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 <ddstreet@ieee.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Cc: Weijie Yang <weijieut@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Dan Streetman 2014-06-04 16:09:55 -07:00 committed by Linus Torvalds
parent adfab836f4
commit fd16618e12

View File

@ -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