Hi Niklas,

I love your patch! Yet something to improve:

[auto build test ERROR on soc/for-next]
[also build test ERROR on sparc/master asm-generic/master sparc-next/master v5.12-rc7 next-20210415]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Niklas-Schnelle/asm-generic-io-h-Silence-Wnull-pointer-arithmetic-warning-on-PCI_IOBASE/20210415-203919
base:   https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
config: nds32-allnoconfig (attached as .config)
compiler: nds32le-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/f0394115b166f960f12fc7bc48362d0d19f67883
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Niklas-Schnelle/asm-generic-io-h-Silence-Wnull-pointer-arithmetic-warning-on-PCI_IOBASE/20210415-203919
        git checkout f0394115b166f960f12fc7bc48362d0d19f67883
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross W=1 ARCH=nds32 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from arch/nds32/include/asm/io.h:82,
                    from arch/nds32/kernel/vdso/gettimeofday.c:7:
   include/asm-generic/io.h: In function 'ioport_map':
>> include/asm-generic/io.h:1071:44: error: 'PCI_IOBASE' undeclared (first use in this function)
    1071 |  return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
         |                                            ^~~~~~~~~~
   include/asm-generic/io.h:1071:44: note: each undeclared identifier is reported only once for each function it appears in
   include/asm-generic/io.h: In function '__pci_ioport_unmap':
   include/asm-generic/io.h:1076:32: error: 'PCI_IOBASE' undeclared (first use in this function)
    1076 |  uintptr_t start = (uintptr_t) PCI_IOBASE;
         |                                ^~~~~~~~~~
   arch/nds32/kernel/vdso/gettimeofday.c: At top level:
   arch/nds32/kernel/vdso/gettimeofday.c:158:13: warning: no previous prototype for '__vdso_clock_gettime' [-Wmissing-prototypes]
     158 | notrace int __vdso_clock_gettime(clockid_t clkid, struct __kernel_old_timespec *ts)
         |             ^~~~~~~~~~~~~~~~~~~~
   arch/nds32/kernel/vdso/gettimeofday.c:206:13: warning: no previous prototype for '__vdso_clock_getres' [-Wmissing-prototypes]
     206 | notrace int __vdso_clock_getres(clockid_t clk_id, struct __kernel_old_timespec *res)
         |             ^~~~~~~~~~~~~~~~~~~
   arch/nds32/kernel/vdso/gettimeofday.c:246:13: warning: no previous prototype for '__vdso_gettimeofday' [-Wmissing-prototypes]
     246 | notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
         |             ^~~~~~~~~~~~~~~~~~~
--
   <stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
   In file included from arch/nds32/include/asm/io.h:82,
                    from arch/nds32/kernel/vdso/gettimeofday.c:7:
   include/asm-generic/io.h: In function 'ioport_map':
>> include/asm-generic/io.h:1071:44: error: 'PCI_IOBASE' undeclared (first use in this function)
    1071 |  return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
         |                                            ^~~~~~~~~~
   include/asm-generic/io.h:1071:44: note: each undeclared identifier is reported only once for each function it appears in
   include/asm-generic/io.h: In function '__pci_ioport_unmap':
   include/asm-generic/io.h:1076:32: error: 'PCI_IOBASE' undeclared (first use in this function)
    1076 |  uintptr_t start = (uintptr_t) PCI_IOBASE;
         |                                ^~~~~~~~~~
   arch/nds32/kernel/vdso/gettimeofday.c: At top level:
   arch/nds32/kernel/vdso/gettimeofday.c:158:13: warning: no previous prototype for '__vdso_clock_gettime' [-Wmissing-prototypes]
     158 | notrace int __vdso_clock_gettime(clockid_t clkid, struct __kernel_old_timespec *ts)
         |             ^~~~~~~~~~~~~~~~~~~~
   arch/nds32/kernel/vdso/gettimeofday.c:206:13: warning: no previous prototype for '__vdso_clock_getres' [-Wmissing-prototypes]
     206 | notrace int __vdso_clock_getres(clockid_t clk_id, struct __kernel_old_timespec *res)
         |             ^~~~~~~~~~~~~~~~~~~
   arch/nds32/kernel/vdso/gettimeofday.c:246:13: warning: no previous prototype for '__vdso_gettimeofday' [-Wmissing-prototypes]
     246 | notrace int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
         |             ^~~~~~~~~~~~~~~~~~~
   make[2]: *** [scripts/Makefile.build:271: arch/nds32/kernel/vdso/gettimeofday.o] Error 1
   make[2]: Target 'include/generated/vdso-offsets.h' not remade because of errors.
   make[1]: *** [arch/nds32/Makefile:63: vdso_prepare] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:215: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +/PCI_IOBASE +1071 include/asm-generic/io.h

7c566bb5e4d5fb0 Hector Martin     2021-02-11  1063  
ce816fa88cca083 Uwe Kleine-König  2014-04-07  1064  #ifdef CONFIG_HAS_IOPORT_MAP
3f7e212df82ca04 Arnd Bergmann     2009-05-13  1065  #ifndef CONFIG_GENERIC_IOMAP
9216efafc52ff99 Thierry Reding    2014-10-01  1066  #ifndef ioport_map
9216efafc52ff99 Thierry Reding    2014-10-01  1067  #define ioport_map ioport_map
3f7e212df82ca04 Arnd Bergmann     2009-05-13  1068  static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
3f7e212df82ca04 Arnd Bergmann     2009-05-13  1069  {
500dd232449e7c0 Andrew Murray     2018-09-13  1070  	port &= IO_SPACE_LIMIT;
500dd232449e7c0 Andrew Murray     2018-09-13 @1071  	return (port > MMIO_UPPER_LIMIT) ? NULL : PCI_IOBASE + port;
3f7e212df82ca04 Arnd Bergmann     2009-05-13  1072  }
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1073  #define __pci_ioport_unmap __pci_ioport_unmap
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1074  static inline void __pci_ioport_unmap(void __iomem *p)
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1075  {
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1076  	uintptr_t start = (uintptr_t) PCI_IOBASE;
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1077  	uintptr_t addr = (uintptr_t) p;
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1078  
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1079  	if (addr >= start && addr < start + IO_SPACE_LIMIT)
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1080  		return;
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1081  	iounmap(p);
f5810e5c329238b Lorenzo Pieralisi 2020-09-16  1082  }
9216efafc52ff99 Thierry Reding    2014-10-01  1083  #endif
3f7e212df82ca04 Arnd Bergmann     2009-05-13  1084  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org