[PATCH v4 01/16] rcu: Define notrace version of list_for_each_entry_rcu and list_entry_rcu

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This defines list_for_each_entry_rcu_notrace which uses
new list_entry_rcu_notrace which uses rcu_dereference_raw_notrace instead
of rcu_dereference_raw whici allows us using
list_for_each_entry_rcu_notrace when MMU is off (real mode).

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 include/linux/rculist.h | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index 8183b46..a155774 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -253,6 +253,25 @@ static inline void list_splice_init_rcu(struct list_head *list,
 })
 
 /**
+ * list_entry_rcu_notrace - 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().
+ *
+ * This is the same as list_entry_rcu() except that it does
+ * not do any RCU debugging or tracing.
+ */
+#define list_entry_rcu_notrace(ptr, type, member) \
+({ \
+	typeof(*ptr) __rcu *__ptr = (typeof(*ptr) __rcu __force *)ptr; \
+	container_of((typeof(ptr))rcu_dereference_raw_notrace(__ptr), \
+			type, member); \
+})
+
+/**
  * Where are list_empty_rcu() and list_first_entry_rcu()?
  *
  * Implementing those functions following their counterparts list_empty() and
@@ -308,6 +327,25 @@ static inline void list_splice_init_rcu(struct list_head *list,
 		pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
 
 /**
+ * list_for_each_entry_rcu_notrace - iterate over rcu list of given type
+ * @pos:	the type * to use as a loop cursor.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ *
+ * This list-traversal primitive may safely run concurrently with
+ * the _rcu list-mutation primitives such as list_add_rcu()
+ * as long as the traversal is guarded by rcu_read_lock().
+ *
+ * This is the same as list_for_each_entry_rcu() except that it does
+ * not do any RCU debugging or tracing.
+ */
+#define list_for_each_entry_rcu_notrace(pos, head, member) \
+	for (pos = list_entry_rcu_notrace((head)->next, typeof(*pos), member); \
+		&pos->member != (head); \
+		pos = list_entry_rcu_notrace(pos->member.next, typeof(*pos), \
+				member))
+
+/**
  * list_for_each_entry_continue_rcu - continue iteration over list of given type
  * @pos:	the type * to use as a loop cursor.
  * @head:	the head for your list.
-- 
2.0.0