entry->prev = LIST_POISON2;
}
+/*
+ * list_replace_rcu - replace old entry by new one
+ * @old : the element to be replaced
+ * @new : the new element to insert
+ *
+ * The old entry will be replaced with the new entry atomically.
+ */
+static inline void list_replace_rcu(struct list_head *old, struct list_head *new){
+ new->next = old->next;
+ new->prev = old->prev;
+ smp_wmb();
+ new->next->prev = new;
+ new->prev->next = new;
+}
+
/**
* list_del_init - deletes entry from list and reinitialize it.
* @entry: the element to delete from the list.
* @head: the head for your list.
*/
#define list_for_each(pos, head) \
- for (pos = (head)->next, prefetch(pos->next); pos != (head); \
- pos = pos->next, prefetch(pos->next))
+ for (pos = (head)->next; prefetch(pos->next), pos != (head); \
+ pos = pos->next)
/**
* __list_for_each - iterate over a list
* @head: the head for your list.
*/
#define list_for_each_prev(pos, head) \
- for (pos = (head)->prev, prefetch(pos->prev); pos != (head); \
- pos = pos->prev, prefetch(pos->prev))
+ for (pos = (head)->prev; prefetch(pos->prev), pos != (head); \
+ pos = pos->prev)
/**
* list_for_each_safe - iterate over a list safe against removal of list entry
* @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), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next))
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ prefetch(pos->member.next), &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_reverse - iterate backwards over list of given type.
* @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), \
- prefetch(pos->member.prev); \
- &pos->member != (head); \
- pos = list_entry(pos->member.prev, typeof(*pos), member), \
- prefetch(pos->member.prev))
+ for (pos = list_entry((head)->prev, typeof(*pos), member); \
+ prefetch(pos->member.prev), &pos->member != (head); \
+ pos = list_entry(pos->member.prev, typeof(*pos), member))
/**
* list_prepare_entry - prepare a pos entry for use as a start point in
* @member: the name of the list_struct within the struct.
*/
#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 = list_entry(pos->member.next, typeof(*pos), member), \
- prefetch(pos->member.next))
+ for (pos = list_entry(pos->member.next, typeof(*pos), member); \
+ prefetch(pos->member.next), &pos->member != (head); \
+ pos = list_entry(pos->member.next, typeof(*pos), member))
/**
* list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_rcu(pos, head) \
- for (pos = (head)->next, prefetch(pos->next); pos != (head); \
- pos = pos->next, ({ smp_read_barrier_depends(); 0;}), prefetch(pos->next))
+ for (pos = (head)->next; prefetch(pos->next), pos != (head); \
+ pos = rcu_dereference(pos->next))
#define __list_for_each_rcu(pos, head) \
for (pos = (head)->next; pos != (head); \
- pos = pos->next, ({ smp_read_barrier_depends(); 0;}))
+ pos = rcu_dereference(pos->next))
/**
* list_for_each_safe_rcu - iterate over an rcu-protected list safe
*/
#define list_for_each_safe_rcu(pos, n, head) \
for (pos = (head)->next, n = pos->next; pos != (head); \
- pos = n, ({ smp_read_barrier_depends(); 0;}), n = pos->next)
+ pos = rcu_dereference(n), n = pos->next)
/**
* list_for_each_entry_rcu - iterate over rcu list of given type
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_entry_rcu(pos, head, member) \
- for (pos = list_entry((head)->next, typeof(*pos), member), \
- prefetch(pos->member.next); \
- &pos->member != (head); \
- pos = list_entry(pos->member.next, typeof(*pos), member), \
- ({ smp_read_barrier_depends(); 0;}), \
- prefetch(pos->member.next))
+ for (pos = list_entry((head)->next, typeof(*pos), member); \
+ prefetch(pos->member.next), &pos->member != (head); \
+ pos = rcu_dereference(list_entry(pos->member.next, \
+ typeof(*pos), member)))
/**
* as long as the traversal is guarded by rcu_read_lock().
*/
#define list_for_each_continue_rcu(pos, head) \
- for ((pos) = (pos)->next, prefetch((pos)->next); (pos) != (head); \
- (pos) = (pos)->next, ({ smp_read_barrier_depends(); 0;}), prefetch((pos)->next))
+ for ((pos) = (pos)->next; prefetch((pos)->next), (pos) != (head); \
+ (pos) = rcu_dereference((pos)->next))
/*
* Double linked lists with a single pointer list head.
}
}
-#define hlist_del_rcu_init hlist_del_init
-
static inline void hlist_add_head(struct hlist_node *n, struct hlist_head *h)
{
struct hlist_node *first = h->first;
* or hlist_del_rcu(), running on this same list.
* However, it is perfectly legal to run concurrently with
* the _rcu list-traversal primitives, such as
- * hlist_for_each_entry(), but only if smp_read_barrier_depends()
- * is used to prevent memory-consistency problems on Alpha CPUs.
- * Regardless of the type of CPU, the list-traversal primitive
- * must be guarded by rcu_read_lock().
- *
- * OK, so why don't we have an hlist_for_each_entry_rcu()???
+ * hlist_for_each_rcu(), used to prevent memory-consistency
+ * problems on Alpha CPUs. Regardless of the type of CPU, the
+ * list-traversal primitive must be guarded by rcu_read_lock().
*/
static inline void hlist_add_head_rcu(struct hlist_node *n,
struct hlist_head *h)
for (pos = (head)->first; pos && ({ n = pos->next; 1; }); \
pos = n)
+#define hlist_for_each_rcu(pos, head) \
+ for ((pos) = (head)->first; pos && ({ prefetch((pos)->next); 1; }); \
+ (pos) = rcu_dereference((pos)->next))
+
/**
* hlist_for_each_entry - iterate over list of given type
* @tpos: the type * to use as a loop counter.
for (pos = (head)->first; \
pos && ({ prefetch(pos->next); 1;}) && \
({ tpos = hlist_entry(pos, typeof(*tpos), member); 1;}); \
- pos = pos->next, ({ smp_read_barrier_depends(); 0; }) )
+ pos = rcu_dereference(pos->next))
#else
#warning "don't include kernel headers in userspace"