5 #ifdef __compiler_offsetof
6 #define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
8 #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
11 #define container_of(ptr, type, member) ({ \
12 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
13 (type *)( (char *)__mptr - offsetof(type,member) );})
16 * Simple doubly linked list implementation.
18 * Some of the internal functions ("__xxx") are useful when
19 * manipulating whole lists rather than single entries, as
20 * sometimes we already know the next/prev entries and we can
21 * generate better code by using them directly rather than
22 * using the generic single-entry routines.
26 struct list_head *next, *prev;
29 #define LIST_HEAD_INIT(name) { &(name), &(name) }
31 #define LIST_HEAD(name) \
32 struct list_head name = LIST_HEAD_INIT(name)
34 #define INIT_LIST_HEAD(ptr) do { \
35 (ptr)->next = (ptr); (ptr)->prev = (ptr); \
39 * Insert a new entry between two known consecutive entries.
41 * This is only for internal list manipulation where we know
42 * the prev/next entries already!
44 static inline void __list_add(struct list_head *new,
45 struct list_head *prev,
46 struct list_head *next)
55 * list_add - add a new entry
56 * @new: new entry to be added
57 * @head: list head to add it after
59 * Insert a new entry after the specified head.
60 * This is good for implementing stacks.
62 static inline void list_add(struct list_head *new, struct list_head *head)
64 __list_add(new, head, head->next);
67 static inline void list_add_tail(struct list_head *new, struct list_head *head)
69 __list_add(new, head->prev, head);
73 * Delete a list entry by making the prev/next entries
74 * point to each other.
76 * This is only for internal list manipulation where we know
77 * the prev/next entries already!
79 static inline void __list_del(struct list_head * prev, struct list_head * next)
86 * list_del - deletes entry from list.
87 * @entry: the element to delete from the list.
88 * Note: list_empty on entry does not return true after this, the entry is
89 * in an undefined state.
91 static inline void list_del(struct list_head *entry)
93 __list_del(entry->prev, entry->next);
99 * list_empty - tests whether a list is empty
100 * @head: the list to test.
102 static inline int list_empty(const struct list_head *head)
104 return head->next == head;
108 * list_entry - get the struct for this entry
109 * @ptr: the &struct list_head pointer.
110 * @type: the type of the struct this is embedded in.
111 * @member: the name of the list_struct within the struct.
113 #define list_entry(ptr, type, member) \
114 container_of(ptr, type, member)
117 * list_for_each - iterate over a list
118 * @pos: the &struct list_head to use as a loop counter.
119 * @head: the head for your list.
121 #define list_for_each(pos, head) \
122 for (pos = (head)->next; pos != (head); pos = pos->next)
125 * list_for_each_safe - iterate over a list safe against removal of list entry
126 * @pos: the &struct list_head to use as a loop counter.
127 * @n: another &struct list_head to use as temporary storage
128 * @head: the head for your list.
130 #define list_for_each_safe(pos, n, head) \
131 for (pos = (head)->next, n = pos->next; pos != (head); \
132 pos = n, n = pos->next)