| #ifndef _LINUX_LIST_H |
| #define _LINUX_LIST_H |
| |
| /* |
| * Simple doubly linked list implementation. |
| * |
| * Some of the internal functions ("__xxx") are useful when |
| * manipulating whole lists rather than single entries, as |
| * sometimes we already know the next/prev entries and we can |
| * generate better code by using them directly rather than |
| * using the generic single-entry routines. |
| */ |
| |
| struct list_head { |
| struct list_head *next, *prev; |
| }; |
| |
| #define LIST_HEAD_INIT(name) { &(name), &(name) } |
| |
| #define LIST_HEAD(name) \ |
| struct list_head name = LIST_HEAD_INIT(name) |
| |
| #define INIT_LIST_HEAD(ptr) do { \ |
| (ptr)->next = (ptr); (ptr)->prev = (ptr); \ |
| } while (0) |
| |
| /* |
| * Insert a new entry between two known consecutive entries. |
| * |
| * This is only for internal list manipulation where we know |
| * the prev/next entries already! |
| */ |
| static __inline__ void __list_add(struct list_head * nnew, |
| struct list_head * prev, |
| struct list_head * next) |
| { |
| next->prev = nnew; |
| nnew->next = next; |
| nnew->prev = prev; |
| prev->next = nnew; |
| } |
| |
| /** |
| * list_add - add a new entry |
| * @new: new entry to be added |
| * @head: list head to add it after |
| * |
| * Insert a new entry after the specified head. |
| * This is good for implementing stacks. |
| */ |
| static __inline__ void list_add(struct list_head *nnew, struct list_head *head) |
| { |
| __list_add(nnew, head, head->next); |
| } |
| |
| /** |
| * list_add_tail - add a new entry |
| * @nnew: new entry to be added |
| * @head: list head to add it before |
| * |
| * Insert a new entry before the specified head. |
| * This is useful for implementing queues. |
| */ |
| static __inline__ void list_add_tail(struct list_head *nnew, struct list_head *head) |
| { |
| __list_add(nnew, head->prev, head); |
| } |
| |
| /* |
| * Delete a list entry by making the prev/next entries |
| * point to each other. |
| * |
| * This is only for internal list manipulation where we know |
| * the prev/next entries already! |
| */ |
| static __inline__ void __list_del(struct list_head * prev, |
| struct list_head * next) |
| { |
| next->prev = prev; |
| prev->next = next; |
| } |
| |
| /** |
| * list_del - deletes entry from list. |
| * @entry: the element to delete from the list. |
| * Note: list_empty on entry does not return true after this, the entry is in an undefined state. |
| */ |
| static __inline__ void list_del(struct list_head *entry) |
| { |
| __list_del(entry->prev, entry->next); |
| } |
| |
| /** |
| * list_del_init - deletes entry from list and reinitialize it. |
| * @entry: the element to delete from the list. |
| */ |
| static __inline__ void list_del_init(struct list_head *entry) |
| { |
| __list_del(entry->prev, entry->next); |
| INIT_LIST_HEAD(entry); |
| } |
| |
| /** |
| * list_empty - tests whether a list is empty |
| * @head: the list to test. |
| */ |
| static __inline__ int list_empty(struct list_head *head) |
| { |
| return head->next == head; |
| } |
| |
| /** |
| * list_splice - join two lists |
| * @list: the new list to add. |
| * @head: the place to add it in the first list. |
| */ |
| static __inline__ void list_splice(struct list_head *list, struct list_head *head) |
| { |
| struct list_head *first = list->next; |
| |
| if (first != list) { |
| struct list_head *last = list->prev; |
| struct list_head *at = head->next; |
| |
| first->prev = head; |
| head->next = first; |
| |
| last->next = at; |
| at->prev = last; |
| } |
| } |
| |
| /** |
| * list_entry - get the struct for this entry |
| * @ptr: the &struct list_head pointer. |
| * @type: the type of the struct this is embedded in. |
| * @member: the name of the list_struct within the struct. |
| */ |
| #define list_entry(ptr, type, member) \ |
| ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) |
| |
| /** |
| * list_for_each - iterate over a list |
| * @pos: the &struct list_head to use as a loop counter. |
| * @head: the head for your list. |
| */ |
| #define list_for_each(pos, head) \ |
| for (pos = (head)->next; pos != (head); \ |
| pos = pos->next) |
| |
| /** |
| * list_for_each_safe - iterate over a list safe against removal of list entry |
| * @pos: the &struct list_head to use as a loop counter. |
| * @n: another &struct list_head to use as temporary storage |
| * @head: the head for your list. |
| */ |
| #define list_for_each_safe(pos, n, head) \ |
| for (pos = (head)->next, n = pos->next; pos != (head); \ |
| pos = n, n = pos->next) |
| |
| /** |
| * list_for_each_prev - iterate over a list in reverse order |
| * @pos: the &struct list_head to use as a loop counter. |
| * @head: the head for your list. |
| */ |
| #define list_for_each_prev(pos, head) \ |
| for (pos = (head)->prev; pos != (head); \ |
| pos = pos->prev) |
| |
| |
| #endif |