diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/list.h | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/include/list.h b/include/list.h new file mode 100644 index 0000000..d26c9d1 --- /dev/null +++ b/include/list.h @@ -0,0 +1,263 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2006 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#ifndef __LIST_H__ +#define __LIST_H__ + +#include <stddef.h> + +/* + * This undef is here because BSD 4.4 added some LIST_ macros into system + * header file sys/queue.h. This header is included in many other system + * headers and thus causes "macro redefined" warnings. + * + * As OS X is kind of a derivate of BSD, this affects OS X too. + * + * To use our own LIST_ macros (copied from kernel code), we have to + * at first undefine the conflicting system macros. + * + */ +#undef LIST_HEAD +#undef LIST_HEAD_INIT + +/* + * Simple, generic doubly-linked list implementation. + */ + +struct list_head { + struct list_head *next; + struct list_head *prev; +}; + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +#define INIT_LIST_HEAD(list) list_head_init(list) +static inline void list_head_init(struct list_head *list) +{ + list->next = list->prev = list; +} + +static inline void list_head_destroy(struct list_head *list) +{ + list->next = list->prev = NULL; +} + +static inline void __list_add(struct list_head *add, + struct list_head *prev, struct list_head *next) +{ + next->prev = add; + add->next = next; + add->prev = prev; + prev->next = add; +} + +static inline void list_add(struct list_head *add, struct list_head *head) +{ + __list_add(add, head, head->next); +} + +static inline void list_add_tail(struct list_head *add, struct list_head *head) +{ + __list_add(add, head->prev, head); +} + +static inline void __list_del(struct list_head *prev, struct list_head *next) +{ + next->prev = prev; + prev->next = next; +} + +static inline void list_del_init(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + list_head_init(entry); +} + +static inline void list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); +} + +static inline void list_move(struct list_head *list, struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add(list, head); +} + +static inline void list_move_tail(struct list_head *list, struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add_tail(list, head); +} + +/** + * list_is_last - tests whether @list is the last entry in list @head + * @list: the entry to test + * @head: the head of the list + */ +static inline int list_is_last(const struct list_head *list, const struct list_head *head) +{ + return list->next == head; +} + +static inline int list_empty(const struct list_head *head) +{ + return head->next == head; +} + +static inline void __list_splice(struct list_head *list, + struct list_head *prev, + struct list_head *next) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + + first->prev = prev; + prev->next = first; + + last->next = next; + next->prev = last; +} + +static inline void list_splice(struct list_head *list, struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head, head->next); +} + +static inline void list_splice_tail(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head->prev, head); +} + +static inline void list_splice_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head, head->next); + list_head_init(list); + } +} + +#define list_entry(ptr, type, member) ({ \ + const typeof( ((type *)0)->member ) *__mptr = (ptr); \ + (type *)( (char *)__mptr - offsetof(type,member) );}) + +#define list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); pos = pos->next) + +#define list_for_each_safe(pos, n, head) \ + for (pos = (head)->next, n = pos->next; pos != (head); \ + pos = n, n = pos->next) + +#define list_for_each_entry(pos, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) + +#define list_for_each_entry_safe(pos, n, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member), \ + n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + +#define list_first_entry(ptr, type, member) \ + list_entry((ptr)->next, type, member) + +#define container_of(ptr, type, member) ({ \ + const typeof( ((type *)0)->member ) *__mptr = (ptr); \ + (type *)( (char *)__mptr - offsetof(type,member) );}) + +/** + * list_entry_is_head - test if the entry points to the head of the list + * @pos: the type * to cursor + * @head: the head for your list. + * @member: the name of the list_head within the struct. + */ +#define list_entry_is_head(pos, head, member) \ + (&pos->member == (head)) + +typedef int __attribute__((nonnull(2,3))) (*list_cmp_func_t)(void *, + const struct list_head *, const struct list_head *); +__attribute__((nonnull(2,3))) +void list_sort(void *priv, struct list_head *head, list_cmp_func_t cmp); + +/** + * list_splice_tail_init - join two lists and reinitialise the emptied list + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * Each of the lists is a queue. + * The list at @list is reinitialised + */ +static inline void list_splice_tail_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head->prev, head); + INIT_LIST_HEAD(list); + } +} + +/** + * list_replace - replace old entry by new one + * @old : the element to be replaced + * @new : the new element to insert + * + * If @old was empty, it will be overwritten. + */ +static inline void list_replace(struct list_head *old, + struct list_head *new) +{ + new->next = old->next; + new->next->prev = new; + new->prev = old->prev; + new->prev->next = new; +} + +/** + * list_last_entry - get the last element from a list + * @ptr: the list head to take the element from. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_head within the struct. + * + * Note, that list is expected to be not empty. + */ +#define list_last_entry(ptr, type, member) \ + list_entry((ptr)->prev, type, member) + +/** + * list_prev_entry - get the prev element in list + * @pos: the type * to cursor + * @member: the name of the list_head within the struct. + */ +#define list_prev_entry(pos, member) \ + list_entry((pos)->member.prev, typeof(*(pos)), member) + +/** + * list_next_entry - get the next element in list + * @pos: the type * to cursor + * @member: the name of the list_head within the struct. + */ +#define list_next_entry(pos, member) \ + list_entry((pos)->member.next, typeof(*(pos)), member) + +/** + * list_for_each_entry_reverse - iterate backwards over list of given type. + * @pos: the type * to use as a loop cursor. + * @head: the head for your list. + * @member: the name of the list_head within the struct. + */ +#define list_for_each_entry_reverse(pos, head, member) \ + for (pos = list_last_entry(head, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_prev_entry(pos, member)) + +#endif /* __LIST_H__ */ |