Hi Maciej, First bad commit (maybe != root cause): tree: https://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git mips-next head: 182dd5bad52c66a54c300fe320b772456572bf23 commit: c49f71f60754acbff37505e1d16ca796bf8a8140 [98/101] MIPS: Reinstate platform `__div64_32' handler config: mips-randconfig-r036-20210421 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project d87b9b81ccb95217181ce75515c6c68bbb408ca4) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git/commit/?id... git remote add mips-linux https://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git git fetch --no-tags mips-linux mips-next git checkout c49f71f60754acbff37505e1d16ca796bf8a8140 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): do_div(avg, iters); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 1 error generated. -- kernel/time/hrtimer.c:120:21: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_REALTIME] = HRTIMER_BASE_REALTIME, ^~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:121:22: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC, ^~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:122:21: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME, ^~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:123:17: warning: initializer overrides prior initialization of this subobject [-Winitializer-overrides] [CLOCK_TAI] = HRTIMER_BASE_TAI, ^~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:118:27: note: previous initialization is here [0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES, ^~~~~~~~~~~~~~~~~~~~~~~ kernel/time/hrtimer.c:276:20: warning: unused function 'is_migration_base' [-Wunused-function] static inline bool is_migration_base(struct hrtimer_clock_base *base) ^ kernel/time/hrtimer.c:1707:20: warning: unused function '__hrtimer_peek_ahead_timers' [-Wunused-function] static inline void __hrtimer_peek_ahead_timers(void) ^ do_div(tmp, (u32) div); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 6 warnings and 1 error generated. -- In file included from kernel/time/timekeeping.c:6: In file included from include/linux/timekeeper_internal.h:10: In file included from include/linux/clocksource.h:13: In file included from include/linux/timex.h:56: In file included from include/uapi/linux/timex.h:56: In file included from include/linux/time.h:6: rl.l.high = do_div(rh.ll, divisor); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ In file included from kernel/time/timekeeping.c:6: In file included from include/linux/timekeeper_internal.h:10: In file included from include/linux/clocksource.h:13: In file included from include/linux/timex.h:56: In file included from include/uapi/linux/timex.h:56: In file included from include/linux/time.h:6: include/linux/math64.h:259:2: error: couldn't allocate output register for constraint 'x' do_div(rl.ll, divisor); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ do_div(tmp, clock->mult); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 3 errors generated. -- do_div(tmp, from); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ kernel/time/clocksource.c:675:2: error: couldn't allocate output register for constraint 'x' do_div(max_cycles, mult+maxadj); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ kernel/time/clocksource.c:869:3: error: couldn't allocate output register for constraint 'x' do_div(sec, freq); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ kernel/time/clocksource.c:870:3: error: couldn't allocate output register for constraint 'x' do_div(sec, scale); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 4 errors generated. -- do_div(shift_hz, cycles_per_tick); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ kernel/time/jiffies.c:116:2: error: couldn't allocate output register for constraint 'x' do_div(nsec_per_tick, (u32)shift_hz); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 2 errors generated. -- do_div(clc, evt->mult); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 1 error generated. -- In file included from block/partitions/core.c:12: In file included from include/linux/blktrace_api.h:5: unsigned int alignment = sector_div(sector, granularity >> SECTOR_SHIFT) ^ include/linux/math.h:121:26: note: expanded from macro 'sector_div' #define sector_div(a, b) do_div(a, b) ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ In file included from block/partitions/core.c:12: In file included from include/linux/blktrace_api.h:5: include/linux/blkdev.h:1539:11: error: couldn't allocate output register for constraint 'x' offset = sector_div(sector, granularity); ^ include/linux/math.h:121:26: note: expanded from macro 'sector_div' #define sector_div(a, b) do_div(a, b) ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 2 errors generated. -- In file included from drivers/mtd/mtdcore.c:32: do_div(sz, mtd->erasesize); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ In file included from drivers/mtd/mtdcore.c:32: include/linux/mtd/mtd.h:580:9: error: couldn't allocate output register for constraint 'x' return do_div(sz, mtd->erasesize); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ In file included from drivers/mtd/mtdcore.c:32: include/linux/mtd/mtd.h:615:2: error: couldn't allocate output register for constraint 'x' do_div(sz, mtd->writesize); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 3 errors generated. -- do_div(tmp64, curr_erasesize); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ drivers/mtd/mtdconcat.c:842:6: error: couldn't allocate output register for constraint 'x' do_div(tmp64, curr_erasesize); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ drivers/mtd/mtdconcat.c:880:3: error: couldn't allocate output register for constraint 'x' do_div(tmp64, curr_erasesize); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ drivers/mtd/mtdconcat.c:202:7: error: couldn't allocate output register for constraint 'x' if (do_div(__to, mtd->writesize) || (total_len % mtd->writesize)) ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 4 errors generated. -- remainder = do_div(tmp, wr_alignment); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ drivers/mtd/mtdpart.c:176:14: error: couldn't allocate output register for constraint 'x' remainder = do_div(tmp, wr_alignment); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ drivers/mtd/mtdpart.c:187:14: error: couldn't allocate output register for constraint 'x' remainder = do_div(tmp, wr_alignment); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 3 errors generated. -- *boffset = do_div(offset, ftl->block_size); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ drivers/mtd/sm_ftl.c:211:11: error: couldn't allocate output register for constraint 'x' *block = do_div(offset, ftl->max_lba); ^ include/asm-generic/div64.h:245:11: note: expanded from macro 'do_div' __rem = __div64_32(&(n), __base); \ ^ arch/mips/include/asm/div64.h:74:11: note: expanded from macro '__div64_32' __asm__("divu $0, %z1, %z2" \ ^ 2 errors generated. .. vim +57 kernel/time/test_udelay.c e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 27 e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 28 static int udelay_test_single(struct seq_file *s, int usecs, uint32_t iters) e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 29 { e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 30 int min = 0, max = 0, fail_count = 0; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 31 uint64_t sum = 0; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 32 uint64_t avg; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 33 int i; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 34 /* Allow udelay to be up to 0.5% fast */ e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 35 int allowed_error_ns = usecs * 5; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 36 e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 37 for (i = 0; i < iters; ++i) { 4a19bd3d22d51a kernel/time/test_udelay.c Arnd Bergmann 2016-06-17 38 s64 kt1, kt2; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 39 int time_passed; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 40 4a19bd3d22d51a kernel/time/test_udelay.c Arnd Bergmann 2016-06-17 41 kt1 = ktime_get_ns(); e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 42 udelay(usecs); 4a19bd3d22d51a kernel/time/test_udelay.c Arnd Bergmann 2016-06-17 43 kt2 = ktime_get_ns(); 4a19bd3d22d51a kernel/time/test_udelay.c Arnd Bergmann 2016-06-17 44 time_passed = kt2 - kt1; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 45 e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 46 if (i == 0 || time_passed < min) e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 47 min = time_passed; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 48 if (i == 0 || time_passed > max) e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 49 max = time_passed; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 50 if ((time_passed + allowed_error_ns) / 1000 < usecs) e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 51 ++fail_count; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 52 WARN_ON(time_passed < 0); e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 53 sum += time_passed; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 54 } e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 55 e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 56 avg = sum; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 @57 do_div(avg, iters); e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 58 seq_printf(s, "%d usecs x %d: exp=%d allowed=%d min=%d avg=%lld max=%d", e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 59 usecs, iters, usecs * 1000, e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 60 (usecs * 1000) - allowed_error_ns, min, avg, max); e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 61 if (fail_count) e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 62 seq_printf(s, " FAIL=%d", fail_count); e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 63 seq_puts(s, "\n"); e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 64 e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 65 return 0; e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 66 } e704f93af5a083 kernel/time/udelay_test.c David Riley 2014-06-16 67 :::::: The code at line 57 was first introduced by commit :::::: e704f93af5a083c07b8f722672d63a1d908daf55 kernel: time: Add udelay_test module to validate udelay :::::: TO: David Riley <davidriley(a)chromium.org&gt; :::::: CC: John Stultz <john.stultz(a)linaro.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org