From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 arch/unicore32/include/asm/cmpxchg.h | 61 ++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 arch/unicore32/include/asm/cmpxchg.h

(limited to 'arch/unicore32/include/asm/cmpxchg.h')

diff --git a/arch/unicore32/include/asm/cmpxchg.h b/arch/unicore32/include/asm/cmpxchg.h
new file mode 100644
index 00000000..8e797ad4
--- /dev/null
+++ b/arch/unicore32/include/asm/cmpxchg.h
@@ -0,0 +1,61 @@
+/*
+ * Atomics xchg/cmpxchg for PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2012 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __UNICORE_CMPXCHG_H__
+#define __UNICORE_CMPXCHG_H__
+
+/*
+ * Generate a link failure on undefined symbol if the pointer points to a value
+ * of unsupported size.
+ */
+extern void __xchg_bad_pointer(void);
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+		int size)
+{
+	unsigned long ret;
+
+	switch (size) {
+	case 1:
+		asm volatile("swapb	%0, %1, [%2]"
+			: "=&r" (ret)
+			: "r" (x), "r" (ptr)
+			: "memory", "cc");
+		break;
+	case 4:
+		asm volatile("swapw	%0, %1, [%2]"
+			: "=&r" (ret)
+			: "r" (x), "r" (ptr)
+			: "memory", "cc");
+		break;
+	default:
+		__xchg_bad_pointer();
+	}
+
+	return ret;
+}
+
+#define xchg(ptr, x) \
+	((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
+
+#include <asm-generic/cmpxchg-local.h>
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n)					\
+		((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr),	\
+		(unsigned long)(o), (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n)					\
+		__cmpxchg64_local_generic((ptr), (o), (n))
+
+#include <asm-generic/cmpxchg.h>
+
+#endif /* __UNICORE_CMPXCHG_H__ */
-- 
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