release/src/router/busybox/e2fsprogs/old_e2fsprogs/ext2fs/kernel-list.h

   1 /* vi: set sw=4 ts=4: */
   2 #ifndef LINUX_LIST_H
   3 #define LINUX_LIST_H 1
   4
   5 /*
   6  * Simple doubly linked list implementation.
   7  *
   8  * Some of the internal functions ("__xxx") are useful when
   9  * manipulating whole lists rather than single entries, as
  10  * sometimes we already know the next/prev entries and we can
  11  * generate better code by using them directly rather than
  12  * using the generic single-entry routines.
  13  */
  14
  15 struct list_head {
  16         struct list_head *next, *prev;
  17 };
  18
  19 #define LIST_HEAD_INIT(name) { &(name), &(name) }
  20
  21 #define LIST_HEAD(name) \
  22         struct list_head name = { &name, &name }
  23
  24 #define INIT_LIST_HEAD(ptr) do { \
  25         (ptr)->next = (ptr); (ptr)->prev = (ptr); \
  26 } while (0)
  27
  28 #if (!defined(__GNUC__) && !defined(__WATCOMC__))
  29 #define __inline__
  30 #endif
  31
  32 /*
  33  * Insert a new entry between two known consecutive entries.
  34  *
  35  * This is only for internal list manipulation where we know
  36  * the prev/next entries already!
  37  */
  38 static __inline__ void __list_add(struct list_head * new,
  39         struct list_head * prev,
  40         struct list_head * next)
  41 {
  42         next->prev = new;
  43         new->next = next;
  44         new->prev = prev;
  45         prev->next = new;
  46 }
  47
  48 /*
  49  * Insert a new entry after the specified head..
  50  */
  51 static __inline__ void list_add(struct list_head *new, struct list_head *head)
  52 {
  53         __list_add(new, head, head->next);
  54 }
  55
  56 /*
  57  * Insert a new entry at the tail
  58  */
  59 static __inline__ void list_add_tail(struct list_head *new, struct list_head *head)
  60 {
  61         __list_add(new, head->prev, head);
  62 }
  63
  64 /*
  65  * Delete a list entry by making the prev/next entries
  66  * point to each other.
  67  *
  68  * This is only for internal list manipulation where we know
  69  * the prev/next entries already!
  70  */
  71 static __inline__ void __list_del(struct list_head * prev,
  72                                   struct list_head * next)
  73 {
  74         next->prev = prev;
  75         prev->next = next;
  76 }
  77
  78 static __inline__ void list_del(struct list_head *entry)
  79 {
  80         __list_del(entry->prev, entry->next);
  81 }
  82
  83 static __inline__ int list_empty(struct list_head *head)
  84 {
  85         return head->next == head;
  86 }
  87
  88 /*
  89  * Splice in "list" into "head"
  90  */
  91 static __inline__ void list_splice(struct list_head *list, struct list_head *head)
  92 {
  93         struct list_head *first = list->next;
  94
  95         if (first != list) {
  96                 struct list_head *last = list->prev;
  97                 struct list_head *at = head->next;
  98
  99                 first->prev = head;
 100                 head->next = first;
 101
 102                 last->next = at;
 103                 at->prev = last;
 104         }
 105 }
 106
 107 #define list_entry(ptr, type, member) \
 108         ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
 109
 110 #define list_for_each(pos, head) \
 111         for (pos = (head)->next; pos != (head); pos = pos->next)
 112
 113 #endif