* 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)
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
* 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
/**
* 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.
*
* 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)
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)
}
}
+/**
+ * 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.
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))
}
}
-/*
+/**
* 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)
projects / linux-drm-fsl-dcu.git / blobdiff