[PATCH 1/2] drm/amdgpu: fix start calculation in amdgpu_vram_mgr_new

[Alex Deucher]

On Tue, May 10, 2022 at 11:08 AM Christian König
<christian.koenig at amd.com> wrote:
>
> Am 10.05.22 um 16:42 schrieb Alex Deucher:
> > On Tue, May 10, 2022 at 7:36 AM Christian König
> > <ckoenig.leichtzumerken at gmail.com> wrote:
> >> We still need to calculate a virtual start address for the resource to
> >> aid checking of it is visible or not.
> > Does this fix a known issue or is it just something you noticed?
>
> Just something I've noticed. Judging from the bug reports we get large
> BAR systems are so common by now that only a few people are left where
> that actually matters.
>

If you add that to the commit message, the patch is:
Acked-by: Alex Deucher <alexander.deucher at amd.com>

> Christian.
>
> >
> >> Signed-off-by: Christian König <christian.koenig at amd.com>
> >> ---
> >>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 22 +++++++++++++-------
> >>   1 file changed, 14 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> >> index 49e4092f447f..51d9d3a4456c 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> >> @@ -496,16 +496,22 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
> >>                          list_splice_tail(trim_list, &vres->blocks);
> >>          }
> >>
> >> -       list_for_each_entry(block, &vres->blocks, link)
> >> -               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> >> +       vres->base.start = 0;
> >> +       list_for_each_entry(block, &vres->blocks, link) {
> >> +               unsigned long start;
> >>
> >> -       block = amdgpu_vram_mgr_first_block(&vres->blocks);
> >> -       if (!block) {
> >> -               r = -EINVAL;
> >> -               goto error_fini;
> >> -       }
> >> +               start = amdgpu_vram_mgr_block_start(block) +
> >> +                       amdgpu_vram_mgr_block_size(block);
> >> +               start >>= PAGE_SHIFT;
> >>
> >> -       vres->base.start = amdgpu_vram_mgr_block_start(block) >> PAGE_SHIFT;
> >> +               if (start > vres->base.num_pages)
> >> +                       start -= vres->base.num_pages;
> >> +               else
> >> +                       start = 0;
> >> +               vres->base.start = max(vres->base.start, start);
> >> +
> >> +               vis_usage += amdgpu_vram_mgr_vis_size(adev, block);
> >> +       }
> >>
> >>          if (amdgpu_is_vram_mgr_blocks_contiguous(&vres->blocks))
> >>                  vres->base.placement |= TTM_PL_FLAG_CONTIGUOUS;
> >> --
> >> 2.25.1
> >>
>