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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2022-08-02 10:06:12 -0700 | 
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| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2022-08-02 10:06:12 -0700 | 
| commit | 8bb5e7f4dcd9b9ef22a3ea25c9066a8a968f12dd (patch) | |
| tree | 0f1383880607a227142f9388a066959926233ff1 /scripts/mod/list.h | |
| parent | 2a96271fb66c499e4a89d76a89d3d01170c10bef (diff) | |
| parent | 7c744d00990ea999d27f306f6db5ccb61b1304b2 (diff) | |
Merge branch 'next' into for-linus
Prepare input updates for 5.20 (or 6.0) merge window.
Diffstat (limited to 'scripts/mod/list.h')
| -rw-r--r-- | scripts/mod/list.h | 213 | 
1 files changed, 213 insertions, 0 deletions
diff --git a/scripts/mod/list.h b/scripts/mod/list.h new file mode 100644 index 000000000000..a924a6c4aa4d --- /dev/null +++ b/scripts/mod/list.h @@ -0,0 +1,213 @@ +/* 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 */  | 
