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>
diff --git a/include/linux/plist.h b/include/linux/plist.h
index aa0fb39..c815491 100644
--- a/include/linux/plist.h
+++ b/include/linux/plist.h
@@ -98,6 +98,13 @@
}
/**
+ * 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
* @__prio: initial node priority
@@ -143,6 +150,16 @@
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
* @n: another type * to use as temporary storage
@@ -163,6 +180,18 @@
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
* @n: another type * to use as temporary storage
@@ -229,6 +258,20 @@
#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
*