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30 * DRM synchronisation objects (syncobj) are a persistent objects,
31 * that contain an optional fence. The fence can be updated with a new
34 * syncobj's can be export to fd's and back, these fd's are opaque and
35 * have no other use case, except passing the syncobj between processes.
37 * Their primary use-case is to implement Vulkan fences and semaphores.
39 * syncobj have a kref reference count, but also have an optional file.
40 * The file is only created once the syncobj is exported.
41 * The file takes a reference on the kref.
45 #include <linux/file.h>
47 #include <linux/anon_inodes.h>
49 #include "drm_internal.h"
50 #include <drm/drm_syncobj.h>
53 * drm_syncobj_find - lookup and reference a sync object.
54 * @file_private: drm file private pointer
55 * @handle: sync object handle to lookup.
57 * Returns a reference to the syncobj pointed to by handle or NULL.
59 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
62 struct drm_syncobj *syncobj;
64 spin_lock(&file_private->syncobj_table_lock);
66 /* Check if we currently have a reference on the object */
67 syncobj = idr_find(&file_private->syncobj_idr, handle);
69 drm_syncobj_get(syncobj);
71 spin_unlock(&file_private->syncobj_table_lock);
75 EXPORT_SYMBOL(drm_syncobj_find);
78 * drm_syncobj_replace_fence - replace fence in a sync object.
79 * @file_private: drm file private pointer.
80 * @syncobj: Sync object to replace fence in
81 * @fence: fence to install in sync file.
83 * This replaces the fence on a sync object.
85 void drm_syncobj_replace_fence(struct drm_file *file_private,
86 struct drm_syncobj *syncobj,
87 struct dma_fence *fence)
89 struct dma_fence *old_fence = NULL;
93 old_fence = xchg(&syncobj->fence, fence);
95 dma_fence_put(old_fence);
97 EXPORT_SYMBOL(drm_syncobj_replace_fence);
99 int drm_syncobj_fence_get(struct drm_file *file_private,
101 struct dma_fence **fence)
103 struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
109 *fence = dma_fence_get(syncobj->fence);
113 drm_syncobj_put(syncobj);
116 EXPORT_SYMBOL(drm_syncobj_fence_get);
119 * drm_syncobj_free - free a sync object.
120 * @kref: kref to free.
122 * Only to be called from kref_put in drm_syncobj_put.
124 void drm_syncobj_free(struct kref *kref)
126 struct drm_syncobj *syncobj = container_of(kref,
129 dma_fence_put(syncobj->fence);
132 EXPORT_SYMBOL(drm_syncobj_free);
134 static int drm_syncobj_create(struct drm_file *file_private,
138 struct drm_syncobj *syncobj;
140 syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
144 kref_init(&syncobj->refcount);
146 idr_preload(GFP_KERNEL);
147 spin_lock(&file_private->syncobj_table_lock);
148 ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
149 spin_unlock(&file_private->syncobj_table_lock);
154 drm_syncobj_put(syncobj);
162 static int drm_syncobj_destroy(struct drm_file *file_private,
165 struct drm_syncobj *syncobj;
167 spin_lock(&file_private->syncobj_table_lock);
168 syncobj = idr_remove(&file_private->syncobj_idr, handle);
169 spin_unlock(&file_private->syncobj_table_lock);
174 drm_syncobj_put(syncobj);
178 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
180 struct drm_syncobj *syncobj = file->private_data;
182 drm_syncobj_put(syncobj);
186 static const struct file_operations drm_syncobj_file_fops = {
187 .release = drm_syncobj_file_release,
190 static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj)
192 struct file *file = anon_inode_getfile("syncobj_file",
193 &drm_syncobj_file_fops,
196 return PTR_ERR(file);
198 drm_syncobj_get(syncobj);
199 if (cmpxchg(&syncobj->file, NULL, file)) {
207 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
208 u32 handle, int *p_fd)
210 struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
217 fd = get_unused_fd_flags(O_CLOEXEC);
219 drm_syncobj_put(syncobj);
223 if (!syncobj->file) {
224 ret = drm_syncobj_alloc_file(syncobj);
228 fd_install(fd, syncobj->file);
229 drm_syncobj_put(syncobj);
234 drm_syncobj_put(syncobj);
238 static struct drm_syncobj *drm_syncobj_fdget(int fd)
240 struct file *file = fget(fd);
244 if (file->f_op != &drm_syncobj_file_fops)
247 return file->private_data;
253 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
256 struct drm_syncobj *syncobj = drm_syncobj_fdget(fd);
262 /* take a reference to put in the idr */
263 drm_syncobj_get(syncobj);
265 idr_preload(GFP_KERNEL);
266 spin_lock(&file_private->syncobj_table_lock);
267 ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
268 spin_unlock(&file_private->syncobj_table_lock);
280 * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
281 * @dev: drm_device which is being opened by userspace
282 * @file_private: drm file-private structure to set up
284 * Called at device open time, sets up the structure for handling refcounting
288 drm_syncobj_open(struct drm_file *file_private)
290 idr_init(&file_private->syncobj_idr);
291 spin_lock_init(&file_private->syncobj_table_lock);
295 drm_syncobj_release_handle(int id, void *ptr, void *data)
297 struct drm_syncobj *syncobj = ptr;
299 drm_syncobj_put(syncobj);
304 * drm_syncobj_release - release file-private sync object resources
305 * @dev: drm_device which is being closed by userspace
306 * @file_private: drm file-private structure to clean up
308 * Called at close time when the filp is going away.
310 * Releases any remaining references on objects by this filp.
313 drm_syncobj_release(struct drm_file *file_private)
315 idr_for_each(&file_private->syncobj_idr,
316 &drm_syncobj_release_handle, file_private);
317 idr_destroy(&file_private->syncobj_idr);
321 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
322 struct drm_file *file_private)
324 struct drm_syncobj_create *args = data;
326 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
329 /* no valid flags yet */
333 return drm_syncobj_create(file_private,
338 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
339 struct drm_file *file_private)
341 struct drm_syncobj_destroy *args = data;
343 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
346 /* make sure padding is empty */
349 return drm_syncobj_destroy(file_private, args->handle);
353 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
354 struct drm_file *file_private)
356 struct drm_syncobj_handle *args = data;
358 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
361 if (args->pad || args->flags)
364 return drm_syncobj_handle_to_fd(file_private, args->handle,
369 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
370 struct drm_file *file_private)
372 struct drm_syncobj_handle *args = data;
374 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
377 if (args->pad || args->flags)
380 return drm_syncobj_fd_to_handle(file_private, args->fd,