[arnd-playground:randconfig-7.3-next 610/673] include/asm-generic/io.h:1099:9: error: call to undeclared function '__pa'; ISO C99 and later do not support implicit function declarations

[arnd-playground:randconfig-7.3-next 610/673] include/asm-generic/io.h:1099:9: error: call to undeclared function '__pa'; ISO C99 and later do not support implicit function declarations

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git randconfig-7.3-next
head:   0a1affa74ef2f2c5c5ee74fc604e47a1aefdd286
commit: d217cdb672619041e213243f6f352cb6422d3a59 [610/673] Revert "simplify asm/io.h"
config: um-allnoconfig (https://download.01.org/0day-ci/archive/20260925/202609251944.whUSNQ5N-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260925/202609251944.whUSNQ5N-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/202609251944.whUSNQ5N-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from lib/iomem_copy.c:8:
   In file included from include/linux/io.h:12:
   In file included from arch/um/include/asm/io.h:24:
>> include/asm-generic/io.h:1099:9: error: call to undeclared function '__pa'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1099 |         return __pa((unsigned long)address);
         |                ^
>> include/asm-generic/io.h:1107:9: error: call to undeclared function '__va'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1107 |         return __va(address);
         |                ^
>> include/asm-generic/io.h:1107:9: error: incompatible integer to pointer conversion returning 'int' from a function with result type 'void *' [-Wint-conversion]
    1107 |         return __va(address);
         |                ^~~~~~~~~~~~~
   3 errors generated.


vim +/__pa +1099 include/asm-generic/io.h

5820acdc34867d Arnd Bergmann 2026-05-08  1090  
5820acdc34867d Arnd Bergmann 2026-05-08  1091  /*
5820acdc34867d Arnd Bergmann 2026-05-08  1092   * Change virtual addresses to physical addresses and vv.
5820acdc34867d Arnd Bergmann 2026-05-08  1093   * These are pretty trivial
5820acdc34867d Arnd Bergmann 2026-05-08  1094   */
5820acdc34867d Arnd Bergmann 2026-05-08  1095  #ifndef virt_to_phys
5820acdc34867d Arnd Bergmann 2026-05-08  1096  #define virt_to_phys virt_to_phys
5820acdc34867d Arnd Bergmann 2026-05-08  1097  static inline unsigned long virt_to_phys(volatile void *address)
5820acdc34867d Arnd Bergmann 2026-05-08  1098  {
5820acdc34867d Arnd Bergmann 2026-05-08 @1099  	return __pa((unsigned long)address);
5820acdc34867d Arnd Bergmann 2026-05-08  1100  }
5820acdc34867d Arnd Bergmann 2026-05-08  1101  #endif
5820acdc34867d Arnd Bergmann 2026-05-08  1102  
5820acdc34867d Arnd Bergmann 2026-05-08  1103  #ifndef phys_to_virt
5820acdc34867d Arnd Bergmann 2026-05-08  1104  #define phys_to_virt phys_to_virt
5820acdc34867d Arnd Bergmann 2026-05-08  1105  static inline void *phys_to_virt(unsigned long address)
5820acdc34867d Arnd Bergmann 2026-05-08  1106  {
5820acdc34867d Arnd Bergmann 2026-05-08 @1107  	return __va(address);
5820acdc34867d Arnd Bergmann 2026-05-08  1108  }
5820acdc34867d Arnd Bergmann 2026-05-08  1109  #endif
5820acdc34867d Arnd Bergmann 2026-05-08  1110  

:::::: The code at line 1099 was first introduced by commit
:::::: 5820acdc34867db3abad330764e2069a3fb15216 Revert "asm/io.h: move virt_to_phys/phys_to_virt"

:::::: TO: Arnd Bergmann <arnd@arndb.de>
:::::: CC: Arnd Bergmann <arnd@arndb.de>

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