Re: [dpdk-dev] [EXT] Re: [PATCH v5 1/3] net/thunderx: enable build only on 64-bit Linux

[Pavan Nikhilesh Bhagavatula <pbhagavatula@marvell.com>]

>On 10/4/2021 1:01 PM, Pavan Nikhilesh Bhagavatula wrote:
>>> On 10/4/2021 12:34 PM, Pavan Nikhilesh Bhagavatula wrote:
>>>>> On 10/4/2021 11:02 AM, Pavan Nikhilesh Bhagavatula wrote:
>>>>>>> On 10/4/2021 6:56 AM, pbhagavatula@marvell.com wrote:
>>>>>>>> From: Pavan Nikhilesh <pbhagavatula@marvell.com>
>>>>>>>>
>>>>>>>> Due to Linux kernel AF(Admin function) driver dependency,
>only
>>>>>>> enable
>>>>>>>> build for 64-bit Linux.
>>>>>>>>
>>>>>>>
>>>>>>> Hi Pavan,
>>>>>>>
>>>>>>> Isn't it possible to provide a commit log in the kernel side etc,
>that
>>> let
>>>>>>> others to verify why only 64 bit is required, or if someone want
>to
>>>>>>> support
>>>>>>> 32bit that may help them to investigate the source of the
>>> restriction.
>>>>>>
>>>>>> Arch 32 support is not implemented on ThunderX, so 32bit will
>not
>>>>> run.
>>>>>>
>>>>>
>>>>> I see, is following correct:
>>>>> All thunderx, octeonx & octeontx2 only supports VF in the DPDK,
>>> and PF
>>>>> is
>>>>> supported by Linux kernel driver. And Linux kernel driver doesn't
>>>>> support arch32.
>>>>
>>>> AF != PF, AF is something that manages all the shared resources
>>> between PF/VF.
>>>>
>>>
>>> I see, I though AF is part of PF functionality. Are there two different
>>> kernel
>>> modules for PF and AF?
>>>
>>> So can DPDK driver drive PF? In a way, PF by DPDK, VF by DPDK, AF
>by
>>> Linux
>>> kernel driver.
>>
>> Yup that’s correct.
>>
>>>
>>>>>
>>>>> Is something changed in kernel driver side to drop the 32bit
>support?
>>>>> If it was not supported at all, what is the motivation to disable the
>>> DPDK
>>>>> drivers now?
>>>>>
>>>>
>>>> It was never supported to begin with, motivation is that build will
>fail if
>>> we try to
>>>> compile with 32b.
>>>>
>>>
>>> If there is no plan to support 32bit in the kernel side, that is
>reasonable
>>> to
>>> disable 32bit build, please provide above details in the commit log.
>>>
>>> And after above said, how much maintenance cost to support 32bit,
>if
>>> the build
>>> error is on the logging format "%lx" etc .. (as we mostly have 32bit
>build
>>> errors), it is better to fix them using 'PRIx64' which is more proper
>way
>>> anyway. If there is more logical issue with 32bit pointers, I agree with
>>> you to
>>> disable it.
>>> Can you please provided the build error in the commit log as record?
>>>
>>
>> Apologies, I meant that all the functions that don’t fall under 64b are
>stubbed out
>> so the driver wouldn’t work.
>>
>
>so is there build error or not?
>

No build error.

>>>>>>>
>>>>>>>> Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
>>>>>>>> Acked-by: Jerin Jacob <jerinj@marvell.com>
>>>>>>>> ---
>>>>>>>>  v5 Changes
>>>>>>>>  - s/fuction/function.
>>>>>>>>
>>>>>>>>  v4 Changes:
>>>>>>>>  - Update commit message regarding dependency on AF
>driver.
>>>>>>>>
>>>>>>>>  drivers/net/thunderx/meson.build | 4 ++--
>>>>>>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/net/thunderx/meson.build
>>>>>>> b/drivers/net/thunderx/meson.build
>>>>>>>> index 4bbcea7f93..da665bd76f 100644
>>>>>>>> --- a/drivers/net/thunderx/meson.build
>>>>>>>> +++ b/drivers/net/thunderx/meson.build
>>>>>>>> @@ -1,9 +1,9 @@
>>>>>>>>  # SPDX-License-Identifier: BSD-3-Clause
>>>>>>>>  # Copyright(c) 2017 Cavium, Inc
>>>>>>>>
>>>>>>>> -if is_windows
>>>>>>>> +if not is_linux or not dpdk_conf.get('RTE_ARCH_64')
>>>>>>>>      build = false
>>>>>>>> -    reason = 'not supported on Windows'
>>>>>>>> +    reason = 'only supported on 64-bit Linux'
>>>>>>>>      subdir_done()
>>>>>>>>  endif
>>>>>>>>
>>>>>>>> --
>>>>>>>> 2.17.1
>>>>>>>>
>>>>>>
>>>>
>>