Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/asm-generic/qrwlock.h b/include/asm-generic/qrwlock.h
index 0f7062b..3aefde2 100644
--- a/include/asm-generic/qrwlock.h
+++ b/include/asm-generic/qrwlock.h
@@ -1,16 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Queue read/write lock
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
* (C) Copyright 2013-2014 Hewlett-Packard Development Company, L.P.
*
* Authors: Waiman Long <waiman.long@hp.com>
@@ -71,8 +62,8 @@
if (unlikely(cnts))
return 0;
- return likely(atomic_cmpxchg_acquire(&lock->cnts,
- cnts, cnts | _QW_LOCKED) == cnts);
+ return likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts,
+ _QW_LOCKED));
}
/**
* queued_read_lock - acquire read lock of a queue rwlock
@@ -96,8 +87,9 @@
*/
static inline void queued_write_lock(struct qrwlock *lock)
{
+ u32 cnts = 0;
/* Optimize for the unfair lock case where the fair flag is 0. */
- if (atomic_cmpxchg_acquire(&lock->cnts, 0, _QW_LOCKED) == 0)
+ if (likely(atomic_try_cmpxchg_acquire(&lock->cnts, &cnts, _QW_LOCKED)))
return;
queued_write_lock_slowpath(lock);