[linux-stable-rc:queue/4.19 5098/9999] arch/riscv/include/asm/processor.h:82:9: error: implicit declaration of function 'barrier'

[linux-stable-rc:queue/4.19 5098/9999] arch/riscv/include/asm/processor.h:82:9: error: implicit declaration of function 'barrier'

[kernel test robot]

Hi Arvind,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git queue/4.19
head:   7725add280ae13ca07a21c62a19af15696689710
commit: b207caff4176e3a6ba273243da2db2e595e4aad2 [5098/9999] compiler.h: fix barrier_data() on clang
config: riscv-allmodconfig (https://download.01.org/0day-ci/archive/20220212/202202120007.oRXqxDqZ-lkp@intel.com/config)
compiler: riscv64-linux-gcc (GCC) 11.2.0
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://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=b207caff4176e3a6ba273243da2db2e595e4aad2
        git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
        git fetch --no-tags linux-stable-rc queue/4.19
        git checkout b207caff4176e3a6ba273243da2db2e595e4aad2
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=riscv SHELL=/bin/bash drivers/net/ethernet/mellanox/mlx5/core/

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 include/linux/prefetch.h:15,
                    from drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c:33:
   arch/riscv/include/asm/processor.h: In function 'cpu_relax':
>> arch/riscv/include/asm/processor.h:82:9: error: implicit declaration of function 'barrier' [-Werror=implicit-function-declaration]
      82 |         barrier();
         |         ^~~~~~~
   In file included from drivers/net/ethernet/mellanox/mlx5/core/en_selftest.c:37:
   At top level:
   drivers/net/ethernet/mellanox/mlx5/core/en.h:208:19: warning: 'mlx5e_priv_flags' defined but not used [-Wunused-const-variable=]
     208 | static const char mlx5e_priv_flags[][ETH_GSTRING_LEN] = {
         |                   ^~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/barrier +82 arch/riscv/include/asm/processor.h

7db91e57a0acde1 Palmer Dabbelt 2017-07-10  73  
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  74  
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  75  static inline void cpu_relax(void)
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  76  {
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  77  #ifdef __riscv_muldiv
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  78  	int dummy;
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  79  	/* In lieu of a halt instruction, induce a long-latency stall. */
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  80  	__asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  81  #endif
7db91e57a0acde1 Palmer Dabbelt 2017-07-10 @82  	barrier();
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  83  }
7db91e57a0acde1 Palmer Dabbelt 2017-07-10  84  

:::::: The code at line 82 was first introduced by commit
:::::: 7db91e57a0acde126a162ababfb1e0ab190130cb RISC-V: Task implementation

:::::: TO: Palmer Dabbelt <palmer@dabbelt.com>
:::::: CC: Palmer Dabbelt <palmer@dabbelt.com>

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