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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>
48 #include <linux/sync_file.h>
50 #include "drm_internal.h"
51 #include <drm/drm_syncobj.h>
54 * drm_syncobj_find - lookup and reference a sync object.
55 * @file_private: drm file private pointer
56 * @handle: sync object handle to lookup.
58 * Returns a reference to the syncobj pointed to by handle or NULL.
60 struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private,
63 struct drm_syncobj *syncobj;
65 spin_lock(&file_private->syncobj_table_lock);
67 /* Check if we currently have a reference on the object */
68 syncobj = idr_find(&file_private->syncobj_idr, handle);
70 drm_syncobj_get(syncobj);
72 spin_unlock(&file_private->syncobj_table_lock);
76 EXPORT_SYMBOL(drm_syncobj_find);
79 * drm_syncobj_replace_fence - replace fence in a sync object.
80 * @file_private: drm file private pointer.
81 * @syncobj: Sync object to replace fence in
82 * @fence: fence to install in sync file.
84 * This replaces the fence on a sync object.
86 void drm_syncobj_replace_fence(struct drm_file *file_private,
87 struct drm_syncobj *syncobj,
88 struct dma_fence *fence)
90 struct dma_fence *old_fence = NULL;
94 old_fence = xchg(&syncobj->fence, fence);
96 dma_fence_put(old_fence);
98 EXPORT_SYMBOL(drm_syncobj_replace_fence);
100 int drm_syncobj_fence_get(struct drm_file *file_private,
102 struct dma_fence **fence)
104 struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
110 *fence = dma_fence_get(syncobj->fence);
114 drm_syncobj_put(syncobj);
117 EXPORT_SYMBOL(drm_syncobj_fence_get);
120 * drm_syncobj_free - free a sync object.
121 * @kref: kref to free.
123 * Only to be called from kref_put in drm_syncobj_put.
125 void drm_syncobj_free(struct kref *kref)
127 struct drm_syncobj *syncobj = container_of(kref,
130 dma_fence_put(syncobj->fence);
133 EXPORT_SYMBOL(drm_syncobj_free);
135 static int drm_syncobj_create(struct drm_file *file_private,
139 struct drm_syncobj *syncobj;
141 syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL);
145 kref_init(&syncobj->refcount);
147 idr_preload(GFP_KERNEL);
148 spin_lock(&file_private->syncobj_table_lock);
149 ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
150 spin_unlock(&file_private->syncobj_table_lock);
155 drm_syncobj_put(syncobj);
163 static int drm_syncobj_destroy(struct drm_file *file_private,
166 struct drm_syncobj *syncobj;
168 spin_lock(&file_private->syncobj_table_lock);
169 syncobj = idr_remove(&file_private->syncobj_idr, handle);
170 spin_unlock(&file_private->syncobj_table_lock);
175 drm_syncobj_put(syncobj);
179 static int drm_syncobj_file_release(struct inode *inode, struct file *file)
181 struct drm_syncobj *syncobj = file->private_data;
183 drm_syncobj_put(syncobj);
187 static const struct file_operations drm_syncobj_file_fops = {
188 .release = drm_syncobj_file_release,
191 static int drm_syncobj_alloc_file(struct drm_syncobj *syncobj)
193 struct file *file = anon_inode_getfile("syncobj_file",
194 &drm_syncobj_file_fops,
197 return PTR_ERR(file);
199 drm_syncobj_get(syncobj);
200 if (cmpxchg(&syncobj->file, NULL, file)) {
208 static int drm_syncobj_handle_to_fd(struct drm_file *file_private,
209 u32 handle, int *p_fd)
211 struct drm_syncobj *syncobj = drm_syncobj_find(file_private, handle);
218 fd = get_unused_fd_flags(O_CLOEXEC);
220 drm_syncobj_put(syncobj);
224 if (!syncobj->file) {
225 ret = drm_syncobj_alloc_file(syncobj);
229 fd_install(fd, syncobj->file);
230 drm_syncobj_put(syncobj);
235 drm_syncobj_put(syncobj);
239 static struct drm_syncobj *drm_syncobj_fdget(int fd)
241 struct file *file = fget(fd);
245 if (file->f_op != &drm_syncobj_file_fops)
248 return file->private_data;
254 static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
257 struct drm_syncobj *syncobj = drm_syncobj_fdget(fd);
263 /* take a reference to put in the idr */
264 drm_syncobj_get(syncobj);
266 idr_preload(GFP_KERNEL);
267 spin_lock(&file_private->syncobj_table_lock);
268 ret = idr_alloc(&file_private->syncobj_idr, syncobj, 1, 0, GFP_NOWAIT);
269 spin_unlock(&file_private->syncobj_table_lock);
280 int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
283 struct dma_fence *fence = sync_file_get_fence(fd);
284 struct drm_syncobj *syncobj;
289 syncobj = drm_syncobj_find(file_private, handle);
291 dma_fence_put(fence);
295 drm_syncobj_replace_fence(file_private, syncobj, fence);
296 dma_fence_put(fence);
297 drm_syncobj_put(syncobj);
301 int drm_syncobj_export_sync_file(struct drm_file *file_private,
302 int handle, int *p_fd)
305 struct dma_fence *fence;
306 struct sync_file *sync_file;
307 int fd = get_unused_fd_flags(O_CLOEXEC);
312 ret = drm_syncobj_fence_get(file_private, handle, &fence);
316 sync_file = sync_file_create(fence);
318 dma_fence_put(fence);
325 fd_install(fd, sync_file->file);
334 * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
335 * @dev: drm_device which is being opened by userspace
336 * @file_private: drm file-private structure to set up
338 * Called at device open time, sets up the structure for handling refcounting
342 drm_syncobj_open(struct drm_file *file_private)
344 idr_init(&file_private->syncobj_idr);
345 spin_lock_init(&file_private->syncobj_table_lock);
349 drm_syncobj_release_handle(int id, void *ptr, void *data)
351 struct drm_syncobj *syncobj = ptr;
353 drm_syncobj_put(syncobj);
358 * drm_syncobj_release - release file-private sync object resources
359 * @dev: drm_device which is being closed by userspace
360 * @file_private: drm file-private structure to clean up
362 * Called at close time when the filp is going away.
364 * Releases any remaining references on objects by this filp.
367 drm_syncobj_release(struct drm_file *file_private)
369 idr_for_each(&file_private->syncobj_idr,
370 &drm_syncobj_release_handle, file_private);
371 idr_destroy(&file_private->syncobj_idr);
375 drm_syncobj_create_ioctl(struct drm_device *dev, void *data,
376 struct drm_file *file_private)
378 struct drm_syncobj_create *args = data;
380 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
383 /* no valid flags yet */
387 return drm_syncobj_create(file_private,
392 drm_syncobj_destroy_ioctl(struct drm_device *dev, void *data,
393 struct drm_file *file_private)
395 struct drm_syncobj_destroy *args = data;
397 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
400 /* make sure padding is empty */
403 return drm_syncobj_destroy(file_private, args->handle);
407 drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
408 struct drm_file *file_private)
410 struct drm_syncobj_handle *args = data;
412 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
418 if (args->flags != 0 &&
419 args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
422 if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
423 return drm_syncobj_export_sync_file(file_private, args->handle,
426 return drm_syncobj_handle_to_fd(file_private, args->handle,
431 drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
432 struct drm_file *file_private)
434 struct drm_syncobj_handle *args = data;
436 if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
442 if (args->flags != 0 &&
443 args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
446 if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
447 return drm_syncobj_import_sync_file_fence(file_private,
451 return drm_syncobj_fd_to_handle(file_private, args->fd,