nds32: Use asm-generic/io.h

Convert the nds32 architecture to make use of the new asm-generic/io.h
to provide address mapping functions. As the generic implementations are
suitable for nds32 this is primarily a matter of removing code.

Feedback from architecture maintainers is welcome.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Macpaul Lin <macpaul@andestech.com>

arch/nds32/include/asm/io.h

@@ -38,16 +38,6 @@ static inline void sync(void)
 {
 }
 
-/*
- * Given a physical address and a length, return a virtual address
- * that can be used to access the memory range with the caching
- * properties specified by "flags".
- */
-#define MAP_NOCACHE	(0)
-#define MAP_WRCOMBINE	(0)
-#define MAP_WRBACK	(0)
-#define MAP_WRTHROUGH	(0)
-
 #ifdef CONFIG_ARCH_MAP_SYSMEM
 static inline void *map_sysmem(phys_addr_t paddr, unsigned long len)
 {
@@ -69,25 +59,6 @@ static inline phys_addr_t map_to_sysmem(const void *ptr)
 }
 #endif
 
-static inline void *
-map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
-{
-	return (void *)paddr;
-}
-
-/*
- * Take down a mapping set up by map_physmem().
- */
-static inline void unmap_physmem(void *vaddr, unsigned long flags)
-{
-
-}
-
-static inline phys_addr_t virt_to_phys(void *vaddr)
-{
-	return (phys_addr_t)(vaddr);
-}
-
 /*
  * Generic virtual read/write.  Note that we don't support half-word
  * read/writes.  We define __arch_*[bl] here, and leave __arch_*w
@@ -480,5 +451,8 @@ out:
 #define isa_check_signature(io, sig, len)	(0)
 
 #endif	/* __mem_isa */
+
+#include <asm-generic/io.h>
+
 #endif	/* __KERNEL__ */
 #endif	/* __ASM_NDS_IO_H */