On Mon, Oct 2, 2023, at 16:57, Frank Li wrote: > ld: fs/debugfs/file.o: in function `debugfs_print_regs': > file.c:(.text+0x95a): undefined reference to `ioread64be' >>> ld: file.c:(.text+0x9dd): undefined reference to `ioread64' > > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Closes: > https://lore.kernel.org/oe-kbuild-all/202309291322.3pZiyosI-lkp@xxxxxxxxx/ > Signed-off-by: Frank Li <Frank.Li@xxxxxxx> > --- I still think this is wrong, for the reasons I explained in https://lore.kernel.org/all/b795ed61-0174-487f-a263-8431e7c76af5@xxxxxxxxxxxxxxxx/ The part that I had missed earlier is how this is related to GENERIC_IOMAP, since on those architectures, the ioread helpers are not just fixed-endian MMIO accessors like readl and readq but also multiplex to the PIO functions (inb/inw/inl) that do not have a 64-bit version because x86 and PCI both only define those up to 32 bit width. The best workaround is probably to use readq() instead of ioread64(), or swab64(readl()) instead of ioread64_be(). This should work on all 64-bit architectures, plus any 32-bit one that defines readq(), so you can just use an 'ifdef readq' around the call. Arnd
