list.h: drop prefetch()

Around the same time as the initial import of list.h, Linus removed
all the prefetch() stuff from the kernel's list.h (75d65a425c01 and
e66eed651fd1, with a followup later in c0d15cc7ee8c).

Make our list.h a little easier to read and a little closer to
upstream's version by removing the stubbed-out prefetching.

Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

list.h

@@ -13,7 +13,6 @@
 
 #define LIST_POISON1  ((void *) 0x00100100)
 #define LIST_POISON2  ((void *) 0x00200200)
-static inline void prefetch(const void *x) {;}
 
 struct list_head {
 	struct list_head *next, *prev;
@@ -275,29 +274,16 @@ static inline void list_splice_init(struct list_head *list,
  * @head:	the head for your list.
  */
 #define list_for_each(pos, head) \
-	for (pos = (head)->next; prefetch(pos->next), pos != (head); \
+	for (pos = (head)->next; pos != (head); \
 		pos = pos->next)
 
-/**
- * __list_for_each	-	iterate over a list
- * @pos:	the &struct list_head to use as a loop cursor.
- * @head:	the head for your list.
- *
- * This variant differs from list_for_each() in that it's the
- * simplest possible list iteration code, no prefetching is done.
- * Use this for code that knows the list to be very short (empty
- * or 1 entry) most of the time.
- */
-#define __list_for_each(pos, head) \
-	for (pos = (head)->next; pos != (head); pos = pos->next)
-
 /**
  * list_for_each_prev	-	iterate over a list backwards
  * @pos:	the &struct list_head to use as a loop cursor.
  * @head:	the head for your list.
  */
 #define list_for_each_prev(pos, head) \
-	for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
+	for (pos = (head)->prev; pos != (head); \
 		pos = pos->prev)
 
 /**
@@ -318,7 +304,7 @@ static inline void list_splice_init(struct list_head *list,
  */
 #define list_for_each_entry(pos, head, member)				\
 	for (pos = list_entry((head)->next, typeof(*pos), member);	\
-	     prefetch(pos->member.next), &pos->member != (head); 	\
+	     &pos->member != (head);					\
 	     pos = list_entry(pos->member.next, typeof(*pos), member))
 
 /**
@@ -329,7 +315,7 @@ static inline void list_splice_init(struct list_head *list,
  */
 #define list_for_each_entry_reverse(pos, head, member)			\
 	for (pos = list_entry((head)->prev, typeof(*pos), member);	\
-	     prefetch(pos->member.prev), &pos->member != (head); 	\
+	     &pos->member != (head);					\
 	     pos = list_entry(pos->member.prev, typeof(*pos), member))
 
 /**
@@ -354,7 +340,7 @@ static inline void list_splice_init(struct list_head *list,
  */
 #define list_for_each_entry_continue(pos, head, member) 		\
 	for (pos = list_entry(pos->member.next, typeof(*pos), member);	\
-	     prefetch(pos->member.next), &pos->member != (head);	\
+	     &pos->member != (head);					\
 	     pos = list_entry(pos->member.next, typeof(*pos), member))
 
 /**
@@ -366,7 +352,7 @@ static inline void list_splice_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 (; prefetch(pos->member.next), &pos->member != (head);	\
+	for (; &pos->member != (head);					\
 	     pos = list_entry(pos->member.next, typeof(*pos), member))
 
 /**
@@ -545,7 +531,7 @@ static inline void hlist_add_after(struct hlist_node *n,
 #define hlist_entry(ptr, type, member) container_of(ptr,type,member)
 
 #define hlist_for_each(pos, head) \
-	for (pos = (head)->first; pos && ({ prefetch(pos->next); 1; }); \
+	for (pos = (head)->first; pos; \
 	     pos = pos->next)
 
 #define hlist_for_each_safe(pos, n, head) \
@@ -561,7 +547,7 @@ static inline void hlist_add_after(struct hlist_node *n,
  */
 #define hlist_for_each_entry(tpos, pos, head, member)			 \
 	for (pos = (head)->first;					 \
-	     pos && ({ prefetch(pos->next); 1;}) &&			 \
+	     pos &&							 \
 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
 	     pos = pos->next)
 
@@ -573,7 +559,7 @@ static inline void hlist_add_after(struct hlist_node *n,
  */
 #define hlist_for_each_entry_continue(tpos, pos, member)		 \
 	for (pos = (pos)->next;						 \
-	     pos && ({ prefetch(pos->next); 1;}) &&			 \
+	     pos &&							 \
 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
 	     pos = pos->next)
 
@@ -584,7 +570,7 @@ static inline void hlist_add_after(struct hlist_node *n,
  * @member:	the name of the hlist_node within the struct.
  */
 #define hlist_for_each_entry_from(tpos, pos, member)			 \
-	for (; pos && ({ prefetch(pos->next); 1;}) &&			 \
+	for (; pos &&							 \
 		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
 	     pos = pos->next)