[PATCH] drm/amdgpu: fix another potential cause of VM faults

[Felix Kuehling]

On 2018-01-24 08:59 AM, Christian König wrote:
> The root PD can be evicted directly after allocating it, just validate
> it on first use.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling at amd.com>

Regards,
  Felix

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 32 ++++++++++++--------------------
>  1 file changed, 12 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 6f7141168838..0df52cb1765b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -2241,12 +2241,12 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>  {
>  	const unsigned align = min(AMDGPU_VM_PTB_ALIGN_SIZE,
>  		AMDGPU_VM_PTE_COUNT(adev) * 8);
> +	uint64_t init_pde_value = 0, flags;
>  	unsigned ring_instance;
>  	struct amdgpu_ring *ring;
>  	struct drm_sched_rq *rq;
> +	unsigned long size;
>  	int r, i;
> -	u64 flags;
> -	uint64_t init_pde_value = 0;
>  
>  	vm->va = RB_ROOT_CACHED;
>  	for (i = 0; i < AMDGPU_MAX_VMHUBS; i++)
> @@ -2297,29 +2297,21 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>  		flags |= (AMDGPU_GEM_CREATE_NO_CPU_ACCESS |
>  				AMDGPU_GEM_CREATE_SHADOW);
>  
> -	r = amdgpu_bo_create(adev,
> -			     amdgpu_vm_bo_size(adev, adev->vm_manager.root_level),
> -			     align, true,
> -			     AMDGPU_GEM_DOMAIN_VRAM,
> -			     flags,
> -			     NULL, NULL, init_pde_value, &vm->root.base.bo);
> +	size = amdgpu_vm_bo_size(adev, adev->vm_manager.root_level);
> +	r = amdgpu_bo_create(adev, size, align, true, AMDGPU_GEM_DOMAIN_VRAM,
> +			     flags, NULL, NULL, init_pde_value,
> +			     &vm->root.base.bo);
>  	if (r)
>  		goto error_free_sched_entity;
>  
> +	r = amdgpu_bo_reserve(vm->root.base.bo, true);
> +	if (r)
> +		goto error_free_root;
> +
>  	vm->root.base.vm = vm;
>  	list_add_tail(&vm->root.base.bo_list, &vm->root.base.bo->va);
> -	INIT_LIST_HEAD(&vm->root.base.vm_status);
> -
> -	if (vm->use_cpu_for_update) {
> -		r = amdgpu_bo_reserve(vm->root.base.bo, false);
> -		if (r)
> -			goto error_free_root;
> -
> -		r = amdgpu_bo_kmap(vm->root.base.bo, NULL);
> -		amdgpu_bo_unreserve(vm->root.base.bo);
> -		if (r)
> -			goto error_free_root;
> -	}
> +	list_add_tail(&vm->root.base.vm_status, &vm->evicted);
> +	amdgpu_bo_unreserve(vm->root.base.bo);
>  
>  	if (pasid) {
>  		unsigned long flags;