scripts/config/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
  24 struct 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  */
  71 static 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  */
  82 static 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  */
 100 static 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  */
 112 static 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  */
 126 static 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