1 files changed, 117 insertions, 0 deletions
diff --git a/arch/avr32/include/asm/cmpxchg.h b/arch/avr32/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..962a6aeab787
--- /dev/null
+++ b/arch/avr32/include/asm/cmpxchg.h
@@ -0,0 +1,117 @@
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc.
+ *
+ * But use these as seldom as possible since they are slower than
+ * regular operations.
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * 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 __ASM_AVR32_CMPXCHG_H
+#define __ASM_AVR32_CMPXCHG_H
+
+#define xchg(ptr,x) \
+	((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+extern void __xchg_called_with_bad_pointer(void);
+
+static inline unsigned long xchg_u32(u32 val, volatile u32 *m)
+{
+	u32 ret;
+
+	asm volatile("xchg %[ret], %[m], %[val]"
+			: [ret] "=&r"(ret), "=m"(*m)
+			: "m"(*m), [m] "r"(m), [val] "r"(val)
+			: "memory");
+	return ret;
+}
+
+static inline unsigned long __xchg(unsigned long x,
+				       volatile void *ptr,
+				       int size)
+{
+	switch(size) {
+	case 4:
+		return xchg_u32(x, ptr);
+	default:
+		__xchg_called_with_bad_pointer();
+		return x;
+	}
+}
+
+static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
+					  unsigned long new)
+{
+	__u32 ret;
+
+	asm volatile(
+		"1:	ssrf	5\n"
+		"	ld.w	%[ret], %[m]\n"
+		"	cp.w	%[ret], %[old]\n"
+		"	brne	2f\n"
+		"	stcond	%[m], %[new]\n"
+		"	brne	1b\n"
+		"2:\n"
+		: [ret] "=&r"(ret), [m] "=m"(*m)
+		: "m"(m), [old] "ir"(old), [new] "r"(new)
+		: "memory", "cc");
+	return ret;
+}
+
+extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
+        volatile int * m, unsigned long old, unsigned long new);
+#define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
+
+/* This function doesn't exist, so you'll get a linker error
+   if something tries to do an invalid cmpxchg().  */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
+				      unsigned long new, int size)
+{
+	switch (size) {
+	case 4:
+		return __cmpxchg_u32(ptr, old, new);
+	case 8:
+		return __cmpxchg_u64(ptr, old, new);
+	}
+
+	__cmpxchg_called_with_bad_pointer();
+	return old;
+}
+
+#define cmpxchg(ptr, old, new)					\
+	((typeof(*(ptr)))__cmpxchg((ptr), (unsigned long)(old),	\
+				   (unsigned long)(new),	\
+				   sizeof(*(ptr))))
+
+#include <asm-generic/cmpxchg-local.h>
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+				      unsigned long old,
+				      unsigned long new, int size)
+{
+	switch (size) {
+	case 4:
+		return __cmpxchg_u32(ptr, old, new);
+	default:
+		return __cmpxchg_local_generic(ptr, old, new, size);
+	}
+
+	return old;
+}
+
+#define cmpxchg_local(ptr, old, new)					\
+	((typeof(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(old),	\
+				   (unsigned long)(new),		\
+				   sizeof(*(ptr))))
+
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+
+#endif /* __ASM_AVR32_CMPXCHG_H */