drm/amdgpu: Revert "add spin lock to protect freed list in vm (v3)"

Not needed any more because we need to protect the elements on the list anyway.

This reverts commit dae6ecf9e6c9b677e577826c3ac665c6dd9c490b.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -971,22 +971,18 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
 	struct amdgpu_bo_va_mapping *mapping;
 	int r;
 
-	spin_lock(&vm->freed_lock);
 	while (!list_empty(&vm->freed)) {
 		mapping = list_first_entry(&vm->freed,
 			struct amdgpu_bo_va_mapping, list);
 		list_del(&mapping->list);
-		spin_unlock(&vm->freed_lock);
+
 		r = amdgpu_vm_bo_split_mapping(adev, NULL, 0, vm, mapping,
 					       0, NULL);
 		kfree(mapping);
 		if (r)
 			return r;
 
-		spin_lock(&vm->freed_lock);
 	}
-	spin_unlock(&vm->freed_lock);
-
 	return 0;
 
 }
@@ -1252,13 +1248,10 @@ int amdgpu_vm_bo_unmap(struct amdgpu_device *adev,
 	spin_unlock(&vm->it_lock);
 	trace_amdgpu_vm_bo_unmap(bo_va, mapping);
 
-	if (valid) {
-		spin_lock(&vm->freed_lock);
+	if (valid)
 		list_add(&mapping->list, &vm->freed);
-		spin_unlock(&vm->freed_lock);
-	} else {
+	else
 		kfree(mapping);
-	}
 
 	return 0;
 }
@@ -1291,9 +1284,7 @@ void amdgpu_vm_bo_rmv(struct amdgpu_device *adev,
 		interval_tree_remove(&mapping->it, &vm->va);
 		spin_unlock(&vm->it_lock);
 		trace_amdgpu_vm_bo_unmap(bo_va, mapping);
-		spin_lock(&vm->freed_lock);
 		list_add(&mapping->list, &vm->freed);
-		spin_unlock(&vm->freed_lock);
 	}
 	list_for_each_entry_safe(mapping, next, &bo_va->invalids, list) {
 		list_del(&mapping->list);
@@ -1357,7 +1348,6 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	INIT_LIST_HEAD(&vm->cleared);
 	INIT_LIST_HEAD(&vm->freed);
 	spin_lock_init(&vm->it_lock);
-	spin_lock_init(&vm->freed_lock);
 	pd_size = amdgpu_vm_directory_size(adev);
 	pd_entries = amdgpu_vm_num_pdes(adev);