[linux-stable-rc:linux-5.4.y 3729/5268] arch/riscv/include/asm/processor.h:68:2: error: implicit declaration of function 'barrier'

[linux-stable-rc:linux-5.4.y 3729/5268] arch/riscv/include/asm/processor.h:68:2: error: implicit declaration of function 'barrier'

[kernel test robot]

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Hi Arvind,

FYI, the error/warning still remains.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y
head:   44433bdfc6fdb454620f64bf0148f3480a45afdd
commit: c2c5dc84ac51da90cadcb12554c69bdd5ac7aeeb [3729/5268] compiler.h: fix barrier_data() on clang
config: riscv-allyesconfig (attached as .config)
compiler: riscv64-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://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=c2c5dc84ac51da90cadcb12554c69bdd5ac7aeeb
        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 linux-5.4.y
        git checkout c2c5dc84ac51da90cadcb12554c69bdd5ac7aeeb
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=riscv 

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/emulex/benet/be_main.c:14:
   arch/riscv/include/asm/processor.h: In function 'cpu_relax':
>> arch/riscv/include/asm/processor.h:68:2: error: implicit declaration of function 'barrier' [-Werror=implicit-function-declaration]
      68 |  barrier();
         |  ^~~~~~~
   cc1: some warnings being treated as errors


vim +/barrier +68 arch/riscv/include/asm/processor.h

7db91e57a0acde Palmer Dabbelt 2017-07-10  59  
7db91e57a0acde Palmer Dabbelt 2017-07-10  60  
7db91e57a0acde Palmer Dabbelt 2017-07-10  61  static inline void cpu_relax(void)
7db91e57a0acde Palmer Dabbelt 2017-07-10  62  {
7db91e57a0acde Palmer Dabbelt 2017-07-10  63  #ifdef __riscv_muldiv
7db91e57a0acde Palmer Dabbelt 2017-07-10  64  	int dummy;
7db91e57a0acde Palmer Dabbelt 2017-07-10  65  	/* In lieu of a halt instruction, induce a long-latency stall. */
7db91e57a0acde Palmer Dabbelt 2017-07-10  66  	__asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
7db91e57a0acde Palmer Dabbelt 2017-07-10  67  #endif
7db91e57a0acde Palmer Dabbelt 2017-07-10 @68  	barrier();
7db91e57a0acde Palmer Dabbelt 2017-07-10  69  }
7db91e57a0acde Palmer Dabbelt 2017-07-10  70  

:::::: The code at line 68 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

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