Re: [PATCH] highmem: Make __kunmap_{local,atomic}() take "const void *"

[kernel test robot <lkp@intel.com>]

Hi "Fabio,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linus/master v5.19-rc2 next-20220615]
[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/intel-lab-lkp/linux/commits/Fabio-M-De-Francesco/highmem-Make-__kunmap_-local-atomic-take-const-void/20220614-222749
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
config: parisc-allyesconfig (https://download.01.org/0day-ci/archive/20220616/202206160154.0Asirpka-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 11.3.0
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/intel-lab-lkp/linux/commit/558ba1aeb12cc7940165f07160e51afb0bc1a64b
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Fabio-M-De-Francesco/highmem-Make-__kunmap_-local-atomic-take-const-void/20220614-222749
        git checkout 558ba1aeb12cc7940165f07160e51afb0bc1a64b
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 O=build_dir ARCH=parisc SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

   In file included from include/linux/highmem.h:13,
                    from include/linux/bvec.h:10,
                    from include/linux/skbuff.h:17,
                    from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
                    from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
                    from drivers/net/wwan/t7xx/t7xx_pci.c:39:
   include/linux/highmem-internal.h: In function '__kunmap_local':
>> include/linux/highmem-internal.h:203:31: error: passing argument 1 of 'kunmap_flush_on_unmap' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
     203 |         kunmap_flush_on_unmap(addr);
         |                               ^~~~
   In file included from include/linux/cacheflush.h:5,
                    from include/linux/highmem.h:8,
                    from include/linux/bvec.h:10,
                    from include/linux/skbuff.h:17,
                    from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
                    from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
                    from drivers/net/wwan/t7xx/t7xx_pci.c:39:
   arch/parisc/include/asm/cacheflush.h:78:48: note: expected 'void *' but argument is of type 'const void *'
      78 | static inline void kunmap_flush_on_unmap(void *addr)
         |                                          ~~~~~~^~~~
   In file included from include/linux/highmem.h:13,
                    from include/linux/bvec.h:10,
                    from include/linux/skbuff.h:17,
                    from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
                    from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
                    from drivers/net/wwan/t7xx/t7xx_pci.c:39:
   include/linux/highmem-internal.h: In function '__kunmap_atomic':
   include/linux/highmem-internal.h:230:31: error: passing argument 1 of 'kunmap_flush_on_unmap' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
     230 |         kunmap_flush_on_unmap(addr);
         |                               ^~~~
   In file included from include/linux/cacheflush.h:5,
                    from include/linux/highmem.h:8,
                    from include/linux/bvec.h:10,
                    from include/linux/skbuff.h:17,
                    from drivers/net/wwan/t7xx/t7xx_hif_cldma.h:25,
                    from drivers/net/wwan/t7xx/t7xx_modem_ops.h:25,
                    from drivers/net/wwan/t7xx/t7xx_pci.c:39:
   arch/parisc/include/asm/cacheflush.h:78:48: note: expected 'void *' but argument is of type 'const void *'
      78 | static inline void kunmap_flush_on_unmap(void *addr)
         |                                          ~~~~~~^~~~
   cc1: all warnings being treated as errors


vim +203 include/linux/highmem-internal.h

f3ba3c710ac5a3 Thomas Gleixner       2020-11-18  199  
558ba1aeb12cc7 Fabio M. De Francesco 2022-06-14  200  static inline void __kunmap_local(const void *addr)
f3ba3c710ac5a3 Thomas Gleixner       2020-11-18  201  {
f3ba3c710ac5a3 Thomas Gleixner       2020-11-18  202  #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
f3ba3c710ac5a3 Thomas Gleixner       2020-11-18 @203  	kunmap_flush_on_unmap(addr);
f3ba3c710ac5a3 Thomas Gleixner       2020-11-18  204  #endif
f3ba3c710ac5a3 Thomas Gleixner       2020-11-18  205  }
f3ba3c710ac5a3 Thomas Gleixner       2020-11-18  206  

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