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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 17:40:19 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-18 17:40:19 +0000
commit9f0fc191371843c4fc000a226b0a26b6c059aacd (patch)
tree35f8be3ef04506ac891ad001e8c41e535ae8d01d /lib/llist.c
parentReleasing progress-linux version 6.6.15-2~progress7.99u1. (diff)
downloadlinux-9f0fc191371843c4fc000a226b0a26b6c059aacd.tar.xz
linux-9f0fc191371843c4fc000a226b0a26b6c059aacd.zip
Merging upstream version 6.7.7.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/llist.c')
-rw-r--r--lib/llist.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/lib/llist.c b/lib/llist.c
index 6e668fa5a2..f21d0cfbba 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -66,6 +66,34 @@ struct llist_node *llist_del_first(struct llist_head *head)
EXPORT_SYMBOL_GPL(llist_del_first);
/**
+ * llist_del_first_this - delete given entry of lock-less list if it is first
+ * @head: the head for your lock-less list
+ * @this: a list entry.
+ *
+ * If head of the list is given entry, delete and return %true else
+ * return %false.
+ *
+ * Multiple callers can safely call this concurrently with multiple
+ * llist_add() callers, providing all the callers offer a different @this.
+ */
+bool llist_del_first_this(struct llist_head *head,
+ struct llist_node *this)
+{
+ struct llist_node *entry, *next;
+
+ /* acquire ensures orderig wrt try_cmpxchg() is llist_del_first() */
+ entry = smp_load_acquire(&head->first);
+ do {
+ if (entry != this)
+ return false;
+ next = READ_ONCE(entry->next);
+ } while (!try_cmpxchg(&head->first, &entry, next));
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(llist_del_first_this);
+
+/**
* llist_reverse_order - reverse order of a llist chain
* @head: first item of the list to be reversed
*