From fd16618e12a05df79a3439d72d5ffdac5d34f3da Mon Sep 17 00:00:00 2001 From: Dan Streetman Date: Wed, 4 Jun 2014 16:09:55 -0700 Subject: [PATCH] lib/plist: add helper functions Add PLIST_HEAD() to plist.h, equivalent to LIST_HEAD() from list.h, to define and initialize a struct plist_head. Add plist_for_each_continue() and plist_for_each_entry_continue(), equivalent to list_for_each_continue() and list_for_each_entry_continue(), to iterate over a plist continuing after the current position. Add plist_prev() and plist_next(), equivalent to (struct list_head*)->prev and ->next, implemented by list_prev_entry() and list_next_entry(), to access the prev/next struct plist_node entry. These are needed because unlike struct list_head, direct access of the prev/next struct plist_node isn't possible; the list must be navigated via the contained struct list_head. e.g. instead of accessing the prev by list_prev_entry(node, node_list) it can be accessed by plist_prev(node). Signed-off-by: Dan Streetman Acked-by: Mel Gorman Cc: Paul Gortmaker Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Shaohua Li Cc: Hugh Dickins Cc: Dan Streetman Cc: Michal Hocko Cc: Christian Ehrhardt Cc: Weijie Yang Cc: Rik van Riel Cc: Johannes Weiner Cc: Bob Liu Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/plist.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/include/linux/plist.h b/include/linux/plist.h index aa0fb390bd29..c81549119bd4 100644 --- a/include/linux/plist.h +++ b/include/linux/plist.h @@ -97,6 +97,13 @@ struct plist_node { .node_list = LIST_HEAD_INIT((head).node_list) \ } +/** + * PLIST_HEAD - declare and init plist_head + * @head: name for struct plist_head variable + */ +#define PLIST_HEAD(head) \ + struct plist_head head = PLIST_HEAD_INIT(head) + /** * PLIST_NODE_INIT - static struct plist_node initializer * @node: struct plist_node variable name @@ -142,6 +149,16 @@ extern void plist_del(struct plist_node *node, struct plist_head *head); #define plist_for_each(pos, head) \ list_for_each_entry(pos, &(head)->node_list, node_list) +/** + * plist_for_each_continue - continue iteration over the plist + * @pos: the type * to use as a loop cursor + * @head: the head for your list + * + * Continue to iterate over plist, continuing after the current position. + */ +#define plist_for_each_continue(pos, head) \ + list_for_each_entry_continue(pos, &(head)->node_list, node_list) + /** * plist_for_each_safe - iterate safely over a plist of given type * @pos: the type * to use as a loop counter @@ -162,6 +179,18 @@ extern void plist_del(struct plist_node *node, struct plist_head *head); #define plist_for_each_entry(pos, head, mem) \ list_for_each_entry(pos, &(head)->node_list, mem.node_list) +/** + * plist_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 + * @m: the name of the list_struct within the struct + * + * Continue to iterate over list of given type, continuing after + * the current position. + */ +#define plist_for_each_entry_continue(pos, head, m) \ + list_for_each_entry_continue(pos, &(head)->node_list, m.node_list) + /** * plist_for_each_entry_safe - iterate safely over list of given type * @pos: the type * to use as a loop counter @@ -228,6 +257,20 @@ static inline int plist_node_empty(const struct plist_node *node) container_of(plist_last(head), type, member) #endif +/** + * plist_next - get the next entry in list + * @pos: the type * to cursor + */ +#define plist_next(pos) \ + list_next_entry(pos, node_list) + +/** + * plist_prev - get the prev entry in list + * @pos: the type * to cursor + */ +#define plist_prev(pos) \ + list_prev_entry(pos, node_list) + /** * plist_first - return the first node (and thus, highest priority) * @head: the &struct plist_head pointer -- 2.20.1