include/drm/drm_syncobj.h

   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
  91 /**
  92  * drm_syncobj_get - acquire a syncobj reference
  93  * @obj: sync object
  94  *
  95  * This acquires additional reference to @obj. It is illegal to call this
  96  * without already holding a reference. No locks required.
  97  */
  98 static inline void
  99 drm_syncobj_get(struct drm_syncobj *obj)
 100 {
 101         kref_get(&obj->refcount);
 102 }
 103
 104 /**
 105  * drm_syncobj_put - release a reference to a sync object.
 106  * @obj: sync object.
 107  */
 108 static inline void
 109 drm_syncobj_put(struct drm_syncobj *obj)
 110 {
 111         kref_put(&obj->refcount, drm_syncobj_free);
 112 }
 113
 114 static inline struct dma_fence *
 115 drm_syncobj_fence_get(struct drm_syncobj *syncobj)
 116 {
 117         struct dma_fence *fence;
 118
 119         rcu_read_lock();
 120         fence = dma_fence_get_rcu_safe(&syncobj->fence);
 121         rcu_read_unlock();
 122
 123         return fence;
 124 }
 125
 126 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
 127                                      u32 handle);
 128 void drm_syncobj_add_callback(struct drm_syncobj *syncobj,
 129                               struct drm_syncobj_cb *cb,
 130                               drm_syncobj_func_t func);
 131 void drm_syncobj_remove_callback(struct drm_syncobj *syncobj,
 132                                  struct drm_syncobj_cb *cb);
 133 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
 134                                struct dma_fence *fence);
 135 int drm_syncobj_find_fence(struct drm_file *file_private,
 136                            u32 handle,
 137                            struct dma_fence **fence);
 138 void drm_syncobj_free(struct kref *kref);
 139
 140 #endif