2020-02-14 19:24:37

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH rdma] IB/mlx5: Fix linkage failure on 32-bit arches

On Fri, Feb 14, 2020 at 10:13:09PM +0300, Alexander Lobakin wrote:
> Commit f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
> capabilities") introduced a straight "/" division of the u64
> variable "bar_size", which emits an __udivdi3() libgcc call on
> 32-bit arches and certain GCC versions:
>
> error: "__udivdi3" [drivers/infiniband/hw/mlx5/mlx5_ib.ko] undefined! [1]
>
> Replace it with the corresponding div_u64() call.
> Compile-tested on ARCH=mips 32r2el_defconfig BOARDS=ocelot.
>
> [1] https://lore.kernel.org/linux-mips/CAMuHMdXM9S1VkFMZ8eDAyZR6EE4WkJY215Lcn2qdOaPeadF+EQ@mail.gmail.com/
>
> Fixes: f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
> capabilities")
> Signed-off-by: Alexander Lobakin <[email protected]>
> ---
> drivers/infiniband/hw/mlx5/main.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

Randy beat you too it..

https://lore.kernel.org/linux-rdma/[email protected]/

But it seems patchwork missed this somehow.

Applied now at least

Jason


2020-02-14 19:45:05

by Alexander Lobakin

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Subject: Re: [PATCH rdma] IB/mlx5: Fix linkage failure on 32-bit arches

Jason Gunthorpe wrote 14.02.2020 22:24:
> On Fri, Feb 14, 2020 at 10:13:09PM +0300, Alexander Lobakin wrote:
>> Commit f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
>> capabilities") introduced a straight "/" division of the u64
>> variable "bar_size", which emits an __udivdi3() libgcc call on
>> 32-bit arches and certain GCC versions:
>>
>> error: "__udivdi3" [drivers/infiniband/hw/mlx5/mlx5_ib.ko] undefined!
>> [1]
>>
>> Replace it with the corresponding div_u64() call.
>> Compile-tested on ARCH=mips 32r2el_defconfig BOARDS=ocelot.
>>
>> [1]
>> https://lore.kernel.org/linux-mips/CAMuHMdXM9S1VkFMZ8eDAyZR6EE4WkJY215Lcn2qdOaPeadF+EQ@mail.gmail.com/
>>
>> Fixes: f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
>> capabilities")
>> Signed-off-by: Alexander Lobakin <[email protected]>
>> ---
>> drivers/infiniband/hw/mlx5/main.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> Randy beat you too it..
>
> https://lore.kernel.org/linux-rdma/[email protected]/

Ah, OK. Sorry for missing this one. I didn't see any fix over
git.kernel.org and thought it doesn't exist yet.

> But it seems patchwork missed this somehow.
>
> Applied now at least

Thanks!

> Jason

Regards,
ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ

2020-02-16 11:55:20

by Maxim Mikityanskiy

[permalink] [raw]
Subject: Re: [PATCH rdma] IB/mlx5: Fix linkage failure on 32-bit arches

On 2020-02-14 21:44, Alexander Lobakin wrote:
> Jason Gunthorpe wrote 14.02.2020 22:24:
>> On Fri, Feb 14, 2020 at 10:13:09PM +0300, Alexander Lobakin wrote:
>>> Commit f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
>>> capabilities") introduced a straight "/" division of the u64
>>> variable "bar_size", which emits an __udivdi3() libgcc call on
>>> 32-bit arches and certain GCC versions:
>>>
>>> error: "__udivdi3" [drivers/infiniband/hw/mlx5/mlx5_ib.ko] undefined!
>>> [1]
>>>
>>> Replace it with the corresponding div_u64() call.
>>> Compile-tested on ARCH=mips 32r2el_defconfig BOARDS=ocelot.
>>>
>>> [1]
>>> https://lore.kernel.org/linux-mips/CAMuHMdXM9S1VkFMZ8eDAyZR6EE4WkJY215Lcn2qdOaPeadF+EQ@mail.gmail.com/
>>>
>>>
>>> Fixes: f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
>>> capabilities")
>>> Signed-off-by: Alexander Lobakin <[email protected]>
>>> ---
>>>  drivers/infiniband/hw/mlx5/main.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> Randy beat you too it..
>>
>> https://lore.kernel.org/linux-rdma/[email protected]/
>
> Ah, OK. Sorry for missing this one. I didn't see any fix over
> git.kernel.org and thought it doesn't exist yet.
>
>> But it seems patchwork missed this somehow.
>>
>> Applied now at least

Jason, I think Alexander's patch is more correct. It uses div_u64, while
yours uses div64_u64. The divider is 32-bit, so div_u64 would be more
optimized on most 32-bit architectures.

> Thanks!
>
>> Jason
>
> Regards,
> ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ

2020-02-17 00:36:35

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH rdma] IB/mlx5: Fix linkage failure on 32-bit arches

On Sun, Feb 16, 2020 at 01:53:50PM +0200, Maxim Mikityanskiy wrote:
> On 2020-02-14 21:44, Alexander Lobakin wrote:
> > Jason Gunthorpe wrote 14.02.2020 22:24:
> > > On Fri, Feb 14, 2020 at 10:13:09PM +0300, Alexander Lobakin wrote:
> > > > Commit f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
> > > > capabilities") introduced a straight "/" division of the u64
> > > > variable "bar_size", which emits an __udivdi3() libgcc call on
> > > > 32-bit arches and certain GCC versions:
> > > >
> > > > error: "__udivdi3" [drivers/infiniband/hw/mlx5/mlx5_ib.ko]
> > > > undefined! [1]
> > > >
> > > > Replace it with the corresponding div_u64() call.
> > > > Compile-tested on ARCH=mips 32r2el_defconfig BOARDS=ocelot.
> > > >
> > > > [1] https://lore.kernel.org/linux-mips/CAMuHMdXM9S1VkFMZ8eDAyZR6EE4WkJY215Lcn2qdOaPeadF+EQ@mail.gmail.com/
> > > >
> > > >
> > > > Fixes: f164be8c0366 ("IB/mlx5: Extend caps stage to handle VAR
> > > > capabilities")
> > > > Signed-off-by: Alexander Lobakin <[email protected]>
> > > >  drivers/infiniband/hw/mlx5/main.c | 3 ++-
> > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > Randy beat you too it..
> > >
> > > https://lore.kernel.org/linux-rdma/[email protected]/
> >
> > Ah, OK. Sorry for missing this one. I didn't see any fix over
> > git.kernel.org and thought it doesn't exist yet.
> >
> > > But it seems patchwork missed this somehow.
> > >
> > > Applied now at least
>
> Jason, I think Alexander's patch is more correct. It uses div_u64, while
> yours uses div64_u64. The divider is 32-bit, so div_u64 would be more
> optimized on most 32-bit architectures.

Seems so, but it is already done. You can send a followup to fix it

Jason