LXR linux/scripts/kconfig/list.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef LIST_H
   3#define LIST_H
   4
   5/*
   6 * Copied from include/linux/...
   7 */
   8
   9#undef offsetof
  10#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
  11
  12/**
  13 * container_of - cast a member of a structure out to the containing structure
  14 * @ptr:        the pointer to the member.
  15 * @type:       the type of the container struct this is embedded in.
  16 * @member:     the name of the member within the struct.
  17 *
  18 */
  19#define container_of(ptr, type, member) ({                      \
  20        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
  21        (type *)( (char *)__mptr - offsetof(type,member) );})
  22
  23
  24struct list_head {
  25        struct list_head *next, *prev;
  26};
  27
  28
  29#define LIST_HEAD_INIT(name) { &(name), &(name) }
  30
  31#define LIST_HEAD(name) \
  32        struct list_head name = LIST_HEAD_INIT(name)
  33
  34/**
  35 * list_entry - get the struct for this entry
  36 * @ptr:        the &struct list_head pointer.
  37 * @type:       the type of the struct this is embedded in.
  38 * @member:     the name of the list_head within the struct.
  39 */
  40#define list_entry(ptr, type, member) \
  41        container_of(ptr, type, member)
  42
  43/**
  44 * list_for_each_entry  -       iterate over list of given type
  45 * @pos:        the type * to use as a loop cursor.
  46 * @head:       the head for your list.
  47 * @member:     the name of the list_head within the struct.
  48 */
  49#define list_for_each_entry(pos, head, member)                          \
  50        for (pos = list_entry((head)->next, typeof(*pos), member);      \
  51             &pos->member != (head);    \
  52             pos = list_entry(pos->member.next, typeof(*pos), member))
  53
  54/**
  55 * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
  56 * @pos:        the type * to use as a loop cursor.
  57 * @n:          another type * to use as temporary storage
  58 * @head:       the head for your list.
  59 * @member:     the name of the list_head within the struct.
  60 */
  61#define list_for_each_entry_safe(pos, n, head, member)                  \
  62        for (pos = list_entry((head)->next, typeof(*pos), member),      \
  63                n = list_entry(pos->member.next, typeof(*pos), member); \
  64             &pos->member != (head);                                    \
  65             pos = n, n = list_entry(n->member.next, typeof(*n), member))
  66
  67/**
  68 * list_empty - tests whether a list is empty
  69 * @head: the list to test.
  70 */
  71static inline int list_empty(const struct list_head *head)
  72{
  73        return head->next == head;
  74}
  75
  76/*
  77 * Insert a new entry between two known consecutive entries.
  78 *
  79 * This is only for internal list manipulation where we know
  80 * the prev/next entries already!
  81 */
  82static inline void __list_add(struct list_head *_new,
  83                              struct list_head *prev,
  84                              struct list_head *next)
  85{
  86        next->prev = _new;
  87        _new->next = next;
  88        _new->prev = prev;
  89        prev->next = _new;
  90}
  91
  92/**
  93 * list_add_tail - add a new entry
  94 * @new: new entry to be added
  95 * @head: list head to add it before
  96 *
  97 * Insert a new entry before the specified head.
  98 * This is useful for implementing queues.
  99 */
 100static inline void list_add_tail(struct list_head *_new, struct list_head *head)
 101{
 102        __list_add(_new, head->prev, head);
 103}
 104
 105/*
 106 * Delete a list entry by making the prev/next entries
 107 * point to each other.
 108 *
 109 * This is only for internal list manipulation where we know
 110 * the prev/next entries already!
 111 */
 112static inline void __list_del(struct list_head *prev, struct list_head *next)
 113{
 114        next->prev = prev;
 115        prev->next = next;
 116}
 117
 118#define LIST_POISON1  ((void *) 0x00100100)
 119#define LIST_POISON2  ((void *) 0x00200200)
 120/**
 121 * list_del - deletes entry from list.
 122 * @entry: the element to delete from the list.
 123 * Note: list_empty() on entry does not return true after this, the entry is
 124 * in an undefined state.
 125 */
 126static inline void list_del(struct list_head *entry)
 127{
 128        __list_del(entry->prev, entry->next);
 129        entry->next = (struct list_head*)LIST_POISON1;
 130        entry->prev = (struct list_head*)LIST_POISON2;
 131}
 132#endif
 133