1 files changed, 70 insertions, 0 deletions

diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..f6bd1406b897
--- /dev/null
+++ b/arch/sh/include/asm/cmpxchg.h
@@ -0,0 +1,70 @@
+#ifndef __ASM_SH_CMPXCHG_H
+#define __ASM_SH_CMPXCHG_H
+
+/*
+ * Atomic operations that C can't guarantee us.  Useful for
+ * resource counting etc..
+ */
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+#if defined(CONFIG_GUSA_RB)
+#include <asm/cmpxchg-grb.h>
+#elif defined(CONFIG_CPU_SH4A)
+#include <asm/cmpxchg-llsc.h>
+#else
+#include <asm/cmpxchg-irq.h>
+#endif
+
+extern void __xchg_called_with_bad_pointer(void);
+
+#define __xchg(ptr, x, size)                            \
+({                                                      \
+        unsigned long __xchg__res;                      \
+        volatile void *__xchg_ptr = (ptr);              \
+        switch (size) {                                 \
+        case 4:                                         \
+                __xchg__res = xchg_u32(__xchg_ptr, x);  \
+                break;                                  \
+        case 1:                                         \
+                __xchg__res = xchg_u8(__xchg_ptr, x);   \
+                break;                                  \
+        default:                                        \
+                __xchg_called_with_bad_pointer();       \
+                __xchg__res = x;                        \
+                break;                                  \
+        }                                               \
+                                                        \
+        __xchg__res;                                    \
+})
+
+#define xchg(ptr,x)     \
+        ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
+
+/* 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);
+        }
+        __cmpxchg_called_with_bad_pointer();
+        return old;
+}
+
+#define cmpxchg(ptr,o,n)                                                 \
+  ({                                                                     \
+     __typeof__(*(ptr)) _o_ = (o);                                       \
+     __typeof__(*(ptr)) _n_ = (n);                                       \
+     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
+                                    (unsigned long)_n_, sizeof(*(ptr))); \
+  })
+
+#endif /* __ASM_SH_CMPXCHG_H */