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: 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
  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
 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 *
 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