Merge branch 'asm-generic-pci-iobase' into asm-generic

Merge branch 'asm-generic-pci-iobase' into asm-generic

A rework for PCI I/O space access from Niklas Schnelle:

  "This is version 5 of my attempt to get rid of a clang
   -Wnull-pointer-arithmetic warning for the use of PCI_IOBASE in
   asm-generic/io.h. This was originally found on s390 but should apply to
   all platforms leaving PCI_IOBASE undefined while making use of the inb()
   and friends helpers from asm-generic/io.h.

   This applies cleanly and was compile tested on top of v5.12 for the
   previously broken ARC, nds32, h8300 and risc-v architecture. It also
   applies cleanly on v5.13-rc1 for which I boot tested it on s390.

   I did boot test this only on x86_64 and s390x the former implements
   inb() itself while the latter would emit a WARN_ONCE() but no drivers
   use inb()."

* asm-generic-pci-iobase:
  asm-generic/io.h: warn in inb() and friends with undefined PCI_IOBASE
  risc-v: Use generic io.h helpers for nommu
  sparc: explicitly set PCI_IOBASE to 0

Link: https://lore.kernel.org/lkml/20210510145234.594814-1-schnelle@linux.ibm.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>