[PATCH] drm/amdgpu: Mark amdgpu_bo as invalid after moved

[Huang, Trigger]

[AMD Official Use Only - AMD Internal Distribution Only]

This patch seems to be wrong.
Quite a lot of preparations have been done in amdgpu_bo_move_notify
For example, amdgpu_bo_kunmap() will be called to prevent the BO from being accessed by CPU. If not called, the CPU may attempt to access the BO while it is being moved.

Thanks,
Trigger

> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
> YuanShang
> Sent: Thursday, July 11, 2024 5:10 PM
> To: amd-gfx at lists.freedesktop.org
> Cc: YuanShang Mao (River) <YuanShang.Mao at amd.com>; YuanShang Mao
> (River) <YuanShang.Mao at amd.com>
> Subject: [PATCH] drm/amdgpu: Mark amdgpu_bo as invalid after moved
>
> Caution: This message originated from an External Source. Use proper caution
> when opening attachments, clicking links, or responding.
>
>
> It leads to race condition if amdgpu_bo is marked as invalid before it is really
> moved.
>
> Signed-off-by: YuanShang <YuanShang.Mao at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 29e4b5875872..a29d5132ad3d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -519,8 +519,8 @@ static int amdgpu_bo_move(struct ttm_buffer_object
> *bo, bool evict,
>
>         if (!old_mem || (old_mem->mem_type == TTM_PL_SYSTEM &&
>                          bo->ttm == NULL)) {
> -               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_bo_move_null(bo, new_mem);
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 return 0;
>         }
>         if (old_mem->mem_type == AMDGPU_GEM_DOMAIN_DGMA || @@ -
> 530,8 +530,8 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo,
> bool evict,
>         if (old_mem->mem_type == TTM_PL_SYSTEM &&
>             (new_mem->mem_type == TTM_PL_TT ||
>              new_mem->mem_type == AMDGPU_PL_PREEMPT)) {
> -               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_bo_move_null(bo, new_mem);
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 return 0;
>         }
>         if ((old_mem->mem_type == TTM_PL_TT || @@ -542,9 +542,9 @@ static
> int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
>                         return r;
>
>                 amdgpu_ttm_backend_unbind(bo->bdev, bo->ttm);
> -               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_resource_free(bo, &bo->resource);
>                 ttm_bo_assign_mem(bo, new_mem);
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 return 0;
>         }
>
> @@ -557,8 +557,8 @@ static int amdgpu_bo_move(struct ttm_buffer_object
> *bo, bool evict,
>             new_mem->mem_type == AMDGPU_PL_OA ||
>             new_mem->mem_type == AMDGPU_PL_DOORBELL) {
>                 /* Nothing to save here */
> -               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 ttm_bo_move_null(bo, new_mem);
> +               amdgpu_bo_move_notify(bo, evict, new_mem);
>                 return 0;
>         }
>
> @@ -583,11 +583,11 @@ static int amdgpu_bo_move(struct
> ttm_buffer_object *bo, bool evict,
>                 return -EMULTIHOP;
>         }
>
> -       amdgpu_bo_move_notify(bo, evict, new_mem);
>         if (adev->mman.buffer_funcs_enabled)
>                 r = amdgpu_move_blit(bo, evict, new_mem, old_mem);
>         else
>                 r = -ENODEV;
> +       amdgpu_bo_move_notify(bo, evict, new_mem);
>
>         if (r) {
>                 /* Check that all memory is CPU accessible */
> --
> 2.25.1