diff options
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 000000000..a924a6c4a --- /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 */ |