Martin Schwidefsky wrote:
  "s390 does not even need (in|out)b(_p|).  I wondered what else from
   io.h do we not need.  The answer is: almost nothing.  With the devres
   patch from Al and the dma-mapping patch from Heiko we can get rid of
   iomem and all associated definitions."

So we'll just need to replace NO_IOPORT with NO_IOMEM in Kconfig and
kill arch/s390/mm/ioremap.c.

BTW, there's an annoying bit of junk in there - IO_SPACE_LIMIT.  We
only need it for /proc/ioports, which AFAICS shouldn't even be there
on s390 (or uml).  OTOH, removing that thing would mean a user-visible
change - we go from "empty file in /proc" to "no such file in /proc"...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>