[crng-random:jd/not-zero-entropy 3/12] include/linux/timex.h:83:49: error: implicit declaration of function 'sched_clock'

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

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git jd/not-zero-entropy
head:   efec3e2057963ad20223fa50a657b3ca9314ed45
commit: d921ec2a978ab8566577c18abfe20960dd0c6477 [3/12] random: use sched_clock() for random_get_entropy() if no get_cycles()
config: powerpc-allnoconfig (https://download.01.org/0day-ci/archive/20220411/202204110149.L9WMl0vi-lkp@intel.com/config)
compiler: powerpc-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/crng/random.git/commit/?id=d921ec2a978ab8566577c18abfe20960dd0c6477
        git remote add crng-random git://git.kernel.org/pub/scm/linux/kernel/git/crng/random.git
        git fetch --no-tags crng-random jd/not-zero-entropy
        git checkout d921ec2a978ab8566577c18abfe20960dd0c6477
        # 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=powerpc SHELL=/bin/bash

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/time32.h:13,
                    from include/linux/time.h:60,
                    from include/linux/jiffies.h:10,
                    from lib/random32.c:38:
   lib/random32.c: In function 'prandom_init_early':
>> include/linux/timex.h:83:49: error: implicit declaration of function 'sched_clock' [-Werror=implicit-function-declaration]
      83 | #define random_get_entropy()    ((unsigned long)sched_clock())
         |                                                 ^~~~~~~~~~~
   lib/random32.c:469:22: note: in expansion of macro 'random_get_entropy'
     469 |                 v1 = random_get_entropy();
         |                      ^~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/sched_clock +83 include/linux/timex.h

    66	
    67	#ifndef random_get_entropy
    68	/*
    69	 * The random_get_entropy() function is used by the /dev/random driver
    70	 * in order to extract entropy via the relative unpredictability of
    71	 * when an interrupt takes places versus a high speed, fine-grained
    72	 * timing source or cycle counter.  Since it will be occurred on every
    73	 * single interrupt, it must have a very low cost/overhead.
    74	 *
    75	 * By default we use get_cycles() for this purpose, but individual
    76	 * architectures may override this in their asm/timex.h header file.
    77	 * If a given arch does not have get_cycles(), then we fallback to
    78	 * using sched_clock().
    79	 */
    80	#ifdef get_cycles
    81	#define random_get_entropy()	((unsigned long)get_cycles())
    82	#else
  > 83	#define random_get_entropy()	((unsigned long)sched_clock())
    84	#endif
    85	#endif
    86	

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