drm/amdgpu: drop unnecessary restriction for huge root PDEs

The root PD can also contain huge PDEs.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -120,23 +120,17 @@ static inline void amdgpu_vm_eviction_unlock(struct amdgpu_vm *vm)
 static unsigned amdgpu_vm_level_shift(struct amdgpu_device *adev,
 				      unsigned level)
 {
-	unsigned shift = 0xff;
-
 	switch (level) {
 	case AMDGPU_VM_PDB2:
 	case AMDGPU_VM_PDB1:
 	case AMDGPU_VM_PDB0:
-		shift = 9 * (AMDGPU_VM_PDB0 - level) +
+		return 9 * (AMDGPU_VM_PDB0 - level) +
 			adev->vm_manager.block_size;
-		break;
 	case AMDGPU_VM_PTB:
-		shift = 0;
-		break;
+		return 0;
 	default:
-		dev_err(adev->dev, "the level%d isn't supported.\n", level);
+		return ~0;
 	}
-
-	return shift;
 }
 
 /**
@@ -1458,13 +1452,6 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 
 		pt = cursor.entry->base.bo;
 
-		/* The root level can't be a huge page */
-		if (cursor.level == adev->vm_manager.root_level) {
-			if (!amdgpu_vm_pt_descendant(adev, &cursor))
-				return -ENOENT;
-			continue;
-		}
-
 		shift = amdgpu_vm_level_shift(adev, cursor.level);
 		parent_shift = amdgpu_vm_level_shift(adev, cursor.level - 1);
 		if (adev->asic_type < CHIP_VEGA10 &&
@@ -1483,11 +1470,9 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
 			if (!amdgpu_vm_pt_descendant(adev, &cursor))
 				return -ENOENT;
 			continue;
-		} else if (frag >= parent_shift &&
-			   cursor.level - 1 != adev->vm_manager.root_level) {
+		} else if (frag >= parent_shift) {
 			/* If the fragment size is even larger than the parent
-			 * shift we should go up one level and check it again
-			 * unless one level up is the root level.
+			 * shift we should go up one level and check it again.
 			 */
 			if (!amdgpu_vm_pt_ancestor(&cursor))
 				return -ENOENT;