[esmil:visionfive 22/55] drivers/soc/sifive/sifive_l2_cache.c:142:19: warning: result of comparison of constant 36507222016 with expression of type 'unsigned long' is always false

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

tree:   https://github.com/esmil/linux visionfive
head:   f568ecc24aebec8ce1c59b86f2a85098675a4091
commit: 7fa12d2f832a42a37ff0d8f4dd7569cee4b0b82f [22/55] sifive/sifive_l2_cache: Add sifive_l2_flush64_range function
config: riscv-randconfig-r031-20220505 (https://download.01.org/0day-ci/archive/20220506/202205061342.dVMH03HG-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 5e004fb787698440a387750db7f8028e7cb14cfc)
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
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/esmil/linux/commit/7fa12d2f832a42a37ff0d8f4dd7569cee4b0b82f
        git remote add esmil https://github.com/esmil/linux
        git fetch --no-tags esmil visionfive
        git checkout 7fa12d2f832a42a37ff0d8f4dd7569cee4b0b82f
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/soc/sifive/

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

All warnings (new ones prefixed by >>):

   drivers/soc/sifive/sifive_l2_cache.c:152:3: error: call to undeclared function 'writeq'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
                   writeq(line, l2_base + SIFIVE_L2_FLUSH64);
                   ^
>> drivers/soc/sifive/sifive_l2_cache.c:142:19: warning: result of comparison of constant 36507222016 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare]
              (start + len) > (CONFIG_SIFIVE_L2_FLUSH_START +
              ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:56:47: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:58:86: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                                                       ~~~~~~~~~~~~~~~~~^~~~~
   include/linux/compiler.h:69:3: note: expanded from macro '__trace_if_value'
           (cond) ?                                        \
            ^~~~
>> drivers/soc/sifive/sifive_l2_cache.c:142:19: warning: result of comparison of constant 36507222016 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare]
              (start + len) > (CONFIG_SIFIVE_L2_FLUSH_START +
              ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:56:47: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:58:52: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                                      ^~~~
>> drivers/soc/sifive/sifive_l2_cache.c:142:19: warning: result of comparison of constant 36507222016 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare]
              (start + len) > (CONFIG_SIFIVE_L2_FLUSH_START +
              ~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:56:47: note: expanded from macro 'if'
   #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
                              ~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:58:61: note: expanded from macro '__trace_if_var'
   #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
                                                               ^~~~
   3 warnings and 1 error generated.


vim +142 drivers/soc/sifive/sifive_l2_cache.c

   123	
   124	#ifdef CONFIG_SIFIVE_L2_FLUSH
   125	void sifive_l2_flush64_range(unsigned long start, unsigned long len)
   126	{
   127		unsigned long line;
   128	
   129		if(!l2_base) {
   130			pr_warn("L2CACHE: base addr invalid, skipping flush\n");
   131			return;
   132		}
   133	
   134		/* TODO: if (len == 0), skipping flush or going on? */
   135		if(!len) {
   136			pr_debug("L2CACHE: flush64 range @ 0x%lx(len:0)\n", start);
   137			return;
   138		}
   139	
   140		/* make sure the address is in the range */
   141		if(start < CONFIG_SIFIVE_L2_FLUSH_START ||
 > 142		   (start + len) > (CONFIG_SIFIVE_L2_FLUSH_START +
   143				     CONFIG_SIFIVE_L2_FLUSH_SIZE)) {
   144			pr_warn("L2CACHE: flush64 out of range: %lx(%lx), skip flush\n",
   145				start, len);
   146			return;
   147		}
   148	
   149		mb();	/* sync */
   150		for (line = start; line < start + len;
   151		     line += SIFIVE_L2_FLUSH64_LINE_LEN) {
   152			writeq(line, l2_base + SIFIVE_L2_FLUSH64);
   153			mb();
   154		}
   155	}
   156	EXPORT_SYMBOL_GPL(sifive_l2_flush64_range);
   157	#endif
   158	

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