 191 void (*reset)(struct Qdisc *); 192 void (*destroy)(struct Qdisc *); 193 int (*change)(struct Qdisc *, struct nlattr *arg); 194 void (*attach)(struct Qdisc *); 195 196 int (*dump)(struct Qdisc *, struct sk_buff *); 197 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 198 199 struct module *owner; 200 }; 201 202 203 struct tcf_result { 204 union { 205 struct { 206 unsigned long class; 207 u32 classid; 208 }; 209 const struct tcf_proto *goto_tp; 210 }; 211 }; 212 213 struct tcf_proto_ops { 214 struct list_head head; 215 char kind[IFNAMSIZ]; 216 217 int (*classify)(struct sk_buff *, 218 const struct tcf_proto *, 219 struct tcf_result *); 220 int (*init)(struct tcf_proto*); 221 void (*destroy)(struct tcf_proto*); 222 223 unsigned long (*get)(struct tcf_proto*, u32 handle); 224 int (*change)(struct net *net, struct sk_buff *, 225 struct tcf_proto*, unsigned long, 226 u32 handle, struct nlattr **, 227 unsigned long *, bool); 228 int (*delete)(struct tcf_proto*, unsigned long, bool*); 229 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 230 231 /* rtnetlink specific */ 232 int (*dump)(struct net*, struct tcf_proto*, unsigned long, 233 struct sk_buff *skb, struct tcmsg*); 234 235 struct module *owner; 236 }; 237 238 struct tcf_proto { 239 /* Fast access part */ 240 struct tcf_proto __rcu *next; 241 void __rcu *root; 242 int (*classify)(struct sk_buff *, 243 const struct tcf_proto *, 244 struct tcf_result *); 245 __be16 protocol; 246 247 /* All the rest */ 248 u32 prio; 249 u32 classid; 250 struct Qdisc *q; 251 void *data; 252 const struct tcf_proto_ops *ops; 253 struct tcf_chain *chain; 254 struct rcu_head rcu; 255 }; 256 257 struct qdisc_skb_cb { 258 unsigned int pkt_len; 259 u16 slave_dev_queue_mapping; 260 u16 tc_classid; 261 #define QDISC_CB_PRIV_LEN 20 262 unsigned char data[QDISC_CB_PRIV_LEN]; 263 }; 264 265 struct tcf_chain { 266 struct tcf_proto __rcu *filter_chain; 267 struct tcf_proto __rcu **p_filter_chain; 268 struct list_head list; 269 struct tcf_block *block; 270 u32 index; /* chain index */ 271 unsigned int refcnt; 272 }; 273 274 struct tcf_block { 275 struct list_head chain_list; 276 }; 277 278 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 279 { 280 struct qdisc_skb_cb *qcb; 281 282 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 283 BUILD_BUG_ON(sizeof(qcb->data) < sz); 284 } 285 286 static inline int qdisc_qlen(const struct Qdisc *q) 287 { 288 return q->q.qlen; 289 } 290 291 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 292 { 293 return (struct qdisc_skb_cb *)skb->cb; 294 } 295 296 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 297 { 298 return &qdisc->q.lock; 299 } 300 301 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 302 { 303 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 304 305 return q; 306 } 307 308 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 309 { 310 return qdisc->dev_queue->qdisc_sleeping; 311 } 312 313 /* The qdisc root lock is a mechanism by which to top level 314 * of a qdisc tree can be locked from any qdisc node in the 315 * forest. This allows changing the configuration of some 316 * aspect of the qdisc tree while blocking out asynchronous 317 * qdisc access in the packet processing paths. 318 * 319 * It is only legal to do this when the root will not change 320 * on us. Otherwise we'll potentially lock the wrong qdisc 321 * root. This is enforced by holding the RTNL semaphore, which 322 * all users of this lock accessor must do. 323 */ 324 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 325 { 326 struct Qdisc *root = qdisc_root(qdisc); 327 328 ASSERT_RTNL(); 329 return qdisc_lock(root); 330 } 331 332 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 333 { 334 struct Qdisc *root = qdisc_root_sleeping(qdisc); 335 336 ASSERT_RTNL(); 337 return qdisc_lock(root); 338 } 339 340 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 341 { 342 struct Qdisc *root = qdisc_root_sleeping(qdisc); 343 344 ASSERT_RTNL(); 345 return &root->running; 346 } 347 348 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 349 { 350 return qdisc->dev_queue->dev; 351 } 352 353 static inline void sch_tree_lock(const struct Qdisc *q) 354 { 355 spin_lock_bh(qdisc_root_sleeping_lock(q)); 356 } 357 358 static inline void sch_tree_unlock(const struct Qdisc *q) 359 { 360 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 361 } 362 363 #define tcf_tree_lock(tp) sch_tree_lock((tp)->q) 364 #define tcf_tree_unlock(tp) sch_tree_unlock((tp)->q) 365 366 extern struct Qdisc noop_qdisc; 367 extern struct Qdisc_ops noop_qdisc_ops; 368 extern struct Qdisc_ops pfifo_fast_ops; 369 extern struct Qdisc_ops mq_qdisc_ops; 370 extern struct Qdisc_ops noqueue_qdisc_ops; 371 extern const struct Qdisc_ops *default_qdisc_ops; 372 static inline const struct Qdisc_ops * 373 get_default_qdisc_ops(const struct net_device *dev, int ntx) 374 { 375 return ntx < dev->real_num_tx_queues ? 376 default_qdisc_ops : &pfifo_fast_ops; 377 } 378 379 struct Qdisc_class_common { 380 u32 classid; 381 struct hlist_node hnode; 382 }; 383 384 struct Qdisc_class_hash { 385 struct hlist_head *hash; 386 unsigned int hashsize; 387 unsigned int hashmask; 388 unsigned int hashelems; 389 }; 390 391 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 392 { 393 id ^= id >> 8; 394 id ^= id >> 4; 395 return id & mask; 396 } 397 398 static inline struct Qdisc_class_common * 399 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 400 { 401 struct Qdisc_class_common *cl; 402 unsigned int h; 403 404 h = qdisc_class_hash(id, hash->hashmask); 405 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 406 if (cl->classid == id) 407 return cl; 408 } 409 return NULL; 410 } 411 412 int qdisc_class_hash_init(struct Qdisc_class_hash *); 413 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 414 struct Qdisc_class_common *); 415 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 416 struct Qdisc_class_common *); 417 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 418 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 419 420 void dev_init_scheduler(struct net_device *dev); 421 void dev_shutdown(struct net_device *dev); 422 void dev_activate(struct net_device *dev); 423 void dev_deactivate(struct net_device *dev); 424 void dev_deactivate_many(struct list_head *head); 425 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 426 struct Qdisc *qdisc); 427 void qdisc_reset(struct Qdisc *qdisc); 428 void qdisc_destroy(struct Qdisc *qdisc); 429 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 430 unsigned int len); 431 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 432 const struct Qdisc_ops *ops); 433 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 434 const struct Qdisc_ops *ops, u32 parentid); 435 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 436 const struct qdisc_size_table *stab); 437 int skb_do_redirect(struct sk_buff *); 438 439 static inline void skb_reset_tc(struct sk_buff *skb) 440 { 441 #ifdef CONFIG_NET_CLS_ACT 442 skb->tc_redirected = 0; 443 #endif 444 } 445 446 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 447 { 448 #ifdef CONFIG_NET_CLS_ACT 449 return skb->tc_at_ingress; 450 #else 451 return false; 452 #endif 453 } 454 455 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 456 { 457 #ifdef CONFIG_NET_CLS_ACT 458 if (skb->tc_skip_classify) { 459 skb->tc_skip_classify = 0; 460 return true; 461 } 462 #endif 463 return false; 464 } 465 466 /* Reset all TX qdiscs greater then index of a device. */ 467 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 468 { 469 struct Qdisc *qdisc; 470 471 for (; i < dev->num_tx_queues; i++) { 472 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 473 if (qdisc) { 474 spin_lock_bh(qdisc_lock(qdisc)); 475 qdisc_reset(qdisc); 476 spin_unlock_bh(qdisc_lock(qdisc)); 477 } 478 } 479 } 480 481 static inline void qdisc_reset_all_tx(struct net_device *dev) 482 { 483 qdisc_reset_all_tx_gt(dev, 0); 484 } 485 486 /* Are all TX queues of the device empty? */ 487 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 488 { 489 unsigned int i; 490 491 rcu_read_lock(); 492 for (i = 0; i < dev->num_tx_queues; i++) { 493 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 494 const struct Qdisc *q = rcu_dereference(txq->qdisc); 495 496 if (q->q.qlen) { 497 rcu_read_unlock(); 498 return false; 499 } 500 } 501 rcu_read_unlock(); 502 return true; 503 } 504 505 /* Are any of the TX qdiscs changing? */ 506 static inline bool qdisc_tx_changing(const struct net_device *dev) 507 { 508 unsigned int i; 509 510 for (i = 0; i < dev->num_tx_queues; i++) { 511 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 512 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 513 return true; 514 } 515 return false; 516 } 517 518 /* Is the device using the noop qdisc on all queues? */ 519 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 520 { 521 unsigned int i; 522 523 for (i = 0; i < dev->num_tx_queues; i++) { 524 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 525 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 526 return false; 527 } 528 return true; 529 } 530 531 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 532 { 533 return qdisc_skb_cb(skb)->pkt_len; 534 } 535 536 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 537 enum net_xmit_qdisc_t { 538 __NET_XMIT_STOLEN = 0x00010000, 539 __NET_XMIT_BYPASS = 0x00020000, 540 }; 541 542 #ifdef CONFIG_NET_CLS_ACT 543 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 544 #else 545 #define net_xmit_drop_count(e) (1) 546 #endif 547 548 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 549 const struct Qdisc *sch) 550 { 551 #ifdef CONFIG_NET_SCHED 552 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 553 554 if (stab) 555 __qdisc_calculate_pkt_len(skb, stab); 556 #endif 557 } 558 559 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 560 struct sk_buff **to_free) 561 { 562 qdisc_calculate_pkt_len(skb, sch); 563 return sch->enqueue(skb, sch, to_free); 564 } 565 566 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 567 { 568 return q->flags & TCQ_F_CPUSTATS; 569 } 570 571 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 572 __u64 bytes, __u32 packets) 573 { 574 bstats->bytes += bytes; 575 bstats->packets += packets; 576 } 577 578 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 579 const struct sk_buff *skb) 580 { 581 _bstats_update(bstats, 582 qdisc_pkt_len(skb), 583 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 584 } 585 586 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 587 __u64 bytes, __u32 packets) 588 { 589 u64_stats_update_begin(&bstats->syncp); 590 _bstats_update(&bstats->bstats, bytes, packets); 591 u64_stats_update_end(&bstats->syncp); 592 } 593 594 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 595 const struct sk_buff *skb) 596 { 597 u64_stats_update_begin(&bstats->syncp); 598 bstats_update(&bstats->bstats, skb); 599 u64_stats_update_end(&bstats->syncp); 600 } 601 602 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 603 const struct sk_buff *skb) 604 { 605 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 606 } 607 608 static inline void qdisc_bstats_update(struct Qdisc *sch, 609 const struct sk_buff *skb) 610 { 611 bstats_update(&sch->bstats, skb); 612 } 613 614 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 615 const struct sk_buff *skb) 616 { 617 sch->qstats.backlog -= qdisc_pkt_len(skb); 618 } 619 620 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 621 const struct sk_buff *skb) 622 { 623 sch->qstats.backlog += qdisc_pkt_len(skb); 624 } 625 626 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 627 { 628 sch->qstats.drops += count; 629 } 630 631 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 632 { 633 qstats->drops++; 634 } 635 636 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 637 { 638 qstats->overlimits++; 639 } 640 641 static inline void qdisc_qstats_drop(struct Qdisc *sch) 642 { 643 qstats_drop_inc(&sch->qstats); 644 } 645 646 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 647 { 648 this_cpu_inc(sch->cpu_qstats->drops); 649 } 650 651 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 652 { 653 sch->qstats.overlimits++; 654 } 655 656 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 657 { 658 qh->head = NULL; 659 qh->tail = NULL; 660 qh->qlen = 0; 661 } 662 663 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 664 struct qdisc_skb_head *qh) 665 { 666 struct sk_buff *last = qh->tail; 667 668 if (last) { 669 skb->next = NULL; 670 last->next = skb; 671 qh->tail = skb; 672 } else { 673 qh->tail = skb; 674 qh->head = skb; 675 } 676 qh->qlen++; 677 qdisc_qstats_backlog_inc(sch, skb); 678 679 return NET_XMIT_SUCCESS; 680 } 681 682 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 683 { 684 return __qdisc_enqueue_tail(skb, sch, &sch->q); 685 } 686 687 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 688 { 689 struct sk_buff *skb = qh->head; 690 691 if (likely(skb != NULL)) { 692 qh->head = skb->next; 693 qh->qlen--; 694 if (qh->head == NULL) 695 qh->tail = NULL; 696 skb->next = NULL; 697 } 698 699 return skb; 700 } 701 702 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 703 { 704 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 705 706 if (likely(skb != NULL)) { 707 qdisc_qstats_backlog_dec(sch, skb); 708 qdisc_bstats_update(sch, skb); 709 } 710 711 return skb; 712 } 713 714 /* Instead of calling kfree_skb() while root qdisc lock is held, 715 * queue the skb for future freeing at end of __dev_xmit_skb() 716 */ 717 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 718 { 719 skb->next = *to_free; 720 *to_free = skb; 721 } 722 723 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 724 struct qdisc_skb_head *qh, 725 struct sk_buff **to_free) 726 { 727 struct sk_buff *skb = __qdisc_dequeue_head(qh); 728 729 if (likely(skb != NULL)) { 730 unsigned int len = qdisc_pkt_len(skb); 731 732 qdisc_qstats_backlog_dec(sch, skb); 733 __qdisc_drop(skb, to_free); 734 return len; 735 } 736 737 return 0; 738 } 739 740 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 741 struct sk_buff **to_free) 742 { 743 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 744 } 745 746 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 747 { 748 const struct qdisc_skb_head *qh = &sch->q; 749 750 return qh->head; 751 } 752 753 /* generic pseudo peek method for non-work-conserving qdisc */ 754 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 755 { 756 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 757 if (!sch->gso_skb) { 758 sch->gso_skb = sch->dequeue(sch); 759 if (sch->gso_skb) { 760 /* it's still part of the queue */ 761 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 762 sch->q.qlen++; 763 } 764 } 765 766 return sch->gso_skb; 767 } 768 769 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 770 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 771 { 772 struct sk_buff *skb = sch->gso_skb; 773 774 if (skb) { 775 sch->gso_skb = NULL; 776 qdisc_qstats_backlog_dec(sch, skb); 777 sch->q.qlen--; 778 } else { 779 skb = sch->dequeue(sch); 780 } 781 782 return skb; 783 } 784 785 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 786 { 787 /* 788 * We do not know the backlog in bytes of this list, it 789 * is up to the caller to correct it 790 */ 791 ASSERT_RTNL(); 792 if (qh->qlen) { 793 rtnl_kfree_skbs(qh->head, qh->tail); 794 795 qh->head = NULL; 796 qh->tail = NULL; 797 qh->qlen = 0; 798 } 799 } 800 801 static inline void qdisc_reset_queue(struct Qdisc *sch) 802 { 803 __qdisc_reset_queue(&sch->q); 804 sch->qstats.backlog = 0; 805 } 806 807 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 808 struct Qdisc **pold) 809 { 810 struct Qdisc *old; 811 812 sch_tree_lock(sch); 813 old = *pold; 814 *pold = new; 815 if (old != NULL) { 816 unsigned int qlen = old->q.qlen; 817 unsigned int backlog = old->qstats.backlog; 818 819 qdisc_reset(old); 820 qdisc_tree_reduce_backlog(old, qlen, backlog); 821 } 822 sch_tree_unlock(sch); 823 824 return old; 825 } 826 827 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 828 { 829 rtnl_kfree_skbs(skb, skb); 830 qdisc_qstats_drop(sch); 831 } 832 833 834 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 835 struct sk_buff **to_free) 836 { 837 __qdisc_drop(skb, to_free); 838 qdisc_qstats_drop(sch); 839 840 return NET_XMIT_DROP; 841 } 842 843 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 844 long it will take to send a packet given its size. 845 */ 846 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 847 { 848 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 849 if (slot < 0) 850 slot = 0; 851 slot >>= rtab->rate.cell_log; 852 if (slot > 255) 853 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 854 return rtab->data[slot]; 855 } 856 857 struct psched_ratecfg { 858 u64 rate_bytes_ps; /* bytes per second */ 859 u32 mult; 860 u16 overhead; 861 u8 linklayer; 862 u8 shift; 863 }; 864 865 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 866 unsigned int len) 867 { 868 len += r->overhead; 869 870 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 871 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 872 873 return ((u64)len * r->mult) >> r->shift; 874 } 875 876 void psched_ratecfg_precompute(struct psched_ratecfg *r, 877 const struct tc_ratespec *conf, 878 u64 rate64); 879 880 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 881 const struct psched_ratecfg *r) 882 { 883 memset(res, 0, sizeof(*res)); 884 885 /* legacy struct tc_ratespec has a 32bit @rate field 886 * Qdisc using 64bit rate should add new attributes 887 * in order to maintain compatibility. 888 */ 889 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 890 891 res->overhead = r->overhead; 892 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 893 } 894 895 #endif 896