v4.19.13 snapshot.
diff --git a/arch/nds32/mm/ioremap.c b/arch/nds32/mm/ioremap.c
new file mode 100644
index 0000000..690140b
--- /dev/null
+++ b/arch/nds32/mm/ioremap.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/vmalloc.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <asm/pgtable.h>
+
+void __iomem *ioremap(phys_addr_t phys_addr, size_t size);
+
+static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
+ void *caller)
+{
+ struct vm_struct *area;
+ unsigned long addr, offset, last_addr;
+ pgprot_t prot;
+
+ /* Don't allow wraparound or zero size */
+ last_addr = phys_addr + size - 1;
+ if (!size || last_addr < phys_addr)
+ return NULL;
+
+ /*
+ * Mappings have to be page-aligned
+ */
+ offset = phys_addr & ~PAGE_MASK;
+ phys_addr &= PAGE_MASK;
+ size = PAGE_ALIGN(last_addr + 1) - phys_addr;
+
+ /*
+ * Ok, go for it..
+ */
+ area = get_vm_area_caller(size, VM_IOREMAP, caller);
+ if (!area)
+ return NULL;
+
+ area->phys_addr = phys_addr;
+ addr = (unsigned long)area->addr;
+ prot = __pgprot(_PAGE_V | _PAGE_M_KRW | _PAGE_D |
+ _PAGE_G | _PAGE_C_DEV);
+ if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
+ vunmap((void *)addr);
+ return NULL;
+ }
+ return (__force void __iomem *)(offset + (char *)addr);
+
+}
+
+void __iomem *ioremap(phys_addr_t phys_addr, size_t size)
+{
+ return __ioremap_caller(phys_addr, size,
+ __builtin_return_address(0));
+}
+
+EXPORT_SYMBOL(ioremap);
+
+void iounmap(volatile void __iomem * addr)
+{
+ vunmap((void *)(PAGE_MASK & (unsigned long)addr));
+}
+
+EXPORT_SYMBOL(iounmap);