/* SPDX-License-Identifier: GPL-2.0 */#ifndef LIST_H#define LIST_H #include <stdbool.h>#include <stddef.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. */ struct list_head {	struct list_head *next, *prev;}; #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_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_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_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_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)) #endif /* LIST_H */