[tip: locking/core] llist: simplify __llist_del_all

[tip-bot2 for Andrzej Hajda]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     ce27b24cbf7f62b74c4cbf807a06f42a14ccf981
Gitweb:        https://git.kernel.org/tip/ce27b24cbf7f62b74c4cbf807a06f42a14ccf981
Author:        Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
AuthorDate:    Wed, 18 Jan 2023 16:44:47 +01:00
Committer:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Sat, 11 Mar 2023 14:03:59 +01:00

llist: simplify __llist_del_all

llist_del_all uses xchg, let's use __xchg here.

Signed-off-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230118154450.73842-4-andrzej.hajda@xxxxxxxxx
---
 include/linux/llist.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/include/linux/llist.h b/include/linux/llist.h
index 85bda2d..4dc1d18 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -50,6 +50,7 @@
 
 #include <linux/atomic.h>
 #include <linux/container_of.h>
+#include <linux/non-atomic/xchg.h>
 #include <linux/stddef.h>
 #include <linux/types.h>
 
@@ -241,10 +242,7 @@ static inline struct llist_node *llist_del_all(struct llist_head *head)
 
 static inline struct llist_node *__llist_del_all(struct llist_head *head)
 {
-	struct llist_node *first = head->first;
-
-	head->first = NULL;
-	return first;
+	return __xchg(&head->first, NULL);
 }
 
 extern struct llist_node *llist_del_first(struct llist_head *head);