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
 32struct 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 */
 39struct 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
 70void 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 */
 79static inline void
 80drm_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 */
 89static inline void
 90drm_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 */
106static inline struct dma_fence *
107drm_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
118struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
119				     u32 handle);
120void drm_syncobj_add_point(struct drm_syncobj *syncobj,
121			   struct dma_fence_chain *chain,
122			   struct dma_fence *fence,
123			   uint64_t point);
124void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
125			       struct dma_fence *fence);
126int drm_syncobj_find_fence(struct drm_file *file_private,
127			   u32 handle, u64 point, u64 flags,
128			   struct dma_fence **fence);
129void drm_syncobj_free(struct kref *kref);
130int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
131		       struct dma_fence *fence);
132int drm_syncobj_get_handle(struct drm_file *file_private,
133			   struct drm_syncobj *syncobj, u32 *handle);
134int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
135
136#endif