From 008208c6b26f21c2648c250a09c55e737c02c5f8 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 12 Nov 2013 15:10:01 -0800 Subject: list: introduce list_next_entry() and list_prev_entry() Add two trivial helpers list_next_entry() and list_prev_entry(), they can have a lot of users including list.h itself. In fact the 1st one is already defined in events/core.c and bnx2x_sp.c, so the patch simply moves the definition to list.h. Signed-off-by: Oleg Nesterov Cc: Eilon Greenstein Cc: Greg Kroah-Hartman Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/list.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux/list.h') diff --git a/include/linux/list.h b/include/linux/list.h index f4d8a2f12a33..2ece63847001 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -372,6 +372,22 @@ static inline void list_splice_tail_init(struct list_head *list, #define list_first_entry_or_null(ptr, type, member) \ (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL) +/** + * list_next_entry - get the next element in list + * @pos: the type * to cursor + * @member: the name of the list_struct 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_struct within the struct. + */ +#define list_prev_entry(pos, member) \ + list_entry((pos)->member.prev, typeof(*(pos)), member) + /** * list_for_each - iterate over a list * @pos: the &struct list_head to use as a loop cursor. -- cgit v1.2.3 From 8120e2e5141a420edee725ff28f18aa264795f7a Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 12 Nov 2013 15:10:02 -0800 Subject: list: change list_for_each_entry*() to use list_*_entry() Now that we have list_{next,prev}_entry() we can change list_for_each_entry*() and list_safe_reset_next() to use the new helpers to improve the readability. Signed-off-by: Oleg Nesterov Cc: Eilon Greenstein Cc: Greg Kroah-Hartman Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/list.h | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) (limited to 'include/linux/list.h') diff --git a/include/linux/list.h b/include/linux/list.h index 2ece63847001..c88a591d1c02 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -433,8 +433,8 @@ static inline void list_splice_tail_init(struct list_head *list, */ #define list_for_each_entry(pos, head, member) \ for (pos = list_entry((head)->next, typeof(*pos), member); \ - &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), member)) + &pos->member != (head); \ + pos = list_next_entry(pos, member)) /** * list_for_each_entry_reverse - iterate backwards over list of given type. @@ -444,8 +444,8 @@ static inline void list_splice_tail_init(struct list_head *list, */ #define list_for_each_entry_reverse(pos, head, member) \ for (pos = list_entry((head)->prev, typeof(*pos), member); \ - &pos->member != (head); \ - pos = list_entry(pos->member.prev, typeof(*pos), member)) + &pos->member != (head); \ + pos = list_prev_entry(pos, member)) /** * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue() @@ -468,9 +468,9 @@ static inline void list_splice_tail_init(struct list_head *list, * the current position. */ #define list_for_each_entry_continue(pos, head, member) \ - for (pos = list_entry(pos->member.next, typeof(*pos), member); \ - &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), member)) + for (pos = list_next_entry(pos, member); \ + &pos->member != (head); \ + pos = list_next_entry(pos, member)) /** * list_for_each_entry_continue_reverse - iterate backwards from the given point @@ -482,9 +482,9 @@ static inline void list_splice_tail_init(struct list_head *list, * the current position. */ #define list_for_each_entry_continue_reverse(pos, head, member) \ - for (pos = list_entry(pos->member.prev, typeof(*pos), member); \ - &pos->member != (head); \ - pos = list_entry(pos->member.prev, typeof(*pos), member)) + for (pos = list_prev_entry(pos, member); \ + &pos->member != (head); \ + pos = list_prev_entry(pos, member)) /** * list_for_each_entry_from - iterate over list of given type from the current point @@ -495,8 +495,8 @@ static inline void list_splice_tail_init(struct list_head *list, * Iterate over list of given type, continuing from current position. */ #define list_for_each_entry_from(pos, head, member) \ - for (; &pos->member != (head); \ - pos = list_entry(pos->member.next, typeof(*pos), member)) + for (; &pos->member != (head); \ + pos = list_next_entry(pos, member)) /** * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry @@ -507,9 +507,9 @@ static inline void list_splice_tail_init(struct list_head *list, */ #define list_for_each_entry_safe(pos, n, head, member) \ for (pos = list_entry((head)->next, typeof(*pos), member), \ - n = list_entry(pos->member.next, typeof(*pos), member); \ + n = list_next_entry(pos, member); \ &pos->member != (head); \ - pos = n, n = list_entry(n->member.next, typeof(*n), member)) + pos = n, n = list_next_entry(n, member)) /** * list_for_each_entry_safe_continue - continue list iteration safe against removal @@ -522,10 +522,10 @@ static inline void list_splice_tail_init(struct list_head *list, * safe against removal of list entry. */ #define list_for_each_entry_safe_continue(pos, n, head, member) \ - for (pos = list_entry(pos->member.next, typeof(*pos), member), \ - n = list_entry(pos->member.next, typeof(*pos), member); \ + for (pos = list_next_entry(pos, member), \ + n = list_next_entry(pos, member); \ &pos->member != (head); \ - pos = n, n = list_entry(n->member.next, typeof(*n), member)) + pos = n, n = list_next_entry(n, member)) /** * list_for_each_entry_safe_from - iterate over list from current point safe against removal @@ -538,9 +538,9 @@ static inline void list_splice_tail_init(struct list_head *list, * removal of list entry. */ #define list_for_each_entry_safe_from(pos, n, head, member) \ - for (n = list_entry(pos->member.next, typeof(*pos), member); \ + for (n = list_next_entry(pos, member); \ &pos->member != (head); \ - pos = n, n = list_entry(n->member.next, typeof(*n), member)) + pos = n, n = list_next_entry(n, member)) /** * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal @@ -554,9 +554,9 @@ static inline void list_splice_tail_init(struct list_head *list, */ #define list_for_each_entry_safe_reverse(pos, n, head, member) \ for (pos = list_entry((head)->prev, typeof(*pos), member), \ - n = list_entry(pos->member.prev, typeof(*pos), member); \ + n = list_prev_entry(pos, member); \ &pos->member != (head); \ - pos = n, n = list_entry(n->member.prev, typeof(*n), member)) + pos = n, n = list_prev_entry(n, member)) /** * list_safe_reset_next - reset a stale list_for_each_entry_safe loop @@ -571,7 +571,7 @@ static inline void list_splice_tail_init(struct list_head *list, * completing the current iteration of the loop body. */ #define list_safe_reset_next(pos, n, member) \ - n = list_entry(pos->member.next, typeof(*pos), member) + n = list_next_entry(pos, member) /* * Double linked lists with a single pointer list head. -- cgit v1.2.3 From 93be3c2eb3371f022ad88acf1ab6bee8e3c38378 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 12 Nov 2013 15:10:03 -0800 Subject: list: introduce list_last_entry(), use list_{first,last}_entry() We already have list_first_entry(), it makes sense to also add list_last_entry() for consistency. And we use both helpers in list_for_each_*(). Signed-off-by: Oleg Nesterov Cc: Eilon Greenstein Cc: Greg Kroah-Hartman Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/list.h | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'include/linux/list.h') diff --git a/include/linux/list.h b/include/linux/list.h index c88a591d1c02..ef9594171062 100644 --- a/include/linux/list.h +++ b/include/linux/list.h @@ -361,6 +361,17 @@ static inline void list_splice_tail_init(struct list_head *list, #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_struct 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_first_entry_or_null - get the first element from a list * @ptr: the list head to take the element from. @@ -432,7 +443,7 @@ static inline void list_splice_tail_init(struct list_head *list, * @member: the name of the list_struct within the struct. */ #define list_for_each_entry(pos, head, member) \ - for (pos = list_entry((head)->next, typeof(*pos), member); \ + for (pos = list_first_entry(head, typeof(*pos), member); \ &pos->member != (head); \ pos = list_next_entry(pos, member)) @@ -443,7 +454,7 @@ static inline void list_splice_tail_init(struct list_head *list, * @member: the name of the list_struct within the struct. */ #define list_for_each_entry_reverse(pos, head, member) \ - for (pos = list_entry((head)->prev, typeof(*pos), member); \ + for (pos = list_last_entry(head, typeof(*pos), member); \ &pos->member != (head); \ pos = list_prev_entry(pos, member)) @@ -506,7 +517,7 @@ static inline void list_splice_tail_init(struct list_head *list, * @member: the name of the list_struct within the struct. */ #define list_for_each_entry_safe(pos, n, head, member) \ - for (pos = list_entry((head)->next, typeof(*pos), member), \ + for (pos = list_first_entry(head, typeof(*pos), member), \ n = list_next_entry(pos, member); \ &pos->member != (head); \ pos = n, n = list_next_entry(n, member)) @@ -553,7 +564,7 @@ static inline void list_splice_tail_init(struct list_head *list, * of list entry. */ #define list_for_each_entry_safe_reverse(pos, n, head, member) \ - for (pos = list_entry((head)->prev, typeof(*pos), member), \ + for (pos = list_last_entry(head, typeof(*pos), member), \ n = list_prev_entry(pos, member); \ &pos->member != (head); \ pos = n, n = list_prev_entry(n, member)) -- cgit v1.2.3