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 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 (*find)(struct Qdisc *, u32 classid); 158 int (*change)(struct Qdisc *, u32, u32, 159 struct nlattr **, unsigned long *); 160 int (*delete)(struct Qdisc *, unsigned long); 161 void (*walk)(struct Qdisc *, struct qdisc_walker * arg); 162 163 /* Filter manipulation */ 164 struct tcf_block * (*tcf_block)(struct Qdisc *sch, 165 unsigned long arg); 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 *sch, struct nlattr *arg); 190 void (*reset)(struct Qdisc *); 191 void (*destroy)(struct Qdisc *); 192 int (*change)(struct Qdisc *sch, 193 struct nlattr *arg); 194 void (*attach)(struct Qdisc *sch); 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 void* (*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 void **, bool); 228 int (*delete)(struct tcf_proto*, void *, bool*); 229 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 230 void (*bind_class)(void *, u32, unsigned long); 231 232 /* rtnetlink specific */ 233 int (*dump)(struct net*, struct tcf_proto*, void *, 234 struct sk_buff *skb, struct tcmsg*); 235 236 struct module *owner; 237 }; 238 239 struct tcf_proto { 240 /* Fast access part */ 241 struct tcf_proto __rcu *next; 242 void __rcu *root; 243 int (*classify)(struct sk_buff *, 244 const struct tcf_proto *, 245 struct tcf_result *); 246 __be16 protocol; 247 248 /* All the rest */ 249 u32 prio; 250 u32 classid; 251 struct Qdisc *q; 252 void *data; 253 const struct tcf_proto_ops *ops; 254 struct tcf_chain *chain; 255 struct rcu_head rcu; 256 }; 257 258 struct qdisc_skb_cb { 259 unsigned int pkt_len; 260 u16 slave_dev_queue_mapping; 261 u16 tc_classid; 262 #define QDISC_CB_PRIV_LEN 20 263 unsigned char data[QDISC_CB_PRIV_LEN]; 264 }; 265 266 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv); 267 268 struct tcf_chain { 269 struct tcf_proto __rcu *filter_chain; 270 tcf_chain_head_change_t *chain_head_change; 271 void *chain_head_change_priv; 272 struct list_head list; 273 struct tcf_block *block; 274 u32 index; /* chain index */ 275 unsigned int refcnt; 276 }; 277 278 struct tcf_block { 279 struct list_head chain_list; 280 struct net *net; 281 struct Qdisc *q; 282 struct list_head cb_list; 283 }; 284 285 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 286 { 287 struct qdisc_skb_cb *qcb; 288 289 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 290 BUILD_BUG_ON(sizeof(qcb->data) < sz); 291 } 292 293 static inline int qdisc_qlen(const struct Qdisc *q) 294 { 295 return q->q.qlen; 296 } 297 298 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 299 { 300 return (struct qdisc_skb_cb *)skb->cb; 301 } 302 303 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 304 { 305 return &qdisc->q.lock; 306 } 307 308 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 309 { 310 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 311 312 return q; 313 } 314 315 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 316 { 317 return qdisc->dev_queue->qdisc_sleeping; 318 } 319 320 /* The qdisc root lock is a mechanism by which to top level 321 * of a qdisc tree can be locked from any qdisc node in the 322 * forest. This allows changing the configuration of some 323 * aspect of the qdisc tree while blocking out asynchronous 324 * qdisc access in the packet processing paths. 325 * 326 * It is only legal to do this when the root will not change 327 * on us. Otherwise we'll potentially lock the wrong qdisc 328 * root. This is enforced by holding the RTNL semaphore, which 329 * all users of this lock accessor must do. 330 */ 331 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 332 { 333 struct Qdisc *root = qdisc_root(qdisc); 334 335 ASSERT_RTNL(); 336 return qdisc_lock(root); 337 } 338 339 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 340 { 341 struct Qdisc *root = qdisc_root_sleeping(qdisc); 342 343 ASSERT_RTNL(); 344 return qdisc_lock(root); 345 } 346 347 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 348 { 349 struct Qdisc *root = qdisc_root_sleeping(qdisc); 350 351 ASSERT_RTNL(); 352 return &root->running; 353 } 354 355 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 356 { 357 return qdisc->dev_queue->dev; 358 } 359 360 static inline void sch_tree_lock(const struct Qdisc *q) 361 { 362 spin_lock_bh(qdisc_root_sleeping_lock(q)); 363 } 364 365 static inline void sch_tree_unlock(const struct Qdisc *q) 366 { 367 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 368 } 369 370 extern struct Qdisc noop_qdisc; 371 extern struct Qdisc_ops noop_qdisc_ops; 372 extern struct Qdisc_ops pfifo_fast_ops; 373 extern struct Qdisc_ops mq_qdisc_ops; 374 extern struct Qdisc_ops noqueue_qdisc_ops; 375 extern const struct Qdisc_ops *default_qdisc_ops; 376 static inline const struct Qdisc_ops * 377 get_default_qdisc_ops(const struct net_device *dev, int ntx) 378 { 379 return ntx < dev->real_num_tx_queues ? 380 default_qdisc_ops : &pfifo_fast_ops; 381 } 382 383 struct Qdisc_class_common { 384 u32 classid; 385 struct hlist_node hnode; 386 }; 387 388 struct Qdisc_class_hash { 389 struct hlist_head *hash; 390 unsigned int hashsize; 391 unsigned int hashmask; 392 unsigned int hashelems; 393 }; 394 395 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 396 { 397 id ^= id >> 8; 398 id ^= id >> 4; 399 return id & mask; 400 } 401 402 static inline struct Qdisc_class_common * 403 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 404 { 405 struct Qdisc_class_common *cl; 406 unsigned int h; 407 408 if (!id) 409 return NULL; 410 411 h = qdisc_class_hash(id, hash->hashmask); 412 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 413 if (cl->classid == id) 414 return cl; 415 } 416 return NULL; 417 } 418 419 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid) 420 { 421 u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY; 422 423 return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL; 424 } 425 426 int qdisc_class_hash_init(struct Qdisc_class_hash *); 427 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 428 struct Qdisc_class_common *); 429 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 430 struct Qdisc_class_common *); 431 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 432 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 433 434 void dev_init_scheduler(struct net_device *dev); 435 void dev_shutdown(struct net_device *dev); 436 void dev_activate(struct net_device *dev); 437 void dev_deactivate(struct net_device *dev); 438 void dev_deactivate_many(struct list_head *head); 439 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 440 struct Qdisc *qdisc); 441 void qdisc_reset(struct Qdisc *qdisc); 442 void qdisc_destroy(struct Qdisc *qdisc); 443 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 444 unsigned int len); 445 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 446 const struct Qdisc_ops *ops); 447 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 448 const struct Qdisc_ops *ops, u32 parentid); 449 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 450 const struct qdisc_size_table *stab); 451 int skb_do_redirect(struct sk_buff *); 452 453 static inline void skb_reset_tc(struct sk_buff *skb) 454 { 455 #ifdef CONFIG_NET_CLS_ACT 456 skb->tc_redirected = 0; 457 #endif 458 } 459 460 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 461 { 462 #ifdef CONFIG_NET_CLS_ACT 463 return skb->tc_at_ingress; 464 #else 465 return false; 466 #endif 467 } 468 469 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 470 { 471 #ifdef CONFIG_NET_CLS_ACT 472 if (skb->tc_skip_classify) { 473 skb->tc_skip_classify = 0; 474 return true; 475 } 476 #endif 477 return false; 478 } 479 480 /* Reset all TX qdiscs greater then index of a device. */ 481 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 482 { 483 struct Qdisc *qdisc; 484 485 for (; i < dev->num_tx_queues; i++) { 486 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 487 if (qdisc) { 488 spin_lock_bh(qdisc_lock(qdisc)); 489 qdisc_reset(qdisc); 490 spin_unlock_bh(qdisc_lock(qdisc)); 491 } 492 } 493 } 494 495 static inline void qdisc_reset_all_tx(struct net_device *dev) 496 { 497 qdisc_reset_all_tx_gt(dev, 0); 498 } 499 500 /* Are all TX queues of the device empty? */ 501 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 502 { 503 unsigned int i; 504 505 rcu_read_lock(); 506 for (i = 0; i < dev->num_tx_queues; i++) { 507 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 508 const struct Qdisc *q = rcu_dereference(txq->qdisc); 509 510 if (q->q.qlen) { 511 rcu_read_unlock(); 512 return false; 513 } 514 } 515 rcu_read_unlock(); 516 return true; 517 } 518 519 /* Are any of the TX qdiscs changing? */ 520 static inline bool qdisc_tx_changing(const struct net_device *dev) 521 { 522 unsigned int i; 523 524 for (i = 0; i < dev->num_tx_queues; i++) { 525 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 526 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 527 return true; 528 } 529 return false; 530 } 531 532 /* Is the device using the noop qdisc on all queues? */ 533 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 534 { 535 unsigned int i; 536 537 for (i = 0; i < dev->num_tx_queues; i++) { 538 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 539 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 540 return false; 541 } 542 return true; 543 } 544 545 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 546 { 547 return qdisc_skb_cb(skb)->pkt_len; 548 } 549 550 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 551 enum net_xmit_qdisc_t { 552 __NET_XMIT_STOLEN = 0x00010000, 553 __NET_XMIT_BYPASS = 0x00020000, 554 }; 555 556 #ifdef CONFIG_NET_CLS_ACT 557 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 558 #else 559 #define net_xmit_drop_count(e) (1) 560 #endif 561 562 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 563 const struct Qdisc *sch) 564 { 565 #ifdef CONFIG_NET_SCHED 566 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 567 568 if (stab) 569 __qdisc_calculate_pkt_len(skb, stab); 570 #endif 571 } 572 573 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 574 struct sk_buff **to_free) 575 { 576 qdisc_calculate_pkt_len(skb, sch); 577 return sch->enqueue(skb, sch, to_free); 578 } 579 580 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 581 { 582 return q->flags & TCQ_F_CPUSTATS; 583 } 584 585 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 586 __u64 bytes, __u32 packets) 587 { 588 bstats->bytes += bytes; 589 bstats->packets += packets; 590 } 591 592 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 593 const struct sk_buff *skb) 594 { 595 _bstats_update(bstats, 596 qdisc_pkt_len(skb), 597 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 598 } 599 600 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 601 __u64 bytes, __u32 packets) 602 { 603 u64_stats_update_begin(&bstats->syncp); 604 _bstats_update(&bstats->bstats, bytes, packets); 605 u64_stats_update_end(&bstats->syncp); 606 } 607 608 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 609 const struct sk_buff *skb) 610 { 611 u64_stats_update_begin(&bstats->syncp); 612 bstats_update(&bstats->bstats, skb); 613 u64_stats_update_end(&bstats->syncp); 614 } 615 616 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 617 const struct sk_buff *skb) 618 { 619 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 620 } 621 622 static inline void qdisc_bstats_update(struct Qdisc *sch, 623 const struct sk_buff *skb) 624 { 625 bstats_update(&sch->bstats, skb); 626 } 627 628 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 629 const struct sk_buff *skb) 630 { 631 sch->qstats.backlog -= qdisc_pkt_len(skb); 632 } 633 634 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 635 const struct sk_buff *skb) 636 { 637 sch->qstats.backlog += qdisc_pkt_len(skb); 638 } 639 640 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 641 { 642 sch->qstats.drops += count; 643 } 644 645 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 646 { 647 qstats->drops++; 648 } 649 650 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 651 { 652 qstats->overlimits++; 653 } 654 655 static inline void qdisc_qstats_drop(struct Qdisc *sch) 656 { 657 qstats_drop_inc(&sch->qstats); 658 } 659 660 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 661 { 662 this_cpu_inc(sch->cpu_qstats->drops); 663 } 664 665 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 666 { 667 sch->qstats.overlimits++; 668 } 669 670 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 671 { 672 qh->head = NULL; 673 qh->tail = NULL; 674 qh->qlen = 0; 675 } 676 677 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 678 struct qdisc_skb_head *qh) 679 { 680 struct sk_buff *last = qh->tail; 681 682 if (last) { 683 skb->next = NULL; 684 last->next = skb; 685 qh->tail = skb; 686 } else { 687 qh->tail = skb; 688 qh->head = skb; 689 } 690 qh->qlen++; 691 qdisc_qstats_backlog_inc(sch, skb); 692 693 return NET_XMIT_SUCCESS; 694 } 695 696 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 697 { 698 return __qdisc_enqueue_tail(skb, sch, &sch->q); 699 } 700 701 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 702 { 703 struct sk_buff *skb = qh->head; 704 705 if (likely(skb != NULL)) { 706 qh->head = skb->next; 707 qh->qlen--; 708 if (qh->head == NULL) 709 qh->tail = NULL; 710 skb->next = NULL; 711 } 712 713 return skb; 714 } 715 716 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 717 { 718 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 719 720 if (likely(skb != NULL)) { 721 qdisc_qstats_backlog_dec(sch, skb); 722 qdisc_bstats_update(sch, skb); 723 } 724 725 return skb; 726 } 727 728 /* Instead of calling kfree_skb() while root qdisc lock is held, 729 * queue the skb for future freeing at end of __dev_xmit_skb() 730 */ 731 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 732 { 733 skb->next = *to_free; 734 *to_free = skb; 735 } 736 737 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 738 struct qdisc_skb_head *qh, 739 struct sk_buff **to_free) 740 { 741 struct sk_buff *skb = __qdisc_dequeue_head(qh); 742 743 if (likely(skb != NULL)) { 744 unsigned int len = qdisc_pkt_len(skb); 745 746 qdisc_qstats_backlog_dec(sch, skb); 747 __qdisc_drop(skb, to_free); 748 return len; 749 } 750 751 return 0; 752 } 753 754 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 755 struct sk_buff **to_free) 756 { 757 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 758 } 759 760 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 761 { 762 const struct qdisc_skb_head *qh = &sch->q; 763 764 return qh->head; 765 } 766 767 /* generic pseudo peek method for non-work-conserving qdisc */ 768 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 769 { 770 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 771 if (!sch->gso_skb) { 772 sch->gso_skb = sch->dequeue(sch); 773 if (sch->gso_skb) { 774 /* it's still part of the queue */ 775 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 776 sch->q.qlen++; 777 } 778 } 779 780 return sch->gso_skb; 781 } 782 783 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 784 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 785 { 786 struct sk_buff *skb = sch->gso_skb; 787 788 if (skb) { 789 sch->gso_skb = NULL; 790 qdisc_qstats_backlog_dec(sch, skb); 791 sch->q.qlen--; 792 } else { 793 skb = sch->dequeue(sch); 794 } 795 796 return skb; 797 } 798 799 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 800 { 801 /* 802 * We do not know the backlog in bytes of this list, it 803 * is up to the caller to correct it 804 */ 805 ASSERT_RTNL(); 806 if (qh->qlen) { 807 rtnl_kfree_skbs(qh->head, qh->tail); 808 809 qh->head = NULL; 810 qh->tail = NULL; 811 qh->qlen = 0; 812 } 813 } 814 815 static inline void qdisc_reset_queue(struct Qdisc *sch) 816 { 817 __qdisc_reset_queue(&sch->q); 818 sch->qstats.backlog = 0; 819 } 820 821 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 822 struct Qdisc **pold) 823 { 824 struct Qdisc *old; 825 826 sch_tree_lock(sch); 827 old = *pold; 828 *pold = new; 829 if (old != NULL) { 830 unsigned int qlen = old->q.qlen; 831 unsigned int backlog = old->qstats.backlog; 832 833 qdisc_reset(old); 834 qdisc_tree_reduce_backlog(old, qlen, backlog); 835 } 836 sch_tree_unlock(sch); 837 838 return old; 839 } 840 841 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 842 { 843 rtnl_kfree_skbs(skb, skb); 844 qdisc_qstats_drop(sch); 845 } 846 847 848 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 849 struct sk_buff **to_free) 850 { 851 __qdisc_drop(skb, to_free); 852 qdisc_qstats_drop(sch); 853 854 return NET_XMIT_DROP; 855 } 856 857 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 858 long it will take to send a packet given its size. 859 */ 860 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 861 { 862 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 863 if (slot < 0) 864 slot = 0; 865 slot >>= rtab->rate.cell_log; 866 if (slot > 255) 867 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 868 return rtab->data[slot]; 869 } 870 871 struct psched_ratecfg { 872 u64 rate_bytes_ps; /* bytes per second */ 873 u32 mult; 874 u16 overhead; 875 u8 linklayer; 876 u8 shift; 877 }; 878 879 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 880 unsigned int len) 881 { 882 len += r->overhead; 883 884 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 885 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 886 887 return ((u64)len * r->mult) >> r->shift; 888 } 889 890 void psched_ratecfg_precompute(struct psched_ratecfg *r, 891 const struct tc_ratespec *conf, 892 u64 rate64); 893 894 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 895 const struct psched_ratecfg *r) 896 { 897 memset(res, 0, sizeof(*res)); 898 899 /* legacy struct tc_ratespec has a 32bit @rate field 900 * Qdisc using 64bit rate should add new attributes 901 * in order to maintain compatibility. 902 */ 903 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 904 905 res->overhead = r->overhead; 906 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 907 } 908 909 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc. 910 * The fast path only needs to access filter list and to update stats 911 */ 912 struct mini_Qdisc { 913 struct tcf_proto *filter_list; 914 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 915 struct gnet_stats_queue __percpu *cpu_qstats; 916 struct rcu_head rcu; 917 }; 918 919 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq, 920 const struct sk_buff *skb) 921 { 922 bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb); 923 } 924 925 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq) 926 { 927 this_cpu_inc(miniq->cpu_qstats->drops); 928 } 929 930 struct mini_Qdisc_pair { 931 struct mini_Qdisc miniq1; 932 struct mini_Qdisc miniq2; 933 struct mini_Qdisc __rcu **p_miniq; 934 }; 935 936 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp, 937 struct tcf_proto *tp_head); 938 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc, 939 struct mini_Qdisc __rcu **p_miniq); 940 941 #endif 942