1 /* $NetBSD: drm_syncobj.h,v 1.2 2021/12/18 23:45:46 riastradh Exp $ */
2
3 /*
4 * Copyright © 2017 Red Hat
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 *
25 * Authors:
26 *
27 */
28 #ifndef __DRM_SYNCOBJ_H__
29 #define __DRM_SYNCOBJ_H__
30
31 #include <linux/dma-fence.h>
32 #include <linux/dma-fence-chain.h>
33
34 struct drm_file;
35
36 /**
37 * struct drm_syncobj - sync object.
38 *
39 * This structure defines a generic sync object which wraps a &dma_fence.
40 */
41 struct drm_syncobj {
42 /**
43 * @refcount: Reference count of this object.
44 */
45 struct kref refcount;
46 /**
47 * @fence:
48 * NULL or a pointer to the fence bound to this object.
49 *
50 * This field should not be used directly. Use drm_syncobj_fence_get()
51 * and drm_syncobj_replace_fence() instead.
52 */
53 struct dma_fence __rcu *fence;
54 /**
55 * @cb_list: List of callbacks to call when the &fence gets replaced.
56 */
57 struct list_head cb_list;
58 /**
59 * @lock: Protects &cb_list and write-locks &fence.
60 */
61 spinlock_t lock;
62 /**
63 * @file: A file backing for this syncobj.
64 */
65 struct file *file;
66 };
67
68 void drm_syncobj_free(struct kref *kref);
69
70 /**
71 * drm_syncobj_get - acquire a syncobj reference
72 * @obj: sync object
73 *
74 * This acquires an additional reference to @obj. It is illegal to call this
75 * without already holding a reference. No locks required.
76 */
77 static inline void
drm_syncobj_get(struct drm_syncobj * obj)78 drm_syncobj_get(struct drm_syncobj *obj)
79 {
80 kref_get(&obj->refcount);
81 }
82
83 /**
84 * drm_syncobj_put - release a reference to a sync object.
85 * @obj: sync object.
86 */
87 static inline void
drm_syncobj_put(struct drm_syncobj * obj)88 drm_syncobj_put(struct drm_syncobj *obj)
89 {
90 kref_put(&obj->refcount, drm_syncobj_free);
91 }
92
93 /**
94 * drm_syncobj_fence_get - get a reference to a fence in a sync object
95 * @syncobj: sync object.
96 *
97 * This acquires additional reference to &drm_syncobj.fence contained in @obj,
98 * if not NULL. It is illegal to call this without already holding a reference.
99 * No locks required.
100 *
101 * Returns:
102 * Either the fence of @obj or NULL if there's none.
103 */
104 static inline struct dma_fence *
drm_syncobj_fence_get(struct drm_syncobj * syncobj)105 drm_syncobj_fence_get(struct drm_syncobj *syncobj)
106 {
107 struct dma_fence *fence;
108
109 rcu_read_lock();
110 fence = dma_fence_get_rcu_safe(&syncobj->fence);
111 rcu_read_unlock();
112
113 return fence;
114 }
115
116 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
117 u32 handle);
118 void drm_syncobj_add_point(struct drm_syncobj *syncobj,
119 struct dma_fence_chain *chain,
120 struct dma_fence *fence,
121 uint64_t point);
122 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
123 struct dma_fence *fence);
124 int drm_syncobj_find_fence(struct drm_file *file_private,
125 u32 handle, u64 point, u64 flags,
126 struct dma_fence **fence);
127 void drm_syncobj_free(struct kref *kref);
128 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
129 struct dma_fence *fence);
130 int drm_syncobj_get_handle(struct drm_file *file_private,
131 struct drm_syncobj *syncobj, u32 *handle);
132 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
133
134 #endif
135