On 2021/11/22 16:58, Leon Romanovsky wrote:
>> entry = to_hns_mmap(rdma_entry);
>> pfn = entry->address >> PAGE_SHIFT;
>> - prot = vma->vm_page_prot;
>>
>> - if (entry->mmap_type != HNS_ROCE_MMAP_TYPE_TPTR)
>> - prot = pgprot_noncached(prot);
>> + switch (entry->mmap_type) {
>> + case HNS_ROCE_MMAP_TYPE_DB:
>> + prot = pgprot_noncached(vma->vm_page_prot);
>> + break;
>> + case HNS_ROCE_MMAP_TYPE_TPTR:
>> + prot = vma->vm_page_prot;
>> + break;
>> + case HNS_ROCE_MMAP_TYPE_DWQE:
>> + prot = pgprot_device(vma->vm_page_prot);
> Everything fine, except this pgprot_device(). You probably need to check
> WC internally in your driver and use or pgprot_writecombine() or
> pgprot_noncached() explicitly.
>
> Thanks
> .
>
This issue is also discussed in the v2 version, direct wqe uses
this prot on HIP09 can achieve better performance than NC.
v2 link: https://patchwork.kernel.org/project/linux-rdma/patch/1622705834-19353-3-git-send-email-liweihang@xxxxxxxxxx/
Thanks
Wenpeng
