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 <linux/workqueue.h> 14 #include <net/gen_stats.h> 15 #include <net/rtnetlink.h> 16 17 struct Qdisc_ops; 18 struct qdisc_walker; 19 struct tcf_walker; 20 struct module; 21 22 struct qdisc_rate_table { 23 struct tc_ratespec rate; 24 u32 data[256]; 25 struct qdisc_rate_table *next; 26 int refcnt; 27 }; 28 29 enum qdisc_state_t { 30 __QDISC_STATE_SCHED, 31 __QDISC_STATE_DEACTIVATED, 32 }; 33 34 struct qdisc_size_table { 35 struct rcu_head rcu; 36 struct list_head list; 37 struct tc_sizespec szopts; 38 int refcnt; 39 u16 data[]; 40 }; 41 42 /* similar to sk_buff_head, but skb->prev pointer is undefined. */ 43 struct qdisc_skb_head { 44 struct sk_buff *head; 45 struct sk_buff *tail; 46 __u32 qlen; 47 spinlock_t lock; 48 }; 49 50 struct Qdisc { 51 int (*enqueue)(struct sk_buff *skb, 52 struct Qdisc *sch, 53 struct sk_buff **to_free); 54 struct sk_buff * (*dequeue)(struct Qdisc *sch); 55 unsigned int flags; 56 #define TCQ_F_BUILTIN 1 57 #define TCQ_F_INGRESS 2 58 #define TCQ_F_CAN_BYPASS 4 59 #define TCQ_F_MQROOT 8 60 #define TCQ_F_ONETXQUEUE 0x10 /* dequeue_skb() can assume all skbs are for 61 * q->dev_queue : It can test 62 * netif_xmit_frozen_or_stopped() before 63 * dequeueing next packet. 64 * Its true for MQ/MQPRIO slaves, or non 65 * multiqueue device. 66 */ 67 #define TCQ_F_WARN_NONWC (1 << 16) 68 #define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */ 69 #define TCQ_F_NOPARENT 0x40 /* root of its hierarchy : 70 * qdisc_tree_decrease_qlen() should stop. 71 */ 72 #define TCQ_F_INVISIBLE 0x80 /* invisible by default in dump */ 73 u32 limit; 74 const struct Qdisc_ops *ops; 75 struct qdisc_size_table __rcu *stab; 76 struct hlist_node hash; 77 u32 handle; 78 u32 parent; 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 int padded; 98 refcount_t refcnt; 99 100 spinlock_t busylock ____cacheline_aligned_in_smp; 101 }; 102 103 static inline void qdisc_refcount_inc(struct Qdisc *qdisc) 104 { 105 if (qdisc->flags & TCQ_F_BUILTIN) 106 return; 107 refcount_inc(&qdisc->refcnt); 108 } 109 110 static inline bool qdisc_is_running(const struct Qdisc *qdisc) 111 { 112 return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; 113 } 114 115 static inline bool qdisc_run_begin(struct Qdisc *qdisc) 116 { 117 if (qdisc_is_running(qdisc)) 118 return false; 119 /* Variant of write_seqcount_begin() telling lockdep a trylock 120 * was attempted. 121 */ 122 raw_write_seqcount_begin(&qdisc->running); 123 seqcount_acquire(&qdisc->running.dep_map, 0, 1, _RET_IP_); 124 return true; 125 } 126 127 static inline void qdisc_run_end(struct Qdisc *qdisc) 128 { 129 write_seqcount_end(&qdisc->running); 130 } 131 132 static inline bool qdisc_may_bulk(const struct Qdisc *qdisc) 133 { 134 return qdisc->flags & TCQ_F_ONETXQUEUE; 135 } 136 137 static inline int qdisc_avail_bulklimit(const struct netdev_queue *txq) 138 { 139 #ifdef CONFIG_BQL 140 /* Non-BQL migrated drivers will return 0, too. */ 141 return dql_avail(&txq->dql); 142 #else 143 return 0; 144 #endif 145 } 146 147 struct Qdisc_class_ops { 148 /* Child qdisc manipulation */ 149 struct netdev_queue * (*select_queue)(struct Qdisc *, struct tcmsg *); 150 int (*graft)(struct Qdisc *, unsigned long cl, 151 struct Qdisc *, struct Qdisc **); 152 struct Qdisc * (*leaf)(struct Qdisc *, unsigned long cl); 153 void (*qlen_notify)(struct Qdisc *, unsigned long); 154 155 /* Class manipulation routines */ 156 unsigned long (*find)(struct Qdisc *, u32 classid); 157 int (*change)(struct Qdisc *, u32, u32, 158 struct nlattr **, unsigned long *); 159 int (*delete)(struct Qdisc *, unsigned long); 160 void (*walk)(struct Qdisc *, struct qdisc_walker * arg); 161 162 /* Filter manipulation */ 163 struct tcf_block * (*tcf_block)(struct Qdisc *, unsigned long); 164 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 165 u32 classid); 166 void (*unbind_tcf)(struct Qdisc *, unsigned long); 167 168 /* rtnetlink specific */ 169 int (*dump)(struct Qdisc *, unsigned long, 170 struct sk_buff *skb, struct tcmsg*); 171 int (*dump_stats)(struct Qdisc *, unsigned long, 172 struct gnet_dump *); 173 }; 174 175 struct Qdisc_ops { 176 struct Qdisc_ops *next; 177 const struct Qdisc_class_ops *cl_ops; 178 char id[IFNAMSIZ]; 179 int priv_size; 180 181 int (*enqueue)(struct sk_buff *skb, 182 struct Qdisc *sch, 183 struct sk_buff **to_free); 184 struct sk_buff * (*dequeue)(struct Qdisc *); 185 struct sk_buff * (*peek)(struct Qdisc *); 186 187 int (*init)(struct Qdisc *, struct nlattr *arg); 188 void (*reset)(struct Qdisc *); 189 void (*destroy)(struct Qdisc *); 190 int (*change)(struct Qdisc *, struct nlattr *arg); 191 void (*attach)(struct Qdisc *); 192 193 int (*dump)(struct Qdisc *, struct sk_buff *); 194 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 195 196 struct module *owner; 197 }; 198 199 200 struct tcf_result { 201 union { 202 struct { 203 unsigned long class; 204 u32 classid; 205 }; 206 const struct tcf_proto *goto_tp; 207 }; 208 }; 209 210 struct tcf_proto_ops { 211 struct list_head head; 212 char kind[IFNAMSIZ]; 213 214 int (*classify)(struct sk_buff *, 215 const struct tcf_proto *, 216 struct tcf_result *); 217 int (*init)(struct tcf_proto*); 218 void (*destroy)(struct tcf_proto*); 219 220 void* (*get)(struct tcf_proto*, u32 handle); 221 int (*change)(struct net *net, struct sk_buff *, 222 struct tcf_proto*, unsigned long, 223 u32 handle, struct nlattr **, 224 void **, bool); 225 int (*delete)(struct tcf_proto*, void *, bool*); 226 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 227 void (*bind_class)(void *, u32, unsigned long); 228 229 /* rtnetlink specific */ 230 int (*dump)(struct net*, struct tcf_proto*, void *, 231 struct sk_buff *skb, struct tcmsg*); 232 233 struct module *owner; 234 }; 235 236 struct tcf_proto { 237 /* Fast access part */ 238 struct tcf_proto __rcu *next; 239 void __rcu *root; 240 int (*classify)(struct sk_buff *, 241 const struct tcf_proto *, 242 struct tcf_result *); 243 __be16 protocol; 244 245 /* All the rest */ 246 u32 prio; 247 u32 classid; 248 struct Qdisc *q; 249 void *data; 250 const struct tcf_proto_ops *ops; 251 struct tcf_chain *chain; 252 struct rcu_head rcu; 253 }; 254 255 struct qdisc_skb_cb { 256 unsigned int pkt_len; 257 u16 slave_dev_queue_mapping; 258 u16 tc_classid; 259 #define QDISC_CB_PRIV_LEN 20 260 unsigned char data[QDISC_CB_PRIV_LEN]; 261 }; 262 263 struct tcf_chain { 264 struct tcf_proto __rcu *filter_chain; 265 struct tcf_proto __rcu **p_filter_chain; 266 struct list_head list; 267 struct tcf_block *block; 268 u32 index; /* chain index */ 269 unsigned int refcnt; 270 }; 271 272 struct tcf_block { 273 struct list_head chain_list; 274 struct net *net; 275 struct Qdisc *q; 276 struct list_head cb_list; 277 struct work_struct work; 278 }; 279 280 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 281 { 282 struct qdisc_skb_cb *qcb; 283 284 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 285 BUILD_BUG_ON(sizeof(qcb->data) < sz); 286 } 287 288 static inline int qdisc_qlen(const struct Qdisc *q) 289 { 290 return q->q.qlen; 291 } 292 293 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 294 { 295 return (struct qdisc_skb_cb *)skb->cb; 296 } 297 298 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 299 { 300 return &qdisc->q.lock; 301 } 302 303 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 304 { 305 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 306 307 return q; 308 } 309 310 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 311 { 312 return qdisc->dev_queue->qdisc_sleeping; 313 } 314 315 /* The qdisc root lock is a mechanism by which to top level 316 * of a qdisc tree can be locked from any qdisc node in the 317 * forest. This allows changing the configuration of some 318 * aspect of the qdisc tree while blocking out asynchronous 319 * qdisc access in the packet processing paths. 320 * 321 * It is only legal to do this when the root will not change 322 * on us. Otherwise we'll potentially lock the wrong qdisc 323 * root. This is enforced by holding the RTNL semaphore, which 324 * all users of this lock accessor must do. 325 */ 326 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 327 { 328 struct Qdisc *root = qdisc_root(qdisc); 329 330 ASSERT_RTNL(); 331 return qdisc_lock(root); 332 } 333 334 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 335 { 336 struct Qdisc *root = qdisc_root_sleeping(qdisc); 337 338 ASSERT_RTNL(); 339 return qdisc_lock(root); 340 } 341 342 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 343 { 344 struct Qdisc *root = qdisc_root_sleeping(qdisc); 345 346 ASSERT_RTNL(); 347 return &root->running; 348 } 349 350 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 351 { 352 return qdisc->dev_queue->dev; 353 } 354 355 static inline void sch_tree_lock(const struct Qdisc *q) 356 { 357 spin_lock_bh(qdisc_root_sleeping_lock(q)); 358 } 359 360 static inline void sch_tree_unlock(const struct Qdisc *q) 361 { 362 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 363 } 364 365 extern struct Qdisc noop_qdisc; 366 extern struct Qdisc_ops noop_qdisc_ops; 367 extern struct Qdisc_ops pfifo_fast_ops; 368 extern struct Qdisc_ops mq_qdisc_ops; 369 extern struct Qdisc_ops noqueue_qdisc_ops; 370 extern const struct Qdisc_ops *default_qdisc_ops; 371 static inline const struct Qdisc_ops * 372 get_default_qdisc_ops(const struct net_device *dev, int ntx) 373 { 374 return ntx < dev->real_num_tx_queues ? 375 default_qdisc_ops : &pfifo_fast_ops; 376 } 377 378 struct Qdisc_class_common { 379 u32 classid; 380 struct hlist_node hnode; 381 }; 382 383 struct Qdisc_class_hash { 384 struct hlist_head *hash; 385 unsigned int hashsize; 386 unsigned int hashmask; 387 unsigned int hashelems; 388 }; 389 390 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 391 { 392 id ^= id >> 8; 393 id ^= id >> 4; 394 return id & mask; 395 } 396 397 static inline struct Qdisc_class_common * 398 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 399 { 400 struct Qdisc_class_common *cl; 401 unsigned int h; 402 403 if (!id) 404 return NULL; 405 406 h = qdisc_class_hash(id, hash->hashmask); 407 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 408 if (cl->classid == id) 409 return cl; 410 } 411 return NULL; 412 } 413 414 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid) 415 { 416 u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY; 417 418 return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL; 419 } 420 421 int qdisc_class_hash_init(struct Qdisc_class_hash *); 422 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 423 struct Qdisc_class_common *); 424 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 425 struct Qdisc_class_common *); 426 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 427 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 428 429 void dev_init_scheduler(struct net_device *dev); 430 void dev_shutdown(struct net_device *dev); 431 void dev_activate(struct net_device *dev); 432 void dev_deactivate(struct net_device *dev); 433 void dev_deactivate_many(struct list_head *head); 434 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 435 struct Qdisc *qdisc); 436 void qdisc_reset(struct Qdisc *qdisc); 437 void qdisc_destroy(struct Qdisc *qdisc); 438 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 439 unsigned int len); 440 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 441 const struct Qdisc_ops *ops); 442 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 443 const struct Qdisc_ops *ops, u32 parentid); 444 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 445 const struct qdisc_size_table *stab); 446 int skb_do_redirect(struct sk_buff *); 447 448 static inline void skb_reset_tc(struct sk_buff *skb) 449 { 450 #ifdef CONFIG_NET_CLS_ACT 451 skb->tc_redirected = 0; 452 #endif 453 } 454 455 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 456 { 457 #ifdef CONFIG_NET_CLS_ACT 458 return skb->tc_at_ingress; 459 #else 460 return false; 461 #endif 462 } 463 464 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 465 { 466 #ifdef CONFIG_NET_CLS_ACT 467 if (skb->tc_skip_classify) { 468 skb->tc_skip_classify = 0; 469 return true; 470 } 471 #endif 472 return false; 473 } 474 475 /* Reset all TX qdiscs greater then index of a device. */ 476 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 477 { 478 struct Qdisc *qdisc; 479 480 for (; i < dev->num_tx_queues; i++) { 481 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 482 if (qdisc) { 483 spin_lock_bh(qdisc_lock(qdisc)); 484 qdisc_reset(qdisc); 485 spin_unlock_bh(qdisc_lock(qdisc)); 486 } 487 } 488 } 489 490 static inline void qdisc_reset_all_tx(struct net_device *dev) 491 { 492 qdisc_reset_all_tx_gt(dev, 0); 493 } 494 495 /* Are all TX queues of the device empty? */ 496 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 497 { 498 unsigned int i; 499 500 rcu_read_lock(); 501 for (i = 0; i < dev->num_tx_queues; i++) { 502 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 503 const struct Qdisc *q = rcu_dereference(txq->qdisc); 504 505 if (q->q.qlen) { 506 rcu_read_unlock(); 507 return false; 508 } 509 } 510 rcu_read_unlock(); 511 return true; 512 } 513 514 /* Are any of the TX qdiscs changing? */ 515 static inline bool qdisc_tx_changing(const struct net_device *dev) 516 { 517 unsigned int i; 518 519 for (i = 0; i < dev->num_tx_queues; i++) { 520 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 521 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 522 return true; 523 } 524 return false; 525 } 526 527 /* Is the device using the noop qdisc on all queues? */ 528 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 529 { 530 unsigned int i; 531 532 for (i = 0; i < dev->num_tx_queues; i++) { 533 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 534 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 535 return false; 536 } 537 return true; 538 } 539 540 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 541 { 542 return qdisc_skb_cb(skb)->pkt_len; 543 } 544 545 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 546 enum net_xmit_qdisc_t { 547 __NET_XMIT_STOLEN = 0x00010000, 548 __NET_XMIT_BYPASS = 0x00020000, 549 }; 550 551 #ifdef CONFIG_NET_CLS_ACT 552 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 553 #else 554 #define net_xmit_drop_count(e) (1) 555 #endif 556 557 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 558 const struct Qdisc *sch) 559 { 560 #ifdef CONFIG_NET_SCHED 561 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 562 563 if (stab) 564 __qdisc_calculate_pkt_len(skb, stab); 565 #endif 566 } 567 568 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 569 struct sk_buff **to_free) 570 { 571 qdisc_calculate_pkt_len(skb, sch); 572 return sch->enqueue(skb, sch, to_free); 573 } 574 575 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 576 { 577 return q->flags & TCQ_F_CPUSTATS; 578 } 579 580 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 581 __u64 bytes, __u32 packets) 582 { 583 bstats->bytes += bytes; 584 bstats->packets += packets; 585 } 586 587 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 588 const struct sk_buff *skb) 589 { 590 _bstats_update(bstats, 591 qdisc_pkt_len(skb), 592 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 593 } 594 595 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 596 __u64 bytes, __u32 packets) 597 { 598 u64_stats_update_begin(&bstats->syncp); 599 _bstats_update(&bstats->bstats, bytes, packets); 600 u64_stats_update_end(&bstats->syncp); 601 } 602 603 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 604 const struct sk_buff *skb) 605 { 606 u64_stats_update_begin(&bstats->syncp); 607 bstats_update(&bstats->bstats, skb); 608 u64_stats_update_end(&bstats->syncp); 609 } 610 611 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 612 const struct sk_buff *skb) 613 { 614 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 615 } 616 617 static inline void qdisc_bstats_update(struct Qdisc *sch, 618 const struct sk_buff *skb) 619 { 620 bstats_update(&sch->bstats, skb); 621 } 622 623 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 624 const struct sk_buff *skb) 625 { 626 sch->qstats.backlog -= qdisc_pkt_len(skb); 627 } 628 629 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 630 const struct sk_buff *skb) 631 { 632 sch->qstats.backlog += qdisc_pkt_len(skb); 633 } 634 635 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 636 { 637 sch->qstats.drops += count; 638 } 639 640 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 641 { 642 qstats->drops++; 643 } 644 645 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 646 { 647 qstats->overlimits++; 648 } 649 650 static inline void qdisc_qstats_drop(struct Qdisc *sch) 651 { 652 qstats_drop_inc(&sch->qstats); 653 } 654 655 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 656 { 657 this_cpu_inc(sch->cpu_qstats->drops); 658 } 659 660 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 661 { 662 sch->qstats.overlimits++; 663 } 664 665 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 666 { 667 qh->head = NULL; 668 qh->tail = NULL; 669 qh->qlen = 0; 670 } 671 672 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 673 struct qdisc_skb_head *qh) 674 { 675 struct sk_buff *last = qh->tail; 676 677 if (last) { 678 skb->next = NULL; 679 last->next = skb; 680 qh->tail = skb; 681 } else { 682 qh->tail = skb; 683 qh->head = skb; 684 } 685 qh->qlen++; 686 qdisc_qstats_backlog_inc(sch, skb); 687 688 return NET_XMIT_SUCCESS; 689 } 690 691 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 692 { 693 return __qdisc_enqueue_tail(skb, sch, &sch->q); 694 } 695 696 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 697 { 698 struct sk_buff *skb = qh->head; 699 700 if (likely(skb != NULL)) { 701 qh->head = skb->next; 702 qh->qlen--; 703 if (qh->head == NULL) 704 qh->tail = NULL; 705 skb->next = NULL; 706 } 707 708 return skb; 709 } 710 711 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 712 { 713 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 714 715 if (likely(skb != NULL)) { 716 qdisc_qstats_backlog_dec(sch, skb); 717 qdisc_bstats_update(sch, skb); 718 } 719 720 return skb; 721 } 722 723 /* Instead of calling kfree_skb() while root qdisc lock is held, 724 * queue the skb for future freeing at end of __dev_xmit_skb() 725 */ 726 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 727 { 728 skb->next = *to_free; 729 *to_free = skb; 730 } 731 732 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 733 struct qdisc_skb_head *qh, 734 struct sk_buff **to_free) 735 { 736 struct sk_buff *skb = __qdisc_dequeue_head(qh); 737 738 if (likely(skb != NULL)) { 739 unsigned int len = qdisc_pkt_len(skb); 740 741 qdisc_qstats_backlog_dec(sch, skb); 742 __qdisc_drop(skb, to_free); 743 return len; 744 } 745 746 return 0; 747 } 748 749 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 750 struct sk_buff **to_free) 751 { 752 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 753 } 754 755 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 756 { 757 const struct qdisc_skb_head *qh = &sch->q; 758 759 return qh->head; 760 } 761 762 /* generic pseudo peek method for non-work-conserving qdisc */ 763 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 764 { 765 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 766 if (!sch->gso_skb) { 767 sch->gso_skb = sch->dequeue(sch); 768 if (sch->gso_skb) { 769 /* it's still part of the queue */ 770 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 771 sch->q.qlen++; 772 } 773 } 774 775 return sch->gso_skb; 776 } 777 778 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 779 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 780 { 781 struct sk_buff *skb = sch->gso_skb; 782 783 if (skb) { 784 sch->gso_skb = NULL; 785 qdisc_qstats_backlog_dec(sch, skb); 786 sch->q.qlen--; 787 } else { 788 skb = sch->dequeue(sch); 789 } 790 791 return skb; 792 } 793 794 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 795 { 796 /* 797 * We do not know the backlog in bytes of this list, it 798 * is up to the caller to correct it 799 */ 800 ASSERT_RTNL(); 801 if (qh->qlen) { 802 rtnl_kfree_skbs(qh->head, qh->tail); 803 804 qh->head = NULL; 805 qh->tail = NULL; 806 qh->qlen = 0; 807 } 808 } 809 810 static inline void qdisc_reset_queue(struct Qdisc *sch) 811 { 812 __qdisc_reset_queue(&sch->q); 813 sch->qstats.backlog = 0; 814 } 815 816 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 817 struct Qdisc **pold) 818 { 819 struct Qdisc *old; 820 821 sch_tree_lock(sch); 822 old = *pold; 823 *pold = new; 824 if (old != NULL) { 825 unsigned int qlen = old->q.qlen; 826 unsigned int backlog = old->qstats.backlog; 827 828 qdisc_reset(old); 829 qdisc_tree_reduce_backlog(old, qlen, backlog); 830 } 831 sch_tree_unlock(sch); 832 833 return old; 834 } 835 836 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 837 { 838 rtnl_kfree_skbs(skb, skb); 839 qdisc_qstats_drop(sch); 840 } 841 842 843 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 844 struct sk_buff **to_free) 845 { 846 __qdisc_drop(skb, to_free); 847 qdisc_qstats_drop(sch); 848 849 return NET_XMIT_DROP; 850 } 851 852 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 853 long it will take to send a packet given its size. 854 */ 855 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 856 { 857 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 858 if (slot < 0) 859 slot = 0; 860 slot >>= rtab->rate.cell_log; 861 if (slot > 255) 862 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 863 return rtab->data[slot]; 864 } 865 866 struct psched_ratecfg { 867 u64 rate_bytes_ps; /* bytes per second */ 868 u32 mult; 869 u16 overhead; 870 u8 linklayer; 871 u8 shift; 872 }; 873 874 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 875 unsigned int len) 876 { 877 len += r->overhead; 878 879 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 880 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 881 882 return ((u64)len * r->mult) >> r->shift; 883 } 884 885 void psched_ratecfg_precompute(struct psched_ratecfg *r, 886 const struct tc_ratespec *conf, 887 u64 rate64); 888 889 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 890 const struct psched_ratecfg *r) 891 { 892 memset(res, 0, sizeof(*res)); 893 894 /* legacy struct tc_ratespec has a 32bit @rate field 895 * Qdisc using 64bit rate should add new attributes 896 * in order to maintain compatibility. 897 */ 898 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 899 900 res->overhead = r->overhead; 901 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 902 } 903 904 #endif 905