rculist.h: introduce list_entry_rcu() and list_first_entry_rcu()

	at->prev = last;

}

/**

 * list_entry_rcu - get the struct for this entry

 * @ptr:        the &struct list_head pointer.

 * @type:       the type of the struct this is embedded in.

 * @member:     the name of the list_struct within the struct.

 *

 * This primitive may safely run concurrently with the _rcu list-mutation

 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().

 */

#define list_entry_rcu(ptr, type, member) \

	container_of(rcu_dereference(ptr), type, member)

/**

 * list_first_entry_rcu - 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.

 * @member:     the name of the list_struct within the struct.

 *

 * Note, that list is expected to be not empty.

 *

 * This primitive may safely run concurrently with the _rcu list-mutation

 * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().

 */

#define list_first_entry_rcu(ptr, type, member) \

	list_entry_rcu((ptr)->next, type, member)

#define __list_for_each_rcu(pos, head) \

	for (pos = rcu_dereference((head)->next); \

		pos != (head); \

 * as long as the traversal is guarded by rcu_read_lock().

 */

#define list_for_each_entry_rcu(pos, head, member) \

	for (pos = list_entry(rcu_dereference((head)->next), typeof(*pos), member); \

	for (pos = list_entry_rcu((head)->next, typeof(*pos), member); \

		prefetch(pos->member.next), &pos->member != (head); \

		pos = list_entry(rcu_dereference(pos->member.next), typeof(*pos), member))

		pos = list_entry_rcu(pos->member.next, typeof(*pos), member))

/**