On Tue, Mar 18, 2025 at 10:13:35PM +0100, Arnd Bergmann wrote:

Thanks for the report, I missed that the generic ioport_map() function
is missing the PCI_IOBASE macro, we should probably remove that from
the asm-generic/io.h header and require architectures to define it
themselves, since the NULL fallback is pretty much always wrong.

There is also a type mismatch between the MIPS
PCI_IOBASE/mips_io_port_base and the one that asm-generic/io.h
expects, so I had to add a couple of extra typecasts, which
makes it rather ugly, but the change below seems to work.

Thanks, that does make the -Wnull-pointer-arithmetic warnings disappear.
That build still fails in next-20250319 (which includes that change) at
the end with:

  $ make -skj"$(nproc)" ARCH=mips CROSS_COMPILE=mips-linux- mrproper malta_defconfig all
  ERROR: modpost: "pci_iounmap" [drivers/net/wireless/intel/ipw2x00/ipw2100.ko] undefined!

which appears related to this original change.

Cheers,
Nathan