1/*
2 * Copyright 2018 Advanced Micro Devices, Inc.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
21 *
22 *
23 */
24
25#ifndef _TTM_BO_INTERNAL_H_
26#define _TTM_BO_INTERNAL_H_
27
28#include <drm/ttm/ttm_bo.h>
29
30/**
31 * ttm_bo_get - reference a struct ttm_buffer_object
32 *
33 * @bo: The buffer object.
34 */
35static inline void ttm_bo_get(struct ttm_buffer_object *bo)
36{
37 kref_get(kref: &bo->kref);
38}
39
40/**
41 * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless
42 * its refcount has already reached zero.
43 * @bo: The buffer object.
44 *
45 * Used to reference a TTM buffer object in lookups where the object is removed
46 * from the lookup structure during the destructor and for RCU lookups.
47 *
48 * Returns: @bo if the referencing was successful, NULL otherwise.
49 */
50static inline __must_check struct ttm_buffer_object *
51ttm_bo_get_unless_zero(struct ttm_buffer_object *bo)
52{
53 if (!kref_get_unless_zero(kref: &bo->kref))
54 return NULL;
55 return bo;
56}
57
58void ttm_bo_put(struct ttm_buffer_object *bo);
59
60#endif
61

source code of linux/drivers/gpu/drm/ttm/ttm_bo_internal.h