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: Reference count of this object.
41 */
42 struct kref refcount;
43 /**
44 * @fence:
45 * NULL or a pointer to the fence bound to this object.
46 *
47 * This field should not be used directly. Use drm_syncobj_fence_get()
48 * and drm_syncobj_replace_fence() instead.
49 */
50 struct dma_fence __rcu *fence;
51 /**
52 * @cb_list: List of callbacks to call when the &fence gets replaced.
53 */
54 struct list_head cb_list;
55 /**
56 * @lock: Protects &cb_list and write-locks &fence.
57 */
58 spinlock_t lock;
59 /**
60 * @file: A file backing for this syncobj.
61 */
62 struct file *file;
63 };
64
65 typedef void (*drm_syncobj_func_t)(struct drm_syncobj *syncobj,
66 struct drm_syncobj_cb *cb);
67
68 /**
69 * struct drm_syncobj_cb - callback for drm_syncobj_add_callback
70 * @node: used by drm_syncob_add_callback to append this struct to
71 * &drm_syncobj.cb_list
72 * @func: drm_syncobj_func_t to call
73 *
74 * This struct will be initialized by drm_syncobj_add_callback, additional
75 * data can be passed along by embedding drm_syncobj_cb in another struct.
76 * The callback will get called the next time drm_syncobj_replace_fence is
77 * called.
78 */
79 struct drm_syncobj_cb {
80 struct list_head node;
81 drm_syncobj_func_t func;
82 };
83
84 void drm_syncobj_free(struct kref *kref);
85
86 /**
87 * drm_syncobj_get - acquire a syncobj reference
88 * @obj: sync object
89 *
90 * This acquires an additional reference to @obj. It is illegal to call this
91 * without already holding a reference. No locks required.
92 */
93 static inline void
drm_syncobj_get(struct drm_syncobj * obj)94 drm_syncobj_get(struct drm_syncobj *obj)
95 {
96 kref_get(&obj->refcount);
97 }
98
99 /**
100 * drm_syncobj_put - release a reference to a sync object.
101 * @obj: sync object.
102 */
103 static inline void
drm_syncobj_put(struct drm_syncobj * obj)104 drm_syncobj_put(struct drm_syncobj *obj)
105 {
106 kref_put(&obj->refcount, drm_syncobj_free);
107 }
108
109 /**
110 * drm_syncobj_fence_get - get a reference to a fence in a sync object
111 * @syncobj: sync object.
112 *
113 * This acquires additional reference to &drm_syncobj.fence contained in @obj,
114 * if not NULL. It is illegal to call this without already holding a reference.
115 * No locks required.
116 *
117 * Returns:
118 * Either the fence of @obj or NULL if there's none.
119 */
120 static inline struct dma_fence *
drm_syncobj_fence_get(struct drm_syncobj * syncobj)121 drm_syncobj_fence_get(struct drm_syncobj *syncobj)
122 {
123 struct dma_fence *fence;
124
125 rcu_read_lock();
126 fence = dma_fence_get_rcu_safe(&syncobj->fence);
127 rcu_read_unlock();
128
129 return fence;
130 }
131
132 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
133 u32 handle);
134 void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
135 struct drm_syncobj_cb *cb,
136 drm_syncobj_func_t func);
137 void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
138 struct drm_syncobj_cb *cb);
139 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
140 struct dma_fence *fence);
141 int drm_syncobj_find_fence(struct drm_file *file_private,
142 u32 handle,
143 struct dma_fence **fence);
144 void drm_syncobj_free(struct kref *kref);
145 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
146 struct dma_fence *fence);
147 int drm_syncobj_get_handle(struct drm_file *file_private,
148 struct drm_syncobj *syncobj, u32 *handle);
149 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
150
151 #endif
152