diff options
Diffstat (limited to 'include/linux/list.h')
| -rw-r--r-- | include/linux/list.h | 104 |
1 files changed, 59 insertions, 45 deletions
diff --git a/include/linux/list.h b/include/linux/list.h index 0f9d939b05f..3dc38279716 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -4,11 +4,6 @@ #include <linux/stddef.h> #include <linux/poison.h> -#ifndef ARCH_HAS_PREFETCH -#define ARCH_HAS_PREFETCH -static inline void prefetch(const void *x) {;} -#endif - /* * Simple doubly linked list implementation. * @@ -170,6 +165,16 @@ static inline int list_is_last(const struct list_head *list, } /** + * 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. */ @@ -363,26 +368,28 @@ static inline void list_splice_tail_init(struct list_head *list, }) /** - * list_for_each - iterate over a list - * @pos: the &struct list_head to use as a loop cursor. - * @head: the head for your list. + * 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_for_each(pos, head) \ - for (pos = (head)->next; prefetch(pos->next), pos != (head); \ - pos = pos->next) +#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_for_each - iterate over a list + * list_for_each - iterate over a list * @pos: the &struct list_head to use as a loop cursor. * @head: the head for your list. - * - * This variant differs from list_for_each() in that it's the - * simplest possible list iteration code, no prefetching is done. - * Use this for code that knows the list to be very short (empty - * or 1 entry) most of the time. */ -#define __list_for_each(pos, head) \ - for (pos = (head)->next; pos != (head); pos = pos->next) +#define list_for_each(pos, head) \ + for (pos = (head)->next; !list_is_head(pos, (head)); pos = pos->next) /** * list_for_each_prev - iterate over a list backwards @@ -390,8 +397,7 @@ static inline void list_splice_tail_init(struct list_head *list, * @head: the head for your list. */ #define list_for_each_prev(pos, head) \ - for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \ - pos = pos->prev) + for (pos = (head)->prev; !list_is_head(pos, (head)); pos = pos->prev) /** * list_for_each_safe - iterate over a list safe against removal of list entry @@ -411,30 +417,39 @@ static inline void list_splice_tail_init(struct list_head *list, */ #define list_for_each_prev_safe(pos, n, head) \ for (pos = (head)->prev, n = pos->prev; \ - prefetch(pos->prev), pos != (head); \ + !list_is_head(pos, (head)); \ pos = n, n = pos->prev) /** + * 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) \ + list_is_head(&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_struct within the struct. + * @member: the name of the list_head within the struct. */ #define list_for_each_entry(pos, head, member) \ - for (pos = list_entry((head)->next, typeof(*pos), member); \ - prefetch(pos->member.next), &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), 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_struct within the struct. + * @member: the name of the list_head within the struct. */ #define list_for_each_entry_reverse(pos, head, member) \ - for (pos = list_entry((head)->prev, typeof(*pos), member); \ - prefetch(pos->member.prev), &pos->member != (head); \ - pos = list_entry(pos->member.prev, typeof(*pos), member)) + for (pos = list_last_entry(head, typeof(*pos), member); \ + !list_entry_is_head(pos, head, member); \ + pos = list_prev_entry(pos, member)) /** * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue() @@ -451,41 +466,41 @@ static inline void list_splice_tail_init(struct list_head *list, * list_for_each_entry_continue - continue iteration 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_struct within the struct. + * @member: the name of the list_head within the struct. * * Continue to iterate over list of given type, continuing after * the current position. */ -#define list_for_each_entry_continue(pos, head, member) \ - for (pos = list_entry(pos->member.next, typeof(*pos), member); \ - prefetch(pos->member.next), &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), member)) +#define list_for_each_entry_continue(pos, head, member) \ + for (pos = list_next_entry(pos, member); \ + !list_entry_is_head(pos, head, member); \ + pos = list_next_entry(pos, member)) /** * list_for_each_entry_continue_reverse - iterate backwards from the given point * @pos: the type * to use as a loop cursor. * @head: the head for your list. - * @member: the name of the list_struct within the struct. + * @member: the name of the list_head within the struct. * * Start to iterate over list of given type backwards, continuing after * the current position. */ #define list_for_each_entry_continue_reverse(pos, head, member) \ - for (pos = list_entry(pos->member.prev, typeof(*pos), member); \ - prefetch(pos->member.prev), &pos->member != (head); \ - pos = list_entry(pos->member.prev, typeof(*pos), member)) + for (pos = list_prev_entry(pos, member); \ + !list_entry_is_head(pos, head, member); \ + pos = list_prev_entry(pos, member)) /** * list_for_each_entry_from - iterate over list of given type from the current point * @pos: the type * to use as a loop cursor. * @head: the head for your list. - * @member: the name of the list_struct within the struct. + * @member: the name of the list_head within the struct. * * Iterate over list of given type, continuing from current position. */ -#define list_for_each_entry_from(pos, head, member) \ - for (; prefetch(pos->member.next), &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), member)) +#define list_for_each_entry_from(pos, head, member) \ + for (; !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 @@ -654,8 +669,7 @@ static inline void hlist_add_after(struct hlist_node *n, #define hlist_entry(ptr, type, member) container_of(ptr,type,member) #define hlist_for_each(pos, head) \ - for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \ - pos = pos->next) + for (pos = (head)->first; pos ; pos = pos->next) #define hlist_for_each_safe(pos, n, head) \ for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \ |