1 files changed, 53 insertions, 26 deletions

diff --git a/include/linux/list.h b/include/linux/list.h
index f4d8a2f12a33..ef9594171062 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -362,6 +362,17 @@ static inline void list_splice_tail_init(struct list_head *list,
         list_entry((ptr)->next, type, member)
 
 /**
+ * list_last_entry - get the last element from a list
+ * @ptr:        the list head to take the element from.
+ * @type:       the type of the struct this is embedded in.
+ * @member:     the name of the list_struct within the struct.
+ *
+ * Note, that list is expected to be not empty.
+ */
+#define list_last_entry(ptr, type, member) \
+        list_entry((ptr)->prev, type, member)
+
+/**
  * list_first_entry_or_null - get the first element from a list
  * @ptr:        the list head to take the element from.
  * @type:       the type of the struct this is embedded in.
@@ -373,6 +384,22 @@ static inline void list_splice_tail_init(struct list_head *list,
         (!list_empty(ptr) ? list_first_entry(ptr, type, member) : NULL)
 
 /**
+ * list_next_entry - get the next element in list
+ * @pos:        the type * to cursor
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_next_entry(pos, member) \
+        list_entry((pos)->member.next, typeof(*(pos)), member)
+
+/**
+ * list_prev_entry - get the prev element in list
+ * @pos:        the type * to cursor
+ * @member:     the name of the list_struct within the struct.
+ */
+#define list_prev_entry(pos, member) \
+        list_entry((pos)->member.prev, typeof(*(pos)), member)
+
+/**
  * list_for_each        -       iterate over a list
  * @pos:        the &struct list_head to use as a loop cursor.
  * @head:       the head for your list.
@@ -416,9 +443,9 @@ static inline void list_splice_tail_init(struct list_head *list,
  * @member:     the name of the list_struct within the struct.
  */
 #define list_for_each_entry(pos, head, member)                          \
-        for (pos = list_entry((head)->next, typeof(*pos), member);      \
-             &pos->member != (head);    \
-             pos = list_entry(pos->member.next, typeof(*pos), member))
+        for (pos = list_first_entry(head, typeof(*pos), member);        \
+             &pos->member != (head);                                    \
+             pos = list_next_entry(pos, member))
 
 /**
  * list_for_each_entry_reverse - iterate backwards over list of given type.
@@ -427,9 +454,9 @@ static inline void list_splice_tail_init(struct list_head *list,
  * @member:     the name of the list_struct within the struct.
  */
 #define list_for_each_entry_reverse(pos, head, member)                  \
-        for (pos = list_entry((head)->prev, typeof(*pos), member);      \
-             &pos->member != (head);    \
-             pos = list_entry(pos->member.prev, typeof(*pos), member))
+        for (pos = list_last_entry(head, typeof(*pos), member);         \
+             &pos->member != (head);                                    \
+             pos = list_prev_entry(pos, member))
 
 /**
  * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
@@ -452,9 +479,9 @@ static inline void list_splice_tail_init(struct list_head *list,
  * the current position.
  */
 #define list_for_each_entry_continue(pos, head, member)                 \
-        for (pos = list_entry(pos->member.next, typeof(*pos), member);  \
-             &pos->member != (head);    \
-             pos = list_entry(pos->member.next, typeof(*pos), member))
+        for (pos = list_next_entry(pos, member);                        \
+             &pos->member != (head);                                    \
+             pos = list_next_entry(pos, member))
 
 /**
  * list_for_each_entry_continue_reverse - iterate backwards from the given point
@@ -466,9 +493,9 @@ static inline void list_splice_tail_init(struct list_head *list,
  * the current position.
  */
 #define list_for_each_entry_continue_reverse(pos, head, member)         \
-        for (pos = list_entry(pos->member.prev, typeof(*pos), member);  \
-             &pos->member != (head);    \
-             pos = list_entry(pos->member.prev, typeof(*pos), member))
+        for (pos = list_prev_entry(pos, member);                        \
+             &pos->member != (head);                                    \
+             pos = list_prev_entry(pos, member))
 
 /**
  * list_for_each_entry_from - iterate over list of given type from the current point
@@ -479,8 +506,8 @@ static inline void list_splice_tail_init(struct list_head *list,
  * Iterate over list of given type, continuing from current position.
  */
 #define list_for_each_entry_from(pos, head, member)                     \
-        for (; &pos->member != (head);  \
-             pos = list_entry(pos->member.next, typeof(*pos), member))
+        for (; &pos->member != (head);                                  \
+             pos = list_next_entry(pos, member))
 
 /**
  * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
@@ -490,10 +517,10 @@ static inline void list_splice_tail_init(struct list_head *list,
  * @member:     the name of the list_struct within the struct.
  */
 #define list_for_each_entry_safe(pos, n, head, member)                  \
-        for (pos = list_entry((head)->next, typeof(*pos), member),      \
-                n = list_entry(pos->member.next, typeof(*pos), member); \
+        for (pos = list_first_entry(head, typeof(*pos), member),        \
+                n = list_next_entry(pos, member);                       \
              &pos->member != (head);                                    \
-             pos = n, n = list_entry(n->member.next, typeof(*n), member))
+             pos = n, n = list_next_entry(n, member))
 
 /**
  * list_for_each_entry_safe_continue - continue list iteration safe against removal
@@ -506,10 +533,10 @@ static inline void list_splice_tail_init(struct list_head *list,
  * safe against removal of list entry.
  */
 #define list_for_each_entry_safe_continue(pos, n, head, member)                 \
-        for (pos = list_entry(pos->member.next, typeof(*pos), member),          \
-                n = list_entry(pos->member.next, typeof(*pos), member);         \
+        for (pos = list_next_entry(pos, member),                                \
+                n = list_next_entry(pos, member);                               \
              &pos->member != (head);                                            \
-             pos = n, n = list_entry(n->member.next, typeof(*n), member))
+             pos = n, n = list_next_entry(n, member))
 
 /**
  * list_for_each_entry_safe_from - iterate over list from current point safe against removal
@@ -522,9 +549,9 @@ static inline void list_splice_tail_init(struct list_head *list,
  * removal of list entry.
  */
 #define list_for_each_entry_safe_from(pos, n, head, member)                     \
-        for (n = list_entry(pos->member.next, typeof(*pos), member);            \
+        for (n = list_next_entry(pos, member);                                  \
              &pos->member != (head);                                            \
-             pos = n, n = list_entry(n->member.next, typeof(*n), member))
+             pos = n, n = list_next_entry(n, member))
 
 /**
  * list_for_each_entry_safe_reverse - iterate backwards over list safe against removal
@@ -537,10 +564,10 @@ static inline void list_splice_tail_init(struct list_head *list,
  * of list entry.
  */
 #define list_for_each_entry_safe_reverse(pos, n, head, member)          \
-        for (pos = list_entry((head)->prev, typeof(*pos), member),      \
-                n = list_entry(pos->member.prev, typeof(*pos), member); \
+        for (pos = list_last_entry(head, typeof(*pos), member),         \
+                n = list_prev_entry(pos, member);                       \
              &pos->member != (head);                                    \
-             pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+             pos = n, n = list_prev_entry(n, member))
 
 /**
  * list_safe_reset_next - reset a stale list_for_each_entry_safe loop
@@ -555,7 +582,7 @@ static inline void list_splice_tail_init(struct list_head *list,
  * 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)
+        n = list_next_entry(pos, member)
 
 /*
  * Double linked lists with a single pointer list head.