1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_SCHED_GENERIC_H 3 #define __NET_SCHED_GENERIC_H 4 5 #include <linux/netdevice.h> 6 #include <linux/types.h> 7 #include <linux/rcupdate.h> 8 #include <linux/pkt_sched.h> 9 #include <linux/pkt_cls.h> 10 #include <linux/percpu.h> 11 #include <linux/dynamic_queue_limits.h> 12 #include <linux/list.h> 13 #include <linux/refcount.h> 14 #include <linux/workqueue.h> 15 #include <net/gen_stats.h> 16 #include <net/rtnetlink.h> 17 18 struct Qdisc_ops; 19 struct qdisc_walker; 20 struct tcf_walker; 21 struct module; 22 23 struct qdisc_rate_table { 24 struct tc_ratespec rate; 25 u32 data[256]; 26 struct qdisc_rate_table *next; 27 int refcnt; 28 }; 29 30 enum qdisc_state_t { 31 __QDISC_STATE_SCHED, 32 __QDISC_STATE_DEACTIVATED, 33 }; 34 35 struct qdisc_size_table { 36 struct rcu_head rcu; 37 struct list_head list; 38 struct tc_sizespec szopts; 39 int refcnt; 40 u16 data[]; 41 }; 42 43 /* similar to sk_buff_head, but skb->prev pointer is undefined. */ 44 struct qdisc_skb_head { 45 struct sk_buff *head; 46 struct sk_buff *tail; 47 __u32 qlen; 48 spinlock_t lock; 49 }; 50 51 struct Qdisc { 52 int (*enqueue)(struct sk_buff *skb, 53 struct Qdisc *sch, 54 struct sk_buff **to_free); 55 struct sk_buff * (*dequeue)(struct Qdisc *sch); 56 unsigned int flags; 57 #define TCQ_F_BUILTIN 1 58 #define TCQ_F_INGRESS 2 59 #define TCQ_F_CAN_BYPASS 4 60 #define TCQ_F_MQROOT 8 61 #define TCQ_F_ONETXQUEUE 0x10 /* dequeue_skb() can assume all skbs are for 62 * q->dev_queue : It can test 63 * netif_xmit_frozen_or_stopped() before 64 * dequeueing next packet. 65 * Its true for MQ/MQPRIO slaves, or non 66 * multiqueue device. 67 */ 68 #define TCQ_F_WARN_NONWC (1 << 16) 69 #define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */ 70 #define TCQ_F_NOPARENT 0x40 /* root of its hierarchy : 71 * qdisc_tree_decrease_qlen() should stop. 72 */ 73 #define TCQ_F_INVISIBLE 0x80 /* invisible by default in dump */ 74 u32 limit; 75 const struct Qdisc_ops *ops; 76 struct qdisc_size_table __rcu *stab; 77 struct hlist_node hash; 78 u32 handle; 79 u32 parent; 80 81 struct netdev_queue *dev_queue; 82 83 struct net_rate_estimator __rcu *rate_est; 84 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 85 struct gnet_stats_queue __percpu *cpu_qstats; 86 87 /* 88 * For performance sake on SMP, we put highly modified fields at the end 89 */ 90 struct sk_buff *gso_skb ____cacheline_aligned_in_smp; 91 struct qdisc_skb_head q; 92 struct gnet_stats_basic_packed bstats; 93 seqcount_t running; 94 struct gnet_stats_queue qstats; 95 unsigned long state; 96 struct Qdisc *next_sched; 97 struct sk_buff *skb_bad_txq; 98 struct rcu_head rcu_head; 99 int padded; 100 refcount_t refcnt; 101 102 spinlock_t busylock ____cacheline_aligned_in_smp; 103 }; 104 105 static inline void qdisc_refcount_inc(struct Qdisc *qdisc) 106 { 107 if (qdisc->flags & TCQ_F_BUILTIN) 108 return; 109 refcount_inc(&qdisc->refcnt); 110 } 111 112 static inline bool qdisc_is_running(const struct Qdisc *qdisc) 113 { 114 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; 115 } 116 117 static inline bool qdisc_run_begin(struct Qdisc *qdisc) 118 { 119 if (qdisc_is_running(qdisc)) 120 return false; 121 /* Variant of write_seqcount_begin() telling lockdep a trylock 122 * was attempted. 123 */ 124 raw_write_seqcount_begin(&qdisc->running); 125 seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); 126 return true; 127 } 128 129 static inline void qdisc_run_end(struct Qdisc *qdisc) 130 { 131 write_seqcount_end(&qdisc->running); 132 } 133 134 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) 135 { 136 return qdisc->flags & TCQ_F_ONETXQUEUE; 137 } 138 139 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq) 140 { 141 #ifdef CONFIG_BQL 142 /* Non-BQL migrated drivers will return 0, too. */ 143 return dql_avail(&txq->dql); 144 #else 145 return 0; 146 #endif 147 } 148 149 struct Qdisc_class_ops { 150 /* Child qdisc manipulation */ 151 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *); 152 int (*graft)(struct Qdisc *, unsigned long cl, 153 struct Qdisc *, struct Qdisc **); 154 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl); 155 void (*qlen_notify)(struct Qdisc *, unsigned long); 156 157 /* Class manipulation routines */ 158 unsigned long (*find)(struct Qdisc *, u32 classid); 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 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 167 u32 classid); 168 void (*unbind_tcf)(struct Qdisc *, unsigned long); 169 170 /* rtnetlink specific */ 171 int (*dump)(struct Qdisc *, unsigned long, 172 struct sk_buff *skb, struct tcmsg*); 173 int (*dump_stats)(struct Qdisc *, unsigned long, 174 struct gnet_dump *); 175 }; 176 177 struct Qdisc_ops { 178 struct Qdisc_ops *next; 179 const struct Qdisc_class_ops *cl_ops; 180 char id[IFNAMSIZ]; 181 int priv_size; 182 183 int (*enqueue)(struct sk_buff *skb, 184 struct Qdisc *sch, 185 struct sk_buff **to_free); 186 struct sk_buff * (*dequeue)(struct Qdisc *); 187 struct sk_buff * (*peek)(struct Qdisc *); 188 189 int (*init)(struct Qdisc *, struct nlattr *arg); 190 void (*reset)(struct Qdisc *); 191 void (*destroy)(struct Qdisc *); 192 int (*change)(struct Qdisc *, struct nlattr *arg); 193 void (*attach)(struct Qdisc *); 194 195 int (*dump)(struct Qdisc *, struct sk_buff *); 196 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 197 198 struct module *owner; 199 }; 200 201 202 struct tcf_result { 203 union { 204 struct { 205 unsigned long class; 206 u32 classid; 207 }; 208 const struct tcf_proto *goto_tp; 209 }; 210 }; 211 212 struct tcf_proto_ops { 213 struct list_head head; 214 char kind[IFNAMSIZ]; 215 216 int (*classify)(struct sk_buff *, 217 const struct tcf_proto *, 218 struct tcf_result *); 219 int (*init)(struct tcf_proto*); 220 void (*destroy)(struct tcf_proto*); 221 222 void* (*get)(struct tcf_proto*, u32 handle); 223 int (*change)(struct net *net, struct sk_buff *, 224 struct tcf_proto*, unsigned long, 225 u32 handle, struct nlattr **, 226 void **, bool); 227 int (*delete)(struct tcf_proto*, void *, bool*); 228 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 229 void (*bind_class)(void *, u32, unsigned long); 230 231 /* rtnetlink specific */ 232 int (*dump)(struct net*, struct tcf_proto*, void *, 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 struct work_struct work; 277 }; 278 279 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 280 { 281 struct qdisc_skb_cb *qcb; 282 283 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 284 BUILD_BUG_ON(sizeof(qcb->data) < sz); 285 } 286 287 static inline int qdisc_qlen(const struct Qdisc *q) 288 { 289 return q->q.qlen; 290 } 291 292 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 293 { 294 return (struct qdisc_skb_cb *)skb->cb; 295 } 296 297 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 298 { 299 return &qdisc->q.lock; 300 } 301 302 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 303 { 304 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 305 306 return q; 307 } 308 309 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 310 { 311 return qdisc->dev_queue->qdisc_sleeping; 312 } 313 314 /* The qdisc root lock is a mechanism by which to top level 315 * of a qdisc tree can be locked from any qdisc node in the 316 * forest. This allows changing the configuration of some 317 * aspect of the qdisc tree while blocking out asynchronous 318 * qdisc access in the packet processing paths. 319 * 320 * It is only legal to do this when the root will not change 321 * on us. Otherwise we'll potentially lock the wrong qdisc 322 * root. This is enforced by holding the RTNL semaphore, which 323 * all users of this lock accessor must do. 324 */ 325 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 326 { 327 struct Qdisc *root = qdisc_root(qdisc); 328 329 ASSERT_RTNL(); 330 return qdisc_lock(root); 331 } 332 333 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 334 { 335 struct Qdisc *root = qdisc_root_sleeping(qdisc); 336 337 ASSERT_RTNL(); 338 return qdisc_lock(root); 339 } 340 341 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 342 { 343 struct Qdisc *root = qdisc_root_sleeping(qdisc); 344 345 ASSERT_RTNL(); 346 return &root->running; 347 } 348 349 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 350 { 351 return qdisc->dev_queue->dev; 352 } 353 354 static inline void sch_tree_lock(const struct Qdisc *q) 355 { 356 spin_lock_bh(qdisc_root_sleeping_lock(q)); 357 } 358 359 static inline void sch_tree_unlock(const struct Qdisc *q) 360 { 361 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 362 } 363 364 #define tcf_tree_lock(tp) sch_tree_lock((tp)->q) 365 #define tcf_tree_unlock(tp) sch_tree_unlock((tp)->q) 366 367 extern struct Qdisc noop_qdisc; 368 extern struct Qdisc_ops noop_qdisc_ops; 369 extern struct Qdisc_ops pfifo_fast_ops; 370 extern struct Qdisc_ops mq_qdisc_ops; 371 extern struct Qdisc_ops noqueue_qdisc_ops; 372 extern const struct Qdisc_ops *default_qdisc_ops; 373 static inline const struct Qdisc_ops * 374 get_default_qdisc_ops(const struct net_device *dev, int ntx) 375 { 376 return ntx < dev->real_num_tx_queues ? 377 default_qdisc_ops : &pfifo_fast_ops; 378 } 379 380 struct Qdisc_class_common { 381 u32 classid; 382 struct hlist_node hnode; 383 }; 384 385 struct Qdisc_class_hash { 386 struct hlist_head *hash; 387 unsigned int hashsize; 388 unsigned int hashmask; 389 unsigned int hashelems; 390 }; 391 392 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 393 { 394 id ^= id >> 8; 395 id ^= id >> 4; 396 return id & mask; 397 } 398 399 static inline struct Qdisc_class_common * 400 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 401 { 402 struct Qdisc_class_common *cl; 403 unsigned int h; 404 405 if (!id) 406 return NULL; 407 408 h = qdisc_class_hash(id, hash->hashmask); 409 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 410 if (cl->classid == id) 411 return cl; 412 } 413 return NULL; 414 } 415 416 int qdisc_class_hash_init(struct Qdisc_class_hash *); 417 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 418 struct Qdisc_class_common *); 419 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 420 struct Qdisc_class_common *); 421 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 422 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 423 424 void dev_init_scheduler(struct net_device *dev); 425 void dev_shutdown(struct net_device *dev); 426 void dev_activate(struct net_device *dev); 427 void dev_deactivate(struct net_device *dev); 428 void dev_deactivate_many(struct list_head *head); 429 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 430 struct Qdisc *qdisc); 431 void qdisc_reset(struct Qdisc *qdisc); 432 void qdisc_destroy(struct Qdisc *qdisc); 433 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 434 unsigned int len); 435 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 436 const struct Qdisc_ops *ops); 437 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 438 const struct Qdisc_ops *ops, u32 parentid); 439 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 440 const struct qdisc_size_table *stab); 441 int skb_do_redirect(struct sk_buff *); 442 443 static inline void skb_reset_tc(struct sk_buff *skb) 444 { 445 #ifdef CONFIG_NET_CLS_ACT 446 skb->tc_redirected = 0; 447 #endif 448 } 449 450 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 451 { 452 #ifdef CONFIG_NET_CLS_ACT 453 return skb->tc_at_ingress; 454 #else 455 return false; 456 #endif 457 } 458 459 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 460 { 461 #ifdef CONFIG_NET_CLS_ACT 462 if (skb->tc_skip_classify) { 463 skb->tc_skip_classify = 0; 464 return true; 465 } 466 #endif 467 return false; 468 } 469 470 /* Reset all TX qdiscs greater then index of a device. */ 471 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 472 { 473 struct Qdisc *qdisc; 474 475 for (; i < dev->num_tx_queues; i++) { 476 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 477 if (qdisc) { 478 spin_lock_bh(qdisc_lock(qdisc)); 479 qdisc_reset(qdisc); 480 spin_unlock_bh(qdisc_lock(qdisc)); 481 } 482 } 483 } 484 485 static inline void qdisc_reset_all_tx(struct net_device *dev) 486 { 487 qdisc_reset_all_tx_gt(dev, 0); 488 } 489 490 /* Are all TX queues of the device empty? */ 491 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 492 { 493 unsigned int i; 494 495 rcu_read_lock(); 496 for (i = 0; i < dev->num_tx_queues; i++) { 497 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 498 const struct Qdisc *q = rcu_dereference(txq->qdisc); 499 500 if (q->q.qlen) { 501 rcu_read_unlock(); 502 return false; 503 } 504 } 505 rcu_read_unlock(); 506 return true; 507 } 508 509 /* Are any of the TX qdiscs changing? */ 510 static inline bool qdisc_tx_changing(const struct net_device *dev) 511 { 512 unsigned int i; 513 514 for (i = 0; i < dev->num_tx_queues; i++) { 515 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 516 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 517 return true; 518 } 519 return false; 520 } 521 522 /* Is the device using the noop qdisc on all queues? */ 523 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 524 { 525 unsigned int i; 526 527 for (i = 0; i < dev->num_tx_queues; i++) { 528 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 529 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 530 return false; 531 } 532 return true; 533 } 534 535 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 536 { 537 return qdisc_skb_cb(skb)->pkt_len; 538 } 539 540 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 541 enum net_xmit_qdisc_t { 542 __NET_XMIT_STOLEN = 0x00010000, 543 __NET_XMIT_BYPASS = 0x00020000, 544 }; 545 546 #ifdef CONFIG_NET_CLS_ACT 547 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 548 #else 549 #define net_xmit_drop_count(e) (1) 550 #endif 551 552 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 553 const struct Qdisc *sch) 554 { 555 #ifdef CONFIG_NET_SCHED 556 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 557 558 if (stab) 559 __qdisc_calculate_pkt_len(skb, stab); 560 #endif 561 } 562 563 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 564 struct sk_buff **to_free) 565 { 566 qdisc_calculate_pkt_len(skb, sch); 567 return sch->enqueue(skb, sch, to_free); 568 } 569 570 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 571 { 572 return q->flags & TCQ_F_CPUSTATS; 573 } 574 575 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 576 __u64 bytes, __u32 packets) 577 { 578 bstats->bytes += bytes; 579 bstats->packets += packets; 580 } 581 582 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 583 const struct sk_buff *skb) 584 { 585 _bstats_update(bstats, 586 qdisc_pkt_len(skb), 587 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 588 } 589 590 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 591 __u64 bytes, __u32 packets) 592 { 593 u64_stats_update_begin(&bstats->syncp); 594 _bstats_update(&bstats->bstats, bytes, packets); 595 u64_stats_update_end(&bstats->syncp); 596 } 597 598 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 599 const struct sk_buff *skb) 600 { 601 u64_stats_update_begin(&bstats->syncp); 602 bstats_update(&bstats->bstats, skb); 603 u64_stats_update_end(&bstats->syncp); 604 } 605 606 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 607 const struct sk_buff *skb) 608 { 609 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 610 } 611 612 static inline void qdisc_bstats_update(struct Qdisc *sch, 613 const struct sk_buff *skb) 614 { 615 bstats_update(&sch->bstats, skb); 616 } 617 618 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 619 const struct sk_buff *skb) 620 { 621 sch->qstats.backlog -= qdisc_pkt_len(skb); 622 } 623 624 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 625 const struct sk_buff *skb) 626 { 627 sch->qstats.backlog += qdisc_pkt_len(skb); 628 } 629 630 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 631 { 632 sch->qstats.drops += count; 633 } 634 635 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 636 { 637 qstats->drops++; 638 } 639 640 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 641 { 642 qstats->overlimits++; 643 } 644 645 static inline void qdisc_qstats_drop(struct Qdisc *sch) 646 { 647 qstats_drop_inc(&sch->qstats); 648 } 649 650 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 651 { 652 this_cpu_inc(sch->cpu_qstats->drops); 653 } 654 655 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 656 { 657 sch->qstats.overlimits++; 658 } 659 660 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 661 { 662 qh->head = NULL; 663 qh->tail = NULL; 664 qh->qlen = 0; 665 } 666 667 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 668 struct qdisc_skb_head *qh) 669 { 670 struct sk_buff *last = qh->tail; 671 672 if (last) { 673 skb->next = NULL; 674 last->next = skb; 675 qh->tail = skb; 676 } else { 677 qh->tail = skb; 678 qh->head = skb; 679 } 680 qh->qlen++; 681 qdisc_qstats_backlog_inc(sch, skb); 682 683 return NET_XMIT_SUCCESS; 684 } 685 686 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 687 { 688 return __qdisc_enqueue_tail(skb, sch, &sch->q); 689 } 690 691 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 692 { 693 struct sk_buff *skb = qh->head; 694 695 if (likely(skb != NULL)) { 696 qh->head = skb->next; 697 qh->qlen--; 698 if (qh->head == NULL) 699 qh->tail = NULL; 700 skb->next = NULL; 701 } 702 703 return skb; 704 } 705 706 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 707 { 708 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 709 710 if (likely(skb != NULL)) { 711 qdisc_qstats_backlog_dec(sch, skb); 712 qdisc_bstats_update(sch, skb); 713 } 714 715 return skb; 716 } 717 718 /* Instead of calling kfree_skb() while root qdisc lock is held, 719 * queue the skb for future freeing at end of __dev_xmit_skb() 720 */ 721 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 722 { 723 skb->next = *to_free; 724 *to_free = skb; 725 } 726 727 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 728 struct qdisc_skb_head *qh, 729 struct sk_buff **to_free) 730 { 731 struct sk_buff *skb = __qdisc_dequeue_head(qh); 732 733 if (likely(skb != NULL)) { 734 unsigned int len = qdisc_pkt_len(skb); 735 736 qdisc_qstats_backlog_dec(sch, skb); 737 __qdisc_drop(skb, to_free); 738 return len; 739 } 740 741 return 0; 742 } 743 744 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 745 struct sk_buff **to_free) 746 { 747 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 748 } 749 750 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 751 { 752 const struct qdisc_skb_head *qh = &sch->q; 753 754 return qh->head; 755 } 756 757 /* generic pseudo peek method for non-work-conserving qdisc */ 758 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 759 { 760 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 761 if (!sch->gso_skb) { 762 sch->gso_skb = sch->dequeue(sch); 763 if (sch->gso_skb) { 764 /* it's still part of the queue */ 765 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 766 sch->q.qlen++; 767 } 768 } 769 770 return sch->gso_skb; 771 } 772 773 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 774 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 775 { 776 struct sk_buff *skb = sch->gso_skb; 777 778 if (skb) { 779 sch->gso_skb = NULL; 780 qdisc_qstats_backlog_dec(sch, skb); 781 sch->q.qlen--; 782 } else { 783 skb = sch->dequeue(sch); 784 } 785 786 return skb; 787 } 788 789 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 790 { 791 /* 792 * We do not know the backlog in bytes of this list, it 793 * is up to the caller to correct it 794 */ 795 ASSERT_RTNL(); 796 if (qh->qlen) { 797 rtnl_kfree_skbs(qh->head, qh->tail); 798 799 qh->head = NULL; 800 qh->tail = NULL; 801 qh->qlen = 0; 802 } 803 } 804 805 static inline void qdisc_reset_queue(struct Qdisc *sch) 806 { 807 __qdisc_reset_queue(&sch->q); 808 sch->qstats.backlog = 0; 809 } 810 811 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 812 struct Qdisc **pold) 813 { 814 struct Qdisc *old; 815 816 sch_tree_lock(sch); 817 old = *pold; 818 *pold = new; 819 if (old != NULL) { 820 unsigned int qlen = old->q.qlen; 821 unsigned int backlog = old->qstats.backlog; 822 823 qdisc_reset(old); 824 qdisc_tree_reduce_backlog(old, qlen, backlog); 825 } 826 sch_tree_unlock(sch); 827 828 return old; 829 } 830 831 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 832 { 833 rtnl_kfree_skbs(skb, skb); 834 qdisc_qstats_drop(sch); 835 } 836 837 838 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 839 struct sk_buff **to_free) 840 { 841 __qdisc_drop(skb, to_free); 842 qdisc_qstats_drop(sch); 843 844 return NET_XMIT_DROP; 845 } 846 847 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 848 long it will take to send a packet given its size. 849 */ 850 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 851 { 852 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 853 if (slot < 0) 854 slot = 0; 855 slot >>= rtab->rate.cell_log; 856 if (slot > 255) 857 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 858 return rtab->data[slot]; 859 } 860 861 struct psched_ratecfg { 862 u64 rate_bytes_ps; /* bytes per second */ 863 u32 mult; 864 u16 overhead; 865 u8 linklayer; 866 u8 shift; 867 }; 868 869 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 870 unsigned int len) 871 { 872 len += r->overhead; 873 874 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 875 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 876 877 return ((u64)len * r->mult) >> r->shift; 878 } 879 880 void psched_ratecfg_precompute(struct psched_ratecfg *r, 881 const struct tc_ratespec *conf, 882 u64 rate64); 883 884 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 885 const struct psched_ratecfg *r) 886 { 887 memset(res, 0, sizeof(*res)); 888 889 /* legacy struct tc_ratespec has a 32bit @rate field 890 * Qdisc using 64bit rate should add new attributes 891 * in order to maintain compatibility. 892 */ 893 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 894 895 res->overhead = r->overhead; 896 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 897 } 898 899 #endif 900