Re: [PATCH v2 for-rc 3/5] RDMA/hns: Remove enable rq inline in kernel and add compatibility handling

[Jason Gunthorpe <jgg@nvidia.com>]

On Wed, Oct 26, 2022 at 05:50:52PM +0800, Haoyue Xu wrote:
> From: Luoyouming <luoyouming@huawei.com>
> 
> The rq inline makes some changes as follows, Firstly, it is only
> used in user space. Secondly, it should notify hardware in QP RTR
> status. Thirdly, Add compatibility processing between different
> user space and kernel space. Change the HNS_ROCE_CAP_FLAG_RQ_INLINE
> to a new bit to prevent old kernel spaces / spaced from enabling
> rq inline.
> 
> Signed-off-by: Luoyouming <luoyouming@huawei.com>
> Signed-off-by: Haoyue Xu <xuhaoyue1@hisilicon.com>
> ---
>  drivers/infiniband/hw/hns/hns_roce_device.h |  6 +++--
>  drivers/infiniband/hw/hns/hns_roce_hw_v2.c  | 28 +++++++++++++--------
>  drivers/infiniband/hw/hns/hns_roce_main.c   |  5 ++++
>  drivers/infiniband/hw/hns/hns_roce_qp.c     |  2 +-
>  include/uapi/rdma/hns-abi.h                 |  2 ++
>  5 files changed, 30 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
> index f701cc86896b..9ce053fe737d 100644
> --- a/drivers/infiniband/hw/hns/hns_roce_device.h
> +++ b/drivers/infiniband/hw/hns/hns_roce_device.h
> @@ -132,7 +132,8 @@ enum hns_roce_event {
>  enum {
>  	HNS_ROCE_CAP_FLAG_REREG_MR		= BIT(0),
>  	HNS_ROCE_CAP_FLAG_ROCE_V1_V2		= BIT(1),
> -	HNS_ROCE_CAP_FLAG_RQ_INLINE		= BIT(2),
> +	/* discard this bit, reserved for compatibility */
> +	HNS_ROCE_CAP_FLAG_DISCARD		= BIT(2),

If it is for compatability with userspace why is this enum not under
include/uapi? Something has gone wrong here, please fix it.

Also, it is better to name this __HNS_ROCE_CAP_FLAG_RQ_INLINE to
indicate it is not used instead of 'discard'

Jason