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 <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Shaohua Li <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Dan Streetman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Christian Ehrhardt <[email protected]>
Cc: Weijie Yang <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Bob Liu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions