--- zzzz-none-000/linux-3.10.107/include/asm-generic/barrier.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/include/asm-generic/barrier.h	2021-02-04 17:41:59.000000000 +0000
@@ -1,4 +1,5 @@
-/* Generic barrier definitions, based on MN10300 definitions.
+/*
+ * Generic barrier definitions, originally based on MN10300 definitions.
  *
  * It should be possible to use these on really simple architectures,
  * but it serves more as a starting point for new ports.
@@ -16,35 +17,107 @@
 
 #ifndef __ASSEMBLY__
 
-#define nop() asm volatile ("nop")
+#include <linux/compiler.h>
+
+#ifndef nop
+#define nop()	asm volatile ("nop")
+#endif
 
 /*
- * Force strict CPU ordering.
- * And yes, this is required on UP too when we're talking
- * to devices.
+ * Force strict CPU ordering. And yes, this is required on UP too when we're
+ * talking to devices.
  *
- * This implementation only contains a compiler barrier.
+ * Fall back to compiler barriers if nothing better is provided.
  */
 
-#define mb()	asm volatile ("": : :"memory")
+#ifndef mb
+#define mb()	barrier()
+#endif
+
+#ifndef rmb
 #define rmb()	mb()
-#define wmb()	asm volatile ("": : :"memory")
+#endif
+
+#ifndef wmb
+#define wmb()	mb()
+#endif
+
+#ifndef dma_rmb
+#define dma_rmb()	rmb()
+#endif
+
+#ifndef dma_wmb
+#define dma_wmb()	wmb()
+#endif
+
+#ifndef read_barrier_depends
+#define read_barrier_depends()		do { } while (0)
+#endif
 
 #ifdef CONFIG_SMP
+
+#ifndef smp_mb
 #define smp_mb()	mb()
+#endif
+
+#ifndef smp_rmb
 #define smp_rmb()	rmb()
+#endif
+
+#ifndef smp_wmb
 #define smp_wmb()	wmb()
-#else
+#endif
+
+#ifndef smp_read_barrier_depends
+#define smp_read_barrier_depends()	read_barrier_depends()
+#endif
+
+#else	/* !CONFIG_SMP */
+
+#ifndef smp_mb
 #define smp_mb()	barrier()
+#endif
+
+#ifndef smp_rmb
 #define smp_rmb()	barrier()
+#endif
+
+#ifndef smp_wmb
 #define smp_wmb()	barrier()
 #endif
 
-#define set_mb(var, value)  do { var = value;  mb(); } while (0)
-#define set_wmb(var, value) do { var = value; wmb(); } while (0)
+#ifndef smp_read_barrier_depends
+#define smp_read_barrier_depends()	do { } while (0)
+#endif
+
+#endif	/* CONFIG_SMP */
+
+#ifndef smp_store_mb
+#define smp_store_mb(var, value)  do { WRITE_ONCE(var, value); mb(); } while (0)
+#endif
+
+#ifndef smp_mb__before_atomic
+#define smp_mb__before_atomic()	smp_mb()
+#endif
+
+#ifndef smp_mb__after_atomic
+#define smp_mb__after_atomic()	smp_mb()
+#endif
 
-#define read_barrier_depends()		do {} while (0)
-#define smp_read_barrier_depends()	do {} while (0)
+#define smp_store_release(p, v)						\
+do {									\
+	compiletime_assert_atomic_type(*p);				\
+	smp_mb();							\
+	WRITE_ONCE(*p, v);						\
+} while (0)
+
+#define smp_load_acquire(p)						\
+({									\
+	typeof(*p) ___p1 = READ_ONCE(*p);				\
+	compiletime_assert_atomic_type(*p);				\
+	smp_mb();							\
+	___p1;								\
+})
 
 #endif /* !__ASSEMBLY__ */
 #endif /* __ASM_GENERIC_BARRIER_H */