xref: /openbmc/linux/include/drm/drm_syncobj.h (revision a9ebfc40)
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 #include <linux/dma-fence-chain.h>
31 
32 struct drm_file;
33 
34 /**
35  * struct drm_syncobj - sync object.
36  *
37  * This structure defines a generic sync object which wraps a &dma_fence.
38  */
39 struct drm_syncobj {
40 	/**
41 	 * @refcount: Reference count of this object.
42 	 */
43 	struct kref refcount;
44 	/**
45 	 * @fence:
46 	 * NULL or a pointer to the fence bound to this object.
47 	 *
48 	 * This field should not be used directly. Use drm_syncobj_fence_get()
49 	 * and drm_syncobj_replace_fence() instead.
50 	 */
51 	struct dma_fence __rcu *fence;
52 	/**
53 	 * @cb_list: List of callbacks to call when the &fence gets replaced.
54 	 */
55 	struct list_head cb_list;
56 	/**
57 	 * @ev_fd_list: List of registered eventfd.
58 	 */
59 	struct list_head ev_fd_list;
60 	/**
61 	 * @lock: Protects &cb_list and &ev_fd_list, and write-locks &fence.
62 	 */
63 	spinlock_t lock;
64 	/**
65 	 * @file: A file backing for this syncobj.
66 	 */
67 	struct file *file;
68 };
69 
70 void drm_syncobj_free(struct kref *kref);
71 
72 /**
73  * drm_syncobj_get - acquire a syncobj reference
74  * @obj: sync object
75  *
76  * This acquires an additional reference to @obj. It is illegal to call this
77  * without already holding a reference. No locks required.
78  */
79 static inline void
80 drm_syncobj_get(struct drm_syncobj *obj)
81 {
82 	kref_get(&obj->refcount);
83 }
84 
85 /**
86  * drm_syncobj_put - release a reference to a sync object.
87  * @obj: sync object.
88  */
89 static inline void
90 drm_syncobj_put(struct drm_syncobj *obj)
91 {
92 	kref_put(&obj->refcount, drm_syncobj_free);
93 }
94 
95 /**
96  * drm_syncobj_fence_get - get a reference to a fence in a sync object
97  * @syncobj: sync object.
98  *
99  * This acquires additional reference to &drm_syncobj.fence contained in @obj,
100  * if not NULL. It is illegal to call this without already holding a reference.
101  * No locks required.
102  *
103  * Returns:
104  * Either the fence of @obj or NULL if there's none.
105  */
106 static inline struct dma_fence *
107 drm_syncobj_fence_get(struct drm_syncobj *syncobj)
108 {
109 	struct dma_fence *fence;
110 
111 	rcu_read_lock();
112 	fence = dma_fence_get_rcu_safe(&syncobj->fence);
113 	rcu_read_unlock();
114 
115 	return fence;
116 }
117 
118 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
119 				     u32 handle);
120 void drm_syncobj_add_point(struct drm_syncobj *syncobj,
121 			   struct dma_fence_chain *chain,
122 			   struct dma_fence *fence,
123 			   uint64_t point);
124 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
125 			       struct dma_fence *fence);
126 int drm_syncobj_find_fence(struct drm_file *file_private,
127 			   u32 handle, u64 point, u64 flags,
128 			   struct dma_fence **fence);
129 void drm_syncobj_free(struct kref *kref);
130 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
131 		       struct dma_fence *fence);
132 int drm_syncobj_get_handle(struct drm_file *file_private,
133 			   struct drm_syncobj *syncobj, u32 *handle);
134 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
135 
136 #endif
137