1 files changed, 61 insertions, 0 deletions
diff --git a/arch/nios2/include/asm/cmpxchg.h b/arch/nios2/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..85938711542d
--- /dev/null
+++ b/arch/nios2/include/asm/cmpxchg.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2004 Microtronix Datacom Ltd.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#ifndef _ASM_NIOS2_CMPXCHG_H
+#define _ASM_NIOS2_CMPXCHG_H
+
+#include <linux/irqflags.h>
+
+#define xchg(ptr, x)	\
+	((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
+
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x)		((volatile struct __xchg_dummy *)(x))
+
+static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
+					int size)
+{
+	unsigned long tmp, flags;
+
+	local_irq_save(flags);
+
+	switch (size) {
+	case 1:
+		__asm__ __volatile__(
+			"ldb	%0, %2\n"
+			"stb	%1, %2\n"
+			: "=&r" (tmp)
+			: "r" (x), "m" (*__xg(ptr))
+			: "memory");
+		break;
+	case 2:
+		__asm__ __volatile__(
+			"ldh	%0, %2\n"
+			"sth	%1, %2\n"
+			: "=&r" (tmp)
+			: "r" (x), "m" (*__xg(ptr))
+			: "memory");
+		break;
+	case 4:
+		__asm__ __volatile__(
+			"ldw	%0, %2\n"
+			"stw	%1, %2\n"
+			: "=&r" (tmp)
+			: "r" (x), "m" (*__xg(ptr))
+			: "memory");
+		break;
+	}
+
+	local_irq_restore(flags);
+	return tmp;
+}
+
+#include <asm-generic/cmpxchg.h>
+#include <asm-generic/cmpxchg-local.h>
+
+#endif /* _ASM_NIOS2_CMPXCHG_H */