[PATCH 2/2] drm/amdgpu/dma_buf: fix page_link check

[Alex Deucher]

Applied.  Thanks!

On Mon, Apr 7, 2025 at 10:42 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 07.04.25 um 16:18 schrieb Matthew Auld:
> > The page_link lower bits of the first sg could contain something like
> > SG_END, if we are mapping a single VRAM page or contiguous blob which
> > fits into one sg entry. Rather pull out the struct page, and use that in
> > our check to know if we mapped struct pages vs VRAM.
> >
> > Fixes: f44ffd677fb3 ("drm/amdgpu: add support for exporting VRAM using DMA-buf v3")
> > Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> > Cc: Christian König <christian.koenig at amd.com>
> > Cc: amd-gfx at lists.freedesktop.org
> > Cc: <stable at vger.kernel.org> # v5.8+
>
> Good point, haven't thought about that at all since we only abuse the sg table as DMA addr container.
>
> Reviewed-by: Christian König <christian.koenig at amd.com>
>
> Were is patch #1 from this series?
>
> Thanks,
> Christian.
>
> > ---
> >  drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> > index 9f627caedc3f..c9842a0e2a1c 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> > @@ -184,7 +184,7 @@ static void amdgpu_dma_buf_unmap(struct dma_buf_attachment *attach,
> >                                struct sg_table *sgt,
> >                                enum dma_data_direction dir)
> >  {
> > -     if (sgt->sgl->page_link) {
> > +     if (sg_page(sgt->sgl)) {
> >               dma_unmap_sgtable(attach->dev, sgt, dir, 0);
> >               sg_free_table(sgt);
> >               kfree(sgt);
>