Re: [akpm-mm:mm-unstable 93/173] drivers/clk/clk-fixed-mmio.c:33:2: error: call to undeclared function 'iounmap'; ISO C99 and later do not support implicit function declarations

[Baoquan He <bhe@redhat.com>]

Hi Andrew,

On 07/13/23 at 09:26am, Andrew Morton wrote:
> On Thu, 13 Jul 2023 10:57:34 +0800 kernel test robot <lkp@intel.com> wrote:
> 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable
> > head:   e726c62e70a70ae5536caa0aa131c5dce5c6f764
> > commit: 827057ff3ce7554741d431145c3b93f1a54125fc [93/173] s390: mm: convert to GENERIC_IOREMAP
> > config: s390-randconfig-r033-20230713 (https://download.01.org/0day-ci/archive/20230713/202307131033.JgvCSVz4-lkp@intel.com/config)
> > compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
> > reproduce: (https://download.01.org/0day-ci/archive/20230713/202307131033.JgvCSVz4-lkp@intel.com/reproduce)
> > 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202307131033.JgvCSVz4-lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>):
> > 
> >    In file included from drivers/clk/clk-fixed-mmio.c:13:
> >    In file included from include/linux/io.h:13:
> >    In file included from arch/s390/include/asm/io.h:78:
> >    include/asm-generic/io.h:547:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
> >      547 |         val = __raw_readb(PCI_IOBASE + addr);
> >          |                           ~~~~~~~~~~ ^
> 
> Thanks.  When I tried that config I got

These two kinds of errors have been reported many times.

This PCI_IOBASE warning will be fixed by Niklas's patch at below:

https://lore.kernel.org/20230522105049.1467313-1-schnelle@linux.ibm.com/


Nathan told this when he reviewed by patch at this sub-thread:
https://lore.kernel.org/all/20230612160237.GA199007@dev-arch.thelio-3990X/T/#u

Quote his words here:
===
I believe that this series [1] by Niklas Schnelle should take care of
the PCI_IOBASE warnings (which are not Hexagon specific), so there is no
need to worry about them when they show up in build reports.

[1]: https://lore.kernel.org/20230522105049.1467313-1-schnelle@linux.ibm.com/

Cheers,
Nathan
===



> 
> In file included from ./include/linux/io.h:13,
>                  from drivers/clk/clk-fixed-mmio.c:13:
> drivers/clk/clk-fixed-mmio.c: In function 'fixed_mmio_clk_setup':
> ./arch/s390/include/asm/io.h:29:17: error: implicit declaration of function 'iounmap'; did you mean 'vunmap'? [-Werror=implicit-function-declaration]
>    29 | #define iounmap iounmap
>       |                 ^~~~~~~
> drivers/clk/clk-fixed-mmio.c:33:9: note: in expansion of macro 'iounmap'
>    33 |         iounmap(base);
>       |         ^~~~~~~

These iorempa/iounmap not defined or declared are not related to my
patches. S390 could set CONFIG_PCI=n, however its ioremap/iounmap code
are all defined in arch/s390/pci/pci.c. Means its ioremap/iounmap code
depends on CONFIG_PCI enabling. So those drivers invoking iomem
functions, (e.g ioremap(), devm_ioremap(), etc) all will be failed to
build if CONFIG_PCI=n on s390.

All these errors have been fixed in my another patchset.

https://lore.kernel.org/all/20230707135852.24292-1-bhe@redhat.com/T/#u

> 
> I'll drop the series.

I didn't reply this time because these have been reported repeatedly
recently, I have replied to explain many times in different lkp test
robot. They are all the same two things.

Conclusion:
===========
PCI_IOBASE warning
 - taken care by Niklas's patchset
 - https://lore.kernel.org/20230522105049.1467313-1-schnelle@linux.ibm.com/
ioremap/iounmap/devm_ioremap_xxx not declared
 - existed for very long time, but not caused by my patches, and fixed in my another patchset
 - https://lore.kernel.org/all/20230707135852.24292-1-bhe@redhat.com/T/#u

Thanks