1 files changed, 145 insertions, 0 deletions

diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h
new file mode 100644
index 00000000000..b30eb37294c
--- /dev/null
+++ b/arch/sparc/include/asm/cmpxchg_64.h
@@ -0,0 +1,145 @@
+/* 64-bit atomic xchg() and cmpxchg() definitions.
+ *
+ * Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
+ */
+
+#ifndef __ARCH_SPARC64_CMPXCHG__
+#define __ARCH_SPARC64_CMPXCHG__
+
+static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
+{
+        unsigned long tmp1, tmp2;
+
+        __asm__ __volatile__(
+"       mov             %0, %1\n"
+"1:     lduw            [%4], %2\n"
+"       cas             [%4], %2, %0\n"
+"       cmp             %2, %0\n"
+"       bne,a,pn        %%icc, 1b\n"
+"        mov            %1, %0\n"
+        : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
+        : "0" (val), "r" (m)
+        : "cc", "memory");
+        return val;
+}
+
+static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
+{
+        unsigned long tmp1, tmp2;
+
+        __asm__ __volatile__(
+"       mov             %0, %1\n"
+"1:     ldx             [%4], %2\n"
+"       casx            [%4], %2, %0\n"
+"       cmp             %2, %0\n"
+"       bne,a,pn        %%xcc, 1b\n"
+"        mov            %1, %0\n"
+        : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
+        : "0" (val), "r" (m)
+        : "cc", "memory");
+        return val;
+}
+
+#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(unsigned long x, __volatile__ void * ptr,
+                                       int size)
+{
+        switch (size) {
+        case 4:
+                return xchg32(ptr, x);
+        case 8:
+                return xchg64(ptr, x);
+        }
+        __xchg_called_with_bad_pointer();
+        return x;
+}
+
+/*
+ * Atomic compare and exchange.  Compare OLD with MEM, if identical,
+ * store NEW in MEM.  Return the initial value in MEM.  Success is
+ * indicated by comparing RETURN with OLD.
+ */
+
+#include <asm-generic/cmpxchg-local.h>
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+static inline unsigned long
+__cmpxchg_u32(volatile int *m, int old, int new)
+{
+        __asm__ __volatile__("cas [%2], %3, %0"
+                             : "=&r" (new)
+                             : "0" (new), "r" (m), "r" (old)
+                             : "memory");
+
+        return new;
+}
+
+static inline unsigned long
+__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
+{
+        __asm__ __volatile__("casx [%2], %3, %0"
+                             : "=&r" (new)
+                             : "0" (new), "r" (m), "r" (old)
+                             : "memory");
+
+        return new;
+}
+
+/* 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);
+
+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,o,n)                                                 \
+  ({                                                                     \
+     __typeof__(*(ptr)) _o_ = (o);                                       \
+     __typeof__(*(ptr)) _n_ = (n);                                       \
+     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
+                                    (unsigned long)_n_, sizeof(*(ptr))); \
+  })
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+                                      unsigned long old,
+                                      unsigned long new, int size)
+{
+        switch (size) {
+        case 4:
+        case 8: return __cmpxchg(ptr, old, new, size);
+        default:
+                return __cmpxchg_local_generic(ptr, old, new, size);
+        }
+
+        return old;
+}
+
+#define cmpxchg_local(ptr, o, n)                                        \
+        ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
+                        (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n)                                      \
+  ({                                                                    \
+        BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
+        cmpxchg_local((ptr), (o), (n));                                 \
+  })
+
+#endif /* __ARCH_SPARC64_CMPXCHG__ */