[linux-next:master 13398/13940] drivers/net/ethernet/sfc/ef100_nic.c:610: undefined reference to `__umoddi3'
9:48 a.m.
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 <lkp(a)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'
vim +610 drivers/net/ethernet/sfc/ef100_nic.c
567
568 static int ef100_process_design_param(struct efx_nic *efx,
569 const struct ef100_tlv_state *reader)
570 {
571 struct ef100_nic_data *nic_data = efx->nic_data;
572
573 switch (reader->type) {
574 case ESE_EF100_DP_GZ_PAD: /* padding, skip it */
575 return 0;
576 case ESE_EF100_DP_GZ_PARTIAL_TSTAMP_SUB_NANO_BITS:
577 /* Driver doesn't support timestamping yet, so we don't care */
578 return 0;
579 case ESE_EF100_DP_GZ_EVQ_UNSOL_CREDIT_SEQ_BITS:
580 /* Driver doesn't support unsolicited-event credits yet, so
581 * we don't care
582 */
583 return 0;
584 case ESE_EF100_DP_GZ_NMMU_GROUP_SIZE:
585 /* Driver doesn't manage the NMMU (so we don't care) */
586 return 0;
587 case ESE_EF100_DP_GZ_RX_L4_CSUM_PROTOCOLS:
588 /* Driver uses CHECKSUM_COMPLETE, so we don't care about
589 * protocol checksum validation
590 */
591 return 0;
592 case ESE_EF100_DP_GZ_TSO_MAX_HDR_LEN:
593 nic_data->tso_max_hdr_len = min_t(u64, reader->value, 0xffff);
594 return 0;
595 case ESE_EF100_DP_GZ_TSO_MAX_HDR_NUM_SEGS:
596 /* We always put HDR_NUM_SEGS=1 in our TSO descriptors */
597 if (!reader->value) {
598 netif_err(efx, probe, efx->net_dev,
599 "TSO_MAX_HDR_NUM_SEGS < 1\n");
600 return -EOPNOTSUPP;
601 }
602 return 0;
603 case ESE_EF100_DP_GZ_RXQ_SIZE_GRANULARITY:
604 case ESE_EF100_DP_GZ_TXQ_SIZE_GRANULARITY:
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) {
611 netif_err(efx, probe, efx->net_dev,
612 "%s size granularity is %llu, can't guarantee safety\n",
613 reader->type == ESE_EF100_DP_GZ_RXQ_SIZE_GRANULARITY ? "RXQ" :
"TXQ",
614 reader->value);
615 return -EOPNOTSUPP;
616 }
617 return 0;
618 case ESE_EF100_DP_GZ_TSO_MAX_PAYLOAD_LEN:
619 nic_data->tso_max_payload_len = min_t(u64, reader->value, GSO_MAX_SIZE);
620 efx->net_dev->gso_max_size = nic_data->tso_max_payload_len;
621 return 0;
622 case ESE_EF100_DP_GZ_TSO_MAX_PAYLOAD_NUM_SEGS:
623 nic_data->tso_max_payload_num_segs = min_t(u64, reader->value, 0xffff);
624 efx->net_dev->gso_max_segs = nic_data->tso_max_payload_num_segs;
625 return 0;
626 case ESE_EF100_DP_GZ_TSO_MAX_NUM_FRAMES:
627 nic_data->tso_max_frames = min_t(u64, reader->value, 0xffff);
628 return 0;
629 case ESE_EF100_DP_GZ_COMPAT:
630 if (reader->value) {
631 netif_err(efx, probe, efx->net_dev,
632 "DP_COMPAT has unknown bits %#llx, driver not compatible with this
hw\n",
633 reader->value);
634 return -EOPNOTSUPP;
635 }
636 return 0;
637 case ESE_EF100_DP_GZ_MEM2MEM_MAX_LEN:
638 /* Driver doesn't use mem2mem transfers */
639 return 0;
640 case ESE_EF100_DP_GZ_EVQ_TIMER_TICK_NANOS:
641 /* Driver doesn't currently use EVQ_TIMER */
642 return 0;
643 case ESE_EF100_DP_GZ_NMMU_PAGE_SIZES:
644 /* Driver doesn't manage the NMMU (so we don't care) */
645 return 0;
646 case ESE_EF100_DP_GZ_VI_STRIDES:
647 /* We never try to set the VI stride, and we don't rely on
648 * being able to find VIs past VI 0 until after we've learned
649 * the current stride from MC_CMD_GET_CAPABILITIES.
650 * So the value of this shouldn't matter.
651 */
652 if (reader->value != ESE_EF100_DP_GZ_VI_STRIDES_DEFAULT)
653 netif_dbg(efx, probe, efx->net_dev,
654 "NIC has other than default VI_STRIDES (mask "
655 "%#llx), early probing might use wrong one\n",
656 reader->value);
657 return 0;
658 case ESE_EF100_DP_GZ_RX_MAX_RUNT:
659 /* Driver doesn't look at L2_STATUS:LEN_ERR bit, so we don't
660 * care whether it indicates runt or overlength for any given
661 * packet, so we don't care about this parameter.
662 */
663 return 0;
664 default:
665 /* Host interface says "Drivers should ignore design parameters
666 * that they do not recognise."
667 */
668 netif_dbg(efx, probe, efx->net_dev,
669 "Ignoring unrecognised design parameter %u\n",
670 reader->type);
671 return 0;
672 }
673 }
674
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
4:17 a.m.
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 <lkp(a)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.
1:51 a.m.
On Thu, Aug 06, 2020 at 07:17:43PM +0100, Edward Cree wrote:
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 <lkp(a)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);
}
Your proposed function is an exact replicate of do_div() and thus doesn't
make much sense. Also, in your case, divisor is a 64-bit value, which is
causing the problem to start with. You could try something like
if (reader->value > EFX_MIN_DMAQ_SIZE || EFX_MIN_DMAQ_SIZE %
(u32)reader->value)
If EFX_MIN_DMAQ_SIZE is indeed known to be a power of 2, you could also use
the knowledge that a 2^n value can only be divided by a smaller 2^n value,
meaning that reader->value must have exactly one bit set. This would also
avoid divide-by-0 issues if reader->value can be 0.
if (reader->value > EFX_MIN_DMAQ_SIZE || hweight64(reader->value) != 1)
Guenter
6:55 p.m.
On 10/08/2020 16:51, Guenter Roeck wrote:
On Thu, Aug 06, 2020 at 07:17:43PM +0100, Edward Cree wrote:
> Maybe I should add a
>
> static inline u32 mod_u64(u64 dividend, u32 divisor)
> {
> return do_div(dividend, divisor);
> }
Your proposed function is an exact replicate of do_div()
No, because do_div() is a
macro that modifies 'dividend', whereas by
wrapping it in an inline function mod_u64() implicitly creates a
local variable. Thus do_div() cannot be used on a constant, whereas
mod_u64() can.
You could try something like
if (reader->value > EFX_MIN_DMAQ_SIZE || EFX_MIN_DMAQ_SIZE %
(u32)reader->value)
I considered that. It's ugly, so while it will work I
think it's
worthlooking to see if there's a better way.
If EFX_MIN_DMAQ_SIZE is indeed known to be a power of 2, you could
also use
the knowledge that a 2^n value can only be divided by a smaller 2^n value,
meaning that reader->value must have exactly one bit set. This would also
avoid divide-by-0 issues if reader->value can be 0.
if (reader->value > EFX_MIN_DMAQ_SIZE || hweight64(reader->value) != 1)
This is also ugly and I don't like relying on the power-of-twoness —
it just feels fragile.
But you're right to point out that there's a div/0 issue, and if I'm
going to have to check for that, then ugliness is unavoidable. So
I think the least painful option available is probably
if (!reader->value || reader->value > EFX_MIN_DMAQ_SIZE ||
EFX_MIN_DMAQ_SIZE % (u32)reader->value)
which only assumes EFX_MIN_DMAQ_SIZE <= U32_MAX, an assumption I'm
comfortable with baking in.
I'll put together a formal patch with that.
Thanks for the help.
-ed
770
days inactive
776
days old
3 comments
3 participants
participants (3)
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Edward Cree -
Guenter Roeck -
kernel test robot