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