list.h

   1 /**
   2  * Copied from linux kernel 3.1.0 include/linux/list.h and include/linux/types.h
   3  * with some modifications and unused code removed
   4  * License is GPLv2 only
   5  */
   6
   7 struct list_head {
   8         struct list_head *next, *prev;
   9 };
  10
  11 static inline void init_list_head(struct list_head *list)
  12 {
  13         list->next = list;
  14         list->prev = list;
  15 }
  16
  17 /*
  18  * Insert a new entry between two known consecutive entries.
  19  *
  20  * This is only for internal list manipulation where we know
  21  * the prev/next entries already!
  22  */
  23 static inline void __list_add(struct list_head *new,
  24                               struct list_head *prev,
  25                               struct list_head *next)
  26 {
  27         next->prev = new;
  28         new->next = next;
  29         new->prev = prev;
  30         prev->next = new;
  31 }
  32
  33 /**
  34  * list_add - add a new entry
  35  * @new: new entry to be added
  36  * @head: list head to add it after
  37  *
  38  * Insert a new entry after the specified head.
  39  * This is good for implementing stacks.
  40  */
  41 static inline void list_add(struct list_head *new, struct list_head *head)
  42 {
  43         __list_add(new, head, head->next);
  44 }
  45
  46
  47 /**
  48  * list_add_tail - add a new entry
  49  * @new: new entry to be added
  50  * @head: list head to add it before
  51  *
  52  * Insert a new entry before the specified head.
  53  * This is useful for implementing queues.
  54  */
  55 static inline void list_add_tail(struct list_head *new, struct list_head *head)
  56 {
  57         __list_add(new, head->prev, head);
  58 }
  59
  60 /*
  61  * Delete a list entry by making the prev/next entries
  62  * point to each other.
  63  *
  64  * This is only for internal list manipulation where we know
  65  * the prev/next entries already!
  66  */
  67 static inline void __list_del(struct list_head * prev, struct list_head * next)
  68 {
  69         next->prev = prev;
  70         prev->next = next;
  71 }
  72
  73 static inline void list_del(struct list_head *entry)
  74 {
  75         __list_del(entry->prev, entry->next);
  76         entry->next = 0;
  77         entry->prev = 0;
  78 }
  79
  80 /**
  81  * list_empty - tests whether a list is empty
  82  * @head: the list to test.
  83  */
  84 static inline int list_empty(const struct list_head *head)
  85 {
  86         return head->next == head;
  87 }