Re: [PATCH for-next] RDMA/hns: Add support for extended atomic

[Weihang Li <liweihang@huawei.com>]

On 2020/1/3 5:03, Jason Gunthorpe wrote:
> On Fri, Nov 15, 2019 at 09:39:26AM +0800, Weihang Li wrote:
>> From: Jiaran Zhang <zhangjiaran@huawei.com>
>>
>> Support extended atomic operations including cmp & swap and fetch & add
>> of 8 bytes, 16 bytes, 32 bytes, 64 bytes on hip08.
>>
>> Signed-off-by: Jiaran Zhang <zhangjiaran@huawei.com>
>> Signed-off-by: Weihang Li <liweihang@hisilicon.com>
>> ---
>>  drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 100 ++++++++++++++++++++++++-----
>>  drivers/infiniband/hw/hns/hns_roce_hw_v2.h |   8 +++
>>  2 files changed, 93 insertions(+), 15 deletions(-)
> 
> How is this related to the userspace patch:
> 
> https://github.com/linux-rdma/rdma-core/pull/640
> 
> ?
> 
> Under what conditions would the kernel part be needed?
> 
> Confused because we have no kernel users of extended atomic.
> 
> Jason
> 
> 

Hi Jason,

This patch has no relationship with the userspace one you pointed out.
But I have pushed a userspace patch that support extended atomic on hip08,
maybe you were asking about the following one:

https://github.com/linux-rdma/rdma-core/pull/638

The kernel part is not needed by the userspace part, they are independent
of each other.

We made this patch because we noticed that some other providers has also
support this feature in kernel, maybe there will be some kernel users in
future. I would be grateful if you could give me more suggestions.

Thank you
Weihang