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 *, unsigned long); 165 unsigned long (*bind_tcf)(struct Qdisc *, unsigned long, 166 u32 classid); 167 void (*unbind_tcf)(struct Qdisc *, unsigned long); 168 169 /* rtnetlink specific */ 170 int (*dump)(struct Qdisc *, unsigned long, 171 struct sk_buff *skb, struct tcmsg*); 172 int (*dump_stats)(struct Qdisc *, unsigned long, 173 struct gnet_dump *); 174 }; 175 176 struct Qdisc_ops { 177 struct Qdisc_ops *next; 178 const struct Qdisc_class_ops *cl_ops; 179 char id[IFNAMSIZ]; 180 int priv_size; 181 182 int (*enqueue)(struct sk_buff *skb, 183 struct Qdisc *sch, 184 struct sk_buff **to_free); 185 struct sk_buff * (*dequeue)(struct Qdisc *); 186 struct sk_buff * (*peek)(struct Qdisc *); 187 188 int (*init)(struct Qdisc *, struct nlattr *arg); 189 void (*reset)(struct Qdisc *); 190 void (*destroy)(struct Qdisc *); 191 int (*change)(struct Qdisc *, struct nlattr *arg); 192 void (*attach)(struct Qdisc *); 193 194 int (*dump)(struct Qdisc *, struct sk_buff *); 195 int (*dump_stats)(struct Qdisc *, struct gnet_dump *); 196 197 struct module *owner; 198 }; 199 200 201 struct tcf_result { 202 union { 203 struct { 204 unsigned long class; 205 u32 classid; 206 }; 207 const struct tcf_proto *goto_tp; 208 }; 209 }; 210 211 struct tcf_proto_ops { 212 struct list_head head; 213 char kind[IFNAMSIZ]; 214 215 int (*classify)(struct sk_buff *, 216 const struct tcf_proto *, 217 struct tcf_result *); 218 int (*init)(struct tcf_proto*); 219 void (*destroy)(struct tcf_proto*); 220 221 void* (*get)(struct tcf_proto*, u32 handle); 222 int (*change)(struct net *net, struct sk_buff *, 223 struct tcf_proto*, unsigned long, 224 u32 handle, struct nlattr **, 225 void **, bool); 226 int (*delete)(struct tcf_proto*, void *, bool*); 227 void (*walk)(struct tcf_proto*, struct tcf_walker *arg); 228 void (*bind_class)(void *, u32, unsigned long); 229 230 /* rtnetlink specific */ 231 int (*dump)(struct net*, struct tcf_proto*, void *, 232 struct sk_buff *skb, struct tcmsg*); 233 234 struct module *owner; 235 }; 236 237 struct tcf_proto { 238 /* Fast access part */ 239 struct tcf_proto __rcu *next; 240 void __rcu *root; 241 int (*classify)(struct sk_buff *, 242 const struct tcf_proto *, 243 struct tcf_result *); 244 __be16 protocol; 245 246 /* All the rest */ 247 u32 prio; 248 u32 classid; 249 struct Qdisc *q; 250 void *data; 251 const struct tcf_proto_ops *ops; 252 struct tcf_chain *chain; 253 struct rcu_head rcu; 254 }; 255 256 struct qdisc_skb_cb { 257 unsigned int pkt_len; 258 u16 slave_dev_queue_mapping; 259 u16 tc_classid; 260 #define QDISC_CB_PRIV_LEN 20 261 unsigned char data[QDISC_CB_PRIV_LEN]; 262 }; 263 264 typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv); 265 266 struct tcf_chain { 267 struct tcf_proto __rcu *filter_chain; 268 tcf_chain_head_change_t *chain_head_change; 269 void *chain_head_change_priv; 270 struct list_head list; 271 struct tcf_block *block; 272 u32 index; /* chain index */ 273 unsigned int refcnt; 274 }; 275 276 struct tcf_block { 277 struct list_head chain_list; 278 struct net *net; 279 struct Qdisc *q; 280 struct list_head cb_list; 281 struct work_struct work; 282 }; 283 284 static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz) 285 { 286 struct qdisc_skb_cb *qcb; 287 288 BUILD_BUG_ON(sizeof(skb->cb) < offsetof(struct qdisc_skb_cb, data) + sz); 289 BUILD_BUG_ON(sizeof(qcb->data) < sz); 290 } 291 292 static inline int qdisc_qlen(const struct Qdisc *q) 293 { 294 return q->q.qlen; 295 } 296 297 static inline struct qdisc_skb_cb *qdisc_skb_cb(const struct sk_buff *skb) 298 { 299 return (struct qdisc_skb_cb *)skb->cb; 300 } 301 302 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc) 303 { 304 return &qdisc->q.lock; 305 } 306 307 static inline struct Qdisc *qdisc_root(const struct Qdisc *qdisc) 308 { 309 struct Qdisc *q = rcu_dereference_rtnl(qdisc->dev_queue->qdisc); 310 311 return q; 312 } 313 314 static inline struct Qdisc *qdisc_root_sleeping(const struct Qdisc *qdisc) 315 { 316 return qdisc->dev_queue->qdisc_sleeping; 317 } 318 319 /* The qdisc root lock is a mechanism by which to top level 320 * of a qdisc tree can be locked from any qdisc node in the 321 * forest. This allows changing the configuration of some 322 * aspect of the qdisc tree while blocking out asynchronous 323 * qdisc access in the packet processing paths. 324 * 325 * It is only legal to do this when the root will not change 326 * on us. Otherwise we'll potentially lock the wrong qdisc 327 * root. This is enforced by holding the RTNL semaphore, which 328 * all users of this lock accessor must do. 329 */ 330 static inline spinlock_t *qdisc_root_lock(const struct Qdisc *qdisc) 331 { 332 struct Qdisc *root = qdisc_root(qdisc); 333 334 ASSERT_RTNL(); 335 return qdisc_lock(root); 336 } 337 338 static inline spinlock_t *qdisc_root_sleeping_lock(const struct Qdisc *qdisc) 339 { 340 struct Qdisc *root = qdisc_root_sleeping(qdisc); 341 342 ASSERT_RTNL(); 343 return qdisc_lock(root); 344 } 345 346 static inline seqcount_t *qdisc_root_sleeping_running(const struct Qdisc *qdisc) 347 { 348 struct Qdisc *root = qdisc_root_sleeping(qdisc); 349 350 ASSERT_RTNL(); 351 return &root->running; 352 } 353 354 static inline struct net_device *qdisc_dev(const struct Qdisc *qdisc) 355 { 356 return qdisc->dev_queue->dev; 357 } 358 359 static inline void sch_tree_lock(const struct Qdisc *q) 360 { 361 spin_lock_bh(qdisc_root_sleeping_lock(q)); 362 } 363 364 static inline void sch_tree_unlock(const struct Qdisc *q) 365 { 366 spin_unlock_bh(qdisc_root_sleeping_lock(q)); 367 } 368 369 extern struct Qdisc noop_qdisc; 370 extern struct Qdisc_ops noop_qdisc_ops; 371 extern struct Qdisc_ops pfifo_fast_ops; 372 extern struct Qdisc_ops mq_qdisc_ops; 373 extern struct Qdisc_ops noqueue_qdisc_ops; 374 extern const struct Qdisc_ops *default_qdisc_ops; 375 static inline const struct Qdisc_ops * 376 get_default_qdisc_ops(const struct net_device *dev, int ntx) 377 { 378 return ntx < dev->real_num_tx_queues ? 379 default_qdisc_ops : &pfifo_fast_ops; 380 } 381 382 struct Qdisc_class_common { 383 u32 classid; 384 struct hlist_node hnode; 385 }; 386 387 struct Qdisc_class_hash { 388 struct hlist_head *hash; 389 unsigned int hashsize; 390 unsigned int hashmask; 391 unsigned int hashelems; 392 }; 393 394 static inline unsigned int qdisc_class_hash(u32 id, u32 mask) 395 { 396 id ^= id >> 8; 397 id ^= id >> 4; 398 return id & mask; 399 } 400 401 static inline struct Qdisc_class_common * 402 qdisc_class_find(const struct Qdisc_class_hash *hash, u32 id) 403 { 404 struct Qdisc_class_common *cl; 405 unsigned int h; 406 407 if (!id) 408 return NULL; 409 410 h = qdisc_class_hash(id, hash->hashmask); 411 hlist_for_each_entry(cl, &hash->hash[h], hnode) { 412 if (cl->classid == id) 413 return cl; 414 } 415 return NULL; 416 } 417 418 static inline int tc_classid_to_hwtc(struct net_device *dev, u32 classid) 419 { 420 u32 hwtc = TC_H_MIN(classid) - TC_H_MIN_PRIORITY; 421 422 return (hwtc < netdev_get_num_tc(dev)) ? hwtc : -EINVAL; 423 } 424 425 int qdisc_class_hash_init(struct Qdisc_class_hash *); 426 void qdisc_class_hash_insert(struct Qdisc_class_hash *, 427 struct Qdisc_class_common *); 428 void qdisc_class_hash_remove(struct Qdisc_class_hash *, 429 struct Qdisc_class_common *); 430 void qdisc_class_hash_grow(struct Qdisc *, struct Qdisc_class_hash *); 431 void qdisc_class_hash_destroy(struct Qdisc_class_hash *); 432 433 void dev_init_scheduler(struct net_device *dev); 434 void dev_shutdown(struct net_device *dev); 435 void dev_activate(struct net_device *dev); 436 void dev_deactivate(struct net_device *dev); 437 void dev_deactivate_many(struct list_head *head); 438 struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue, 439 struct Qdisc *qdisc); 440 void qdisc_reset(struct Qdisc *qdisc); 441 void qdisc_destroy(struct Qdisc *qdisc); 442 void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n, 443 unsigned int len); 444 struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue, 445 const struct Qdisc_ops *ops); 446 struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue, 447 const struct Qdisc_ops *ops, u32 parentid); 448 void __qdisc_calculate_pkt_len(struct sk_buff *skb, 449 const struct qdisc_size_table *stab); 450 int skb_do_redirect(struct sk_buff *); 451 452 static inline void skb_reset_tc(struct sk_buff *skb) 453 { 454 #ifdef CONFIG_NET_CLS_ACT 455 skb->tc_redirected = 0; 456 #endif 457 } 458 459 static inline bool skb_at_tc_ingress(const struct sk_buff *skb) 460 { 461 #ifdef CONFIG_NET_CLS_ACT 462 return skb->tc_at_ingress; 463 #else 464 return false; 465 #endif 466 } 467 468 static inline bool skb_skip_tc_classify(struct sk_buff *skb) 469 { 470 #ifdef CONFIG_NET_CLS_ACT 471 if (skb->tc_skip_classify) { 472 skb->tc_skip_classify = 0; 473 return true; 474 } 475 #endif 476 return false; 477 } 478 479 /* Reset all TX qdiscs greater then index of a device. */ 480 static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) 481 { 482 struct Qdisc *qdisc; 483 484 for (; i < dev->num_tx_queues; i++) { 485 qdisc = rtnl_dereference(netdev_get_tx_queue(dev, i)->qdisc); 486 if (qdisc) { 487 spin_lock_bh(qdisc_lock(qdisc)); 488 qdisc_reset(qdisc); 489 spin_unlock_bh(qdisc_lock(qdisc)); 490 } 491 } 492 } 493 494 static inline void qdisc_reset_all_tx(struct net_device *dev) 495 { 496 qdisc_reset_all_tx_gt(dev, 0); 497 } 498 499 /* Are all TX queues of the device empty? */ 500 static inline bool qdisc_all_tx_empty(const struct net_device *dev) 501 { 502 unsigned int i; 503 504 rcu_read_lock(); 505 for (i = 0; i < dev->num_tx_queues; i++) { 506 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 507 const struct Qdisc *q = rcu_dereference(txq->qdisc); 508 509 if (q->q.qlen) { 510 rcu_read_unlock(); 511 return false; 512 } 513 } 514 rcu_read_unlock(); 515 return true; 516 } 517 518 /* Are any of the TX qdiscs changing? */ 519 static inline bool qdisc_tx_changing(const struct net_device *dev) 520 { 521 unsigned int i; 522 523 for (i = 0; i < dev->num_tx_queues; i++) { 524 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 525 if (rcu_access_pointer(txq->qdisc) != txq->qdisc_sleeping) 526 return true; 527 } 528 return false; 529 } 530 531 /* Is the device using the noop qdisc on all queues? */ 532 static inline bool qdisc_tx_is_noop(const struct net_device *dev) 533 { 534 unsigned int i; 535 536 for (i = 0; i < dev->num_tx_queues; i++) { 537 struct netdev_queue *txq = netdev_get_tx_queue(dev, i); 538 if (rcu_access_pointer(txq->qdisc) != &noop_qdisc) 539 return false; 540 } 541 return true; 542 } 543 544 static inline unsigned int qdisc_pkt_len(const struct sk_buff *skb) 545 { 546 return qdisc_skb_cb(skb)->pkt_len; 547 } 548 549 /* additional qdisc xmit flags (NET_XMIT_MASK in linux/netdevice.h) */ 550 enum net_xmit_qdisc_t { 551 __NET_XMIT_STOLEN = 0x00010000, 552 __NET_XMIT_BYPASS = 0x00020000, 553 }; 554 555 #ifdef CONFIG_NET_CLS_ACT 556 #define net_xmit_drop_count(e) ((e) & __NET_XMIT_STOLEN ? 0 : 1) 557 #else 558 #define net_xmit_drop_count(e) (1) 559 #endif 560 561 static inline void qdisc_calculate_pkt_len(struct sk_buff *skb, 562 const struct Qdisc *sch) 563 { 564 #ifdef CONFIG_NET_SCHED 565 struct qdisc_size_table *stab = rcu_dereference_bh(sch->stab); 566 567 if (stab) 568 __qdisc_calculate_pkt_len(skb, stab); 569 #endif 570 } 571 572 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch, 573 struct sk_buff **to_free) 574 { 575 qdisc_calculate_pkt_len(skb, sch); 576 return sch->enqueue(skb, sch, to_free); 577 } 578 579 static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) 580 { 581 return q->flags & TCQ_F_CPUSTATS; 582 } 583 584 static inline void _bstats_update(struct gnet_stats_basic_packed *bstats, 585 __u64 bytes, __u32 packets) 586 { 587 bstats->bytes += bytes; 588 bstats->packets += packets; 589 } 590 591 static inline void bstats_update(struct gnet_stats_basic_packed *bstats, 592 const struct sk_buff *skb) 593 { 594 _bstats_update(bstats, 595 qdisc_pkt_len(skb), 596 skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1); 597 } 598 599 static inline void _bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 600 __u64 bytes, __u32 packets) 601 { 602 u64_stats_update_begin(&bstats->syncp); 603 _bstats_update(&bstats->bstats, bytes, packets); 604 u64_stats_update_end(&bstats->syncp); 605 } 606 607 static inline void bstats_cpu_update(struct gnet_stats_basic_cpu *bstats, 608 const struct sk_buff *skb) 609 { 610 u64_stats_update_begin(&bstats->syncp); 611 bstats_update(&bstats->bstats, skb); 612 u64_stats_update_end(&bstats->syncp); 613 } 614 615 static inline void qdisc_bstats_cpu_update(struct Qdisc *sch, 616 const struct sk_buff *skb) 617 { 618 bstats_cpu_update(this_cpu_ptr(sch->cpu_bstats), skb); 619 } 620 621 static inline void qdisc_bstats_update(struct Qdisc *sch, 622 const struct sk_buff *skb) 623 { 624 bstats_update(&sch->bstats, skb); 625 } 626 627 static inline void qdisc_qstats_backlog_dec(struct Qdisc *sch, 628 const struct sk_buff *skb) 629 { 630 sch->qstats.backlog -= qdisc_pkt_len(skb); 631 } 632 633 static inline void qdisc_qstats_backlog_inc(struct Qdisc *sch, 634 const struct sk_buff *skb) 635 { 636 sch->qstats.backlog += qdisc_pkt_len(skb); 637 } 638 639 static inline void __qdisc_qstats_drop(struct Qdisc *sch, int count) 640 { 641 sch->qstats.drops += count; 642 } 643 644 static inline void qstats_drop_inc(struct gnet_stats_queue *qstats) 645 { 646 qstats->drops++; 647 } 648 649 static inline void qstats_overlimit_inc(struct gnet_stats_queue *qstats) 650 { 651 qstats->overlimits++; 652 } 653 654 static inline void qdisc_qstats_drop(struct Qdisc *sch) 655 { 656 qstats_drop_inc(&sch->qstats); 657 } 658 659 static inline void qdisc_qstats_cpu_drop(struct Qdisc *sch) 660 { 661 this_cpu_inc(sch->cpu_qstats->drops); 662 } 663 664 static inline void qdisc_qstats_overlimit(struct Qdisc *sch) 665 { 666 sch->qstats.overlimits++; 667 } 668 669 static inline void qdisc_skb_head_init(struct qdisc_skb_head *qh) 670 { 671 qh->head = NULL; 672 qh->tail = NULL; 673 qh->qlen = 0; 674 } 675 676 static inline int __qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch, 677 struct qdisc_skb_head *qh) 678 { 679 struct sk_buff *last = qh->tail; 680 681 if (last) { 682 skb->next = NULL; 683 last->next = skb; 684 qh->tail = skb; 685 } else { 686 qh->tail = skb; 687 qh->head = skb; 688 } 689 qh->qlen++; 690 qdisc_qstats_backlog_inc(sch, skb); 691 692 return NET_XMIT_SUCCESS; 693 } 694 695 static inline int qdisc_enqueue_tail(struct sk_buff *skb, struct Qdisc *sch) 696 { 697 return __qdisc_enqueue_tail(skb, sch, &sch->q); 698 } 699 700 static inline struct sk_buff *__qdisc_dequeue_head(struct qdisc_skb_head *qh) 701 { 702 struct sk_buff *skb = qh->head; 703 704 if (likely(skb != NULL)) { 705 qh->head = skb->next; 706 qh->qlen--; 707 if (qh->head == NULL) 708 qh->tail = NULL; 709 skb->next = NULL; 710 } 711 712 return skb; 713 } 714 715 static inline struct sk_buff *qdisc_dequeue_head(struct Qdisc *sch) 716 { 717 struct sk_buff *skb = __qdisc_dequeue_head(&sch->q); 718 719 if (likely(skb != NULL)) { 720 qdisc_qstats_backlog_dec(sch, skb); 721 qdisc_bstats_update(sch, skb); 722 } 723 724 return skb; 725 } 726 727 /* Instead of calling kfree_skb() while root qdisc lock is held, 728 * queue the skb for future freeing at end of __dev_xmit_skb() 729 */ 730 static inline void __qdisc_drop(struct sk_buff *skb, struct sk_buff **to_free) 731 { 732 skb->next = *to_free; 733 *to_free = skb; 734 } 735 736 static inline unsigned int __qdisc_queue_drop_head(struct Qdisc *sch, 737 struct qdisc_skb_head *qh, 738 struct sk_buff **to_free) 739 { 740 struct sk_buff *skb = __qdisc_dequeue_head(qh); 741 742 if (likely(skb != NULL)) { 743 unsigned int len = qdisc_pkt_len(skb); 744 745 qdisc_qstats_backlog_dec(sch, skb); 746 __qdisc_drop(skb, to_free); 747 return len; 748 } 749 750 return 0; 751 } 752 753 static inline unsigned int qdisc_queue_drop_head(struct Qdisc *sch, 754 struct sk_buff **to_free) 755 { 756 return __qdisc_queue_drop_head(sch, &sch->q, to_free); 757 } 758 759 static inline struct sk_buff *qdisc_peek_head(struct Qdisc *sch) 760 { 761 const struct qdisc_skb_head *qh = &sch->q; 762 763 return qh->head; 764 } 765 766 /* generic pseudo peek method for non-work-conserving qdisc */ 767 static inline struct sk_buff *qdisc_peek_dequeued(struct Qdisc *sch) 768 { 769 /* we can reuse ->gso_skb because peek isn't called for root qdiscs */ 770 if (!sch->gso_skb) { 771 sch->gso_skb = sch->dequeue(sch); 772 if (sch->gso_skb) { 773 /* it's still part of the queue */ 774 qdisc_qstats_backlog_inc(sch, sch->gso_skb); 775 sch->q.qlen++; 776 } 777 } 778 779 return sch->gso_skb; 780 } 781 782 /* use instead of qdisc->dequeue() for all qdiscs queried with ->peek() */ 783 static inline struct sk_buff *qdisc_dequeue_peeked(struct Qdisc *sch) 784 { 785 struct sk_buff *skb = sch->gso_skb; 786 787 if (skb) { 788 sch->gso_skb = NULL; 789 qdisc_qstats_backlog_dec(sch, skb); 790 sch->q.qlen--; 791 } else { 792 skb = sch->dequeue(sch); 793 } 794 795 return skb; 796 } 797 798 static inline void __qdisc_reset_queue(struct qdisc_skb_head *qh) 799 { 800 /* 801 * We do not know the backlog in bytes of this list, it 802 * is up to the caller to correct it 803 */ 804 ASSERT_RTNL(); 805 if (qh->qlen) { 806 rtnl_kfree_skbs(qh->head, qh->tail); 807 808 qh->head = NULL; 809 qh->tail = NULL; 810 qh->qlen = 0; 811 } 812 } 813 814 static inline void qdisc_reset_queue(struct Qdisc *sch) 815 { 816 __qdisc_reset_queue(&sch->q); 817 sch->qstats.backlog = 0; 818 } 819 820 static inline struct Qdisc *qdisc_replace(struct Qdisc *sch, struct Qdisc *new, 821 struct Qdisc **pold) 822 { 823 struct Qdisc *old; 824 825 sch_tree_lock(sch); 826 old = *pold; 827 *pold = new; 828 if (old != NULL) { 829 unsigned int qlen = old->q.qlen; 830 unsigned int backlog = old->qstats.backlog; 831 832 qdisc_reset(old); 833 qdisc_tree_reduce_backlog(old, qlen, backlog); 834 } 835 sch_tree_unlock(sch); 836 837 return old; 838 } 839 840 static inline void rtnl_qdisc_drop(struct sk_buff *skb, struct Qdisc *sch) 841 { 842 rtnl_kfree_skbs(skb, skb); 843 qdisc_qstats_drop(sch); 844 } 845 846 847 static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch, 848 struct sk_buff **to_free) 849 { 850 __qdisc_drop(skb, to_free); 851 qdisc_qstats_drop(sch); 852 853 return NET_XMIT_DROP; 854 } 855 856 /* Length to Time (L2T) lookup in a qdisc_rate_table, to determine how 857 long it will take to send a packet given its size. 858 */ 859 static inline u32 qdisc_l2t(struct qdisc_rate_table* rtab, unsigned int pktlen) 860 { 861 int slot = pktlen + rtab->rate.cell_align + rtab->rate.overhead; 862 if (slot < 0) 863 slot = 0; 864 slot >>= rtab->rate.cell_log; 865 if (slot > 255) 866 return rtab->data[255]*(slot >> 8) + rtab->data[slot & 0xFF]; 867 return rtab->data[slot]; 868 } 869 870 struct psched_ratecfg { 871 u64 rate_bytes_ps; /* bytes per second */ 872 u32 mult; 873 u16 overhead; 874 u8 linklayer; 875 u8 shift; 876 }; 877 878 static inline u64 psched_l2t_ns(const struct psched_ratecfg *r, 879 unsigned int len) 880 { 881 len += r->overhead; 882 883 if (unlikely(r->linklayer == TC_LINKLAYER_ATM)) 884 return ((u64)(DIV_ROUND_UP(len,48)*53) * r->mult) >> r->shift; 885 886 return ((u64)len * r->mult) >> r->shift; 887 } 888 889 void psched_ratecfg_precompute(struct psched_ratecfg *r, 890 const struct tc_ratespec *conf, 891 u64 rate64); 892 893 static inline void psched_ratecfg_getrate(struct tc_ratespec *res, 894 const struct psched_ratecfg *r) 895 { 896 memset(res, 0, sizeof(*res)); 897 898 /* legacy struct tc_ratespec has a 32bit @rate field 899 * Qdisc using 64bit rate should add new attributes 900 * in order to maintain compatibility. 901 */ 902 res->rate = min_t(u64, r->rate_bytes_ps, ~0U); 903 904 res->overhead = r->overhead; 905 res->linklayer = (r->linklayer & TC_LINKLAYER_MASK); 906 } 907 908 /* Mini Qdisc serves for specific needs of ingress/clsact Qdisc. 909 * The fast path only needs to access filter list and to update stats 910 */ 911 struct mini_Qdisc { 912 struct tcf_proto *filter_list; 913 struct gnet_stats_basic_cpu __percpu *cpu_bstats; 914 struct gnet_stats_queue __percpu *cpu_qstats; 915 struct rcu_head rcu; 916 }; 917 918 static inline void mini_qdisc_bstats_cpu_update(struct mini_Qdisc *miniq, 919 const struct sk_buff *skb) 920 { 921 bstats_cpu_update(this_cpu_ptr(miniq->cpu_bstats), skb); 922 } 923 924 static inline void mini_qdisc_qstats_cpu_drop(struct mini_Qdisc *miniq) 925 { 926 this_cpu_inc(miniq->cpu_qstats->drops); 927 } 928 929 struct mini_Qdisc_pair { 930 struct mini_Qdisc miniq1; 931 struct mini_Qdisc miniq2; 932 struct mini_Qdisc __rcu **p_miniq; 933 }; 934 935 void mini_qdisc_pair_swap(struct mini_Qdisc_pair *miniqp, 936 struct tcf_proto *tp_head); 937 void mini_qdisc_pair_init(struct mini_Qdisc_pair *miniqp, struct Qdisc *qdisc, 938 struct mini_Qdisc __rcu **p_miniq); 939 940 #endif 941