On 2021/6/4 3:12, Jason Gunthorpe wrote:
> On Thu, Jun 03, 2021 at 03:37:13PM +0800, Weihang Li wrote:
>> From: Xi Wang <wangxi11@xxxxxxxxxx>
>>
>> Classify the uar address by wrapping the uar type and start page as offset
>> for hns rdma io mmap.
>>
>> Signed-off-by: Xi Wang <wangxi11@xxxxxxxxxx>
>> Signed-off-by: Weihang Li <liweihang@xxxxxxxxxx>
>> drivers/infiniband/hw/hns/hns_roce_main.c | 27 ++++++++++++++++++++++++---
>> include/uapi/rdma/hns-abi.h | 4 ++++
>> 2 files changed, 28 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/hns/hns_roce_main.c b/drivers/infiniband/hw/hns/hns_roce_main.c
>> index 6c6e82b..9610bfd 100644
>> +++ b/drivers/infiniband/hw/hns/hns_roce_main.c
>> @@ -338,12 +338,23 @@ static void hns_roce_dealloc_ucontext(struct ib_ucontext *ibcontext)
>> hns_roce_uar_free(to_hr_dev(ibcontext->device), &context->uar);
>> }
>>
>> -static int hns_roce_mmap(struct ib_ucontext *context,
>> - struct vm_area_struct *vma)
>> +/* command value is offset[15:8] */
>> +static int hns_roce_mmap_get_command(unsigned long offset)
>> +{
>> + return (offset >> 8) & 0xff;
>> +}
>> +
>> +/* index value is offset[63:16] | offset[7:0] */
>> +static unsigned long hns_roce_mmap_get_index(unsigned long offset)
>> +{
>> + return ((offset >> 16) << 8) | (offset & 0xff);
>> +}
>
> Please try to avoid using this command stuff copied from mlx drivers,
> especially do not encode the qpn in this.
>
> The proper way is to request and return a mmap cookie through the
> verb that causes the page to be allocated. For instance specifying a
> new input parameter to the create QP udata and an output parameter
> with the mmap cookie.
>
> You can look at what the mlx UAR stuff does for some idea how to
> convert the old command style to a the preferred cookie style.
>
> Jason
>
Thank you, we'll look at the implementation of mlx and how to use the existing
interfaces in the framework.
Weihang
