#ifndef _LINUX_LLIST_H
#define _LINUX_LLIST_H
#include <stddef.h>
#ifndef inline
#define inline __inline__
#endif
static inline void prefetch(__attribute__((unused)) const void *x) {;}
/**
* container_of - cast a member of a structure out to the containing structure
*
* @ptr: the pointer to the member.
* @type: the type of the container struct this is embedded in.
* @member: the name of the member within the struct.
*
*/
#define container_of(ptr, type, member) ({ \
const typeof( ((type *)0)->member ) *__mptr = (typeof( ((type *)0)->member ) *)(ptr); \
(type *)( (char *)__mptr - offsetof(type, member) );})
/*
* These are non-NULL pointers that will result in page faults
* under normal circumstances, used to verify that nobody uses
* non-initialized llist entries.
*/
#define LLIST_POISON1 ((void *) 0x00100100)
#define LLIST_POISON2 ((void *) 0x00200200)
/*
* Simple doubly linked llist implementation.
*
* Some of the internal functions ("__xxx") are useful when
* manipulating whole llists 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 llist_head {
struct llist_head *next, *prev;
};
#define LLIST_HEAD_INIT(name) { &(name), &(name) }
#define LLIST_HEAD(name) \
struct llist_head name = LLIST_HEAD_INIT(name)
#define INIT_LLIST_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 llist manipulation where we know
* the prev/next entries already!
*/
static inline void __llist_add(struct llist_head *_new,
struct llist_head *prev,
struct llist_head *next)
{
next->prev = _new;
_new->next = next;
_new->prev = prev;
prev->next = _new;
}
/**
* llist_add - add a new entry
* @new: new entry to be added
* @head: llist head to add it after
*
* Insert a new entry after the specified head.
* This is good for implementing stacks.
*/
static inline void llist_add(struct llist_head *_new, struct llist_head *head)
{
__llist_add(_new, head, head->next);
}
/**
* llist_add_tail - add a new entry
* @new: new entry to be added
* @head: llist head to add it before
*
* Insert a new entry before the specified head.
* This is useful for implementing queues.
*/
static inline void llist_add_tail(struct llist_head *_new, struct llist_head *head)
{
__llist_add(_new, head->prev, head);
}
/*
* Delete a llist entry by making the prev/next entries
* point to each other.
*
* This is only for internal llist manipulation where we know
* the prev/next entries already!
*/
static inline void __llist_del(struct llist_head * prev, struct llist_head * next)
{
next->prev = prev;
prev->next = next;
}
/**
* llist_del - deletes entry from llist.
* @entry: the element to delete from the llist.
* Note: llist_empty on entry does not return true after this, the entry is
* in an undefined state.
*/
static inline void llist_del(struct llist_head *entry)
{
__llist_del(entry->prev, entry->next);
entry->next = (struct llist_head *)LLIST_POISON1;
entry->prev = (struct llist_head *)LLIST_POISON2;
}
/**
* llist_del_init - deletes entry from llist and reinitialize it.
* @entry: the element to delete from the llist.
*/
static inline void llist_del_init(struct llist_head *entry)
{
__llist_del(entry->prev, entry->next);
INIT_LLIST_HEAD(entry);
}
/**
* llist_move - delete from one llist and add as another's head
* @llist: the entry to move
* @head: the head that will precede our entry
*/
static inline void llist_move(struct llist_head *llist, struct llist_head *head)
{
__llist_del(llist->prev, llist->next);
llist_add(llist, head);
}
/**
* llist_move_tail - delete from one llist and add as another's tail
* @llist: the entry to move
* @head: the head that will follow our entry
*/
static inline void llist_move_tail(struct llist_head *llist,
struct llist_head *head)
{
__llist_del(llist->prev, llist->next);
llist_add_tail(llist, head);
}
/**
* llist_empty - tests whether a llist is empty
* @head: the llist to test.
*/
static inline int llist_empty(const struct llist_head *head)
{
return head->next == head;
}
static inline void __llist_splice(struct llist_head *llist,
struct llist_head *head)
{
struct llist_head *first = llist->next;
struct llist_head *last = llist->prev;
struct llist_head *at = head->next;
first->prev = head;
head->next = first;
last->next = at;
at->prev = last;
}
/**
* llist_splice - join two llists
* @llist: the new llist to add.
* @head: the place to add it in the first llist.
*/
static inline void llist_splice(struct llist_head *llist, struct llist_head *head)
{
if (!llist_empty(llist))
__llist_splice(llist, head);
}
/**
* llist_splice_init - join two llists and reinitialise the emptied llist.
* @llist: the new llist to add.
* @head: the place to add it in the first llist.
*
* The llist at @llist is reinitialised
*/
static inline void llist_splice_init(struct llist_head *llist,
struct llist_head *head)
{
if (!llist_empty(llist)) {
__llist_splice(llist, head);
INIT_LLIST_HEAD(llist);
}
}
/**
* llist_entry - get the struct for this entry
* @ptr: the &struct llist_head pointer.
* @type: the type of the struct this is embedded in.
* @member: the name of the llist_struct within the struct.
*/
#define llist_entry(ptr, type, member) \
container_of(ptr, type, member)
/**
* llist_for_each - iterate over a llist
* @pos: the &struct llist_head to use as a loop counter.
* @head: the head for your llist.
*/
#define llist_for_each(pos, head) \
for (pos = (head)->next, prefetch(pos->next); pos != (head); \
pos = pos->next, prefetch(pos->next))
/**
* __llist_for_each - iterate over a llist
* @pos: the &struct llist_head to use as a loop counter.
* @head: the head for your llist.
*
* This variant differs from llist_for_each() in that it's the
* simplest possible llist iteration code, no prefetching is done.
* Use this for code that knows the llist to be very short (empty
* or 1 entry) most of the time.
*/
#define __llist_for_each(pos, head) \
for (pos = (head)->next; pos != (head); pos = pos->next)
/**
* llist_for_each_prev - iterate over a llist backwards
* @pos: the &struct llist_head to use as a loop counter.
* @head: the head for your llist.
*/
#define llist_for_each_prev(pos, head) \
for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
pos = pos->prev, prefetch(pos->prev))
/**
* llist_for_each_safe - iterate over a llist safe against removal of llist entry
* @pos: the &struct llist_head to use as a loop counter.
* @n: another &struct llist_head to use as temporary storage
* @head: the head for your llist.
*/
#define llist_for_each_safe(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head); \
pos = n, n = pos->next)
/**
* llist_for_each_entry - iterate over llist of given type
* @pos: the type * to use as a loop counter.
* @head: the head for your llist.
* @member: the name of the llist_struct within the struct.
*/
#define llist_for_each_entry(pos, head, member) \
for (pos = llist_entry((head)->next, typeof(*pos), member), \
prefetch(pos->member.next); \
&pos->member != (head); \
pos = llist_entry(pos->member.next, typeof(*pos), member), \
prefetch(pos->member.next))
/**
* llist_for_each_entry_reverse - iterate backwards over llist of given type.
* @pos: the type * to use as a loop counter.
* @head: the head for your llist.
* @member: the name of the llist_struct within the struct.
*/
#define llist_for_each_entry_reverse(pos, head, member) \
for (pos = llist_entry((head)->prev, typeof(*pos), member), \
prefetch(pos->member.prev); \
&pos->member != (head); \
pos = llist_entry(pos->member.prev, typeof(*pos), member), \
prefetch(pos->member.prev))
/**
* llist_for_each_entry_continue - iterate over llist of given type
* continuing after existing point
* @pos: the type * to use as a loop counter.
* @head: the head for your llist.
* @member: the name of the llist_struct within the struct.
*/
#define llist_for_each_entry_continue(pos, head, member) \
for (pos = llist_entry(pos->member.next, typeof(*pos), member), \
prefetch(pos->member.next); \
&pos->member != (head); \
pos = llist_entry(pos->member.next, typeof(*pos), member), \
prefetch(pos->member.next))
/**
* llist_for_each_entry_safe - iterate over llist of given type safe against removal of llist entry
* @pos: the type * to use as a loop counter.
* @n: another type * to use as temporary storage
* @head: the head for your llist.
* @member: the name of the llist_struct within the struct.
*/
#define llist_for_each_entry_safe(pos, n, head, member) \
for (pos = llist_entry((head)->next, typeof(*pos), member), \
n = llist_entry(pos->member.next, typeof(*pos), member); \
&pos->member != (head); \
pos = n, n = llist_entry(n->member.next, typeof(*n), member))
/**
* llist_for_each_rcu - iterate over an rcu-protected llist
* @pos: the &struct llist_head to use as a loop counter.
* @head: the head for your llist.
*/
#define llist_for_each_rcu(pos, head) \
for (pos = (head)->next, prefetch(pos->next); pos != (head); \
pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next))
#define __llist_for_each_rcu(pos, head) \
for (pos = (head)->next; pos != (head); \
pos = pos->next, ({ smp_read_barrier_depends(); 0;}))
/**
* llist_for_each_safe_rcu - iterate over an rcu-protected llist safe
* against removal of llist entry
* @pos: the &struct llist_head to use as a loop counter.
* @n: another &struct llist_head to use as temporary storage
* @head: the head for your llist.
*/
#define llist_for_each_safe_rcu(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head); \
pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next)
/**
* llist_for_each_entry_rcu - iterate over rcu llist of given type
* @pos: the type * to use as a loop counter.
* @head: the head for your llist.
* @member: the name of the llist_struct within the struct.
*/
#define llist_for_each_entry_rcu(pos, head, member) \
for (pos = llist_entry((head)->next, typeof(*pos), member), \
prefetch(pos->member.next); \
&pos->member != (head); \
pos = llist_entry(pos->member.next, typeof(*pos), member), \
({ smp_read_barrier_depends(); 0;}), \
prefetch(pos->member.next))
/**
* llist_for_each_continue_rcu - iterate over an rcu-protected llist
* continuing after existing point.
* @pos: the &struct llist_head to use as a loop counter.
* @head: the head for your llist.
*/
#define llist_for_each_continue_rcu(pos, head) \
for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
(pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next))
#endif
