nios2: fix map_physmem to do real cache mapping

Fix the map_physmem() to do real cache mapping.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Marek Vasut <marex@denx.de>

arch/nios2/cpu/cpu.c

@@ -117,7 +117,8 @@ static int altera_nios2_probe(struct udevice *dev)
 		"altr,has-initda", 0);
 	gd->arch.has_mmu = fdtdec_get_int(blob, node,
 		"altr,has-mmu", 0);
-	gd->arch.io_region_base = gd->arch.has_mmu ? 0xe0000000 : 0x8000000;
+	gd->arch.io_region_base = gd->arch.has_mmu ? 0xe0000000 : 0x80000000;
+	gd->arch.mem_region_base = gd->arch.has_mmu ? 0xc0000000 : 0x00000000;
 
 	return 0;
 }

arch/nios2/include/asm/global_data.h

@@ -18,6 +18,7 @@ struct arch_global_data {
 	int has_initda;
 	int has_mmu;
 	u32 io_region_base;
+	u32 mem_region_base;
 };
 
 #include <asm-generic/global_data.h>

arch/nios2/include/asm/io.h

@@ -18,7 +18,7 @@ static inline void sync(void)
  * that can be used to access the memory range with the caching
  * properties specified by "flags".
  */
-#define MAP_NOCACHE	(0)
+#define MAP_NOCACHE	(1)
 #define MAP_WRCOMBINE	(0)
 #define MAP_WRBACK	(0)
 #define MAP_WRTHROUGH	(0)
@@ -26,7 +26,11 @@ static inline void sync(void)
 static inline void *
 map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
 {
-	return (void *)paddr;
+	DECLARE_GLOBAL_DATA_PTR;
+	if (flags)
+		return (void *)(paddr | gd->arch.io_region_base);
+	else
+		return (void *)(paddr | gd->arch.mem_region_base);
 }
 
 /*