3  * Parts ported from amdgpu (fence wait code).
41  *  - Import and export a syncobj's underlying fence to/from a sync file
42  *  - Reset a syncobj (set its fence to NULL)
43  *  - Signal a syncobj (set a trivially signaled fence)
44  *  - Wait for a syncobj's fence to appear and be signaled
57  * to an already signaled fence depending on whether the
63  * the syncobj, the syncobj's fence is replaced with a fence which will be
67  * struct &dma_fence_chain pointing to the DRM driver's fence and also
68  * pointing to the previous fence that was in the syncobj. The new struct
69  * &dma_fence_chain fence replace the syncobj's fence and will be signaled by
71  * fence previously in the syncobj.
74  * time the work is enqueued, it waits on the syncobj's fence before
75  * submitting the work to hardware. That fence is either :
77  *    - The syncobj's current fence if the syncobj is considered as a binary
82  * If the syncobj's fence is NULL or not present in the syncobj's timeline,
85  * With binary syncobj, all manipulation of the syncobjs's fence happens in
86  * terms of the current fence at the time the ioctl is called by userspace
91  * setting its pointer to a fence which is already signaled.
93  * With a timeline syncobj, all manipulation of the synobj's fence happens in
104  * syncobj's fence when signaling).
114  * Otherwise, it returns once at least one syncobj fence has been signaled
115  * and the index of a signaled fence is written back to the client.
118  * fence in a syncobj, if &DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT is set,
120  * fence and then wait on that fence.
122  * syncobjs in the array has a NULL fence, -EINVAL will be returned.
123  * Assuming the syncobj starts off with a NULL fence, this allows a client
127  * This requirement is inherited from the Vulkan fence API.
134  * fence to materialize on the timeline without waiting for the fence to be
167  * import/export the syncobj's current fence from/to a &sync_file.
169  * sycnobj's fence at the time of export and any later signal or reset
171  * When a sync file is imported into a syncobj, the syncobj's fence is set
172  * to the fence wrapped by that sync file.
187  * point 0 to mean take/replace the fence in the syncobj.
191 #include <linux/dma-fence-unwrap.h>
212 	struct dma_fence *fence;  member
222 	struct dma_fence *fence;  member
263 	struct dma_fence *fence;  in drm_syncobj_fence_add_wait()  local
265 	if (wait->fence)  in drm_syncobj_fence_add_wait()
269 	/* We've already tried once to get a fence and failed.  Now that we  in drm_syncobj_fence_add_wait()
271 	 * callback when a fence has already been set.  in drm_syncobj_fence_add_wait()
273 	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));  in drm_syncobj_fence_add_wait()
274 	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {  in drm_syncobj_fence_add_wait()
275 		dma_fence_put(fence);  in drm_syncobj_fence_add_wait()
277 	} else if (!fence) {  in drm_syncobj_fence_add_wait()
278 		wait->fence = dma_fence_get_stub();  in drm_syncobj_fence_add_wait()
280 		wait->fence = fence;  in drm_syncobj_fence_add_wait()
300 	dma_fence_put(entry->fence);  in syncobj_eventfd_entry_free()
322  * @fence: fence to encapsulate in the chain node
329 			   struct dma_fence *fence,  in drm_syncobj_add_point()  argument
336 	dma_fence_get(fence);  in drm_syncobj_add_point()
344 	dma_fence_chain_init(chain, prev, fence, point);  in drm_syncobj_add_point()
345 	rcu_assign_pointer(syncobj->fence, &chain->base);  in drm_syncobj_add_point()
354 	dma_fence_chain_for_each(fence, prev);  in drm_syncobj_add_point()
360  * drm_syncobj_replace_fence - replace fence in a sync object.
361  * @syncobj: Sync object to replace fence in
362  * @fence: fence to install in sync file.
364  * This replaces the fence on a sync object.
367 			       struct dma_fence *fence)  in drm_syncobj_replace_fence()  argument
373 	if (fence)  in drm_syncobj_replace_fence()
374 		dma_fence_get(fence);  in drm_syncobj_replace_fence()
378 	old_fence = rcu_dereference_protected(syncobj->fence,  in drm_syncobj_replace_fence()
380 	rcu_assign_pointer(syncobj->fence, fence);  in drm_syncobj_replace_fence()
382 	if (fence != old_fence) {  in drm_syncobj_replace_fence()
396  * drm_syncobj_assign_null_handle - assign a stub fence to the sync object
397  * @syncobj: sync object to assign the fence on
399  * Assign a already signaled stub fence to the sync object.
403 	struct dma_fence *fence = dma_fence_allocate_private_stub(ktime_get());  in drm_syncobj_assign_null_handle()  local
405 	if (!fence)  in drm_syncobj_assign_null_handle()
408 	drm_syncobj_replace_fence(syncobj, fence);  in drm_syncobj_assign_null_handle()
409 	dma_fence_put(fence);  in drm_syncobj_assign_null_handle()
416  * drm_syncobj_find_fence - lookup and reference the fence in a sync object
421  * @fence: out parameter for the fence
426  * Returns 0 on success or a negative error value on failure. On success @fence
427  * contains a reference to the fence, which must be released by calling
432 			   struct dma_fence **fence)  in drm_syncobj_find_fence()  argument
451 	*fence = drm_syncobj_fence_get(syncobj);  in drm_syncobj_find_fence()
453 	if (*fence) {  in drm_syncobj_find_fence()
454 		ret = dma_fence_chain_find_seqno(fence, point);  in drm_syncobj_find_fence()
458 			 * fence. To make sure the recipient gets  in drm_syncobj_find_fence()
459 			 * signalled, use a new fence instead.  in drm_syncobj_find_fence()
461 			if (!*fence)  in drm_syncobj_find_fence()
462 				*fence = dma_fence_get_stub();  in drm_syncobj_find_fence()
466 		dma_fence_put(*fence);  in drm_syncobj_find_fence()
481 		if (wait.fence) {  in drm_syncobj_find_fence()
499 	*fence = wait.fence;  in drm_syncobj_find_fence()
537  * @fence: if non-NULL, the syncobj will represent this fence
546 		       struct dma_fence *fence)  in drm_syncobj_create()  argument
568 	if (fence)  in drm_syncobj_create()
569 		drm_syncobj_replace_fence(syncobj, fence);  in drm_syncobj_create()
741 	struct dma_fence *fence = sync_file_get_fence(fd);  in drm_syncobj_import_sync_file_fence()  local
744 	if (!fence)  in drm_syncobj_import_sync_file_fence()
749 		dma_fence_put(fence);  in drm_syncobj_import_sync_file_fence()
753 	drm_syncobj_replace_fence(syncobj, fence);  in drm_syncobj_import_sync_file_fence()
754 	dma_fence_put(fence);  in drm_syncobj_import_sync_file_fence()
763 	struct dma_fence *fence;  in drm_syncobj_export_sync_file()  local
770 	ret = drm_syncobj_find_fence(file_private, handle, 0, 0, &fence);  in drm_syncobj_export_sync_file()
774 	sync_file = sync_file_create(fence);  in drm_syncobj_export_sync_file()
776 	dma_fence_put(fence);  in drm_syncobj_export_sync_file()
915 	struct dma_fence *fence, *tmp;  in drm_syncobj_transfer_to_timeline()  local
929 	fence = dma_fence_unwrap_merge(tmp);  in drm_syncobj_transfer_to_timeline()
931 	if (!fence) {  in drm_syncobj_transfer_to_timeline()
942 	drm_syncobj_add_point(timeline_syncobj, chain, fence, args->dst_point);  in drm_syncobj_transfer_to_timeline()
944 	dma_fence_put(fence);  in drm_syncobj_transfer_to_timeline()
956 	struct dma_fence *fence;  in drm_syncobj_transfer_to_binary()  local
963 				     args->src_point, args->flags, &fence);  in drm_syncobj_transfer_to_binary()
966 	drm_syncobj_replace_fence(binary_syncobj, fence);  in drm_syncobj_transfer_to_binary()
967 	dma_fence_put(fence);  in drm_syncobj_transfer_to_binary()
994 static void syncobj_wait_fence_func(struct dma_fence *fence,  in syncobj_wait_fence_func()  argument
1006 	struct dma_fence *fence;  in syncobj_wait_syncobj_func()  local
1009 	fence = rcu_dereference_protected(syncobj->fence,  in syncobj_wait_syncobj_func()
1011 	dma_fence_get(fence);  in syncobj_wait_syncobj_func()
1012 	if (!fence || dma_fence_chain_find_seqno(&fence, wait->point)) {  in syncobj_wait_syncobj_func()
1013 		dma_fence_put(fence);  in syncobj_wait_syncobj_func()
1015 	} else if (!fence) {  in syncobj_wait_syncobj_func()
1016 		wait->fence = dma_fence_get_stub();  in syncobj_wait_syncobj_func()
1018 		wait->fence = fence;  in syncobj_wait_syncobj_func()
1033 	struct dma_fence *fence;  in drm_syncobj_array_wait_timeout()  local
1060 	 * a syncobj with a missing fence and then never have the chance of  in drm_syncobj_array_wait_timeout()
1065 		struct dma_fence *fence;  in drm_syncobj_array_wait_timeout()  local
1069 		fence = drm_syncobj_fence_get(syncobjs[i]);  in drm_syncobj_array_wait_timeout()
1070 		if (!fence || dma_fence_chain_find_seqno(&fence, points[i])) {  in drm_syncobj_array_wait_timeout()
1071 			dma_fence_put(fence);  in drm_syncobj_array_wait_timeout()
1080 		if (fence)  in drm_syncobj_array_wait_timeout()
1081 			entries[i].fence = fence;  in drm_syncobj_array_wait_timeout()
1083 			entries[i].fence = dma_fence_get_stub();  in drm_syncobj_array_wait_timeout()
1086 		    dma_fence_is_signaled(entries[i].fence)) {  in drm_syncobj_array_wait_timeout()
1100 	 * fence is signaled prior to fence->ops->enable_signaling() being  in drm_syncobj_array_wait_timeout()
1115 			fence = entries[i].fence;  in drm_syncobj_array_wait_timeout()
1116 			if (!fence)  in drm_syncobj_array_wait_timeout()
1120 			    dma_fence_is_signaled(fence) ||  in drm_syncobj_array_wait_timeout()
1122 			     dma_fence_add_callback(fence,  in drm_syncobj_array_wait_timeout()
1125 				/* The fence has been signaled */  in drm_syncobj_array_wait_timeout()
1159 			dma_fence_remove_callback(entries[i].fence,  in drm_syncobj_array_wait_timeout()
1161 		dma_fence_put(entries[i].fence);  in drm_syncobj_array_wait_timeout()
1361 static void syncobj_eventfd_entry_fence_func(struct dma_fence *fence,  in syncobj_eventfd_entry_fence_func()  argument
1376 	struct dma_fence *fence;  in syncobj_eventfd_entry_func()  local
1379 	fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));  in syncobj_eventfd_entry_func()
1380 	ret = dma_fence_chain_find_seqno(&fence, entry->point);  in syncobj_eventfd_entry_func()
1381 	if (ret != 0 || !fence) {  in syncobj_eventfd_entry_func()
1382 		dma_fence_put(fence);  in syncobj_eventfd_entry_func()
1387 	entry->fence = fence;  in syncobj_eventfd_entry_func()
1393 		ret = dma_fence_add_callback(fence, &entry->fence_cb,  in syncobj_eventfd_entry_func()
1570 		struct dma_fence *fence = dma_fence_get_stub();  in drm_syncobj_timeline_signal_ioctl()  local
1573 				      fence, points[i]);  in drm_syncobj_timeline_signal_ioctl()
1574 		dma_fence_put(fence);  in drm_syncobj_timeline_signal_ioctl()
1613 		struct dma_fence *fence;  in drm_syncobj_query_ioctl()  local
1616 		fence = drm_syncobj_fence_get(syncobjs[i]);  in drm_syncobj_query_ioctl()
1617 		chain = to_dma_fence_chain(fence);  in drm_syncobj_query_ioctl()
1620 				dma_fence_get(fence);  in drm_syncobj_query_ioctl()
1624 				point = fence->seqno;  in drm_syncobj_query_ioctl()
1626 				dma_fence_chain_for_each(iter, fence) {  in drm_syncobj_query_ioctl()
1627 					if (iter->context != fence->context) {  in drm_syncobj_query_ioctl()
1644 		dma_fence_put(fence);  in drm_syncobj_query_ioctl()