-/*
- * Double linked lists with a single pointer list head.
- * Mostly useful for hash tables where the two pointer list head is
- * too wasteful.
- * You lose the ability to access the tail in O(1).
- */
-
-struct hlist_head {
- struct hlist_node *first;
-};
-
-struct hlist_node {
- struct hlist_node *next, **pprev;
-};
-
-#define HLIST_HEAD_INIT { .first = NULL }
-#define HLIST_HEAD(name) struct hlist_head name = { .first = NULL }
-#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
-#define INIT_HLIST_NODE(ptr) ((ptr)->next = NULL, (ptr)->pprev = NULL)
-
-static __inline__ int hlist_unhashed(struct hlist_node *h)
-{
- return !h->pprev;
-}
-
-static __inline__ int hlist_empty(struct hlist_head *h)
-{
- return !h->first;
-}
-
-static __inline__ void __hlist_del(struct hlist_node *n)
-{
- struct hlist_node *next = n->next;
- struct hlist_node **pprev = n->pprev;
- *pprev = next;
- if (next)
- next->pprev = pprev;
-}
-
-static __inline__ void hlist_del(struct hlist_node *n)
-{
- __hlist_del(n);
- n->next = LIST_POISON1;
- n->pprev = LIST_POISON2;
-}
-
-static __inline__ void hlist_del_init(struct hlist_node *n)
-{
- if (n->pprev) {
- __hlist_del(n);
- INIT_HLIST_NODE(n);
- }
-}
-
-static __inline__ void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
-{
- struct hlist_node *first = h->first;
- n->next = first;
- if (first)
- first->pprev = &n->next;
- h->first = n;
- n->pprev = &h->first;
-}
-
-/* next must be != NULL */
-static __inline__ void hlist_add_before(struct hlist_node *n, struct hlist_node *next)
-{
- n->pprev = next->pprev;
- n->next = next;
- next->pprev = &n->next;
- *(n->pprev) = n;
-}
-
-static __inline__ void hlist_add_after(struct hlist_node *n,
- struct hlist_node *next)
-{
- next->next = n->next;
- *(next->pprev) = n;
- n->next = next;
-}
-
-#define hlist_entry(ptr, type, member) container_of(ptr,type,member)
-
-/* Cannot easily do prefetch unfortunately */
-#define hlist_for_each(pos, head) \
- for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
- pos = pos->next)
-
-#define hlist_for_each_safe(pos, n, head) \
- for (pos = (head)->first; n = pos ? pos->next : 0, pos; \
- pos = n)
-
-/**
- * hlist_for_each_entry - iterate over list of given type
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
- * @head: the head for your list.
- * @member: the name of the hlist_node within the struct.
- */
-#define hlist_for_each_entry(tpos, pos, head, member) \
- for (pos = (head)->first; \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
-
-/**
- * hlist_for_each_entry_continue - iterate over a hlist continuing after existing point
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
- * @member: the name of the hlist_node within the struct.
- */
-#define hlist_for_each_entry_continue(tpos, pos, member) \
- for (pos = (pos)->next; \
- pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
-
-/**
- * hlist_for_each_entry_from - iterate over a hlist continuing from existing point
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
- * @member: the name of the hlist_node within the struct.
- */
-#define hlist_for_each_entry_from(tpos, pos, member) \
- for (; pos && ({ prefetch(pos->next); 1;}) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next)
-
-/**
- * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry
- * @tpos: the type * to use as a loop counter.
- * @pos: the &struct hlist_node to use as a loop counter.
- * @n: another &struct hlist_node to use as temporary storage
- * @head: the head for your list.
- * @member: the name of the hlist_node within the struct.
- */
-#define hlist_for_each_entry_safe(tpos, pos, n, head, member) \
- for (pos = (head)->first; \
- pos && ({ n = pos->next; 1; }) && \
- ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = n)
-
-#endif