X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=include%2Flinux%2Flist.h;h=f9d71eab05eecc9a7d3891d346b86aa58d24233b;hb=a999589ccaae16472531e0616f23826ad097aa40;hp=65a5b5ceda4947d1478bba79abbda826963d128e;hpb=57cad8084e0837e0f2c97da789ec9b3f36809be9;p=linux-2.6-omap-h63xx.git

diff --git a/include/linux/list.h b/include/linux/list.h
index 65a5b5ceda4..f9d71eab05e 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -39,6 +39,7 @@ static inline void INIT_LIST_HEAD(struct list_head *list)
  * This is only for internal list manipulation where we know
  * the prev/next entries already!
  */
+#ifndef CONFIG_DEBUG_LIST
 static inline void __list_add(struct list_head *new,
 			      struct list_head *prev,
 			      struct list_head *next)
@@ -48,6 +49,11 @@ static inline void __list_add(struct list_head *new,
 	new->prev = prev;
 	prev->next = new;
 }
+#else
+extern void __list_add(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next);
+#endif
 
 /**
  * list_add - add a new entry
@@ -57,10 +63,15 @@ static inline void __list_add(struct list_head *new,
  * Insert a new entry after the specified head.
  * This is good for implementing stacks.
  */
+#ifndef CONFIG_DEBUG_LIST
 static inline void list_add(struct list_head *new, struct list_head *head)
 {
 	__list_add(new, head, head->next);
 }
+#else
+extern void list_add(struct list_head *new, struct list_head *head);
+#endif
+
 
 /**
  * list_add_tail - add a new entry
@@ -150,21 +161,25 @@ static inline void __list_del(struct list_head * prev, struct list_head * next)
 /**
  * list_del - deletes entry from list.
  * @entry: the element to delete from the list.
- * Note: list_empty on entry does not return true after this, the entry is
+ * Note: list_empty() on entry does not return true after this, the entry is
  * in an undefined state.
  */
+#ifndef CONFIG_DEBUG_LIST
 static inline void list_del(struct list_head *entry)
 {
 	__list_del(entry->prev, entry->next);
 	entry->next = LIST_POISON1;
 	entry->prev = LIST_POISON2;
 }
+#else
+extern void list_del(struct list_head *entry);
+#endif
 
 /**
  * list_del_rcu - deletes entry from list without re-initialization
  * @entry: the element to delete from the list.
  *
- * Note: list_empty on entry does not return true after this,
+ * Note: list_empty() on entry does not return true after this,
  * the entry is in an undefined state. It is useful for RCU based
  * lockfree traversal.
  *
@@ -194,7 +209,8 @@ static inline void list_del_rcu(struct list_head *entry)
  * list_replace - replace old entry by new one
  * @old : the element to be replaced
  * @new : the new element to insert
- * Note: if 'old' was empty, it will be overwritten.
+ *
+ * If @old was empty, it will be overwritten.
  */
 static inline void list_replace(struct list_head *old,
 				struct list_head *new)
@@ -212,13 +228,13 @@ static inline void list_replace_init(struct list_head *old,
 	INIT_LIST_HEAD(old);
 }
 
-/*
+/**
  * 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.
- * Note: 'old' should not be empty.
+ * The @old entry will be replaced with the @new entry atomically.
+ * Note: @old should not be empty.
  */
 static inline void list_replace_rcu(struct list_head *old,
 				struct list_head *new)
@@ -344,6 +360,62 @@ static inline void list_splice_init(struct list_head *list,
 	}
 }
 
+/**
+ * list_splice_init_rcu - splice an RCU-protected list into an existing list.
+ * @list:	the RCU-protected list to splice
+ * @head:	the place in the list to splice the first list into
+ * @sync:	function to sync: synchronize_rcu(), synchronize_sched(), ...
+ *
+ * @head can be RCU-read traversed concurrently with this function.
+ *
+ * Note that this function blocks.
+ *
+ * Important note: the caller must take whatever action is necessary to
+ *	prevent any other updates to @head.  In principle, it is possible
+ *	to modify the list as soon as sync() begins execution.
+ *	If this sort of thing becomes necessary, an alternative version
+ *	based on call_rcu() could be created.  But only if -really-
+ *	needed -- there is no shortage of RCU API members.
+ */
+static inline void list_splice_init_rcu(struct list_head *list,
+					struct list_head *head,
+					void (*sync)(void))
+{
+	struct list_head *first = list->next;
+	struct list_head *last = list->prev;
+	struct list_head *at = head->next;
+
+	if (list_empty(head))
+		return;
+
+	/* "first" and "last" tracking list, so initialize it. */
+
+	INIT_LIST_HEAD(list);
+
+	/*
+	 * At this point, the list body still points to the source list.
+	 * Wait for any readers to finish using the list before splicing
+	 * the list body into the new list.  Any new readers will see
+	 * an empty list.
+	 */
+
+	sync();
+
+	/*
+	 * Readers are finished with the source list, so perform splice.
+	 * The order is important if the new list is global and accessible
+	 * to concurrent RCU readers.  Note that RCU readers are not
+	 * permitted to traverse the prev pointers without excluding
+	 * this function.
+	 */
+
+	last->next = at;
+	smp_wmb();
+	head->next = first;
+	first->prev = head;
+	at->prev = last;
+}
+
 /**
  * list_entry - get the struct for this entry
  * @ptr:	the &struct list_head pointer.
@@ -417,12 +489,12 @@ static inline void list_splice_init(struct list_head *list,
 	     pos = list_entry(pos->member.prev, typeof(*pos), member))
 
 /**
- * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue
+ * list_prepare_entry - prepare a pos entry for use in list_for_each_entry_continue()
  * @pos:	the type * to use as a start point
  * @head:	the head of the list
  * @member:	the name of the list_struct within the struct.
  *
- * Prepares a pos entry for use as a start point in list_for_each_entry_continue.
+ * Prepares a pos entry for use as a start point in list_for_each_entry_continue().
  */
 #define list_prepare_entry(pos, head, member) \
 	((pos) ? : list_entry(head, typeof(*pos), member))
@@ -665,12 +737,12 @@ static inline void hlist_del_init(struct hlist_node *n)
 	}
 }
 
-/*
+/**
  * hlist_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.
+ * The @old entry will be replaced with the @new entry atomically.
  */
 static inline void hlist_replace_rcu(struct hlist_node *old,
 					struct hlist_node *new)