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