On 06/08/2020 00:48, kernel test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git > master > head: d15fe4ec043588beee823781602ddb51d0bc84c8 > commit: adcfc3482ffff813fa2c34e5902005853f79c2aa [13398/13940] sfc_ef100: > read Design Parameters at probe time > config: microblaze-randconfig-r032-20200805 (attached as .config) > compiler: microblaze-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 > git checkout adcfc3482ffff813fa2c34e5902005853f79c2aa > # save the attached .config to linux build tree > COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross > ARCH=microblaze > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <l...@intel.com> > > All errors (new ones prefixed by >>): > > microblaze-linux-ld: drivers/net/ethernet/sfc/ef100_nic.o: in function > `ef100_process_design_param': >>> drivers/net/ethernet/sfc/ef100_nic.c:610: undefined reference to `__umoddi3' > 605 /* Our TXQ and RXQ sizes are always > power-of-two and thus divisible by > 606 * EFX_MIN_DMAQ_SIZE, so we just need to check > that > 607 * EFX_MIN_DMAQ_SIZE is divisible by > GRANULARITY. > 608 * This is very unlikely to fail. > 609 */ > > 610 if (EFX_MIN_DMAQ_SIZE % reader->value) { So, this is (unsigned long) % (u64), whichI guess doesn't go quite as smoothly 32-bit microcontrollers (though the thought of plugging a 100-gig smartNIC into a microblaze boggles the mind a little ;). And none of the math64.h functions seem to have the shape we want — div_u64_rem() wants to write the remainder through a pointer, and do_div() wants to modify the dividend (which is a constant in this case). So whatever I do, it's gonna be ugly :(
Maybe I should add a static inline u32 mod_u64(u64 dividend, u32 divisor) { return do_div(dividend, divisor); } to include/linux/math64.h? At least that way the ugly is centralised in the header file.