blob: 95023c75aa1799732ea8f2ea99e64c3df4027644 [file] [log] [blame]
#ifndef _LINUX_FLIST_H
#define _LINUX_FLIST_H
#undef offsetof
#ifdef __compiler_offsetof
#define offsetof(TYPE,MEMBER) __compiler_offsetof(TYPE,MEMBER)
#else
#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
#endif
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (ptr); \
(type *)( (char *)__mptr - offsetof(type,member) );})
/*
* 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 flist_head {
struct flist_head *next, *prev;
};
#define FLIST_HEAD_INIT(name) { &(name), &(name) }
#define FLIST_HEAD(name) \
struct flist_head name = FLIST_HEAD_INIT(name)
#define INIT_FLIST_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 __flist_add(struct flist_head *new_entry,
struct flist_head *prev,
struct flist_head *next)
{
next->prev = new_entry;
new_entry->next = next;
new_entry->prev = prev;
prev->next = new_entry;
}
/**
* flist_add - add a new entry
* @new_entry: 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 flist_add(struct flist_head *new_entry,
struct flist_head *head)
{
__flist_add(new_entry, head, head->next);
}
static inline void flist_add_tail(struct flist_head *new_entry,
struct flist_head *head)
{
__flist_add(new_entry, 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 __flist_del(struct flist_head *prev,
struct flist_head * next)
{
next->prev = prev;
prev->next = next;
}
/**
* flist_del - deletes entry from list.
* @entry: the element to delete from the list.
* Note: flist_empty on entry does not return true after this, the entry is
* in an undefined state.
*/
static inline void flist_del(struct flist_head *entry)
{
__flist_del(entry->prev, entry->next);
entry->next = NULL;
entry->prev = NULL;
}
/**
* flist_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
*/
static inline void flist_del_init(struct flist_head *entry)
{
__flist_del(entry->prev, entry->next);
INIT_FLIST_HEAD(entry);
}
/**
* flist_empty - tests whether a list is empty
* @head: the list to test.
*/
static inline int flist_empty(const struct flist_head *head)
{
return head->next == head;
}
static inline void __flist_splice(const struct flist_head *list,
struct flist_head *prev,
struct flist_head *next)
{
struct flist_head *first = list->next;
struct flist_head *last = list->prev;
first->prev = prev;
prev->next = first;
last->next = next;
next->prev = last;
}
static inline void flist_splice(const struct flist_head *list,
struct flist_head *head)
{
if (!flist_empty(list))
__flist_splice(list, head, head->next);
}
static inline void flist_splice_init(struct flist_head *list,
struct flist_head *head)
{
if (!flist_empty(list)) {
__flist_splice(list, head, head->next);
INIT_FLIST_HEAD(list);
}
}
/**
* flist_entry - get the struct for this entry
* @ptr: the &struct flist_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the flist_struct within the struct.
*/
#define flist_entry(ptr, type, member) \
container_of(ptr, type, member)
/**
* flist_for_each - iterate over a list
* @pos: the &struct flist_head to use as a loop counter.
* @head: the head for your list.
*/
#define flist_for_each(pos, head) \
for (pos = (head)->next; pos != (head); pos = pos->next)
/**
* flist_for_each_safe - iterate over a list safe against removal of list entry
* @pos: the &struct flist_head to use as a loop counter.
* @n: another &struct flist_head to use as temporary storage
* @head: the head for your list.
*/
#define flist_for_each_safe(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head); \
pos = n, n = pos->next)
#endif