ARM: cpu: Add ARMv7 barrier operations support

This enables ARMv7 barrier operations support when
march=armv7-a is enabled.

Using CP15 barriers causes U-Boot bootm command crash when
transferring control to the loaded image on Renesas R8A7794 Cortex A7 CPU.
Using ARMv7 barrier operations instead of the deprecated CP15 barriers
helps to avoid these issues.

Signed-off-by: Valentine Barshak <valentine.barshak+renesas@cogentembedded.com>
Signed-off-by: Vladimir Barinov <vladimir.barinov+renesas@cogentembedded.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h
index 58d8b16..cbe7dc1 100644
--- a/arch/arm/include/asm/armv7.h
+++ b/arch/arm/include/asm/armv7.h
@@ -70,6 +70,16 @@
 #define CP15DSB	asm volatile ("mcr     p15, 0, %0, c7, c10, 4" : : "r" (0))
 #define CP15DMB	asm volatile ("mcr     p15, 0, %0, c7, c10, 5" : : "r" (0))
 
+#ifdef __ARM_ARCH_7A__
+#define ISB	asm volatile ("isb" : : : "memory")
+#define DSB	asm volatile ("dsb" : : : "memory")
+#define DMB	asm volatile ("dmb" : : : "memory")
+#else
+#define ISB	CP15ISB
+#define DSB	CP15DSB
+#define DMB	CP15DMB
+#endif
+
 /*
  * Workaround for ARM errata # 798870
  * Set L2ACTLR[7] to reissue any memory transaction in the L2 that has been