Re: [PATCH rdma-next 07/11] RDMA/erdma: Add verbs implementation

[Cheng Xu <chengyou@linux.alibaba.com>]

On 12/22/21 11:11 AM, Cheng Xu wrote:
> 
> 
> On 12/21/21 11:20 PM, Bernard Metzler wrote:
>>> -----Original Message-----
>>> From: Leon Romanovsky <leon@kernel.org>
>>> Sent: Tuesday, 21 December 2021 14:32
>>> To: Cheng Xu <chengyou@linux.alibaba.com>
>>> Cc: jgg@ziepe.ca; dledford@redhat.com; linux-rdma@vger.kernel.org;
>>> KaiShen@linux.alibaba.com; tonylu@linux.alibaba.com
>>> Subject: [EXTERNAL] Re: [PATCH rdma-next 07/11] RDMA/erdma: Add verbs
>>> implementation
>>>
>>> On Tue, Dec 21, 2021 at 10:48:54AM +0800, Cheng Xu wrote:
>>>> The RDMA verbs implementation of erdma is divided into three files:
>>>> erdma_qp.c, erdma_cq.c, and erdma_verbs.c. Internal used functions and
>>>> datapath functions of QP/CQ are put in erdma_qp.c and erdma_cq.c, the
>>> reset
>>>> is in erdma_verbs.c.
>>>>
>>>> Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com>
>>>> ---
>>>>   drivers/infiniband/hw/erdma/erdma_cq.c    |  201 +++
>>>>   drivers/infiniband/hw/erdma/erdma_qp.c    |  624 +++++++++
>>>>   drivers/infiniband/hw/erdma/erdma_verbs.c | 1477 
>>>> +++++++++++++++++++++
>>>>   3 files changed, 2302 insertions(+)
>>>>   create mode 100644 drivers/infiniband/hw/erdma/erdma_cq.c
>>>>   create mode 100644 drivers/infiniband/hw/erdma/erdma_qp.c
>>>>   create mode 100644 drivers/infiniband/hw/erdma/erdma_verbs.c
>>>
>>>
>>> Please no inline functions in .c files and no void casting for the
>>> return values of functions.
>>>
>>> <...>
>>>
>>>> diff --git a/drivers/infiniband/hw/erdma/erdma_qp.c
>>> b/drivers/infiniband/hw/erdma/erdma_qp.c
>>>> new file mode 100644
>>>> index 000000000000..8c02215cee04
>>>> --- /dev/null
>>>> +++ b/drivers/infiniband/hw/erdma/erdma_qp.c
>>>> @@ -0,0 +1,624 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * Authors: Cheng Xu <chengyou@linux.alibaba.com>
>>>> + *          Kai Shen <kaishen@linux.alibaba.com>
>>>> + * Copyright (c) 2020-2021, Alibaba Group.
>>>> + *
>>>> + * Authors: Bernard Metzler <bmt@zurich.ibm.com>
>>>> + *          Fredy Neeser <nfd@zurich.ibm.com>
>>>> + * Copyright (c) 2008-2016, IBM Corporation
>>>
>>> What does it mean?
>>>
>>
>> Significant parts of the driver have been taken from siw it seems.
>> Probably really from an old version of it.
>> In that case I would have recommended to take the upstream siw
>> code, which has been cleaned from those issues we now see again
>> (including debugfs code, extern definitions, inline in .c code,
>> casting issues, etc etc.). Why starting in 2020 with
>> code from 2016, if better code is available?
>>
>> Bernard.
> 
> First of all, thank you for developing siw, Bernard and Fredy, so we
> can build our erdma based on your work.
> At the beginning, we started developing erdma driver in kernel
> 4.9/4.19/5.10, and didn't know the upstream siw version since it is in

Correction:
At first we develop in kernel 4.9/4.19, kernel 5.10 was
added to support later.

Thanks,
Cheng Xu

> the newer kernel version. As a result, we develop erdma based on the
> older version.
> Thank you for your recommendation. We will check the differences and
> take the upstream siw code if needed.
> 
> Thanks,
> Cheng Xu