include/drm/drm_syncobj.h

0001 /*
0002  * Copyright © 2017 Red Hat
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice (including the next
0012  * paragraph) shall be included in all copies or substantial portions of the
0013  * Software.
0014  *
0015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0016  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0017  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0018  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
0019  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
0020  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
0021  * IN THE SOFTWARE.
0022  *
0023  * Authors:
0024  *
0025  */
0026 #ifndef __DRM_SYNCOBJ_H__
0027 #define __DRM_SYNCOBJ_H__
0028
0029 #include <linux/dma-fence.h>
0030 #include <linux/dma-fence-chain.h>
0031
0032 struct drm_file;
0033
0034 /**
0035  * struct drm_syncobj - sync object.
0036  *
0037  * This structure defines a generic sync object which wraps a &dma_fence.
0038  */
0039 struct drm_syncobj {
0040     /**
0041      * @refcount: Reference count of this object.
0042      */
0043     struct kref refcount;
0044     /**
0045      * @fence:
0046      * NULL or a pointer to the fence bound to this object.
0047      *
0048      * This field should not be used directly. Use drm_syncobj_fence_get()
0049      * and drm_syncobj_replace_fence() instead.
0050      */
0051     struct dma_fence __rcu *fence;
0052     /**
0053      * @cb_list: List of callbacks to call when the &fence gets replaced.
0054      */
0055     struct list_head cb_list;
0056     /**
0057      * @lock: Protects &cb_list and write-locks &fence.
0058      */
0059     spinlock_t lock;
0060     /**
0061      * @file: A file backing for this syncobj.
0062      */
0063     struct file *file;
0064 };
0065
0066 void drm_syncobj_free(struct kref *kref);
0067
0068 /**
0069  * drm_syncobj_get - acquire a syncobj reference
0070  * @obj: sync object
0071  *
0072  * This acquires an additional reference to @obj. It is illegal to call this
0073  * without already holding a reference. No locks required.
0074  */
0075 static inline void
0076 drm_syncobj_get(struct drm_syncobj *obj)
0077 {
0078     kref_get(&obj->refcount);
0079 }
0080
0081 /**
0082  * drm_syncobj_put - release a reference to a sync object.
0083  * @obj: sync object.
0084  */
0085 static inline void
0086 drm_syncobj_put(struct drm_syncobj *obj)
0087 {
0088     kref_put(&obj->refcount, drm_syncobj_free);
0089 }
0090
0091 /**
0092  * drm_syncobj_fence_get - get a reference to a fence in a sync object
0093  * @syncobj: sync object.
0094  *
0095  * This acquires additional reference to &drm_syncobj.fence contained in @obj,
0096  * if not NULL. It is illegal to call this without already holding a reference.
0097  * No locks required.
0098  *
0099  * Returns:
0100  * Either the fence of @obj or NULL if there's none.
0101  */
0102 static inline struct dma_fence *
0103 drm_syncobj_fence_get(struct drm_syncobj *syncobj)
0104 {
0105     struct dma_fence *fence;
0106
0107     rcu_read_lock();
0108     fence = dma_fence_get_rcu_safe(&syncobj->fence);
0109     rcu_read_unlock();
0110
0111     return fence;
0112 }
0113
0114 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
0115                      u32 handle);
0116 void drm_syncobj_add_point(struct drm_syncobj *syncobj,
0117                struct dma_fence_chain *chain,
0118                struct dma_fence *fence,
0119                uint64_t point);
0120 void drm_syncobj_replace_fence(struct drm_syncobj *syncobj,
0121                    struct dma_fence *fence);
0122 int drm_syncobj_find_fence(struct drm_file *file_private,
0123                u32 handle, u64 point, u64 flags,
0124                struct dma_fence **fence);
0125 void drm_syncobj_free(struct kref *kref);
0126 int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags,
0127                struct dma_fence *fence);
0128 int drm_syncobj_get_handle(struct drm_file *file_private,
0129                struct drm_syncobj *syncobj, u32 *handle);
0130 int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
0131
0132 #endif