1 files changed, 115 insertions, 0 deletions
diff --git a/kernel/arch/mn10300/include/asm/cmpxchg.h b/kernel/arch/mn10300/include/asm/cmpxchg.h
new file mode 100644
index 000000000..97a4aaf38
--- /dev/null
+++ b/kernel/arch/mn10300/include/asm/cmpxchg.h
@@ -0,0 +1,115 @@
+/* MN10300 Atomic xchg/cmpxchg operations
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#ifndef _ASM_CMPXCHG_H
+#define _ASM_CMPXCHG_H
+
+#include <asm/irqflags.h>
+
+#ifdef CONFIG_SMP
+#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
+static inline
+unsigned long __xchg(volatile unsigned long *m, unsigned long val)
+{
+	unsigned long status;
+	unsigned long oldval;
+
+	asm volatile(
+		"1:	mov	%4,(_AAR,%3)	\n"
+		"	mov	(_ADR,%3),%1	\n"
+		"	mov	%5,(_ADR,%3)	\n"
+		"	mov	(_ADR,%3),%0	\n"	/* flush */
+		"	mov	(_ASR,%3),%0	\n"
+		"	or	%0,%0		\n"
+		"	bne	1b		\n"
+		: "=&r"(status), "=&r"(oldval), "=m"(*m)
+		: "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), "r"(val)
+		: "memory", "cc");
+
+	return oldval;
+}
+
+static inline unsigned long __cmpxchg(volatile unsigned long *m,
+				      unsigned long old, unsigned long new)
+{
+	unsigned long status;
+	unsigned long oldval;
+
+	asm volatile(
+		"1:	mov	%4,(_AAR,%3)	\n"
+		"	mov	(_ADR,%3),%1	\n"
+		"	cmp	%5,%1		\n"
+		"	bne	2f		\n"
+		"	mov	%6,(_ADR,%3)	\n"
+		"2:	mov	(_ADR,%3),%0	\n"	/* flush */
+		"	mov	(_ASR,%3),%0	\n"
+		"	or	%0,%0		\n"
+		"	bne	1b		\n"
+		: "=&r"(status), "=&r"(oldval), "=m"(*m)
+		: "a"(ATOMIC_OPS_BASE_ADDR), "r"(m),
+		  "r"(old), "r"(new)
+		: "memory", "cc");
+
+	return oldval;
+}
+#else  /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */
+#error "No SMP atomic operation support!"
+#endif /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */
+
+#else  /* CONFIG_SMP */
+
+/*
+ * Emulate xchg for non-SMP MN10300
+ */
+struct __xchg_dummy { unsigned long a[100]; };
+#define __xg(x) ((struct __xchg_dummy *)(x))
+
+static inline
+unsigned long __xchg(volatile unsigned long *m, unsigned long val)
+{
+	unsigned long oldval;
+	unsigned long flags;
+
+	flags = arch_local_cli_save();
+	oldval = *m;
+	*m = val;
+	arch_local_irq_restore(flags);
+	return oldval;
+}
+
+/*
+ * Emulate cmpxchg for non-SMP MN10300
+ */
+static inline unsigned long __cmpxchg(volatile unsigned long *m,
+				      unsigned long old, unsigned long new)
+{
+	unsigned long oldval;
+	unsigned long flags;
+
+	flags = arch_local_cli_save();
+	oldval = *m;
+	if (oldval == old)
+		*m = new;
+	arch_local_irq_restore(flags);
+	return oldval;
+}
+
+#endif /* CONFIG_SMP */
+
+#define xchg(ptr, v)						\
+	((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr),	\
+				     (unsigned long)(v)))
+
+#define cmpxchg(ptr, o, n)					\
+	((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \
+					(unsigned long)(o),	\
+					(unsigned long)(n)))
+
+#endif /* _ASM_CMPXCHG_H */