[PATCH 4/5] drm/amdgpu: don't use ttm_bo_move_ttm in amdgpu_ttm_bind v2

[Chunming Zhou]

On 2017年10月27日 22:43, Christian König wrote:
> From: Christian König <christian.koenig at amd.com>
>
> Just allocate the GART space and fill it.
>
> This prevents forcing the BO to be idle.
>
> v2: don't unbind/bind at all, just fill the allocated GART space
Could you explain what 'unbind/bind' is? My old understanding is 'bind' 
is to filling gart space, isn't it?

one comment in line...
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 21 +++++++++++++++------
>   1 file changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index eead348..06871a9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -878,10 +878,12 @@ static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
>   int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>   {
>   	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
> +	struct amdgpu_ttm_tt *gtt = (void*)bo->ttm;
>   	struct ttm_mem_reg tmp;
>   
>   	struct ttm_placement placement;
>   	struct ttm_place placements;
> +	uint64_t flags;
>   	int r;
>   
>   	if (bo->mem.mem_type != TTM_PL_TT ||
> @@ -903,14 +905,21 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>   	if (unlikely(r))
>   		return r;
>   
> -	r = ttm_bo_move_ttm(bo, true, false, &tmp);
> -	if (unlikely(r))
> +	flags = amdgpu_ttm_tt_pte_flags(adev, bo->ttm, &tmp);
> +	gtt->offset = (u64)tmp.start << PAGE_SHIFT;
> +	r = amdgpu_gart_bind(adev, gtt->offset, bo->ttm->num_pages,
> +			     bo->ttm->pages, gtt->ttm.dma_address, flags);
> +	if (unlikely(r)) {
>   		ttm_bo_mem_put(bo, &tmp);
> -	else
> -		bo->offset = (bo->mem.start << PAGE_SHIFT) +
> -			bo->bdev->man[bo->mem.mem_type].gpu_offset;
> +		return r;
> +	}
>   
> -	return r;
> +	ttm_bo_mem_put(bo, &bo->mem);
The old node doesn't need to wait before put it? if another user 
allocate in same place immediately, doesn't it result in problem?

Regards,
David Zhou
> +	bo->mem = tmp;
> +	bo->offset = (bo->mem.start << PAGE_SHIFT) +
> +		bo->bdev->man[bo->mem.mem_type].gpu_offset;
> +
> +	return 0;
>   }
>   
>   int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo)