--- zzzz-none-000/linux-3.10.107/arch/mips/include/asm/mach-generic/spaces.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/mips/include/asm/mach-generic/spaces.h	2021-02-04 17:41:59.000000000 +0000
@@ -25,8 +25,12 @@
 #else
 #define CAC_BASE		_AC(0x80000000, UL)
 #endif
+#ifndef IO_BASE
 #define IO_BASE			_AC(0xa0000000, UL)
+#endif
+#ifndef UNCAC_BASE
 #define UNCAC_BASE		_AC(0xa0000000, UL)
+#endif
 
 #ifndef MAP_BASE
 #ifdef CONFIG_KVM_GUEST
@@ -40,7 +44,7 @@
  * Memory above this physical address will be considered highmem.
  */
 #ifndef HIGHMEM_START
-#define HIGHMEM_START		_AC(0x20000000, UL)
+#define HIGHMEM_START		_AC(0x10000000, UL)
 #endif
 
 #endif /* CONFIG_32BIT */