--- zzzz-none-000/linux-3.10.107/arch/tile/include/asm/cmpxchg.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/tile/include/asm/cmpxchg.h	2021-02-04 17:41:59.000000000 +0000
@@ -20,53 +20,114 @@
 
 #ifndef __ASSEMBLY__
 
-/* Nonexistent functions intended to cause link errors. */
-extern unsigned long __xchg_called_with_bad_pointer(void);
-extern unsigned long __cmpxchg_called_with_bad_pointer(void);
+#include <asm/barrier.h>
 
-#define xchg(ptr, x)							\
+/* Nonexistent functions intended to cause compile errors. */
+extern void __xchg_called_with_bad_pointer(void)
+	__compiletime_error("Bad argument size for xchg");
+extern void __cmpxchg_called_with_bad_pointer(void)
+	__compiletime_error("Bad argument size for cmpxchg");
+
+#ifndef __tilegx__
+
+/* Note the _atomic_xxx() routines include a final mb(). */
+int _atomic_xchg(int *ptr, int n);
+int _atomic_xchg_add(int *v, int i);
+int _atomic_xchg_add_unless(int *v, int a, int u);
+int _atomic_cmpxchg(int *ptr, int o, int n);
+long long _atomic64_xchg(long long *v, long long n);
+long long _atomic64_xchg_add(long long *v, long long i);
+long long _atomic64_xchg_add_unless(long long *v, long long a, long long u);
+long long _atomic64_cmpxchg(long long *v, long long o, long long n);
+
+#define xchg(ptr, n)							\
+	({								\
+		if (sizeof(*(ptr)) != 4)				\
+			__xchg_called_with_bad_pointer();		\
+		smp_mb();						\
+		(typeof(*(ptr)))_atomic_xchg((int *)(ptr), (int)(n));	\
+	})
+
+#define cmpxchg(ptr, o, n)						\
+	({								\
+		if (sizeof(*(ptr)) != 4)				\
+			__cmpxchg_called_with_bad_pointer();		\
+		smp_mb();						\
+		(typeof(*(ptr)))_atomic_cmpxchg((int *)ptr, (int)o,	\
+						(int)n);		\
+	})
+
+#define xchg64(ptr, n)							\
+	({								\
+		if (sizeof(*(ptr)) != 8)				\
+			__xchg_called_with_bad_pointer();		\
+		smp_mb();						\
+		(typeof(*(ptr)))_atomic64_xchg((long long *)(ptr),	\
+						(long long)(n));	\
+	})
+
+#define cmpxchg64(ptr, o, n)						\
+	({								\
+		if (sizeof(*(ptr)) != 8)				\
+			__cmpxchg_called_with_bad_pointer();		\
+		smp_mb();						\
+		(typeof(*(ptr)))_atomic64_cmpxchg((long long *)ptr,	\
+					(long long)o, (long long)n);	\
+	})
+
+#else
+
+#define xchg(ptr, n)							\
 	({								\
 		typeof(*(ptr)) __x;					\
+		smp_mb();						\
 		switch (sizeof(*(ptr))) {				\
 		case 4:							\
-			__x = (typeof(__x))(typeof(__x-__x))atomic_xchg( \
-				(atomic_t *)(ptr),			\
-				(u32)(typeof((x)-(x)))(x));		\
+			__x = (typeof(__x))(unsigned long)		\
+				__insn_exch4((ptr),			\
+					(u32)(unsigned long)(n));	\
 			break;						\
 		case 8:							\
-			__x = (typeof(__x))(typeof(__x-__x))atomic64_xchg( \
-				(atomic64_t *)(ptr),			\
-				(u64)(typeof((x)-(x)))(x));		\
+			__x = (typeof(__x))				\
+				__insn_exch((ptr), (unsigned long)(n));	\
 			break;						\
 		default:						\
 			__xchg_called_with_bad_pointer();		\
+			break;						\
 		}							\
+		smp_mb();						\
 		__x;							\
 	})
 
 #define cmpxchg(ptr, o, n)						\
 	({								\
 		typeof(*(ptr)) __x;					\
+		__insn_mtspr(SPR_CMPEXCH_VALUE, (unsigned long)(o));	\
+		smp_mb();						\
 		switch (sizeof(*(ptr))) {				\
 		case 4:							\
-			__x = (typeof(__x))(typeof(__x-__x))atomic_cmpxchg( \
-				(atomic_t *)(ptr),			\
-				(u32)(typeof((o)-(o)))(o),		\
-				(u32)(typeof((n)-(n)))(n));		\
+			__x = (typeof(__x))(unsigned long)		\
+				__insn_cmpexch4((ptr),			\
+					(u32)(unsigned long)(n));	\
 			break;						\
 		case 8:							\
-			__x = (typeof(__x))(typeof(__x-__x))atomic64_cmpxchg( \
-				(atomic64_t *)(ptr),			\
-				(u64)(typeof((o)-(o)))(o),		\
-				(u64)(typeof((n)-(n)))(n));		\
+			__x = (typeof(__x))__insn_cmpexch((ptr),	\
+						(long long)(n));	\
 			break;						\
 		default:						\
 			__cmpxchg_called_with_bad_pointer();		\
+			break;						\
 		}							\
+		smp_mb();						\
 		__x;							\
 	})
 
-#define tas(ptr) (xchg((ptr), 1))
+#define xchg64 xchg
+#define cmpxchg64 cmpxchg
+
+#endif
+
+#define tas(ptr) xchg((ptr), 1)
 
 #endif /* __ASSEMBLY__ */