Re: [PATCH v2 1/4] drm/amdgpu: Use cursor start instead of ttm resource start

[Christian König <christian.koenig@xxxxxxx>]

Am 25.01.23 um 11:48 schrieb Somalapuram Amaranath:
> cleanup PAGE_SHIFT operation and replacing
> ttm_resource resource->start with cursor start
> using amdgpu_res_first API.
> v1 -> v2: reorder patch sequence
>
> Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 11 ++++++++---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 10 +++++++---
>   2 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 25a68d8888e0..2ab67ab204df 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -1346,6 +1346,7 @@ vm_fault_t amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo)
>   	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
>   	struct ttm_operation_ctx ctx = { false, false };
>   	struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
> +	struct amdgpu_res_cursor cursor;
>   	unsigned long offset;
>   	int r;
>   
> @@ -1355,7 +1356,8 @@ vm_fault_t amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo)
>   	if (bo->resource->mem_type != TTM_PL_VRAM)
>   		return 0;
>   
> -	offset = bo->resource->start << PAGE_SHIFT;
> +	amdgpu_res_first(bo->resource, 0, bo->resource->size, &cursor);
> +	offset = cursor.start;

That won't work like this. We use a virtual resource start for this 
check here.

>   	if ((offset + bo->base.size) <= adev->gmc.visible_vram_size)
>   		return 0;

Just replace this whole test with calling amdgpu_bo_in_cpu_visible_vram().

>   
> @@ -1378,7 +1380,8 @@ vm_fault_t amdgpu_bo_fault_reserve_notify(struct ttm_buffer_object *bo)
>   	else if (unlikely(r))
>   		return VM_FAULT_SIGBUS;
>   
> -	offset = bo->resource->start << PAGE_SHIFT;
> +	amdgpu_res_first(bo->resource, 0, bo->resource->size, &cursor);
> +	offset = cursor.start;
>   	/* this should never happen */
>   	if (bo->resource->mem_type == TTM_PL_VRAM &&
>   	    (offset + bo->base.size) > adev->gmc.visible_vram_size)

Same here, just call amdgpu_bo_in_cpu_visible_vram() instead.

> @@ -1491,9 +1494,11 @@ u64 amdgpu_bo_gpu_offset(struct amdgpu_bo *bo)
>   u64 amdgpu_bo_gpu_offset_no_check(struct amdgpu_bo *bo)
>   {
>   	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +	struct amdgpu_res_cursor cursor;
>   	uint64_t offset;
>   
> -	offset = (bo->tbo.resource->start << PAGE_SHIFT) +
> +	amdgpu_res_first(bo->tbo.resource, 0, bo->tbo.resource->size, &cursor);
> +	offset = cursor.start +
>   		 amdgpu_ttm_domain_start(adev, bo->tbo.resource->mem_type);
>   
>   	return amdgpu_gmc_sign_extend(offset);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index c5ef7f7bdc15..ffe6a1ab7f9a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -849,6 +849,7 @@ static int amdgpu_ttm_backend_bind(struct ttm_device *bdev,
>   {
>   	struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
>   	struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
> +	struct amdgpu_res_cursor cursor;
>   	uint64_t flags;
>   	int r;
>   
> @@ -896,7 +897,8 @@ static int amdgpu_ttm_backend_bind(struct ttm_device *bdev,
>   	flags = amdgpu_ttm_tt_pte_flags(adev, ttm, bo_mem);
>   
>   	/* bind pages into GART page tables */
> -	gtt->offset = (u64)bo_mem->start << PAGE_SHIFT;
> +	amdgpu_res_first(bo_mem, 0, bo_mem->size, &cursor);
> +	gtt->offset = cursor.start;
>   	amdgpu_gart_bind(adev, gtt->offset, ttm->num_pages,
>   			 gtt->ttm.dma_address, flags);
>   	gtt->bound = true;
> @@ -916,6 +918,7 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>   	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
>   	struct ttm_operation_ctx ctx = { false, false };
>   	struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(bo->ttm);
> +	struct amdgpu_res_cursor cursor;
>   	struct ttm_placement placement;
>   	struct ttm_place placements;
>   	struct ttm_resource *tmp;
> @@ -927,7 +930,7 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>   
>   	addr = amdgpu_gmc_agp_addr(bo);
>   	if (addr != AMDGPU_BO_INVALID_OFFSET) {
> -		bo->resource->start = addr >> PAGE_SHIFT;
> +		bo->resource->start = addr;

This doesn't belong into this patch and would break if only this patch 
is applied.

Please move it into a later patch.

Apart from those comments that looks good now,
Christian.

>   		return 0;
>   	}
>   
> @@ -949,7 +952,8 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
>   	flags = amdgpu_ttm_tt_pte_flags(adev, bo->ttm, tmp);
>   
>   	/* Bind pages */
> -	gtt->offset = (u64)tmp->start << PAGE_SHIFT;
> +	amdgpu_res_first(tmp, 0, tmp->size, &cursor);
> +	gtt->offset = cursor.start;
>   	amdgpu_ttm_gart_bind(adev, bo, flags);
>   	amdgpu_gart_invalidate_tlb(adev);
>   	ttm_resource_free(bo, &bo->resource);