ipv4: using prefetch requires including prefetch.h

[karo-tx-linux.git] / lib / llist.c

diff --git a/lib/llist.c b/lib/llist.c
index da445724fa1ffe221421b06c540dd17b9e0df2b7..700cff77a3870a04ca050b92b47f1a93c04368e3 100644 (file)
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -3,8 +3,8 @@
  *
  * The basic atomic operation of this list is cmpxchg on long.  On
  * architectures that don't have NMI-safe cmpxchg implementation, the
- * list can NOT be used in NMI handler.  So code uses the list in NMI
- * handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
+ * list can NOT be used in NMI handlers.  So code that uses the list in
+ * an NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
  *
  * Copyright 2010,2011 Intel Corp.
  *   Author: Huang Ying <ying.huang@intel.com>
@@ -29,49 +29,29 @@
 
 #include <asm/system.h>
 
-/**
- * llist_add - add a new entry
- * @new:       new entry to be added
- * @head:      the head for your lock-less list
- */
-void llist_add(struct llist_node *new, struct llist_head *head)
-{
-       struct llist_node *entry, *old_entry;
-
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-       BUG_ON(in_nmi());
-#endif
-
-       entry = head->first;
-       do {
-               old_entry = entry;
-               new->next = entry;
-               cpu_relax();
-       } while ((entry = cmpxchg(&head->first, old_entry, new)) != old_entry);
-}
-EXPORT_SYMBOL_GPL(llist_add);
-
 /**
  * llist_add_batch - add several linked entries in batch
  * @new_first: first entry in batch to be added
  * @new_last:  last entry in batch to be added
  * @head:      the head for your lock-less list
+ *
+ * Return whether list is empty before adding.
  */
-void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
+bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
                     struct llist_head *head)
 {
        struct llist_node *entry, *old_entry;
 
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-       BUG_ON(in_nmi());
-#endif
-
        entry = head->first;
-       do {
+       for (;;) {
                old_entry = entry;
                new_last->next = entry;
-               cpu_relax();
-       } while ((entry = cmpxchg(&head->first, old_entry, new_first)) != old_entry);
+               entry = cmpxchg(&head->first, old_entry, new_first);
+               if (entry == old_entry)
+                       break;
+       }
+
+       return old_entry == NULL;
 }
 EXPORT_SYMBOL_GPL(llist_add_batch);
 
@@ -93,37 +73,17 @@ struct llist_node *llist_del_first(struct llist_head *head)
 {
        struct llist_node *entry, *old_entry, *next;
 
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-       BUG_ON(in_nmi());
-#endif
-
        entry = head->first;
-       do {
+       for (;;) {
                if (entry == NULL)
                        return NULL;
                old_entry = entry;
                next = entry->next;
-               cpu_relax();
-       } while ((entry = cmpxchg(&head->first, old_entry, next)) != old_entry);
+               entry = cmpxchg(&head->first, old_entry, next);
+               if (entry == old_entry)
+                       break;
+       }
 
        return entry;
 }
 EXPORT_SYMBOL_GPL(llist_del_first);
-
-/**
- * llist_del_all - delete all entries from lock-less list
- * @head:      the head of lock-less list to delete all entries
- *
- * If list is empty, return NULL, otherwise, delete all entries and
- * return the pointer to the first entry.  The order of entries
- * deleted is from the newest to the oldest added one.
- */
-struct llist_node *llist_del_all(struct llist_head *head)
-{
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
-       BUG_ON(in_nmi());
-#endif
-
-       return xchg(&head->first, NULL);
-}
-EXPORT_SYMBOL_GPL(llist_del_all);