[PATCH 4/5] drm/nouveau: stop using TTMs fault callback

[Nirmoy]

Tested this on GeForce GT 710

Tested-by: Nirmoy Das <nirmoy.das at amd.com>


On 9/25/20 4:55 PM, Christian König wrote:
> We already implemented the fault handler ourself,
> just open code what is necessary here.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/nouveau/nouveau_bo.c  | 50 ++++++++++++++-------------
>   drivers/gpu/drm/nouveau/nouveau_bo.h  |  1 +
>   drivers/gpu/drm/nouveau/nouveau_ttm.c | 10 +++---
>   3 files changed, 33 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
> index 8d51cfca07c8..1d4b16c0e353 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_bo.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
> @@ -1226,8 +1226,7 @@ nouveau_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_resource *reg)
>   	mutex_unlock(&drm->ttm.io_reserve_mutex);
>   }
>   
> -static int
> -nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
> +vm_fault_t nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
>   {
>   	struct nouveau_drm *drm = nouveau_bdev(bo->bdev);
>   	struct nouveau_bo *nvbo = nouveau_bo(bo);
> @@ -1243,34 +1242,38 @@ nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo)
>   		    !nvbo->kind)
>   			return 0;
>   
> -		if (bo->mem.mem_type == TTM_PL_SYSTEM) {
> -			nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_GART,
> -						 0);
> +		if (bo->mem.mem_type != TTM_PL_SYSTEM)
> +			return 0;
> +
> +		nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_GART, 0);
> +
> +	} else {
> +		/* make sure bo is in mappable vram */
> +		if (drm->client.device.info.family >= NV_DEVICE_INFO_V0_TESLA ||
> +		    bo->mem.start + bo->mem.num_pages < mappable)
> +			return 0;
>   
> -			ret = nouveau_bo_validate(nvbo, false, false);
> -			if (ret)
> -				return ret;
> +		for (i = 0; i < nvbo->placement.num_placement; ++i) {
> +			nvbo->placements[i].fpfn = 0;
> +			nvbo->placements[i].lpfn = mappable;
>   		}
> -		return 0;
> -	}
>   
> -	/* make sure bo is in mappable vram */
> -	if (drm->client.device.info.family >= NV_DEVICE_INFO_V0_TESLA ||
> -	    bo->mem.start + bo->mem.num_pages < mappable)
> -		return 0;
> +		for (i = 0; i < nvbo->placement.num_busy_placement; ++i) {
> +			nvbo->busy_placements[i].fpfn = 0;
> +			nvbo->busy_placements[i].lpfn = mappable;
> +		}
>   
> -	for (i = 0; i < nvbo->placement.num_placement; ++i) {
> -		nvbo->placements[i].fpfn = 0;
> -		nvbo->placements[i].lpfn = mappable;
> +		nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_VRAM, 0);
>   	}
>   
> -	for (i = 0; i < nvbo->placement.num_busy_placement; ++i) {
> -		nvbo->busy_placements[i].fpfn = 0;
> -		nvbo->busy_placements[i].lpfn = mappable;
> -	}
> +	ret = nouveau_bo_validate(nvbo, false, false);
> +	if (unlikely(ret == -EBUSY || ret == -ERESTARTSYS))
> +		return VM_FAULT_NOPAGE;
> +	else if (unlikely(ret))
> +		return VM_FAULT_SIGBUS;
>   
> -	nouveau_bo_placement_set(nvbo, NOUVEAU_GEM_DOMAIN_VRAM, 0);
> -	return nouveau_bo_validate(nvbo, false, false);
> +	ttm_bo_move_to_lru_tail_unlocked(bo);
> +	return 0;
>   }
>   
>   static int
> @@ -1381,7 +1384,6 @@ struct ttm_bo_driver nouveau_bo_driver = {
>   	.move_notify = nouveau_bo_move_ntfy,
>   	.move = nouveau_bo_move,
>   	.verify_access = nouveau_bo_verify_access,
> -	.fault_reserve_notify = &nouveau_ttm_fault_reserve_notify,
>   	.io_mem_reserve = &nouveau_ttm_io_mem_reserve,
>   	.io_mem_free = &nouveau_ttm_io_mem_free,
>   };
> diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.h b/drivers/gpu/drm/nouveau/nouveau_bo.h
> index ff68ded8d590..641ef6298a0e 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_bo.h
> +++ b/drivers/gpu/drm/nouveau/nouveau_bo.h
> @@ -89,6 +89,7 @@ void nouveau_bo_placement_set(struct nouveau_bo *, u32 type, u32 busy);
>   void nouveau_bo_wr16(struct nouveau_bo *, unsigned index, u16 val);
>   u32  nouveau_bo_rd32(struct nouveau_bo *, unsigned index);
>   void nouveau_bo_wr32(struct nouveau_bo *, unsigned index, u32 val);
> +vm_fault_t nouveau_ttm_fault_reserve_notify(struct ttm_buffer_object *bo);
>   void nouveau_bo_fence(struct nouveau_bo *, struct nouveau_fence *, bool exclusive);
>   int  nouveau_bo_validate(struct nouveau_bo *, bool interruptible,
>   			 bool no_wait_gpu);
> diff --git a/drivers/gpu/drm/nouveau/nouveau_ttm.c b/drivers/gpu/drm/nouveau/nouveau_ttm.c
> index 427341753441..edf3bb89a47f 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_ttm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_ttm.c
> @@ -134,17 +134,19 @@ static vm_fault_t nouveau_ttm_fault(struct vm_fault *vmf)
>   	if (ret)
>   		return ret;
>   
> -	nouveau_bo_del_io_reserve_lru(bo);
> +	ret = nouveau_ttm_fault_reserve_notify(bo);
> +	if (ret)
> +		goto error_unlock;
>   
> +	nouveau_bo_del_io_reserve_lru(bo);
>   	prot = vm_get_page_prot(vma->vm_flags);
>   	ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);
> +	nouveau_bo_add_io_reserve_lru(bo);
>   	if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
>   		return ret;
>   
> -	nouveau_bo_add_io_reserve_lru(bo);
> -
> +error_unlock:
>   	dma_resv_unlock(bo->base.resv);
> -
>   	return ret;
>   }
>