1 files changed, 39 insertions, 16 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
index 969f6e92d089..9a5f8a71810c 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -1,10 +1,10 @@
 #ifndef _LINUX_LIST_H
 #define _LINUX_LIST_H
 
+#include <linux/types.h>
 #include <linux/stddef.h>
 #include <linux/poison.h>
 #include <linux/prefetch.h>
-#include <asm/system.h>
 
 /*
  * Simple doubly linked list implementation.
@@ -16,10 +16,6 @@
  * using the generic single-entry routines.
  */
 
-struct list_head {
-	struct list_head *next, *prev;
-};
-
 #define LIST_HEAD_INIT(name) { &(name), &(name) }
 
 #define LIST_HEAD(name) \
@@ -206,6 +202,20 @@ static inline int list_empty_careful(const struct list_head *head)
 }
 
 /**
+ * list_rotate_left - rotate the list to the left
+ * @head: the head of the list
+ */
+static inline void list_rotate_left(struct list_head *head)
+{
+	struct list_head *first;
+
+	if (!list_empty(head)) {
+		first = head->next;
+		list_move_tail(first, head);
+	}
+}
+
+/**
  * list_is_singular - tests whether a list has just one entry.
  * @head: the list to test.
  */
@@ -484,7 +494,7 @@ static inline void list_splice_tail_init(struct list_head *list,
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
- * list_for_each_entry_safe_continue
+ * list_for_each_entry_safe_continue - continue list iteration safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
@@ -500,7 +510,7 @@ static inline void list_splice_tail_init(struct list_head *list,
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
- * list_for_each_entry_safe_from
+ * list_for_each_entry_safe_from - iterate over list from current point safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
@@ -515,7 +525,7 @@ static inline void list_splice_tail_init(struct list_head *list,
 	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
 /**
- * list_for_each_entry_safe_reverse
+ * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
  * @pos:	the type * to use as a loop cursor.
  * @n:		another type * to use as temporary storage
  * @head:	the head for your list.
@@ -530,6 +540,21 @@ static inline void list_splice_tail_init(struct list_head *list,
 	     &pos->member != (head); 					\
 	     pos = n, n = list_entry(n->member.prev, typeof(*n), member))
 
+/**
+ * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
+ * @pos:	the loop cursor used in the list_for_each_entry_safe loop
+ * @n:		temporary storage used in list_for_each_entry_safe
+ * @member:	the name of the list_struct within the struct.
+ *
+ * list_safe_reset_next is not safe to use in general if the list may be
+ * modified concurrently (eg. the lock is dropped in the loop body). An
+ * exception to this is if the cursor element (pos) is pinned in the list,
+ * and list_safe_reset_next is called after re-taking the lock and before
+ * 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)
+
 /*
  * Double linked lists with a single pointer list head.
  * Mostly useful for hash tables where the two pointer list head is
@@ -537,14 +562,6 @@ static inline void list_splice_tail_init(struct list_head *list,
  * You lose the ability to access the tail in O(1).
  */
 
-struct hlist_head {
-	struct hlist_node *first;
-};
-
-struct hlist_node {
-	struct hlist_node *next, **pprev;
-};
-
 #define HLIST_HEAD_INIT { .first = NULL }
 #define HLIST_HEAD(name) struct hlist_head name = {  .first = NULL }
 #define INIT_HLIST_HEAD(ptr) ((ptr)->first = NULL)
@@ -619,6 +636,12 @@ static inline void hlist_add_after(struct hlist_node *n,
 		next->next->pprev  = &next->next;
 }
 
+/* after that we'll appear to be on some hlist and hlist_del will work */
+static inline void hlist_add_fake(struct hlist_node *n)
+{
+	n->pprev = &n->next;
+}
+
 /*
  * Move a list from one list head to another. Fixup the pprev
  * reference of the first entry if it exists.