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1 #ifndef _LINUX_LIST_H 2 #define _LINUX_LIST_H 3 4 struct list_head { 5 struct list_head *next, *prev; 6 }; 7 8 struct hlist_head { 9 struct hlist_node *first; 10 }; 11 12 struct hlist_node { 13 struct hlist_node *next, **pprev; 14 }; 15 16 #ifndef offsetof 17 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) 18 #endif 19 20 #ifndef container_of 21 /** 22 * container_of - cast a member of a structure out to the containing structure 23 * @ptr: the pointer to the member. 24 * @type: the type of the container struct this is embedded in. 25 * @member: the name of the member within the struct. 26 * 27 */ 28 #define container_of(ptr, type, member) ({ 29 const typeof(((type *)0)->member) * __mptr = (ptr); 30 (type *)((char *)__mptr - offsetof(type, member)); }) 31 #endif 32 33 #define LIST_POISON1 NULL 34 #define LIST_POISON2 NULL 35 36 /* 37 * Simple doubly linked list implementation. 38 * 39 * Some of the internal functions ("__xxx") are useful when 40 * manipulating whole lists rather than single entries, as 41 * sometimes we already know the next/prev entries and we can 42 * generate better code by using them directly rather than 43 * using the generic single-entry routines. 44 */ 45 46 #define LIST_HEAD_INIT(name) { &(name), &(name) } 47 48 #define LIST_HEAD(name) 49 struct list_head name = LIST_HEAD_INIT(name) 50 51 static inline void INIT_LIST_HEAD(struct list_head *list) 52 { 53 list->next = list; 54 list->prev = list; 55 } 56 57 /* 58 * Insert a new entry between two known consecutive entries. 59 * 60 * This is only for internal list manipulation where we know 61 * the prev/next entries already! 62 */ 63 #ifndef CONFIG_DEBUG_LIST 64 static inline void __list_add(struct list_head *new, 65 struct list_head *prev, 66 struct list_head *next) 67 { 68 next->prev = new; 69 new->next = next; 70 new->prev = prev; 71 prev->next = new; 72 } 73 #else 74 extern void __list_add(struct list_head *new, 75 struct list_head *prev, 76 struct list_head *next); 77 #endif 78 79 /** 80 * list_add - add a new entry 81 * @new: new entry to be added 82 * @head: list head to add it after 83 * 84 * Insert a new entry after the specified head. 85 * This is good for implementing stacks. 86 */ 87 static inline void list_add(struct list_head *new, struct list_head *head) 88 { 89 __list_add(new, head, head->next); 90 } 91 92 93 /** 94 * list_add_tail - add a new entry 95 * @new: new entry to be added 96 * @head: list head to add it before 97 * 98 * Insert a new entry before the specified head. 99 * This is useful for implementing queues. 100 */ 101 static inline void list_add_tail(struct list_head *new, struct list_head *head) 102 { 103 __list_add(new, head->prev, head); 104 } 105 106 /* 107 * Delete a list entry by making the prev/next entries 108 * point to each other. 109 * 110 * This is only for internal list manipulation where we know 111 * the prev/next entries already! 112 */ 113 static inline void __list_del(struct list_head * prev, struct list_head * next) 114 { 115 next->prev = prev; 116 prev->next = next; 117 } 118 119 /** 120 * list_del - deletes entry from list. 121 * @entry: the element to delete from the list. 122 * Note: list_empty() on entry does not return true after this, the entry is 123 * in an undefined state. 124 */ 125 #ifndef CONFIG_DEBUG_LIST 126 static inline void __list_del_entry(struct list_head *entry) 127 { 128 __list_del(entry->prev, entry->next); 129 } 130 131 static inline void list_del(struct list_head *entry) 132 { 133 __list_del(entry->prev, entry->next); 134 entry->next = LIST_POISON1; 135 entry->prev = LIST_POISON2; 136 } 137 #else 138 extern void __list_del_entry(struct list_head *entry); 139 extern void list_del(struct list_head *entry); 140 #endif 141 142 /** 143 * list_replace - replace old entry by new one 144 * @old : the element to be replaced 145 * @new : the new element to insert 146 * 147 * If @old was empty, it will be overwritten. 148 */ 149 static inline void list_replace(struct list_head *old, 150 struct list_head *new) 151 { 152 new->next = old->next; 153 new->next->prev = new; 154 new->prev = old->prev; 155 new->prev->next = new; 156 } 157 158 static inline void list_replace_init(struct list_head *old, 159 struct list_head *new) 160 { 161 list_replace(old, new); 162 INIT_LIST_HEAD(old); 163 } 164 165 /** 166 * list_del_init - deletes entry from list and reinitialize it. 167 * @entry: the element to delete from the list. 168 */ 169 static inline void list_del_init(struct list_head *entry) 170 { 171 __list_del_entry(entry); 172 INIT_LIST_HEAD(entry); 173 } 174 175 /** 176 * list_move - delete from one list and add as another‘s head 177 * @list: the entry to move 178 * @head: the head that will precede our entry 179 */ 180 static inline void list_move(struct list_head *list, struct list_head *head) 181 { 182 __list_del_entry(list); 183 list_add(list, head); 184 } 185 186 /** 187 * list_move_tail - delete from one list and add as another‘s tail 188 * @list: the entry to move 189 * @head: the head that will follow our entry 190 */ 191 static inline void list_move_tail(struct list_head *list, 192 struct list_head *head) 193 { 194 __list_del_entry(list); 195 list_add_tail(list, head); 196 } 197 198 /** 199 * list_is_last - tests whether @list is the last entry in list @head 200 * @list: the entry to test 201 * @head: the head of the list 202 */ 203 static inline int list_is_last(const struct list_head *list, 204 const struct list_head *head) 205 { 206 return list->next == head; 207 } 208 209 /** 210 * list_empty - tests whether a list is empty 211 * @head: the list to test. 212 */ 213 static inline int list_empty(const struct list_head *head) 214 { 215 return head->next == head; 216 } 217 218 /** 219 * list_empty_careful - tests whether a list is empty and not being modified 220 * @head: the list to test 221 * 222 * Description: 223 * tests whether a list is empty _and_ checks that no other CPU might be 224 * in the process of modifying either member (next or prev) 225 * 226 * NOTE: using list_empty_careful() without synchronization 227 * can only be safe if the only activity that can happen 228 * to the list entry is list_del_init(). Eg. it cannot be used 229 * if another CPU could re-list_add() it. 230 */ 231 static inline int list_empty_careful(const struct list_head *head) 232 { 233 struct list_head *next = head->next; 234 return (next == head) && (next == head->prev); 235 } 236 237 /** 238 * list_rotate_left - rotate the list to the left 239 * @head: the head of the list 240 */ 241 static inline void list_rotate_left(struct list_head *head) 242 { 243 struct list_head *first; 244 245 if (!list_empty(head)) { 246 first = head->next; 247 list_move_tail(first, head); 248 } 249 } 250 251 /** 252 * list_is_singular - tests whether a list has just one entry. 253 * @head: the list to test. 254 */ 255 static inline int list_is_singular(const struct list_head *head) 256 { 257 return !list_empty(head) && (head->next == head->prev); 258 } 259 260 static inline void __list_cut_position(struct list_head *list, 261 struct list_head *head, struct list_head *entry) 262 { 263 struct list_head *new_first = entry->next; 264 list->next = head->next; 265 list->next->prev = list; 266 list->prev = entry; 267 entry->next = list; 268 head->next = new_first; 269 new_first->prev = head; 270 } 271 272 /** 273 * list_cut_position - cut a list into two 274 * @list: a new list to add all removed entries 275 * @head: a list with entries 276 * @entry: an entry within head, could be the head itself 277 * and if so we won‘t cut the list 278 * 279 * This helper moves the initial part of @head, up to and 280 * including @entry, from @head to @list. You should 281 * pass on @entry an element you know is on @head. @list 282 * should be an empty list or a list you do not care about 283 * losing its data. 284 * 285 */ 286 static inline void list_cut_position(struct list_head *list, 287 struct list_head *head, struct list_head *entry) 288 { 289 if (list_empty(head)) 290 return; 291 if (list_is_singular(head) && 292 (head->next != entry && head != entry)) 293 return; 294 if (entry == head) 295 INIT_LIST_HEAD(list); 296 else 297 __list_cut_position(list, head, entry); 298 } 299 300 static inline void __list_splice(const struct list_head *list, 301 struct list_head *prev, 302 struct list_head *next) 303 { 304 struct list_head *first = list->next; 305 struct list_head *last = list->prev; 306 307 first->prev = prev; 308 prev->next = first; 309 310 last->next = next; 311 next->prev = last; 312 } 313 314 /** 315 * list_splice - join two lists, this is designed for stacks 316 * @list: the new list to add. 317 * @head: the place to add it in the first list. 318 */ 319 static inline void list_splice(const struct list_head *list, 320 struct list_head *head) 321 { 322 if (!list_empty(list)) 323 __list_splice(list, head, head->next); 324 } 325 326 /** 327 * list_splice_tail - join two lists, each list being a queue 328 * @list: the new list to add. 329 * @head: the place to add it in the first list. 330 */ 331 static inline void list_splice_tail(struct list_head *list, 332 struct list_head *head) 333 { 334 if (!list_empty(list)) 335 __list_splice(list, head->prev, head); 336 } 337 338 /** 339 * list_splice_init - join two lists and reinitialise the emptied list. 340 * @list: the new list to add. 341 * @head: the place to add it in the first list. 342 * 343 * The list at @list is reinitialised 344 */ 345 static inline void list_splice_init(struct list_head *list, 346 struct list_head *head) 347 { 348 if (!list_empty(list)) { 349 __list_splice(list, head, head->next); 350 INIT_LIST_HEAD(list); 351 } 352 } 353 354 /** 355 * list_splice_tail_init - join two lists and reinitialise the emptied list 356 * @list: the new list to add. 357 * @head: the place to add it in the first list. 358 * 359 * Each of the lists is a queue. 360 * The list at @list is reinitialised 361 */ 362 static inline void list_splice_tail_init(struct list_head *list, 363 struct list_head *head) 364 { 365 if (!list_empty(list)) { 366 __list_splice(list, head->prev, head); 367 INIT_LIST_HEAD(list); 368 } 369 } 370 371 /** 372 * list_entry - get the struct for this entry 373 * @ptr: the &struct list_head pointer. 374 * @type: the type of the struct this is embedded in. 375 * @member: the name of the list_struct within the struct. 376 */ 377 #define list_entry(ptr, type, member) 378 container_of(ptr, type, member) 379 380 /** 381 * list_first_entry - get the first element from a list 382 * @ptr: the list head to take the element from. 383 * @type: the type of the struct this is embedded in. 384 * @member: the name of the list_struct within the struct. 385 * 386 * Note, that list is expected to be not empty. 387 */ 388 #define list_first_entry(ptr, type, member) 389 list_entry((ptr)->next, type, member) 390 391 /** 392 * list_for_each - iterate over a list 393 * @pos: the &struct list_head to use as a loop cursor. 394 * @head: the head for your list. 395 */ 396 #define list_for_each(pos, head) 397 for (pos = (head)->next; pos != (head); pos = pos->next) 398 399 /** 400 * __list_for_each - iterate over a list 401 * @pos: the &struct list_head to use as a loop cursor. 402 * @head: the head for your list. 403 * 404 * This variant doesn‘t differ from list_for_each() any more. 405 * We don‘t do prefetching in either case. 406 */ 407 #define __list_for_each(pos, head) 408 for (pos = (head)->next; pos != (head); pos = pos->next) 409 410 /** 411 * list_for_each_prev - iterate over a list backwards 412 * @pos: the &struct list_head to use as a loop cursor. 413 * @head: the head for your list. 414 */ 415 #define list_for_each_prev(pos, head) 416 for (pos = (head)->prev; pos != (head); pos = pos->prev) 417 418 /** 419 * list_for_each_safe - iterate over a list safe against removal of list entry 420 * @pos: the &struct list_head to use as a loop cursor. 421 * @n: another &struct list_head to use as temporary storage 422 * @head: the head for your list. 423 */ 424 #define list_for_each_safe(pos, n, head) 425 for (pos = (head)->next, n = pos->next; pos != (head); 426 pos = n, n = pos->next) 427 428 /** 429 * list_for_each_prev_safe - iterate over a list backwards safe against removal of list entry 430 * @pos: the &struct list_head to use as a loop cursor. 431 * @n: another &struct list_head to use as temporary storage 432 * @head: the head for your list. 433 */ 434 #define list_for_each_prev_safe(pos, n, head) 435 for (pos = (head)->prev, n = pos->prev; 436 pos != (head); 437 pos = n, n = pos->prev) 438 439 /** 440 * list_for_each_entry - iterate over list of given type 441 * @pos: the type * to use as a loop cursor. 442 * @head: the head for your list. 443 * @member: the name of the list_struct within the struct. 444 */ 445 #define list_for_each_entry(pos, head, member) 446 for (pos = list_entry((head)->next, typeof(*pos), member); 447 &pos->member != (head); 448 pos = list_entry(pos->member.next, typeof(*pos), member)) 449 450 /** 451 * list_for_each_entry_reverse - iterate backwards over list of given type. 452 * @pos: the type * to use as a loop cursor. 453 * @head: the head for your list. 454 * @member: the name of the list_struct within the struct. 455 */ 456 #define list_for_each_entry_reverse(pos, head, member) 457 for (pos = list_entry((head)->prev, typeof(*pos), member); 458 &pos->member != (head); 459 pos = list_entry(pos->member.prev, typeof(*pos), member)) 460 461 /** 462 * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue() 463 * @pos: the type * to use as a start point 464 * @head: the head of the list 465 * @member: the name of the list_struct within the struct. 466 * 467 * Prepares a pos entry for use as a start point in list_for_each_entry_continue(). 468 */ 469 #define list_prepare_entry(pos, head, member) 470 ((pos) ? : list_entry(head, typeof(*pos), member)) 471 472 /** 473 * list_for_each_entry_continue - continue iteration over list of given type 474 * @pos: the type * to use as a loop cursor. 475 * @head: the head for your list. 476 * @member: the name of the list_struct within the struct. 477 * 478 * Continue to iterate over list of given type, continuing after 479 * the current position. 480 */ 481 #define list_for_each_entry_continue(pos, head, member) 482 for (pos = list_entry(pos->member.next, typeof(*pos), member); 483 &pos->member != (head); 484 pos = list_entry(pos->member.next, typeof(*pos), member)) 485 486 /** 487 * list_for_each_entry_continue_reverse - iterate backwards from the given point 488 * @pos: the type * to use as a loop cursor. 489 * @head: the head for your list. 490 * @member: the name of the list_struct within the struct. 491 * 492 * Start to iterate over list of given type backwards, continuing after 493 * the current position. 494 */ 495 #define list_for_each_entry_continue_reverse(pos, head, member) 496 for (pos = list_entry(pos->member.prev, typeof(*pos), member); 497 &pos->member != (head); 498 pos = list_entry(pos->member.prev, typeof(*pos), member)) 499 500 /** 501 * list_for_each_entry_from - iterate over list of given type from the current point 502 * @pos: the type * to use as a loop cursor. 503 * @head: the head for your list. 504 * @member: the name of the list_struct within the struct. 505 * 506 * Iterate over list of given type, continuing from current position. 507 */ 508 #define list_for_each_entry_from(pos, head, member) 509 for (; &pos->member != (head); 510 pos = list_entry(pos->member.next, typeof(*pos), member)) 511 512 /** 513 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry 514 * @pos: the type * to use as a loop cursor. 515 * @n: another type * to use as temporary storage 516 * @head: the head for your list. 517 * @member: the name of the list_struct within the struct. 518 */ 519 #define list_for_each_entry_safe(pos, n, head, member) 520 for (pos = list_entry((head)->next, typeof(*pos), member), 521 n = list_entry(pos->member.next, typeof(*pos), member); 522 &pos->member != (head); 523 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 524 525 /** 526 * list_for_each_entry_safe_continue - continue list iteration safe against removal 527 * @pos: the type * to use as a loop cursor. 528 * @n: another type * to use as temporary storage 529 * @head: the head for your list. 530 * @member: the name of the list_struct within the struct. 531 * 532 * Iterate over list of given type, continuing after current point, 533 * safe against removal of list entry. 534 */ 535 #define list_for_each_entry_safe_continue(pos, n, head, member) 536 for (pos = list_entry(pos->member.next, typeof(*pos), member), 537 n = list_entry(pos->member.next, typeof(*pos), member); 538 &pos->member != (head); 539 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 540 541 /** 542 * list_for_each_entry_safe_from - iterate over list from current point safe against removal 543 * @pos: the type * to use as a loop cursor. 544 * @n: another type * to use as temporary storage 545 * @head: the head for your list. 546 * @member: the name of the list_struct within the struct. 547 * 548 * Iterate over list of given type from current point, safe against 549 * removal of list entry. 550 */ 551 #define list_for_each_entry_safe_from(pos, n, head, member) 552 for (n = list_entry(pos->member.next, typeof(*pos), member); 553 &pos->member != (head); 554 pos = n, n = list_entry(n->member.next, typeof(*n), member)) 555 556 /** 557 * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal 558 * @pos: the type * to use as a loop cursor. 559 * @n: another type * to use as temporary storage 560 * @head: the head for your list. 561 * @member: the name of the list_struct within the struct. 562 * 563 * Iterate backwards over list of given type, safe against removal 564 * of list entry. 565 */ 566 #define list_for_each_entry_safe_reverse(pos, n, head, member) 567 for (pos = list_entry((head)->prev, typeof(*pos), member), 568 n = list_entry(pos->member.prev, typeof(*pos), member); 569 &pos->member != (head); 570 pos = n, n = list_entry(n->member.prev, typeof(*n), member)) 571 572 /** 573 * list_safe_reset_next - reset a stale list_for_each_entry_safe loop 574 * @pos: the loop cursor used in the list_for_each_entry_safe loop 575 * @n: temporary storage used in list_for_each_entry_safe 576 * @member: the name of the list_struct within the struct. 577 * 578 * list_safe_reset_next is not safe to use in general if the list may be 579 * modified concurrently (eg. the lock is dropped in the loop body). An 580 * exception to this is if the cursor element (pos) is pinned in the list, 581 * and list_safe_reset_next is called after re-taking the lock and before 582 * completing the current iteration of the loop body. 583 */ 584 #define list_safe_reset_next(pos, n, member) 585 n = list_entry(pos->member.next, typeof(*pos), member) 586 587 /* 588 * Double linked lists with a single pointer list head. 589 * Mostly useful for hash tables where the two pointer list head is 590 * too wasteful. 591 * You lose the ability to access the tail in O(1). 592 */ 593 594 #define HLIST_HEAD_INIT { .first = NULL } 595 #define HLIST_HEAD(name) struct hlist_head name = { .first = NULL } 596 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL) 597 static inline void INIT_HLIST_NODE(struct hlist_node *h) 598 { 599 h->next = NULL; 600 h->pprev = NULL; 601 } 602 603 static inline int hlist_unhashed(const struct hlist_node *h) 604 { 605 return !h->pprev; 606 } 607 608 static inline int hlist_empty(const struct hlist_head *h) 609 { 610 return !h->first; 611 } 612 613 static inline void __hlist_del(struct hlist_node *n) 614 { 615 struct hlist_node *next = n->next; 616 struct hlist_node **pprev = n->pprev; 617 *pprev = next; 618 if (next) 619 next->pprev = pprev; 620 } 621 622 static inline void hlist_del(struct hlist_node *n) 623 { 624 __hlist_del(n); 625 n->next = LIST_POISON1; 626 n->pprev = LIST_POISON2; 627 } 628 629 static inline void hlist_del_init(struct hlist_node *n) 630 { 631 if (!hlist_unhashed(n)) { 632 __hlist_del(n); 633 INIT_HLIST_NODE(n); 634 } 635 } 636 637 static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h) 638 { 639 struct hlist_node *first = h->first; 640 n->next = first; 641 if (first) 642 first->pprev = &n->next; 643 h->first = n; 644 n->pprev = &h->first; 645 } 646 647 /* next must be != NULL */ 648 static inline void hlist_add_before(struct hlist_node *n, 649 struct hlist_node *next) 650 { 651 n->pprev = next->pprev; 652 n->next = next; 653 next->pprev = &n->next; 654 *(n->pprev) = n; 655 } 656 657 static inline void hlist_add_after(struct hlist_node *n, 658 struct hlist_node *next) 659 { 660 next->next = n->next; 661 n->next = next; 662 next->pprev = &n->next; 663 664 if(next->next) 665 next->next->pprev = &next->next; 666 } 667 668 /* after that we‘ll appear to be on some hlist and hlist_del will work */ 669 static inline void hlist_add_fake(struct hlist_node *n) 670 { 671 n->pprev = &n->next; 672 } 673 674 /* 675 * Move a list from one list head to another. Fixup the pprev 676 * reference of the first entry if it exists. 677 */ 678 static inline void hlist_move_list(struct hlist_head *old, 679 struct hlist_head *new) 680 { 681 new->first = old->first; 682 if (new->first) 683 new->first->pprev = &new->first; 684 old->first = NULL; 685 } 686 687 #define hlist_entry(ptr, type, member) container_of(ptr,type,member) 688 689 #define hlist_for_each(pos, head) 690 for (pos = (head)->first; pos ; pos = pos->next) 691 692 #define hlist_for_each_safe(pos, n, head) 693 for (pos = (head)->first; pos && ({ n = pos->next; 1; }); 694 pos = n) 695 696 /** 697 * hlist_for_each_entry - iterate over list of given type 698 * @tpos: the type * to use as a loop cursor. 699 * @pos: the &struct hlist_node to use as a loop cursor. 700 * @head: the head for your list. 701 * @member: the name of the hlist_node within the struct. 702 */ 703 #define hlist_for_each_entry(tpos, pos, head, member) 704 for (pos = (head)->first; 705 pos && 706 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 707 pos = pos->next) 708 709 /** 710 * hlist_for_each_entry_continue - iterate over a hlist continuing after current point 711 * @tpos: the type * to use as a loop cursor. 712 * @pos: the &struct hlist_node to use as a loop cursor. 713 * @member: the name of the hlist_node within the struct. 714 */ 715 #define hlist_for_each_entry_continue(tpos, pos, member) 716 for (pos = (pos)->next; 717 pos && 718 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 719 pos = pos->next) 720 721 /** 722 * hlist_for_each_entry_from - iterate over a hlist continuing from current point 723 * @tpos: the type * to use as a loop cursor. 724 * @pos: the &struct hlist_node to use as a loop cursor. 725 * @member: the name of the hlist_node within the struct. 726 */ 727 #define hlist_for_each_entry_from(tpos, pos, member) 728 for (; pos && 729 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 730 pos = pos->next) 731 732 /** 733 * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry 734 * @tpos: the type * to use as a loop cursor. 735 * @pos: the &struct hlist_node to use as a loop cursor. 736 * @n: another &struct hlist_node to use as temporary storage 737 * @head: the head for your list. 738 * @member: the name of the hlist_node within the struct. 739 */ 740 #define hlist_for_each_entry_safe(tpos, pos, n, head, member) 741 for (pos = (head)->first; 742 pos && ({ n = pos->next; 1; }) && 743 ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); 744 pos = n) 745 746 #endif
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原文地址：http://www.cnblogs.com/gaoningbo/p/5879944.html
