[PATCH] udmabuf: Add support for mapping hugepages (v4)

[Gerd Hoffmann]

On Wed, Jun 09, 2021 at 11:29:15AM -0700, Vivek Kasireddy wrote:
> If the VMM's (Qemu) memory backend is backed up by memfd + Hugepages
> (hugetlbfs and not THP), we have to first find the hugepage(s) where
> the Guest allocations are located and then extract the regular 4k
> sized subpages from them.
> 
> v2: Ensure that the subpage and hugepage offsets are calculated correctly
> when the range of subpage allocations cuts across multiple hugepages.
> 
> v3: Instead of repeatedly looking up the hugepage for each subpage,
> only do it when the subpage allocation crosses over into a different
> hugepage. (suggested by Gerd and DW)
> 
> v4: Fix the following warning identified by checkpatch:
> CHECK:OPEN_ENDED_LINE: Lines should not end with a '('
> 
> Cc: Gerd Hoffmann <kraxel at redhat.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy at intel.com>
> Signed-off-by: Dongwon Kim <dongwon.kim at intel.com>

> +					hpage = find_get_page_flags(mapping,
> +							pgoff, FGP_ACCESSED);

checkpatch is still not happy.  Fixed that up & pushed to drm-misc-next.

thanks,
  Gerd