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 <[email protected]>
>
> 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.
