/* SPDX-License-Identifier: GPL-2.0 */#ifndef LIST_H#define LIST_H #include <stddef.h> #include "list_types.h" /* Are two types/vars the same type (ignoring qualifiers)? */#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) /** * 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) ({				\	void *__mptr = (void *)(ptr);					\	_Static_assert(__same_type(*(ptr), ((type *)0)->member) ||	\		      __same_type(*(ptr), void),			\		      "pointer type mismatch in container_of()");	\	((type *)(__mptr - offsetof(type, member))); }) #define LIST_POISON1  ((void *) 0x100)#define LIST_POISON2  ((void *) 0x122) /* * Circular 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. */ #define LIST_HEAD_INIT(name) { &(name), &(name) } #define LIST_HEAD(name) \	struct list_head name = LIST_HEAD_INIT(name) /** * INIT_LIST_HEAD - Initialize a list_head structure * @list: list_head structure to be initialized. * * Initializes the list_head to point to itself.  If it is a list header, * the result is an empty list. */static inline void INIT_LIST_HEAD(struct list_head *list){	list->next = list;	list->prev = list;} /* * 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 *new,			      struct list_head *prev,			      struct list_head *next){	next->prev = new;	new->next = next;	new->prev = prev;	prev->next = new;} /** * 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 *new, struct list_head *head){	__list_add(new, head, head->next);} /** * list_add_tail - add a new entry * @new: 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 *new, struct list_head *head){	__list_add(new, 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;} static inline void __list_del_entry(struct list_head *entry){	__list_del(entry->prev, entry->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(entry);	entry->next = LIST_POISON1;	entry->prev = LIST_POISON2;} /** * 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_replace_init - replace old entry by new one and initialize the old 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_init(struct list_head *old,				     struct list_head *new){	list_replace(old, new);	INIT_LIST_HEAD(old);} /** * list_move - delete from one list and add as another's head * @list: the entry to move * @head: the head that will precede our entry */static inline void list_move(struct list_head *list, struct list_head *head){	__list_del_entry(list);	list_add(list, head);} /** * list_move_tail - delete from one list and add as another's tail * @list: the entry to move * @head: the head that will follow our entry */static inline void list_move_tail(struct list_head *list,				  struct list_head *head){	__list_del_entry(list);	list_add_tail(list, head);} /** * list_is_first -- tests whether @list is the first entry in list @head * @list: the entry to test * @head: the head of the list */static inline int list_is_first(const struct list_head *list, const struct list_head *head){	return list->prev == 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;} /** * list_is_head - tests whether @list is the list @head * @list: the entry to test * @head: the head of the list */static inline int list_is_head(const struct list_head *list, const struct list_head *head){	return list == head;} /** * list_empty - tests whether a list is empty * @head: the list to test. */static inline int list_empty(const struct list_head *head){	return head->next == head;} /** * 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_head within the struct. */#define list_entry(ptr, type, member) \	container_of(ptr, type, member) /** * list_first_entry - get the first 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_first_entry(ptr, type, member) \	list_entry((ptr)->next, type, member) /** * 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_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_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_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)) /** * list_for_each_entry - iterate 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(pos, head, member)				\	for (pos = list_first_entry(head, typeof(*pos), member);	\	     !list_entry_is_head(pos, head, member);			\	     pos = list_next_entry(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);		\	     !list_entry_is_head(pos, head, member); 			\	     pos = list_prev_entry(pos, member)) /** * list_for_each_entry_safe - iterate over list of given type. Safe against removal of list entry * @pos:	the type * to use as a loop cursor. * @n:		another type * to use as temporary storage * @head:	the head for your list. * @member:	the name of the list_head within the struct. */#define list_for_each_entry_safe(pos, n, head, member)			\	for (pos = list_first_entry(head, typeof(*pos), member),	\		n = list_next_entry(pos, member);			\	     !list_entry_is_head(pos, head, member);			\	     pos = n, n = list_next_entry(n, member)) /* * 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). */ #define HLIST_HEAD_INIT { .first = NULL }#define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)static inline void INIT_HLIST_NODE(struct hlist_node *h){	h->next = NULL;	h->pprev = NULL;} /** * hlist_unhashed - Has node been removed from list and reinitialized? * @h: Node to be checked * * Not that not all removal functions will leave a node in unhashed * state.  For example, hlist_nulls_del_init_rcu() does leave the * node in unhashed state, but hlist_nulls_del() does not. */static inline int hlist_unhashed(const struct hlist_node *h){	return !h->pprev;} 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;} /** * hlist_del - Delete the specified hlist_node from its list * @n: Node to delete. * * Note that this function leaves the node in hashed state.  Use * hlist_del_init() or similar instead to unhash @n. */static inline void hlist_del(struct hlist_node *n){	__hlist_del(n);	n->next = LIST_POISON1;	n->pprev = LIST_POISON2;} /** * hlist_del_init - Delete the specified hlist_node from its list and initialize * @n: Node to delete. * * Note that this function leaves the node in unhashed state. */static inline void hlist_del_init(struct hlist_node *n){	if (!hlist_unhashed(n)) {		__hlist_del(n);		INIT_HLIST_NODE(n);	}} /** * hlist_add_head - add a new entry at the beginning of the hlist * @n: new entry to be added * @h: hlist head to add it after * * Insert a new entry after the specified head. * This is good for implementing stacks. */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;} #define hlist_entry(ptr, type, member) container_of(ptr, type, member) #define hlist_entry_safe(ptr, type, member) \	({ typeof(ptr) ____ptr = (ptr); \	   ____ptr ? hlist_entry(____ptr, type, member) : NULL; \	}) /** * hlist_for_each_entry	- iterate 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 hlist_node within the struct. */#define hlist_for_each_entry(pos, head, member)				\	for (pos = hlist_entry_safe((head)->first, typeof(*(pos)), member);\	     pos;							\	     pos = hlist_entry_safe((pos)->member.next, typeof(*(pos)), member)) /** * hlist_for_each_entry_safe - iterate over list of given type safe against removal of list entry * @pos:	the type * to use as a loop cursor. * @n:		a &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(pos, n, head, member) 		\	for (pos = hlist_entry_safe((head)->first, typeof(*pos), member);\	     pos && ({ n = pos->member.next; 1; });			\	     pos = hlist_entry_safe(n, typeof(*pos), member)) #endif /* LIST_H */