1 /*
2 * Copyright © 2017 Red Hat
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 (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 * Authors:
24 *
25 */
26 #ifndef __DRM_SYNCOBJ_H__
27 #define __DRM_SYNCOBJ_H__
28
29 #include "linux/dma-fence.h"
30
31 struct drm_syncobj_cb;
32
33 /**
34 * struct drm_syncobj - sync object.
35 *
36 * This structure defines a generic sync object which wraps a dma fence.
37 */
38 struct drm_syncobj {
39 /**
40 * @refcount:
41 *
42 * Reference count of this object.
43 */
44 struct kref refcount;
45 /**
46 * @fence:
47 * NULL or a pointer to the fence bound to this object.
48 *
49 * This field should not be used directly. Use drm_syncobj_fence_get
50 * and drm_syncobj_replace_fence instead.
51 */
52 struct dma_fence *fence;
53 /**
54 * @cb_list:
55 * List of callbacks to call when the fence gets replaced
56 */
57 struct list_head cb_list;
58 /**
59 * @lock:
60 * locks cb_list and write-locks fence.
61 */
62 spinlock_t lock;
63 /**
64 * @file:
65 * a file backing for this syncobj.
66 */
67 struct file *file;
68 };
69
70 typedef void (*drm_syncobj_func_t)(struct drm_syncobj *syncobj,
71 struct drm_syncobj_cb *cb);
72
73 /**
74 * struct drm_syncobj_cb - callback for drm_syncobj_add_callback
75 * @node: used by drm_syncob_add_callback to append this struct to
76 * syncobj::cb_list
77 * @func: drm_syncobj_func_t to call
78 *
79 * This struct will be initialized by drm_syncobj_add_callback, additional
80 * data can be passed along by embedding drm_syncobj_cb in another struct.
81 * The callback will get called the next time drm_syncobj_replace_fence is
82 * called.
83 */
84 struct drm_syncobj_cb {
85 struct list_head node;
86 drm_syncobj_func_t func;
87 };
88
89 void drm_syncobj_free(struct kref *kref);
90 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
91 struct dma_fence *fence);
92 int drm_syncobj_get_handle(struct drm_file *file_private,
93 struct drm_syncobj *syncobj, u32 *handle);
94 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
95
96 /**
97 * drm_syncobj_get - acquire a syncobj reference
98 * @obj: sync object
99 *
100 * This acquires additional reference to @obj. It is illegal to call this
101 * without already holding a reference. No locks required.
102 */
103 static inline void
drm_syncobj_get(struct drm_syncobj * obj)104 drm_syncobj_get(struct drm_syncobj *obj)
105 {
106 kref_get(&obj->refcount);
107 }
108
109 /**
110 * drm_syncobj_put - release a reference to a sync object.
111 * @obj: sync object.
112 */
113 static inline void
drm_syncobj_put(struct drm_syncobj * obj)114 drm_syncobj_put(struct drm_syncobj *obj)
115 {
116 kref_put(&obj->refcount, drm_syncobj_free);
117 }
118
119 static inline struct dma_fence *
drm_syncobj_fence_get(struct drm_syncobj * syncobj)120 drm_syncobj_fence_get(struct drm_syncobj *syncobj)
121 {
122 struct dma_fence *fence;
123
124 rcu_read_lock();
125 fence = dma_fence_get_rcu_safe(&syncobj->fence);
126 rcu_read_unlock();
127
128 return fence;
129 }
130
131 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
132 u32 handle);
133 void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
134 struct drm_syncobj_cb *cb,
135 drm_syncobj_func_t func);
136 void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
137 struct drm_syncobj_cb *cb);
138 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
139 struct dma_fence *fence);
140 int drm_syncobj_find_fence(struct drm_file *file_private,
141 u32 handle,
142 struct dma_fence **fence);
143
144 #endif
145