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-rw-r--r--lib/locks/exclusive/aarch32/spinlock.S31
1 files changed, 31 insertions, 0 deletions
diff --git a/lib/locks/exclusive/aarch32/spinlock.S b/lib/locks/exclusive/aarch32/spinlock.S
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+++ b/lib/locks/exclusive/aarch32/spinlock.S
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+
+ .globl spin_lock
+ .globl spin_unlock
+
+
+func spin_lock
+ mov r2, #1
+1:
+ ldrex r1, [r0]
+ cmp r1, #0
+ wfene
+ strexeq r1, r2, [r0]
+ cmpeq r1, #0
+ bne 1b
+ dmb
+ bx lr
+endfunc spin_lock
+
+
+func spin_unlock
+ mov r1, #0
+ stl r1, [r0]
+ bx lr
+endfunc spin_unlock