[PATCH] drm/amdgpu: add VM update fences back to the root PD

[Tom St Denis]

This doesn't apply on top of 7fd3b632e17e55c5ffd008f9f025754e7daa1b66 
which is the tip of drm-next


Tom

On 2020-02-19 9:20 a.m., Christian König wrote:
> Add update fences to the root PD while mapping BOs.
>
> Otherwise PDs freed during the mapping won't wait for
> updates to finish and can cause corruptions.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 14 ++++++++++++--
>   1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index e7ab0c1e2793..dd63ccdbad2a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -585,8 +585,8 @@ void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
>   {
>   	entry->priority = 0;
>   	entry->tv.bo = &vm->root.base.bo->tbo;
> -	/* One for TTM and one for the CS job */
> -	entry->tv.num_shared = 2;
> +	/* Two for VM updates, one for TTM and one for the CS job */
> +	entry->tv.num_shared = 4;
>   	entry->user_pages = NULL;
>   	list_add(&entry->tv.head, validated);
>   }
> @@ -1619,6 +1619,16 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
>   		goto error_unlock;
>   	}
>   
> +	if (flags & AMDGPU_PTE_VALID) {
> +		struct amdgpu_bo *root = vm->root.base.bo;
> +
> +		if (!dma_fence_is_signaled(vm->last_direct))
> +			amdgpu_bo_fence(root, vm->last_direct, true);
> +
> +		if (!dma_fence_is_signaled(vm->last_delayed))
> +			amdgpu_bo_fence(root, vm->last_delayed, true);
> +	}
> +
>   	r = vm->update_funcs->prepare(&params, resv, sync_mode);
>   	if (r)
>   		goto error_unlock;